Overview of Cancer and Treatment
Key Clinical Questions
What types of biopsies can aid in the diagnostic workup of cancer?
How is the cancer stage determined?
What are the goals of therapy in the neoadjuvant, adjuvant, and palliative setting?
What are the different types of systemic therapies commonly used in the treatment of cancer?
What are the approaches to treating chemotherapy-related nausea, vomiting and mucositis?
When are modified blood products recommended for cancer patients and what are the transfusion thresholds for anemia and thrombocytopenia?
Cancer is a group of diseases characterized by uncontrolled proliferation of abnormal cells that invade surrounding tissue and carry the potential to metastasize. Environmental and lifestyle risk factors and genetic susceptibility all contribute to an individual’s risk of developing cancer. In 2015, more than 1.6 million Americans will be diagnosed with cancer, and approximately 600,000 cancer-related deaths will occur. The most common cancers afflicting men and women are prostate and breast, respectively, followed by lung and colorectal. Overall, lung cancer is the leading cause of cancer-related mortality, followed by colorectal cancer. The incidence of lung and colon cancer in men is steadily declining, perhaps reflecting decreased tobacco use and emphasis on colorectal cancer screenings. Lung cancer incidence in women is finally starting to decrease after rising over the last few decades, reflecting the delayed uptake in smoking (and later, smoking cessation) by women compared to men.
Biopsy of a primary and/or metastatic site of a presumed malignancy is necessary to provide histologic confirmation of a cancer diagnosis. Involving a hematologist-oncologist early in the workup of a newly diagnosed cancer patient can be helpful in guiding the appropriate testing, biopsy sites, or biopsy techniques. For example, different biopsy techniques—including fine needle aspiration (FNA), core needle biopsy, excisional biopsy, or laparotomy—may be utilized depending on the type of cancer suspected. An FNA alone is inadequate in the diagnosis of lymphomas as the morphology of the nodal tissue is crucial in determining lymphoma subtype. Core needle biopsies and excisional or incisional biopsies provide a larger volume of tissue for pathologic evaluation of morphology and for molecular or genetic analysis. When a hematologic malignancy, such as lymphoma, is suspected, sending a fresh, not fixed, specimen for comprehensive immunophenotyping using flow cytometry is important in yielding the correct diagnosis. Finally, in addition to confirming a cancer diagnosis, the biopsied tissue specimen may guide therapeutic decisions. For example, molecular biomarkers, such as HER2Neu for breast cancer and KRAS/NRAS for colon cancer, have implications for the oncologist’s choice of antineoplastic agents used during therapy.
Accurately staging patients to determine the extent of their disease is critical in determining prognosis and for guiding treatment decisions. Staging often involves radiographic imaging (such as computed tomography [CT] or positron emission tomography [PET] scans) or endoscopic or surgical visualization to determine local and distant organ involvement. Comprehensive ...