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Annals of Surgical Oncology 8:311-318 (2001)
© 2001 Society of Surgical Oncology

ORIGINAL ARTICLES

p27kip1 Expression Is Associated With Tumor Response to Preoperative Chemoradiotherapy in Rectal Cancer

Giovanni Esposito, MD, Salvatore Pucciarelli, MD, Rita Alaggio, MD, Luciano Giacomelli, PhD, Elisabetta Marchiori, MD, Gaetano Antonio Iaderosa, MD, Maria Luisa Friso, MD, Paola Toppan, MD, Luigi Chieco-Bianchi, MD and Mario Lise, MD

From the Sections of Oncology (GE, LC-B), II Clinical Surgery (SP, EM, PT, ML), and Pathology (RA, LG, GAI) of the Department of Oncology and Surgery of the University of Padova; and the Molecular Diagnostic Oncology Service (GE, LC-B), and Division of Radiology (MLF) of the City Hospital of Padova; Padova, Italy.

Correspondence: Address correspondence and reprint requests to: Giovanni Esposito, MD, Servizio Citodiagnostica Molecolare Oncologica, Via Gattamelata, 64, 35128 - Padova, Italy; Fax: 39-049-8072854; E-mail: cmaltese{at}ux1.unipd.it


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Background: Our aim was to ascertain whether or not the response to preoperative chemoradiotherapy for rectal cancer is associated with p27kip1 and p53 protein expression.

Methods: Thirty-eight patients (27 male, 11 female) with a mean age of 59 years (age range 33–87) and stage II-III rectal cancer received preoperative chemoradiotherapy (45–50.4 Gy; 5-FU 350 mg/m2/day and leucovorin 10 mg/m2/day). Thirty-one underwent low anterior resection; seven underwent abdominoperineal excision. Endoscopic tumor biopsies, performed before adjuvant therapy, were evaluated for: histologic type, tumor differentiation, mitotic index, and p27kip1 and p53 protein expression which were immunohistochemically determined. p53 expression was graded as: a) absent or present in <=10% of tumor cells; b) present in 11–25%; c) present in 26–75%; and d) present in >75% of tumor cells. p27kip1 expression was assessed using both light microscopy (percent of stained cells x10 HPF) and cytometry with an image analysis workstation. Tumor response, ascertained with histology, was classified using a scale from 0 (no response) to 6 (complete pathologic response).

Results: The mitotic index for the endoscopic biopsies was low in 14 cases, moderate in 17 cases, and high in 7 cases. p53 protein expression was found in 21 (a), 3 (b), 3 (c), and 11 (d) cases. The mean percentage of cells expressing the p27kip1 protein was 34 (range 0–77.14%). A close correlation was found between cytometric and light microscopy findings for p27kip1 (r2 = 0.92, P = .0001). Tumor differentiation was good in 5 cases, poor in 2 cases, and moderate in the remaining 31 cases. While the response to adjuvant therapy was good/complete in 25 (65.78%) cases, it was absent/poor in 13 (34.21%) cases. Univariate analysis associated type of adjuvant therapy (chemoradiotherapy, P = .0428) and p27kip1 protein lower expression (P = .0148) with a poor response to adjuvant treatment. Stepwise linear regression found overexpression of p53 and p27kip1 and young age to be independent variables that were linked to a good response to adjuvant therapy.

Conclusions: Lack of p27kip1 and p53 protein expression in rectal cancer is associated with a poor response to preoperative adjuvant therapy.

Key Words: p27kip1 • p53 • Chemoradiotherapy • Rectal cancer


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
PATIENTS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Rectal carcinoma, one of the most frequent forms of cancer in Western countries, is not susceptible to radical surgery when diagnosed because of local or distant spread in about 20% of cases.1 After radical surgery, the five-year survival rate is 60% to 80% for stage II (T3-T4, N0) and 30% to 50% for stage III (any T, N+) patients.2

Over the last 50 years, no real improvement has been achieved in the survival percentages after resection. Because surgery alone cannot be considered curative for many stage II and III patients, adjuvant therapy is recommended in these cases. Several authors3–5 have observed a reduced local recurrence rate and an improved survival rate after radiotherapy.6 An improvement in survival rate has also been observed after radiotherapy and 5-fluorouracil-based chemotherapy.4,7,8

Further reduction in local and distant recurrences and an increase in survival rate may also be achieved by administering preoperative chemoradiotherapy.9–11 Neoadjuvant chemoradiotherapy allows tumor downstaging (size and local invasion reduction), with a consequently improved possibility for achieving curative sphincter-sparing surgery (low anterior resection rather than abdominoperineal resection) and an important effect on quality of life.12,13 The percentage for complete response to neoadjuvant therapy (i.e., no neoplasia on the surgical specimen) ranges from 5% to 14% in some studies, but is 35% in other studies.2,10,12,14–18 This discrepancy probably exists because of differences in the treatments given and in variations in intrinsic characteristics of each tumor. It is therefore important to identify biological parameters that will enable us to predict individually whether or not patients will respond to neoadjuvant chemotherapy, thus sparing potentially nonresponsive patients from unnecessary treatment.

