Epidemiology of breast cancer

Disparities Associated With Patient Adherence of Post-Breast-Conserving Surgery Surveillance Imaging Protocols

OBJECTIVE

Currently, national and international breast imaging practices utilize variable postsurgical surveillance protocols without uniform recommendations. Due to the innate differences between screening versus diagnostic mammography from scheduling flexibility to out-of-pocket costs, this creates the opportunity for lapses in patient adherence, which has the potential to impact clinical outcomes. The purpose of this study is to evaluate the relationship between sociodemographic factors and postsurgical surveillance imaging protocols on patient adherence rates.

METHODS

This retrospective study reviewed 3 years of surveillance imaging for all patients having breast-conserving surgery at our institution from January 2011 to December 2016. Follow-up adherence was defined as returning for all of the first 3 years of annual follow-up after breast-conserving surgery (institutional surveillance protocol). Associations between adherence to surveillance imaging and patient sociodemographic characteristics were evaluated using univariate and multivariate logistic regression.

RESULTS

The study included 1,082 patients after breast surgery, 715 of whom adhered completely to the first 3 years of annual follow-up (66.1%). Black women were 1.36 times less likely to follow up annually compared with White women (95% confidence interval 1.02-1.80). Similarly, patients with Medicare were 1.84 times less likely to follow up annually compared with patients with private insurance (95% confidence interval 1.34-2.51). Women with benign breast disease after breast-conserving surgery were significantly less likely to adhere to annual surveillance than women with breast cancer.

CONCLUSION

Sociodemographic disparities exist as barriers for annual mammography surveillance in patients after breast-conserving surgery.

Utilization of breast cancer risk prediction models by cancer genetic counselors in clinical practice predominantly in the United States

Risk assessment in cancer genetic counseling is essential in identifying individuals at high risk for developing breast cancer to recommend appropriate screening and management options. Historically, many breast cancer risk prediction models were developed to calculate an individual's risk to develop breast cancer or to carry a pathogenic variant in the BRCA1 or BRCA2 genes. However, how or when genetic counselors use these models in clinical settings is currently unknown. We explored genetic counselors' breast cancer risk model usage patterns including frequency of use, reasons for using or not using models, and change in usage since the adoption of multi-gene panel testing. An online survey was developed and sent to members of the National Society of Genetic Counselors; board-certified genetic counselors whose practice included cancer genetic counseling were eligible to participate in the study. The response rate was estimated at 23% (243/1,058), and respondents were predominantly working in the United States. The results showed that 93% of all respondents use at least one breast cancer risk prediction model in their clinical practice. Among the six risk models selected for the study, the Tyrer-Cuzick (IBIS) model was used most frequently (95%), and the BOADICEA model was used least (40%). Determining increased or decreased surveillance and breast MRI eligibility were the two most common reasons for most model usage, while time consumption and difficulty in navigation were the two most common reasons for not using models. This study provides insight into perceived benefits and limitations of risk models in clinical use in the United States, which may be useful information for software developers, genetic counseling program curriculum developers, and currently practicing cancer genetic counselors.

What is Hidden behind Urban and Semiurban Cancer Incidence and Mortality Differences in Central Italy?

Aims and backround

To analyze differences in cancer incidence and mortality between urban and semiurban municipalities in central Italy.

Methods and Study Design

Population-based survey in the provinces of Florence and Prato in Central Italy involving cancer patients diagnosed between 1985 to 1997 and cancer deaths from 1985 to 1998.

Results

Urban-semiurban incidence ratios were significantly high in both genders for all cancer sites combined (males 1.06, females 1.09), lung (1.11 and 1.37), Kaposi's sarcoma (1.96 and 2.39) and urinary bladder (1.23 and 1.44) and significantly low for stomach cancer (0.76 and 0.84). Among females, urban incidence excesses were present for breast, cervix uteri and skin melanoma and among males for prostate, Hodgkin disease, non-Hodgkin lymphomas and mesotheliomas. Most of the cancer mortality rate ratios corresponded to the incidence rate ratios.

Conclusions

We found that cancer risks and deaths were not homogeneously distributed in the analyzed area, but an urban gradient was present. Part of the differences can probably be attributed to environmental exposures and lifestyle.

Breast Cancer and Ovulation Induction Treatments

BACKGROUND

This study was performed to determine whether the use of ovulation induction drugs in treatment of infertility have a significant effect on the risk of breast cancer.

PATIENTS AND METHODS

This case control study (928 cases, 928 controls), was performed in the gynecology and oncology clinics of Shahid Beheshti University of Medical Sciences between 2011 and 2013. Data were collected via in-person interviews using a questionnaire, which included demographic and gynecologic information. Statistical analysis was performed using SPSS statistics software version 20 (IBM Corp).

RESULTS

The use of ovulation induction drugs was not significantly associated with an increased risk of breast cancer (odds ratio [OR], 1.13; 95% confidence interval [CI], 0.7-1.855) among women with infertility (OR, 1.28; 95% CI, 0.8-1.95).

CONCLUSION

We observed no statistically significant relationship between infertility and ovulation induction drugs with the risk of breast cancer, except for significant increases in the risk of breast cancer among patients who had used fertility drugs for >6 months.

Benign Breast Diseases: Evaluation and Management

Benign breast disease is a spectrum of common disorders. The majority of patients with a clinical breast lesion will have benign process. Management involves symptom control when present, pathologic-based and imaging-based evaluation to distinguish from a malignant process, and counseling for patients that have an increased breast cancer risk due to the benign disorder.

