Showing papers by "Cynthia A. Thomson published in 2003"

Influence of Estrogen Plus Progestin on Breast Cancer and Mammography in Healthy Postmenopausal Women: The Women's Health Initiative Randomized Trial

Abstract: ContextThe Women's Health Initiative trial of combined estrogen plus progestin was stopped early when overall health risks, including invasive breast cancer, exceeded benefits. Outstanding issues not previously addressed include characteristics of breast cancers observed among women using hormones and whether diagnosis may be influenced by hormone effects on mammography.ObjectiveTo determine the relationship among estrogen plus progestin use, breast cancer characteristics, and mammography recommendations.Design, Setting, and ParticipantsFollowing a comprehensive breast cancer risk assessment, 16 608 postmenopausal women aged 50 to 79 years with an intact uterus were randomly assigned to receive combined conjugated equine estrogens (0.625 mg/d) plus medroxyprogesterone acetate (2.5 mg/d) or placebo from 1993 to 1998 at 40 clinical centers. Screening mammography and clinical breast examinations were performed at baseline and yearly thereafter.Main Outcome MeasuresBreast cancer number and characteristics, and frequency of abnormal mammograms by estrogen plus progestin exposure.ResultsIn intent-to-treat analyses, estrogen plus progestin increased total (245 vs 185 cases; hazard ratio [HR], 1.24; weighted P<.001) and invasive (199 vs 150 cases; HR, 1.24; weighted P = .003) breast cancers compared with placebo. The invasive breast cancers diagnosed in the estrogen plus progestin group were similar in histology and grade but were larger (mean [SD], 1.7 cm [1.1] vs 1.5 cm [0.9], respectively; P = .04) and were at more advanced stage (regional/metastatic 25.4% vs 16.0%, respectively; P = .04) compared with those diagnosed in the placebo group. After 1 year, the percentage of women with abnormal mammograms was substantially greater in the estrogen plus progestin group (716 [9.4%] of 7656) compared with placebo group (398 [5.4%] of 7310; P<.001), a pattern which continued for the study duration.ConclusionsRelatively short-term combined estrogen plus progestin use increases incident breast cancers, which are diagnosed at a more advanced stage compared with placebo use, and also substantially increases the percentage of women with abnormal mammograms. These results suggest estrogen plus progestin may stimulate breast cancer growth and hinder breast cancer diagnosis.

Influence of Estrogen Plus Progestin on Breast Cancer and Mammography in Healthy Postmenopausal Women: The Women’s Health Initiative Randomized Trial

Abstract: The large-scale Women's Health Initiative has confirmed that, in postmenopausal women, combined estrogen/ progestin therapy entails an increased risk of invasive breast cancer. The investigators have now explored this relationship in detail, characterizing the cancers that developed and seeking to learn whether hormonal effects on the mammogram can influence diagnosis. A total of 16,608 postmenopausal women 50 to 79 years of age, all with an intact uterus, were randomly assigned to receive active treatment (0.625 mg conjugated equine estrogens plus 2.5 mg medroxyprogesterone acetate daily in a single tablet) or placebo. The participants, seen at 40 clinical centers, were to be followed from 1993 to 1998 by annual clinical breast examinations and mammograms, but the trial was ended after a mean interval of 5.2 years. Intent-to-treat analyses demonstrated a hazard ratio of 1.24 for both total cancers and invasive cancers in women given hormone therapy compared with the placebo group. There was some suggestion of an increased risk for in situ breast cancer in hormone-treated women. An increased risk of breast cancer in treated women emerged after 3 years in those not receiving hormones previously and after 2 years in previously treated women. The findings were similar when women in specific risk categories were analyzed, and race and ethnicity were not significant factors. Invasive cancers associated with combined hormone therapy were larger than those in placebo recipients, more likely to be node-positive, and diagnosed when more advanced. There was, however, no difference in tumor grade or in the distribution of histologic types of breast cancer. After the first year, hormone-treated women more often had abnormal or highly suspicious mammograms than did those given placebo. In this prospective, randomized trial, combined estrogen/progestin treatment of postmenopausal women increased both breast cancer risk and the frequency of abnormal mammograms requiring medical assessment. In addition, cancers in treated women were more advanced when diagnosed than was the case for placebo recipients.

Measuring Dietary Change in a Diet Intervention Trial: Comparing Food Frequency Questionnaire and Dietary Recalls

Abstract: Measurement of dietary change was assessed in a systematic quota subsample (n = 397) of women recruited into the Women's Healthy Eating and Living Study between 1996 and 1998, a multicenter, randomized dietary intervention trial among breast cancer survivors. Women from the intervention and comparison arms completed the Arizona Food Frequency Questionnaire (AFFQ) and 24-hour dietary recalls at baseline (prerandomization) and at year 1 (postrandomization). Both dietary measurement methods demonstrated significant changes in intake of key intervention-associated nutrients at year 1 in the intervention group subjects compared with minimal or no change in the comparison group subjects. The reliability of the AFFQ and recalls was measured in the comparison group and showed correlations of 0.63 and 0.43, respectively. Both instruments captured differences in dietary intake associated with the diet intervention. These results demonstrate the utility of using a multimode, multimethod approach (AFFQ and 24-hour dietary recalls) to measure differences in self-reported dietary intake over time as shown in this dietary intervention trial being conducted among breast cancer survivors.

Nutrition and diet in the development of gastrointestinal cancer.

Abstract: Diet plays a role in the prevention and development of gastrointestinal cancers. The majority of available research consists of case-control studies, but the number of clinical trials is growing. The dietary recommendations to reduce gastrointestinal cancer risk include lowering total energy, fat, and saturated fat intake; avoidance of grilled and smoked foods; avoidance of alcohol; and increasing intake of fruits, vegetables, and fiber. Studies of esophageal cancer support these dietary approaches, with the exception of dietary fat reduction and increased green tea intake. For gastric cancer, consuming additional fruits and vegetables, including those high in ascorbic acid, may reduce risk, and the capacity for diet to alter Helicobacter pylori infection should be explored. Recent interventional trials do not support a role for high-fiber or low-fat diets in reducing development of colon adenomas, although the evidence does not rule out efficacy at earlier stages of disease. Finally, the evidence for a relationship between pancreatic cancer and diet remains sparse and warrants additional investigation.