Resident Physician UPMC Community General UPMC Community Osteopathic Harrisburg, PA, United States
Introduction/Purpose: Pregnancy associated breast cancer (PABC) is becoming increasingly more common due to changes in society as women in delay having children to later in life. The difficulty of diagnosing PABC is a result of the changes of the breast within pregnancy and in lactation, altering the structure of the breast and making standard imaging less effective or unsafe. Our study looks at three postpartum mothers with recent diagnosis of breast cancer, all lactating, that show the milk rejection sign from their babies leading them to seek medical advice.
Methods or Case Description: 3 postpartum mothers with new diagnoses of breast cancer in the postpartum period were investigated for this case study. 2 of the 3 mothers noted preferential breast feeding of the newborn on the contralateral side of positive breast cancer. The other mother did not breast feed, but rather pumped during the post partum period. Breast cancer diagnoses of all three patients were invasive ductal cancer, with only one patient having additional high grade DCIS microinvasion on pathology. Patients were all treated with surgical excision.
Outcomes: When diagnosed with PABC, cancer is noted to be more aggressive and more advanced stages compared to nonpregnant females [1]. A higher risk of death was also noted when controlled for stage and hormone receptor status [2]. Theories to the advanced stage at diagnosis include limited therapy due to possibly affecting fetal development, bodily changes during pregnancy and diagnostic limitations [1]. Our case study had 3 postpartum mothers with confirmed invasive carcinoma requiring subsequent excision and chemoradiation in some cases. The use of different diagnostic modalities like ultrasound, MRI and mammogram, and their combination, are still being discussed when it comes to diagnosing PABC. There is no definite treatment algorithm to properly diagnose PABC at this time.
Conclusion: As a standard of care, ultrasound is the initial diagnostic modality for women between 30 and 40, but with the density of the breast in pregnancy, this study is can be limited. A study completed by Chung et al. noted a 3% malignancy rate and out of those with diagnosed cancer, 4 out of 5 had axillary metastasis, leading their study to have a 100% sensitivity of detecting cancer [24]. In previous studies, mammography was noted to be between 78 and 90% sensitive and those not detected by mammography due to the density of the breast were successfully identified with US [25]. None of the women in the study done by Chung had ductal carcinoma in situ, which all three of our patients had [24]. US features like calcification, asymmetric density, axillary lymphadenopathy, and skin and trabecular thickening were key in helping to diagnose PABC [26]. At this point, MRI is not recommended for diagnosis of PABC in pregnant females due to the classification of contrast as a category C by the USFDA [27]. MRI for lactating females is still difficult to due to increased enhancement from hypervascularity [27]. There are some studies, like those done by Yang et al. that suggest a complimentary use of US and mammography to diagnose PABC, especially with invasive or in situ cancers [25].
PABC reported among women during pregnancy or within 2 years of postpartum. Clinical suspicion should raise awareness for both patient and provider and should prompt further investigation.