Effects of lifelong exercise training on mammary tumorigenesis induced by MNU in female Sprague-Dawley rats

Breast cancer is the most common malignancy in women worldwide. Several studies have suggested that exercise training may decrease the risk of breast cancer development. This study aimed to evaluate the effects of long-term exercise training on mammary tumorigenesis in an animal model of mammary cancer. Fifty female Sprague-Dawley rats were randomly divided into four groups: MNU sedentary, MNU exercised, control sedentary and control exercised. Animals from MNU groups received an intraperitoneal administration of N-methyl-N-nitrosourea (MNU). Animals were exercised on a treadmill during 35 weeks. When animals were killed, blood samples were collected to determine the hematocrit and to perform the biochemical analysis. Mammary tumors were collected and histologically evaluated; the expression of ERs α and β was evaluated in tumor sections by immunohistochemistry. All survived animals from both MNU groups developed mammary tumors. The number of mammary tumors (p > 0.05) and lesions (p = 0.056) was lower in MNU exercised than in MNU sedentary animals. MNU exercised animals showed lower number of malignant lesions than MNU sedentary animals (p = 0.020). C-reactive protein serum concentration was lower in exercised animals; however, the levels of 17-β estradiol were higher in exercised animals. Tumors from exercised animals exhibited higher expression of ER α than tumors from sedentary animals (p < 0.05). This study analyzes the impact of the longest exercise training protocol on mammary tumorigenesis ever performed. We concluded that the lifelong endurance training has beneficial effects on mammary tumorigenesis in female rats (reduced the inflammation, the number of mammary tumors and lesions, and histological grade of malignancy). Additionally, the mammary tumors from MNU exercised group exhibited higher immunoexpression of ER α that is an indicator of well-differentiated tumors and better response to hormone therapy.

Recent perspectives on the anticancer properties of aqueous extracts of Nigerian Vernonia amygdalina

Innovative developments are necessary for treating and defeating cancer, an oftentimes deadly group of diseases characterized by the uncontrolled growth and spread of abnormal cells. Breast cancer (BC) is the second leading cause of cancer-related deaths of women in the USA, and prostate cancer (PC) is the second leading cause of cancer-related deaths of American men. Although some efficacious BC drugs are pharmaceutically marketed, they affect the quality of life for some patients because they are toxic in that their usages have been accompanied by side effects such as stroke, thrombosis, slow heart rate, seizure, increased blood pressure, nausea, emesis, and more. Therefore, there is an urgent need for the discovery of molecular markers for early detection of this disease and discovery of targets for the development of novel, less toxic therapeutics. A botanical plant Vernonia amygdalina has been widely used in Nigerian and other Central and West African cultures for centuries as an herbal medicine. Mounting evidence suggests that treatment with low concentrations of aqueous leaf extracts of the edible Nigerian V. amygdalina plant (Niger-VA) arrests the proliferative activities and induces apoptosis in estrogen receptor-positive, estrogen receptor-negative, and triple-negative human breast cancerous cells and in androgen-independent human PC-3. Also, in athymic mice, Niger-VA potentiates increased efficacies and optimizes treatment outcomes when given as a cotreatment with conventional chemotherapy drugs. Evidence of its noticeable cytostatic activities ranging from changes in DNA synthesis to growth inhibition, mechanisms of inducing apoptosis in different cancer cell lines, and in vivo antitumorigenic activities and chemopreventive efficacy reinforce the idea that Niger-VA deserves increased attention for further development as a phytoceutical, anticancer drug entity. Hence, the present review article highlights impactful published literature on the anticancer effects of Niger-VA in multiple cancerous cell lines and in a nude mouse model, supporting its potential usefulness as a natural product, chemotherapeutic medicine for treatment of both BC and PC.

Histopathological Features of Non-Neoplastic Breast Parenchyma Do Not Predict BRCA Mutation Status of Patients with Invasive Breast Cancer

BACKGROUND

Several studies have evaluated histologic features of non-neoplastic breast parenchyma in patients with BRCA1/2 mutations, but the results are conflicting. The limited data suggest a much higher prevalence of high-risk precursor lesions in BRCA carriers. Therefore, we designed this study to compare the clinicopathological characteristics of peritumoral benign breast tissue in patients with and without deleterious BRCA mutations.

METHODS

Women with breast cancer (BC) who were referred for genetic counseling and underwent BRCA genetic testing in 2010 and 2011 were included in the study.

RESULTS

Of the six benign histological features analyzed in this study, only stromal fibrosis grade 2/3 was found to be statistically different, with more BRCA noncarriers having stromal fibrosis grade 2/3 than BRCA1/2 carriers (P = 0.04).

CONCLUSION

There is no significant association between mutation risk and the presence of benign histologic features of peritumoral breast parenchyma.

Trends in menarcheal age between 1955 and 2009 in the Netherlands

AIM

To assess and compare the secular trend in age at menarche in Dutch girls (1955-2009) and girls from Turkish and Moroccan descent living in the Netherlands (1997-2009).

