Immunotherapy given before surgery cut melanoma's return by 40 percent

A national trial run through the SWOG cancer research network tested the opposite order on patients with resectable, advanced melanoma: three doses of pembrolizumab before the tumor came out, then more afterward.

Researchers led by Sapna Patel at MD Anderson Cancer Center randomly assigned 313 patients with stage III or IV melanoma to that sequence or to the standard adjuvant-only schedule. At two years, 72 percent of the neoadjuvant group had no recurrence, progression, or death, versus 49 percent of the other group.

The trial built on an older idea: while the tumor still sits in the body, it works as its own vaccine, letting the immune system learn against a fuller set of its antigens before the surgeon removes it. Side effects were similar between groups. The approach has not yet reset standard treatment nationwide, and researchers are still tracking how long the benefit lasts.

Sequence mattered more than the drug.