Preoperative body composition is influenced by the stage of operable pancreatic adenocarcinoma but does not predict survival after Whipple's procedure

Abstract

Objectives: Cachexia is common in pancreatic cancer and may have an influence on longterm survival but few studies have investigated this in patients with operable tumours. Therefore, this study was carried out to document body composition status in patients with pancreatic adenocarcinoma (PCa) presenting for a Whipple's procedure (WP) and to relate the findings to histopathology and longterm survival.

Methods: Body composition was measured 1 day before a WP for ductal PCa in 36 patients (15 men, 21 women) aged 41-81 years. Results for total body nitrogen (TBN), nitrogen index (NI), total body water (TBW), fat mass (FM) and total body potassium (TBK) were compared with results in 73 age- and sex-matched controls. Patients' survival and details from histopathology synoptic reports were documented.

Results: Patients undergoing WPs had low TBK values (P < 0.001) and females had lower body fat (P = 0.007) compared with controls. Five of 36 presented with significant protein deficiency, but this was not associated with a prolonged length of stay or reduced survival. The 12 patients who had involved surgical margins had larger tumours and reduced weight (P = 0.015), FM (P = 0.001), TBN (P = 0.045), TBK (P = 0.014) and survival (P = 0.036). However, multivariate Cox's regression analysis only included FM along with vascular invasion and margin status as independent predictors of survival.

Conclusions: PCa patients undergoing a WP have reduced body fat and TBK compared with community controls while those with stage III tumours had greater deficits of fat, TBK and protein stores. However, preoperative body composition was a poor predictor of postoperative survival after pathological data were considered.

Figure 1

Kaplan–Meier survival curves for the effect of vascular invasion on survival. The broken line indicates cases with vascular invasion by tumour. Log-rank significance: P= 0.004

Figure 2

Kaplan–Meier survival curves for the effect of involved surgical margins on survival. The broken line indicates cases with involved surgical margins. Log-rank significance: P= 0.048

Figure 3

Kaplan–Meier survival curves for the effect of nitrogen index (NI) on survival. The broken line indicates NI < 0.95. Log-rank significance: P= 0.44