Although Merkel cell carcinoma is a rare neuroendocrine carcinoma of the skin, the disease may share etiological factors with other tumor types, making patients vulnerable to a second cancer, according to a study out of Finland.
"MCCs and some other skin cancers, such as basal cell carcinomas, frequently harbor Merkel cell polyomavirus DNA," explained the investigators from the department of plastic surgery at Helsinki University Central Hospital.
The risk for second cancer "may in part result from shared etiological factors between MCC and other tumor types such as immunosuppression or possibly Merkel cell polyomavirus infection," they wrote (Cancer Epidemiol online, January 8, 2010).
The authors looked at the incidence of second primary cancers after the diagnosis of MCC from the files of the Finnish Cancer Registry from 1979 to 2006. Among the 172 MCC patients identified, 34 second primary cancers were detected in 30 individuals after the diagnosis of MCC.
Female MCC patients were diagnosed with 25 subsequent cancers (standardized incidence ratio [SIR] of 2.35;
P < .001) and male MCC patients were diagnosed with nine cancers (SIR of 2.32; P < .05). The MCC patients had an increased risk for a subsequent cancer at any site compared to a general population matched by age, gender, and calendar period (SIR of 2.34).
The authors also found that the risks for basal cell carcinoma of the skin (SIR of 3.48) and chronic lymphocytic leukemia (SIR of 17.9) were significantly elevated. However, the SIRs for an overall second primary cancer risk did not change markedly with time since the diagnosis of Merkel cell carcinoma, the authors pointed out.
In a letter to the Archives of Surgery (145:104-105, 2010), surgical oncologists from France described a case of a 66-year-old woman with a painless but growing right axillary mass. Mammography and thoracoabdominal CT did not find pathologic features, but an open biopsy led to the diagnosis of MCC. A skin and mucosal examination by a dermatologist confirmed the absence of any other lesion, reported Claire Chalumeau, MD, and Pablo Ortega-Deballon, MD, PhD, of Centre Hospitalier Universitaire du Bocage in Dijon.
The large mass, involving the right axillary vein and the pectoralis and latissimus dorsi muscles, was excised. Coadjuvant radiotherapy and chemotherapy (three cycles with cisplatin and etoposide phosphate) were given. At five years, the patient remains healthy with no evidence of recurrent disease or skin lesions.
"We think that an aggressive, multimodal approach is warranted in these patients," they stated.