The impact of metformin on survival in diabetes patients with operable colorectal cancer: A nationwide retrospective cohort study.

OBJECTIVE: To investigate the impact of metformin on survival of diabetic patients following surgery for colorectal cancer (CRC). METHODS: This was a retrospective cohort study. From Taiwan's population-based National Health Insurance Research Database (NHIRD) we identified 12,512 patients with CRC and type II diabetes who underwent curative surgery between 2000 and 2012. Of these, 6222 patients were included in a matched cohort. Using Cox regression models with time-dependent covariates we examined the impact of metformin on survival. RESULTS: Average duration of follow-up was 49 and 54 months for metformin users and non-users, respectively. Cox proportional hazard model showed that metformin was associated with 5-year overall survival benefit (Hazard ratio, 0.23 [95% CI, 0.20-0.26]) and inverse association with risk of liver metastasis (Hazard ratio, 0.79 [95% CI, 0.68-0.93]). CONCLUSIONS: Metformin was associated with a survival benefit in diabetic patients with CRC following surgery, and an inverse association with risk of liver metastases suggesting a potential anti-tumorigenic effect.

Pneumocystis jirovecii pneumonia in HIV-uninfected, rituximab treated non-Hodgkin lymphoma patients.

Rituximab is associated with a higher incidence of Pneumocystis jirovecii pneumonia infection. Pneumocystis prophylaxis is advised in many immunocompromised populations treated with rituximab. However, the beneficial effect of pneumocystis prophylaxis in HIV-uninfected, rituximab-treated non-Hodgkin lymphoma (NHL) patients has not been assessed. Thus, we conducted this retrospective study to explore pneumocystis infection in HIV-uninfected NHL patients who received at least three courses of chemotherapy without haematopoietic stem cell transplantation using the Taiwan National Health Insurance Research Database. Patients who had rituximab-based chemotherapy were included in the experimental (rituximab) group, while the rest of the patients who did not receive any rituximab-based chemotherapy throughout the study period formed the control group. The prevalence rate of pneumocystis infection in the rituximab group (N = 7,554) was significantly higher than that in the control group (N = 4,604) (2.95% vs. 1.32%). The onset of pneumocystis infection occurred between 6 and 16 weeks after chemotherapy. Patients who had pneumocystis prophylaxis, whether or not they had a pneumocystis infection later in their treatment course, had significantly better first-year survival rates (73% vs. 38%). Regular pneumocystis prophylaxis should be considered in this group of patients.