Basic Cancer Biology
Coursera~Johns Hopkins
I recently learnt some basic cancer biology from coursera, the link as below.
https://www.coursera.org/learn/cancer/lecture/XsshR/incidence-and-etiology-of-cancer
Lecture1~ Cancer Terms and Definitions
Cancer means “uncontrolled growth” => uncontrolled devision of abnormal cells in a part of the body
Also referred to as a “tumor” => a swelling of a part of the body, generally without inflammation, caused by an abnormal growth of tissue, whether benign or malignant
Also referred to as a “neoplasm” => a new and abnormal growth of tissue in some part of the body
So, cancer is caused by an accumulation of detrimental variation in the genome instead of single mutation
Where does the word from?
about cancer
- From Greek => “a crab” (because some tumors with swollen veins are similar to crabs )
- From Latin => “a crab” => “maglignant tumor”
- Old English => “spreading sore”
about Oncology
“onco” means bulk, mass or tumor => a study branch of tumor and cancer science
about Metastasis
From Greek => “migration; a changing; revolution”
Now refers to the spreading of cancer from primary site to distant organs
Where does cancer start?
Cancers are classified into four main types according to the tissues where they originate
Carcinoma: Arise in epithelial tissue (internal and external lining of the body)
Adenocarcinomas develop in an organ or gland; [Most common cancer including prostate, breast, liver cancer]
First look at the cervical histology
Then look at the Carcinoma (Prostate Cancer)
- Squamous cell carcinorma develop in the squamous epithelium of organs, including the skin, bladder, esophagus, and lung
Sarcoma: [Account for < 10% ]Arise from connective tissue that is found in bones, tendons, cartilage, muscle, and fat
This is Ewing’s Scarcoma
Leukemia: cancer of the blood that originate in bone marrow
Lymphoma: Cancers of the lymph system (starting from lymph node)
six most common cancers worldwide
The global cancer burden is estimated to have risen to 18.1 million new cases and 9.6 million deaths in 2018
Lung
- Function: Lungs deliver air(oxygen) to the blood
- Most common in men and women, extremely lethal
- Many subtypes, but 85% are non-small-cell cancers (NSCLC), including adenocarcinoma (40%), squamous cell carcinoma (25%) and large-cell carcinoma (10%)
- Risk factors: Smoking (87% in men and 70% in women) => 25 times higher risk compared to non-smokers
Breast
milk-producing glands surrounded by fat and connective tissue. The gland connect to ducts which carry milk out to the nipple
Most common cancer in US women; Second leading cause of cancer death
Classified by location and histologic ( tissue or cellular) subtype. 70% -80% are infiltrating ductal cancers, followed by lobular and nipple cancers
Risk factors: Age: 1/8 cancers in women under 45; 2/3 are in women over age 55;
Positive family history: Approximately double if having one first-degree relative (mother, sister, or daughter);
Genes: BRCA1 increase risk by 55-65%, BRCA2 by 45%; Dense breast tissue: may make mammograms less acurate Lifestyle: Obesity, inactivity, alcohol use, not having children, oral contraceptive use, post-menopausal hormone therapy
Prevention: No known proven strategies, except for prophylactic mastectomy in high-risk women
Screening: Self-exams, Yearly exams by health practitioner, Mammograms, MRI, ultrasound (potentially)
Colon
Five-foot-long tube at the end of the digestive system that store waste
Rectum is the last 6 inches of the colon
Third most common cancer
Most primary colon cancers are adenocarcinomas
Detected early => could be cured
Risk factors: Age (9/10 diagnosed people are over 50-year-old); Diet: High in red meats, low in vegetables; Lifestyle: Obesity, smoking, alcohol; Inflammatory bowel disease; Positive family history: Approximately double with one affected first-degree relative; Genes: DNA repair=> APC, KRAS, TP53
Colon cancer screening: Colonscopy every 5-10 years from age 50
Prostate
A gland about the size of a walnut below the bladder
Only found in men; Thought to protect the urinary tract from infections
Most common in men and as 2ed leading cause of cancer death
Risk factors: Age: mainly in old men (6/10 in age 65 or older; rare before age 40; average age is 66) Ethnicity: Higher in African American men, lower in Asian men Positive famoly history: Double when father or brother with cancer Genes: HoxB13; BRCA1,2; MSH2; MLH1 Diet: High in red meat, low in vegetables
Prevention: No known proven strategies
Screening: Yearly digital rectal exam starting at age 50; Yearly prostate-specific antigen (PSA) blood tests at age 55-69; African-americans or with + family history screen at age 40
Stomach
- Risk factors: Sex: twice in men; Age: over age of 60; H.pylori: Chronic infection with this bacteria Diet: smoked foods, salted fish/meat, pickled vegetables Lifestyle: Obesity, smoking Type A blood
Liver
- A large gland at right below the rib cage on the right side;
Process nutrients absorbed from the intestine;
Makes clotting factors;
Secretes bile to help absorb fats
- Risk factors: Sex: twice in men; Chronic viral hepatitis: HepB or HepC lead to cirrhosis of the liver; Alcohol: lead to cirrhosis Aflatoxins; Lifestyle: Obesity, anabolic steriods abuse, smoking
- Screening: No proven strategies Alpha-fetoprotein (AFP) blood tests and ultrasound exams every 6 to 12 months
- A large gland at right below the rib cage on the right side;
Process nutrients absorbed from the intestine;
Makes clotting factors;
Secretes bile to help absorb fats
