Breast Cancer Clinical Case Review

Mridula George, MD, assistant professor of medicine at Rutgers Robert Wood Johnson Medical School, and associate program director for breast medical oncology program in the division of medical oncology at Rutgers Cancer Institute of New Jersey, presents the baseline characteristics of the case.

Editor’s note: The following is an automatically generated transcript of the above video.

"The patient is a 58 year old post-menopausal woman with a past medical history of hypertension and hyperlipidemia. She presents to her primary physician for a routine exam. She is in good state of health, does not have any new symptoms, and she gets an annual blood work as part of her routine physical exam. And the blood work is concerning for an abnormal liver function test.

Based on these lab results, a liver ultrasound is ordered for further evaluation which shows multiple hepatic masses, which is concerning for a malignant process. Based on this ultrasound, patient has a liver biopsy which confirms metastatic disease. The immunohistochemical stains for CK7 and GATA-3 are positive, which confirms an adenocarcinoma of breast primary. The other stains that were checked were CK20, CDX-2, TTF-1 and CA19.9, which were negative, which confirms lung or GI primary.

The other biomarkers that were checked, given that it's a breast primary, where the estrogen receptor, which was positive at 100% expression. The progesterone receptor was negative and the HER2 was positive by immunohistochemistry 3+. HER2 is expressed in about 20 to 25% of breast cancer and is characterized by an aggressive growth and poor prognosis.

So in this patient, given this diagnosis, we need to do additional work up. On obtaining more history, we find out that patient has not had a screening mammogram in over 10 years, and on physical exam, she has a palpable right breast mass by the inframammary fold. Patient had not been aware of this breast mass given the location of the mass. So baseline staging scans are ordered. A CT chest, abdomen, and pelvis was ordered, which showed a 5.2 by 4.5 centimeter right breast lesion. And there were several enlarged right axillary lymph nodes.

Besides the breast mass and the axillary lymph nodes, there are hepatic masses involving both lobes of the liver. The largest is in the right hepatic lobe measuring five centimeters, and the second largest mass was about three centimeters. A bone scan was obtained to determine if there were any bone metastases and there was no evidence of any osseous metastases.

So things to consider when someone is diagnosed with metastatic breast cancer, an important thing is genetic testing to assess for a germline BRCA 1 and 2 mutation. And this is important because we have a class of drugs, specifically PARP inhibitors that are approved for the treatment of breast cancers in patients who have germline BRCA 1 and 2 mutation. On the two PARP inhibitors that are approved are Olaparib and Talazoparib. However, the FDA indications only for HER2 negative disease. But the NCCN guidelines supports the use in any breast cancer subtype of patients who have a germline mutation. This is a lower level evidence for HER2 positive breast cancer as a category 2A evidence. But it's important to do the genetic testing in patients who are diagnosed with breast cancer.

Another important testing that should be considered in patients diagnosed with HER2 positive metastatic breast cancer is MRI of the brain. Breast cancer is the second most common cause of brain metastases and the incidences vary from 10 to 30%. And among the various subtypes, HER2 positive breast cancer as well as triple negative breast cancer has the highest incidence of brain metastasis. And in the HER2 positive subtype, the incidence of brain metastasis varies anywhere from 25% to 50% depending on which report you're looking at. So it is strongly encouraged to get an MRI brain as a baseline and does not have to be repeated as long as patient does not have any neurological symptoms.

And another important thing to consider is an echocardiogram. Patients with HER2 positive breast cancers are treated with HER2 targeted therapies and it increases the risk of LV dysfunction. In the initial study by Slamon and Colleagues, which evaluated Trastuzumab with Anthracycline, symptoms of heart failure was up to 27% in HER2 positive breast cancer compared to 7% in the Anthracycline only arms. So it's very important to consider this in patients diagnosed with metastatic HER2 positive breast cancer."