, and more than half of all patients with stage IV disease will have a recurrence within 1 year of definitive therapy, results of a new study show.
A study of 618 patients with MCC who were enrolled in a Seattle-based data repository shows that among all patients the 5-year recurrence rate was 40%. The risk of recurrence within the first year was 11% for patients with pathologic stage I disease, 33% for those with stage IIA/IIB disease, 45% for those with stage IIIB disease, and 58% for patients with pathologic stage IV MCC.
Approximately 95% of all recurrences happened within 3 years of the initial diagnosis, report Aubriana McEvoy, MD, from the University of Washington in Seattle, and colleagues.
“This cohort study indicates that the highest yield (and likely most cost-effective) time period for detecting MCC recurrence is 1-3 years after diagnosis,” they write in a study published online in JAMA Dermatology.
The estimated annual incidence of MCC in the United States in 2018 was 2,000 according to the American Cancer Society. The annual incidence rate is rising rapidly, however, and is estimated to reach 3,284 by 2025, McEvoy and colleagues write.
Although MCC is known to have high recurrence rates and is associated with a higher mortality rate than malignant melanoma, recurrence rate data are not captured by either the Surveillance, Epidemiology, and End Results (SEER) database or by the National Cancer Database. As a result, estimates of recurrence rates with MCC have been all over the map, ranging from 27% to 77%, depending on the population studied.
But as senior author Paul Nghiem, MD, PhD, professor and chair of dermatology at the University of Washington, Seattle, told this news organization, recurrence rates over time in their study were remarkably consistent.
“The biggest surprise to me was that, when we broke our nearly 20-year cohort into three 5- or 6-year chunks, every one of the groups had a 40% recurrence rate, within 1%. So we feel really confident that’s the right number,” he said.
Dr. Nghiem and colleagues report that, in contrast to patients with MCC, approximately 19% of patients with melanoma will have a recurrence, as will an estimated 5%-9% of patients with squamous cell carcinoma and 1%-10% of patients with basal cell carcinoma.
The fact that recurrence rates of MCC have remained stable over time despite presumed improvements in definitive therapy is disappointing, Dr. Nghiem acknowledged. He noted that it’s still unclear whether immunotherapy will have the same dramatic effect on survival rates for patients with MCC as it has for patients with malignant melanoma.
The high recurrence rates following definitive therapy for patients with early-stage disease was a novel finding, commented Shawn Demehri, MD, PhD, director of the high-risk skin cancer clinic at Massachusetts General Hospital in Boston.
“When you’re looking at patients with stage I or stage II, and they have definitive surgery but still have recurrences at a higher rate than melanoma, it brings home the point that these are among the most aggressive tumors of the skin,” he said in an interview.
The high recurrence rates seen with MCC are attributable to a variety of factors.
“This is a rare cancer of mostly older individuals with a lot of comorbidities, and also a cancer that, even though it is a primary cancer, might be detected a little later than even a melanoma primary tumor, just because of the nature of the neuroendocrine tumor cells,” he said.
Dr. Demehri was not involved in the study.