Lower Pectoralis Muscle Area Is Associated with a Worse Overall Survival in Non-Small Cell Lung Cancer.

BACKGROUND: Muscle wasting is a component of the diagnosis of cancer cachexia and has been associated with poor prognosis. However, recommended tools to measure sarcopenia are limited by poor sensitivity or the need to perform additional scans. We hypothesized that pectoralis muscle area (PMA) measured objectively on chest CT scan may be associated with overall survival (OS) in non-small cell lung cancer (NSCLC).
METHODS: We evaluated 252 cases from a prospectively enrolling lung cancer cohort. Eligible cases had CT scans performed prior to the initiation of surgery, radiation, or chemotherapy. PMA was measured in a semi-automated fashion while blinded to characteristics of the tumor, lung, and patient outcomes.
RESULTS: Men had a significantly greater PMA than women (37.59 vs. 26.19 cm2, P < 0.0001). In univariate analysis, PMA was associated with age and body mass index (BMI). A Cox proportional hazards model was constructed to account for confounders associated with survival. Lower pectoralis area (per cm2) at diagnosis was associated with an increased hazard of death of 2% (HRadj, 0.98; confidence interval, 0.96-0.99; P = 0.044) while adjusting for age, sex, smoking, chronic bronchitis, emphysema, histology, stage, chemotherapy, radiation, surgery, BMI, and ECOG performance status.
CONCLUSIONS: Lower PMA measured from chest CT scans obtained at the time of diagnosis of NSCLC is associated with a worse OS. IMPACT: PMA may be a valuable CT biomarker for sarcopenia-associated lung cancer survival. Cancer Epidemiol Biomarkers Prev; 26(1); 38-43. ©2016 AACR SEE ALL THE ARTICLES IN THIS CEBP FOCUS SECTION, "THE OBESITY PARADOX IN CANCER EVIDENCE AND NEW DIRECTIONS". ©2016 American Association for Cancer Research.