Body Mass Index and Total Psoas Area Affect Outcomes in Patients Undergoing Pneumonectomy for Cancer

Abstract

Hypothesizing that morphometric measurements are reliable markers of fitness in patients with lung cancer requiring aggressive surgical intervention, the purpose of this study was to assess their impact on postoperative outcome and long-term survival in patients with non-small cell lung cancer (NSCLC) requiring pneumonectomy. Height, weight, and body mass index (BMI), as well as usual clinical, laboratory (including C-reactive protein [CRP] concentrations), and pathologic data were retrospectively retrieved from files of 161 consecutive patients treated by pneumonectomy for NSCLC, whose preoperative computed tomographic (CT) scans were available in the Picture Archive and Communication System (PACS) of the hospital. Cross-sectional areas of right and left psoas areas (measured by CT scan at the L3 level), perirenal fat thickness, and anterior subcutaneous tissue thickness at the left renal vein level were also assessed. BMI and total psoas area were strongly and directly correlated (p= 0.0000001), whereas BMI was inversely related to CRP levels. Sarcopenia (total psoas area ≤33rd percentile) was associated with high CRP levels (>20 mg/L) (p= 0.010). Factors associated with 90-day mortality included older age (p= 0.000045), lower body weight (p= 0.032), and BMI less than or equal to 25 kg/m2 (p= 0.013). At univariate analysis, long-term outcome was negatively affected by a nonsquamouscell histologic type (p= 0.011), pathologic stage IIIB-IV (p=0.026), CRP levels greater than 20mg/L (p= 0.017), BMI less than or equal to 25 kg/m2 (p= 0.010), and total psoas area less than or equal to the 33rd percentile (p= 0.029). Multivariate analysis showed the independent prognostic value of both BMI and total psoas area. BMI less than or equal to 25 kg/m2 and total psoas cross-sectional area less than or equal to the 33rd percentile are prognostic determinants in patients with NSCLC requiring pneumonectomy.