The first randomized trial to evaluate the long-term outcome of treatment with a single dose of chemotherapy for early-stage testicular tumors has found that the approach is safe, effective, and less toxic compared to radiation therapy, the current standard of care. The study, the largest ever in testicular cancer, also showed that after 5 years, patients receiving chemotherapy had a decreased risk of developing a second tumor in the other testicle, though longer follow-up is needed. The data were presented by R.T. Oliver, md, professor emeritus of medical oncology at St. Bartholomew’s Hospital in London and the study’s lead author, at the ASCO plenary session (abstract 1).
All patients in the study had seminoma, which makes up about half of all testicular cancers, and were first treated with surgery to remove the affected testicle. Patients were randomized to receive either a single dose of the chemotherapy drug carboplatin given over 1 hour on an outpatient basis (573 patients) or a course of daily radiation therapy given for 2 or 3 weeks (904 patients). The dose of carboplatin varied and was based on each patient’s kidney function. After 5 years, the rate of cancer recurrence was comparable in both arms—5% of patients in the chemotherapy group and 4% of patients in the radiation therapy group.
With a median follow-up of 6.5 years, patients who received carboplatin were 78% less likely to develop a tumor in the remaining testicle (15 patients in the radiation therapy arm vs 2 in the carboplatin arm). One patient in the radiotherapy arm died of seminoma, vs none in the chemotherapy arm. Side effect rates for both treatments were low, although those in the radiation therapy group reported higher levels of moderate or severe lethargy (24% vs 7% for patients receiving carboplatin) 4 weeks after starting treatment.
“Personal preference is becoming a more important factor in determining the best treatment for patients with testicular cancer. We’ve also seen this in prostate cancer, where there are a number of equally strong treatment options,” said Dr. Oliver. “This study establishes surgery followed by carboplatin chemotherapy as a safe new alternative for patients who have early-stage seminoma and would prefer a treatment that lasts a shorter period of time.”
The researchers said that future studies will investigate the option of lumpectomy and single-dose carboplatin for men who present early enough with small tumors, allowing them to avoid losing the diseased testicle.