Several authors have demonstrated that apoptosis is one of the mechanisms underlying chemoradiotherapy-induced tumor regression,19–21 with the response to adjuvant therapy due mainly to neoplastic cells’ ability to trigger the apoptotic cascade.22 The present study focused on two of several proteins involved in the regulation of apoptosis: the p53 and the p27kip1 proteins. Alterations in the p53 gene are found frequently in different types of tumors.23–28 In particular, p53 mutations have been found in 45% to 70% of carcinomas of the large bowel.29–32 The p53 gene is involved in the regulation of the cell cycle, in the repair of DNA, in cellular death through apoptosis, and, therefore, in the maintenance of genomic integrity. As a response to DNA damage, the p53 protein accumulates in the cell and causes the cell cycle to arrest in the G1 phase, thus allowing repair mechanisms to intervene before the alteration is fixed in the genome and transmitted to daughter cells.33,34 If this does not occur, p53 induces a "suicidal" response in the cell by activating apoptosis.35,36

In 1994, p27kip1 was identified as a member of the universal cyclin-dependent kinase inhibitor family, like p21cip1/waf1 and p57kip2.37–42 More recently, it has been suggested that this protein is the product of a putative tumor suppressor gene,42 that it regulates cell differentiation43 and drug resistance in solid tumors,44 and that it also promotes apoptosis.45

The present study’s aim was to establish whether or not the expression of p27kip1 and p53 proteins in tumor representative preoperative biopsies is correlated with a response to neoadjuvant-combined chemoradiotherapy, classified as the histological degree of tumor regression assessed on surgical specimens. Both proteins were also evaluated on surgical specimens in order to identify any variations in their expression in resected tumors after neoadjuvant therapy.


   PATIENTS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Patient Selection
Between March 1988 and March 1999 and after preoperative chemoradiotherapy, 79 consecutive patients with primary rectal adenocarcinoma of the middle and lower rectum underwent surgery at Clinica Chirurgica II, University of Padova. Criteria for giving neoadjuvant therapy were:

(1) histologically proven adenocarcinoma of the middle and lower rectum; (2) preoperative clinical TNM (tumor, node, metastasis) stage II-III; and (3) Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 2. Forty-one patients were excluded because preoperative endoscopic biopsies or radiotherapy had been performed elsewhere (n = 37) or because the biopsy was not sufficiently representative of the tumor (n = 4). The study group consisted of the remaining 38 patients (27 males, 11 females) with a mean age of 59 years (range, 33–87 years). Thirty-six underwent surgery between 1994 and 1999 and two between 1988 and 1993.

Preoperative Staging and Treatment
The preoperative clinical (pelvic CT scan, transrectal and liver ultrasonography, and chest x-ray) and postoperative pathological stages were defined using the TNM stage classification system.46 The clinical stage (cTNM) was II in 11 cases and III in 27 cases.

Thirty-three patients underwent preoperative combined chemoradiotherapy; five underwent radiotherapy alone. External beam radiotherapy was administered by a linear accelerator x-ray (10 MV). The four beam "box" technique was used, with the upper border extending to L-5/S-1. The total dose received was 45 to 50.4 Gy (1.8 Gy/day per fraction). Thirty-three patients received concomitant chemotherapy (5-fluorouracil 350 mg/m2/day and leucovorin 10 mg/m2/day), administered in bolus, on days 1 through 5 and 29 through 33 of radiotherapy.

The surgical procedures performed were: low anterior resection with colorectal or coloanal anastomosis (n = 31) and abdominoperineal resection (n = 7). The mean time interval between the end of neoadjuvant treatment and surgery was 38 days (range 10–66).

Histology
In each case, the preoperative biopsies (obtained before neoadjuvant therapy) and the surgical specimens were analyzed. Parameters considered were: histological type, tumor grading, and mitotic index. The mitotic index was considered low when mitotic figures were <=2/HPF, moderate when they were from >2 to <=5, and high when mitoses were >5/HPF.

At least six samples of the tumor, or the entire fibrotic area in which regression was suspected, were examined microscopically to evaluate the degree of regression. Histological determination of tumor response on surgical specimens was performed with a seven categories scoring model, which was a modified version of the system proposed by Dworak et al.47 (Table 1). For statistical purposes, the seven classes were dichotomized as good/complete response (grades 4–6) and absent/poor response (grades 0–3). Consequently, there was one group (0-3) with (apart from concomitant necrotic or fibrotic areas) a vital neoplastic component that could reach 70%, and another (4-6), with a reduction in the neoplasia, of at least 60%.


