Patients treated for Merkel cell carcinoma (MCC) face a five-year recurrence rate of 40%—markedly higher than the recurrence rates for melanoma and other skin cancers.
These findings come from a study published in JAMA Dermatology (Feb. 23, 2022, online ahead of print).
This study included 618 patients, 37% female, whose ages ranged from 11 to 98 years. In this cohort, initial treatment—surgery, radiation and systemic therapy—had a median duration of 90 days.
In addition to the findings on the recurrence rate, the researchers also observed that 95% of MCC recurrences occurred in the first three years after treatment. They write that this suggests that surveillance efforts should be focused on that span.
“Merkel cell cancer is a life-changing diagnosis. It can be time-consuming, costly and exhausting to undergo clinic visits, imaging studies and blood draws. Now we have data on the time intervals and cancer stages that merit higher or lower surveillance intensity,” said lead researcher Dr. Aubriana McEvoy in a press release.
Dr. McEvoy led the research while she was at the University of Washington (UW) School of Medicine. She is currently a dermatology resident at Washington University in St. Louis.
Broken down by disease stage, the risk of recurrence at one year was found to be:
11% among patients diagnosed with stage I disease
33% among patients diagnosed with stages IIA/IIB disease
30% among patients diagnosed with stages IIIA disease
45% among patients diagnosed with stage IIIB disease
58% among patients diagnosed with stage IV disease
The investigators found four factors were associated with higher recurrence risk. These were advanced age, male sex, immunosuppression, and a known primary lesion amid clinically detectable nodal disease.
Survival among the patients in this cohort was also strongly dependent on cancer stage at the time of diagnosis. The MCC-specific survival rate at five years post-treatment was 95% for patients diagnosed at stage I vs. 41% for patients diagnosed at stage IV.
“This is a tricky cancer to beat because it comes back after optimal therapy in almost half of patients. We want to help patients figure out how much remaining risk of recurrence they have at various times after diagnosis,” said senior author Dr. Paul Nghiem in the release.
Dr. Nghiem is chair of dermatology at the UW School of Medicine.