Cancer Morbidity and Mortality

Targeted therapy exerts antineoplastic activity against cancer cells by interfering with unique properties found in tumors or malignancies. The types of drugs can be small molecules, which are able to enter cells, or monoclonal antibodies, which have targets outside of or on the surface of cells. Among the areas in malignant cells that are blocked or inhibited by targeted therapy are signal pathways (as seen in protein kinase inhibitors), which lead to decreased proliferation and subsequent tumor cell apoptosis. Other means of reducing cancer cells is by eliminating the capacity for DNA repair (seen in poly(ADP-ribose) polymerase inhibitors), blocking the ligand-receptor binding (growth factor inhibitors), and increasing immune activity against the neoplasm (immunotherapies). These agents are used in multiple types of cancer and in combination with traditional chemotherapeutic agents.

Paraneoplastic syndromes are a heterogeneous group of disorders caused by an abnormal immune response to a neoplasm. The substances produced are not due to the direct effect of the tumor, such as metastasis, mass effect, or invasion. Antibodies, hormones, cytokines, and other substances are generated and affect multiple organ systems. About 10% of cases of cancer are affected by paraneoplastic syndromes. The common cancers that present with paraneoplastic syndromes include cancer of the lung, breast, ovaries, kidney, liver, and stomach and lymphomas.

Neutropenic fever is a medical emergency defined as a fever > 38.3℃ (100.9℉) or higher than 38.0℃ (100.4℉) for more than 1 hour in neutropenic patients. Neutropenic fever is a common life-threatening complication of hematologic malignancies and in patients undergoing chemotherapy. Patients are often asymptomatic, and the only sign is the presence of fever. Diagnosis should include a detailed history, physical examination, and routine laboratory tests, in addition to symptom-directed workup with cultures. Initial management includes the administration of empiric antibiotics adjusted according to clinical response and culture results.

Carcinoid tumors are small, well-differentiated, slow-growing neuroendocrine tumors (NET). Carcinoid syndrome describes the signs and symptoms associated with unregulated vasoactive hormone production by neuroendocrine tumors. Carcinoid tumors are most commonly found in the GI and bronchopulmonary tracts. Vasoactive substances produced by NET of the GI tract do not cause carcinoid syndrome until the tumors metastasize to the liver. Symptoms of carcinoid syndrome include flushing, diarrhea, and wheezing. Treatment consists primarily of surgical tumor resection and therapy with somatostatin analogs. Prognosis depends on the tumor location, aggressiveness, and overall disease burden.