Frequently Asked Questions about Estrogen plus progestin and colorectal cancer
These questions and answers supplement the March 3, 2004 New England Journal of Medicine publication on E + P and colorectal cancer.
- What were the main findings from the estrogen plus progestin and colorectal cancer analyses?
- What was the decreased risk for women taking estrogen plus progestin for colorectal cancer?
- What were the conclusions from these findings?
- What is colorectal cancer?
- What is invasive colorectal cancer?
- What tests can detect colorectal cancer?
- What happens to colorectal cancer risk after E+P use is discontinued?
- What type of hormone treatment did women in the E+P study take?
- What happens with colorectal cancer risk in women taking estrogen alone (without progestin) or other E+P formulas?
- Should I discuss this information regarding colorectal cancer with my healthcare provider?
- What are the symptoms of colorectal cancer?
- I am taking prescription hormones. What shall I do?
1. What were the main findings from the estrogen plus progestin and colorectal cancer analyses?
Answer: Fewer women who took estrogen plus progestin (E+P) developed colorectal cancer than women taking placebo (inactive pills). The cancer cases found in women taking E+P had similar characteristics (looked the same under the microscope) but the tumors had spread more throughout the body than those in the placebo group.
2. What was the decreased risk for women taking estrogen plus progestin for colorectal cancer?
Answer: A woman was less likely to develop colorectal cancer if she was taking E+P. For every 10,000 women taking estrogen plus progestin, six fewer women will develop colorectal cancer while taking estrogen plus progestin.
While reducing the risk developing the risk of developing colorectal cancer is favorable, the colorectal cancer cases which developed in women taking E+P were more advanced; about 76% had spread to lymph nodes or elsewhere in the body, compared to 49% of women on placebo.
3. What were the conclusions from these findings?
Answer: Use of E+P decreases the rate of total colorectal cancers compared with placebo but the colorectal cancers which developed on E+P were diagnosed at a more advanced stage. Routine screening for colorectal cancer was not a part of the Women’s Health Initiative study. Therefore, we do not know if routine screening for colorectal cancer either looking for blood in the stool (Hemoccult, Guaiac testing) and/or examining the colon and rectum using sigmoidoscopy and/or colonoscopy could have discovered the colorectal cancers developing on E+P at an earlier stage.
4. What is colorectal cancer?
Answer: Cancer is a disease in which abnormal cells divide without control and can spread to other parts of the body. The colon and rectum are part of the large intestine (large bowel). Colon and rectum cancers which are sometimes referred to together as “colorectal cancer” arise from the lining of the large intestine. When cancer arises from the lining of an organ like the large intestine it is called a carcinoma. Other types of colon cancer are rare and include lymphoma, carcinoid tumors, melanoma, and sarcomas. Use of the term colon cancer throughout this question and answer section refers to colon “carcinoma” and not the other rare types of colon cancer.
5. What is invasive colorectal cancer?
Answer: Invasive colorectal cancer involves abnormal cells from the colon or rectum which can invade nearby tissues and can spread to other parts of the body.
6. What tests can detect colorectal cancer?
Answer: Fecal occult blood test: (FOBT) is used to find occult “hidden” blood in the stool if FOBT detects blood in the stool additional testing is needed to determine the cause of the bleeding. Certain foods and drugs can also influence test FOBT test results. For this test a kit with instructions is usually given that explains how to take the stool samples at home (usually 3 specimens). The kit is then returned to the doctor’s office or medical laboratory for testing.
Sigmoidoscopy: A sigmoidoscope is a slender, flexible, hollow lighted tube which is inserted through the rectum into the lower part of the colon. Because of its limited length of around 2 feet only the lower half of the colon is visualized.
Colonoscopy: A colonoscope is a long version of a sigmoidoscope is inserted through the rectum and allows visualization of the entire lining of the colon.
Other tests which could be considered including barium enema with air contrast and “virtual” colonoscopy available at some centers.
7. What happens to colorectal cancer risk after E+P use is discontinued?
Answer: WHI researchers will be looking at these issues in future analyses so the information is not yet available.
8. What type of hormone treatment did women in the E+P study take?
Answer: Women randomized (assigned by chance) to active hormones were taking one tablet containing conjugated equine estrogens 0.625 mg and medroxyprogesterone acetate (2.5 mg) each day (Prempro?). When the WHI study first begun, this was the most commonly prescribed menopausal hormone therapy in the United States for women with the uterus.
9. What happens with colorectal cancer risk in women taking estrogen alone (without progestin) or other E+P formulas?
Answer: The current report addresses only the issue of E+P use in the form of pills. Final results from the ongoing estrogen alone (E alone) study are unknown at this time. Participants in the E alone study are asked to continue to take the study pills and to come for the regular clinic visits. The National Heart, Lung and Blood Institute which overseas WHI, continues to review the study for women receiving E-alone and they will provide investigators and participants with any new information about the study that might affect their participation.
10. Should I discuss this information regarding colorectal cancer with my healthcare provider?
Answer: Yes. Your healthcare provider may read the scientific paper in the January issue of the New England Journal of Medicine or you may direct your provider to this website. Your provider may also want to speak with your local WHI Principal Investigator about these results.
11. What are the symptoms of colorectal cancer?
Answer: Symptoms that could be associated with colorectal cancer include a change in bowel habits such as constipation, diarrhea, or narrowing of the stool that lasts for more than a few days; cramping or steady abdominal (stomach area) pain; weakness and fatigue; rectal bleeding or blood in or on the stool; or a feeling of having to have a bowel movement that is not relieved by doing so.
Since other conditions can cause these symptoms, a medical work up is needed. Also colorectal cancer may have few or no early symptoms.
12. I am taking prescription hormones. What shall I do?
Answer: Talk with your healthcare provider about your individual risk profile and hormones you are taking in light of the WHI results.