A meta-analysis of patient outcomes with subcentimeter disease after chemotherapy for metastatic non-seminomatous germ cell tumor

Abstract

Approximately a quarter of men with metastatic non-seminomatous germ cell tumor (NSGCT) have a residual mass, typically in the retroperitoneum, after chemotherapy. The management of small residual masses (≤1 cm) is controversial, with good outcomes seen with either post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) or surveillance. We sought to review our experience of surveillance and synthesize the cumulative findings with the current literature in the form of a meta-analysis. We searched PubMed, EMBASE and abstracts from ASCO and AUA to identify relevant, English-language studies for the meta-analysis. The DFCI (Dana Farber Cancer Institute) database was constructed from a database of men undergoing cisplatin-based chemotherapy for metastatic NSGCT. The outcomes of interest were the proportion with necrosis, teratoma or active cancer on histology at PC-RPLND (literature) and the total number of relapses, RP-only relapses and overall survival in men undergoing surveillance (literature and DFCI cohort). Three of 47 men undergoing post-chemotherapy surveillance at our institution relapsed over a median follow-up of 5.4 years. All three were alive at a median of 4.2 years after relapse. On meta-analysis, the pooled estimates of necrosis, teratoma and active cancer in the 588 men who underwent PC-RPLND were 71, 24 and 4%, respectively. Of the combined 455 men who underwent surveillance, the pooled estimate of the relapse rate was 5%, with an RP-only relapse rate of 3%. Of the 15 men who suffered an RP-only relapse on surveillance, two died of disease. Surveillance is a reasonable strategy for men with minimal residual RP disease after chemotherapy and avoids an RPLND in ∼97% of men who are cured with chemotherapy alone.