Estimating age-specific breast cancer risks: A descriptive tool to identify age interactions
ABSTRACT Clarifying age-specific female breast cancer risks and interactions may provide important etiologic clues.
Using a population-based case-control study in Poland (2000-2003) of 2,386 incident breast cancer cases and 2,502 control subjects aged 25-74 years, we estimated age-specific breast cancer incidence rates according to risk factors.
Breast cancer risks were elevated among women with positive family history (FH), younger age at menarche, older age at first full-term birth, nulliparity, exogenous hormonal usage, and reduced physical activity (PA). Notwithstanding overall risks, we observed statistically significant quantitative (non-crossover) and qualitative (crossover) age interactions for all risk factors except for FH and PA. For example, nulliparity compared to parity reduced breast cancer risk among women ages 25-39 years then rates crossed or reversed, after which nulliparity increased relative risks among women ages 40-74 years.
Though quantitative age interactions could be expected, qualitative interactions were somewhat counterintuitive. If confirmed in other populations, qualitative interactions for a continuous covariate such as age will be difficult to reconcile in a sequential (multistep or monolithic) 'stochastic' breast cancer model. Alternatively, the reversal of relative risks among younger and older women suggests subgroup heterogeneity with different etiologic mechanisms for early-onset and late-onset breast cancer types.
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- "A lot of studies about the association with etiology and risk factors of breast cancer were conducted, particularly physiological and reproductive factors. Various physiological and reproductive factors, including age at menarche, age at menopause, age at first pregnancy and parity have been shown to modify the risk of breast cancer (Oran et al, 2004; Anderson et al, 2007; Iwasaki et al, 2007). Our results in this study also demonstrated that early age at menarche (≤13 years old), later age at menopause (>50 years old) and later age at first pregnancy were associated with an increased risk for breast cancer, and childbirth was associated with a decreased risk for breast cancer. "
ABSTRACT: To evaluate the relationship between physiological, reproductive factors and risk of breast cancer, we conducted a case-control study with 669 cases and 682 population-based controls in Jiangsu Province of China. A structured questionnaire was used to elicit detailed information. All subjects completed an in-person interview. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) as measures of risk for breast cancer. The results have revealed that there was an increasing risk of breast cancer, include early age at menarche(≤ 13 year), late age at menopause(< 50 year) and older age at first pregnancy (≤ 30 year). Breastfeeding was associated significantly with a reduced risk of breast cancer. Women who had history of breastfeeding were at significantly decreased OR (0.44, 95%CI: 0.27-0.73). The protective effects of breastfeeding for breast cancer seemed greater for women who had extended duration of breastfeeding during their lifetime (p for linear trend: 0.0095). These results suggested that physiological and reproductive factors may play important roles in the development of breast cancer among Jiangsu' women of China.Asian Pacific journal of cancer prevention: APJCP 01/2011; 12(3):787-90. · 2.51 Impact Factor
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ABSTRACT: We present a rare case of advanced stage (T4N3M1) breast cancer in a 25-year-old woman with no familial history of the disease and a diagnostic delay of 1 year. Treatment consisted of modified radical mastectomy, radiotherapy, chemotherapy (six cycles of taxotere, adriamycin and cyclophosphamide) and hormonotherapy (tamoxifen). At 2 years of follow-up the patient remains asymptomatic.We review the following topics related to breast cancer: incidence, progression, mortality, recurrences with conservative treatment, radiotherapy, chemotherapy, and quality of life. Other factors are also discussed, such as the use of oral contraceptives, and breast cancer occurring in young women after treatment for Hodgkin's disease.Clínica e Investigación en Ginecología y Obstetricia 05/2010; 37(3). DOI:10.1016/j.gine.2008.10.005