ICIs improve survival in advanced MCC at population level

Treatment of immune checkpoint inhibitors (ICIs) has led to a more than twofold increase in survival for patients with advanced Merkel cell carcinoma (MCC) at the population level, translating to about 220 fewer deaths annually in the US, according to a study.

Researchers performed this cohort study to evaluate whether the introduction of ICIs in the US could improve survival in MCC patients. They analysed data from the Surveillance, Epidemiology, and End Results (SEER) for patients who had been diagnosed with MCC between 2010 and 2021, grouped by 3-year periods, and assessed 2-year overall and relative survival.

A total of 4,786 MCC patients were included in the analysis. Of these, 453 had metastatic disease. At 2 years, relative survival rose from 23 percent (2010‒2012) to 37 percent (2013‒2015), 42 percent (2016‒2018), and 54 percent (2019‒2021; p<0.001). Median overall survival also improved from 9 to 16 months among metastatic patients.

Similarly, 2-year relative survival in all MCC patients improved from 73 percent (2010‒2012) to 81 percent (2019‒2021; p=0.004), while overall survival rose from 67 percent to 72 percent (p=0.012).

This study was limited by the lack of case-level data in SEER that could directly link ICI treatment to survival. However, ICIs “represent major recent treatment advance for MCC,” the researchers said.

MCC is an aggressive form of skin cancer that has poor survival rates. On the other hand, ICIs were approved by the FDA for MCC in 2017.