10.1245/ASO.2006.10.012
Annals of Surgical Oncology 13:238-244 (2006)
© 2006 Society of Surgical Oncology
The Influence of Biologic Factors on the Surgical Decision in Advanced Neuroblastoma
Wen-Ming Hsu, MD, PhD1,
Yung-Ming Jen, MD2,
Hsinyu Lee, PhD3,
Min-Liang Kuo, PhD4,
Po-Nien Tsao, MD, PhD5,
Chiung-Nien Chen, MD, PhD1,
Dar-Ming Lai, MD1,
Ming-Tsan Lin, MD, DMSc1,
Hong-Shiee Lai, MD, PhD1,
Wei-Jao Chen, MD, MPH, DMSc1 and
Fon-Jou Hsieh, MD6
1 Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, #7 Chung-Shan South Road, Taipei 100, Taiwan
2 Department of Pathology, National Taiwan University Hospital and National Taiwan University College of Medicine, #7 Chung-Shan South Road, Taipei 100, Taiwan
3 Department of Life Science and Institute of Zoology, National Taiwan University, #1, Sec. 4, Roosevelt Road, Taipei 100, Taiwan
4 Institute of Toxicology, National Taiwan University College of Medicine, #1, Sec. 1, Jen-Ai Road, Taipei 100, Taiwan
5 Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, #7 Chung-Shan South Road, Taipei 100, Taiwan
6 Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, #7 Chung-Shan South Road, Taipei 100, Taiwan
Correspondence: Address correspondence and reprint requests to: Fon-Jou Hsieh, MD; E-mail: fjhsieh{at}ha.mc.ntu.edu.tw.
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ABSTRACT
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Background: Molecular markers greatly affect the outcome of neuroblastoma. This study evaluated the influence of Trk-A and myelocytomatosis viral-related oncogene, neuroblastoma-derived (MYCN) on the role of surgery in advanced neuroblastoma.
Methods: Ten stage 3 and 35 stage 4 neuroblastoma patients were included. Tumor resection was classified into gross total resection (GTR) and incomplete resection. Patients were classified into three biological risk groups according to Trk-A expression and myelocytomatosis viral-related oncogene, neuroblastoma-derived (MYCN) status in tumor tissues studied by immunohistochemistry and fluorescence in situ hybridization, respectively: low risk (positive Trk-A and normal MYCN), intermediate risk (negative Trk-A and normal MYCN), and high risk (positive or negative Trk-A and MYCN amplification). The effect of tumor resection on prognosis was studied and stratified according to the risk grouping.
Results: GTR was achieved in 21 patients (46.7%) with a higher complication rate (33% vs. 8% in the incomplete resection group, P = .036). GTR was easier to achieve in low-risk tumors than in intermediate- or high-risk tumors (12 of 13, 4 of 17, and 5 of 15, respectively; P < .001). GTR predicted a favorable prognosis for intermediate-risk patients (P = .037; log-rank test), but not for low- or high-risk patients because of the overall favorable and poor prognosis, respectively.
Conclusions: GTR carries a potentially higher possibility of complication. Although GTR can be achieved easily in low-risk neuroblastoma patients with a favorable prognosis, surgeons should do their best to achieve GTR for intermediate-risk patients to improve outcome. Nevertheless, sacrificing vital organs to achieve GTR for high-risk patients is not justified.