METHODS

Data on growth and maturation were collected in 20,867 children of Dutch, Turkish and Moroccan descent in 2009 by trained health care professionals. Girls, 9 years and older, of Dutch (n = 2138), Turkish (n = 282), and Moroccan (n = 295) descent were asked whether they had experienced their first period. We compared median menarcheal age in 2009 with data from the previous Dutch Nationwide Growth Studies in 1955, 1965, 1980 and 1997. Age specific body mass index (BMI) z-scores were calculated to assess differences in BMI between pre- and postmenarcheal girls in different age groups.

RESULTS

Median age at menarche in Dutch girls, decreased significantly from 13.66 years in 1955 to 13.15 years in 1997 and 13.05 years in 2009. Compared to Dutch girls there is a larger decrease in median age of menarche in girls of Turkish and Moroccan descent between 1997 and 2009. In Turkish girls age at menarche decreased from 12.80 to 12.50 years and in Moroccan girls from 12.90 to 12.60 years. Thirty-three percent of Turkish girls younger than 12 years start menstruating in primary school. BMI-SDS is significantly higher in postmenarcheal girls than in premenarcheal girls irrespective of age.

CONCLUSION

There is a continuing secular trend in earlier age at menarche in Dutch girls. An even faster decrease in age at menarche is observed in girls of Turkish and Moroccan descent in the Netherlands.

Update on age at menarche in Italy: toward the leveling off of the secular trend

PURPOSE

To update the information on age at menarche in the Italian population and to verify the influence of genetic, nutritional, and socioeconomic factors on menarcheal age. Recent studies suggest that the magnitude of the secular trend toward an earlier age at menarche is slackening in industrialized countries.

METHODS

This multicenter study was conducted on a large, population-based sample of Italian high school girls (n = 3,783), using a self-administered questionnaire. The questionnaire was used to gather information on the girls, including demography, anthropometry, menarcheal date, regularity of menses, behavioral habits, and physical activity. The questionnaire was also used to gather information on parents, including demography and mothers' and sisters' menarcheal ages. The median age at menarche and its 95% confidence interval were estimated by means of Kaplan-Meier survival analysis. To identify the independent predictive factors of age at menarche, multivariate mixed-effects models were applied.

RESULTS

The median age at menarche of the subjects was 12.4 years (95% confidence interval: 12.34-12.46). The girls had their first menses approximately one-quarter of a year (median-0.13) earlier than did their mothers (p < .0001). Among all variables, parents' birth area, body mass index, family size, and the mother's menarcheal age were significantly and independently associated with age at menarche.

CONCLUSIONS

This study confirmed the reduction in the trend toward earlier menarche in Italy. The results also confirmed that genetic and nutritional factors are strong markers for early menarche. Currently, socioeconomic factors do not seem to play as significant a role as in the past.

Loss of caveolin-3 induces a lactogenic microenvironment that is protective against mammary tumor formation

Here, we show that functional loss of a single gene is sufficient to confer constitutive milk protein production and protection against mammary tumor formation. Caveolin-3 (Cav-3), a muscle-specific caveolin-related gene, is highly expressed in muscle cells. We demonstrate that Cav-3 is also expressed in myoepithelial cells within the mammary gland. To determine whether genetic ablation of Cav-3 expression affects adult mammary gland development, we studied the phenotype(s) of Cav-3(-/-)-null mice. Interestingly, Cav-3(-/-) virgin mammary glands developed lobulo-alveolar hyperplasia, akin to the changes normally observed during pregnancy and lactation. Genome-wide expression profiling revealed up-regulation of gene transcripts associated with pregnancy/lactation, mammary stem cells, and human breast cancers, consistent with a constitutive lactogenic phenotype. Expression levels of three key transcriptional regulators of lactation, namely Elf5, Stat5a, and c-Myc, were also significantly elevated. Experiments with pregnant mice directly showed that Cav-3(-/-) mice underwent precocious lactation. Finally, using orthotopic tumor cell implantation, we demonstrated that virgin Cav-3(-/-) mice were dramatically protected against mammary tumor formation. Thus, Cav-3(-/-) mice are a novel preclinical model to study the protective effects of a lactogenic microenvironment on mammary tumor onset and progression. Our current studies have broad implications for using the lactogenic microenvironment as a paradigm to discover new therapies for the prevention and/or treatment of human breast cancers.

Socioeconomic status in relation to early menarche among black and white girls

OBJECTIVE

Early menarche is a risk factor for breast cancer. We investigated the variation in age at menarche by socioeconomic status (SES) and race.

METHODS

A cohort study was conducted on 1,091 black and 986 white girls from the three sites in the United States as part of the NHLBI Growth and Health Study (NGHS), who were aged 9-10 years at baseline and followed through adolescence over a 10-year period with annual exams. Using logistic regression models, we evaluated the nature and strength of associations between two socioeconomic indicators (household income and parental education) and early menarche (<12 years old) unadjusted and adjusted for anthropometry and maternal age at menarche.

RESULTS

Proportionately, more black girls were menarcheal before 12 years of age compared to their white counterparts (46%, n = 468 vs. 26%, n = 240, respectively, p < 0.0001). Parental education was not a significant predictor of early menarche. The graded association between household income and age at menarche was strong and significant among black girls but less clear among white girls. Compared with those in the lowest quartile of household income, white girls in the highest quartile were at a significantly lower risk of early menarche [adjusted odds ratio (OR) = 0.37, 95% confidence intervals (CIs) 0.18-0.80]. The inverse was true for black girls: those in the highest quartile of household income were at an increased risk of early menarche (adjusted OR = 2.15, 95% CI 1.27-3.63)

CONCLUSION

The SES factor selected (household income versus parental education) affected the findings regarding racial differences in the timing of menarche. It will be important for future studies to elucidate the link between household income and age at menarche in developed countries.

