Chapter 12 Flashcards
Is cancer a single disease? If no, what term does it refer to? Are the underlying processes of different forms of cancer the same?
> Cancer is not a single disease, but rather a term to refer to a group of more than 100 illnesses
> the basic process underlying dif-ferent types of cancer, however, is the same
What are the underlying processes of cancer?
> Cell proliferation normally is stringently regulated so that new cells are created to replace damaged or dying cells.
> Mechanisms are in place during cell division to repair damaged deoxyribonucleic acid or to activate programmed cell death if the DNA damage is too extensive to repair.
> DNA damage can occur due to genetic processes or damage from carcinogens or viruses.
What is cancer a result of?
> Importantly, cancer is typically a result of multiple gene mutations, and these mutations are usually acquired during the lifespan.
> When genes that regulate cell division have mutations the result is a breakdown in the regulation of cell division, leading to uncon-trolled cell proliferation
> The new tissue that develops from unregulated cell growth is called a tumour or neoplasm.
What kind of tumors are harmful? What do they do and what systems do they go through to achieve this?
> Malignant tumours are cancerous.
> Cells in malignant tumours can invade surrounding tissue and spread to a distant site in the body through the blood or lymph systems in a process called metastasis.
What kind of tumors are not harmful? Can they be removed? What do they not do?
> Benign tumours are not cancerous and typically are not life-threatening.
> Often, they can be removed and do not invade nearby tissue or metastasize
The main categories of cancer are broadly classified according to what?
> according to the tissue in which the cancer originates.
What is Carcinoma? Are most cancer carcinomas?
> Carcinoma: Malignant neoplasms (i.e., new, abnormal tissue growth) that develop in the cells of the skin or tis-sues that line or cover organs (e.g., res-piratory tract, reproductive tract). Most human cancers are carcinomas.
What is Sarcoma?
> Malignant neoplasms that develop in connective tissue, muscle, or bone.
What is Leukemia? (where does it form)?
> Cancer that develops in blood-forming tissue (e.g., bone marrow), causing a rapid proliferation of white blood cells.
What is Lymphoma?
Cancer of what system?
> Cancers of the lymphatic system.
Central nervous system cancer is cancer that develops in what two areas?
> Cancers that develop in brain tissue or the spinal cord.
Cancer type is typically named after what?
> the organ or type of cell in which the cancer initially develops (e.g., breast cancer for cancer that begins in breast tissue)
Cancer is a leading cause of death worldwide-
1. How many deaths are there?
2. What percentage of all deaths are cancer related?
> approximately 8.2 million (13 per cent) of all
deaths are cancer related
In Canada, what is the leading cause of death? What percentage does this account for?
> In Canada, cancer is the leading cause of death, accounting for 30 per cent of all deaths each year
Over the past 30 years the number of new cases diagnosed and cancer-related deaths have increased, mainly due to what? Are incidence rates stable? Are mortality rates decreasing? Are survival rates changing?
> due to the growth of the aging population (CCS, 2016).
> However, incidence rates are becoming stable or increasing only modestly, and mortality rates are decreasing, suggesting that survival rates are improving for some cancers
What are the three most common cancers in North America?
LPB
> lung, prostate, and breast
What is the most common cancer world wide? What is the most common cause of cancer death in the world?
> Lung cancer is the most common cancer worldwide, accounting for 13 per cent of all cancer cases
> lung cancer is the most common cause of cancer death in the world
- When did incidence & mortality rates decrease for men and women?
- What have been the trends for incidence and mortality rates for lung cancer in men and women?
- Was there a lag in the rates? If so- what caused it?
- Which gender has higher rates?
- began to decrease in the mid-1980s for men but did not do so until the mid-2000s for women
- This lag is attributed to gender dif-ferences in smoking behaviour. *Decreased smoking for men in the 1960s’ but not for women until the 1980s.
- however, that men still have higher incidence and mortality rates of lung cancer than women*
What is the most commonly diagnosed cancer among North American men?
> prostate cancer is the most commonly diagnosed cancer among North American men
Is prostate Cancer a leading cause of death in NA?
(In Canada and the US)?
> In Canada, prostate cancer is the third leading cause of cancer death
in the United States it is the second leading cause
What is the survival rate for lung cancer when it is localized? What percentages of diagnoses are made at this stage (localized)?
> the survival rate is 55 per cent when the cancer is localized, but unfortunately only 16 per cent of lung cancer diagnoses are made at this early stage
- What is the five-year survival rate for prostate cancer in the US and Canada for all type combined?
- Does the rate every reach 100% (if so what causes it)?
- What percentage of this type of cancer is spotted in the local or regional stages?
