Ch13 cancer

Chapter 13 Cancer

What Is Cancer?

• Cancer is actually many diseases. • Cancer cells display abnormal:

– Growth – Division – Differentiation

• Cancer cells: – Metastasize – Form masses called malignant tumors – Do not stop growing and dividing at

appropriate times.

How Cancers Develop and Spread

• Cancer develops only in cells with damaged genes (mutations). – Mutations can be inherited or caused by

exposure to: –Low-dose radiation –Drugs –Toxic chemicals

– Infection with certain viruses can cause mutations.

– Lifestyle plays a major role in cancer prevention.


Genes and Cancer Development • Oncogenes – “on” switches that speed cell growth.

– Successive mutations to the hereditary material of particular body cells produce oncogenes.

• Tumor-suppressor genes – “off” switches that slow cell growth. – If tumor-suppressor genes mutate, they will no

longer restrict cell growth. • Benign tumors are surrounded by a fibrous

capsule, and they do not spread or invade surrounding tissues.


Metastasis – Cancer cells have the ability to spread, or

metastasize, from where they develop to other parts of the body.

– Cells that metastasize are called malignant – Cancer cells can enter the bloodstream or

lymphatic system and travel to other parts of the body and form new tumors.


Metastasis • Cancers are named according to the type of tissue

from which they develop. – Carcinomas arise from epithelial tissue.

• Tissues that line and cover internal and external body surfaces, such as skin.

– Sarcomas arise from connective or muscle tissue.

– Leukemias are cancers of the blood and related cells.

– Lymphomas are cancers of the lymphatic system.

– Cancers of the nervous system have various names.

Cancer Detection and Staging

• Cancer screening is an examination to detect cancer before a person has symptoms.

• American Cancer Society recommends screening for early detection, particularly for high-risk people or people with symptoms. – Visual examination – Self-examination – Clinical (physician) examination – Laboratory testing – Scans (MRI, CAT)

Cancer Detection and Staging• Cancer staging describes the extent of growth

and metastasis of cancer. • It is useful in determining appropriate therapy. • It also helps provide prognosis. • TNM system of staging:

– T describes the original tumor – N describes if cancer has reached lymph

nodes – M describes if cancer has metastasized

• The overall stages are I, II, III, and IV.

Cancer Treatment• Principal forms of treatment are surgery, radiation,

and chemotherapy. Surgery removes localized cancers.

– Most cancer cures are accomplished by surgery.

Radiation kills localized cancers: used alone or with surgery.

Chemotherapy inhibits cancer cell reproduction or destroys metastasized cancer cells. – Used most often when cancer has spread

• Radiation and chemotherapy also kill or damage healthy cells and may cause serious side effects (i.e., nausea, hair loss).

Cancer Treatment

Laser and Photodynamic Therapy – Lasers are high intensity lights that can be

focused with great precision – Remove superficial cancers as well as those in

interior body locations. – Chemical called photosensitizer reacts with

special light, killing tumor cells – Tumor cells become targets for treatment

because they absorb photosensitzer better than healthy cells

Cancer TreatmentTargeted Therapies

– Drugs or other substances that block the growth and spread of cancer by interfering with specific molecules involved in tumor growth and progression.

– Small-molecule Drugs • Do a specific job, such as blocking certain

enzymes and growth factor receptors, modifying the function of proteins that regulate cancer cell functions, and stopping cancerous tumors from developing new blood vessels.

Cancer Treatment

Targeted Therapies – Immunotherapy

• Biomodulation (biological response modification) is the manipulation of the immune system to rid the body of its cancer.

• Key to the working of the immune system is its ability to recognize an intruder as foreign.

Cancer TreatmentBone Marrow and Peripheral Blood Stem Cell

Transplants – Patients receive stem cell transplants in a

process that’s like receiving a blood donation. – Used in two ways:

• To resupply the bone marrow when it has been destroyed by chemotherapy or radiation.

• To supply healthy stem cells to a person who has cancer of the blood-forming tissue, such as leukemia.

