Biomedical subjects

Michael S Simon

Publications and source records attributed to Michael S Simon.

28 records · Page 2Linked to original sources

PubMed2003

Combined effect of oral contraceptive use and hormone replacement therapy on breast cancer risk in postmenopausal women.

OBJECTIVE: We examined breast cancer risk related to lifetime exposure to oral contraceptives (OCs) and hormone replacement therapy (HRT) in postmenopausal women. METHODS: The Women's Contraceptive and Reproductive Experiences (CARE) Study was a population-based case-control study that included 1847 postmenopausal women with incident invasive breast cancer, and 1932 control subjects, identified using random digit dialing. RESULTS: 45% of cases and 49% of controls used both OCs and HRT. OC users were not at increased risk regardless of subsequent HRT exposure. HRT users who had used OCs previously did not have a higher risk of breast cancer than women with no exposure to OCs. We observed a negative interaction (p-value: 0.032) of combined hormone replacement therapy (CHRT) and past OC use. The increase in risk with CHRT was stronger in women who had never used OCs in the past (odds ratio: 1.05; 95% confidence interval: 1.01-1.10 per year of exclusive CHRT use) than in women who had used OCs (odds ratio: 1.00; 95% confidence interval: 0.97-1.03). CONCLUSIONS: We found no indication that adverse effects of exposure to OCs or HRT appeared only in the presence of the other hormone or were exacerbated by exposure to the other hormone.

Adult↗

PubMed2003

Changes in food sources of dietary fat in response to an intensive low-fat dietary intervention: early results from the Women's Health Initiative.

OBJECTIVE: To evaluate changes in food sources of dietary fat made by participants in the Women's Health Initiative Low-Fat Dietary Modification Trial. DESIGN: This study compares sources of dietary fat intake, estimated by a food frequency questionnaire, between intervention and control participants at baseline, 1 year (year 1) and 2 years (year 2) after randomization. The outcome measure was intake of fat in grams per day. Results are given on consumption of fat from six food groups and the intervention effect, defined as mean change in the intervention group minus the change in controls, controlling for baseline fat intake. PARTICIPANTS: 5,004 intervention and 7,426 control postmenopausal women in 40 clinical centers across the United States. RESULTS: At baseline, the major sources of fat were added fats, such as butter, oils, and salad dressings (25%); meats (21%); and desserts (13%). From baseline to year 1, the intervention group reduced fat by 24.3 g/day compared with the control group. Reductions came primarily from added fats (9.1 g/day), meats (4.6 g/day), and desserts (3.9 g/day). White people reduced added fats more than other race/ethnicity groups did, white and Hispanic people were more likely to reduce fat intake from milk and cheese compared with other groups, and Hispanics reduced fat from mixed dishes more than did other race/ethnicity groups (P<.05 for all). APPLICATIONS/CONCLUSIONS: These data indicate that women in the Women's Health Initiative dietary change intervention made substantial changes in food choices. These results can facilitate future low-fat interventions, and also offer clinical applications, by identifying foods that may be refractory to change.

Black or African American↗

PubMed2003

Association of regimens of hormone replacement therapy to prognostic factors among women diagnosed with breast cancer aged 50-64 years.

This study was conducted to assess the histopathological features of breast cancers in women diagnosed with breast cancer at 50-64 years of age who have and have not used hormone replacement therapy (HRT). A case-case analysis of the tumors from women aged 50-64 years who participated in a multicenter population-based case-control study of invasive breast cancer was conducted. In-person interviews collected a detailed history of all episodes of hormone use. Information was collected on selected tumor characteristics from 2346 women with breast cancer. Polytomous logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs), contrasting the histopathological characteristics of the tumors of women who used various regimens of HRT with those of women who have never used HRT. The tumors of cases who used each regimen of HRT were smaller and of earlier stage than those of non-HRT users. Adjustment for screening diminished the magnitude of the effect, and only cases who used estrogen alone (estrogen replacement therapy) had reduced odds of being diagnosed with later-stage disease (regional or distant) than cases who never used HRT (OR, 0.7; 95% CI, 0.6-0.9). Higher proportions of estrogen receptor (ER)- and progesterone receptor (PR)-positive tumors were seen in cases who used any regimen of HRT versus those who did not use HRT. However, after adjustment for age and race, only the tumors of cases who used continuous combined HRT remained more likely to be ER+ and PR+ [OR ER- = 0.6 (95% CI, 0.4-0.9) and OR PR- = 0.5 (95% CI, 0.4-0.7)]. The tumors of women with breast cancer who used HRT have some better prognostic factors than those of women who have not used HRT. However, with the exception of the results noted above, this advantage may be due to the racial and age differences in those who use the various regimens of HRT and the effect of more frequent screening among HRT users, leading to earlier diagnosis.

Age Factors↗

PubMed2002

Relation of regimens of combined hormone replacement therapy to lobular, ductal, and other histologic types of breast carcinoma.

