Visualizing Human Bio Ch 12

What is cancer?

Cancer is defined as uncontrolled cell replication that occurs due to a breakdown in the normal mechanisms of cell regulation.

How many specific diseases are classified as cancer?

More than 100 specific diseases are classified under the term cancer.

What is the role of the immune system in relation to cancer?

The immune system destroys most potentially cancerous cells by recognizing them as 'non-self' and reacting to them.

What happens to cancer cells in terms of replication?

Cancer cells have unlimited potential to replicate and can avoid programmed cell death (apoptosis).

What are proto-oncogenes and tumor-suppressor genes?

Proto-oncogenes are growth promoters, while tumor-suppressor genes are growth-stoppers; mutations in these can lead to cancer.

What is the significance of telomeres in cancer cells?

Telomeres protect chromosome ends; if maintained by telomerase, cancer cells can replicate indefinitely.

What is angiogenesis?

Angiogenesis is the process by which new blood vessels are formed, allowing tumors to grow and become immortal.

What is metastasis?

Metastasis is the process by which cancer cells spread from the original tumor to secondary sites in the body.

What factors contribute to cancer development?

Cancer can be initiated and promoted by heredity, environment, viruses, and diet.

What are BRCA1 and BRCA2?

BRCA1 and BRCA2 are tumor-suppressor genes; mutations in these genes increase the risk of breast and ovarian cancer.

What are common environmental carcinogens?

Common environmental carcinogens include chemicals (like those in tobacco smoke) and radiation (like UV rays).

What is the five-year follow-up figure in cancer diagnosis?

It refers to the percentage of people diagnosed with cancer who are alive five years after their diagnosis.

What is a carcinoma in situ?

A carcinoma in situ is a localized cancerous growth that has not yet invaded surrounding tissues.

How does the immune system's weakness affect cancer progression?

A weakened immune system gives cancerous cells an advantage, allowing them to grow and multiply unchecked.

What happens when tumor-suppressor genes mutate?

Mutated tumor-suppressor genes fail to regulate the cell cycle and promote apoptosis, leading to cancer.

What is the typical number of times a cell can replicate before telomeres are completely worn out?

A typical cell can replicate 50-60 times before the telomeres are completely worn out.

What role do antigens play in cancer cells?

Many cancer cells have unique antigens on their surfaces that can be recognized and targeted by T cells.

What is the impact of industrial pollution on cancer risk?

Pregnant women and their fetuses are especially susceptible to industrial pollution, which can increase cancer risk.

What is the relationship between sunlight and skin cancer?

Over 80% of skin cancers are caused by exposure to higher-frequency ultraviolet B (UVB) rays from sunlight.

How do cancer cells exploit their advantages once they overcome the immune system?

Cancer cells can outcompete normal cells for space and nutrients, leading to unchecked growth.

What is the significance of mutations in control genes?

Mutations in control genes can initiate a cascade of mutations that lead to cancer development.

What is the role of angiogenic compounds in tumors?

Angiogenic compounds produced by tumors lure blood vessels into the tumor, facilitating its growth.

What is the percentage of cancer deaths linked to cigarette smoke?

Estimates suggest that 30-80% of cancer deaths are linked to cigarette smoke.

What type of radiation is linked to lung cancer and is released by natural sources?

Radon, a colorless, odorless gas released by water, soil, and rocks.

What is the second leading cause of lung cancer?

Radon exposure.

Which virus is most commonly associated with cervical cancer?

Human papilloma virus (HPV).

What cancers are linked to Epstein-Barr virus (EBV)?

Hodgkin's lymphoma and non-Hodgkin's lymphoma.

Which viruses are associated with liver cancer?

Hepatitis B and C viruses.

What is the relationship between HIV/AIDS and cancer?

HIV/AIDS is linked to non-Hodgkin's lymphoma and Kaposi's sarcoma.

Which virus is associated with T-cell non-Hodgkin's lymphoma?

Human T-cell leukemia/lymphoma virus.

How does obesity affect cancer risk?

Obesity is linked to a 50% or more increase in the incidence of colon cancer and breast and uterine cancer among women.

What types of diets are associated with an increased risk of colon cancer?

Diets high in animal fat from beef, pork, and dairy.

What chemicals in processed meats can increase cancer risk?

Nitrites, which convert into nitrosamines during digestion.

How can fish and shellfish contribute to cancer risk?

They may store carcinogenic substances from contaminated waters.

What is the link between alcohol consumption and cancer?

Excessive alcohol consumption is linked to cancers of the mouth, throat, esophagus, breast, and liver.

How do antioxidant vitamins affect cancer risk?

They may have a protective effect against cancer by counteracting free radicals.

What are the three most common and deadliest cancers?

Lung, colorectal, and breast cancer.

What is the leading risk factor for lung cancer?

Cigarette smoking.

What are common symptoms of lung cancer?

Persistent cough, frequent pneumonia or bronchitis, and changes in voice.

What initiates most colorectal cancers?

Most start as benign polyps.

What lifestyle factors increase the risk of colon cancer?

A high-fat, low-fiber diet and a sedentary lifestyle.

What is the screening test for colorectal cancer?

Colonoscopy.

What are the primary risk factors for breast cancer?

Being female, age, early menarche, late menopause, obesity, and hormonal contraceptive use.

How is breast cancer typically diagnosed?

Through a mammogram, an X-ray of breast tissue.

What are the three types of skin cancer?

Basal cell carcinoma, squamous cell carcinoma, and melanoma.

What are common symptoms of prostate cancer?

Difficulty urinating, blood in urine, or pelvic pain.

What is leukemia?

Cancer of the white blood cells.

What are common symptoms of leukemia?

Fatigue, weight loss, and frequent infections.

What is lymphoma?

A cancer that attacks the lymph nodes, with two main types: Hodgkin's disease and non-Hodgkin's lymphoma.

What are common symptoms of lymphoma?

Intermittent fever, weight loss, night sweats, and enlarged lymph nodes.

What is the typical treatment for leukemia?

Chemotherapy, often followed by a bone marrow transplant.

How can brain cancer typically arise?

It usually indicates metastatic disease from cancers of the breast, colon, or lung.

What are the four ways to definitively diagnose cancer?

Screening tests, imaging, tumor enzyme tests, and genetic tests.

What are the standard treatments for cancer?

Surgery, radiation therapy, and chemotherapy.

What does chemotherapy do?

Disrupts cell growth and targets fast-growing cells, but also affects healthy cells.

What are common side effects of cancer drugs?

Nausea, fatigue, hair loss, dry mouth, anemia, and reduced immune function.

What is the purpose of radiation therapy?

To interrupt cell growth in targeted areas, affecting both cancerous and healthy cells.

What are some experimental cancer treatments?

Genetic therapy, magnetism, and phototherapy.