To assess factors associated with the higher effect of metformin on mortality in diabetic colorectal cancer (CRC) patients, since the factors related to the effectiveness of metformin have not been identified yet. Between January 2000 and December 2010, 413 patients diagnosed with both stage 3/4 CRC and diabetes mellitus were identified. Patients’ demographics and clinical characteristics were analyzed. The effect of metformin on CRC-specific mortality and the interactions between metformin and each adjusted factor were evaluated. Total follow-up duration was median 50 mo (range: 1-218 mo). There were 85 deaths (45.9%) and 72 CRC-specific deaths (38.9%) among 185 patients who used metformin, compared to 130 total deaths (57.0%) and 107 CRC-specific deaths (46.9%) among 228 patients who did not use metformin. In multivariate analysis, survival benefit associated with metformin administration was identified (HR = 0.985, 95%CI: 0.974-0.997, P = 0.012). Interaction test between metformin and sex after adjustment for relevant factors revealed that female CRC patients taking metformin exhibited a significantly lower CRC-specific mortality rate than male CRC patients taking metformin (HR = 0.369, 95%CI: 0.155-0.881, P = 0.025). Furthermore, subgroup analysis revealed significant differences in CRC-specific mortality between the metformin and non-metformin groups in female patients (HR = 0.501, 95%CI: 0.286-0.879, P = 0.013) but not male patients (HR = 0.848, 95%CI: 0.594-1.211, P = 0.365). There were no significant interactions between metformin and other adjusted factors on CRC-specific mortality. We showed a strong sex-dependent difference in the effect of metformin on CRC-specific mortality in advanced stage CRC patients with diabetes.

Few noninvasive methods can accurately identify esophageal varices (EVs) in patients with compensated cirrhosis. We developed and validated a novel, acoustic radiation force impulse (ARFI) elastography-based prediction model for high-risk EVs (HEVs) in patients with compensated cirrhosis. A total of 143 patients with compensated cirrhosis between February, 2010 and February, 2013 (training set) and 148 between June, 2010 and May, 2013 (validation set) who underwent ARFI elastography and endoscopy were prospectively recruited. Independent predictors of HEVs were used to construct a prediction model. Based on multivariate analysis, we developed two new statistical models, a varices risk score and ARFI-spleen diameter-to-platelet ratio score (ASPS), the latter of which was calculated as ARFI velocity × spleen diameter/platelet count. The area under receiver operating characteristic curve (AUROC) of the varices risk score and ASPS to predict HEVs were 0.935 (95% confidence interval [CI] 0.882–0.970) and 0.946 (95% CI 0.895–0.977), respectively. When ASPS, a simpler model with a higher AUROC, was applied in the validation set, acceptable diagnostic accuracy for HEVs was observed (AUROC = 0.814 [95% CI 0.743–0.885]). To detect HEVs, a negative predictive value of 98.3% was achieved at ASPS 5.28. ASPS, a novel noninvasive ARFI-based prediction model, can accurately identify HEVs in patients with compensated cirrhosis. ASPS 5.28 should be considered for endoscopic examinations or appropriate prophylactic treatment.