Practice of antenatal clinical breast examination as a method of early detection of breast cancer by health care providers in a low resource setting

BACKGROUND

Clinical breast examination (CBE) provides an important screening tool for the earlier detection of breast cancer among women in populations such as ours where mammography is not widely available as a screening tool. There is a paucity of data on the level of practice of antenatal CBE by health-care providers at Aba, South Eastern Nigeria.

OBJECTIVE

To determine the level of practice of antenatal CBE by health-care providers as a method of early detection of breast cancer.

METHOD

A descriptive study involving 100 consecutive and consenting patients at the antenatal clinic of Abia State University Teaching Hospital, Aba, South Eastern Nigeria over the period 1 June-15 June 2007 was carried out. Using a structured questionnaire, the respondents' socio-demographic data were obtained, as well as their knowledge of breast cancer and of what breast cancer examination screens for, and self-reported data on their having ever received CBE during the current antenatal period.

RESULTS

The knowledge of breast cancer was poor. Although 99% of the women had heard of breast cancer, only 34% of them knew what breast examination screened for, whilst only 1 and 2% had received CBE by doctors and nurses, respectively, during the current antenatal period. No breast abnormalities or suspicious nodes were detected during the antenatal CBEs.

CONCLUSION

The level of practice of routine antenatal CBE by health-care providers is very low in our setting. Health-care providers should perform a thorough breast examination at the first prenatal visit and maintain a high index of suspicion for breast cancer throughout pregnancy.

Risk of Breast Cancer After Exposure to Fertility Drugs: Results from a Large Danish Cohort Study

BACKGROUND

Few epidemiologic studies have examined the association between fertility drugs and breast cancer risk, and results have been contradicting. Using data from the largest cohort of infertile women to date, the aim of this study was to examine the effects of fertility drugs on breast cancer risk overall and according to histologic subtypes.

METHOD

A cohort of 54,362 women with infertility problems referred to all Danish fertility clinics between 1963 and 1998 was established. A detailed data collection, including information of type and amount of treatment, was conducted. We used case-cohort techniques to calculate rate ratios (RR) of breast cancer associated with use of five groups of fertility drugs, after adjustment for parity status.

RESULTS

Three hundred thirty-one invasive breast cancers were identified in the cohort during follow-up through 1998. Analyses within cohort showed no overall increased breast cancer risk after use of gonadotrophins, clomiphene, human chorionic gonadotrophin, or gonadotrophin-releasing hormone, whereas use of progesterone increased breast cancer risk (RR, 3.36; 95% confidence interval, 1.3-8.6). For all groups of fertility drugs, no relationships with number of cycles of use or years since first use of fertility drug were found. However, gonadotrophins may have a stronger effect on breast cancer risk among nulliparous women (RR, 1.69; 95% confidence interval, 1.03-2.77). Similar risk patterns were present for ductal, lobular, and tumors of other histologies, indicating identical etiologies.

CONCLUSION

The results showed no strong association between breast cancer risk and use of fertility drugs. Follow-up is, however, needed to assess long-term breast cancer risk after use of progesterone and among nulliparous women exposed to gonadotrophins.

Benign breast diseases: classification, diagnosis, and management

Benign breast diseases constitute a heterogeneous group of lesions including developmental abnormalities, inflammatory lesions, epithelial and stromal proliferations, and neoplasms. In this review, common benign lesions are summarized and their relationship to the development of subsequent breast cancer is emphasized.

Ashkenazi Jews and breast cancer: the consequences of linking ethnic identity to genetic disease

We explored the advantages and disadvantages of using ethnic categories in genetic research. With the discovery that certain breast cancer gene mutations appeared to be more prevalent in Ashkenazi Jews, breast cancer researchers moved their focus from high-risk families to ethnicity. The concept of Ashkenazi Jews as genetically unique, a legacy of Tay-Sachs disease research and a particular reading of history, shaped this new approach even as methodological imprecision and new genetic and historical research challenged it. Our findings cast doubt on the accuracy and desirability of linking ethnic groups to genetic disease. Such linkages exaggerate genetic differences among ethnic groups and lead to unequal access to testing and therapy.

Breast cancer risk factors according to joint estrogen receptor and progesterone receptor status

BACKGROUND

We investigated risk factor patterns for subtypes of breast cancer characterized by joint estrogen receptor (ER) and progesterone receptor (PR) status in a hospital-based case-control study.

METHODS

ER and PR tumor status were determined immunohisotchemically. Risk factors of interest were entered into a multiple polychotomous logistic regression model simultaneously; odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Using this model, cases in the four tumor subtypes (ER+PR+, ER-PR-, ER+PR-, ER-PR+) were compared simultaneously to controls. A Wald test for heterogeneity across the four subtypes was conducted, as well as a case-case comparison between the two most biologically disparate subtypes, ER+PR+ and ER-PR-.

