Abstract
Background
Contemporary treatment options for breast cancer have significantly improved survival during the last two decades. To estimate cancer survival, current practice typically relies on cancer size and the presence of metastases, whereas cardiovascular comorbidities such as atrial arrhythmias are typically not taken into account.
Aim
To evaluate the incidence of atrial fibrillation and flutter among curatively treated breast cancer patients and assess its impact on survival in an all-comer population at a tertiary care centre.
Methods
In a large, single centre, retrospective study we enrolled all patients with a diagnosis of breast cancer in 2007 and 2008 who received radiation therapy as part of their curative treatment regimen. We performed Kaplan-Meier and Cox survival analyses to calculate mortality risk over 10-year follow up.
Results
We included 1338 patients, 1326 (99.1%) of whom were women. Mean age (± standard deviation) at diagnosis was 57.6±13.4 years and the distribution of left sided breast cancer versus right sided or bilateral breast cancer was 655 (49.0%) patients versus 645 (48.2%) and 38 (2.9%) patients, respectively. A total of 805 (60.1%) patients had at least one ECG recorded during the 10 year follow up. In this subgroup, atrial fibrillation or flutter was present in 70 (8.7%); 23 patients had pre-existing atrial fibrillation or flutter (32.9%), 26 patients had had radiation therapy for left sided breast cancer (37.1%) versus 21 patients for right sided breast cancer (30%; p=0.375 for left versus right sided radiation therapy). Of the total cohort, 327 (24.4%) patients died during 10 year follow-up. In the subgroup with at least a single ECG recording, mortality equaled 44.3% (31/70) in patients with one or more documented episodes of atrial fibrillation or flutter during follow-up, compared to 21.9% (161/735) in patients who remained in sinus rhythm (p<0.0001). In patients with pre-existing atrial fibrillation or flutter, mortality equaled 47.8% (11/23) versus 42.6% (20/47) in patients with atrial fibrillation or flutter manifesting after treatment initiation (p=0.683).
Survival Atrial Fibrillation/Flutter
Conclusion
Atrial fibrillation and flutter are common in patients with curative breast cancer treatment and have a significant impact on overall survival. Our study highlights the impact of cardiac comorbidities on overall survival following cancer treatment and emphasizes the importance of a dedicated cardiac follow-up in cancer survivors.
PCN304 CARDIAC MONITORING AMONG CHEMOTHERAPY,TARGETED THERAPY AND RADIATION THERAPY TREATED BREAST CANCER PATIENTS