Common risk factors of breast and ovarian cancer: recent view

Risk factors for developing both primary breast and primary ovarian cancer: A systematic review

OBJECTIVE

Women with breast cancer have an increased risk of primary ovarian cancer (BR→OV), and women with ovarian cancer have an increased risk of primary breast cancer (OV→BR). This systematic review summarizes risk factors for developing BR→OV and OV→BR.

METHODS

We searched PubMed and Embase until June 2022.

RESULTS

We identified 23 articles meeting our inclusion criteria. Studies observed a lower risk of BR→OV for Black versus White women, alcohol consumption, radiotherapy and hormone therapy, BRCA2 versus BRCA1, and ER/PR positive versus negative breast tumors, and a higher risk with family history of breast/ovarian cancer, triple negative versus luminal breast cancer, and higher grade breast tumors. There was an increased risk of OV→BR with family history of cancer.

CONCLUSIONS

Tumor characteristics, and genetic and familial factors are associated with risk of BR→OV and OV→BR. These results could aid clinicians in decision-making for breast and ovarian cancer patients, including risk-reducing strategies.

Causes of death among women with breast cancer: A follow-up study of 50 481 women with breast cancer in Finland

Our study aims to assess mortality from causes other than breast cancer among women with breast cancer with focus on indications of joint aetiology. Data on female breast cancer patients were obtained from the Finnish Cancer Registry and their underlying causes of death in 54 categories from the Statistics Finland. Standardised mortality ratios (SMR) and their 95% confidence intervals (CIs) were calculated for 50 481 patients diagnosed between 1971 and 2000 and followed until December 2012, stratified by histology, age at diagnosis and time since diagnosis. The expected numbers of deaths were based on respective mortality rates among the Finnish general population. Hazard ratio (HR) was estimated from Poisson regression model to compare risks of cause of death by histology. 41% of 30 841 deaths were due to causes other than breast cancer. Significant excess mortality was observed for stomach cancer (SMR 1.43, 95% CI 1.26-1.62), circulatory system diseases (SMR 1.17, 95% CI 1.14-1.20) and suicide (SMR 1.51, 95% CI 1.28-1.78). In an age-adjusted analysis, significantly higher relative risk of stomach cancer mortality was observed for lobular vs ductal subtype (HR 2.00, 95% CI 1.32-3.02). Significantly increased SMRs were observed for cancers of respiratory organs among premenopausal women, and for other respiratory system diseases, dementia and Alzheimer disease among postmenopausal women. We conclude that female breast cancer patients are at increased risk of death from causes other than the breast cancer diagnosis including circulatory and respiratory system diseases and cancer of stomach, ovary and respiratory systems. The excess mortality because of different causes varies based on menopausal status and histology. There might be shared aetiological factors between the diagnosis of breast cancer and the causes of death among these patients.

A review on methods for diagnosis of breast cancer cells and tissues

Breast cancer has seriously been threatening physical and mental health of women in the world, and its morbidity and mortality also show clearly upward trend in China over time. Through inquiry, we find that survival rate of patients with early‐stage breast cancer is significantly higher than those with middle‐ and late‐stage breast cancer, hence, it is essential to conduct research to quickly diagnose breast cancer. Until now, many methods for diagnosing breast cancer have been developed, mainly based on imaging and molecular biotechnology examination. These methods have great contributions in screening and confirmation of breast cancer. In this review article, we introduce and elaborate the advances of these methods, and then conclude some gold standard diagnostic methods for certain breast cancer patients. We lastly discuss how to choose the most suitable diagnostic methods for breast cancer patients. In general, this article not only summarizes application and development of these diagnostic methods, but also provides the guidance for researchers who work on diagnosis of breast cancer.

Ovarian cancer in a former asbestos textile factory worker: a case report

Background

The International Agency for Research on Cancer (IARC) defined that asbestos is a group 1 substance that causes lung cancer, mesothelioma (pleura and peritoneum), laryngeal cancer, and ovarian cancer in humans. Many studies on lung cancer, and mesothelioma caused by asbestos exposure have been conducted, but there was no case report of ovarian cancer due to asbestos exposure in Korea. We describe a case of ovarian cancer caused by asbestos exposure in a worker who worked at an asbestos textile factory for 3 years and 7 months in the late 1970s.