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  		TABLE 1. Histopathological classification of tumor response to chemoradiotherapy
 
Immunohistochemistry
In each case, one slide corresponding to the most representative part of the tumor was chosen to make an immunohistochemical evaluation of p27kip1 and p53 protein expression.

Formalin-fixed, paraffin-embedded sections were deparaffinized and rehydrated. p27kip1 expression was analyzed using an anti-p27 monoclonal antibody (clone 57: Transduction Laboratories, Lexington, KY) in a 1:600 dilution at room temperature. p53 was detected by the monoclonal antibody PAb 1801 (Ab-2: Oncogene Research Products, Cambridge, MA) in a 1:100 dilution at 4°C. For each antibody, a step of heat-induced antigen retrieval was performed at 750W in a microwave oven using three 5-minute cycles for PAb 1801 and four 5-minute cycles for the anti-p27 antibody; then, an overnight incubation was made. After incubation with the primary antibodies, immunostaining was performed using the avidin-biotin-peroxidase complex technique and 3–3' diaminobenzidine as chromogen (VECTASTAIN ABC kit and DAB kit: Vector Laboratories, Burlingame, CA). Finally, the sections were counterstained with Mayer’s hematoxylin.

p53 and p27kip1 Scoring
p53 protein expression was graded as: (1) absent or present in <=10% of tumor cells; (2) present in 11–25%; (3) present in 26–75%, or (4) present in >75% of tumor cells.

p27kip1 protein expression was assessed using two modalities: (1) light microscopy (by calculating the percentage of stained cells over the total cells x10 HPF) using an eye-piece integration grid (preoperative biopsies and surgical specimens); (2) blindly, with a light-microscope connected to an image analysis system, with the final determination (i.e., the percentage of p27kip1 labeled cells) made as an area fraction (i.e., the percentage of nuclei with a positive immunostaining area against the total nuclear area) on preoperative biopsies only.

In all cases, 5 to 10 fields were evaluated at 20 x magnification. Measurements were made using the CIRES workstation (Zeiss, Jena, Germany), consisting of a light microscope (Axioscope model, Zeiss, Jena, Germany) connected to a 3-CCD color video camera (model KY-F55BE, JVC, Japan). Köhler illumination was used to reduce stray light, and images were analyzed using a PC with a frame grabber (Kontron, Eching, Germany).

Statistical Analysis
Univariate analysis was performed using the one-way analysis of variance. Linear regression was used for multivariate analysis. The most significant subset of variables, first selected using a stepwise procedure, was analyzed to measure any correlation. A P value of <= .05 was considered statistically significant.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Downstaging
Pathologic TNM staging on surgical specimens showed a downstaging of tumors compared to clinical TNM: 9 cases were classified as stage I (none in clinical staging), 13 as stage II (11 in clinical staging), 7 as stage III (27 in clinical staging), and 3 as stage IV (none in clinical staging). Six cases (15.78%), in which no tumor was found on the surgical specimen, were considered completely responsive to chemoradiotherapy.

Histology
No differences were found between tumor differentiation assessed in preoperative biopsies and that in surgical specimens. In preoperative biopsies, tumors were graded as well differentiated in 5 cases, moderately differentiated in 31 cases, and poorly differentiated in 2 cases. The surgical specimens were well differentiated in 1 case, moderately differentiated in 30 cases, and poorly differentiated in 1 case. The mitotic index in preoperative biopsies was low in 14 cases, moderate in 17 cases, and high in 7 cases. In surgical specimens, the mitotic index was found to be low in 11 cases, moderate in 17 cases, and high in 4 cases.

p53 and p27kip1 Expression
In preoperative biopsies, p53 protein expression was not detected in 21 cases (55.26%), whereas it showed different degrees of positivity in 17 cases (44.73%): 11–25% of immunostained tumor cells in 3 cases, 26–75% in 3 cases, and >75% in 11 cases. p27kip1 protein expression was present in 34 cases and completely absent in 4 cases. The mean percentage of cancer cells expressing p27kip1 at the light-microscopy count was 34 (range 0–77.14%). A close correlation was found between cytometric and light-microscopy findings for p27kip1 (r2 = 0.92; P = .0001) (Fig. 1).



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  		FIG. 1. p27kip1 expression in preoperative biopsies: concordance between light microscopy and cytometry findings.

 
When comparing the preoperative and postoperative specimens, changes were found in the levels of expression of both p53 and p27kip1. For p53 expression, a shift from negativity to strong positivity was found upon immunostaining in three cases. For p27kip1 expression, a shift was found (i.e., a difference of at least 20% of immunostained neoplastic cells counted) toward a reduced expression in four cases and toward an increased expression in six cases (Table 2).


