(P-415) Real-world Treatment Trajectories for Newly Diagnosed Type 2 Diabetes Mellitus in Patients with Metastatic Cancer

Background: Type 2 Diabetes Mellitus (T2DM) is one of the most common comorbidities observed among cancer patients. Concurrent diagnosis of T2DM, particularly when it is poorly controlled, challenges cancer treatment and contributes to poorer patient outcomes.

Objectives: To assess real-world longitudinal treatment patterns for newly diagnosed T2DM among patients with underlying metastatic cancer.

Methods: We used Trinetx, an Electronic Health Record data network (2014-2020) that captures over 50 million US lives, to identify adult patients with metastatic breast, prostate, colorectal or lung cancer who were subsequently newly diagnosed with T2DM. T2DM treatments were organized by therapeutic class: insulin, metformin, sulfonylureas, thiazolidinediones, glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase 4 inhibitors, and sodium-glucose co-transporter inhibitors, meglitinides and alpha-glucosidase inhibitors. The choice of medications and the order they are prescribed were used to characterize the prevalence of longitudinal treatment patterns. Medications prescribed within seven days of each other were assumed to be taken concurrently. All analyses were stratified by cancer site.

Results: A total of 2480 breast, 1190 colorectal, 2039 lung and 1457 prostate cancer patients met of study’s eligibility criteria. Insulin was the most commonly used first-line treatment for T2DM among patients among the four metastatic cancers we examined, with the highest prevalence in lung cancer patients (63.1%), followed by colorectal (57.1%), prostate (43.4%) and breast (40.4%) cancer groups. Collectively insulin and metformin, the second most popular first-line treatment, accounted for over 73% of the initial T2DM prescriptions across cancer types. Notably, T2DM treatment switching rates varied by cancer site, with the highest switch rate among breast cancer patients (31.7%) and the lowest in the lung cancer cohort (20.4%). Among patients who switched treatments, the most pattern was Insulin -> Metformin -> Insulin - suggesting a temporal interaction between cancer and T2DM management strategies.

Conclusions: In clinical practice, insulin and metformin were the most common first-line T2DM treatments used by patients with comorbid metastatic cancer, and medication changes were rare. More research is needed to determine the optimal strategy for managing T2DM among cancer patients, including the potential role of newer T2DM treatments.