[Management of Merkel cell carcinoma: Role of radiotherapy in elderly patients].

PURPOSE

Merkel cell carcinoma carcinoma (MCC) or primary cutaneous neuroendocrine carcinoma is a rare and aggressive malignancy affecting elderly. Optimal therapeutic strategy has not yet been established in elderly patients.

PATIENTS AND METHODS

From March 1996 to March 2007, 29 patients with Merkel cell carcinoma of were treated at the University Hospital of Amiens, France. Adjuvant radiotherapy (RT) was performed for 14 patients (50%) on the tumor bed with margins of 3 to 5cm, an average dose of 46Gy (30-60Gy), by 2Gy per fraction. Ten of them also received RT to the lymph node area at mean dose of 44.3Gy (26-50Gy). Duration of RT was 35 days. A retrospective analysis was conducted to better evaluate survival and prognostic factors.

RESULTS

Median overall survival (OS) was 18.9 months (3-122) and the median time to progression (MTP) 5.5 months (1-26). At 5 years, OS for irradiated patients was 47% (IC95: 12-82%) versus 27% (IC95: 5-49%) in cases of surgery alone (p=0.032). The most frequent sites of recurrence were nodal (34.5%), local (24.1%) and metastatic (17.2%). For patients over 70 years, eight (36.5%) were free of disease at last news, 8 (36.5%) had died from cancer and six from other causes (27%). In this subgroup, MTP was 6 months (2-19) and median OS of 19 months (4-87). There was no acute toxicity greater than grade 2.

CONCLUSION

Although limited by a retrospective analysis, this report suggests an advantage of postoperative RT for patients with MCC. It combined low toxicity and improvement of survival. Prospective multicenter trials are needed to clarify and validate the optimal strategy.