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  		TABLE 2. Variations between p27kip1 expression in preoperative biopsies and surgical specimens
 
The histological degree of response to neoadjuvant therapy, scored using a modified version of the Dworak tumor regression grade system, is shown in Fig. 2. The response was good/complete in 25 cases (65.78%) and absent/poor in 13 (34.21%). The mean (Standard Error) expression of p27kip1 was respectively 42.84% (3.74) in the former group and 25.08% (6.56) in the latter.



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  		FIG. 2. Tumor response and percent of p27kip1 expressing cells in pretreatment biopsies.

 
Univariate analysis found that type of neoadjuvant therapy (combined chemoradiotherapy vs. radiotherapy alone; P = .0428) and p27kip1 degree of expression (P = .0148) were associated with response to treatment. No other variables were associated with tumor response to the preoperative therapy (Table 3). Multivariate analysis found that p53 and p27kip1 expression and young age to be independent variables linked to a good response to neoadjuvant therapy (Table 4.).


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  		TABLE 3. Variables associated with tumor response to neoadjuvant therapy upon univariate analysis
 

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  		TABLE 4. Regression coefficients of variables associated with tumor response to neoadjuvant therapy upon multivariate regression analysis
 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
Neoadjuvant therapy for carcinoma of the middle and lower rectum, with radiotherapy only or with combined chemoradiotherapy, can induce a tumor downstaging, thus allowing more sphincter-saving procedures to be performed, and also ensuring an encouraging oncologic outcome.48 However, in about 30% of the cases the response to therapy is poor or absent. The identification of factors prognosticating response to neoadjuvant therapy may allow a more accurate selection of patients—sparing those with nonresponsive tumors from neoadjuvant therapy, or allowing those patients to undergo alternative treatment with different drugs.

Therefore, with the aim of identifying any correlation between tumor response as histologically determined on surgical specimens and the features observable in preoperative biopsies, we analyzed the behavior of p53 and p27kip1. Both are involved in the inhibition of the cell cycle and the induction of apoptosis. For this purpose, a careful evaluation was made of the histological degree of tumor regression. Our grading system was based on the identification of fibrotic changes and necrosis in preoperative and surgical specimens in an effort to distinguish between the desmoplasia and necrosis characteristic of the neoplasia and the effect of therapy. Moreover, we found it important that the entire neoplastic area be embedded for regression in order to be considered complete. In six cases classified as grade 5, there were only microscopic foci of residual neoplasia that might have remained undetected, thus potentially leading to an erroneous diagnosis of complete regression.

For p27kip1 expression scoring on biopsies, light-microscope evaluation and the image analysis system, which were used blind, gave a good concordance of data. This suggested that the imaging analysis system, which is less time-consuming, could be used on a more widespread scale.

Both univariate and multivariate analysis found a significant correlation between the increase in the percentage of tumor cells expressing p27kip1 on biopsies and the increase in the histological degree of response to therapy (Fig. 3).



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  		FIG. 3. A-B: High expression of p27kip1 in a preoperative biopsy (A) with an almost histologically complete (grade 5) response to neoadjuvant therapy, as showed in the surgical specimen with only isolated neoplastic glands (arrowhead) enclosed in a fibrotic stroma (B). C-D: preoperative biopsy with diffuse negativity for p27kip1 (C); note the internal positive control represented by infiltrating lymphocytes (arrowhead), and absent response to neoadjuvant therapy in surgical specimen (D). A-C: immunohistochemical analysis - Mayer’s hematoxylin counterstaining - original magnification 20x. B-D: H&E staining - original magnification 20x.

 
Data reported in literature on the relation between p27kip1 and apoptosis, and response to therapy, are contradictory. Some authors45,49,50 found in vitro that high p27kip1 levels, induced by adenovirus vectors, led to an arrest in growth as well as an increase in apoptosis in various cell lines from different species and tissues of various origin. In vitro studies by other authors44,51 found p27kip1 overexpression to induce a resistance to some drugs through the inhibition of apoptosis. On the other hand, there is a growing body of in vivo evidence showing a close correlation between p27kip1 expression and apoptosis. A strong correlation has been found between p27kip1 expression and the apoptotic index by Fujieda et al.52 in 60 oral and oropharyngeal squamous cell carcinoma patients, by Othani et al.54 in 225 non-early stage gastric carcinoma patients,53 and by Wu et al in 181 breast cancer patients. In the last study, p27kip1 was also found to be predictive of chemotherapy benefit. Our finding of an association between p27kip1 and response to preoperative chemoradiotherapy may therefore be explained by the pro-apoptotic activity of p27kip1.

