The impact of patient compliance with adjuvant radiotherapy: a comprehensive cohort study.

Postoperative radiotherapy (RT) is the standard of care for early stage breast cancer. It reduces the risk for local recurrence and prolongs survival. We assessed whether, the omission of RT because of patient's preference may influence the prognosis and, thus, the quality of cancer care. Detailed information from a prospectively collected database of a breast cancer center was analyzed. Multiple regression analysis and univariate and multivariate analysis for risk factors for recurrence were performed. The entire cohort of primary breast cancer patients in a given time period was analyzed. Data from 1903 patients undergoing treatment at breast cancer center between 2003 and 2008 were used. All patient underwent breast conserving surgery and RT was performed for all patients of the cohort. Local tumor control and disease-free survival were calculated. After a median follow-up of 2.18 years (maximum 6.39 years), 5.5% of patients did not follow guideline-based recommendations for RT. There was a significant correlation between noncompliance and patient's age, adjuvant hormonal therapy (97.0%), and adjuvant chemotherapy (96.8%). Seventy local recurrences occurred that corresponds to a local recurrence rate of 3.9%. The difference in regard to local recurrence-free 5-year survival between the compliant patients and the noncompliant patients is absolute 17.9 (93.3% and 75.4%). Noncompliant patients had suffered a 5.02-fold increased risk of local recurrence than compliant patients. The omission of RT after breast-conserving surgery results in a higher local failure rate and significantly worsens clinical outcome. Age may play an important role because of the comorbidities of aged patients or the assumed low RT tolerance in this group. On a clinical level, this data suggests that improvement is needed to correct this situation, and the question remains as to how best to improve RT compliance.