Breast cancer recurrence in older women five to ten years after diagnosis.

Little is known about the risk of recurrence >5 years after diagnosis among older breast cancer survivors. A community-based population of women >or=65 years diagnosed with early-stage breast cancer who survived disease free for 5 years was followed for 5 additional years or until a diagnosis of breast cancer recurrence, second primary, death, or loss to follow-up. These 5-year disease-free survivors (N = 1,277) had primary breast cancers that were node negative (77%) and estrogen receptor positive or unknown (86%). Five percent (n = 61) developed a recurrence between 5 and 10 years after diagnosis: 25% local, 9.8% regional, and 66% distant. Women who were node positive [hazard ratio (HR), 3.9; 95% confidence interval (95% CI), 1.5-10], had poorly differentiated tumors (HR, 2.5; 95% CI, 0.9-6.6), or who received breast conserving surgery without radiation therapy (HR, 2.4; 95% CI, 1.0-5.8) had higher recurrence rates compared with node negative, well differentiated, and receipt of mastectomy, respectively. Not receiving adjuvant tamoxifen, compared with receiving adjuvant tamoxifen, was also positively associated with late recurrence among women with estrogen receptor-positive/unknown tumors. Although relatively few women experience a late recurrence, most recurrences present as advanced disease, which is difficult to treat in older women. This study of late recurrence emphasizes that the risk, although small, is not negligible even in this group at high risk of death due to competing causes.