Systemic therapies effective in melanoma of unknown primary

Patients with melanoma of unknown primary (MUP) benefit from novel therapies similarly as those with stage-matched melanoma of known cutaneous primary (cMKP) despite having less favourable baseline prognostic factors, reveals a study.

“They should be managed according to similar strategies,” said the researchers, who examined the efficacy and safety of systemic treatment with patients with advanced MUP relative to those with cMKP.

The research team identified patients with advanced melanoma who were treated from March 2013 to June 2021 with first-line immunotherapies, targeted therapies, or chemotherapy from the nationwide MelBase prospective database.

Progression-free and overall survival were the primary outcomes, while treatment-related toxicities were secondary. The researchers performed both multivariate and propensity score analyses.

A total of 1,882 patients were identified, of whom 265 (14.1 percent) had advanced MUP. These patients exhibited unfavourable initial prognostic factors more often than those with cMKP. However, overall and progression-free survival did not differ significantly between the two cohorts (p=0.73 and p=0.93, respectively), as did treatment-related toxicity rate and severity, irrespective of treatment type.

“Although patients with MUP had less favourable baseline prognostic factors, they benefited from the novel therapies as much as those with cMKP,” the researchers said.

This study was limited by the absence of a standard diagnostic criteria of MUP in participating centres,” they pointed out.