Case presentation

A 57-year-old woman visited the hospital because she had difficulty urinating. Ovarian cancer was suspected in radiologic examination, and exploratory laparotomy was performed. She was diagnosed with epithelial ovarian cancer. The patient did not undergo postoperative chemotherapy and recovered. She joined the asbestos factory in March 1976 and engaged in asbestos textile twisting and spinning for 1 year, 2 years and 7 months respectively. In addition, she lived near the asbestos factory for more than 20 years. There was no other specificity or family history.

Conclusion

Considering the patient’s occupational and environmental history, it is estimated that she had been exposed to asbestos significantly, so we determined that ovarian cancer in the patient is highly correlated with the occupational exposure of asbestos and environmental exposure is a possible cause as well. Social devices are needed to prevent further exposure to asbestos. It is also necessary to recognize that ovarian cancer can occur in workers who have previously been exposed to asbestos, and the education and social compensation for those workers are needed.

Importance of hereditary and selected environmental risk factors in the etiology of inflammatory breast cancer: a case-comparison study

Background

To assess the importance of heredity in the etiology of inflammatory breast cancer (IBC), we compared IBC patients to several carefully chosen comparison groups with respect to the prevalence of first-degree family history of breast cancer.

Methods

IBC cases (n = 141) were compared to non-inflammatory breast cancer cases (n = 178) ascertained through George Washington University (GWU) with respect to the prevalence of first-degree family history of breast cancer and selected environmental/lifestyle risk factors for breast cancer. Similar comparisons were conducted with subjects from three case–control studies: breast cancer cases (n = 1145) and unaffected controls (n = 1142) from the Cancer Genetic Markers of Susceptibility (CGEMS) study, breast cancer cases (n = 465) and controls (n = 9317) from the Women’s Health Initiative (WHI) study, and ovarian cancer cases (n = 260) and controls (n = 331) from a study by University of Toronto (UT).

Results

The frequency of first-degree breast cancer family history among IBC cases was 17.0 % compared to 24.4 % for GWU breast cancer cases, 23.9 % and 17.9 % for CGEMS breast cancer cases and controls, respectively, 16.9 % and 12.6 % for WHI breast cancer cases and controls, respectively, and 24.2 % and 11.2 % for UT ovarian cancer cases and controls, respectively.

IBC cases had a significantly lower prevalence of parous women than WHI breast cancer cases (OR = 0.46, 95 % CI:0.27–0.81) and controls (OR = 0.31, 95 % CI:0.20–0.49). Oral contraceptive use was significantly higher among IBC cases compared to WHI breast cancer cases (OR = 7.77, 95 % CI:4.82–12.59) and controls (OR = 8.14, 95 % CI:5.28–12.61). IBC cases had a significantly higher frequency of regular alcohol consumption (≥1 drink per day) compared to WHI controls (OR = 1.84, 95 % CI:1.20–2.82) and UT controls (OR = 1.86, 95 % CI:1.07–3.22) and higher (statistically non-significant) prevalence (21.3 %) compared to breast cancer cases from GWU (18.2 %) and WHI (15.2 %).

Conclusions

The prevalence of first-degree breast cancer family history among IBC cases was lower compared to breast and ovarian cancer cases but higher than unaffected individuals. Our multiple-case inflammatory and non-inflammatory breast cancer families may reflect aggregation of common genetic and/or environmental factors predisposing to both types of breast cancer. Our findings that oral contraceptive use and regular alcohol consumption may be associated with IBC warrant further investigations.

Risk of second cancers cancer after a first primary breast cancer: a systematic review and meta-analysis

OBJECTIVE

To examine the scientific evidence and the risk of second primary cancers in women diagnosed with a first primary breast cancer.

