International journal of cancer. Journal international du cancer
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Estrogens regulate the growth and differentiation of mammary cells and play an important role in the development of breast cancer. High circulating levels of estrogens are associated with increased risk of breast cancer in Caucasian women. Because Asian women have low estrogens in the circulation compared with their Caucasian counterparts, the effect of estrogens on breast cancer risk in populations with low circulating estrogens remains to be elucidated. ⋯ The results showed that breast cancer risk was elevated with increasing levels of estrone and testosterone (p for trend < 0.05) but not with DHEA-S, estradiol, estrone sulfate, progesterone or SHBG. The estimated relative risks between upper and lower tertiles were 2.07 (95% confidence interval [CI] 0.97-4.41) for estrone in postmenopausal women, 2.01 (95% CI 0.96-4.21) for testosterone in premenopausal women, and 2.40 (95% CI 1.11-5.21) for testosterone in postmenopausal women, after adjusting for age at first live birth, waist-to-hip ratio, total calorie intake, a history of fibroadenoma, a family history of breast cancer and SHBG. These results, in general, are consistent with the findings in Caucasian women and indicate that high sex steroid hormones in the circulation, both androgen and estrogen, are associated with increased risk of breast cancer even in populations with relatively low sex hormones.
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Since high energy intake, inactivity, hypertension and diabetes are linked to obesity and an unfavorable hormonal profile, we wanted to test whether energy intake, physical activity, blood pressure and serum glucose are related to the risk of endometrial cancer independent of the body mass index (BMI). A cohort of 24,460 women, aged 20-49 years, attended a Norwegian health screening twice during 1974-1981; they answered questions about diet, physical activity and chronic diseases, and their height, weight, blood pressure and non-fasting serum glucose were measured. By the end of 1996, during 15.7 years of follow-up, 130 cases of endometrial carcinomas were identified. ⋯ Increasing recreational activity tended to be protective. Among obese women with non-sedentary jobs at both screenings, RR declined to 0.18 (95%CI = 0.05-0.62) as the level of sustained occupational activity increased (p(trend) = 0.03). Our results suggest that inactivity and high energy intake are major risk factors for endometrial cancer independent of BMI, and that hypertension and relative hyperglycemia are significant markers of risk, especially among the heaviest women.
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Pain is the most common presenting symptom in patients with bone cancer and bone cancer pain can be both debilitating and difficult to control fully. To begin to understand the mechanisms involved in the generation and maintenance of bone cancer pain, we implanted 3 well-described murine tumor cell lines, 2472 sarcoma, B16 melanoma and C26 colon adenocarcinoma into the femur of immunocompromised C3H-SCID mice. Although each of the tumor cell lines proliferated and completely filled the intramedullary space of the femur within 3 weeks, the location and extent of bone destruction, the type and severity of the pain behaviors and the neurochemical reorganization of the spinal cord was unique to each tumor cell line injected. These data suggest that bone cancer pain is not caused by a single factor such as increased pressure induced by intramedullary tumor growth, but rather that multiple factors are involved in generating and maintaining bone cancer pain.