Study links high IL-12 levels, increased melanoma mortality

Houston - Data from a large cohort study shows that an elevated level of interleukin-12 is associated with a significantly increased mortality risk in patients with stage III melanoma with regional metastasis, according to MedPageToday.

According to the study, conducted by researchers at the University of Texas M.D. Anderson Cancer Center, patients with stage III disease and an IL-12 level greater than 150 pg/mL had almost a fivefold greater mortality risk than stage III patients with normal IL-12.

The study reports that IL-12 has a “paradoxical effect” on cellular immunity in that the cytokine can induce and suppress the immune system. Additionally, IL-12 has a p40 subunit in common with IL-23, which has the ability to promote tumor growth, that IL-12 levels increase with age, and that age is an adverse prognostic factor for melanoma.

The researchers measured IL-12 levels in 658 patients - 445 with stage I-II disease, 150 with stage III disease and 63 with stage IV disease. All had a median follow-up of 13 months. The study shows that, as expected, IL-12 levels increased with age: Patients younger than 40 had a mean IL-12 level of 75 pg/mL; those ages 40 to 59 had an average level of 84 pg/mL, those ages 60 to 79 had an average level of 96 pg/mL and patients 80 and older had a level of 112 pg/mL.

The study also showed patients with stage III disease and a plasma IL-12 level greater than 150 pg/mL had a mortality-hazard ratio of 4.763 compared with stage III patients who had normal IL-12 levels.

“Elevated IL-12 is an independent predictor of poor prognosis in patients with regionally advanced melanoma,” the study’s authors report. “The association between IL-12 and advanced age could help explain the link between age and poorer prognosis in melanoma. Elevated IL-12 may be a marker of an immunosuppressive, tumor-promoting response in melanoma patients.”