Background: In high-risk neuroblastoma patients, response to induction chemotherapy is emerging as an important determinant of overall survival. We sought to determine whether histological changes in the primary tumor following induction therapy could be used as a marker of response.
Procedure: Second-look primary tumor specimens from 43 patients were reviewed according to specific morphological features.
Results: In the majority, induction therapy resulted in a shift from an intermediate/high to low mitosis-karyorrhexis index (MKI) (P = 0.0009) and from undifferentiated/poorly differentiated to differentiating tumors (P < 0.0001). Following induction therapy, persistence of intermediate/high tumor MKI and ≥90% persistent neuroblastic cells were predictive of a poor outcome (P = 0.001 and 0.03, respectively). Less than 10% tumor necrosis was associated with a trend towards lower survival.
Conclusions: High proliferative activity in the primary tumor following induction therapy portends a poor outcome in patients with high-risk neuroblastoma. If confirmed in a larger cohort, tumor histology at second-look surgery could be used to define a subset of very high risk patients who would benefit from alternative therapies prior to myeloablative dose-intensive transplant.
Copyright © 2011 Wiley Periodicals, Inc.