BACKGROUND: The incidence of invasive lobular carcinoma has been increasing among postmenopausal women in some parts of the United States. Part of this may be due to changes in classification over time. However, the use of combined (estrogen and progestin) hormone replacement therapy (CHRT) also has increased during the last decade and may account in part for the increase in invasive lobular breast carcinoma. METHODS: A large, multicenter case-control study of Caucasian and African-American women who were diagnosed at age < 65 years with their first invasive breast tumor from July 1, 1994 through April 30, 1998 was conducted. In-person interviews were conducted with 1749 postmenopausal patients, and their responses were compared with the responses of 1953 postmenopausal control women identified through random-digit dialing who met the study criteria of being postmenopausal at the time of diagnosis. Polytomous logistic regression was used to calculate the odds ratio (OR) as an estimate of the relative risk and to compute the 95% confidence interval (95%CI) associated with the use of various regimens of hormone replacement therapy (HRT) among women diagnosed with ductal breast carcinoma, lobular (or mixed lobular and ductal) breast carcinoma, and a grouping of other histologic types of breast carcinoma. RESULTS: Ever use of unopposed estrogen therapy (ERT) was not associated with an increase in the risk of any histologic type of breast carcinoma. The risk of invasive lobular breast carcinoma and the risk of breast carcinoma of the grouping of other histologies increased among women currently using CHRT (OR, 2.2; 95%CI, 1.4-3.3; and OR, 1.9; 95%CI, 1.0-3.4, respectively). The risk increase was greater for the mixed lobular-ductal type than for the pure lobular type of breast carcinoma, although the difference was not statistically significant. There was some indication that >or= 5 years of continuous CHRT (>or= 25 days per month of progestin) was associated with a higher risk of lobular breast carcinoma (OR, 2.5; 95%CI, 1.4-4.3) compared with sequential CHRT (< 25 days per month of progestin; OR, 1.5; 95%CI, 0.8-2.6). Current use of continuous CHRT was only moderately associated with risk of ductal breast carcinoma. CONCLUSIONS: Postmenopausal women who take CHRT appear to be at an increased risk of lobular breast carcinoma. Data from this study suggest that neither ERT use nor CHRT substantially increase the risk of ductal breast carcinoma among women age < 65 years.

Adult↗

PubMed2002

Oral contraceptives and the risk of breast cancer.

BACKGROUND: It is uncertain whether the use of an oral contraceptive increases the risk of breast cancer later in life, when the incidence of breast cancer is increased. We conducted a population-based, case-control study to determine the risk of breast cancer among former and current users of oral contraceptives. METHODS: We interviewed women who were 35 to 64 years old. A total of 4575 women with breast cancer and 4682 controls were interviewed. Conditional logistic regression was used to calculate odds ratios as estimates of the relative risk (incidence-density ratios) of breast cancer. RESULTS: The relative risk was 1.0 (95 percent confidence interval, 0.8 to 1.3) for women who were currently using oral contraceptives and 0.9 (95 percent confidence interval, 0.8 to 1.0) for those who had previously used them. The relative risk did not increase consistently with longer periods of use or with higher doses of estrogen. The results were similar among white and black women. Use of oral contraceptives by women with a family history of breast cancer was not associated with an increased risk of breast cancer, nor was the initiation of oral-contraceptive use at a young age. CONCLUSIONS: Among women from 35 to 64 years of age, current or former oral-contraceptive use was not associated with a significantly increased risk of breast cancer.

Adult↗

PubMed2002

Hormone replacement therapy regimens and breast cancer risk(1).

Hormone replacement therapy (HRT) has increased in the United States over the past 2 decades in response to reports of long-term health benefits. A relationship between HRT and breast cancer risk has been observed in a number of epidemiological studies. In 2002, the Women's Health Initiative Randomized Controlled Trial reported an association between continuous combined HRT and breast cancer risk. The objective of this study was to examine the association between breast cancer risk and HRT according to regimen and duration and recency of use.A multicenter, population-based, case-control study was conducted in five United States metropolitan areas from 1994 to 1998. Analyzed were data from 3823 postmenopausal white and black women (1870 cases and 1953 controls) aged 35-64 years. Odds ratios (ORs) were calculated as estimates of breast cancer risk using standard, unconditional, multivariable logistic regression analysis. Potential confounders were included in the final model if they altered ORs by 10% or more. Two-sided P values for trend were computed from the likelihood ratio statistic. Continuous combined HRT was associated with increased breast cancer risk among current users of 5 or more years (1.54; 95% confidence interval 1.10, 2.17). Additionally, a statistically significant trend indicating increasing breast cancer risk with longer duration of continuous combined HRT was observed among current users (P =.01). There were no positive associations between breast cancer risk and other HRT regimens. Our data suggest a positive association between continuous combined HRT and breast cancer risk among current, longer term users. Progestin administered in an uninterrupted regimen may be a contributing factor. Risk dissipates once use is discontinued.

Adult↗

PubMed2002

The NICHD Women's Contraceptive and Reproductive Experiences Study: methods and operational results.

