BBH Chapter 11 Cancer

Cancer

- a group of more than 100 diseases that share common characteristics. -involve uncontrolled cell proliferation that leads to the formation of a tumor, and the capability of those cancerous tumor cells of spreading to other sites in the body.

Race

-Black populations specifically have higher rates of cancer and cancer mortality than white populations. -reasons for these disparities may be complex and multifactorial, involving variables ranging from genetics to socioeconomic status to cultural influences on risky behaviors or behaviors that might help to identify cancer early (e.g. screening).

Stage 2 & 3

-Designation of stages II and III depend on the type of cancer involved. -Both stages involve growth in the primary site where the cancer formed, with stage III indicating more advanced growth. -In both stages, cancer may have invaded nearby lymph nodes.

Early life environment

-For example, if a child grows up in an environment where there is frequent smoking, poor dietary practices, or exposure to some other cancer-causing agents, this may increase her risk of developing cancer even if she does not have any other risk factors.

chemotherapy

-For tumors that have advanced further and are not likely to be able to be addressed with surgery, another approach is the use of medicine to treat -different medicines used in chemotherapy -most common approach involves anticancer medications that are designed to kill rapidly-dividing cells. -are non-selective, however, meaning they travel throughout the entire body and target any rapidly-dividing cells (not just cancer cells)

Sex

-On average, men are at a greater risk of developing cancer than women. -the reasons for this disparity are not completely clear, there may be a variety of factors involved. -Some of the difference may be due to biological differences like disparities in hormone levels. -drinking alcohol and smoking are behaviors more frequently seen in men than women. -Men are also more likely to have a number of other behavioral risk factors like poor diets, lack of exercise, etc. Regardless, these factors do not fully explain the disparity between men and women when it comes to cancer; there are likely other variables involved.

Age

-One of the greatest risk factors for cancer in general is increasing age. -About 50% of cancer cases occur in patients who are over the age of 70. -The contribution of age to cancer risk, however, is very much dependent on the type of cancer in question. Some types of cancer, like retinoblastoma for example, occur more commonly in younger age groups.

carcinoma

-These are by far the most common type of cancer. -cancers that form from the cells that line the inner and outer surfaces of the body, including the internal organs. -includes relatively common cancers like prostate, breast, lung, colon, and skin cancer. -account for about 85% of all cancers.

Stage 0

-a tumor has formed but it has not spread from its site of origin. -actually some debate as to whether or not tumors at this stage should be classified as cancerous. -Cells at this stage may display characteristics of cancer cells, but they don't yet have the potential for metastasis. -some physicians refer to this stage as pre-cancer.

Carcinogens

-agents that are known to cause cancer. -These can be natural and artificial substances, and exposure to carcinogens may be increased due to factors like behaviors, environments, etc. -exposure to carcinogens is in theory modifiable -Well-known carcinogens that are introduced as a result of behavior are alcohol and the substances found in tobacco products like cigarettes. -Radiation is a common environmental carcinogen, with ultraviolet radiation from the sun being the carcinogen all of us are forced to have some exposure to. -Carcinogens can lead to cancer via a number of different mechanisms, such as by causing damage to DNA or promoting the growth of tumors.

Diet

-can have direct and indirect effects on cancer risk. -Overconsumption of food can increase one's likelihood of becoming overweight or obese, which indirectly increases the risk of cancer. -are some foods that may act as carcinogens, causing diet to have a potential means of directly affecting risk. Red and processed meat, for example, have been identified by the International Agency for Research on Cancer (IARC) as potentially carcinogenic. -The specific reasons why these foods may increase cancer risk is not known

Overweight and obesity

-generally leads to poorer health, and thus may contribute to cancer risk indirectly. -thought to be ways in which being overweight can directly increase cancer risk. -Fat tissue, for example, might produce higher levels of hormones like estrogen that can increase the risk of cancer. -levels of physical activity are often associated with being overweight or obese, and physical activity itself is a modifiable risk factor for cancer

Radiation therapy

-involves the use of high doses of ionizing radiation, which is targeted at tumors. -high doses of radiation will kill cancerous cells. -will also kill healthy cells. -can lead to a variety of side effects including hair loss, fatigue, loss of appetite, and the death of immune system cells to cause disruptions in immune system functioning.

cancer is the second leading cause of death...

-it has held that position in the leading causes of death since 1938. -since cancer is something that all of us tend to fear to some extent, the statistics regarding cancer prevalence are somewhat disturbing. -Men have over a 40% of developing cancer at some point in their lifetime and women have close to a 40% chance (37.58% chance to be exact). And over 22% of men and 19% of women will die from cancer.

