Sarcopenia associated with DFS, distant DFS in melanoma

Sabel MS. Ann Surg Oncol. 2011;doi:10.1245/s10434-011-1976-9

Issue: October 10, 2011

People with melanoma who have lower muscle density are at an increased risk for disease recurrence, despite tumor size or patient age, according to researchers at the University of Michigan Comprehensive Cancer Center.

"Several hypotheses proposed to explain the worse prognosis for older melanoma patients include different tumor biology and diminished host response,” the researchers wrote. “If the latter were true, then biologic frailty, and not age, should be an independent prognostic factor in melanoma."

To test this hypothesis, researchers used their own prospective, institutional review board-approved database to identify 101 patients with stage III melanoma who had CT scans at the time of lymph node dissection. They determined psoas area and psoas density, and their affect on survival and surgical complications. The average age of patients with positive sentinel lymph nodes was 49.0 years and the average age of patients with clinical disease was 55.9 years.

According to Cox multivariate modeling, which incorporated thickness, age, ulceration and tumor stage, psoas density was significantly associated with both DFS (P=.04) and distant DFS (P=.0002). Breshlow thickness, number of positive nodes, ulceration and decreasing muscle density were all associated with distant DFS (P=.04; P=.001; P=.04 and P=.01, respectively). The HR was 0.55 (95% CI, 1.016-1.150).

"While frailty increases with increasing age, it must be distinguished from the aging process; most older individuals do not exhibit the phenotype of frailty, and many younger individuals may exhibit objective evidence," the researchers wrote. "This study provides objective data supporting the hypothesis that, in melanoma, host biology, in addition to tumor biology, is important in disease progression."

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