Improved Prognosis of Women Aged 75 and Older with Mammography-detected Breast Cancer

Abstract

To evaluate the characteristics and outcomes of women aged 75 years and older with mammography-detected breast cancer, an age group not represented in mammography screening effectiveness studies. We conducted a HIPAA-compliant, prospective cohort study with waiver of informed consent in patients with primary breast cancer, aged 75 years and older, with stage 0-IV disease from 1990 to 2011, identified and tracked with our registry database (n = 1162). Details including stage, treatment, outcomes, and method of detection (by patient, physician, or mammography) were noted from the chart at the time of diagnosis. Kaplan-Meier estimation was used to compare invasive disease-specific survival rates. Among patients with breast cancer aged 75 years and older, mammography detection of cancers increased over time, from 49% to 70% (P < .001). Mammography-detected cases were more often stage I (62%), whereas patient- and physician-detected cases were more likely stage II and III (59%). Over time, from 1990 to 2011, the incidence of stage II cancers decreased by 8%, the incidence of stage III cancers decreased by 8%, and the incidence of stage 0 cancers increased by 15% (P < .001). Patients with mammography-detected invasive breast cancer were more often treated with lumpectomy and radiation and underwent fewer mastectomies and less chemotherapy than patients with cancer detected by patients and physicians (P < .001). Mammography detection was associated with significantly better 5-year disease-specific survival for invasive breast cancer (97% vs 87% for patient- and physician-detected cancer [P < .001], respectively). Mammography-detected breast cancer in women 75 years and older was diagnosed at an earlier stage, required less treatment, and had better disease-specific survival than patient- or physician-detected breast cancer. These findings indicate that the same benefits of mammography detection observed in younger women extend to older women.