Can someone help me please?

Question

A 45 year-old woman complaining of breast pain was diagnosed with having HER2-positive breast cancer. The patient underwent lumpectomy followed by a period of chemotherapy including adjuvant treatment. Over the course of their treatment, the patient developed a urinary tract infection that required antimicrobial therapy, which initially consisted of a trimethoprim/sulfametoxazole combination drug. However, the patient during the course of her therapy suffered multiple recurrent infections and was, consequently, enrolled in a clinical trial to test the efficacy of a new mannoside anti-infective agent.

Question: Discuss the mechanisms underpinning current therapeutic strategies for treating HER2-positive breast cancer. In your discussion, you should include details about managing therapeutic resistance and adverse side effects such as cardiotoxicity.

Answer 1

It is essential that all patients with newly diagnosed breast cancer be tested for human epidermal growth factor receptor 2 (HER2) overexpression because HER2-directed therapy is a critical component of the adjuvant treatment of HER2-positive breast cancer.

For most patients with HER2-positive, node-negative tumours>2 cm in size or node-positive tumours, in addition to trastuzumab, either dose-dense doxorubicin and cyclophosphamide followed by paclitaxel.

Previous or concurrent anthracycline use and age greater than 50 years are the strongest risk factors for the development of trastuzumab-related cardiotoxicity.

Baseline assessment prior to starting trastuzumab and serial LVEF monitoring (at 3, 6, and 12 months after initiating trastuzumab.

If the LVEF declines 16 or more percentage points from baseline, trastuzumab is withheld for four weeks, at which time the LVEF is reassessed.

If the patient has symptomatic heart failure on therapy, trastuzumab should be discontinued.