METHODS

The literature was searched in Pubmed and Embase and included studies published up to June 2013, using population-based data and IARC/AICR codification rules for multiple primary cancers. A qualitative synthesis was carried out and the methodological quality of the studies evaluated. Standardised incidence ratios (SIRs) on second cancer risk, weighted by the standard error of each study, were pooled using fixed and random effects models. SIRs were also pooled by age at diagnosis (<50 and ≥ 50 years), and time since diagnosis of the first breast cancer (<10 and ≥ 10 years).

RESULTS

15 out of 710 articles fulfilled the inclusion criteria. All of them were retrospective cohort studies either population-based (13 studies) or hospital-based studies (2 studies). The studies varied with respect to number of cases, selection criteria, definition of multiple primary cancers, and the second cancer sites included. SIRs reported in these studies for all cancers combined varied from 1.0 to 1.4. The pooled SIR estimate for second cancer risk was 1.17 (95% CI: 1.10-1.25). By age groups, SIR estimates were 1.51 (95% CI: 1.35-1.70) for women younger than 50 years and 1.11 (95% CI: 1.02-1.21) for those who were older. Women with breast cancer are at risk of second cancers within the first 10 years after the first breast cancer diagnosis (SIR: 1.19; 95% CI: 1.06-1.33), and thereafter (SIR: 1.26; 95% CI: 1.05-1.52).

CONCLUSION

This higher risk of second cancers in women diagnosed with a first primary breast cancer with respect to the general population emphasises the importance of prevention and control policies aimed at reducing incidence of second cancers.

Rapid reduction in breast cancer mortality with inorganic arsenic in drinking water

BACKGROUND

Arsenic trioxide is effective in treating promyelocytic leukemia, and laboratory studies demonstrate that arsenic trioxide causes apoptosis of human breast cancer cells. Region II in northern Chile experienced very high concentrations of inorganic arsenic in drinking water, especially in the main city Antofagasta from 1958 until an arsenic removal plant was installed in 1970.

METHODS

We investigated breast cancer mortality from 1950 to 2010 among women in Region II compared to Region V, which had low arsenic water concentrations. We conducted studies on human breast cancer cell lines and compared arsenic exposure in Antofagasta with concentrations inducing apoptosis in laboratory studies.

FINDINGS

Before 1958, breast cancer mortality rates were similar, but in 1958-1970 the rates in Region II were half those in Region V (rate ratio RR = 0·51, 95% CI 0·40-0·66; p<0·0001). Women under the age of 60 experienced a 70% reduction in breast cancer mortality during 1965-1970 (RR=0·30, 0·17-0·54; p<0·0001). Breast cancer cell culture studies showed apoptosis at arsenic concentrations close to those estimated to have occurred in people in Region II.

INTERPRETATION

We found biologically plausible major reductions in breast cancer mortality during high exposure to inorganic arsenic in drinking water which could not be attributed to bias or confounding. We recommend clinical trial assessment of inorganic arsenic in the treatment of advanced breast cancer.

Computerized database management system for breast cancer patients

Data analysis based on breast cancer risk factors such as age, race, breastfeeding, hormone replacement therapy, family history, and obesity was conducted on breast cancer patients using a new enhanced computerized database management system. My Structural Query Language (MySQL) is selected as the application for database management system to store the patient data collected from hospitals in Malaysia. An automatic calculation tool is embedded in this system to assist the data analysis. The results are plotted automatically and a user-friendly graphical user interface is developed that can control the MySQL database. Case studies show breast cancer incidence rate is highest among Malay women, followed by Chinese and Indian. The peak age for breast cancer incidence is from 50 to 59 years old. Results suggest that the chance of developing breast cancer is increased in older women, and reduced with breastfeeding practice. The weight status might affect the breast cancer risk differently. Additional studies are needed to confirm these findings.

Risk of second primary cancer among women with breast cancer: a population-based study in Granada (Spain)

OBJECTIVE

The higher risk of developing new cancers in breast cancer survivors is a public health concern. Our aim was to examine risk of second primary cancers among women diagnosed with breast cancer.

