Postoperative hyperphosphatemia significantly associates with adverse survival in colorectal cancer patients

Hyperphosphatemia has been implicated in the development and treatment of various cancers. However, whether it can be used as a direct prognostic marker of colorectal cancer (CRC) has remained unexplored. Given new insights into the importance of hyperphosphatemia in CRC, we sought to evaluate the association of hyperphosphatemia with the clinical outcomes of this disease.

In a retrospective analysis of a well-characterized clinic-based cohort with 1241 CRC patients, we assessed the association of postoperative hyperphosphatemia with patient overall survival.

Postoperative hyperphosphatemia measured within the first month after surgery was significantly associated with CRC survival. Compared to patients with a normal phosphate level, those with hyperphosphatemia exhibited a significant unfavorable overall survival with a hazard ratio (HR) of 1.84 (95% confidence interval [CI] 1.49-2.29, P = 2.6 × 10(-8) (log-rank P = 1.2 × 10(-7) ). Stratified analyses indicated the association was more pronounced in patients with colon (HR = 2.00, 95% CI 1.57-2.56, P = 3.17 × 10(-8) ) but not rectal cancer (HR = 0.96, 95% CI 0.58-1.59, P = 0.889) (P interaction = 0.023), as well as in those not receiving chemotherapy (HR = 2.15, 95% CI 1.59-2.90, P = 6.2 × 10(-7) ) but not in those receiving chemotherapy (HR = 1.30, 95% CI 0.92-1.82, P = 0.136) (P interaction = 0.012). Flexible parametric survival model demonstrated that the increased risk for death conferred by postoperative hyperphosphatemia persisted over 150 months after surgery.

Our data indicated that postoperative hyperphosphatemia might be used as a prognostic marker of CRC patients after surgery. Since phosphate level is routinely tested in clinics, it may be incorporated into clinical models to predict CRC survival.