Cancer Risk Factors and Diagnosis

Environmental and Lifestyle Factors in Cancer Development

• Exposure to carcinogens, such as tobacco smoke, radiation, and certain chemicals, can increase cancer risk
• Prolonged exposure to UV radiation from the sun or tanning beds increases risk of skin cancer
• Infection with certain viruses, bacteria, and parasites can increase cancer risk, e.g. HPV and cervical cancer, H. pylori and stomach cancer
• Diet high in processed and red meat, low in fruits and vegetables, may increase cancer risk
• Sedentary lifestyle and obesity linked to increased risk of certain cancers, such as colon and breast cancer
• Family history and inherited genetic mutations can increase cancer risk

Clinical Manifestations of Cancer

• Unexplained weight loss, fever, or fatigue
• Pain, such as bone pain, headaches, or abdominal pain
• Skin changes, including skin lesions, ulcers, or changes in mole appearance
• Changes in bladder or bowel habits, such as blood in urine or stool
• Coughing or difficulty breathing
• Lumps or thickening in breast, testicles, or elsewhere
• Abnormal bleeding, such as vaginal bleeding or blood in stool

Diagnostic Techniques

• Imaging tests, such as X-ray, CT, MRI, and PET scans, to visualize tumors and metastases
• Biopsy, where a sample of tissue is removed for microscopic examination
• Endoscopy, where a flexible tube with a camera is used to visualize internal organs
• Laboratory tests, such as blood tests, to detect tumor markers and genetic changes
• Genetic testing, such as BRCA1 and BRCA2, to identify inherited mutations

Grading and Staging Protocols

• Grading: classification of cancer cells based on how abnormal they appear under a microscope, with higher grades indicating more aggressive tumors
• Staging: classification of cancer based on its extent and spread, with stages ranging from I (localized) to IV (metastatic)
• TNM system: classification of cancer based on tumor size (T), lymph node involvement (N), and metastasis (M)