American Board of Internal Medicine (ABIM) Certification Practice Exam

What is indicated for patients with newly diagnosed metastatic gastric cancer?

1. CT scan of abdomen

2. HER2 tumor status determination

3. Bone marrow biopsy

4. Endoscopy

The correct answer is: HER2 tumor status determination

For patients with newly diagnosed metastatic gastric cancer, determining the HER2 tumor status is essential for guiding treatment options. HER2 is a protein that can promote the growth of cancer cells, and testing for this status can identify patients who are likely to benefit from HER2-targeted therapies, such as trastuzumab. This has been shown to improve outcomes for patients whose tumors overexpress the HER2 protein. In newly diagnosed metastatic gastric cancer, the other options, while they may provide useful information, do not have the same direct impact on treatment planning. A CT scan of the abdomen can help assess the extent of disease and the presence of metastases but does not directly influence the choice of systemic therapy. A bone marrow biopsy is typically not indicated in the diagnosis or management of metastatic gastric cancer unless there is specific suspicion of hematologic involvement. Endoscopy may be used for direct visualization or for obtaining biopsies, yet it does not provide the targeted treatment information that HER2 status determination does. Hence, testing for HER2 is crucial for personalized management of metastatic gastric cancer.