Key Words: Neuroblastoma Surgery Trk-A MYCN
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INTRODUCTION
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Neuroblastoma (NB) is an embryonic cancer of the postganglionic sympathetic nervous system that most commonly arises in the adrenal gland. It is one of the most common pediatric cancers, with an incidence of 8.0 per million per year,1 and 96% of cases occur before the age of 10 years.2 Clinical and biological studies have discriminated NB into at least two distinct entities.3,4 One, favorable NB, is characterized genetically by near-triploid karyotypes with whole chromosome gains. These tumors are usually localized and frequently seen in patients <1 year of age or are detected by mass screening. The favorable NBs either regress spontaneously or differentiate into benign ganglioneuromas and hence lead to a good outcome with minimal or even no treatment. The other entity, unfavorable NB, is characterized by diploid karyotypes with structural changes, including deletion of 1p or 11q, unbalanced gain of 17q, and/or amplification of the myelocytomatosis viral-related oncogene, neuroblastoma-derived (MYCN) protooncogene. Patients with unfavorable NBs are usually older than 1 year of age and have advanced stages of disease and a very poor prognosis, even with aggressive treatment. These lines of evidence suggest that a more detailed understanding of the clinical and biological characteristics of NB may allow for a more appropriate intensity of therapy for these tumors. Indeed, recent progress in biological and genetic understanding of NB has led to risk-related therapy to improve therapeutic outcomes and avoid unnecessary treatments.5
For decades, there has been debate regarding the role of surgery in NB, especially in advanced NB. Surgical resection alone can provide adequate treatment for early-stage disease.6 However, the importance of tumor resection as a therapeutic maneuver in the treatment of advanced NB remains controversial. Some investigators have reported that gross total resection (GTR) of tumors improves the survival rate in advanced stages,7,8 whereas others have not found any improvement with GTR.9,10 Most of these studies did not take into consideration the effect of biological factors of NB on the outcome of aggressive surgery, but considered only the clinical factors of disease stage and the patients age. Biological factors, such as MYCN (a transcription factor) and Trk-A (a nerve growth factor receptor), have great influence on the tumor behavior of NB and the patients outcome.11,12 NBs with MYCN amplification usually progress rapidly and have a very poor outcome,11 whereas tumors with high levels of Trk-A expression are susceptible to tumor differentiation or regression and have a favorable outcome.12 Neglecting these biological factors in the treatment of NB may misrepresent the true role of surgery in therapeutic strategies. In this study, we evaluated the effect of the biological factors MYCN and Trk-A on the outcome after GTR in advanced NB with the aim of determining the role of GTR in different biological groups of NBs.
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MATERIALS AND METHODS
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Patients and Treatment
From December 1990 to December 2002, 45 advanced-stage NB patients treated at National Taiwan University Hospital who had complete follow-up data were included in this study. Thirty-five patients had stage 4 tumors, and the other 10 had stage 3 tumors according to the International NB Staging System.13 Age, sex, primary tumor site, Shimada classification of pathology,14 surgical complications, and the patients outcome were also recorded.
All patients underwent an initial diagnostic biopsy. Surgical specimens were submitted to pathologic assessment as well as to analysis of molecular markers, including Trk-A expression and MYCN status, before chemotherapy. After biopsy, all patients received induction chemotherapy that consisted of cisplatin 60 mg/m2 day 1, VP-16 100 mg/m2 and epirubicin 30 mg/m2 day 2, cyclophosphamide 900 mg/m2 days 3 and 4, and VP-16 60 mg/m2 day 5. Each cycle was repeated every 4 weeks. GTR of the tumor was attempted after three to six cycles of chemotherapy. GTR was defined as removal of the macroscopic primary tumor and all regional lymph nodes, according to the operation record. There should be no grossly visible tumors detected by the immediate follow-up magnetic resonance imaging or computed tomographic scan studies 10 days after the definitive operation. A second-look operation might be needed to achieve GTR after initial partial resection and a subsequent additional chemotherapy response. Patients who underwent lesser procedures (partial excision and biopsy) were grouped as incomplete resection (IR) for comparison with the GTR group. After the definitive surgical procedure, patients received three to five cycles of maintenance chemotherapy (repeated induction regimen) or autologous bone marrow transplantation. The median follow-up after the diagnosis was 30 months (range, 5144 months).
Assessment of Trk-A Expression by Immunohistochemistry
The details of immunostaining for the Trk-A gene product have been described previously.15 Trk-A expression was examined on sections from formalin-fixed, paraffin-embedded tissue by an avidin-biotin complex immunoperoxidase staining technique. A rabbit anti-human Trk-A antibody (Upstate Biotechnology Inc., Lake Placid, NY) at a dilution of 1/150 was used as a primary antibody. Diaminobenzidine was used for visualization, and nuclei were counterstained with hematoxylin. One ganglioneuroma tumor with consistent Trk-A expression by immunohistochemistry was used as a positive control. Nonimmunized rabbit serum was used as a negative control. The immunoreactivity of Trk-A was recorded as follows: "negative" indicated that staining was absent throughout the specimen, and "positive" indicated that brownish granular staining was present in the cytoplasm of the NB or ganglion cells.
