• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3685-3690
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• 2015

Background: Low-dose oral contraceptives (OC) were approved by the Japanese Ministry of Health, Labor and Welfare in 1999, yet despite their contraceptive and non-contraceptive health benefits, only 5% of the target population use them. Fear of increased cancer risk, particularly breast cancer, is one reason for this. Due to low OC uptake and low screening participation, a paucity of data is available on the risk of OC use and breast cancer in Japanese women. The present study investigated OC use and breast cancer risk, as well as menstrual, reproductive and family factors. Materials and Methods: This was a clinic-based case-control study of women aged 20-69yrs who had undergone breast screening between January 2007 and December 2013 in central Tokyo. In all, 28.8% of the participants had experience with OC use. Cases were 155 women with a pathologically confirmed diagnosis of breast cancer. Controls were the remaining 12,333 women. Results: Increased age was a significant risk factor for breast cancer (p<0.001). A lower risk was found in premenopausal women presently taking OC compared to never users (OR 0.45; 95% CI 0.22-0.90) after adjusting for age, parity and breast feeding, and a family history of breast cancer. Conclusions: Increased age rather than OC use had a greater effect on breast cancer risk. This risk may be decreased in premenopausal women with OC use, but further long-term prospective studies are necessary.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2879-2886
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• 2012

In order to thoroughly analyze risk factors of breast cancer (BC) in premenopausal Uruguayan women, a case-control study was carried out at the Pereira Rossell Women's Hospital, Montevideo, where 253 incident BC cases and 497 frequency-matched healthy controls were interviewed on menstrual and reproductive story, were administered a short food frequency questionnaire and undertook a series of body measurements necessary to calculate body composition and somatotype. Odds ratio (OR) coefficients were taken as estimates of relative risk derived from unconditional logistic regression. Among the classical risk factors, only the family history of BC in first degree relatives was significantly associated with risk of premenopausal BC (OR=2.20, 95% CI 1.33-3.62). Interestingly, this risk factor was found to be stronger in women of ages >40 (OR=4.05, 95% CI 2.10-7.81), late menarche (OR= 2.39, 95% CI 1.18-4.85), early age for their first delivery (OR=3.02, 95% CI 1.26-7.22), short time between menarche and first delivery (OR=3.22, 95% CI 1.29-8.07), and with high parity (OR=4.10, 95% CI 1.79-9.36), although heterogeneity was detected only for age and parity. High consumption of red meat was positively associated with the disease risk (OR=2.20, 95% CI 1.35-3.60), in the same way as fried foods (OR=1.79, 95% CI 1.12-2.84). Conversely, a high intake of plant foods displayed a protective effect (OR=0.41, 95% CI 0.26-0.65). Except for hypertension (OR=1.55, 95% CI 1.03-2.35), none of the analyzed components of metabolic syndrome were associated to BC risk. Particular increases of risk for premenopausal BC were found for family history in first degree relatives in certain subsets derived from the menstrual-reproductive history. Preventive strategies could broaden their scope if new studies confirm the present results, in view of the limited prevention measures that premenopausal BC currently has.

• Journal of radiological science and technology
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• v.23 no.1
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• pp.49-54
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• 2000

It is important to identify modifiable risk factors for breast cancer, because the breast cancer is one of the major causs of mortality among women. Some reported that obesity is a risk factor for breast cancer, but the results are not constant. Many risk factors are related to the duration of estrogenic stimulation of the breast. In general, early menarche and late menopause are positive risk factors. Human breast cancer has different characteristics according to the status of menopause(premenopause and postmenopause). In premenopausal women, about 60% of circulating estrogen is from the ovaries in the form of estradiol, and the remaining 40% is estrogen formed primarily in the adipose(fat) tissue via aromatization of androstenedion from the adrenal glands. After menopause this adipose cell production of estrone is the main source of estrogens and the level of estrone is maintained approximately at premenopausal levels. This study was undertaken to determine the role of body size and body mass index by status of menopause in development of breast cancer using retrospective case/control study. From March 1991 to February 1997 at the Wonkwang University Hospital, the breast cancer cases(n=72) and controls(n=86) were selected. By statistical analysis method, regression analysis, paired T-test and multiple logistic regression were done to estimate the influenced factors same as height, weight, BMI, age at menarche and age at menopause. The following results were obtained : 1. In premenopausal women, age at menarche was showed comparatively high correlation coefficients and BMI was described prominently highly in postmenopause. 2. At the results of multiple regression analysis, age at monarch, BMI and weight were showed as significant variables. In this method, critical factor ($R^2$) was 0.054. 3. Paired samples T-test was undertaken to test mean difference between two groups of cases and controls. The result of test performance showed a significant difference. 4. In comparison with women whose weight less than 50 kg, the ORs for the upper 5th group was 1.82(95% confidence interval). The heaviest women had a higher risk(OR=1.14, 95% confidence interval $1.12{\sim}1.31$, p=0.005). Higher body mass index was significantly associated with increased risk of premenopausal breast cancer (OR=1.01, 95% confidence interval $1.08{\sim}l.18$, p=0.05).

