Merkel Cell Carcinoma is a rare and aggressive neuroendocrine malignancy of the skin.
This study seeks to determine the prognostic value of adjuvant radiation therapy in
relation to disease-free survival among patients treated surgically for Merkel Cell
Carcinoma.
-The methods and materials used:
The Vanderbilt Melanoma and Cutaneous Malignancy Data Repository was searched for
patients treated for Merkel Cell Carcinoma. Data was collected regarding demographics
medical comorbidities, tumor stage, and treatment for patients diagnosed with Merkel
Cell Carcinoma from 1998 to 2010.
-Experience including number of cases and follow-up:
A total of 27 cases were identified. The mean follow-up period was 32.9 months (range,
1-143 months). No statistical difference was observed regarding follow-up between
patients receiving adjuvant radiation and those receiving excision only (p = 0.37). Mean
follow-up for stage I patients who received adjuvant radiation was 29.1 months, and 22.4
months for those who received no radiation (p = 1.0).
-Summary of results:
The average age of the population was 70.8 years. Of those receiving adjuvant
radiation, the mean age was 66.1 years, compared to 74.6 years for those not receiving
radiation (p = 0.08). All patients received wide-local excision. Of the 27 patients, 3 were
diagnosed with metastatic disease and excluded from comparison. 10 patients received
adjuvant radiation therapy, of which 40% were stage I, 10% stage II, and 50% were
stage III. The remaining 14 patients received excision only. Of these, 78.5%
were stage I, while 21.5% were stage III. No recurrence was observed among the 4
patients receiving radiation therapy for stage I disease. However, of the 11 stage I
patients not receiving radiation therapy 4 recurred (36.3%).
-Reasonable and understandable conclusions:
These results suggest that stage I Merkel Cell Carcinoma should be treated with
wide-local excision and adjuvant radiation therapy. Given the small sample size
further studies are needed to validate this conclusion, however, our data suggests
that early stage Merkel Cell should be treated with XRT to reduce rate of recurrence.