Antidiabetic therapies and malignancy: a retrospective study in oncological cases.

C. Anil; C. Demir; B. Erismis; S. Can; S. Yalcin; O. Altundag; G. Gunes; Tutuncu N. Bascil

Introduction: Despite the relation between Type 2 Diabetes Mellitus (DM) and development of malignancy is well known, data on antidiabetic drugs and cancer risk is contradictory. Thesis which have suggested that analogue insulins, especially glargine, increase cancer risk, has not been validated. The present study aimed to evaluate the possible contributions of diabetes durations and medications to the type and course of malignancy in patients with both diabetes and malignancy.

Methods: Among patients registered in the Oncology department of Baskent University Hospital, those who had DM before the oncological diagnoses were enrolled. The course of diabetes, antidiabetic medications and their relevance to the oncological diagnoses were examined.

Results: Totally, 246 patients were enrolled. Some characteristics of the group were summarized in Table 1. Among 69 patients receiving insulin, no relation was determined between duration of DM, basal glycohemoglobin values and stage of malignancy at diagnosis and the course of malignancy. There was no relation between the type and duration of antidiabetic therapy used (including metformin, glargine insulin) and the type of malignancy, stage at diagnosis and the final state of malignancy.

Conclusion: Despite this retrospective study may not give idea about possible cancer initiating or promoting potential of antidiabetic medications, it may suggest that therapies put forward to be protective (such as metformin) or risk increasing (such as glargine) might not have any influence on the type and biological behavior of the developing malignancy. Prospectively designed research is required to exhibit these relations clearly.

Some features and results of the study

Table 1
N (female / male)	246 (132/114)
Age (years, mean±S.D.)	70.3±11.3
Distribution of antidiabetic therapy*, N (%)	No treatment-29 (11.8) OAD- 148 (60.2) Insulin- 69 (28)
Malignancy types, N (%) (most frequent)	Breast- 40 (16.2) Prostate- 27 (11) Thyroid- 24 (9.8) Colorectal- 20 (8.1) Renal cell- 15 (6.1) Other- 120 (48.8)
Distribution of antidiabetic therapy until diagnosis of malignancy **, N	No treatment- 29 Metformin- 196 Other OAD- 208 Insulin- Non-analogue- 37 Glargine- 7 Other analogue- 25
Time between diagnosis of DM and malignancy, (years, mean±S.D.)	16.1±11.0
Glycohemoglobin level at the time of diagnosis of malignancy (%, mean±S.D.)	8.0±1.9
Duration of metformin use, years (minimum-maximum)	1–38
Duration of insulin glargine use, years (minimum-maximum)	2–10
Those using insulin for at least 6 months between DM and malignancy diagnoses were included in insulin group.* Those drugs used for at least 6 months were included.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector

Endocrine Abstracts

P714