However, from a clinical viewpoint, it would be useful to establish a reliable p27kip1 cut-off value for the prediction of the response to neoadjuvant therapy. Interestingly, when arbitrarily stratifying p27kip1 expression as absent, present in <50%, and present in more than 50% of neoplastic cells, we still found a correlation between expression and response. Moreover, upon histological evaluation, all four tumors that were negative for p27kip1 expression presented a regression that was classified as absent/poor. These findings should, however, be confirmed in a larger patient population.

In several different tumor types, gene mutations have been found for p53 and other molecular prognostic factors, whereas it has been observed that p27 gene mutations are not present in a variety of human tumors.54 The levels of p27kip1 expression seem to be regulated mainly at a posttranscriptional level, via a ubiquitin-proteasome mediated proteolysis mechanism.55–57 These observations give a reliable meaning to the immunohistochemical data for p27kip1.

A more vexing issue is the interpretation of data for p53. Although univariate analysis found no association between p53 expression and tumor response to neoadjuvant therapy, multivariate analysis found that p53 expression on preoperative biopsies (together with the p27kip1 percentage of expression and young age) was predictive of a better response to therapy. Data reported in the literature are contradictory: whereas some authors report an association between p53 overexpression and a lower response rate to treatment,58,59 others do not.22

The antibodies normally used recognize stabilized forms of the p53 molecule and are not specific for mutant forms. It is well-known that mutated forms of p53 are generally stabilized with a longer half-life than the wild-type protein; this makes them detectable by immunohistochemistry. The immunohistochemical detection of protein is, therefore, considered synonymous with protein mutation; however, this is not necessarily the case (i.e., stabilization can depend on an interaction with other cellular oncogene products, or viral molecules).60,61 Clearly, an analysis of the p53 gene is required for an adequate understanding of the meaning of p53 protein expression.

Two hypotheses may be put forward to explain our findings: (1) the presence of a mutated protein that, however, maintains its pro-apoptotic activity,62–64 or (2) the presence of a stabilized wild-type protein responding to DNA damage.

After comparing p53 and p27kip1 expression in preoperative and surgical specimens, we found that there was a shift in three cases from p53 negativity in preoperative biopsies to strong positivity in posttherapy samples. This was probably related to p53 gene activation subsequent to DNA damage induced by therapy, or it may have been due to new gene mutations. For p27kip1, differences were found in 10 cases: the posttherapy specimens showed a significantly reduced expression in four cases and an increase in six cases with respect to corresponding preoperative biopsies. As with p53, therapy-induced damage may affect p27kip1 expression. However, our data confirm the need to exclude patients undergoing preoperative therapy from studies performed on surgical samples.

In conclusion, we found a close correlation between the level of p27kip1 expression and the degree of tumor regression upon histological evaluation of surgical specimens. This relationship, if confirmed in larger series, may become a useful tool for identifying subgroups of patients more likely to benefit from neoadjuvant therapy.

The finding for the p53 protein is controversial, calling above all for a knowledge of the type of protein expressed.


   Acknowledgments
 
The authors thank Dr. Carlo Schievano for the statistical analysis, Mrs. Dina Pozza for technical assistance, Mr. Pierantonio Gallo for artwork, and Mrs. Sara Pearcey for assistance with English. This study was supported in part by a grant from Associazione Italiana per la Ricerca sul Cancro (AIRC), Milano, Italy.

