High HbA1c Levels Are Associated With Poor Prognosis in Patients With Breast Cancer

Researchers analyzed 2514 women diagnosed with stage I-III BC during 2010-2020 who all provided blood samples at the time of BC diagnosis and did not have diabetes diagnosed at the time of the blood draw. HbA1c levels were categorized and divided into quartiles. Patients in the population of interest were followed from the date of surgery to the first BC recurrence, contralateral BC, mortality, emigration, or end of follow-up.

Results Highlight Need for Metabolic Screening

After a total of 14,126 years of follow-up, investigators observed 205 recurrences, 43 contralateral BCs, and 271 deaths. The results showed that patients who fell within the highest HbA1c quartile (Q4) had an increased risk of recurrence compared with those in the lowest HbA1c quartile (Q1) in both crude and adjusted analyses (HbA1c-Q4: crude hazard ratio [HR], 1.72; 95% CI, 1.19-2.47; adjusted HR, 1.82; 95% CI, 1.17-2.81). Moreover, an increased risk of recurrence was observed per mmol/mol HbA1c increase, although the researchers noted it was less clear in the adjusted analysis (crude HR. 1.02; 95% CI, 1.00-1.04; adjusted HR, 1.01; 95% CI, 0.99-1.04). Overall, the study found that patients in Q4 had an increased risk of death (HbA1c-Q4: crude HR, 1.88; 95% CI, 1.35-2.61) compared with those in Q1.