Body mass index, C-reactive protein and survival in smokers undergoing lobectomy for lung cancer†

Cachexia has been shown to be related to mortality in patients with advanced cancers and chronic obstructive pulmonary disease. Smokers receiving surgery for lung cancer are thought to be at risk of developing cachexia postoperatively. We aimed to investigate whether 2 surrogate variables for cachexia, body mass index (BMI) and C-reactive protein (CRP) level, are predictive of mortality in smokers after complete resection of non-small-cell lung cancer.

We retrospectively examined 678 patients who underwent curative lobar resection for non-small-cell lung cancer at our hospital. Associations between clinicopathological factors and overall survival were assessed in smokers ( N  = 421) and never smokers ( N  = 257).

Multivariate analysis of the smokers group showed that preoperative BMI ≤ 20.6 kg/m 2 and CRP ≥ 0.13 ng/ml were risk factors for poorer prognosis, independent of age and pathological stage. In never smokers, BMI and CRP were not significantly associated with survival. Smokers in the high-risk group, defined based on preoperative BMI and CRP, had shorter survival after recurrence, although they did not have an elevated recurrence rate. Despite the absence of recurrence, they died more frequently of pneumonia or other cancers. These observations are consistent with the idea that the poor postoperative prognosis could have resulted from the progression of cachexia.

In smokers with non-small-cell lung cancer, preoperative low BMI and elevated CRP are predictive factors for poor prognosis after complete resection, probably as a result of cachexia progression. The effective treatment of cachexia might improve postoperative prognosis.