RESULTS

The receptor status distribution was as follows: 33% ER+PR+, 34% ER-PR-, 20% ER+PR-, and 13% ER-PR+. Among 317 cases and 401 controls, we found significant heterogeneity across the four tumor subtypes for older age at first full-term pregnancy (p=0.04) and post-menopausal status (p=0.04). For older age at first full-term pregnancy, an elevated risk was found for the ER+PR- subtype (OR=2.5; 95% CI: 1.2-5.1). For post-menopausal status, elevated risks were found for both the ER+PR+ (OR=2.4; 95% CI: 1.1-4.9) and ER+PR- (OR=7.2; 95% CI: 2.4-21.7) subtypes. From the case-case comparisons, we found that cases, who had consumed alcohol for more than 1 year were 3.4 times more likely to have ER+PR+ tumors than ER-PR- tumors (95% CI: 1.4-8.4).

CONCLUSIONS

Certain breast cancer risk factors may vary by ER and PR status, and joint ER/PR status should be taken into account in future studies of risk factor estimates.

Growth inhibition and cell cycle arrest effects of epigallocatechin gallate in the NBT-II bladder tumour cell line

OBJECTIVES

To examine the growth inhibition and cell cycle arrest effects of epigallocatechin gallate (EGCG), a major constituent of green tea polyphenols, on the NBT-II bladder tumour cell line.

MATERIALS AND METHODS

Growth inhibition and cell cycle arrest effects of EGCG were evaluated by the tetrazolium assay, flow cytometry and apoptotic DNA ladder tests. The cell cycle-related oncogene and protein expressions in NBT-II bladder tumour cells, when incubated with EGCG, were detected with reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis.

RESULTS

EGCG inhibited growth of the NBT-II bladder tumour cells in a dose- and time-dependent manner. Flow cytometry showed a G0/G1 arrest in cells when cultured with EGCG at doses of 10, 20 or 40 micro mol/L for 48 or 72 h. The apoptotic DNA ladder test showed that EGCG at 10 micro mol/L induced early apoptosis after 48 h of incubation. A down-regulation of cyclin D1 was detected by RT-PCR when the cells were incubated with EGCG (20 micro mol/L for 48 h. EGCG also down-regulated protein expression of cyclin D1, cyclin-dependent kinase 4/6 and phosphorylated retinoblastoma protein, in both a time- and dose-dependent manner, when detected by Western blot.

CONCLUSION

EGCG had growth inhibition and cell-cycle arrest effects in NBT-II bladder tumour cells by down-regulating the cyclin D1, cyclin-dependent kinase 4/6 and retinoblastoma protein machinery for regulating cell-cycle progression.

Risk models used to counsel women for breast and ovarian cancer: a guide for clinicians

Advances in the identification and treatment of breast and ovarian cancer have lead to a need for reliable estimates of susceptibility risk associated with these two cancers. These estimates may be used in clinical settings to identify individuals at increased risk of developing disease or of being a carrier of a disease susceptibility allele. Accurate assessment of these probabilities is important given the potential implications for medical decision-making including the identification of patients who might benefit from preventive measures, genetic counseling or from entry into clinical trials. A wide range of empirical and statistical models has been proposed, particularly for breast cancer risk prediction, including those that utilize logistic regression or Bayesian modeling. The specific data used to create the various risk models also varies and may include molecular, epidemiologic, or clinical information. This overview presents definitions of risk used in clinical oncology as well as several of the more frequently used methods of risk estimation for breast and ovarian cancer. In addition, the means by which different methods are able to provide a measure of error or uncertainty associated with a given risk estimate will be discussed.

Clinicopathological study of Japanese male breast carcinoma

BACKGROUND

Male breast cancer accounts for less than 1% of all cancers in men. Compared to breast cancer in women, the natural history and prognosis of breast cancer in men is controversial.

METHODS

A retrospective review was performed for 15 cases of male breast carcinoma, who were surgically treated in the Department of Surgery, Oita Prefectual Hospital, Oita, Japan, between 1980 and 2001.

RESULTS

Two men were classified as presenting with stage 0 disease by the TNM classification, two as stage I, four as stage II, and six as stage III. Two received chemotherapy, four received hormone therapy, and seven received combined therapy. ER was positive in 7 of 10 patients, and PgR in 8 of 10. Only one patient died of tumor recurrence, and this was 15.9 years after surgery. A trend was observed toward negative nodal involvement, earlier TNM stage at diagnosis, and an increase in the use of modified radical mastectomy.

CONCLUSIONS

A favorable prognosis was recognized in male breast carcinoma, regardless of late stage, and hormonal therapy should be used for patients suffering from this disease.

Human murine mammary tumour virus-like agents are genetically distinct from endogenous retroviruses and are not detectable in breast cancer cell lines or biopsies

It has been reported that a human murine mammary tumour virus (MMTV)-like virus (HMLV), which may be an endogenous human retrovirus (HERV), occurs in the human breast cancer cell lines T47D and MCF-7 and, in 38% of human breast cancer biopsies. As the aetiology of most breast cancers remains unknown, it is important to verify these observations in differing breast cancer populations worldwide. Thus, we sought to determine the genetic relationships between HMLVs, MMTVs, and HERVs, and to investigate the association between HMLVs and breast cancer biopsies from South London, UK. Phylogenetic analyses of the env/pol region indicated that HMLVs are indistinct from MMTVs, and that MMTVS/HMLVs exhibit only low sequence homologies with HERVs. A search of the human genome confirmed that HMLVs are not endogenous. Using MMTV polymerase chain reaction (PCR) primers described previously, we amplified DNA from all cell lines except MCF-7 and from 7 of 44 (16%) breast cancer biopsies. A restriction fragment length polymorphism assay was designed to distinguish between HMLVs and MMTVs, and upon analyses, PCR amplicons appeared to be HMLVs. To confirm these findings, amplicons from the T47D cell line and from four randomly selected breast cancer patients were sequenced. Of 106 DNA sequences obtained, 103 were homologous with a short arm of human chromosome (Chr) 3 (3p13), two with Chr 4, and one with Chr 8. None of the sequences exhibited significant nucleotide homology with MMTVs, HMLVs, or with HERVs (all <50%). Thus, we conclude that (i) HMLVs are integral members of the MMTV family; (ii) MMTVs/HMLVs are genetically distinct from HERVs; (iii) MMTV/HMLV DNA is not present in human breast cancer cell lines or clinical biopsies in our locality.

