Method of detection is a prognostic factor for outcome among women diagnosed with early stage breast cancer.

Abstract

Abstract Abstract #5005 Background: The reduction in breast cancer mortality over the past several decades has been partially attributed to the impact of screening mammograms. Breast cancers detected by screening mammograms tend to be at an earlier stage than those detected as a result of symptoms. The magnitude of the impact of method of detection on breast cancer survival beyond this phenomenon, known as stage shift, is not well defined. We therefore evaluated the independent prognostic effect of method of detection among women diagnosed in early stages of disease (stage I and II breast cancers). Methods: Medical records from 2,143 women aged 40 or older with stage I and II breast cancers, treated at the M.D. Anderson Cancer Center between 1985 and 2000 were used to derive information on method of breast cancer detection, clinical and histological tumor characteristics. Cox proportional hazards models were used to estimate the hazard ratios (HR) of breast cancer recurrence and breast cancer-specific death adjusted for age at diagnosis, year of diagnosis, nuclear grade, hormone receptor status, systemic treatment and stage at diagnosis. All statistical tests were two-sided. Results: Patients ages 40-49, 50-69 and ≥70 with symptom compared to screen-detected breast cancers were statistically significantly more likely to be diagnosed with stage II versus stage I disease and were more likely to have higher nuclear grade III versus grade I tumors. Symptom-detected breast cancers were associated with an increased risk of breast cancer recurrence (HR 1.9, 95% confidence interval (CI) 1.4-2.6) and breast cancer-specific death (HR 2.0, 95% CI 1.4-3.0) than screen-detected breast cancers after adjusting for age at diagnosis, year of diagnosis, tumor size, lymph node involvement, tumor characteristics and systemic treatment. Discussion: Our data from a large cohort of breast cancer patients with long-term follow-up indicate that even among patients with early stage disease; those with symptom-detected breast cancers have a worse prognosis. Consideration should be given to including method of detection as a prognostic factor when making treatment decisions for patients with stage I and II breast cancers. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5005.