Preoperative cancer cachexia and short-term outcomes following surgery.

BACKGROUND: Cancer cachexia is an important measure of physiologic reserve associated with worse survival and represents an actionable factor for the cancer population. However, the incidence of cachexia in surgical cancer patients and its impact on postoperative outcomes are currently unknown.

METHODS: A prospective cohort study enrolling patients having elective cancer surgery (2012-2014) at a Veterans Affairs tertiary referral center. Preoperative cancer cachexia (weight loss ≥5% over 6-mo period before surgery) was the predictor of interest. The primary outcome was 60-d postoperative complications (VA Surgical Quality Improvement Program). Patients were grouped by body mass index (BMI) category (<25, 25-29.9, ≥30), and interaction between cachexia and BMI was tested for the primary outcome. Multivariate logistic regression was used to examine the association between preoperative cachexia and postoperative complications.

RESULTS: Of 253 patients, 16.6% had preoperative cachexia, and 51.8% developed ≥ 1 postoperative complications. Complications were more common in cachectic patients (64.3% versus 49.3%, P = 0.07). This association varied by BMI category, and interaction analysis was significant for those with normal or underweight BMI (BMI < 25, P = 0.03). After multivariate modeling, in patients with normal or underweight BMI, preoperative cachexia was associated with higher odds of postoperative complications (odds ratios, 5.08 [95% confidence intervals, 1.18-21.88]; P = 0.029). Additional predictors of complications included major surgery (3.19 [1.24-8.21], P = 0.01), ostomy (4.43 [1.68-11.72], P = 0.003), and poor baseline performance status (2.31 [1.05-5.08], P = 0.03).

CONCLUSIONS: Cancer cachexia is common in surgical patients, and is an important predictor of postoperative complications, though its effect varies by BMI. As a modifiable predictor of worse outcomes, future studies should examine the role of cachexia treatment before cancer surgery.