After surgery, a single dose of carboplatin appears to be just as effective in preventing relapse as three weeks of radiation therapy in men with early-stage Testicular cancer, according to the findings of a study published in this week’s issue of The Lancet. Carboplatin also appears to be associated with less severe adverse effects and lower risk of developing a tumor in the other testicle.

Although radiotherapy has long been the accepted treatment approach, research has suggested that it may increase the risk of later developing other types of cancer and cardiovascular disease. Based on preliminary study findings that found one course of carboplatin is as effective as radiation, Dr. R. T. D. Oliver and colleagues initiated a trial comparing the two strategies.

Oliver, from St. Bart’s and the London Hospital in the UK, and colleagues included 1,477 patients with stage I Testicular cancer from 70 hospitals in 14 countries treated between 1996 and 2001. The analysis included 885 men randomly assigned to radiotherapy and 560 to carboplatin. The subjects were followed for an average of four years.

The relapse-free rate at three years was 95.9 percent in the radiation group and 94.8 percent in the carboplatin group, a nonsignificant difference. New, second primary testicular germ-cell tumors developed in 10 patients treated with radiation and two treated with carboplatin. One testicular cancer-related death occurred in the radiation group.

There were no significant differences at two years in gonadal function as measured by hormone levels. Although adverse events were more common at 72 hours in the carboplatin group, carboplatin was associated with less lethargy over the next few of months and a more rapid return to work.

“This trial has shown the non-inferiority of carboplatin to radiotherapy in the treatment of stage I seminoma,” the authors conclude. They add, “These findings need to be confirmed beyond four years’ follow-up.”

In a related commentary, Drs. Padraig Warde and Mary Gospodarowicz, from the University of Toronto, caution against adopting carboplatin as standard follow-up treatment after surgery for early-stage Testicular cancer because surveillance alone seems to be a safe option.

However, they add, “We do agree with Oliver and colleagues that adjuvant carboplatin is worthy of continued study and might be of benefit in some settings.”

SOURCE: The Lancet, July 23, 2005.