PURPOSE: This paper presents methods and operational results of a population-based case-control study examining the effects of oral contraceptive use on breast cancer risk among white and black women aged 35-64 years in five U.S. locations. METHODS: Cases were women newly diagnosed with breast cancer during July 1994 through April 1998. Controls were identified through random digit dialing (RDD) using unclustered sampling with automated elimination of nonworking numbers. Sampling was density-based, with oversampling of black women. In-person interviews were conducted from August 1994 through December 1998. Blood samples were obtained from subsets of cases and controls, and tissue samples were obtained from subsets of cases. A computerized system tracked subjects through study activities. Special attention was devoted to minimizing exposure misclassification, because any exposure-disease associations were expected to be small. RESULTS: An estimated 82% of households were screened successfully through RDD. Interviews were completed for 4575 cases (2953 whites; 1622 blacks) and 4682 controls (3021 whites; 1661 blacks). Interview response rates for cases and controls were 76.5% and 78.6%, respectively, with lower rates for black women and older women. CONCLUSIONS: The methodologic details of this large collaboration may assist researchers conducting similar investigations.

Adult↗

PubMed2002

Methods to increase fruit and vegetable intake with and without a decrease in fat intake: compliance and effects on body weight in the nutrition and breast health study.

Dietary patterns that involve a decrease in fat and an increase in fruit and vegetable (FV) intake have been suggested to decrease cancer risks. In this study, intervention methods to selectively modify dietary fat and/or FV intakes were developed. Compliance to the diets and the effects on body weight are shown, because both of these dietary changes can impact on and be confounded by changes in energy intake. A total of 122 women with a family history of breast cancer were randomized onto one of four diets for 12 mo. Counseling methods were devised to increase amount and variety of FV consumed with or without a decrease in fat intake using modified exchange list diets. Women on the low-fat and combination low-fat/high-FV diet arms decreased their fat intakes to approximately 16% of energy. Women on the high-FV and the combination low-fat/high-FV diet arms increased FV intakes to approximately 11 servings/day. Despite counseling efforts to maintain baseline energy intakes, mean body weight increased significantly by 6 pounds in women in the high-FV diet arm and decreased significantly by 5 pounds in women in the low-fat diet arm. Percent body fat also was increased in the high-FV diet arm and decreased in the low-fat diet arm. Body weight and percent body fat in the combination diet arm did not change significantly. Control of energy intake, therefore, appears to have been achieved only when the addition of FV to the diet was balanced by a decrease in fat intake and both dietary components were enumerated daily. Maintenance of energy intake, therefore, did not appear to be attained intrinsically when individuals were counseled to make changes in the composition of their diets.

Adipose Tissue↗

PubMed2002

Efficacy and economics of hormonal therapies for advanced breast cancer.

Breast cancer is a leading cause of cancer-related mortality among postmenopausal women in the US, and the economic burden of breast cancer care comprises a large percentage of the healthcare budget. Hormonal therapies have a proven place in the management of advanced breast cancer. This type of therapy is more likely to be used in older, compared with younger, women, because tumours in older women are more likely to express estrogen and progesterone receptors. While it is difficult to measure the costs of cancer care because of variation in extent and duration of treatment, treatment-related costs including costs of hormonal agents used for advanced disease account for a relatively small component of the overall costs. Newer hormonal regimens such as the new third generation nonsteroidal (letrozole, anastrozole) and steroidal (exemestane) aromatase inhibitors have shown improved clinical efficacy compared with standard regimens such as megestrol and tamoxifen in the metastatic setting in terms of objective responses or time to tumour progression. In addition the newer agents have improved toxicity profiles. Cost analyses of the newer aromatase inhibitors (anastrozole and letrozole), compared with megestrol, show an optimistic outlook for these agents. Additional work needs to be done looking at a comparison of the efficacy and costs of the aromatase inhibitors relative to the currently recommended hormonal treatments used for women with metastatic breast cancer.

Aged↗

PubMed2002

Do thyroid disorders increase the risk of breast cancer?

The objective of this study was to determine whether thyroid disorders or treatment of such disorders affects the risk of breast cancer. Subjects aged 35-64 years were participants in the National Institute of Child Health and Human Development Women's Contraceptive and Reproductive Experiences Study, a population-based, case-control study of invasive breast cancer that was carried out at five sites in the United States. In-person interviews were completed for 4575 women (cases) with breast cancer (2953 white and 1622 black) and 4682 control women (3021 white and 1661 black). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multiple logistic regression methods. Models included adjustment for age (5-year age groups), race (white or black), and site. A history of any thyroid disorder (OR = 1.1, 95% CI = 0.9-1.2) was not associated with breast cancer risk. Only women with a history of thyroid cancer had an increased risk, but this was restricted to parous women (parous OR = 3.4, 95% CI = 1.5-8.1; nulliparous OR = 0.5, 95% CI = 0.04-5.1). Breast cancer risk was not associated with treatment for thyroid disorders. There was no statistical interaction between thyroid disorders, thyroid treatments, and race, menopausal status, or parity. We found no association between thyroid disorders or their associated treatments and the risk of breast cancer.

Adult↗