Postoperative radiotherapy in head and neck mucosal melanoma: a GETTEC study.

OBJECTIVE

to report patterns of failure according to treatment modality, with an emphasis on the role of postoperative radiotherapy in patients with localized head and neck mucosal melanoma (HNMM) treated during a 28-year period in a multi-institutional setting.

DESIGN

retrospective review.

SETTING

french medical institutions.

PATIENTS

a total of 160 patients with nonmetastatic HNMM treated from 1980 through 2008.

INTERVENTIONS

treatment modality consisted of surgery alone (hereinafter, S group) (n = 82 patients) or with postoperative radiotherapy (hereinafter, SRT group) (n = 78). Patients and tumor characteristics were similar in the 2 groups. There was a nonsignificant trend (P = .11) for more locally advanced tumor stage (38.9%) in the SRT group compared with the S group (24.5%).

RESULTS

patients in the S group had an increased probability of locoregional recurrence as a first event (55.6%) compared with those in the SRT group (29.9%; P < .01). After adjusting for tumor stage (T1/T2 vs T3/T4), the subdistribution hazard ratio of locoregional relapse was 0.31, (95% confidence interval [CI], 0.15-0.61; P < .01).The rate of distant metastasis as a first event was significantly higher in the SRT group (40.6%) compared with the S group (19.9%; P = .01). Regardless of their treatment, patients who had a locoregional relapse during follow-up had an increased risk of subsequent distant metastasis (hazard ratio, 3.07; 95% CI, 1.65-5.67) and death (hazard ratio, 3.01; 95% CI, 1.91-4.78).

CONCLUSIONS

this large retrospective study suggests that postoperative radiotherapy improves the locoregional control of HNMM. The higher rate of distant metastasis was due to more advanced disease in the SRT group.