Pathologic findings from the Breast Cancer Surveillance Consortium: population-based outcomes in women undergoing biopsy after screening mammography.
BACKGROUND
To the authors' knowledge, a comprehensive analysis of pathology outcomes after screening mammography, as it is practiced clinically in the U.S. general population, has not been performed.


METHODS
Breast Cancer Surveillance Consortium data from 1996-2001 were used to identify pathology specimens that were obtained within 1 year of screening mammograms performed on 786,846 women ages 40-89 years. The pathology results were classified as invasive carcinoma, ductal carcinoma in situ (DCIS), or benign. The associations between overall pathology outcomes and invasive tumor size and lymph node status were analyzed by age and mammography assessment category.


RESULTS
The rates of both recommending and performing a biopsy varied little with age. The 1,664,032 screening mammograms were followed by 26,748 known biopsies (1.6%) and 8815 diagnoses of breast carcinoma (0.53%). Overall, 81% of carcinomas were invasive, and 78% of those were pathologically lymph node-negative tumors, in contrast to the 66% prevalence observed in the Surveillance, Epidemiology, and End Results (SEER) data during the same period. Most invasive tumors measured between 0 mm and 10 mm (35%) or between 11 mm and 20 mm (36%) in greatest dimension, and 92% and 78% were lymph node-negative tumors, respectively: Biopsy results that were classified as malignant increased with age (P < 0.0001) and were most likely to follow Breast Imaging, Reporting, and Diagnosis System Category 5 and 4 assessments, respectively. Ductal hyperplasia (19.6%), fibroadenoma (18.5%), and other benign findings (56.1%) were the most common benign diagnoses.


CONCLUSIONS
Pathologically negative lymph nodes were more prevalent in this mammographically screened population than in the overall SEER population. The prevalence of invasive carcinoma, DCIS, and benign findings presented herein establish a range of expected biopsy outcomes for women after screening mammography in the general U.S. population.
Weaver
Donald L
DL
Department of Pathology, University of Vermont, Burlington, 05405, USA. donald.weaver@uvm.edu
Rosenberg
Robert D
RD
Barlow
William E
WE
Ichikawa
Laura
L
Carney
Patricia A
PA
Kerlikowske
Karla
K
Buist
Diana S M
DS
Geller
Berta M
BM
Key
Charles R
CR
Maygarden
Susan J
SJ
Ballard-Barbash
Rachel
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D015995:Prevalence; D018426:SEER Program / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology