Cancer Chemotherapy & Prevention Quiz

Cancer Chemotherapy & Treatment

• Cancer (neoplasm, tumor, or malignancy) is a group of diseases characterized by uncontrolled cellular growth, tissue infiltration, and spread of abnormal cells. These cells cannot perform normal physiological functions.
• Cancer cells proliferate, unlike normal cells which eventually stop dividing.

Cancer Prevention

• Most cancers are not curable in advanced stages.
• Lifestyle modifications and chemoprevention agents can reduce the risk of developing cancer.
• FDA-approved vaccines can help prevent infection with certain viruses linked to specific cancers. Examples include HPV (cervical, vulva, vagina, anus cancers), and hepatitis B (liver cancer).
• Medications such as SERMs (tamoxifen, raloxifene) and aromatase inhibitors (exemestane) for breast cancer can reduce the risk in pre/postmenopausal women. Risks and benefits need careful consideration.

Smoking & Cancer Risk

• Smoking cessation reduces cancer risk (lung, pharynx/mouth, esophagus), but significant risk reduction takes more than 5 years.

Sun Protection & Skin Cancer

• Proper sun protection (SPF ≥ 15 sunscreen, protective clothing, sunglasses) reduces skin cancer risk.

Carcinogenesis

• Carcinogenesis is the process where normal cells transform into cancer cells.
• The exact cause of cancer remains unknown, and likely diverse. Abnormal mechanisms for growth and proliferation are altered.
• Cancer development stages: Initiation, Promotion, Transformation, Progression.

Cancer Genes

• Carcinogenesis involves oncogenes (genes that accelerate proliferation) and mutations in tumor suppressor genes (genes that inhibit inappropriate cellular growth/proliferation). Examples include p53.
• Protooncogens can become oncogenes by carcinogenic substances (e.g. smoking, radiation).

Carcinogenic Substances

• Chemicals like aniline and benzene are associated with bladder cancer and leukemia, respectively.
• Environmental factors like excessive sun exposure cause skin cancer; smoking is a known lung cancer cause.
• Viruses such as HPV, Epstein-Barr virus, and hepatitis B are linked to cancers.

Metastasis

• Metastasis is the growth of cancer cells at a distance from the primary tumor site.
• Often associated with a poorer prognosis; cancer is usually considered incurable after distant metastasis.
• Metastasis occurs through the bloodstream (hematogenous) or lymphatic systems.
• Common metastatic sites in solid tumors are the brain, bone, lungs, and liver.

Tumor Types

• Tumors are benign or malignant.
• Benign tumors are typically encapsulated, localized, and non-invasive. Recurrent after removal is rare.
• Malignant tumors are often invasive, spread widely, and can recur.
• Tumors arise from 4 tissue types: epithelial (carcinoma), connective (sarcoma), lymphoid, or nerve tissue. Examples include adenocarcinomas that arise from glandular tissue (e.g., lung, breast, colon).
• Malignancies of bone marrow or lymphoid tissue (like leukemia, lymphoma) are named separately.
• Precancerous cells show abnormal changes but are not yet malignant (hyperplastic or dysplastic).

Cancer Treatment

• Chemotherapy may be used to cure or control symptoms.
• Palliative care, using pharmacologic and nonpharmacologic treatments, improves quality of life.
• Main treatments: Surgery, Radiation, and Pharmacologic therapy.
• Surgery is useful for tissues and limited disease, but has limited role in widespread disease.

Chemotherapy

• Chemotherapeutic agents are narrow therapeutic index with doses given at regular intervals (cycles) to allow recovery.
• Adjuvant chemotherapy may eliminate microscopic malignant cells following surgery to prevent recurrence.
• Neoadjuvant chemotherapy may shrink tumor before surgery.
• Combination chemotherapy uses agents with different mechanisms of action to address potential toxicity and resistance. This may reduce development of resistance but can increase overall toxicity.
• Dose density of chemotherapy optimizes the time between cycles.
• Factors impacting chemotherapy selection and dosage include patient age, co-existing conditions, and performance status.