Understanding Cancer: Types, Causes, and Treatments
Cancer is the second leading cause of death globally, with one in four deaths attributed to it. This text explores the basic definitions of cancer, its classification by tissue origin, and the mutation process that leads to uncontrolled cell growth. It highlights common types of cancer, including breast and lung cancer, their risk factors, diagnostic methods, and treatment options. Emphasis is placed on the importance of screening and lifestyle factors that contribute to cancer incidence, offering a comprehensive overview for better awareness and prevention.
Understanding Cancer: Types, Causes, and Treatments
E N D
Presentation Transcript
Cancer • 2nd leading cause of death. What do you think is the 1st? • 1 out of 4 deaths is due to some form of cancer • 1/3 of the cancers are attributed or linked to conditions such as: • Obesity • Physical inactivity • Nutritional problems • Smoking • Other lifestyle factors
What is Cancer? • Classified by the tissues or blood cells from which it originates. • Most cancers are derived from epithelial tissues called carcinoma • Adenocarcinoma – glandular tissue • Sarcoma – connective, muscle, & bones • Gliomas – brain & spinal cord tissue • Melanoma – pigment cells • Myeloma – plasma cells • Lymphoma – lymph cells • Leukemia – leukocytes • Erythroleukemia - erythrocytes
What is Cancer? • First develops as a mutation in a single cell. • The mutated cell never matures into a mature normal cells • The cell reproduces at a fast rate (usually faster than normal cells) • Uncontrolled growing cells invades nearby tissue • If the growing cells invade other tissues in other locations, the term is metastasis
Causes of cancer • Malfunction of genes that controls cell growth • Carcinogenesis – cell’s transformation from normal to cancer • Virus factor – HPV, Herpes simplex, Hep B, Hep C, HIV, Epstein Barr • Overexposed cells – Skin cancer • Air – Tobacco – lung, bladder, throat, mouth, pancreatic • Asbestos – lung cancer • Immune factor - transplant patients develop Kaposi’s sarcoma or non-Hodgkin’s lymphoma • Genetics – 5-10% are hereditary • Food – colorectal cancer (high protein, high fat, nitrates) • Hormones – Estrogen linked to breast cancer
Screening • See Handout
Cancer metastasis • Cancer mets by 3 ways • Circulation through the blood & lymphatic system • Travel through the vein, commonly to liver & lungs • Accidental transplantation during surgery • Spreading to adjacent organs & tissues • Seeding – Cancer penetrate the wall of an organ, move into a body cavity, & spread throughout the area
Breast Cancer • Most common cancer affecting women • 1/7 women develop breast cancer by the age of 85 • No exact cause • 5% linked to genes BBCA 1 & BBCA 2 (inherited by mother or father); if you have the gene, you have a 80% chance of having breast cancer • Also linked to ovarian cancer (20 - 40% chance)
Classified into 2 common types • Ductal (most common) • Carcinoma in situ • Infiltrating (invasive) • Develops within the ducts • Lobular • Carcinoma in situ • Infiltrating (invasive) • Develops within the lobes • Invasive – 90% break through the duct walls & encroach on other breast tissues • Non-invasive – confined to duct in which they originate
Risk Factors • Family History • Radiation exposure • Premenopausal woman older than age 45 • Obesity • Age • Recent use of hormonal contraceptives • Early onset of menses or late menopause • Nulligravida • First pregnancy after age 30 • High fat diet • Colon, endometrial, or ovarian cancer • Postmenopausal hormone therapy (progestin & estrogen) • Alcohol use • Benign breast disease
Diagnosis • Self – breast exam • Mammography • Fine needle aspiration & excision biopsy • Hormone receptor assay • Ultrasonography • Bone scans, CAT scan for mets • Ductal lavage
Treatment • Lumpectomy in well – defined tumors • Radiation follows • Mastectomy • Partial – tumor & wedge of normal tissue • Total – removal all breast tissue • Modified Radical – entire breast, axillary nodes, & lining of chest wall • Chemotherapy • Common cyclophosphamide, methotrexate, doxurubicin, & fluorouracil • Hormone therapy