- the five-year survival rate for all stages of prostate cancer combined is between 95 per cent in Canada and 99 per cent in the United States
- This rate becomes 100 per cent when the cancer is localized
- 92 per cent of prostate cancers are discovered in the local or regional stages.
What are the incidence rates for prostate cancer (have they increased/fluctuated/decreased? Since what year if they have?
What are the mortality rates for prostate cancer? What year did the rates change?
> Incidence rates have fluctuated due to increased rates of cancer screening but have generally decreased since the early 2000s in both Canada and the United States.
> Mortality rates have also decreased since the mid-1990s because of the improved effectiveness of treatment.
What is the most common diagnosed cancer among women and north american women specifically? How many cases were reported in 2012?
> Around the world, breast cancer is the most diagnosed cancer among women, with an estimated 1.67 million cases diagnosed in 2012
> Breast cancer is also the most commonly diagnosed cancer among North American women
What percentage of cancer diagnoses does breast cancer account for? Is it a common cause of cancer death for North american women?
> Breast cancer accounts for approximately 26 to 29 per cent of all cancer diagnoses
it is the second-most common cause of cancer death among women in North America
- What is the survival rate of breast cancer across all stages of the disease for five years after diagnosis in Canada and the US?
- What is the rate for localized cancer?
- What is the rate for cancer that has spread?
- What percentage of breast cancer is localized?
- 87 per cent of Canadian women and 89 per cent of American women survive at least five years after diagnosis
- this rate is as high as 99 per cent when the cancer is localized
- is 85 per cent when the cancer has spread to surrounding regions
- 61% of breast cancer is localized.
- Have the incidence rates for breast cancer remained stable? Since what year (if they have)?
- When has mortality from breast cancer decreased and why has it decreased?
> Incidence rates have generally remained stable since the early 2000s
mortality from breast cancer has generally decreased since the mid-1980s thanks to early detection and more effective adjuvant therapy after surgery.
Treatment for cancer involves procedures that address cancerous cells locally, such as:
> surgery and radiation, and treatments, such as chemotherapy, that eradicate cancerous cells that may have metastasized to other areas of the body where they may develop into secondary tumours.
What is the purpose of surgery in cancer treatment? *Why do they extract tumors?
> Sur-gical removal of tumours allows them to be examined further by a pathologist to determine how aggressive they may be and whether they are likely to respond to particular types of adjuvant treatment.
How many types of Cancer drugs are there?
> over 250.
What is chemo used for and how can it be used when it is not the main intervention?
> Chemotherapy may be given as intravenous infusions or taken orally as pills.
> Some-times chemotherapy is administered to shrink a tumour before surgery, or even pal-liatively, to alleviate symptoms associated with a tumour’s growth.
What makes the determination of the cause of cancer a challenge?
> the long delay between exposure to risk fac-ors, such and the onset of cancer
Does cancer share clinical characteristics? (Do they vary?)
> Although different can-cers share similar clinical characteristics, the causes and risk factors associated with cancers at different sites varies.
cancer is often the result of the interaction of various risk factors, which can include what factors/agents?
> genetic factors,
environmental factors,
infectious agents,
behavioural factors, and
sociodemographic factors.
- Genetically, which people are at a heightened risk for developing cancer?
- What type of mutations cause cancer?
- What aspect of family history causes cancer?
- People who carry cancer gene mutations are at a heightened risk of developing cancer.
- can be because of inherited genetic mutations, although most cancers are due to sporadic mutations acquired during the lifespan.
> In addition, a family history of cancer, specific-ally in first-degree relatives, can confer increased risk; (they share genetics + lifestyle factors).
Exposure to certain environmental factors that are carcinogens can increases the risk of cancer development? What 4 types cause an increrased risk?
> asbestos, radon, and formaldehyde, can increase the risk of some can-cers
> Exposure to ionizing radiation, such as ultraviolet radiation (the principal cause of skin cancer), can increase cancer risk through damaging DNA.
Approximately 9.2 per cent of cancers in developed countries are attributable to infectious agents, including:
Related to sexual diseases-
> Helicobacter pylori, human papillomavirus (HPV), and hepatitis B (Plummer et al., 2016).
What percentage of cancer deaths are related to lifestyle choices?
> 35%
What are the main lifestyle choices that increase the risk of Cancers?
> tobacco use
smoking
high alcohol consumption, a diet low in fruits and vegetables, lack of exercise, and obesity
How does age affect the risk of developing Cancer? Why does incidence change?
> the incidence of cancer generally increases with age
the increased risk with age may be due to a combination of risk factors, including an accumu-lation of genetic mutations, a weaker immune system, and more carcinogen exposure
When age is controlled for, do men have higher rates of incidence for cancer than women?
> When age is taken into account, men generally have higher cancer incidence and mortality rates than women