Women with breast cancer
have worse health outcomes with co-occurring type 2 diabetes
, possibly due to suboptimal breast cancer
We created a cohort of women ages 66 to 85 y with stage I to III breast cancer
from 1993 to 2012 from an integrated health care delivery system (n=1612) and fee-for-service Medicare beneficiaries (n=98,915), linked to Surveillance, Epidemiology, and End Results (SEER) data (total n=100,527). We evaluated associations between type 2 diabetes
and other factors with undergoing guideline-concordant cancer treatment. We estimated χ2
tests for univariate analysis and relative risks (RRs) using multivariable log-binomial models for outcomes of (1) overall guideline-concordant treatment, (2) definitive surgical therapy (mastectomy or lumpectomy with radiation), (3) chemotherapy if indicated, and (4) endocrine therapy.
Our cohort included 60% of subjects with stage 1 tumors, one quarter below 70 years old, 23% had diabetes
, 35% underwent overall guideline-concordant treatment, 24% chemotherapy, and 83% endocrine therapy. Women with diabetes
were less likely to undergo overall guideline-concordant treatment (RR: 0.96; 95% confidence interval: 0.94-0.98), and only slightly less likely to undergo guideline-concordant definitive surgical therapy (RR: 0.99; 95% confidence interval: 0.99-1.00). No differences were found for chemotherapy or endocrine therapy. Other factors significantly associated with a lower risk of guideline-concordant care were cancer stages II to III (vs. I; RR=0.47-0.69, P
<0.0001), older age (vs. 66 to 69 y; RR=0.56-0.90, P
<0.0001), higher comorbidity burden, and Medicaid dual-eligibility.
was associated with lower adherence to overall guideline-concordant breast cancer
treatment. However, higher stage, older age, higher comorbidity burden, and Medicaid insurance were more strongly associated with lower use of guideline-concordant treatment. Given the heavy burden of breast cancer
, long-term outcomes analysis should consider guideline-concordant treatment.
Other factors besides diabetes
are more strongly associated with guideline-concordant breast cancer