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.33-35
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• 2012

To evaluate the relationship between abortions 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. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The results have revealed that induced abortion was related to increased risk of breast caner. Premenopausal women who had ${\geq}3$ times of induced abortion were at increased crude OR (2.41, 95%CI: 1.09-5.42) and adjusted-OR (1.55, 95%CI: 1.15-5.68). Postmenopausal women with a previous induced abortion were at increased crude OR (2.04, 95%CI: 1.48-2.81) and adjusted-OR (1.82, 95%CI: 1.30-2.54), and there was a significant increase trend in OR with number of induced abortions (p for trend: 0.0001). Overall, spontaneous abortion did not significantly alter the risk of breast cancer, but postmenopausal women who had history of spontaneous abortion were at increased OR. These results suggested that relationship between breast cancer and abortions may depend on menopausal status and induced abortion may played an important role in the development of breast cancer in Jiangsu' women of China.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7467-7472
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• 2015

Background: Breast cancer is known to be one of the most prevalent cancers among women in both developing and developed countries. The incidence of breast cancer in Pakistan has increased dramatically within the last few years and is the second country after Israel in Asia to have highest proportional cases of breast cancer. However, there are limited data for breast cancer available in the literature from Pakistan. Objectives: The study was conducted to bring to light the common clinical presentation of breast cancer and to evaluate the frequency of established risk factors in breast carcinoma patients and furthermore to compare the findings between premenopausal and postmenopausal women in Pakistan. Materials and Methods: A 6 months (from July 2012 to Dec 2012) cross sectional survey was conducted in Surgical and Oncology Units of Civil Hospital, Karachi. Data were collected though a well developed questionnaire from 105 female patients diagnosed with carcinoma of breast and analyzed using SPSS version 17. Institutional ethical approval was obtained prior to data collection. Results: Out of 105 patients, 43 were premenopausal and 62 were postmenopausal, 99 being married. Mean age at diagnosis was $47.8{\pm}12.4years$. A painless lump was the most frequent symptom, notived by 77.1%(n=81). Some 55.2% (n=58) patients had a lump in the right breast and 44.8%(n=47) in the left breast. In the majority of cases, the lump was present in upper outer quadrant 41.9% (n=44). Mean period of delay from appearance of symptoms to consulting a doctor was $5.13{\pm}4.8months$, from the shortest 1 month to the longest 36 months. Long delay (> 3 months) was the most frequent figure 41.9%. Considering overall risk factors most frequent were first pregnancy after 20 years of age (41%), physical breast trauma (28.6%), lack of breast feeding(21.9%), and early menarche <11 years (19%), followed by null parity (16.2%), consumption of high fat diet (15.2%), family history of breast cancer or any other cancer in first degree relatives (9.5% and 13.3%, respectively). Some of the less common factors were late menopause >54 years (8.6%), use of oral contraceptive pills (10.5%), use of hormone replacement therapy (4.7%),smoking (4.7%) and radiation (0.96%). Significant differences (p<0.005) were observed between pre and post menopausal women regarding history of physical breast trauma, practice of breast feeding and parity. Conclusions: A painless lump was the most frequent clinical presentation noted. Overall age at first child > 20 years, physical breast trauma, lack of breast feeding, early menarche <11 were the most frequent risk factors. Physical breast trauma, lower parity, a trend for less breast feeding had more significant associations with pre-menopausal than post-menopausal onset. Increase opportunity of disease prevention can be obtained through better understanding of clinical presentation and risk factors important in the etiology of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9579-9586
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• 2014

