Radiotherapy or chemotherapy for clinical stage IIA and IIB seminoma: a systematic review and meta-analysis of patient outcomes

Background: Outcomes of radiotherapy (RT) compared with chemotherapy (CT) remain poorly defined for clinical stage (CS) IIA and IIB seminoma. We aimed to evaluate the current role of the two treatment modalities in this setting of testicular seminoma.

Patients and methods: A systematic review and meta-analysis (MA) was carried out to identify all evaluable studies. Search was limited to studies published after 1990 and included the Medline, Embase databases, and abstracts from ASCO (GU), ESMO, AUA, and ASTRO meetings up to April 2014. Sensitivity analyses were applied including the following: CSIIA and CSIIB, paraortic + iliac RT only in both stages, RT dose (≥30 versus <30 Gy), and PEB/EP regimens only.

Results: Thirteen studies have been selected for MA on relapse outcome. No randomized trials compared RT and CT. There were 4 prospective and 9 retrospective studies, with a total of 607 patients receiving RT and 283 patients CT. The pooled relapse rate (RR) was similar between the RT [0.11, 95% confidence interval (CI) 0.08-0.14, P for heterogeneity = 0.096, I(2) = 38%] and CT groups (0.08, 95% CI 0.01-0.15, P for heterogeneity <0.001, I(2) = 82.5%). However, in the sensitivity analysis, the pooled RR for RT in CSIIB was 0.12 (95% CI 0.06-0.17) while it was 0.05 (95% CI 0-0.11) for CT. Long-term side-effects and incidence of second cancers were more frequently reported following RT. The overall incidence of nontesticular second malignancies was 0.04 (95% CI 0.01-0.02) in the RT group and 0.02 (95% CI 0.003-0.04) in the CT group.

Conclusions: Although RT and CT appeared to be equal options in CSIIA and IIB seminoma, a trend in favor of CT for a lower incidence of side-effects and RR in CSIIB was found. This evidence is limited by the retrospective quality of studies and their small sample size.