Reply to Leah Bensimon, Samy Suissa, and Laurent Azoulay's Letter to the Editor re: Daniel E. Spratt, Chi Zhang, Zachary S. Zumsteg, Xin Pei, Zhigang Zhang, Michael J. Zelefsky. Metformin and Prostate Cancer: Reduced Development of Castration-resistant Disease and Prostate Cancer Mortality. Eur Urol 2013;63:709–16

doi:10.1016/j.eururo.2013.04.015

European Urology

Volume 64, Issue 2, August 2013, Pages e29-e30

https://doi.org/10.1016/j.eururo.2013.04.015 Get rights and content

Section snippets

Conflicts of interest

The authors have nothing to disclose.

References (3)

D.E. Spratt et al.
Metformin and prostate cancer: reduced development of castration-resistant disease and prostate cancer mortality
Eur Urol
(2013)

There are more references available in the full text version of this article.

Cited by (2)

Prostate Cancer Patients With Unmanaged Diabetes or Receiving Insulin Experience Inferior Outcomes and Toxicities After Treatment With Radiation Therapy
2017, Clinical Genitourinary Cancer
Citation Excerpt :
Second, we do not have exact start and stop times of medications; and, because 34% of our patients took medications before initiation of RT, we might have some immortal time bias, which was suggested53 to be present in the MSKCC study.11 We do not report analyses for immortal time bias because: (1) similar to the MSKCC analysis and subsequent comments of Spratt and colleagues,54 only 5% of our patients took medications after initiation of RT; in comparison, the time on any event (ie, FFBF, FFDM, CSS) is relatively long (ie, > 10 years from BF to cancer-related mortality) in prostate cancer patients55; and (2) men who were receiving any medication did not have improved outcomes. Additionally, we did not evaluate outcomes and toxicities among other fractionation schedules (eg, hypofractionation,56 stereotactic body RT57,58) or treatment modalities (eg, brachytherapy,59 brachytherapy boost26,28), although we hypothesize that outcomes and toxicities of those patients would similarly be affected.
The purpose of the study was to determine the effect of type 2 diabetes mellitus (T2DM) on outcomes and toxicities among men with localized prostate cancer receiving definitive radiation therapy.
We performed a retrospective review of 3217 patients, from 1998 to 2013, subdivided into 5 subgroups: (I) no T2DM; (II) T2DM receiving oral antihyperglycemic agent that contains metformin, no insulin; (III) T2DM receiving nonmetformin oral agent alone, no insulin; (IV) T2DM receiving any insulin; and (V) T2DM not receiving medication. Outcome measures were overall survival, freedom from biochemical failure (BF), freedom from distant metastasis, cancer-specific survival, and toxicities. Kaplan–Meier analysis, log rank tests, Fine and Gray competing risk regression (to adjust for patient and lifestyle factors), Cox models, and subdistribution hazard ratios (sHRs) were used.
Of the 3217 patients, 1295 (40%) were low-risk, 1192 (37%) were intermediate-risk, and 652 (20%) were high risk. The group I to V distribution was 81%, 8%, 5%, 3%, and 4%. The median dose was 78 Gy, and the median follow-up time was 50 (range, 1-190) months. Group V had increased mortality (sHR, 2.1; 95% confidence interval [CI], 0.66-1.54), BF (sHR, 2.14; 0.88-1.83), and cause-specific mortality (sHR, 3.87; 95% CI, 1.31-11). Acute toxicities were higher in group IV versus group I (genitourinary: 38% vs. 26%; P = .01; gastrointestinal: 21% vs. 5%; P = 001). Late toxicities were higher in groups IV and V versus group I (12%-14% vs. 2%-6%; P < .01).
Men with T2DM not receiving medication and men with T2DM receiving insulin had worse outcomes and toxicities compared to other patients.
Metformin and prostate cancer mortality: a meta-analysis
2016, Cancer Causes and Control

View full text