Biology Quiz: Cancer Cells and Stages

Biological Characteristics of Cancer Cells

• Cancer cells have unlimited reproduction capabilities.
• They secrete toxic and proteolytic enzymes.
• They can perform phagocytosis.
• They have motility, which enables them to metastasize.
• They lack cohesion, allowing them to pass into the lymph stream.
• They are immortal.

Stages of Cancer

• Stage 1: Precancerous cells
• Stage 2: Cancer cells
• Stage 3: Proliferation of cancer cells, resulting in metastasis

Risk Factors for Cancer

• Infections
• Radiation
• Immunosuppressive drugs
• Diet and nutrition
• Alcohol
• Cigarette smoking

Carcinogenesis and Nutrition

• Dietary fat can increase the risk of cancer
• Processes applied to fat, such as acrolein and malonaldehyde, can increase the risk of cancer
• Oxidation products can cause DNA damage and increase the risk of cancer

Metabolic Changes in Cancer

• Lipid metabolism: lipolysis increases, lipogenesis is reduced, and lipoprotein lipase activity is reduced
• Lipid metabolism: triglycerides increase, high-density lipoprotein (HDL) decreases, and venous glycerol increases
• Protein metabolism: whole body protein turnover increases, muscle protein synthesis is reduced, and tumor protein synthesis increases
• Glucose metabolism: glucose synthesis increases, and glucose tolerance and turnover are reduced

The Effect of Cancer on an Individual's Nutritional Status

• Anorexia: caused by peptides, oligonucleotides, and other metabolites produced by the tumor
• Negative nitrogen balance: nitrogen is retained by the tumor

Cachexia

• A metabolic state resulting from multiple metabolic disorders
• Characterized by weight loss, muscle breakdown, anorexia, asthenia, depression, and chronic nausea
• It is seen in 2/3 of malignant patients and is inversely correlated with survival and indicates poor prognosis