Showing papers by "Ronald T. Burkman published in 2007"

Timing of Menarche and First Full-Term Birth in Relation to Breast Cancer Risk

Abstract: Ages at menarche and first birth are established risk factors for breast cancer. The interval between these ages may also affect risk, since the breast is more susceptible to carcinogenic insults during this period than during the parous period. However, few investigators have studied this relation. Using logistic regression, the authors evaluated associations between the timing of reproductive events and breast cancer risk among 4,013 cases and 4,069 controls enrolled in a multicenter, population-based US case-control study of White and African-American women (1994-1998). For White, parous premenopausal and postmenopausal women, those who had an interval of > or =16 years between the ages of menarche and first birth had 1.5-fold (95% confidence interval (CI): 1.0, 2.2) and 1.4-fold (95% CI: 1.1, 1.8) increased risks of breast cancer, respectively, in comparison with those who had < or =5 years between these ages. Adjusting for age at first birth altered these risk estimates somewhat, to odds ratios of 1.5 (95% CI: 0.8, 2.9) and 1.0 (95% CI: 0.6, 1.5), respectively. These associations were stronger for lobular and hormone-receptor-positive tumors but were absent among premenopausal African-American women. The authors conclude that the interval between age at menarche and age at first birth is associated with the risk of hormonally sensitive types of breast cancer, particularly among White women.

Risk of breast cancer associated with short-term use of oral contraceptives.

Abstract: To estimate breast cancer risk associated with short-term (<6 months) oral contraceptive use, and explore variation in estimates by use characteristics and medical, menstrual, and reproductive history. We analyzed data from the Women’s Contraceptive and Reproductive Experiences Study. Case subjects were white women and black women, 35–64 years old, diagnosed with invasive breast cancer in July 1994–April 1998. Control subjects identified by random-digit dialing were matched to case subjects by age, race, and study site. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Overall, short-term oral contraceptive use was not associated with breast cancer risk (OR = 1.0; 95% CI = 0.8–1.1). However, significant interaction between short-term use and menopausal status led to an observed increased breast cancer risk in pre-menopausal women (OR = 1.3; 95% CI = 1.0–1.7) and a reduced risk in post-menopausal women (OR = 0.8; 95% CI = 0.6–1.0) associated with short-term use. The association was more pronounced in women with non-contraceptive reasons for use and underlying risk factors for breast cancer. These associations may result from underlying characteristics of users or unmeasured factors influencing duration of use and breast cancer risk.

The transdermal contraceptive patch: an updated review of the literature.

Abstract: The transdermal contraceptive patch which contains ethinyl estradiol and norelgestromin has an efficacy similar to current oral contraceptives (OCs). The major advantages include transdermal application and maintenance of adequate hormonal levels for at least 7 days. Side effects are similar to OC except for breast tenderness in the first 2 months of use and skin irritation at the application site. Although concern has been raised about a possible increased risk of venous thromboembolism, current available data comparing the patch to a norgestimate-containing OC ranges from no increase in risk to a 2.4-fold increase.

Effects of low-dose oral contraceptives on body weight: Results of a randomized study of up to 13 cycles of use

Abstract: Objective To compare the effect of 2 oral contraceptives (OCs) on body weight. Study design A randomized, parallel-group, multicenter study of 1,723 women taking an OC with norgestimate (NGM) 180/215/250 microg/ethinyl estradiol (EE) 25 microg vs. 1,171 women taking on OC with norethindrone acetate 1 mg/EE 20 microg for 6-13 cycles was performed. Body weight changes between baseline and cycle 6 and baseline and cycle 13 were analyzed. Analysis included not only changes in mean body weight but also the distribution of changes that were within 5% of baseline weight, 5-10% of baseline weight and > 10% of baseline weight. Only the 10% change was felt to be clinically significant. Results The distribution of body weight changes did not statistically differ between the 2 OC groups for any parameter measured. The mean weight change after 6 months for the NGM/EE and norethindrone acetate/EE groups was +0.71 kg and +0.57 kg, respectively. At 13 cycles for the NGM/EE and norethindrone acetate/ EE groups, the mean body weight change was +0.93 kg and +0.62 kg, respectively. Only 0.3% of subjects in both OC groups experienced a 10% change in weight. Conclusion Use of OCs does not substantially affect body weight for most women.