METHODS

We studied two cohorts of female cancer patients identified in a population-based cancer registry in Granada (Spain): women first diagnosed with a primary breast cancer (n=5897) and those with a primary cancer in another site (n=22,814), followed during 1985-2007 for second cancers and breast cancer occurrence, respectively. We used Standardized Incidence Ratios (SIRs) to estimate second cancer risk by age (<50y, ≥50y), time since diagnosis (≤5y, >5y) and calendar periods (≤1995, >1996). SIR for breast cancer was calculated in the second cohort.

RESULTS

The risk of developing second cancers (n=314) was 39% higher (95% CI=1.23-1.54) among breast cancer patients, and particularly high among women under 50 (SIR=1.96, 95% CI=1.48-2.44). Excess risk for endometrial cancer (SIR=3.04, 95% CI=2.14-3.94) was statistically significant and remained so in women over 50. Younger women were at higher risk of second ovarian cancer (SIR=4.90, 95% CI=1.27-8.53). Increased SIRs were observed during the first five years after breast cancer diagnosis, whereas SIRs decreased thereafter. Breast cancer incidence (n=171) was not higher among women previously diagnosed with other cancer types (SIR=0.86, 95% CI=0.74-1.00).

CONCLUSION

Women diagnosed with breast cancer have a higher incidence of second primary cancers, particularly of endometrial cancer in women over 50 at diagnosis, and ovarian cancer in younger women. These findings may be explained by treatment-related effects or shared risk factors.

Variation in breast cancer risk associated with factors related to pregnancies according to truncating mutation location, in the French National BRCA1 and BRCA2 mutations carrier cohort (GENEPSO)

INTRODUCTION

Mutations in BRCA1 and BRCA2 confer a high risk of breast cancer (BC), but the magnitude of this risk seems to vary according to the study and various factors. Although controversial, there are data to support the hypothesis of allelic risk heterogeneity.

METHODS

We assessed variation in BC risk according to factors related to pregnancies by location of mutation in the homogeneous risk region of BRCA1 and BRCA2 in 990 women in the French study GENEPSO by using a weighted Cox regression model.

RESULTS

Our results confirm the existence of the protective effect of an increasing number of full-term pregnancies (FTPs) toward BC among BRCA1 and BRCA2 mutation carriers (≥3 versus 0 FTPs: hazard ratio (HR) = 0.51, 95% confidence interval (CI) = 0.33 to 0.81). Additionally, the HR shows an association between incomplete pregnancies and a higher BC risk, which reached 2.39 (95% CI = 1.28 to 4.45) among women who had at least three incomplete pregnancies when compared with women with zero incomplete pregnancies. This increased risk appeared to be restricted to incomplete pregnancies occurring before the first FTP (HR = 1.77, 95% CI = 1.19 to 2.63). We defined the TMAP score (defined as the Time of Breast Mitotic Activity during Pregnancies) to take into account simultaneously the opposite effect of full-term and interrupted pregnancies. Compared with women with a TMAP score of less than 0.35, an increasing TMAP score was associated with a statistically significant increase in the risk of BC (P trend = 0.02) which reached 1.97 (95% CI = 1.19 to 3.29) for a TMAP score >0.5 (versus TMAP ≤0.35). All these results appeared to be similar in BRCA1 and BRCA2. Nevertheless, our results suggest a variation in BC risk associated with parity according to the location of the mutation in BRCA1. Indeed, parity seems to be associated with a significantly decreased risk of BC only among women with a mutation in the central region of BRCA1 (low-risk region) (≥1 versus 0 FTP: HR = 0.27, 95% CI = 0.13 to 0.55) (Pinteraction <10-3).

CONCLUSIONS

Our findings show that, taking into account environmental and lifestyle modifiers, mutation position might be important for the clinical management of BRCA1 and BRCA2 mutation carriers and could also be helpful in understanding how BRCA1 and BRCA2 genes are involved in BC.

Occurrence and timing of childhood overweight and mortality: findings from the Third Harvard Growth Study

OBJECTIVE

To assess the mortality experience of participants in the Third Harvard Growth Study (1922-1935) who provided ≥ 8 years of growth data.

