Breast Cancer- Retrospective review of imaging findings and surveillance outcomes after oncoplastic breast conserving surgery 

Leong CH Lester

Effectiveness of mammogram surveillance in patients with previous history of mammographically occult breast cancer 

Abstract Disclosures

Abstract
Background: Approximately 10-20% of breast cancer patients treated with breast conserving surgery develop local recurrence while the risk of contralateral breast cancer is 0.5% per year. Mammogram is the main imaging surveillance modality after treatment of initial disease and is associated with improved survival. However, if the initial primary breast cancer is mammographically occult, there may be a higher possibility that the local recurrence or subsequent metachronous breast cancers are also mammographically occult, thereby rendering mammogram surveillance ineffective. In which case, imaging modalities other than mammography should be considered for the surveillance of breast cancer recurrence. The aim of the study is to investigate if patients with a mammographically occult breast cancer are more likely to develop second breast cancers that are also mammographically occult. There is a lack of data examining the effectiveness of mammographic surveillance in patients with mammographically occult primary breast cancers. Dershaw et al in 1992 found that invasive lobular carcinomas recurrence are more likely to be mammographically occult. Weinstock et at in 2012 found that younger women and those who self-detected their first cancers were more likely to self-detect their second cancers during the surveillance period. However, these papers do not specifically assess if a mammographically occult breast cancer is a risk factor for having mammographically occult second breast cancer. 

Method: This is retrospective study of patients who were diagnosed with breast cancer recurrence or second metachronous breast cancers between 2006-2015. Dedicated breast radiologist will review the mammograms on picture archiving and communication system (PACS) to determine if the first and subsequent presenting breast cancers were mammographically detectable or occult. The number of mammographically occult second breast cancers will be compared between 2 cohorts of patients whose first breast cancers are mammographically occult vs mammographically detectable.

Joint Breast Cancer Registry Singapore