Complete spontaneous regression of merkel cell carcinoma.

I read the article "Complete spontaneous regression of Merkel cell carcinoma metastatic to the liver: Did lifestyle modifications and dietary supplements play a role?"(1) with great interest. Merkel cell carcinoma carries a significant rate of recurrence and mortality.(2) Though spontaneous regression of Merkel cell carcinoma has been well documented in the literature,(3) the potential that the pathway of spontaneous regression functions via increased natural killer cell activation, second to ingestion of assorted mushrooms in this case, is promising for future research efforts. The Merkel cell polyomavirus (MCV) status of this patient is, however, extremely important in progressing the findings of this case report.

I read the article “Complete spontaneous regression of Merkel cell carcinoma metastatic to the liver: Did lifestyle modifications and dietary supplements play a role?” with great interest. Merkel cell carcinoma carries a significant rate of recurrence and mortality. Though spontaneous regression of Merkel cell carcinoma has been well documented in the literature, the potential that the pathway of spontaneous regression functions via increased natural killer cell activation, second to ingestion of assorted mushrooms in this case, is promising for future research efforts. The Merkel cell polyomavirus (MCV) status of this patient is, however, extremely important in progressing the findings of this case report.

A majority of cases of Merkel cell carcinoma are associated with the MCV. These MCV-infected Merkel cell carcinomas produce T-antigens that could potentially alter immune surveillance. As treatment with type-1 interferons has demonstrated some success in treating only polyomavirus-positive but not polyomavirus-negative Merkel cell carcinoma, the viral status of the patient's tumor could significantly affect treatment with certain immunotherapies. Thus, a test for MCV in this patient could aid in further interpretation and studies based on the findings presented. Nevertheless, I thank you for presenting this interesting case.