Conditional Disease-Free and Overall Survival of 1,858 Young Women with Non-Metastatic Breast Cancer and with Participation in a Post-Therapeutic Rehab Programme according to Clinical Subtypes

Abstract

<b><i>Background:</i></b> Breast cancer in young women is associated with unfavourable tumour biology and is the main cause of death in this group. Conditional survival analysis estimates survival rates under the pre-condition of already having survived a certain time. <b><i>Objectives:</i></b> To describe conditional disease-free and overall survival of female breast cancer patients according to clinical subtypes and age. <b><i>Methods:</i></b> This study analyses information from 1,858 breast cancer patients aged between 21 and 54 years, who were taking part in a post-therapeutic rehab programme (time between diagnosis and rehab start: maximum 24, median 11 months). Mean follow-up time was 3.6 years. We describe biological, clinical and pathological features in regard to different age groups (&#x3c;40 and ≥40 years) and report conditional 5-year survival rates for overall and disease-free survival, and Cox proportional hazard models. <b><i>Results:</i></b> Very young and young patients differed in regard to hormone receptor negativity, tumour grade, lymphovascular invasion, and molecular subtypes. Young women bore triple-negative and HER2-like disease more frequently. Conditional 5-year overall survival did not differ substantially between women &#x3c;40 and 40–54 years of age (95 vs. 96%). It was highest for women with cancer of the luminal A subtype (98%) and lowest for the triple-negative subtype (91%). Lymphangiosis was a significant predictor of death. Results for disease-free survival were comparable. <b><i>Conclusions:</i></b> Conditional 5-year overall survival after non-metastatic breast cancer was as high as 95.5%, and disease-free survival was 85.2%. When controlling for time between diagnosis and rehab start, molecular subtypes influenced overall and disease-free survival prospects. When additionally controlling for clinical characteristics, this effect only remained stable for disease-free survival.