Overview
This lecture covers the fundamentals of cancer biology, risk factors, cancer classification, prevention, detection, and an introduction to cancer nursing care, focusing on patient comfort.
Anatomy & Physiology of Normal Cells
- Cells are the smallest structural and functional body units, with a plasma membrane, cytoplasm, and nucleus.
- The nucleus contains DNA; genes code for proteins needed for cellular functions.
- Protein synthesis involves transcription (copying DNA code) and translation (assembling proteins at ribosomes).
- DNA mutations can occur from ultraviolet rays or chemicals, leading to abnormal protein synthesis and possibly cancer.
- Mitosis is the process of cell division for growth and replacing injured cells; not all tissues have the same mitotic capability.
Cancer Concepts & Pathophysiology
- Oncology is the medical branch dealing with tumors and malignancies; oncology nurses aid from prevention to palliation.
- Cancer develops due to mutations, abnormal growth cycles, and loss of normal cell communication.
- Tumors are neoplasms: benign (localized, slow-growing) or malignant (invasive, fast-growing, can metastasize).
- Cancer cells lack division limits and do not respond to growth regulation signals.
Etiology & Risk Factors
- Cancer develops through initiation (mutation), promotion (mutated cell proliferation), and progression (further mutations, metastasis).
- Risk factors include viruses (e.g., HPV, EBV), radiation, chemicals, chronic irritation, genetics, diet, hormones, obesity, and immune suppression.
- Smoking and alcohol significantly increase cancer risk; occupational exposures (e.g., asbestos) are important.
Cancer Classification & Metastasis
- Cancers are classified by tissue origin: carcinoma (epithelial), sarcoma (connective), leukemia (blood), lymphoma (lymph), melanoma (skin).
- Metastasis is the spread of cancer to distant sites via blood or lymphatic systems; metastatic tumors retain primary site characteristics.
Cancer Incidence & Prevention
- Cancer is more common in older adults, with risk rising after age 50; skin cancer is most common and preventable.
- Common cancers by group: lung (highest mortality), prostate (men), breast (women), colon/rectal (both).
- Healthy lifestyle (diet, exercise, avoiding tobacco/alcohol) lowers risk; vaccinations (HPV, hepatitis B) prevent related cancers.
Early Detection & Screening
- Early detection is vital; nurses educate on risk factors and recommend screening.
- Regular screenings: mammography (breast), Pap/HPV tests (cervical), colorectal tests (colonoscopy, fecal tests), and PSA (prostate).
- New blood tests (e.g., CancerSEEK) and genetic testing help identify cancer risk.
Diagnosis of Cancer
- Diagnosis includes physical exam, medical and family history, and biopsy (tissue sample analysis).
- Radiological procedures (x-rays, mammography) are used to detect tumors.
- Biopsy is the definitive method for cancer diagnosis.
Key Terms & Definitions
- Oncology — the study and treatment of tumors.
- Neoplasm — any abnormal growth, benign or malignant.
- Carcinogen — substance or agent increasing cancer risk.
- Metastasis — the spread of cancer cells from the primary site to other body parts.
- Remission — disappearance of all signs and symptoms of cancer.
Action Items / Next Steps
- Review cancer risk factors and prevention strategies.
- Study nursing interventions for cancer detection and patient comfort.
- Complete assigned readings in Chapter 11, pages 142–151.
- Prepare for next lecture on diagnostic imaging and contrast media.