Prevalent Cancers in the United States

– Heredity is a risk factor. However, behavioral factors such as cigarette smoking, dietary patterns, physical activity, and weight control substantially affect the risk of cancer.

– Advanced age is a significant risk factor for most cancers except certain childhood cancers, cervical and testicular cancers, and to some extent, breast cancer.

Prevalent Cancers in the United StatesCancers Caused By or Related to Tobacco Use • Lung Cancer

– Lung cancer is the leading cause of cancer deaths

– Signs and Symptoms • Chronic cough, excess sputum, wheezing,

chest pain, and lung infection. • Chest X-rays, MRI and CT scans; analyses

of the types of cells in the sputum; and fiber optic examination of the bronchial passageways assist in diagnoses.


Cancers Caused By or Related to Tobacco Use • Lung Cancer

– Risk factors and prevention • The number of cigarettes smoked/day • The number of years a person smokes • How deeply he or she inhales • Smoking high-tar or unfiltered cigarettes • Quitting smoking reduces the risk of

developing lung cancer, after 10 years it will be about half that of a person who continued to smoke.



– Risk factors and prevention (cont.) • High consumption of alcoholic beverages

and obesity • Passive smoking is associated with a 20% to

30% increase in lung cancer risk. • Asbestos particle inhalation • Radon Gas exposure appears to multiply the

carcinogenic effects of tobacco smoke.



– Treatment • Physicians treat lung cancer with surgery,

radiation, and chemotherapy.

Prevalent Cancers in the United StatesCancers Caused By or Related to Tobacco Use • Cancers of the Larynx, Oral Cavity, and

Esophagus – Caused by tobacco & alcohol use as well as

HPV – Hoarse voice, difficulty swallowing, and a sore

throat may indicate larynx cancer. – Recurrent heartburn may indicate esophageal

cancer. – Oral cancer tumors are easy to detect because

they are visible but they metastasize quickly.


Cancers Caused By or Related to Tobacco Use • Cancers of the Kidney and Bladder

– Come in contact with inhaled carcinogens after the substances enter the bloodstream.

– Blood in the urine is a sign of kidney or bladder cancer. Frequent, urgent, or difficult urination are also signs of bladder cancer.

– Men who are over 50 years old and are heavy smokers have a high risk of these cancers.


Cancers Caused By or Related to Tobacco Use • Cancers of the Pancreas

– “silent” cancer because its early symptoms (nausea, vomiting, weakness and discomfort in the abdomen) are vague and, therefore, the disease often is undetected as it progresses.

– Obesity, a high-fat diet, physical inactivity, and diabetes are other risk factors for the disease.

– Only 6% of people who have pancreatic cancer survive beyond 5 years.


Cancers Caused By or Related to Tobacco Use • Acute Myeloid Leukemia

– This form of cancer affects blood-producing cells in bone marrow.

– As a result of this disease, fewer white blood cells are produced, particularly the ones that combat bacterial infections.

– Exposure to benzene and ionizing radiation increases the risk of AML.

– Benzene and substances that emit ionizing radiation are in cigarette smoke.


Cancers Related to Diet • Each year, poor diet

and lack of physical activity (including obesity) account for about one-third of cancer deaths in the United States.

Prevalent Cancers in the United StatesCancers Related to Diet • Cancer of the Stomach

– incidence of and death rate from stomach cancer has declined dramatically over the past 60 to 70 years in the United States.

– “silent” in its early stages. Symptoms may be attributed to minor intestinal upsets.

– Risk increases with age – Diets high in salt-cured, nitrate-cured, or

smoked foods consuming alcohol and cigarette smoking also are risk factors


Cancers Related to Diet • Cancer of the Colon and Rectum

– Colorectal cancer is the third most deadly cancer in the United States.

– Signs and symptoms depend on location of the tumor.

– Abdominal pain, change in bowel habits, and blood in the stools are important signs.