Received for publication July 7, 2000. Accepted for publication December 4, 2000.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 PATIENTS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. National Cancer Institute statisticians, SEER Cancer Statistics Review, 1973-1995. Bethesda, MD: National Cancer Institute, 1998.
  2. Chari RS, Tyler DS, Anscher MS, et al. Preoperative radiation and chemotherapy in the treatment of adenocarcinoma of the rectum. Ann Surg 1995; 221: 778–86.[Medline]
  3. Gerard A, Buyse M, Nordlinger B, et al. Preoperative radiotherapy as adjuvant treatment in rectal cancer. Final results of a randomized study of the European Organization for Research and Treatment of Cancer (EORTC). Ann Surg 1988; 208: 606–14.[Medline]
  4. Fisher B, Wolmark N, Rockette H, et al. Postoperative adjuvant chemotherapy or radiation therapy for rectal cancer: results from NSABP protocol R-01. J Natl Cancer Inst 1988; 80: 21–9.[Abstract/Free Full Text]
  5. Cedemark B. The Stockholm II trial on preoperative short-term radiotherapy in operable rectal carcinoma: a prospective randomized trial. Proc Am Soc Clin Oncol 1994; 13: 198–201.
  6. Swedish Rectal Cancer Trial. Improved survival with preoperative radiotherapy in resectable rectal cancer. N Engl J Med 1997;336:980–7.
  7. Krook JE, Moertel CG, Gunderson LL, et al. Effective surgical adjuvant therapy for high-risk rectal carcinoma. N Engl J Med 1991; 324: 709–15.[Abstract]
  8. Moertel CG, Fleming TR, Macdonald JS, et al. Fluorouracil plus levamisole as effective adjuvant therapy after resection of stage III colon carcinoma: a final report. Ann Intern Med 1985; 122: 321–6.[CrossRef]
  9. Boulis-Wassif S, Gerard A, Loygue J, Camelot D, Buyse M, Duez N. Final results of a randomized trial on the treatment of rectal cancer with preoperative radiotherapy alone or in combination with 5-fluorouracil, followed by radical surgery. Trial of the European Organization on Research and Treatment of Cancer Gastrointestinal Tract Cancer Cooperative Group. Cancer 1984; 53: 1811–8.[CrossRef][Medline]
  10. Minsky B, Cohen A, Enker W, et al. Preoperative 5-fluorouracil, low-dose leucovorin, and concurrent radiation therapy for rectal cancer. Cancer 1994; 73: 273–80.[CrossRef][Medline]
  11. Grann A, Minsky BD, Cohen AM, et al. Preliminary results of preoperative 5-fluorouracil, low-dose leucovorin, and concurrent radiation therapy for clinically resectable T3 rectal cancer. Dis Colon Rectum 1997; 40: 515–22.[CrossRef][Medline]
  12. Hyams DM, Mamounas EP, Petrelli N, et al. A clinical trial to evaluate the worth of preoperative multimodality therapy in patients with operable carcinoma of the rectum: a progress report of National Surgical Breast and Bowel Project Protocol R-03. Dis Colon Rectum 1997; 40: 131–9.[CrossRef][Medline]
  13. Mohiuddin M, Regine WF, Marks GJ, Marks JW. High-dose preoperative radiation and the challenge of sphincter-preservation surgery for cancer of the distal 2 cm of the rectum. Int J Radiat Oncol Biol Phys 1998; 40: 569–74.[CrossRef][Medline]
  14. Meade PG, Blatchford GJ, Thorson AG, Christensen MA, Ternent CA. Preoperative chemoradiation downstages locally advanced ultrasound-staged rectal cancer. Am J Surg 1995; 170: 609–12.[CrossRef][Medline]
  15. Berard P, Papillon J. Role of pre-operative irradiation for anal preservation in cancer of the low rectum. World J Surg 1992; 16: 502–9.[CrossRef][Medline]
  16. Rouanet P, Fabre JM, Dubois JB, et al. Conservative surgery for low rectal carcinoma after high-dose radiation. Ann Surg 1995; 221: 67–73.[Medline]
  17. Berger C, de Muret A, Garaud P, et al. Preoperative radiotherapy (RT) for rectal cancer: predictive factors of tumor downstaging and residual tumor cell density (RTCD): prognostic implications. Int J Radiat Oncol Biol Phys 1997; 37: 619–27.[CrossRef][Medline]
  18. Forrett-Kaminsky MC, Conroy T, Luporsi E, et al. Prognostic implications of downstaging following preoperative radiation therapy for operable T3-T4 rectal cancer. Int J Radiat Oncol Biol Phys 1998; 42: 935–41.[CrossRef][Medline]
  19. Staunton MJ, Gaffney EF. Apoptosis: basic concepts and potential significance in human cancer. Arch Pathol Lab Med 1998; 122: 310–9.[Medline]
  20. Martin SJ, Green DR. Apoptosis as a goal of cancer therapy. Curr Opin Oncol 1994; 6: 616–21.[Medline]
