A 48-year-old woman is evaluated for a painless left breast mass. Physical examination shows a 4-cm mass with dimpling of the overlying skin; left axillary lymphadenopathy also is noted. Breast imaging reveals a spiculated soft tissue mass with microcalcifications. Biopsy of the mass demonstrates invasive ductal carcinoma. Immunohistochemistry of the tissue sample shows the tumor cells are negative for estrogen and progesterone receptors but overexpress the HER2 epidermal growth factor receptor. The patient is treated with systemic chemotherapy and a monoclonal antibody drug that binds the extracellular domain of the growth factor receptor. Repeat evaluation 6 weeks later shows a decrease in the size of the breast mass. Which of the following host factors are primarily responsible for mediating the response to the monoclonal antibody therapy?

Question

A 48-year-old woman is evaluated for a painless left breast mass.  Physical examination shows a 4-cm mass with dimpling of the overlying skin; left axillary lymphadenopathy also is noted.  Breast imaging reveals a spiculated soft tissue mass with microcalcifications.  Biopsy of the mass demonstrates invasive ductal carcinoma.  Immunohistochemistry of the tissue sample shows the tumor cells are negative for estrogen and progesterone receptors but overexpress the HER2 epidermal growth factor receptor.  The patient is treated with systemic chemotherapy and a monoclonal antibody drug that binds the extracellular domain of the growth factor receptor.  Repeat evaluation 6 weeks later shows a decrease in the size of the breast mass.  Which of the following host factors are primarily responsible for mediating the response to the monoclonal antibody therapy?

Quizplus · Accepted Answer

Eductional Objective: Cancer immunotherapy often includes the administration of monoclonal antibodies against a target overexpressed on the cancer cell surface.  The Fc portion of the bound antibody is identified by natural killer cells via CD16, leading to antibody-dependent cellular cytotoxicity via the release of granzymes and perforin.

A 48-Year-Old Woman Is Evaluated for a Painless Left Breast