– Risk factors include: advanced age; heredity; personal or family history of colorectal polyps or inflammatory bowel disease; physical inactivity; obesity; diets high in fat and/or red meat; inadequate intake of fruits and vegetables; smoking cigarettes; and having more than one alcoholic drink/day.



– Low-dose aspirin, exercising moderately and consistently, consuming a diet that contains adequate amounts of fruits, vegetables, and whole grains; replaces red and processed meats with chicken and fish; and replacing most saturated fats with unsaturated fats can reduce the risk of colorectal cancer.


Cancers Related to Hormone Function • Breast Cancer

– Breast cancer is the second leading cancer killer of women in the United States

– Signs and Symptoms • Changes in the breast tissue, including

lumps in the breast; dimpling, thickening, discoloration, irritation, or scaling of the breast skin; tenderness of the nipple or nipple discharge; and swelling or distortion of the breast.



– Risk factors • Family history – first –degree relative • Age (20-70)



– Risk factors • High cumulative exposure to ovarian

hormones, particularly estrogen –Early menarche (younger than age 12) –Late menopause (older than age 55) –Not bearing children –Currently taking oral contraceptives –High-fat diet and obesity may contribute to

estrogen levels



– Early Detection • Breast self-examinations are now considered

optional by the American Cancer Society. • Clinical breast exams • Mammography

– Treatment : • Lumpectomy • Radiation • Total mastectomy • Chemotherapy • Radical mastectomy • Hormonal • Modified radical mastectomy


Cancers Related to Hormone Function • Endometrial Cancer

– The endometrium is the lining of the uterus. – Endometrial cancer is most common in

postmenopausal women. – Primary symptom is abnormal uterine bleeding. – Pap tests for cervical cancer do not reveal

endometrial cancer. • Endometrial biopsy is needed.


Cancers Related to Hormone Function • Endometrial Cancer

– Primary risk factor is high cumulative exposure to estrogen. • Hormone replacement therapy involving

estrogen without progesterone is a risk factor as well.

– Using combination oral contraceptives reduces risk.

– Treatments include total hysterectomy, radiation, hormones and/or chemotherapy.


Cancers Related to Viral Infection • Cervical Cancer • The incidence has declined dramatically since

1960 due to Pap test screening. • Most women have no signs or symptoms when

diagnosed with the disease. • Most often develops in women 20 to 40 years

of age. • Treatments include surgery, radiation, laser

treatment, and cryotherapy.


Cancers Related to Viral Infection • Cervical Cancer

– A causal association exists between infection with human papillomavirus (HPV) and cervical cancer. • Causes genital warts • Is sexually transmitted • Risk of infection increases with an increased

number of sexual partners and/or non-monogamous partners

• Women who became sexually active before age 17 have higher risk



– Long-term use of oral contraceptives is associated with an increased risk of cervical cancer.

– The vaccine, Gardasil, prevents infection with four types of HPV.

– The American Cancer Society (ACS) recommends that all women should have annual Pap tests three years after their first vaginal intercourse but not later than age 21.



– Treatment • Surgery • Electrocoagulation • Cryotherapy • Carbon dioxide laser surgery


Cancers Related to Ultraviolet Radiation • Related to exposure to ultraviolet (UV) radiation

from the sun as well as tanning beds. • Three types of UV radiation: UVA, UVB, and

UVC. • All types are harmful and have potential to cause

skin cancer. • UVA is associated with sunburn, skin cancer

formation, and premature aging effects. • Artificial UV sources may also generate UVC

rays • UVC is potent cancer-causing radiation


Cancers Related to Ultraviolet Radiation Basal cell carcinoma

– May look like moles, or pimples with pearl-like borders

– May crust, scale, and bleed – Treatment

• Removed by surgery and cryotherapy • Cure rate is high


Cancers Related to Ultraviolet Radiation Squamous Cell Carcinoma

– Flat, red, scaling lesions – May be slightly elevated – Also develops in dark-skinned populations from

chemical exposure, X-rays, burns, and chronic skin ulcers

– Treatment • Removed by surgery and cryotherapy


Cancers Related to Ultraviolet Radiation Malignant Melanoma

– Deadly skin cancer – Most frequent cancer in women aged 25 to 29

and second most frequent cancer in women aged 30 to 34

– Fair-skinned people have higher risk than dark-skinned people • Highest risk: people with light blue eyes, very

light hair, and skin that burns easily and freckles rather than tans


Cancers Related to Ultraviolet Radiation Malignant Melanoma

– Check skin regularly for skin legions that: • Are asymmetrical • Have irregular borders • Have multiple colors • Have a diameter greater than pencil eraser

