Purpose: Radiotherapy (RT) is used as last resort for patients with advanced cutaneous malignant melanoma (MM). Herein our 20-year clinical experience is presented analyzing different endpoints and prognostic factors in patients with locally advanced, recurrent or metastatic MM.
Patients and methods: From 1977 to 1995, 2,917 consecutive patients were entered in the MM registry of our university hospital. RT was indicated in 121 patients (56 females, 65 males) for palliation in locally advanced recurrent and metastatic MM stages UICC IIB to IV. At the time of RT initiation, 11 patients had primary or recurrent lesions which were either not eligible for surgery or had residual disease (R2) after resection of a primary or recurrent MM lesion (UICC IIB); 57 patients had lymph node (n = 33) or in-transit metastases (n = 24) (UICC III), and 53 had distant organ metastases (7 M1a, 46 M1b) (UICC IV). The time from first diagnosis to on-study RT averaged overall 19 months (median: 18; range: 3 to 186 months). In 77 patients conventional RT and in 44 patients hypofractionted RT was applied with 2 to 6 Gy fractions up to a mean total RT dose of 45 (median: 48; range: 20 to 66) Gy.
Results: At 3 months follow-up, complete response (CR) was achieved in 7 (64%), overall response (CR + PR) in all (100%) UICC IIB patients, in 25 (44%) and 44 (77%) of 57 UICC III patients, and in 9 (17%) and 26 (49%) of 53 UICC IV patients. Tumor progression during RT occurred in 25 (21%) patients. Patients with CR survived longer (median: 40 months) than those without CR (median 10 months) (p < 0.01). At the time of evaluation and last FU (December 31, 1996), 26 patients were still alive: 6 (55%) stage UICC IIB, 17 (30%) stage UICC III, and 3 (6%) stage UICC IV patients (p < 0.01). Univariate analysis revealed following prognostic factors for CR and long-term survival: UICC stage (p < 0.001), primary location in the head and neck, total RT dose > 40 Gy (all p < 0.05), while age, gender and primary histological subtype had no impact. In multivariate analysis, UICC stage was the only independent favorable prognostic factor for achievement of CR and long-term survival (p < 0.001).
Conclusion: External RT provides effective palliation in advanced UICC stages. The UICC staging system is a good predictor of initial and long-term tumor response in metastatic MM. Prospective randomized trials using RT with or without adjuvant therapy for advanced MM are justified.