Secondary neoplasms in mycosis fungoides: evaluating risk factors and phototherapy impact in a comparative study.

Patients with mycosis fungoides (MF) are at an increased risk of developing secondary neoplasms. We conducted a comparative analysis between MF patients with and without secondary neoplasms and non-MF patients to assess secondary neoplasm occurrence and identify potential risk factors. We aimed to evaluate the prevalence of secondary neoplasms and investigate associated risk factors in MF patients. Demographic data, treatments, phototherapy details, neoplasm occurrence and detection time, and mortality rates were collected and retrospectively analyzed for 252 MF and 278 control patients. The prevalence of secondary neoplasms was significantly higher in the MF group (13.9%) compared to the control group (3.6%) (p < 0.001). MF patients with neoplasms had a higher average age and older age at MF diagnosis (p = 0.003 and 0.016, respectively). Phototherapy type showed no significant association with neoplasm presence. Elevated initial and final beta-2 microglobulin levels were observed in MF patients with neoplasms (p = 0.002 and 0.005, respectively). MF patients have a higher risk of developing secondary neoplasms compared to controls. Risk increases with older age at MF diagnosis and elevated beta-2 microglobulin levels. Phototherapy was not associated with the development of secondary neoplasms in MF patients. MF patients with secondary neoplasms exhibit higher mortality rates, underscoring the importance of early detection and vigilant monitoring.