There is growing scientific evidence linking excess body weight to breast cancer risk. However, there is no common consensus on this relation due partly to methodologies used, populations studied and the cancer subtype. We report here a summary of the present state of knowledge on the role of overweight and obesity in pathogenesis of breast cancer and possible mechanisms through which excess body weight might influence the risk, focusing on the role of oxidative stress in breast cancer etiology. The findings demonstrate duality of excess body weight action in dependence on menopausal status: a statistically significant increased risk in postmenopausal overweight/ obese women and non-significant preventive effect among premenopausal women. Due to several gaps in the literature on this topic, additional studies are needed. Future research should address factors influencing the excess body weight - breast cancer relationship, such as race/ethnicity, tumor subtype, receptor status, the most appropriate measure of adiposity, reproductive characteristics, and lifestyle components.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10543-10555
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• 2015

Breast cancer primary prevention is a high research priority due to the high psychological and economic costs. The disease is a multistep process and several risk factors have been recognized. Over the past three decades numerous studies have investigated the association of lifestyle with breast cancer, showing independent effects of various factors. We report here a summary of the present state of knowledge on the role of lifestyle patterns, such as physical activity, diet, smoking, hormone therapy, and experience of psychological stress in the modulation of breast cancer in women, and discuss commonly accepted biological mechanisms hypothesized as responsible for the associations. The findings indicate that regular physical activity of moderate to vigorous intensity is probably linked with the decreased breast cancer risk among postmenopausal females and suggestive for a decrease of the risk in premenopausal women. In contrast, the consumption of high-fat diet, alcohol intake, and use of combined estrogen and synthetic progestagen hormonal therapy may increase the risk. Epidemiological findings dealing with a role of smoking and experience of psychological stress are conflicting.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.282.2-283
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• 2002

In situ and circulating estrogen is the most important endocrine hormone that promotes the growth of hormone-dependent breast cancer. Consequently. decrease of estrogen on in situ and circulation can inhibit breast cancer. Estrogen is mainly produced by the ovary in premenopausal women and by peripheral tissues such as adipose tissues in postmenopausal women. The cytochrome p450 (CYP19), aromatase. is a key enzyme in the synthesis of estrogen hormones. (omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5193-5198
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• 2013

The glycemic index (GI) and glycemic load (GL) have been considered risk factors for breast cancer, but association studies of breast cancer risk using simple GI and GL might be affected by confounding effects of the overall diet. A total of 357 cases and 357 age-matched controls were enrolled, and dietary intake was assessed using a validated food frequency questionnaire (FFQ) with 103 food items. GI and GL dietary patterns were derived by reduced rank regression (RRR) method. The GI and GL pattern scores were positively associated with breast cancer risk among postmenopausal women [OR (95%CI): 3.31 (1.06-10.39), p for trend=0.031; 9.24 (2.93-29.14), p for trend<0.001, respectively], while the GI pattern showed no statistically significant effects on breast cancer risk, and the GL pattern was only marginally significant, among premenopausal women (p for trend=0.043). The GI and GL pattern scores were positively associated with the risk of breast cancer in subgroups defined by hormone receptor status in postmenopausal women. The GI and GL patterns based on all food items consumed were positively associated with breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4959-4964
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• 2015

Background: To assess the immunohistochemical expression of estrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor-2 (HER2) neu receptor in breast cancer and their associations with various clinicopathological characteristics. Materials and Methods: This is a retrospective analysis of women who presented with primary, unilateral breast cancer in the Department of Medical Oncology at Rajiv Gandhi Cancer Institute and Research Centre, Delhi, India during the period from January 2008 to December 2011. Data were retrieved from the medical records of the hospital including both early and locally advanced cancer cases. ER, PgR and HER2neu expression in these patients was assessed and triple negative patients were identified. Associations of triple negative and non-triple negative groups with clinicopathological characteristics were also evaluated. Results: A total of 1,284 women (mean age 52.1 years, 41.9% premenopausal) were included in the analysis. Hormone receptor positivity (ER and/or PgR) was seen in 63.4% patients, while 23.8% of tumors were triple negative. Only 23.0% were HER2 positive. Around 10.0% of tumors were both ER and HER2 positive. ER and PgR positivity was significantly associated with negative HER2 status (p-value <0.0001). Younger age, premenopausal status, higher tumor grade, lymph node negativity, advanced cancer stage, and type of tumor were strongly associated with triple negativity. Significantly, a smaller proportion of women had ductal carcinoma in situ in the triple negative group compared with the non-triple negative group (35.6% versus 60.8%, p-value<0.01). Conclusions: The present analysis is one of the largest studies from India. The majority of the Indian breast cancer patients seen in our hospital present with ER and PgR positive tumors. The triple negative patients tended to be younger, premenopausal, and were associated with higher tumor grades, negative lymph nodes status and lower frequency of ductal carcinoma in situ.