Management of the high-risk patient

Comprehensive breast cancer risk management is a practical tool that can now be regarded as a necessary clinical component of women's health. Risk assessment is the starting point for counseling women about risk, and it facilitates rational decision-making about prophylactic surgery, initiation of screening at an early age, and initiating preventive interventions. The availability of risk assessment models permit rapid risk calculation during routine clinical encounters, and risk profiles can be easily updated at subsequent clinical visits. Clinicians can now incorporate risk assessment and management into their routine screening and health maintenance appointments. Additional prospective clinical trials should be conducted to define the optimal use of existing management strategies, develop refined risk assessment instruments that incorporate additional risk-factor information, and evaluate populations for whom validated risk-assessment approaches do not yet exist.

A novel approach of targeted ablation of mammary carcinoma cells through luteinizing hormone receptors using Hecate-CGbeta conjugate

Recent studies have shown that human and animal mammary gland carcinoma cell line express luteinizing hormone receptors (LHRs). We have examined the cytotoxic effect of Hecate-CGbeta conjugate, that is, fusion of a lytic peptide (Hecate) and a 15-amino acid fragment of the CGbeta-chain in vitro. To test the hypothesis that the Hecate-CGbeta conjugate selectively abolishes cells possessing LHR, estrogen dependent and independent human breast cancer cell lines (MCF-7; MDA-MB-231) and a mouse Leydig tumor cell line (BLT-1) were treated in vitro with Hecate-CGbeta conjugate and Hecate alone. Cytotoxic effects of the Hecate-CGbeta conjugate and the Hecate alone was measured by lactate dehydrogenase (LDH) release immediately after treatment. We observed that the Hecate-CGbeta conjugate selectively, in dose-dependent manner destroys cells possessing LHR in lower concentrations of preparate comparing to the Hecate alone and that the cytotoxic effect is strongly correlated with the number of LHR. Using Western blot analysis we characterized the LHR on membranes of MDA-MB-231, MCF-7 and BLT-1 tumor cell lines. In addition, we showed the evaluation of inhibition potential of the Hecate-CGbeta conjugate to LHR. At a concentration of 33 microM the conjugate inhibited (50%; IC50) the binding of CG to LHR. We suggest further development of this novel approach for the treatment of breast cancer by the Hecate-CGbeta for in vivo trials.

Rating the risk factors for breast cancer

OBJECTIVE

To update and summarize evidence of risk factors for breast cancer.

SUMMARY BACKGROUND DATA

Women who are at high risk for breast cancer have a variety of options available to them, including watchful waiting, prophylactic surgery, and chemoprevention. It is increasingly important to accurately assess a patient's risk profile to ensure that the cost/benefit ratio of the selected treatment is favorable.

METHODS

Estimates of relative risk for documented risk factors were obtained from seminal papers identified in previous reviews. These estimates were updated where appropriate with data from more recent reports using large sample sizes or presenting meta-analyses of previous studies. These reports were identified from a review of the Medline database from 1992 to 2002.

RESULTS

Risk factors that have received a great deal of publicity (hormone use, alcohol consumption, obesity, nulliparity) present a relatively modest relative risk for breast cancer (<2). Factors associated with a prior history of neoplastic disease or atypical hyperplasia and factors associated with a genetic predisposition significantly affect the risk of breast cancer, with relative risks ranging from 3 (for some cases of positive family history) to 200 (for premenopausal women positive for a BRCA mutation).

CONCLUSIONS

More precise tools, based on techniques of molecular biology such as microarray analysis, will be needed to assess individual risk for breast cancer.

Breast density and breast cancer risk factors in a high-risk population

This study investigates relationships between familial and hormonal risk factors and breast density in women at high risk of developing breast cancer. The subjects are a subset of 102 women from the international breast cancer intervention study (IBIS), for whom a series of repeated measurements of breast density were available. Details of familial and hormonal risk factors for breast cancer were collected at entry and multivariate ordered logistic regression used to identify risk factors for increased breast density. Lower body mass index and nulliparity were associated with high breast density, whereas smoking was associated with lower breast density. It is not yet known whether a reduction in breast density will lead to a corresponding reduction in breast cancer risk, so we propose that changes in breast density be investigated as a potential early indicator of efficacy in chemoprevention trials for breast cancer.

