Cancer Flashcards
Which 4 cancers have the highest diagnosis rates in Canada?
Lung, breast, prostate, and colorectal cancers.
Which 3 cancers account for the most deaths in Canada?
Lung, colorectal, and breast cancers.
Which 2 cancers are less common but have high mortality rates?
Liver and pancreatic cancers.
What is cancer, and what causes it?
Cancer is uncontrolled cell growth caused by genetic mutations and epigenetic alterations that lead to metastasis.
What happens during the initiation stage of carcinogenesis?
A carcinogen causes mutations in DNA. If the DNA is not repaired or the cell does not undergo apoptosis, the mutation persists. This stage lasts minutes to days.
What occurs during the promotion stage of carcinogenesis, and how long does it last?
Mutated DNA alters gene expression, leading to uncontrolled cell proliferation. This stage may last months or years. Promoters (e.g., alcohol, estrogen, Helicobacter pylori, HPV) increase risk but don’t guarantee cancer
What defines the progression stage of carcinogenesis?
Malignant cells invade surrounding tissue and metastasize to other parts of the body, forming malignant tumors.
What is a malignant tumor, and how does it spread?
A malignant tumor invades neighboring tissues, enters blood vessels, and metastasizes to other body sites.
How does a benign tumor differ from a malignant tumor?
A benign tumor grows locally and does not spread by invasion or metastasis but can still affect surrounding tissues.
What are tumor suppressor genes, and how do they prevent cancer?
Tumor suppressor genes, like BRCA1 and BRCA2, repair DNA damage and regulate cell growth. Loss of these genes can lead to cancer.
What are oncogenes, and how do they contribute to cancer?
Oncogenes are mutated proto-oncogenes that drive uncontrolled cell growth. These genes are usually silenced after embryogenesis but can reactivate through mutations.
How do genetic and epigenetic alterations contribute to cancer?
Genetic alterations: Mutations in key genes impair DNA repair and cell cycle regulation.
Epigenetic alterations: Changes in DNA methylation and histone modification affect gene expression, silencing tumor suppressor genes or activating oncogenes.
What role does SAM play in DNA methylation, and how is it influenced by nutrition?
SAM (S-adenosylmethionine) is a methyl donor for DNA methylation, requiring dietary nutrients like folate, choline, and B vitamins. Poor nutrition can reduce SAM availability and disrupt methylation.
What are examples of bioactive compounds that influence cancer prevention?
Resveratrol (grapes)
Sulforaphane (broccoli)
Pterostilbene (blueberries)
These compounds can reverse DNA methylation changes, activate tumor suppressor genes, and silence oncogenes.
What are the 4 functional benefits of nutrients and bioactive compounds in cancer prevention?
Reduce cell proliferation and invasiveness.
Inhibit oncogenic signaling pathways.
Prevent oxidative DNA damage.
Detoxify carcinogens and reduce inflammation.
What evidence links obesity to cancer?
Obesity is convincingly associated with increased risk of colorectal, kidney, and pancreatic cancers, as well as postmenopausal breast cancer.
How does physical activity affect cancer risk?
Convincing evidence shows physical activity reduces the risk of colon cancer.
What is the relationship between processed meat consumption and cancer?
Processed meat is classified as a Group 1 carcinogen and is convincingly linked to increased colorectal cancer risk.
How does dietary fiber reduce colorectal cancer risk?
Speeds gut transit time.
Binds carcinogens in the gut.
Alters gut flora and produces protective short-chain fatty acids.
What types of cancers are linked to alcohol consumption?
Convincing evidence links alcohol to cancers of the mouth, esophagus, liver, colorectal area, and postmenopausal breast cancer.
What are the benefits of consuming fruits and vegetables for cancer prevention?
Probable evidence suggests non-starchy vegetables and fruits reduce the risk of aerodigestive cancers.
How does beta-carotene supplementation affect lung cancer risk in smokers?
High-dose beta-carotene supplements increase lung cancer risk by protecting cancer cells from oxidative stress.
What evidence links calcium to cancer prevention?
Probable evidence suggests calcium supplements reduce colorectal cancer risk, but high dietary calcium intake may increase prostate cancer risk.
How do sugary beverages influence cancer risk?
Limited-suggestive evidence links sugary beverages to pancreatic cancer, with higher risks due to obesity.
