Association between prior use of anti-diabetic medication and breast cancer stage at diagnosis

ABSTRACT

Background

Knowledge regarding antidiabetic medication (ADM) use prior to breast cancer (BC) diagnosis remains limited. The objectives were to (1) evaluate if the prior use of ADM was associated with BC stage at diagnosis and (2) identify and compare patient characteristics among BC patients using different ADMs.

Research design and methods

Newly diagnosed female BC patients exposed to any medication during one year prior to cancer diagnosis were identified in 2008–2013 Linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Stage at diagnosis, categorized as early and advanced, was the primary outcome. Chi-square tests were used to compare characteristics and logistic regression models were applied to examine the effect while controlling for patient’s characteristics.

Results

A total of 1,719 female BC patients used ADM while 6,084 patients were non-ADM users. Although a higher proportion of ADM users (20.36%) were diagnosed with advanced stage compared to the non-ADM users (14.46%), the difference was not statistically significant after adjusting for the patients’ characteristics. Besides, insulin users were more likely to be diagnosed with advanced stage (adjusted odds ratio 1.69; 95% CI 1.15, 2.48) compared to metformin users.

Conclusions

The association between ADM use and BC diagnostic characteristics varied based on different treatments.

KEYWORDS:

• Breast cancer
• diabetes
• stage at diagnosis
• medicare beneficiaries

Acknowledgments

This study used the linked SEER-Medicare database. The interpretation and reporting of these data are the sole responsibility of the authors. The authors acknowledge the efforts of the National Cancer Institute; the Office of Research, Development and Information, CMS; Information Management Services (IMS), Inc.; and the Surveillance, Epidemiology, and End Results (SEER) Program tumor registries in the creation of the SEER-Medicare database. This study results were presented, in parts, in the 35th International Conference on Pharmacoepidemiology & Therapeutic Risk Management, Pennsylvania Convention Center, Philadelphia, PA, USA, August 24–28, 2019. The appropriate reference is given below:

Fahim SM, Hsu C, Qian J, Chou C. Impact of antidiabetic medication use on breast cancer diagnostic characteristics. Pharmacoepidemiology and Drug Safety, 2019; Volume 28, Issue: S2 (abstract 404).This work was supported by Auburn University Research Initiative in Cancer (AURIC).

Author contributions

Shahariar Mohammed Fahim: Acquisition, analysis, and interpretation of data; writing–initial draft; and writing–review and editing. Chiu-Hsieh Hsu: Analysis, and interpretation of data; and writing–review and editing. Fang-Ju Lin: Analysis, and interpretation of data; and writing–review and editing. Jingjing Qian: Study concept and design; acquisition, analysis, and interpretation of data; and writing–review and editing. Chiahung Chou: Study concept and design; acquisition, analysis, and interpretation of data; writing–initial draft; writing–review and editing; and study supervision.

Consent for publication

This study did not include any individual person’s data in any form, therefore, consent for publication was not required.

Data availability

The data that support the findings of this study are available from Information Management Services, Inc. (IMS), the information technology contractor for National Cancer institute (NCI), but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of Information Management Services, Inc. (IMS).

Ethics approval and consent to participate

This study was approved by the Auburn University Institutional Review Board. This study did not include any human participants. No informed consent was required since this study used secondary data.

Disclosure statement

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This work was supported by the Auburn University Research Initiative in Cancer (AURIC).