Familial risk factors for breast cancer among Arab women in Israel

The incidence of breast cancer in Arab women is low compared with western populations in other countries. Very few studies on risk factors for breast cancer in Arab women have been reported. The aim of the present study was to evaluate familial risk factors for breast cancer among Arab women in Israel. A case-control study was carried out on 72 Arab women diagnosed with breast cancer and 140 healthy controls. Cases were identified through oncology wards and controls were sampled from community and hospital out-patient clinics. All participants were interviewed and information obtained on family history of breast cancer and other cancers, and other potential risk factors. Eight women with breast cancer and five women without breast cancer had a first-degree relative with breast cancer. The odds ratio for breast cancer for a woman with a first-degree relative with breast cancer was 3.4 (95% confidence interval (CI) 1.06-10.7, P = 0.04). The odds ratio for Muslim women with a first-degree relative with breast cancer was higher than that for Christian women (6.07 and 1.53, respectively). Family history of breast cancer was a risk factor for breast cancer in Arab women. The estimated relative risk associated with an affected first-degree relative was generally higher than that reported from other populations.

Factors associated with interval adherence to mammography screening in a population-based sample of New Hampshire women

BACKGROUND

Interval adherence to mammography screening continues to be lower than experts advise. The authors evaluated, using a population-based mammography registry, factors associated with adherence to recommended mammography screening intervals.

METHODS

The authors identified and recruited 625 women aged 50 years and older who did and did not adhere to interval mammography screening. Demographic and risk characteristics were ascertained from the registry and were supplemented with responses on a mailed survey to assess knowledge, perceived risk, anxiety regarding breast carcinoma and its detection, and women's experiences with mammography.

RESULTS

The authors found no differences in risk factors or psychologic profiles between adhering and nonadhering women. Women who did not adhere had a statistically higher body mass index than women who did adhere (27.6 versus 26.1, P = 0.003). Exploration of mammographic experiences by group found that care taken by technologists in performing or talking women through the exam was higher in adhering women than nonadhering women (75.6% vs 65.71% for performing the exam, and 71.6% vs 60.8% for talking patients through the exam, respectively, P < 0.05).

CONCLUSIONS

The authors found that previous negative mammographic experiences, particularly those involving mammography technologists, appear to influence interval adherence to screening and that patient body size may be an important factor in this negative experience.

Technical skills for weight loss: preliminary data from a randomized trial

BACKGROUND

Optimal behavioral interventions for sustainable weight loss are uncertain. We therefore conducted a study among overweight/obese women comparing conventional dietary counseling of individuals (counseling-based intervention) to a novel, group-based skill-building intervention.

METHODS

Eighty subjects were randomly assigned to either the counseling-based or to the skill-building intervention. Outcomes included weight loss, dietitian hours per group and per unit weight loss, and dollars spent per group and per unit weight lost.

RESULTS

Weight loss at 6 months (follow-up rate 61.3%) in the counseling-based group was 8.8 lb (P = 0.0001), and in the skill-building group was 3.8 lb (P = 0.01). A total of 160 dietitian hours were required for the counseling-based group, and 131 for the skilled-building group. The counseling-based group cost an average of $21 per pound lost, while the skill-building cost an average of $48 per pound lost (P = 0.16).

CONCLUSIONS

At 6 months, individualized office-based counseling produced more weight loss than a skill-building approach and cost less than half as much per pound of weight loss. Longer-term follow-up is required to determine if, as hypothesized, the skill-building intervention produces more sustainable weight loss.

Hormonal regulation of mammary differentiation and milk secretion

The endocrine system coordinates development of the mammary gland with reproductive development and the demand of the offspring for milk. Three categories of hormones are involved. The levels of the reproductive hormones, estrogen, progesterone, placental lactogen, prolactin, and oxytocin, change during reproductive development or function and act directly on the mammary gland to bring about developmental changes or coordinate milk delivery to the offspring. Metabolic hormones, whose main role is to regulate metabolic responses to nutrient intake or stress, often have direct effects on the mammary gland as well. The important hormones in this regard are growth hormone, corticosteroids, thyroid hormone, and insulin. A third category of hormones has recently been recognized, mammary hormones. It currently includes growth hormone, prolactin, PTHrP, and leptin. Because a full-term pregnancy in early life is associated with a reduction in breast carcinogenesis, an understanding of the mechanisms by which these hormones bring about secretory differentiation may offer clues to the prevention of breast cancer.

Green tea extracts decrease carcinogen-induced mammary tumor burden in rats and rate of breast cancer cell proliferation in culture

Epidemiological evidence suggests tea (Camellia sinensis L.) has chemopreventive effects against various tumors. Green tea contains many polyphenols, including epigallocatechin-3 gallate (EGCG), which possess anti-oxidant qualities. Reduction of chemically induced mammary gland carcinogenesis by green tea in a carcinogen-induced rat model has been suggested previously, but the results reported were not statistically significant. Here we have tested the effects of green tea on mammary tumorigenesis using the 7,12-dimethylbenz(a)anthracene (DMBA) Sprague-Dawley (S-D) rat model. We report that green tea significantly increased mean latency to first tumor, and reduced tumor burden and number of invasive tumors per tumor-bearing animal; although, it did not affect tumor number in the female rats. Furthermore, we show that proliferation and/or viability of cultured Hs578T and MDA-MB-231 estrogen receptor-negative breast cancer cell lines was reduced by EGCG treatment. Similar negative effects on proliferation were observed with the DMBA-transformed D3-1 cell line. Growth inhibition of Hs578T cells correlated with induction of p27(Kip1) cyclin-dependent kinase inhibitor (CKI) expression. Hs578T cells expressing elevated levels of p27(Kip1) protein due to stable ectopic expression displayed increased G1 arrest. Thus, green tea had significant chemopreventive effects on carcinogen-induced mammary tumorigenesis in female S-D rats. In culture, inhibition of human breast cancer cell proliferation by EGCG was mediated in part via induction of the p27(Kip1) CKI.

