Correlation between breast cancer cases missed on mammography and detected on ultrasound, with the histopathological outcomes, in women treated with Hormone Replacement Therapy (HRT)

ABSTRACT Introduction: Breast cancer is one of the most common malignancies in females worldwide. Increased use of Hormone replacement therapy (HRT) for relief of menopausal symptoms has been attributed as one of the many causes of the increasing incidence of breast cancer cases in recent decades. There are certain peculiarities associated with carcinomas caused secondary to HRT use in terms of histological subtypes and issues pertaining to increased non-detection of lesions by mammography in these patients. The objective of this study was to exclusively include patients treated with HRT and also having breast cancer, to evaluate the relationship between cases missed on mammography and detected on Ultrasound with histological subtypes. Methods: A retrospective hospital-based study was conducted using data from women in the age group 40–70 yrs, presenting to the radiology department of a multispecialty hospital over a period of 3 years for mammography. A total of 367 breast cancer cases (5% of total mammograms) fulfilling the inclusion criteria of treatment with HRT were included in the study. Results: The highest proportion of cases was found in the age group 50–60 yrs with an incidence of 47.9%. Overall, the maximum cases detected with cancers were those who had taken prior HRT (81.8%), as compared to those with current HRT intake at 18.2%. The screening cases constituted only 3% of the total positive cases in the study. The breasts with density ‘d’ were among the highest number of cases, numbered 63, that were missed on mammography and consequently detected on ultrasound. Overall, nearly 22.6% of cases were missed on mammography alone and subsequently detected by ultrasound, with Invasive Ductal types constituting the highest share, followed by Invasive Lobular carcinoma. Conclusion: It is recommended that all mammography examinations for either screening or workup for a suspicious palpable nodule must be mandatorily coupled with ultrasound to negate the chances of a false negative diagnosis. This is more relevant in patients treated with HRT, as the breast carcinomas in these patients have a slightly different size, stage, grade, and histological subtype on presentation as compared to the rest of the breast screening cases. Radiological detection is further reduced at mammography due to increased breast density as a result of HRT.