BPK140: Contemporary Health Issues - Unit 5: Cancer

Comprehensive practice flashcards covering basic cancer biology, epidemiology, risk factors, types of cancer, screening, diagnosis, and treatment modalities from BPK140 Unit 5.

According to Statistics Canada data from $2012$, what was the leading cause of death for both sexes combined, and what percentage of all deaths did it account for?

Malignant neoplasms (cancer), which caused $74,361$ deaths ($30.2\%$ of total deaths).

What were the top three leading causes of death in Canada for both sexes in $2012$?

1. Malignant neoplasms (cancer) ($30.2\%$)\n2. Diseases of heart ($19.7\%$)\n3. Cerebrovascular diseases (stroke) ($5.3\%$)

Based on $2010$ Canadian data, what is the lifetime probability of developing cancer for males and females?

Males have a $45\%$ probability ($1$ in $2.2$), and females have a $42\%$ probability ($1$ in $2.4$).

Based on $2010$ Canadian data, what percentage of men and what percentage of women are expected to die from cancer?

$29\%$ of men and $24\%$ of women.

How is cancer defined?

The abnormal uncontrolled multiplication of cells due to genetic (DNA) mutations that disrupt the cell cycle.

What is the primary difference between benign and malignant tumours?

Benign tumours do not spread, whereas malignant tumours spread and can be life-threatening.

how do malignant tumours spread?

can invade blood or lymphatic vessels

What is cancer metastasis?

The process where malignant tumour cells invade blood or lymphatic vessels, travel to distant sites, and establish secondary tumours throughout the body.

In tumour development, what occurs during the hyperplasia stage?

An altered cell and its descendants look normal but continue to reproduce too much and proliferate.

In tumour development, what occurs during the dysplasia stage?

Following additional mutations, the descendants of the altered cells become abnormal in shape (which may or may not develop into cancer).

What characterizes in situ cancer?

Abnormal cells become more abnormal in shape and behaviour, but remain strictly confined to the location where they first formed.

What defines a localized invasive tumour?

Abnormal cells gain the ability to invade nearby tissues, but have not yet spread beyond the boundaries of the organ of origin.

What molecular mechanism normally regulates cell division to prevent cancer formation?

Proteins that control the cell cycle by performing checks before division is permitted to occur.

what are the stages of tumour development?

1. cells divide too much - hyperplasia

2. with more reproduction there can be more mutation, altering shape - dysplasia

3. cells may become more abnormal in shape and behavior, at first local - in situ cancer

4. abnormal cells may gain ability to invade nearby tissue - localized invasive cancer

5. sheds into blood or lymph and established tumours elsewhere - metastasis

What are four specific chemical carcinogens named in the lecture?

Benzene, aflatoxins, nickel, and ethanol.

Which two infectious pathogens are listed as direct causes of cancer in the notes?

Human papillomavirus (HPV) and Helicobacter pylori (H. pylori) bacterium.

How do blood cancers like leukemia differ from typical cancers in tumour production?

Blood cancers do not produce solid tumours, but they share the same fundamental property of uncontrolled cellular multiplication.

How can physical tumours (benign or malignant) cause harm or damage to the body?

They can block a blood vessel, compromise a nerve, or otherwise interfere with normal organ and body function.

How do advanced tumours with an established blood supply negatively impact healthy cells?

They consume critical supplies of energy and nutrients meant for healthy cells.

What were the top three projected cancer types by incidence for Canadian males in $2017$?

1. Prostate ($20.7\%$)\n2. Colorectal ($14.5\%$)\n3. Lung and bronchus ($14.0\%$)

What were the top three projected cancer types by incidence for Canadian females in $2017$?

1. Breast ($25.5\%$)\n2. Lung and bronchus ($13.8\%$)\n3. Colorectal ($11.5\%$)

Why are non-malignant skin cancers excluded from cancer incidence ranking statistics?

Nearly all non-malignant skin cancers are cured, so they are not included.

What is the rarest but most deadly form of skin cancer?

Malignant melanoma.

How much more common is melanoma in light-skinned (white) individuals compared to others?

Melanoma is $20\text{ times}$ more common in light-skinned individuals.

What quantity or type of moles is considered a significant risk factor for melanoma?

Having $200+$ moles (or $50+$ moles if under age $20$), or having atypical moles.

What does the ABCDE mnemonic stand for when identifying melanoma?

A: Asymmetry

B: Border (irregular, ragged, imprecise)

C: Colour (colour variation within lesion)

D: Diameter (usually $>6\,\text{mm}$)

E: Evolution (change in colour, size, shape, or symptom like itching, tenderness, bleeding)

What diagnostic imaging procedure is demonstrated in this image to detect a breast tumour?

A mammogram (mammography).

What are the major risk factors for breast cancer identified in the lecture?

