A pilot study by researchers at the Institute of Cancer Research and the Royal Marsden NHS Foundation Trust found that early carboplatin treatment reduced the risk of patients needing later combination chemotherapy.
An early chemotherapy dose also made it possible to provide effective radiotherapy with less radiation delivered to a smaller body area.
Combination chemotherapy can have serious long-term side-effects including heart disease and secondary cancers.
In the study, 51 men with stage IIA and IIB testicular seminoma (where the cancer has spread to abdominal lymph nodes) a single cycle of carboplatin, followed three to four weeks later by radiotherapy.
The chemotherapy enabled doctors to give 39 of the patients a 15% lower dose of radiation, applied to a smaller area of the abdomen.
After an average of 4.5 years, there were no relapses of the cancer in these patients, compared with a relapse rate of 5–11% after radiotherapy alone.
Dr Robert Huddart, Team Leader in the Division of Radiation and Imaging at the Institute of Cancer Research, London, said: “The aim of the study was to develop an effective non-toxic treatment with low risk of long-term treatment complications.
“Our findings suggest that a single cycle of carboplatin before radiotherapy may reduce the chances of cancer reappearing compared with radiotherapy alone. This will reduce the risk that these patients would need combination chemotherapy.
“Not only that, but by adding carboplatin to the therapy, the radiation dose and volume can be lowered.”