Who would be called to assist with cancer treatment?

An oncologist is a medical doctor who specializes in the diagnosis and treatment of cancer. This specialist has extensive training in understanding the complexities of cancer behavior, including various treatment modalities such as chemotherapy, radiation therapy, immunotherapy, and targeted therapies. Oncologists not only focus on treating the disease itself but also play a crucial role in managing the side effects of treatment, providing palliative care, and coordinating with other healthcare professionals to ensure comprehensive care for their patients.

In contrast, while an internist provides primary care and can address a wide range of health issues, their expertise does not extend to specialized cancer treatment. An obstetrician focuses on pregnancy and childbirth, dealing primarily with women's reproductive health rather than cancer. A gerontologist specializes in the care of older adults and may address age-related health issues, but they do not specialize specifically in cancer treatment. Therefore, the oncologist is the most qualified professional to assist with cancer treatment, making this the correct answer.