Cancer Study Quiz

Neoplastic Disease: Cancer

• Cancer is not a single disorder, but rather over 100 different disease types.
• Cancer differs in characteristics, body locations, and treatment requirements.
• Cancer is a disorder of cell growth and regulation, with abnormal cells dividing uncontrollably and invading other tissues.
• It is the second leading cause of mortality in the US (first is cardiovascular disease).

Phases of Carcinogenesis

• Carcinogenesis is a multistage process occurring in three phases: initiation, promotion, and tumor progression (including metastasis).
• A carcinogen is a physical, chemical, or viral agent that induces cancer.
• Initiation involves the interaction of chemicals, radiation or viruses with cellular DNA, transforming normal cells. This process is rapid but cells may remain dormant for a variable period.
• Promotion involves cancer cells multiplying and evading mechanisms meant to protect against growth and the spread of the cells.
• Tumor progression involves the aggregation and growth of cells into a malignant neoplasm. Metastasis is the invasion and spread to distant tissues/organs. This requires the tumor to develop its own blood supply.

Signs and Symptoms of Cancer

• Unexplained weight loss of 10 or more pounds may be an initial sign.
• Fever is common in cancer cases and can occur after the cancer has spread.
• Fatigue is a common symptom, potentially occurring early or later in the course of the disease.
• Pain is commonly associated with the spread of cancer (metastasis).
• Skin changes (such as darker, yellowish or reddened skin) and excessive hair growth are potential associated symptoms.
• Constitutional symptoms of cancer may include anorexia, fatigue, weight loss, fever, sweating, and anemia.
• Metastatic symptoms include pain, enlarged lymph nodes, cough, bone pain, and neurological symptoms.

Etiology of Cancer

• Cancer etiology is multifactorial, involving genetic, environmental, and lifestyle factors that lead to genetic and epigenetic changes.
• Potential risk factors are growing older, tobacco use, sunlight/ionizing radiation exposure, certain chemicals, some viruses/bacteria and hormones, family history of cancer, alcohol, poor diet, lack of physical activity, and being overweight.
• Carcinogens (like chemicals, physical agents such as UV radiation, and viral/bacterial agents) can contribute.
• Major gene categories influencing cancer include oncogenes (which promote tumor growth and change apoptosis) and tumor-suppressor genes (affecting cell death).
• Epigenetics involves changes in gene activity without altering the DNA itself, often from chromatin (DNA and protein) modifications.

Cancer and Nutrition: Nutritional Risk and Preventing Factors

• Heavy consumption of red/processed meats (including processed meats) increases cancer risk for a range of cancer types.
• Cancer development can be suppressed by diets with lower protein levels compared to optimally required amounts, although higher levels tend to enhance development.
• Food preparation methods (like smoking, salting, or pickling) can produce carcinogens, as can high-temperature cooking of meats (producing PAHs and HCAs).
• Diets high in saturated fats or certain types of fat, alcohol consumption and obesity are also risk factors.
• On the other hand, diets high in fruits, vegetables, antioxidants (e.g vitamin C, A, E, selenium, zinc), whole grains, fiber, vitamin D, coffee, tea (with antioxidants), folate, and soy may have protective effects against cancer development.

Cancer Pathophysiology

• Cancer is characterized by: unregulated cell growth, tissue invasion, and metastasis (spread to nearby or distant areas).
• A neoplasm is benign when growth occurs without tissue invasion.
• A malignant neoplasm has the potential to spread to other tissues and organs - through the lymphatic system, circulatory system, or nearby body cavities.
• Cancer is characterized by further abnormal phenotypes like failure to differentiate, loss of apoptosis and genetic instability due to mutations, increased angiogenesis, and evasion of the immune system.

Medical Diagnosis

• Diagnostic procedures include: blood and physical tests, cytologic tests, imaging, and biochemical analysis of body fluids to detect biomarkers.
• Tumors are classified based on size, location and spread (using the TNM system, describing primary tumor, lymph nodes, and metastases).

Cancer Treatment

• Treatment modalities vary, including chemotherapy (including hormonal and molecularly targeted therapy), radiation, surgery, and biologic therapy (immunotherapy and gene therapy).
• These treatments vary based on the location of the cancer, the size of the cancer and the overall health of the patient.
• Various interventions and nutrition therapy should be used in combination.
• Interventions may include: focus on nutritional concerns with surgery, during chemotherapy and radiation treatment, before/after surgery, for hematologic cell transplantation, focused monitoring and evaluation.

Nutrition Therapy

• Malnutrition is associated with cancer and cancer treatment, affecting 30-70% of patients and impacting mortality.
• Primary goals with nutrition therapy are to prevent malnutrition, establish individualized nutrition interventions, and improve nutritional recovery during and after treatment.
• Nutritional assessments (such as using the MUST, MST, or PG-SGA tools) and calculating individualized fluid and energy/protein requirements are important in managing cancer patients.
• Treatment goals should minimize negative impacts on health and maximizing the patient's overall nutritional parameters.
• Various specific nutrition interventions are present, from managing specific side effects (such as anorexia, nausea/vomiting, mucositis) to addressing cancer cachexia (and related treatment).