Prognostic significance of mammographic detection in a cohort of conservatively treated breast cancer patients.
Academic Article
Overview
abstract
PURPOSE: This study aimed to evaluate the prognostic significance of nonpalpable mammographically detected breast cancer in a cohort of conservatively treated breast cancer patients. METHODS AND MATERIALS: The records of 953 patients with invasive stage I and II breast cancer treated with conservative surgery and radiation therapy prior to January 1990 were reviewed. Mode of presentation with reference to clinical and mammographic findings was recorded. For statistical analysis, patients were divided into two groups: 748 patients presented with clinically palpable masses with or without mammographic abnormalities (PALP), and 205 presented with nonpalpable mammographically detected tumors (MGDET). RESULTS: Patients in the MGDET group presented with cancers at earlier stages of disease, had tumors of smaller pathological size, were more often hormone-receptor positive, and less frequently required adjuvant systemic therapy. As of December 1995, with a median follow-up of 11.6 years, the MGDET group had a higher 10-year overall survival rate (82% vs 68%) and a superior 10-year distant-metastasis-free rate (87% vs 75%). The ipsilateral breast tumor relapse rate was similar between the PALP and MGDET groups. When broken down by age (< 50 years vs > or = 50 years), the benefits of early detection remained apparent with a statistically significant superior distant-metastasis-free rate in women under age 50 in the MGDET group compared with women under age 50 in the PALP group. In a multivariate analysis, mammographic detection remained an independent prognostic factor for distant-metastasis-free survival. CONCLUSION: Patients presenting with nonpalpable mammographically detected invasive breast cancer have a favorable prognosis compared with their counterparts presenting with clinically palpable masses. Although the issue of lead-time bias cannot be addressed adequately in this retrospective review, the favorable prognosis with respect to disease-free survival and breast conservation is quite evident. The high probability of disease-free survival and breast preservation in these patients should further encourage the widespread using of screening mammography and the increased use of breast-conserving surgery with radiation therapy.
