(ChemotherapyAdvisor) – Two of four clinical characteristics — BMI <25 kg/m2, preoperative current smoking, drinking alcohol less than twice monthly, and low histological grade — predicted nonadherence to adjuvant endocrine treatment in patients with breast cancer, according to a study in Cancer Prevention Research online March 8.
Investigators utilized a population-based prospective cohort to obtain clinical characteristics and information on adherence from 417 patients with breast cancer. Patient charts, pathology reports, and questionnaires completed at one-year and two-year follow-up visits were reviewed. Nonadherence to endocrine treatment was 8.6% (n=36) at the one-year follow-up and 7.9% (n=33) at the two-year follow-up; 13 patients had declined treatment; therefore, it was not prescribed.
At the one-year visit, relative risk (RR) was 5.24 and, at the two-year visit, 4.07, investigators from Lund University, Lund, Sweden, reported. When low histological grade was added to the model, having at least two of these four clinical characteristics predicted nonadherence at the one-year (RR 4.94) and two-year visits (RR 4.74). Sensitivity ranged from 60.6% to 72.7% and specificity from 68.0% to 78.4%. At the one-year visit, nonadherence was associated with an increased risk for early breast-cancer events (HR, 2.97), adjusted for age and tumor characteristics.
If validated in an independent cohort, these clinical profiles “may allow for targeted interventions to increase adherence,” they concluded.