STUDY DESIGN

A total of 1877 participants provided an average of 10.5 body mass index measurements between age 6 and 18 years. Based on these measurements, the participants were classified as ever overweight or ever >85th percentile for height in childhood. Age at peak height velocity was used to indicate timing of overweight relative to puberty. Relative risks of all-cause and cause-specific mortality according to measures of childhood growth were estimated using Cox proportional hazards survival analysis.

RESULTS

For women, ever being overweight in childhood increased the risks of all-cause and breast cancer death; the risk of death from ischemic heart disease was increased in men. Men with a first incidence of overweight before puberty were significantly more likely to die from ischemic heart disease; women in the same category were more likely to die from all causes and from breast cancer.

CONCLUSION

We find evidence of long-term effects of having ever been overweight, with some evidence that incidence before puberty influences the pattern of risk.

Induction of ovarian cancer and DNA adducts by Dibenzo[a,l]pyrene in the mouse

Tobacco smoking is an etiological factor of ovarian cacner; however, the mechanisms remain largely undefined. Therefore, as an initial investigation, we examined the carcinogenicity and DNA adducts formation in the ovary of mice treated with DB[a,l]P, a tobacco smoke constituent and environmental pollutant. Ovarian tumors in B6C3F1 mice were induced by direct application of DB[a,l]P (24, 12, 6, and 3 nmol/mouse, three times a week for 38 weeks) into the oral cavity of mice. At 6 nmol, DB[a,l]P induced the highest total ovarian tumor incidence (79%), but the incidence of malignancy was only 15%. However, at the dose of 12 nmol, the total ovarian tumor incidence was 75%, and the incidence of malignancy was 65%. In addition to ovarian tumors, at the dose of 24 nmol, DB[a,l]P induced lesions in sites distal from the ovaries including the skin, mammary, lung, and oral tissues, which were rare at doses lower than 24 nmol. Another bioassay was conducted to detect and quantify DNA adducts induced by DB[a,l]P (24 nmol, three times a week for 5 weeks) in the ovary at 48 h and 1, 2, and 4 weeks after the last administration of DB[a,l]P. DNA was isolated, and the dibenzo[a,l]pyrene-11,12-dihydrodiol-13,14-epoxide (DB[a,l]PDE)-DNA adducts were analyzed by a LC-MS/MS method. DB[a,l]P resulted in the formation of (-)-anti-cis-DB[a,l]PDE-dA and (-)-anti-trans-DB[a,l]PDE-dA adducts, which were 0.8 and 1.6 fmol/10(6) dA, respectively, in ovaries of mice within 48 h, and the level of adducts decreased over a week. Our results indicated that DB[a,l]P can be metabolized to form (-)-anti-DB[a,l]PDE; the latter may, in part, account for DB[a,l]P-induced ovarian cancer. This animal model should assist to better understand the mechanisms, account for the induction of ovarian cancer by tobacco carcinogens, and facilitate the development of chemopreventive agents against ovarian cancer.

Epidemiological characteristics of ovarian cancer in Korea

OBJECTIVE

This study was conducted to examine recent trends in ovarian cancer incidence and mortality and secular trends in demographic factors in Korea.

METHODS

With the data from Korea Central Cancer Registry, International Agency for Research on Cancer, Korean Death Registry, and World Health Organization's Statistical Information System, we calculated age-standardized incidence and mortality rates for ovarian cancer. Also we estimated future incidence of ovarian and cervical cancer using linear regression model. To assess the demographic trend, data from national surveys in Korea or results from published papers were searched.

RESULTS

Ovarian cancer incidence rate was similar to that in women worldwide but lower than those in Western countries, and the trend has been increased steadily. Ovarian cancer-related mortality rates have been increasing in Korea, even though those in western and some Asian countries, such as China, have been decreasing. Age-specific incidence rate and mortality rate showed steep increases with advancing age. The incidence rate of ovarian cancer was estimated to surpass that of uterine cervix cancer in 2015. Korea showed rapid changes in nutritional, reproductive, and anthropometric factors.