Analysis of MYCN Amplification by Fluorescence In Situ Hybridization
The MYCN status in NB tumors was evaluated by fluorescence in situ hybridization (FISH) analysis of formalin-fixed paraffin-embedded tissues or fresh single tumor cells.16,17 The nuclei on slides were denatured in 70% formamide/2x standard saline citrate and rehydrated. The MYCN gene probe (spectrum orange) and the internal control TelVysion 2p probe (spectrum green), acquired from Vysis (Downers Grove, IL), were used for hybridization. Metaphase spreads were counterstained with .5 mg/mL of 4',6-diamidino-2-phenylindole in Vectashield (Vector, Burlingame, CA). Fluorescent signals representing the presence of the MYCN gene were counted for 100 cells on each slide. Cells with clusters or more than six grains of red fluorescence were considered evidence of MYCN gene amplification.17 Lymphocytes obtained from a healthy male donor were used as controls for the FISH study.
Risk Grouping
To further evaluate the influence of biological factors on the role of surgery in the prognosis of NB, the prognosis of all patients was classified into three risk groups according to the two biological markers of Trk-A and MYCN: low risk (positive Trk-A expression and normal MYCN copy number), intermediate risk (negative Trk-A expression and normal MYCN copy number), and high risk (MYCN amplification with positive or negative Trk-A expression).
Statistical Analysis
The statistical analyses were performed with SPSS 10.0 software for Windows (SPSS Inc., Chicago, IL). Associations between pairs of categorical variables were assessed with Pearsons
2 test. Survival probabilities in various subgroups were estimated with the Kaplan-Meier method. Survival of groups was compared by log-rank tests. All statistical tests were two sided, and a P value of
.05 was considered to be statistically significant.
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RESULTS
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There were 27 men and 18 women. The median age at diagnosis was 3.5 years (range, .511.5 years); 4 were
1 year of age, and 41 were older than 1 year. The patphology was favorable in 17 tumors and unfavorable in 28 according to Shimadas classification. In 26 patients, the primary tumors were located in the adrenal gland; 9 were paraspinal, 5 mediastinal, 3 cervical, and 2 pelvic. After induction chemotherapy, GTR was achieved in 21 patients. Among 24 patients with incomplete tumor excision, 5 patients did not receive further tumor excision except for biopsy because they died from rapid tumor progression or chemotherapy complications. In the GTR group, there was no surgical mortality, but there was 1 chylothorax and there were 2 cases of adhesion ileus and 4 nephrectomies, for a total complication rate of 33% (7 of 21). The nephrectomies were necessitated by direct involvement of tumor with the renal parenchyma or vessels. In the IR group, there was 1 mortality (respiratory failure after biopsy of the mediastinal tumor) and 1 nephrectomy, for a total complication rate of 8% (2 of 24). The complication rate was significantly higher in the GTR group (P = .036).
Fifteen (33.3%) tumors had a variable percentage (12%93%) of cells with positive signals of fluorescence of MYCN in FISH analysis and were recognized as having MYCN amplification (Fig. 1A and B
). Seventeen (37.8%) tumors had positive Trk-A immunostaining on NB or ganglion cells (Fig. 1C and D
).
GTR is a serious and often life-threatening operation. However, in this study of a small patient population, GTR carried prognostic benefit in only a selected intermediate-risk biological group of NB patients. GTR did not show a beneficial effect in NB patients with high biological risk tumors because of the overall poor prognosis of these patients. For NB patients of low biological risk, it was difficult to analyze the effect of different surgical procedures on their prognosis because of the overall favorable outcome and the high GTR rate in these patients. Further studies with large patient populations are needed to clarify the influence of biological factors on surgical strategies for advanced NB.
Received for publication October 15, 2004.
Accepted for publication August 24, 2005.