  21. Lowe SW, Ruley HE, Jacks T, Housman DE. p53-dependent apoptosis modulates the cytotoxicity of anticancer agents. Cell 1993; 74: 957–67.[CrossRef][Medline]
  22. Scott N, Hale A, Deakin M, et al. A histopathological assessment of the response of rectal adenocarcinoma to combination chemo-radiotherapy: relationship to apoptotic activity, p53 and bcl-2 expression. Eur J Surg Oncol 1998; 24: 169–73.[CrossRef][Medline]
  23. Hong SI, Hong WS, Jang JJ, et al. Alterations of p53 gene in primary gastric cancer tissues. Anticancer Res 1994; 14: 1251–5.[Medline]
  24. Scarpa A, Capelli P, Mukai K, et al. Pancreatic adenocarcinomas frequently show p53 gene mutations. Am J Pathol 1993; 142: 1534–43.[Abstract]
  25. Bertorelle R, Esposito G, Del Mistro A, et al. Association of p53 gene and protein alterations with metastases in colorectal cancer. Am J Surg Pathol 1995; 19: 463–71.[Medline]
  26. Yamaguchi A, Kurosaka Y, Fushida S, Kanno M, Yonemura Y, Miwa K, Miyazaki I. Expression of p53 protein in colorectal cancer and its relationship to short-term prognosis. Cancer 1992; 70: 2778–84.[CrossRef][Medline]
  27. Patel DD, Bhatavdekar JM, Chikhlikar PR, et al. Node negative breast carcinoma: hyperprolactinemia and/or overexpression of p53 as an independent predictor of poor prognosis compared to newer and established prognosticators. J Surg Oncol 1996; 62: 86–92.[CrossRef][Medline]
  28. Cordon-Cardo C, Sheinfeld J, Dalbagni G. Genetic studies and molecular markers of bladder cancer. Semin Surg Oncol 1997; 13: 319–27.[CrossRef][Medline]
  29. Bell SM, Scott N, Cross D, et al. Prognostic value of p53 overexpression and c-Ki-ras gene mutations in colorectal cancer. Gastroenterology 1993; 104: 57–64.[Medline]
  30. Poller DN, Baxter KJ, Shepherd NA. p53 and Rb1 protein expression: are they prognostically useful in colorectal cancer?. Br J Cancer 1997; 75: 87–93.[Medline]
  31. Ahnen DJ, Feigl P, Quan G, et al. Ki-ras mutation and p53 overexpression predict the clinical behavior of colorectal cancer: a Southwest Oncology Group study. Cancer Res 1998; 58: 1149–58.[Abstract/Free Full Text]
  32. Belluco C, Guillem JG, Kemeny N, et al. p53 nuclear protein overexpression in colorectal cancer: a dominant predictor of survival in patients with advanced hepatic metastases. J Clin Oncol 1996; 14: 2696–701.[Abstract/Free Full Text]
  33. Kastan MB, Onyekwere O, Sidransky D, Vogelstein B, Craig RW. Participation of p53 protein in the cellular response to DNA damage. Cancer Res 1991; 51: 6304–11.[Abstract/Free Full Text]
  34. Kuerbitz SJ, Plunkett BS, Walsh WV, Kastan MB. Wild-type p53 is a cell cycle checkpoint determinant following irradiation. Proc Natl Acad Sci U S A 1992; 89: 7491–5.[Abstract/Free Full Text]
  35. Clarke AR, Purdie CA, Harrison DJ, et al. Thymocyte apoptosis induced by p53-dependent and independent pathways. Nature 1993; 362: 849–52.[CrossRef][Medline]
  36. Lowe SW, Schmitt EM, Smith SW, Osborne BA, Jacks T. p53 is required for radiation-induced apoptosis in mouse thymocytes. Nature 1993; 362: 847–9.[CrossRef][Medline]
  37. Polyak K, Lee MH, Erdjument-Bromage H, et al. Cloning of p27kip1, a cyclin-dependent kinase inhibitor and a potential mediator of extracellular antimitogenic signals. Cell 1994; 78: 59–66.[CrossRef][Medline]
  38. Toyoshima H, Hunter T. p27, a novel inhibitor of G1 cyclin-Cdk protein kinase activity, is related to p21. Cell 1994; 78: 67–74.[CrossRef][Medline]
  39. Slingerland JM, Hengst L, Pan CH, Alexander D, Stampfer MR, Reed SI. A novel inhibitor of cyclin-Cdk activity detected in transforming growth factor beta-arrested epithelial cells. Mol Cell Biol 1994; 14: 3683–94.[Abstract/Free Full Text]
  40. Sherr CJ, Roberts JM. Inhibitors of mammalian G1 cyclin-dependent kinases. Genes Dev 1995; 9: 1149–63.[Free Full Text]
  41. Sherr CJ. Cancer cell cycles. Science 1996; 274: 1672–7.[Abstract/Free Full Text]
  42. Fero ML, Rivkin M, Tasch M, et al. A syndrome of multiorgan hyperplasia with features of gigantism, tumorigenesis, and female sterility in p27(Kip1)-deficient mice. Cell 1996; 85: 733–44.[CrossRef][Medline]
  43. Durand B, Gao FB, Raff M. Accumulation of the cyclin-dependent kinase inhibitor p27/Kip1 and the timing of oligodendrocyte differentiation. EMBO J 1997; 16: 306–17.[CrossRef][Medline]