CONCLUSION

These recent trends in ovarian cancer incidence and mortality may be partly attributed to gradual westernizing of life styles and to changes in socio-demographic behavior factors. In particular, the increasing trend in ovarian cancer mortality in Korea may be attributed to a real rise in mortality as well as, in part, a decline in misclassification bias related to an increase in the proportion of deaths confirmed by physician diagnosis.

Breast cancer susceptibility alleles and ovarian cancer risk in 2 study populations

Recent genome-wide scans identified several novel breast cancer risk alleles, including variants of the FGFR2, MAP3K1 and LSP1 genes, and a study of associations between these alleles and characteristics of breast cancer patients reported a borderline significant correlation between the number of FGFR2 minor alleles and family history of breast/ovarian cancer. Given these results and similarities in the etiology of breast and ovarian cancer, we examined the association between 7 novel breast cancer susceptibility alleles and epithelial ovarian cancer risk in 2 large study populations. Our analysis included 1,173 cases and 1,201 controls from a New England-based Case-Control study and 210 cases and 603 controls from the prospective Nurses' Health Study. We used logistic regression to estimate the odds ratio (OR) for individuals heterozygous or homozygous for the minor allele at each locus, compared to individuals with the wild-type genotype. We examined the associations separately in each population and, after testing for heterogeneity in the results, pooled the estimates using a random effects model. There was no clear association between these polymorphisms and ovarian cancer risk in either population. The pooled per allele OR for FGFR2 was 1.06 (95% confidence interval (CI)=0.95-1.18) for rs1219648 and 1.04 (95% CI=0.93-1.15) for rs2981582. We had more than 80% power to detect a log-additive OR of 1.16-1.18 per allele at the alpha=0.05 level in the pooled analysis. Our results do not provide strong support for an association between these breast cancer susceptibility alleles and epithelial ovarian cancer risk.

Effect of desire to have a baby on risk acceptance in Turkish infertile women

The aim of this study was to assess whether the desire to escape the psychological condition created by infertility (to have a baby) affected risk-taking behavior, with the possible relationship between ovarian cancer and infertility as the "accepted risk" to overcome infertility. 229 infertile and 204 fertile women who were patients at the Gulhane Military Medical Academy were administered a semistructured questionnaire. Increased ovarian cancer risk was accepted by 67.2% of the infertile women in order to have baby. There was no significant relation between the woman's age, duration of infertility, knowledge of the preventability and curability of ovarian cancer, or acceptable risk. These results indicate the importance to Turkish women of overcoming infertility.

Population attributable fractions for ovarian cancer in Swedish women by morphological type

Using the Swedish Family-Cancer Database, among a total of 1 030 806 women followed from 1993 through 2004, invasive and borderline epithelial ovarian cancer was identified in 3306 and 822 women respectively, with data on family history, reproductive variables, residential region and socioeconomic status. Relative risks and population-attributable fractions (PAFs) were estimated by Poisson regression. The overall PAFs of invasive epithelial ovarian cancer for family history and for reproductive factors were 2.6 and 22.3%, respectively, for serous/seropapillary cystadenocarcinoma (3.0 and 19.1%), endometrioid carcinoma (2.6 and 26.6%), mucinous cystadenocarcinoma (0.5 and 23.9%) and clear-cell carcinoma (2.6 and 73.9%). The corresponding PAFs of borderline tumours due to family history were lower, but higher due to reproductive factors. Family history, low parity and young age at first birth were associated with elevated risks. The risks for women with a family history were among the highest, but these women accounted for the smallest proportion of the cases, giving the lowest PAFs.

Dietary Habits and Risk of Ovarian Cancer Death in a Large-Scale Cohort Study (JACC Study) in Japan

The Japan Collaborative Cohort (JACC) Study was established in 1988-1990 and consisted of 46,465 men and 64,327 women observed until the end of 2003. A self-administered food frequency questionnaire was used as a baseline survey, and associations of dietary habits with the risk of ovarian cancer death were evaluated, taking into consideration age, menstrual and reproductive, anthropometric, and lifestyle factors. During the observation period, 77 women died of ovarian cancer. Hazard ratios for dietary factors were calculated by Cox's proportional hazards model. Being adjusted only for age, high intakes of dried or salted fish and Chinese cabbage were positively associated with the risk of ovarian cancer death, and the risk increased dose-dependently. In contrast, intake of soybean curd (tofu) was inversely associated with the risk. After being adjusted for age and potential confounding factors, the results regarding the intakes of dried or salted fish and Chinese cabbage did not change. However, the significance relating to the intake of soybean curd (tofu) was attenuated. From the results of this cohort study, it was suggested that high intakes of dried or salted fish and Chinese cabbage were potential risk factors of ovarian cancer death. In contrast, however, a high intake of soy bean curd (tofu) might have preventive effects against the risk.

