1811MO Association of pre-existing cardiovascular disease (CVD) in older patients with breast cancer with treatment and survival outcomes

Abstract

We aimed to determine the associations of pre-existing CVD with administration of cancer treatments and survival outcomes in older patients with breast cancer. Patients aged ≥ 65 years who were diagnosed with breast cancer from 2004 to 2015 in a large Canadian province were identified from population-based registry. Patients were categorized as old (65-74 years), older (75-84 years) and oldest (≥ 85 years). Multivariable logistic and Cox regression analyses were performed to identify associations of CVD with cancer treatment and to determine its effect on overall survival (OS). We identified 9,682 patients with breast cancer and the median age was 73 years. Of these, 54.3% were old, 32.9% were older, and 12.8% were oldest. While early breast cancer was diagnosed in 70.4%, 24.0% and 5.6% had locally advanced and metastatic disease. The prevalence of pre-existing CVD was 21.5% and increased with advancing age (13.2% in old patients vs. 40.9% in oldest patients; P<0.001). On multivariable logistic regression, CVD was associated with lower odds of receiving appropriate chemotherapy (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.42-0.68; P < .0001) and radiotherapy (OR, 0.67; 95% CI, 0.57-0.78; P < .0001), but not surgery (OR, 0.89; 95% CI, 0.76-1.04; P =0.155). The 5-year OS was lower in patients with baseline CVD as compared to those without (77.9% vs 49.8%, P <0.001). Upon adjusting for stage and treatment, CVD continued to correlate with worse survival (hazard ratio, 1.58; 95% CI, 1.46-1.71; P < .0001). The 5-year OS of the old, older, and oldest patients were 84.3%, 67.0% and 35.4%, respectively.Table:Old 65-74 yearsOlder 75-84 yearsOldest ≥ 85 yearsSurgery Odds ratio (OR) 95% Confidence interval (CI) P-value1.09 0.81-1.47 0.5630.82 0.64-1.07 0.1410.88 0.66-1.18 0.412Chemotherapy OR 95% CI P-value0.53 0.40-0.70 <0.0010.52 0.31-0.89 0.0190.40 0.05-3.08 0.381Radiotherapy OR 95% CI P-value0.69 0.55-0.89 0.0040.63 0.51-0.79 <0.0010.84 0.54-1.31 0.446 Open table in a new tab . Older patients with breast cancer and pre-existing CVD are less likely to receive chemotherapy and radiotherapy. The OS of patients with baseline CVD was worse even among those who received treatment. Early cardio-oncology involvement in advanced age patients should be an integral part of cancer management to improve their outcomes.