Routine use of both mammography and MRI surveillance in patients with previous 'mammogram occult' breast cancer: experience from a tertiary centre.

Abstract

To evaluate the role of combined MRI and mammogram follow-up in patients with previous 'mammographically occult' breast cancer. Between 2011 and 2016, examinations of all patients undergoing routine surveillance following previous 'mammogram occult' breast cancer were evaluated. Patients had both MRI and mammograms on the same day with an interval of 12-18 months between consecutive pairs. Total number of recalls on both imaging modalities and the outcome of those recalls was recorded. There were six median examinations per patient. There were a total of 325 examinations of 54 patients. There were 96 mammograms/MRI pairs and 87 lone MRI and 46 lone mammograms. There were a total of 26 recalls in 21 patients. MRI had specificity (95% CI) of 89.99 (85.67 to 93.11) compared to mammograms 96.27 (92.53 to 98.25). The diagnostic OR with 95% CI was 19.40 (3.70 to 101.57) vs 6.72 (1.43 to 31.58) of mammograms and MRI, respectively. Three of seven cancers presented symptomatically. MRI surveillance leads to higher recalls and false positives compared to mammograms in this specific subgroup of high-risk patients. Large proportion of cancers presented symptomatically, stressing the importance of remaining vigilant of breast symptoms despite imaging surveillance.