Precursors and preinvasive lesions of the breast: the role of molecular prognostic markers in the diagnostic and therapeutic dilemma

Precursors and preinvasive lesions of the breast include atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), and lobular neoplasia (LN). There is a significant debate regarding the classification, diagnosis, prognosis and management of these lesions. This review article describes the current theories regarding the pathogenesis and molecular evolution of these lesions. It reviews the implication of a variety of molecules in the continuum of breast lesions: estrogen receptors (ER-alpha and ER-beta), c-erb-B2 (Her2/neu), p53, Ki-67, bcl-2, E-cadherin, transforming growth factor-beta (TGF-beta), p27 (Kip1), p16 (INK4a), p21 (Waf1), vascular endothelial growth factor (VEGF). With respect to the aforementioned molecules, this article reviews their pathophysiological importance, and puts the stress on whether they confer additional risk for invasive breast cancer or not. This knowledge has the potential to be of importance in the therapeutic decisions presenting in the common clinical practice.

The association between breastfeeding and breast cancer occurrence among Israeli Jewish women: a case control study

PURPOSE

Breast cancer remains the major malignant disease among Israeli women, with about 4,000 new cases diagnosed annually, and a steadily increasing incidence rates. Early in this century investigators noted that nulliparity and a history of never having breastfed were more common in women with breast cancer than without the disease. Epidemiological evidence on those issues remains controversial. The purpose of this study was to clarify those controversial.

METHODS

A hospital-based case control study was carried out at Nahariya hospital (North of Israel) to assess the risk of breast cancer in relation to breastfeeding history. A total of 256 recent cases of breast cancer (diagnosed between January 1999 and February 2005) and 536 controls were included. Detailed information regarding breastfeeding, menstruation, reproductive factors and confounders was collected. Adjusted odds ratios and 95% confidence intervals were calculated.

RESULTS

Short duration of lifetime breastfeeding, late age at first breastfeeding and experience of insufficient milk were found to increase breast cancer risk. When women who had ever breastfed their infants were compared with females who had not, breastfeeding was found to be protective (OR of 0.39; 95% CI 0.26-0.59).

CONCLUSIONS

These findings may have significant impact on intervention planning aimed towards breast cancer reduction among Israeli Jewish women.

High tea consumption diminishes salivary 17beta-estradiol concentration in Polish women

We hypothesized that among reproductive-age women consuming large quantities of tea, the production of estradiol would be suppressed. It has been shown that catechins and theaflavines, the major constituents of tea, inhibit aromatase, an enzyme which catalyses the conversion of androgens to oestrogens. Our study included Polish women living in urban (n 61) and rural (n 48) areas. Women collected daily saliva samples for one complete menstrual cycle and filled out dietary questionnaires. Saliva samples were analysed by RIA for concentration of 17beta-estradiol (E2). Women with high (above the median) average daily consumption of black tea had reduced levels of salivary E2 in comparison with women who drank less black tea (below the median). This effect was observed within the whole study group, as well as separately within urban (P=0.0006) and rural (P=0.013) groups. High intake of the sum of subclasses of tea catechins and epigallocatechin gallate, assessed using the United States Department of Agriculture database (http://www.nal.usda.gov), was also associated with lower concentrations of E2 within all women (P=0.01 and P=0.0001, respectively) and within the urban group (P=0.0001 and P=0.004, respectively). Similar relationships were observed between the sum of subclasses of theaflavines and thearubigines and E2 levels for the whole group (P=0.002) and for urban women (P=0.02). Women with high consumption of tea had lower levels of E2 concentration throughout the entire menstrual cycle. These results may have implications for reducing hormone-related cancer risk by a relatively easy dietary intervention.