– Prevention • Limit sun exposure • Use sunscreens • Where protective clothing when exposed to

sunlight • Avoid artificial sources of UV light (i.e., tanning

beds)


Cancers Related to Ultraviolet Radiation Prostate Cancer • The most prevalent cancer in men • Signs and symptoms that may be nonspecific:

– Uneven flow of urine – Incomplete emptying of bladder – Reduced urine flow – Urinating more frequently at night

• Signs and symptoms likely to be related to prostate cancer: – Pain in the pelvis – Sudden development of impotence – Blood in the urine


Cancers Related to Ultraviolet Radiation Prostate Cancer

– Risk factors • Location: men living in North America and

northwestern Europe • Race: African Americans and Jamaicans of

African descent have the highest prostate incidence rate

• Advanced age • Heredity • Obesity and high-fat diet


Cancers Related to Ultraviolet Radiation Prostate Cancer

– An annual digital rectal exam and PSA blood test is recommended for men older than 50.

– Prostate cancer is often slow growing, and most patients die of other causes.

– “Watchful waiting” is often treatment of choice, although recent research challenges this view.


Cancers Related to Ultraviolet Radiation Testicular Cancer

– Testicular cancer is rare and highly curable – Signs and symptoms

• Painless, swollen testis • Sensation of heaviness or aching in the

testis • Small lump in one testis


Cancers Related to Ultraviolet Radiation Testicular Cancer

– Risk factors • Age: strikes primarily teenagers and men

between the ages of 15 and 35 • Failure for testis to descend into scrotal sac

by age 6 – Detection

• Conduct testicular self-exam each month after a warm bath or shower


Cancers Related to Ultraviolet Radiation Ovarian Cancer

– No signs and symptoms in early stage. – As disease progresses:

• Frequent urination or bloating • Pressure in the abdomen • Vaginal bleeding in postmenopausal women • Irregular or heavy menses in

premenopausal women – Occurs most often after menopause.



– Risk factors • Advanced age (85% to 90% develop in

postmenopausal women) • Early menarche • Late menopause • Not bearing children • Living in a Western country • Obesity • Use of oral contraceptives reduces risk



– Detection • No accurate routine screening test for

women at average risk is available. • Pelvic examination, transvaginal ultrasound,

and blood tests can detect abnormalities. – Treatment

• Surgery • Chemotherapy • Radiation

Reducing Your Risk for Cancer

• Eat a diet low in fat and red meats, especially high-fat and processed meats.

• Eat a variety of fruits and vegetables daily. • Follow ACS’s recommendations for cancer

screening tests. • Men should conduct monthly testicular self-

examinations. • Know warning signs of cancer and see your

health care provider immediately if you detect any.


• Sexually active people should use condoms to avoid contacting HPV.

• Maintain a healthy weight. • Women should consult with their health care

providers about risks of using oral contraceptives or hormone replacement therapy.

• Exercise most days of the week. • When in the sun, takes steps to limit UV radiation

exposure.


• Don’t smoke or chew tobacco. • Avoid secondhand smoke. • Don’t drink excessive amounts of alcohol. • Avoid unnecessary exposure to ionizing radiation,

such as x-rays and UV light. • Don’t lie in the sun or tanning beds. • Avoid direct sun exposure between 10 a.m. and 4

p.m. • Avoid exposure to toxic chemicals and fumes. • Avoid asbestos dust and radon gas. • Avoid eating cured or smoked meats.

Ch13 cancer

Education

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