Role of Postoperative Radiotherapy in the Management of Merkel Cell Carcinoma

Abstract

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor of the skin with a high potential of locoregional relapse after surgery alone. This report is an update of our experience in the treatment of MCC. From January 1990 to May 2000, 31 patients with MCC, 13 men and 18 women aged between 34 and 92 years, were treated at the University of Cologne, Germany. Primary tumor sites were in the head and neck region in 13 patients, limbs in 13, and trunk in 5. The tumors were stage I in 26 of 31 patients, stage II in 4 of 31 and stage III in 1 of 31. Treatment included surgery alone in 14 of 31 patients, adjuvant postoperative radiotherapy in 16 of 31 patients, 1 of them had incomplete surgery, and definitive radiotherapy in 1 of 31 patients (stage III). Median overall survival (OS) after first diagnosis was 32 months (95% confidence interval: 0-75 months) with a 3-year OS rate of 47% (95% CI: 25-69%). Six of 31 patients relapsed locally after a median of 4 months, 10 of 31 patients developed regional node metastases, and 7 of 31 patients distant metastases. Nine patients died as a direct result of MCC. Locoregional control and disease-free survival were significantly improved in the group with postoperative radiotherapy (p = 0.023). Uni- and multivariate analysis revealed that head and neck location of the tumor and the lack of postoperative radiotherapy are unfavorable prognostic factors. Postoperative radiotherapy to the primary tumor region and the regional lymphatics is effective in the prevention of locoregional recurrence. Prospective clinical trials should be performed to confirm these observations.

Human Merkel cell polyomavirus: virological background and clinical implications

“…Positive diagnosis of MCC is based on immunohistochemistry, as MCC expresses both neuroendocrine and epithelial markers. MCC tumor cells display paranuclear dot-like staining with cytokeratin 20 and absence of staining with cytokeratin 7 (CK20+/CK7À), (65,66,86) although very rare variants with CK20À/CK7+ expression have been reported (96). Positive staining with a neuroendocrine marker (synaptophysin or chromogranin A) is therefore a clue for diagnosis.…”

Merkel Cell Carcinoma of the Skin: A Retrospective Study of 24 Cases by the Hellenic Cooperative Oncology Group

“…The majority of published studies support the use of adjuvant RT after complete resection of the tumor [9, 12,19,20,21,22]. Most of these studies showed a reduction in local relapse rate, with 0–33% for patients treated with adjuvant RT and 21–89% for patients treated only with surgery [4, 9,23,24,25,26,27]. In addition, some studies showed a reduction in regional recurrence rate from 50–94 to 19–27% with the use of adjuvant RT [9, 23, 24, 26].…”

“…Most of these studies showed a reduction in local relapse rate, with 0–33% for patients treated with adjuvant RT and 21–89% for patients treated only with surgery [4, 9,23,24,25,26,27]. In addition, some studies showed a reduction in regional recurrence rate from 50–94 to 19–27% with the use of adjuvant RT [9, 23, 24, 26]. The DFS reported in the literature was 4–9 months for patients treated only with surgery and 4.9–32 months for those treated with the addition of adjuvant RT [9, 20, 21, 23, 28, 29].…”

“…In addition, some studies showed a reduction in regional recurrence rate from 50–94 to 19–27% with the use of adjuvant RT [9, 23, 24, 26]. The DFS reported in the literature was 4–9 months for patients treated only with surgery and 4.9–32 months for those treated with the addition of adjuvant RT [9, 20, 21, 23, 28, 29]. Muller et al [23] also showed a better relapse-free survival with the addition of adjuvant RT in patients with stage I disease.…”

“…The DFS reported in the literature was 4–9 months for patients treated only with surgery and 4.9–32 months for those treated with the addition of adjuvant RT [9, 20, 21, 23, 28, 29]. Muller et al [23] also showed a better relapse-free survival with the addition of adjuvant RT in patients with stage I disease. Although most of the literature results showed a reduction only in local and/or regional recurrence rate, Kokoska et al [27] reported an improvement in distant relapse rate from 65 to 23% (p = 0.02) and in overall 2-year survival from 40 to 77% with the use of adjuvant RT.…”