Low Thoracic Skeletal Muscle Area Predicts Morbidity After Pneumonectomy for Lung Cancer.

BACKGROUND: Sarcopenia represented by low psoas muscle area is associated with increased hospital length of stay (LOS), postoperative complications, and mortality. We studied whether thoracic skeletal muscle area (TSMA) derived from computed tomography (CT) predicts morbidity after pneumonectomy for lung cancer. METHODS: Consecutive patients who underwent pneumonectomy for lung cancer from 2005 to 2017 were retrospectively analyzed. TSMA was defined as the sum of muscle area at the level of the eighth and the 12th thoracic vertebral bodies on preoperative CT. Patients were stratified into sex-specific TSMA quartiles for univariate time-to-event analyses. The effect of continuous TSMA measurements on operative complications, hospital and intensive care unit (ICU) LOS, discharge disposition, and hospital readmission within 90 days was estimated using multivariable models adjusted for age, sex, body mass index, forced expiratory volume in 1 second, Zubrod score, and pneumonectomy type. RESULTS: Standard (n = 102, 78.5%) or high-risk (n = 28, 21.5%; extrapleural: n = 3, 2.3%; carinal: n = 9, 6.9%; completion: n = 16, 12.3%) pneumonectomy was performed in 130 patients (60.8 ± 10.6 years; 43.1% women). Major complications occurred in 33.1% (n = 43 of 130) and readmission in 17.7% (n = 23 of 130) of patients. In multivariable models, patients with high TSMA experienced fewer overall (odds ratio [OR], 0.87; P = .04) and cardiopulmonary (OR, 0.86; P = .04) complications, and fewer readmissions (OR, 0.78; P = .01). Associations with ICU LOS (hazard ratio, 1.08; P = .051) and hospital LOS (hazard ratio, 1.05; P = .18) did not reach significance. CONCLUSIONS: TSMA predicts adverse outcome after pneumonectomy for lung cancer. This marker, readily derived from standard chest CT, identifies patients at increased risk for postoperative complications and may help select patients appropriate for focused rehabilitation before pneumonectomy.

Preoperative thoracic muscle area on computed tomography predicts long-term survival following pneumonectomy for lung cancer.

OBJECTIVES: To assess the prognostic role of thoracic muscle as quantified on preoperative computed tomography (CT) for the estimation of overall survival (OS) following pneumonectomy. METHODS: Muscle cross-sectional area (CSA) at the level of the fifth (T5) and eighth (T8) thoracic vertebra was measured on CT scans of consecutive patients with lung cancer prior to pneumonectomy. We stratified patients into high and low muscle groups using the gender-specific median of muscle CSA as separator and estimated associations of muscle CSA and OS using the Kaplan-Meier analysis. Multivariable logistic regression adjusted for body mass index, Charlson comorbidity index (includes age), forced expiratory volume in the first second as a % of predicted, sex, race, smoking status, tumour stage and prior lung cancer treatment was performed. RESULTS: A total of 128 patients were included (61.0 ± 10.6 years of age, mean body mass index of 26.9 kg/m2, 55.5% men). The T8 level showed fewer artefacts and strong correlation with the T5 level (Pearson's rho = 0.904). T8 CSA was therefore used for subsequent analyses. Mean T8 CSA was 118.5 cm2 (median 115.3 cm2) in men and 75.2 cm2 (median 74.0 cm2) in women. During a median follow-up of 23.6 months (interquartile range 39.3), 65 patients (50.8%) died, of whom 41 were in the low muscle group. The Kaplan-Meier analysis showed significantly longer OS in the high muscle group (log-rank P = 0.02). Multivariable analysis showed an independent association of muscle CSA and OS (P = 0.02) with a hazard ratio of 0.80 (confidence interval 0.67-0.98) per 10-cm2 increment. CONCLUSIONS: Thoracic muscle is independently associated with long-term overall survival following pneumonectomy for lung cancer and may contribute to refined survival estimates in this population. IRB PROTOCOL: Protocol #2017P000650, approved 21 April 2017.

Thoracic Skeletal Muscle Is Associated With Adverse Outcomes After Lobectomy for Lung Cancer.

BACKGROUND: Assessment of risk associated with lung cancer resection is primarily based on evaluation of cardiopulmonary function and remains imprecise. We investigated the relationship between thoracic muscle and early outcomes after lobectomy. METHODS: Cross-sectional area of skeletal muscle was measured at the level of the fifth thoracic vertebra on computed tomography in 135 consecutive patients before lobectomy for lung cancer. Patients were stratified into low and high muscle groups using the sex-specific muscle median. Primary outcome was a composite of any postoperative complication as per The Society of Thoracic Surgeons General Thoracic Surgical Database. Secondary outcomes included postoperative respiratory complications, postoperative intensive care unit admission, hospital length of stay, and hospital readmission within 30 days of hospital discharge. The χ2 test, adjusted multivariable regression analysis, and likelihood ratio test were performed. RESULTS: Patients with low muscle were significantly more likely to have any postoperative complication and respiratory postoperative complications. Although postoperative intensive care unit admission was similar for low muscle and high muscle groups, low muscle patients had longer hospital length of stay and a higher rate of hospital readmission. Adjusted multivariable regression revealed the independent association of thoracic muscle with all outcomes. The likelihood ratio test suggested that thoracic muscle adds predictive capability to information captured by preoperative pulmonary function testing. CONCLUSIONS: Low thoracic muscle is independently associated with increased postoperative complications and health care utilization among patients undergoing lobectomy for lung cancer. Evaluation of thoracic muscle may enhance risk prediction models.