Age, genetics, age at onset of menstruation (menarche), and lifetime exposure to estrogen.

What is the survival rate for breast cancer if detected early?

Greater than $80\%$ ($>80\%$).

By what pathway does breast cancer commonly metastasize?

Via lymph nodes close to the breasts.

What is the oldest type of cancer treatment, and what tissues are often removed when treating breast cancer?

Surgical removal (surgical excision);

the tumour and adjacent lymph nodes are often removed (e.g., via lumpectomy or mastectomy).

What is the leading mortal cancer (cause of cancer death) in Canada?

Lung cancer.

What is the $5$-year survival rate for lung cancer, and why is it so low?

Less than $20\%$ ($<20\%$), because there is no effective screening, symptoms appear only in later stages, and it is typically caught too late.

How does the lung cancer risk of non-smokers compare to that of smokers?

The risk for non-smokers is $5\text{--}10\%$ that of smokers.

What is the early detection survival rate for prostate cancer?

Approximately $95\%$ ($\sim 95\%$).

What are the two primary screening methods used for prostate cancer, and at what age is regular screening recommended?

Digital rectal exam (DRE) and prostate-specific antigen (PSA) test, recommended starting at age greater than $50$ ($>50$).

what are the risk factors of prostate cancer?

age, obesity, physical inactivity, history of STIs;

(possibly) diets with excess animal fats, low plant matter

symptom of prostate cancer

changes in urinary frequency or flow

prostate cancer treatment

• surgery to remove prostate

• radiation, cryotherapy, drugs

What marks the initial development of colorectal cancer?

Polyps in the intestine.

In which age demographic has the incidence of colorectal cancer been unexpectedly increasing?

Young adults in their $20\text{s}$ and $30\text{s}$.

colorectal cancer risk factors?

older age, male, IBS/IBS in family, obesity, smoking, alcohol abuse, eating red/processed meats

symptoms of colorectal cancer

• Change in bowel movements

• Pain/tenderness in abdomen

• Blood in feces

how is colorectal cancer tested for? when?

-Can be detected with endoscopic techniques such as colonoscopy and sigmoidoscopy

• Fecal blood screening is recommended (age >50)

where is the prostate gland

near the bladder

where is the cervix

btwn uterus and vagina

At what age does the British Columbia schedule mandate the first HPV vaccination for females and males?

Age $11$.

what is the leading risk factor of cervical cancer

HPV, human papilloma virus

at which age are HPV vaccines recommended

9-26

Why must females who have received the HPV vaccine continue to get regular Pap tests?

Because HPV vaccines only protect against some types of HPV, not all cancer-causing strains.

how is HPV transmitted

by skin-skin contact (not just sexual intercourse)

• Condoms NOT as effective in preventing transmission

high risk vs low risk HPV

high risk causes cancer

low risk causes plantar or genital warts

What is the fundamental difference between cancer screening and diagnostic testing?

Screening involves general exams on apparently healthy populations to detect potential disease;

testing involves more specific, invasive, and costly procedures (such as biopsies) on those suspected of having disease.

• biopsy: removal of tissue for further examination

According to the lecture, what proportion of cancers can be prevented, and what percentage are attributed to environmental factors?

Approximately half ($\sim 50\%$) can be prevented, and approximately $80\%$ ($\sim 80\%$) are caused by environmental factors.

what are the types of cancer treatments

1. Surgical removal

2. Chemotherapy

3. Radiation therapy

4. Immunotherapy

5. Gene therapy

6. Hormone therapy

what is chemotherapy

• Use of drugs to target and kill cancer cells

• An option when cancer may have spread

affects all cells/ can also impact healthy cells, leading to side effects like fatigue, nausea, hair loss

what is radiation therapy?

Beams are focused from several directions resulting in a higher dose at the tumour to kill cancer cells

• useful for localized tumours

• radiation damages DNA, can also kill healthy cells and side effects

• often used in combo w surgery or chemo

what is immunotherapy

Stimulating the immune system with drugs, giving immune system components

preventative vaccines available for HPV and HepB

treatment vaccines for prostate cancer to boost immune response

what is hormone therapy

Drugs that block hormone receptors or lower hormone levels

• Effective against cancers that are helped by hormones (e.g. breast, prostate, ovarian cancer)

modifiable ways to prevent cancer

• Don’t smoke, avoid second-hand smoke

• Reduce exposure to carcinogens

– e.g., UV light, radiation, asbestos, acrylamide

• Cancer-smart nutrition

– ↑ antioxidant-rich fruits & vegetables (e.g., vit C, D, folate);

reduce fat; don’t eat burnt BBQed foods; limit alcohol intake; keep a healthy weight

• Receive available vaccinations (e.g. HPV)

• Get screenings for early detection (secondary prevention)