Largest study of patients with early stage II testicular cancer shows radiation therapy is more effective than chemotherapy
A large study of testicular cancer patients has shown that radiation therapy is a better treatment than chemotherapy for patients with stage IIa disease (where one or more regional lymph nodes contain cancer cells but they are less than 2cms in diameter).
These findings, presented at the ESTRO 35 conference and published simultaneously in Clinical Oncology, are important because, until now, there has been little evidence about which treatment for testicular seminoma is more effective, and there has been a tendency to move away from radiation therapy towards chemotherapy for treating stage IIa-b patients. Guidelines from the US National Cancer Comprehensive Network recommend radiotherapy for stage IIa, while those from the European Association of Urology allow for either radiation therapy or chemotherapy; both sets of guidelines are equivocal for stage IIb.
The study of 2,437 patients presented today is the largest group of patients with stage II testicular seminoma evaluated so far, and researchers found that 99% of patients with IIa disease were alive after five years if they had been treated with radiation therapy, versus 93% of patients treated with chemotherapy. For patients with IIb disease, the five-year overall survival was 95% for those treated with radiation therapy and 92% for those treated with chemotherapy.
Dr Scott Glaser, resident physician at the University of Pittsburgh Cancer Institute, USA, told the conference: “For patients with IIa testicular seminoma, this improvement in outcome with radiation over chemotherapy persisted after adjustments for all available factors that could introduce a bias. For patients with stage IIb disease, similar rates of overall survival were seen regardless of treatment with multi-agent chemotherapy or radiation therapy. This suggests that an individualised approach is necessary for such patients.”
He continued: “Testicular seminoma is a rare disease, there is a lack of randomised data to guide treatment and many prior studies have been limited by small sample sizes. It has, therefore, been difficult to tease out small differences in efficacy of radiation therapy versus chemotherapy. The trend away from radiation therapy may be due to a misperception that it is more toxic than three or four cycles of multi-agent chemotherapy. Across this large, national dataset, radiation therapy was associated with a better outcome for stage IIa patients and equivalent outcomes for stage IIb patients. However, potential explanations for these improved outcomes are less clear.”