Patients with stage IIA testicular cancer gain a survival advantage from treatment with radiation therapy compared with chemotherapy, according to a study presented at ESTRO 35, the 2016 annual meeting of the European Society for Radiotherapy and Oncology, and simultaneously published online ahead of print in Clinical Oncology.1,2
Previously, little evidence existed to determine which treatment for testicular seminoma is more effective. Although US guidelines from the National Comprehensive Cancer Network recommend radiotherapy for stage IIa disease, European Association of Urology guidelines allow for either radiation therapy or chemotherapy; both sets of guidelines are equivocal for stage IIb.
This retrospective study included 2437 patients, making it the largest group of patients with stage II testicular seminoma evaluated so far. The study used the US National Cancer Database and had an average follow-up of 65 months.
After 5 years, 99% of patients with stage IIa disease were alive if they were treated with radiation therapy vs 93% of patients treated with chemotherapy. For patients with stage IIb disease, the 5-year overall survival was 95% for those treated with radiation therapy and 92% for those treated with chemotherapy.
“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 individualized approach is necessary for such patients,” said Scott Glaser, MD, resident physician at the University of Pittsburgh Cancer Institute in Pennsylvania.
Glaser explained that because testicular seminoma is a rare disease, randomized data to guide treatment decisions is lacking and prior studies have been limited by small samples sizes. Treatments have been trending away from radiation therapy because of greater perceived toxicity compared with 3 to 4 rounds of multi-agent chemotherapy. However, radiation therapy led to better outcomes for stage IIa patients and equivalent outcomes for stage IIb patients.
“We view stage IIb disease as a spectrum where smaller volume disease patients (ie, those with a 2-3 cm tumor in a single lymph node) may act more like IIa disease and attain the greatest benefit from radiation therapy, whereas patients with a larger volume of disease (ie, 4-5 cm tumor or metastasis to multiple lymph nodes) may act more like IIc disease and attain the greatest benefit from chemotherapy,” said Glaser.
1. Glaser SM, Balasubramani GK, Beriwal S. Stage II testicular seminoma: patterns of care and survival by treatment strategy. Presentation at: ESTRO 35; April 29-May 3, 2016; Turin, Italy. Abstract OC-0539.
2. Glaser SM, Vargo JA, Balasubramani GK, Beriwal S. Stage II testicular seminoma: patterns of care and survival by treatment strategy [published online ahead of print March 13, 2016]. Clin Oncol. doi:10.1016/j.clon.2016.02.008.