Percentage tumor necrosis following chemotherapy in neuroblastoma correlates with MYCN status but not survival.

The percentage of chemotherapy-induced necrosis in primary tumors corresponds with outcome in several childhood malignancies, including high-risk metastatic diseases. In this retrospective pilot study, the authors assessed the importance of postchemotherapy necrosis in high-risk neuroblastoma with a histological and case notes review of surgically resected specimens. The authors reviewed all available histology of 31 high-risk neuroblastoma cases treated with COJEC (dose intensive etoposide and vincristine with either cyclophosphamide, cisplatin or carboplatin) or OPEC/OJEC (etoposide, vincristine and cyclophosphamide with alternating cisplatin [OPEC] or carboplatin [OJEC]) induction chemotherapy in 2 Children's Cancer & Leukaemia Group (CCLG) pediatric oncology centers. The percentage of postchemotherapy necrosis was assessed and compared with MYCN amplification status and overall survival. The median percentage of postchemotherapy tumor necrosis was 60%. MYCN status was available for 28 cases, of which 12 were amplified (43%). Survival in cases with ≥ 60% necrosis or ≥ 90% necrosis was not better than those with less necrosis, nor was percentage necrosis associated with survival using Cox regression. However, MYCN-amplified tumors showed a higher percentage of necrosis than non-MYCN-amplified tumors, 71.3% versus 37.2% (P = .006). This effect was not related to prechemotherapy necrosis and did not confer improved overall survival. Postchemotherapy tumor necrosis is higher in patients with MYCN amplification. In this study, postchemotherapy necrosis did not correlate with overall survival and should not lead to modification of postoperative treatment. However, these findings need to be confirmed in a larger prospective study of children with high-risk neuroblastoma.