  44. St. Croix B, Florenes VA, Rak JW, Flanagan M, Bhattacharya N, Slingerland JM, Kerbel RS. Impact of the cyclin-dependent kinase inhibitor p27kip1 on resistance of tumor cells to anticancer agents. Nat med 1996; 2: 1204–10.[CrossRef][Medline]
  45. Katayose Y, Kim M, Rakkar AN, Li Z, Cowan KH, Seth P. Promoting apoptosis: a novel activity associated with the cyclin-dependent kinase inhibitor p27. Cancer Res 1997; 57: 5441–5.[Abstract/Free Full Text]
  46. AJCC American Joint Committee on Cancer. Colon and Rectum. In: Fleming ID, Cooper JS, Henson DE, et al, eds. AJCC Cancer Staging Manual. 5th ed. Philadelphia: Lippincott-Raven, 1997:83–90.
  47. Dworak O, Keilholz L, Hoffmann A. Pathological features of rectal cancer after preoperative radiochemotherapy. Int J Colorectal Dis 1997; 12: 19–23.[CrossRef][Medline]
  48. Pucciarelli S, Friso ML, Toppan P, et al. Preoperative combined radiotherapy and chemotherapy for middle and lower rectal cancer: preliminary results. Ann Surg Oncol 2000; 7: 38–44.[Abstract]
  49. Wang X, Gorospe M, Huang Y, Holbrook NJ. p27Kip1 overexpression causes apoptotic death of mammalian cells. Oncogene 1997; 15: 2991–7.[CrossRef][Medline]
  50. Schreiber M, Muller WJ, Singh G, Graham FL. Comparison of the effectiveness of adenovirus vectors expressing cyclin kinase inhibitors p16 INK4A, p18INK4C, p19INK4D, p21WAF1/CIP1 and p27KIP1 in inducing cell cycle arrest, apoptosis and inhibition of tumorigenicity. Oncogene 1999; 18: 1663–76.[CrossRef][Medline]
  51. Eymin B, Haugg M, Droin N, Sordet O, Dimanche-Boitrel MT, Solary E. p27Kip1 induces drug resistance by preventing apoptosis upstream of cytochrome c release and procaspase-3 activation in leukemic cells. Oncogene 1999; 18: 1411–8.[CrossRef][Medline]
  52. Fujieda S, Inuzuka M, Tanaka N, et al. Expression of p27 is associated with Bax expression and spontaneous apoptosis in oral and oropharyngeal carcinoma. Int J Cancer 1999; 84: 315–20.[CrossRef][Medline]
  53. Ohtani M, Isozaki H, Fujii K, et al. Impact of the expression of cyclin-dependent kinase inhibitor p27Kip1 and apoptosis in tumor cells on the overall survival of patients with non-early stage gastric carcinoma. Cancer 1999; 85: 1711–8.[CrossRef][Medline]
  54. Wu J, Shen ZZ, Lu JS, et al. Prognostic role of p27Kip1 and apoptosis in human breast cancer. Br J Cancer 1999; 79: 1572–8.[CrossRef][Medline]
  55. Kawamata N, Morosetti R, Miller CW, et al. Molecular analysis of the cyclin-dependent kinase inhibitor gene p27/Kip1 in human malignancies. Cancer Res 1995; 55: 2266–9.[Abstract/Free Full Text]
  56. Pagano M, Tam SW, Theodoras AM, et al. Role of the ubiquitin-proteasome pathway in regulating abundance of the cyclin-dependent kinase inhibitor p27. Science 1995; 269: 682–5.[Abstract/Free Full Text]
  57. Hengst L, Reed SI. Translational control of p27Kip1 accumulation during the cell cycle. Science 1996; 271: 1861–4.[Abstract]
  58. Brett MC, Pickard M, Green B, et al. p53 protein overexpression and response to biomodulated 5-fluorouracil chemotherapy in patients with advanced colorectal cancer. Eur J Surg Oncol 1996; 22: 182–5.[CrossRef][Medline]
  59. Tannapfel A, Nüsslein S, Fietkau R, Katalinic A, Köckerling F, Wittekind C. Apoptosis, proliferation, bax, bcl-2 and p53 status prior to and after preoperative radiochemotherapy for locally advanced rectal cancer. Int J Radiat Oncol Biol Phys 1998; 41: 585–91.[CrossRef][Medline]
  60. Momand J, Zambetti GP, Olson DC, George D, Levine AJ. The mdm-2 oncogene product forms a complex with the p53 protein and inhibits p53-mediated transactivation. Cell 1992; 69: 1237–45.[CrossRef][Medline]
  61. Levine AJ, Momand J, Finlay CA. The p53 tumour suppressor gene. Nature 1991; 351: 453–6.[CrossRef][Medline]
  62. Bissonnette N, Wasylyk B, Hunting DJ. The apoptotic and transcriptional transactivation activities of p53 can be dissociated. Biochem Cell Biol 1997; 75: 351–8.[CrossRef][Medline]
  63. Gullouf C, Rosselli F, Sjin RT, Moustacchi E, Hoffman B, Liebermann DA. Role of a mutant p53 protein in apoptosis: characterization of a function independent of transcriptional trans-activation. Int J Oncol 1998; 13: 107–14.[Medline]
  64. Saller E, Tom E, Brunori M, Otter M, Estreicher A, Mack DH, Iggo R. Increased apoptosis induction by 121F mutant p53. EMBO J 1999; 18: 4424–37.[CrossRef][Medline]



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