ORLANDOA German university study contradicts the belief commonly held by many clinical researchers that malignant melanoma is not sensitive to radiation therapy. Dr. M. Heinrich Seegenschmiedt, of the University of Erlangen-Nurnberg, presented the findings at the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO).
Of 2,917 consecutive patients with locally advanced, recurrent, or metastatic malignant melanoma treated between 1977 and 1995, 121 (4%) were selected to receive external beam radiation as palliative therapy for advanced-stage disease (UICC stages II to IV). In most cases, radiation was regarded as a last resort treatment after other therapies had failed or proved insufficient.
Eleven patients had residual disease after resection of a primary or recurrent malignant melanoma (stage II); 57 had regional lymph node metastases or in-transit metastases (stage III); and 53 had distant metastases (stage IV).
The median length of time from initial diagnosis to application of radiation therapy was 19 months. Most patients received conventional radiation therapy, although in a few cases, hypofractional radiation was applied. Median follow-up was 9 years.
Disease stage significantly predicted outcome. At 3 months follow-up, all 11 of the stage II patients had achieved an objective clinical response, and 7 had a complete response. Of the 57 stage III patients, 44 had an objective response, including 25 complete responses. In the 53 stage IV patients, 26 responded, and 9 had a complete response.
Tumor progression was observed in 21% of the patients during radiation therapy. Those patients who had a complete response lived a median 40 months longer than those who did not. In 1995 at the last follow-up, 26 patients were still alive6 with stage II disease, 17 with stage III, and 3 with stage IV (see Figure).
Dr. Seegenschmiedt said that the absence of major side effects in this study, along with the clinical responses, shows that radiation therapy for advanced melanoma, even metastatic stage III and IV disease, can improve patients quality of life. He also noted that radiation is less expensive than chemotherapy and does not have the accompanying side effects. Combination treatment could prove beneficial in poor-prognosis patients, he added, and should be further studied in randomized trials.