Abstract P6-03-02: Breast Reduction Mammoplasty and Incidence of Occult Carcinoma. A 10 Year Experience

Background: The aim of this study was to report the incidence of cancer in reduction mammoplasty specimens and suggest alternative pragmatic cost-effective way of identifying and treating patients with carcinoma. Methods: All patients who underwent breast reduction surgery at Northern General Hospital over a 10-year period were identified from a prospective database. The histopathology reports and case records of all patients with significant abnormalities were analysed. All breast reduction specimens were sliced at 1 cm intervals and examined macroscopically. At least 3 blocks per breast were examined microscopically in addition to sampling of any grossly abnormal tissue. Results: Between October 1999 and April 2010, 1,588 patients underwent reduction mammoplasty. The median age of patients was 38 years (range 16-75 years). Indications for surgery were macromastia in 1,194 (75.2%), congenital asymmetry in 182 (11.5%) and contralateral symmetry procedure post breast cancer surgery in 178 (11.2%). 9 specimens showed atypical hyperplasia (0.57%). 5 cancers were detected (0.31%). 4 of the 5 patients had normal mammograms 1-3 years before the reduction operation (not done in 1). Of these cancers, 4 were invasive (3 invasive lobular, 1 invasive ductal) (0.25%) (mean invasive tumour size 9 mm (SD 7.4)) and 1 was DCIS (4mm) (0.06%). A lump was felt macroscopically by the pathologist in 2 of the 4 patients with invasive cancer. The median age of patients with invasive cancer was 56 years (range 47-68 years). Patient found to have DCIS did not undergo further surgery while those with invasive disease underwent mastectomy (3) and axillary nodal staging (4). None of the patients with benign/normal post-reduction breast imaging had residual breast cancer on histology. Conclusion: The incidence of occult carcinoma in reduction mammoplasty specimens is less than 0.5%. Pre-operative mammogram is not useful as 4 of the 5 patients with cancer had a normal mammogram 1-3 years before surgery and invasive lobular cancers are often not detected on mammogram. Mastectomy may be avoided in patients with no residual breast disease on post-reduction imaging. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-03-02.