Biopsy

A biopsy is a test for cancer in which a small sample of the abnormal growth is removed and studied

Oncogene

A mutated gene that encourages the uncontrolled cell division that results in cancer.

Symptoms of Cancer are Broad and Hard to Define...

A thickening or lump in the breast or any other part of the body • A new mole or a change in an existing mole • A sore that does not heal • Hoarseness or a cough that does not go away • Changes in bowel or bladder habits ▪Discomfort after eating ▪Difficulty swallowing ▪Weight gain or loss with no known reason ▪Unusual bleeding or discharge ▪Feeling weak or very tired

Malignant melanoma

An especially aggressive form of skin cancer

In some cases, genes have been identified that, if mutated, may increase one's risk of developing cancer—but the likelihood they develop it still depends on the influence of other risk factors like behavior...

For example, there are known variations in two genes, called BRCA1 and BRCA2 (which stands for Breast Cancer genes 1 and 2) that can increase the likelihood a woman will develop breast cancer. -These genes encode for proteins that are involved in repairing damaged DNA, and the mutations thus disrupt DNA repair. -However, a mutation in one of these genes (or both) does not determine whether a woman will develop cancer; it just increases her risk. Around 45-65% of women with a mutation in one of these two genes will actually develop breast cancer.

Sarcomas

Sarcomas form from cells that make up muscles, bone, and connective tissue. These are much less common than carcinomas and include cancers like osteosarcoma (bone cancer).

True or false: 5-year survival rates vary significantly among different types of cancer; they also are very dependent on the stage the cancer was diagnosed at.

True

True or false More people are surviving cancer now than ever before, but disparities exist in cancer rates

Trye

Non-modifiable risk factors for cancer include

age, sex, race, and family history

5-year survival rates are

statistics used by physicians and patients to get an idea of the likelihood of survival after a cancer diagnosis. -refer to the proportion of patients who are typically alive 5 years after diagnosis with a particular form of cancer at a particular degree of advancement. -only indicate the percentage who are living---those living patients may still have cancer, they may be in the midst of intense treatment, or they may even be near the end of their lives. -ONLY indicates survival and is not otherwise indicative of the health of the patient.

Side effects of chemo

they also paffect hair follicles, immune system cells, cells in the digestive tract, cells in the reproductive system, etc. This can lead to a variety of serious side effects ranging from hair loss to disorders of the immune system.

Fun facts

• More than 1 million people develop skin cancer every year. • Out of 100 students, 26% (or 26 of you) will die of skin cancer • Behaviors can either increase, or decrease your risks.

Family History

-significant risk factor for cancer, and includes both genetic and environmental factors. -Genetics is often a risk factor for cancer, although it is rare for cancer genetics to be clear-cut. -cancer is not generally caused by a mutation in one gene. -Instead, there are networks of genes involved in cancer risk, and in many cases the genetic contribution to cancer is not fully understood.

Cancerous tumors are classified as malignant, and their defining feature is

-that their cells have the capability to break off from the primary tumor and travel via the bloodstream or lymphatic system to another location in the body, where they can form another tumor. -This process is known as metastasis.

Treatment for cancer is highly dependent on the

-the location and stage of the cancer.

Myeloma

Cancer of the bone marrow

Modifiable Risk Factors for Cancer

Carcinogens, overweight and obesity, diet

Scans

Imaging technologies can be used to detect cancers. • Ultrasound • Magnetic Resonance Imaging (MRI) • Computed Tomography (CT) • Positron Emission Tomography (PET)

Stage 1

In stage I, a tumor has displayed evident growth but remains in the tissue where it formed. At this stage, the tumor often is amenable to removal.

Stage 4

Stage IV is characterized by metastasis. This means that the cancer has spread to another part of the body and potentially started a secondary tumor.

Cancers that have not metastasized and have not advanced too extensively throughout a sensitive tissue may

be amenable to surgical removal. Removal of a tumor does not guarantee a tumor cannot grow back, but it is a preferred method of treatment if the tumor is amenable to it.

Leukemias

cancers primarily affect the bone marrow, where blood cells are produced. They lead to abnormalities in levels of white blood cells and impairments of immune system function.

Lymphomas

cancers that develop from cells in the lymphatic system. -Two well-known categories of lymphomas are Hodgkin and non-Hodgkin lymphoma.

4 Types of cancer

carcinomas, sarcomas, lymphomas, leukemias

Screening tests such as a mammogram and a colonoscopy can

detect cancers at specific sites.