Lung Cancer • Largely preventable • Number 1 cancer killer of both men & women of the world • 2 major classes • Small Cell (20%) • Hormonal cells in the lung • Include oat cell, intermediate, combined • Very aggressive; usually already metastasized when diagnosed • Non-small cell most common • Adenocarcinoma – most common. In bronchial epithelium & mets early; appears as infiltrates; not usually associated with smoking • Squamous cell – squamous bronchial epithelium; central located. Found on chest xray. Mets late. Usually mets to bones • Large cell – highly anaplastic; aggressive; mets early • PROGNOSIS: ABOUT 13% SURVIVE 5 YEARS AFTER DX
Lung Cancer • Decreased occurrence since 1990 • 80-90% lung cancer is caused by smoking • # of cigarettes & length of smoking impact the occurrence of cancer • COPD increases risk for lung cancer
Patient presentation • Hemoptysis • Enlarged supraclavicular node (especially in smokers) • Pneumonia that does not clear up with antibiotics • May present with endocrine disorder such as Cushing’s
Diagnostic Testing • Chest x-ray • Cytological sputum • Bronchoscopy • Needle biopsy • CT scan • Bone scan
Treatment • Surgery • Radiation • Chemotherapy • Cyclophosphamide, doxorubicin, vincreitine • Patient usually have recurrence 7 – 14 months
Malignant Melanoma • 7th most common cancer in US but only 4% of all skin cancer • Slightly more common in women. WHY? • What age group do you think?? • What cells do you think this cancer occurs? • Melanocytes are located in: • Skin • Meninges • Alimentary canal • Respiratory canal • Lymph nodes
Common factors • Sun exposure • Fair traits • Nevi • Family history • Immunosuppresion
Metastasis • Spreads through the lymphatic & vascular system • Usually to regional lymph nodes, skin, liver, lungs, & CNS • COMMON SITES FOR TUMOR: Men – head & neck Women – legs
Diagnosis • Excisional biopsy • Punch biopsy • Chest x ray, CT, Bone scan, MRI for mets
Colorectal Cancer • 10-15% of all new cancer • Equal in both sexes & 3rd most cancer deaths • Usually progresses slowly • Most common people older than 50 (primary risk factor) • Colon Polyps • High fat, low fiber • Pre-existing conditions • Ulcerative colitis • Crohn’s disease • Hereditary nonpolyposis colorectal carcinoma • Pelvic cancers
Couch Potato Factor • Smoking • Alcohol consumption • Obesity • Physical inactivity • Aspirin and estrogen replacement may help prevent
Early stages • No real symptoms • Rectal bleeding in stool • Change in bowel habits • Cramping pain in lower abdomen
Diagnostic testing • Digital rectal examination • Fecal occult test • Proctoscopy • Colonoscopy • CT • Liver function test • Carcinoembryonic antigen
Treatment • Surgery • Chemotherapy • Oxaliplagin • Radiation
Hodgkin’s disease • Painless • Cause is unknown but may be linked to a virus • Enlargement of the lymph nodes, spleen, & other lymphatic tissue • May be linked to Epstein Barr virus; herbicide
Signs & symptoms • Painless swelling of lymph nodes, usually in neck then axilla • Night sweats • Cancerous mass in spleen, liver, & bones • Painless swelling of the face & neck • Anemia • Jaundice • Nerve pain • Increased susceptibility to infection • Intermittent fever
Testing • Lymph node biopsy for the presence of Reed-Sternberg cells, nodular fibrosis & necrosis • Bone marrow, liver, mediastinal & spleen biopsy • Chest x ray, CT • Hematologica l tests
Leukemia • ALL – Acute Lymphocytic Leukemia • 80% of childhood leukemia • 81% 5 yrsurvivial rate • AML – Acute Myeloid Leukemia • Most common in adults • Survivial is 1 year • CLL – Chronic Lymphocytic Leukemia • Most benign & slowest progression • Most common in elderly • CML – Chronic myeloid Leukemia • Most common in middle age • 20% of leukemia
Prostate Cancer • Most common cancer affecting men • 2nd cause of death • African American men are 2x more likely to die • Most common is Adenocarcinoma • Slow growing • Progression is usually Prostate to capsule along the ejaculatory ducts to the seminal vesicles
Risk Factors • Age (usually over 65 yo) • Diet high in saturated fats • Ethnicity
Survival • 70% at 5 years when it is localized in prostate • Metastasized: survival is 35% • Fatal when it has bone metastasis
Signs & Symptoms • Usually no symptoms at early stage • Advanced diseases: • Slow Urinary Stream • Hematuria • Urinary hesitancy • Incomplete bladder emptying • dysuria
Testing • DRE • Biopsy • Blood levels of prostate – specific antigen (PSA) • Transrectal prostatic ultrasonography • Bone scan • MRI
Staging • See packet