Association of type 2 diabetes with in-hospital complications among women undergoing breast cancer surgical procedures. A retrospective study using the Spanish National Hospital Discharge Database, 2013–2014

OBJECTIVES To compare the type of surgical procedures used, comorbidities, in-hospital complications (IHC) and in-hospital outcomes between women with type 2 diabetes mellitus (T2DM) and age-matched women without diabetes who were hospitalised with breast cancer. In addition, we sought to identify factors associated with IHC in women with T2DM who had undergone surgical procedures for breast cancer. DESIGN Retrospective study using the National Hospital Discharge Database, 2013-2014. SETTING Spain. PARTICIPANTS Women who were aged ≥40 years with a primary diagnosis of breast cancer and who had undergone a surgical procedure. We grouped admissions by T2DM status. We selected one matched control for each T2DM case. MAIN OUTCOME MEASURES The type of procedure (breast-conserving surgery (BCS) or mastectomy), clinical characteristics, complications, length of hospital stay and in-hospital mortality. RESULTS We identified 41 458 admissions (9.23% with T2DM). Overall, and in addition to the surgical procedure, we found that comorbidity, hypertension and obesity were more common among patients with T2DM. We also detected a higher incidence of mastectomy in women with T2DM (44.69% vs 42.42%) and a greater rate of BCS in patients without T2DM (57.58% vs 55.31%). Overall, non-infectious complications were more common among women with T2DM (6.40% vs 4.56%). Among women who had undergone BCS or a mastectomy, IHC were more frequent among diabetics (5.57% vs 3.04% and 10.60% vs 8.24%, respectively). Comorbidity was significantly associated with a higher risk of IHC in women with diabetes, independent of the specific procedure used.province CONCLUSIONS: Women with T2DM who undergo surgical breast cancer procedures have more comorbidity, risk factors and advanced cancer presentations than matched patients without T2DM. Mastectomies are more common in women with T2DM. Moreover, the procedures among women with T2DM were associated with greater IHC. Comorbidity was a strong predictor of IHC in women with T2DM.