Prevention of ovarian cancer

Ovarian cancer is the leading cause of death from gynaecological malignancy. The incidence is high in the Western world. The incidence of ovarian cancer is reduced by pregnancy, lactation, the oral contraceptive pill and tubal ligation. Lifestyle factors are important in the aetiology of ovarian cancer and current evidence suggests the risk can be reduced by eating a diet rich in fruit and vegetables, taking regular exercise, avoiding smoking, avoiding being overweight and avoiding long-term use of hormonal replacement therapy (HRT). Familial ovarian cancer is responsible for about 10% of ovarian cancer cases. Strategies available to high-risk women include screening (covered elsewhere) and prophylactic salpingo-oophorectomy. The precise role of chemoprevention for high-risk women in the form of the oral contraceptive pill is unclear.

Spontaneous and therapeutic abortions and the risk of breast cancer among BRCA mutation carriers

Introduction

BRCA1 and BRCA2 mutation carriers are at increased risk for developing both breast and ovarian cancer. It has been suggested that carriers of BRCA1/2 mutations may also be at increased risk of having recurrent (three or more) miscarriages. Several reproductive factors have been shown to influence the risk of breast cancer in mutation carriers, but the effects of spontaneous and therapeutic abortions on the risk of hereditary breast cancer risk have not been well studied to date.

Methods

In a matched case-control study, the frequencies of spontaneous abortions were compared among 1,878 BRCA1 mutation carriers, 950 BRCA2 mutation carriers and 657 related non-carrier controls. The rates of spontaneous and therapeutic abortions were compared for carriers with and without breast cancer.

Results

There was no difference in the rate of spontaneous abortions between carriers of BRCA1 or BRCA2 mutations and non-carriers. The number of spontaneous abortions was not associated with breast cancer risk among BRCA1 or BRCA2 mutation carriers. However, BRCA2 carriers who had two or more therapeutic abortions faced a 64% decrease in the risk of breast cancer (odds ratio = 0.36; 95% confidence interval 0.16–0.83; p = 0.02).

Conclusion

Carrying a BRCA1 or BRCA2 mutation is not a risk factor for spontaneous abortions and spontaneous abortions do not appear to influence the risk of breast cancer in carriers of BRCA1 or BRCA2 mutations. However, having two or more therapeutic abortions may be associated with a lowered risk of breast cancer among BRCA2 carriers.

Hormone replacement therapy and the risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers

OBJECTIVE

Hormone replacement therapy (HRT) is commonly prescribed to alleviate the climacteric symptoms of menopause. Recent findings from the Women's Health Initiative has raised questions about the routine use of HRT due to the increased observed incidence of cardiovascular disease and of breast and ovarian cancers in the treatment arm of the trial. In the general population, the association between HRT use and risk of ovarian cancer has not yet been resolved. This association has not been evaluated in BRCA1 or BRCA2 mutation carriers who face very high lifetime risks of both breast and ovarian cancers.

METHODS

We conducted a matched case-control study on 162 matched sets of women who carry a deleterious mutation in either the BRCA1 or BRCA2 gene. Women who had been diagnosed with ovarian cancer were matched to control subjects by mutation, year of birth, and age at menopause. Information on HRT use was derived from a questionnaire routinely administered to women who were found to be carriers of a mutation in either gene. Conditional logistic regression was used to estimate the association between HRT use and the risk of ovarian cancer, stratified by mutation status and type of HRT.

RESULTS

Compared with those who had never used HRT, the odds ratio associated with ever use of HRT was 0.93 (95% CI = 0.56-1.56). There was no significant relationship with increasing duration of HRT use. There was a suggestion that progestin-based HRT regimens might protect against ovarian cancer (odds ratio = 0.57) but this association was not statistically significant (P = 0.20).

CONCLUSION

HRT use does not appear to adversely influence the risk of ovarian cancer in BRCA mutation carriers.