Psychosocial Issues

Psychosocial Issues

- financial: expensive to undergo surgeries; colostomy bags can be expensive; also to go for check ups (rectal examination, colonscopy, barium); genetic screening (?)

- emotional: have faced it before; saw how it affected his father; could cause him to not have faith in the modern interventions; either scares him to taking the treatments earlier or go for some other forms of treatments (CAM); could affect his children seeing their father, uncle and grandfather getting the disease; worried that they might get the disease as well; the need to go for check-ups can be traumatising; can affect his wife, not sure if her husband might be affected severely; how would she support the children

- socialising: if need to use colostomy bag, might not feel comfortable when being out with friends; feel inferior; passing gas and possibility of a bag blowout; could offend others if do not know how to handle the situation

- exercise/work: might feel reluctant to exercise if need to use the colostomy bag because it is inconvenient; could be jeered at by his students

- adapting to life: difficulty swimming and showering; may need to adjust his diet if using the colostomy bag; learning to deal with the smell from the stool

- social support: could join cancer patient support groups; colon cancer support groups (eg. colostomy association in UK)

(Posted by: Vivian)

Causes And Risk Factors for Colon Cancer

Cause of Colorectal cancer:

The exact cause of colorectal cancer is unknown.

Risk Factors

NB: Definitions: (Merriam Webster Medical Dictionary)

Predispose: To make susceptible.
Risk factor: Something which increases risk or susceptibility.

SO, what is the difference between a predisposing factor and a risk factors? Looks the same to me.

Anyway, these are some factors that increase a person's risk of developing the colorectal cancer:

Age. The risk of developing colorectal cancer increases as we age. The disease is more common in people over 50, and the chance of getting colorectal cancer increases with each decade.

Gender. The risk overall are equal, but women have a higher risk for colon cancer, while men are more likely to develop rectal cancer.

Polyps. Polyps are non-cancerous growths on the inner wall of the colon or rectum. Adenomatous polyps increase the risk of developing colorectal cancer.

Past Medical history. Research shows that women who have a history of ovarian, uterine or breast cancer have a somewhat increased risk of developing colorectal cancer. Also, a person who already has had colorectal cancer may develop the disease a second time. In addition, people who have chronic inflammatory conditions of the colon, such as ulcerative colitis or Crohn's disease, also are at higher risk of developing colorectal cancer. The risk for cancer begins to rise after eight to 10 years of colitis.

Family history. Parents, siblings, and children of a person who has had colorectal cancer are somewhat more likely to develop colorectal cancer themselves. If many family members have had colorectal cancer, the risk increases even more. A family history of familial polyposis, adenomatous polyps, or hereditary polyp syndrome also increases the risk.

Diet. A diet high in fat and calories and low in fiber may be linked to a greater risk of developing colorectal cancer. It is believed that the breakdown products of fat metabolism lead to the formation of carcinogens.

Lifestyle factors. You may be at increased risk for developing colorectal cancer if you drink alcohol, smoke, don't get enough exercise, and if you are overweight.

Diabetes. People with diabetes have a 30-40% increased risk of developing colon cancer.
(Read news article on CBS @ http://www.cbsnews.com/stories/2004/10/01/health/webmd/main646860.shtml)


Genetics and colon cancer

A person's genetic background is an important factor in colon cancer risk. Among first-degree relatives of colon cancer patients, the lifetime risk of developing colon cancer is increases threefold.

Even though family history of colon cancer is an important risk factor, majority (80%) of colon cancers occur sporadically in patients with no family history of colon cancer. About 5 % of colon cancers are due to hereditary colon cancer syndromes. Hereditary colon caner syndromes are disorders where affected family members have inherited cancer-causing genetic defects from one or both of the parents.

Chromosome damages cause genetic defects that lead to the formation of colon polyps and later colon cancer. In sporadic polyps and cancers (polyps and cancers that develop in the absence of family history), the chromosome damages are acquired. The damaged chromosomes can only be found in the polyps and the cancers that develop from that cell. But in hereditary colon cancer syndromes, the chromosome defects are inherited at birth and are present in every cell in the body. Patients who have inherited the hereditary colon cancer syndrome genes are at risk of developing large number of colon polyps, usually at young ages, and are at very high risk of developing colon cancer early in life, and also are at risk of developing cancers in other organs.

Contributed by John Lee

Sources:
http://www.medicinenet.com/colon_cancer/page2.htm
http://www.webmd.com/colorectal-cancer/guide/risk-factors-colorectal-cancer
http://www3.mdanderson.org/depts/hcc/
http://www2.merriam-webster.com/cgi-bin/mwmednlm

Pathophysiology of Colorectal cancer

Ji Keon LOOI

Polyps
•small protrusion on the end of a slim stalk
•can grow out of the membranes lining various areas of the body.
•grow either singly or in clusters.
•Mostly benign
•Most cases of colon cancer begin as small, non-cancerous (benign) clumps of cells called adenomatous polyps. Over time some of these polyps become colon cancers.
•Others: hyperplastic, inflammatory polyps

Colon Cancer and Polyp

Background of Colorectal Cancer
•Vast majority of colorectal cancers are adenocarcinomas – 95%
•Arises from preexisting adenomatous polyps that develop in the normal colonic mucosa
•Associated with discrete molecular genetic alterations
RevisionPathogenesis of cancer
•Tumour suppressor gene
•Oncogene

Properties of Cancer Cells:
•evading apoptosis
•self-sufficiency of growth factors
•increased cell division rate
•altered ability to differentiate
•ability to invade neighbouring tissues (metastasis)
•ability to promote blood vessel growth (angiogenesis)

Genetic Basis for Colon cancer
•Mutations of APC (adenomatous polyposis coli) gene
–familial adenomatous polyposis (FAP), and
–Sporadic colorectal cancer

•The protein encoded by the APC gene targets the degradation of beta-catenin, a protein component of a transcriptional complex that activates growth-promoting oncogenes, such as cyclin D1 or c-myc.

More about genetics of colon cancer
•Leads to imbalance in genomic DNA methylation
•global hypomethylation è oncogene activation
•regional hypermethylation è silencing of tumor suppressor genes
•Bcl2 over-expression è inhibition of cell death signaling (antiapoptotic)è colorectal cancer development

Familial adenomatous polyposis (FAP)
•autosomal dominant
•less than 1% of all colorectal cancers and has an incidence of 1 in 10,000
•presence of 100 or more tubovillous adenomas in the colon
•almost all of gene carriers have polyps by 40 yo. Untreated polyps è malignant transformation

Autosomal Dominant Inheritance

Attennuated Familial Adenomatous Polyposis
•a milder version of FAP
•less than 100 colon polyps
•autosomal dominant
•very high risk of developing colon cancers at young ages.
•Also at risk of gastric polyps and duodenal polyps

Hereditary non­polyposis colon cancer
•gene carriers will develop a small number of tubovillous adenomas, but not more than 100
•Mismatch repair genes
•Knudson’s two hit hypothesis
–Failure to repair mutations in tumour suppressor genes è adenoma carcinoma

•Also at risk of developing uterine cancer, stomach cancer, ovarian cancer, and cancers of the ureters, and the biliary tract
Colorectal Cancer

Thank you
•Any Questions?

Labelling our posts

To avoid confusion to differentiate between pcl materials from MED2031 and MED2042 since we start with Week 1 again this semester, I would suggest that we label our work according to the title of the week.

I have entered all the pcl titles under this post and they should appear when you type in the first letter into the label slot. Alternatively, click on Show all to display all the pcl title.

Thanks.

Ji Keon