Impact of full-field digital mammography on pre-operative diagnosis and surgical treatment of mammographic microcalcification

Abstract

Accurate pre-operative diagnosis of impalpable breast lesions correlates closely with the number of surgical procedures required for treatment. Correct diagnosis of mammographic microcalcification (MM) as ductal carcinoma in situ (DCIS) or invasive breast cancer is important because lesions upgraded to malignant diagnosis at surgery require repeat surgical procedures in 44% of cases. Despite correct pre-operative diagnosis of MM, 26% require second therapeutic operations to achieve surgical clearance. Theoretically, improved conspicuity of malignant MM using digital mammography could improve diagnostic work-up and improve surgical outcomes for MM. To determine the impact of full-field digital mammography (FFDM) on the diagnostic accuracy and positive predictive value (PPV) of biopsy of MM and surgical management of MM, screening and symptomatic cases with MM (n=1,479) were reviewed for women imaged between August 2007 and March 2010 using screen-film mammography (SFM) (n=711), and using FFDM, imaged between April 2010 to March 2012 (n=768). Demographic information including pre and postoperative diagnosis, and number and types of surgical procedures were recorded. Overall, 302 (128 invasive) and 251 (110 invasive) malignant lesions were diagnosed using SFM and FFDM, respectively. Reduction in PPV of biopsy was observed (SFM 42.5%; FFDM 32.7%, p<0.001). Correct pre-operative diagnosis was achieved at first attempt more often with FFDM (SFM 80.6%; FFDM 89.5%, p<0.001). For lesions with pre-operative diagnosis, B5 more cases achieved surgical clearance with a single therapeutic operation with FFDM (SFM 66.3%; FFDM 76.7%, p=0.017), and more lesions over 2cm underwent mastectomy as the initial surgical procedure (SFM 47.0%; FFDM 62.9%, p=0.005). Correct pre-operative diagnosis of MM using digital mammography reduced second therapeutic operations but increased mastectomy rate in larger cancers over two centimetres. This will increase concerns about treatment of lesions detected in the screening programme with widespread use of digital mammography.