ABSTRACT
BACKGROUND: Breast cancer screening has been shown to reduce breast cancer-associated mortality. However, screening is limited to the targeted age group of 45 to 69 years in New Zealand despite the recognized increased risk with age. This study aims to compare the outcomes of women aged over 70 years with screen-detected and clinically detected cancers. PATIENTS AND METHODS: A retrospective review was performed of prospectively collected data from June 2000 to May 2013 by the Auckland Breast Cancer Register. Demographic and tumor characteristics of women with invasive cancer and ductal carcinoma in situ diagnosis aged 70 years and over were compared between those screened and clinically detected. Five-year disease-free and overall survival outcomes were reviewed. RESULTS: A total of 2128 women aged 70 years and over were diagnosed with breast cancer (median, 77 years; interquartile range [IQR], 74-84 years). Of these, 416 (19.5%) were diagnosed through mammography screening, with a median age of 74 years (IQR, 71-77 years) compared with 79 years (IQR, 74-85 years) for those with clinical detected cancer diagnosis. Screen-detected cancers accounted for a significantly higher proportion of diagnoses in those aged 70 to 74 years compared with older patients (P < .001). Screen-detected cancers were of lower T and N stages. Disease-specific survival was significantly longer in screen-detected cancers versus other cancers (5-year survival, 93.7% vs. 81.9%; P < .001), as was overall survival (5-year survival, 84.7% vs. 57.4%; P < .001). CONCLUSION: Screening in those aged 70 years and over continues to identify breast cancer at early stages and with improved survival. Although aware of the potential for lead-time bias and the healthy volunteer effect, there should still be consideration to extend breast cancer screening to patients aged to up 74 years after appropriate assessment of comorbidities and functional status.
