Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin cancer with a disease-specific mortality of approximately 40 %. The association of MCC with a recently discovered polyomavirus, combined with the increased incidence and mortality of MCC among immunocompromised patients, highlight the importance of the immune system in controlling this cancer. Initial management of MCC is summarized within the NCCN guidelines and in recently published reviews. The high rate of recurrent and metastatic disease progression in MCC, however, presents a major challenge in a cancer that lacks mechanism-based, disease-specific therapies. Traditional treatment approaches have focused on cytotoxic chemotherapy that, despite frequent initial efficacy, rarely provides durable responses and has high morbidity among the elderly. In addition, the immunosuppressive nature of chemotherapy is of concern when treating a virus-associated cancer for which survival is unusually tightly linked to immune function. With a median survival of 9.6 months after development of an initial metastasis (n = 179, described herein), and no FDA-approved agents for this cancer, there is an urgent need for more effective treatments. We review diverse management options for patients with advanced MCC, with a focus on emerging and mechanism-based therapies, some of which specifically target persistently expressed viral antigens. These treatments include single-dose radiation and novel immunotherapies, some of which are in clinical trials. Due to their encouraging efficacy, low toxicity, and lack of immune suppression, these therapies may offer viable alternatives to traditional cytotoxic chemotherapy.
Merkel cell carcinoma can be indolent: A case with 7 locoregional recurrences over 15 years highlights the importance of patient-tailored management
Patients who experience a recurrence of their Merkel cell carcinoma are often treated aggressively. We report a case of a man with an unusually long course of MCC over 15 years who had his MCC recur around his face or neck 7 times before eventually developing distant spread. Because he had 4 major medical problems at the time his MCC initially appeared, less aggressive therapies were chosen for his recurrences, and there was no evidence of disease for the vast majority of his 15-year course, during which he enjoyed excellent quality of life. This case emphasizes the importance of customizing care in MCC to give patients the best quality and quantity of life possible in their particular situation.