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A healthy lifestyle and regular screening help fight colon cancer
March is Colorectal Cancer Awareness Month and you are empowered to reduce the risks of getting colorectal cancer, commonly called colon cancer.
"Excessive alcohol has also been associated with an increased risk of colorectal cancer," says Song Kang, a radiation oncologist with Virginia Oncology Associates. "In addition, these lifestyle changes have benefits in reducing the risk of other cancers and chronic diseases."
- Maintain a healthy body weight.
It's also important to maintain screening tests such as digital rectal exams, tests for blood in the stool and colonoscopies; if colorectal cancer does develop, it can be found in the earliest stages possible, maximizing the chance for cure.
Colorectal cancer signs and symptoms include abdominal pain, bleeding, change in bowel habits, weakness or other manifestations of anemia -- and sometimes weight loss. Screening tests such as colonoscopy (a fiber optic viewing tube), testing for occult blood or barium enema can lead to a diagnosis before symptoms and can improve survival by finding disease at an earlier stage.
Diagnosis is made usually at the time of a colonoscopy. This procedure allows a biopsy, or removal of a small piece of the tumor, which is needed to make a diagnosis. After diagnosis, there's a CT scan or less commonly used PET scanning to estimate the extent of disease. More is known when the surgeon removes regional nodes and a pathologist examines them microscopically.
Treatment is usually surgery. For early stage colorectal cancers, surgery may be all that's necessary. Several improvements in surgery have occurred recently. The use of laparoscopic techniques leads to more rapid recovery; stapling devices allow resection of an increased number of low rectal tumors without the need for a colostomy. Characteristics of the cancer and location sometimes require complete removal of the rectum and a colostomy as the best option for cure and good patient hygiene. For colon cancer, chemotherapy is often recommended after surgery, depending on the extent of disease and lymph nodes involved. Radiation therapy is typically not used in the treatment of colon cancer unless it is very advanced locally, or if the cancer could not be completely removed by surgery.
When rectal cancer is advanced, the treatment strategy usually employs a combination of radiation and chemotherapy prior to surgical removal, followed by several months of additional chemotherapy. While chemotherapy travels throughout the body, the radiation is very focused on the region of the tumor and the lymph nodes in the pelvis. This allows concentrated treatment to the area to maximize shrinkage of the tumor, and to kill cancer cells in the lymph nodes at highest risk for spread. Shrinking the tumor with radiation prior to surgery allows the tumor to be removed optimally. The radiation and chemotherapy are sometimes given after surgery if the lymph nodes are found to be involved with cancer or the tumor is more extensive than initially thought. The goal of radiation after surgery is to sterilize any remaining cancer cells in the tumor bed and/or in the lymph nodes. Radiation treatments involve daily treatments that last approximately 10-15 minutes, for about five and a half weeks. Radiation is an X-ray treatment, so the patient does not feel anything during the actual treatments.
When colon cancer spreads, chemotherapy is used to shrink the cancers throughout the body, and focused patches of radiation are used for localized problems caused by the tumors. Newer techniques of radiation can now be used to treat CRC that has spread to the liver. These may involve highly focused beams of radiation, or injection of microscopic radiation spheres that target the liver.
In some low rectal cancers, the surgical treatment may require a colostomy bag in order to remove the entire tumor. A colostomy is a hole that is made in the abdomen for the stool to be collected into a bag if the anus needs to be surgically closed. Despite the initial impressions, most patients with colostomy bags do extremely well and are able to carry on with an excellent quality of life.
Survival rates continue to improve, in all stages compared with even a few years ago. Reasons for this improvement include better surgical technique and more effective post-operative chemotherapy. For early-stage cancer, cure rates are in excess of 90 percent; for those with regional lymph node involvement, survival exceeds 70 percent at five years.
Even in metastatic disease, the median survival rate (the time point when half of the original study group is still alive), has increased from six months to two years, a four-fold increase, which is impressive.
Newer agents, such as the blood vessel formation inhibitor, Avastin, aid traditional chemotherapies. More studies on individual tumor characteristics, such as gene mutations, help targeted therapy fight the cancer.
Genetic counseling is offered for people at an increased risk for hereditary color cancer syndrome. The personal and family history is evaluated in detail, and recommendations are made regarding genetic testing.
The incidence starts to rise significantly after age 40 to 50; about 90 percent are diagnosed after age 50, hence the recommendation to start surveillance colonoscopy.
Most patients do not have a positive family history or genetic predisposition. Risk increases 5 to 15 fold by inflammatory bowel disease such as ulcerative colitis and Crohn's disease.
Other less well- proven risk factors are alcohol intake, cigarette smoking, diabetes and insulin resistance, obesity and red meat consumption.
Some protective factors include exercise and increased activity levels, increased intake of dietary fiber, folic acid, and intake of aspirin or other anti-inflammatory agents. Exercise also appears to greatly reduce recurrence risk in patients treated for the disease.
If you worry about family history, talk to your healthcare provider about a referral for genetic counseling.
Sources: Medical oncologist John Kessler, radiation oncologist Song Kang and cancer genetic counselor Tifany Lewis, all with Virginia Oncology Associates