Briefly

• Hormone replacement therapy reduces risk of colon cancer.
• Smoking before age 30 increases chances that colon cancer will recur.
• Low CEA levels improve both survival and disease-free survival for stage II colon cancer.
• Most patients want videos of their colonoscopies and are willing to pay for them.

Use of hormone replacement therapy reduces colon cancer

Women in a study of California teachers who were taking hormone replacement therapy (HRT) after menopause had a 36 percent reduced risk of colon cancer over ten years than women who weren’t on HRT at the beginning of the study.  Risk reduction was even greater for women with a first-degree relative who had colon cancer.  Their risk fell 55 percent.

Over 57,000 women were part of the study, about 60 percent of them on HRT at the study start.  Over the next ten years, 444 got colon cancer.

Despite the reduction in colon cancer in the study, doctors caution women about using HRT because of raised risks for breast cancer, heart attack, stroke, and blood clots.  Advice is to use the lowest dose for the shortest time to offset severe menopausal symptoms.

Katherine DeLellis Henderson, PhD, reports the study results in the February 15, 2010 issue of the American Journal of Epidemiology.

Early smoking history reduces disease-free survival after colon cancer

Patients with stage III colon cancer who had a smoking history of 12 or more pack years before they were 30 had almost a 40 percent increased risk of having their cancer return within three years compared to patients who had never smoked.

Among the 1,045 study participants, 46 percent had never smoked, 44 percent were past smokers, and 10 percent were currently smoking.

Disease-free survival three years after treatment was about 18 percent greater for people who had never smoked than for past smokers.

The results, based on questionnaires filled out by patients in the CALGB 80893 adjuvant chemotherapy trial, were published by Nadine Jackson McCleary, MD, MPH,and her colleagues in Cancer, February 15, 2010. They wrote,

Total tobacco usage early in life may be an important, independent prognostic factor of cancer recurrences and mortality in patients with stage III colon cancer.

CEA levels before surgery important for stage II prognosis

Patients whose CEA (carcinoembryonic antigen) blood levels before surgery were low — below 5 ng/ml — had significantly better overall and disease free survival than those whose CEA’s were 5 or higher.  For those with low CEA, overall survival at five years was 81.7 percent compared to 69.9 percent for high CEA.  Disease-free survival was 82.4 percent for low CEA and 70.6 percent for CEA that was 5 ng/ml or higher.

However, CEA levels only made a difference in stage II patients.  There was no significance for stage I or III.

Writing in the Journal of Surgical Oncology, Korean surgeon Jung Wook Huh, MD and colleagues concluded,

Preoperative serum CEA is a reliable predictor of recurrence and survival after curative surgery in patients with colon cancer, particularly in those classified as having stage II disease.

Patients want videos of their colonoscopies

Eight out of ten patients having colonoscopies said that they would like to have a video recording of their colonoscopy, and more than 6 of 10 (63 percent) were willing to pay for it.  After reading a brief paragraph explaining missed lesions during colonoscopy, over half (54 percent) were more interested in a video and none were less interested.

Meghana Raghavendra surveyed 248 outpatients at the Indiana University School of Medicine and reported the results in the World Journal of Gastroenterology, in an early online article January 28, 2010.

Women in Israel who used hormone replacement therapy (HRT) during and after menopause had about a 63 percent reduced risk of getting colon or rectal cancer.

However, those women who were active in sports or who took aspirin regularly didn’t benefit from HRT.

As part of the Molecular Epidemiology of Colorectal Cancer (MECC) study, researchers questioned 2,400 Northern Israeli women with colon or rectal cancer about their use of hormone replacement therapy, using either pills or patches.  They matched the women with cancer to a control group with similar backgrounds.

They also asked about use of aspirin, statins, and non-steroidal anti-inflammatory drugs (NSAIDS).  Women answered diet and exercise questions, including whether or not they ate 5 or more vegetables daily or took part in sports.

Women with at least one first degree relative who had been diagnosed with colorectal cancer were listed as having a family history.

Reduction in risk remained the same between women with and without familycolorectal cancer history, those who ate more vegetables and those who didn’t, women with normal weight and obese women, and users and nonusers of statins.

There was a stronger advantage to using hormone replacement therapy for women who were sedentary.

However, women who were daily aspirin users and also took hormone replacement therapy had an increased risk of colorectal cancer.

Women who used HRT and took part in sports had no advantage from HRT, but also did not have an increased risk.

Even after adjusting for known risk factors for colorectal cancer – age, use of aspirin/NSAIDs, use of statins, vegetable consumption, sports activity — using hormone replacement therapy continued to have a significant effect in reducing the risk of colorectal cancer in this group of women.

Significantly, only the use of combined estrogen/progestin HRT in pill form reduced colorectal cancer risk.  Estrogen alone or HRT patches did not.

Writing in the Journal of Clinical Oncology, Gad Rennert, MD, and his team concluded,

The use of oral HRT was associated with a 63% relative reduction in the risk of colorectal cancer in postmenopausal women after adjustment for other known risk factors. This effect was not found in aspirin users and women with intensive sports participation.

SOURCE: Rennert et al, Journal of Clinical Oncology, published online ahead of print, August 24, 2009.

What This Means for Patients

Although use of hormone replacement therapy reduces risk for colorectal cancer in this study, other research has found that HRT increases risk for cardiovascular disease and breast cancer.

Combining daily aspirin and hormone replacement therapy may increase your risk for colorectal cancer, and if you are very active in sports, you may not have any further benefit from HRT.

Discuss your personal and family risks for heart disease, breast and ovarian cancer, and colorectal cancer in deciding how to use hormone replacement therapy.