Serum oestradiol in women with carcinomas of the breast and uterine cervix

Endogenous oestrogens are thought to be involved in breast cancer, but few studies could show the direct relationship between hormones and pathological process of the disease. In the present study, oestradiol was estimated in the serum of pre-and postmenopausal breast cancer patients along with normal healthy controls and patients with carcinoma of the uterine cervix which is not dependent on oestrogens. Premenopausal patients with breast cancer showed higher levels of oestradiol as compared to premenopausal control women as well as cervical cancer patients. Whereas, no statistically significant differences were observed in serum oestradiol levels amongst postmenopausal groups of breast cancer, cervical cancer and normal women. The result of the study reflects the association of oestradiol as well as its difference in the pathological events of pre and postmenopausal breast cancer.

Screening for the major malignancies affecting women: current guidelines

Throughout their lifetimes, many women rely on the obstetrician-gynecologist to provide them with regular health care. Therefore the obstetrician-gynecologist should be able to provide comprehensive information regarding consensus screening recommendations for the major malignancies that occur in women. Additionally, a woman's health care provider should continually refine his or her cancer risk--assessment skills and should remain apprised of high-risk habits, family histories, and other cancer-predisposing factors that allow identification of those women in whom heightened surveillance or intervention may be appropriate. This article reviews the epidemiologic and risk factors associated with the major malignancies that affect women today and provides screening guidelines.

Prevalence of gynecologic cancers among female Vietnam veterans

The possibility of a gender-specific health problem associated with the Vietnam War has been a concern since the war. We targeted 4140 female Vietnam veterans and 4140 veteran controls to complete a structured telephone interview that included questions regarding any history of gynecologic cancer. As a measure of association between the risk of cancer and military service in Vietnam, odds ratios and 95% confidence intervals were calculated using multiple logistic regression models that yielded estimates of potential cofounders. Although 8% of Vietnam veterans and 7.1% of non-Vietnam veterans reported a history of gynecologic cancers, namely, breast, ovary, uterus, or cervix, the difference was not statistically significant either for the individual site or for the gynecologic cancers as a group. Female Vietnam veterans have not experienced a higher prevalence of gynecologic cancer in the 30 years since the conflict.

Differential transcriptional activation of peroxisome proliferator-activated receptor gamma by omega-3 and omega-6 fatty acids in MCF-7 cells

While the role of dietary fats in breast cancer remains controversial, the recent cloning of peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor, from human breast cancer cells lines provides a potential molecular link. Several fatty acids from four classes of dietary fats were tested for their ability to mediate the transcriptional activity of PPARgamma in MCF-7 and MDA-MB-231 cells using growth media with minimal serum. Whereas omega-3 fatty acids inhibit transactivation of PPARgamma to levels below control, omega-6, monounsaturated and saturated fatty acids stimulate the activity of the transcriptional reporter. These studies indicate that individual fatty acids differentially regulate the transcriptional activity of PPARgamma by selectively acting as agonists or antagonists. Furthermore, the transcriptional activation of PPARgamma correlates with cell proliferation in MCF-7 cells. Understanding the effects of individual fats on breast cancer cells and PPARgamma transactivation could provide important new insights into the epidemiology of breast cancer and the role of dietary fat.

Use of artificial neural networks in modeling associations of discriminant factors: towards an intelligent selective breast cancer screening

In order to improve the costs/benefits ratio of breast cancer (BC) screenings, the author evaluated the performance of a back-propagation artificial neural network (ANN) to predict an outcome (cancer/not cancer) to be used as classificator. Networks were trained on data from familial history of cancer, and sociodemographic, gynecoobstetric and dietary variables. The ANN achieved up to 94.04% of positive predictive value and 97.60% of negative predictive value. Results could operate as guidelines for preselecting women who would be considered as a BC high-risk subpopulation. The procedure--not only based on age factor, but on a multifactorial basis--appears to be a promising method of achieving a more efficient detection of preclinical, asymptomatic BC cases.

Is there a reduced risk of breast cancer among women with hip fractures?

To test the hypothesis that osteoporosis, which results partly from long-term estrogen deficiency, is associated with a lowered risk of breast cancer, a population-based cohort study was performed in Amiens. To ascertain the incidence of breast cancer, 1300 women were followed through after a first hip fracture. Overall, 18 cases of cancer were observed cf. 21.8 expected (standardized incidence ratio (SIR): 0.82; 95% confidence interval (CI): 0.5-1.3). The results are consistent with previous studies which concluded that long-term estrogen deficiency is associated with a reduced risk of developing breast cancer.

Male breast carcinoma: a review of 229 patients who presented to the Princess Margaret Hospital during 40 years: 1955-1996

BACKGROUND

A single-institution review of clinical presentation, treatment, and outcome of male breast carcinoma was conducted.

METHODS

Data obtained by chart review of 229 cases were analyzed with respect to clinical presentation, treatment choice, significant prognostic factors, and survival. The patients were analyzed both as a single cohort and as four cohorts grouped according to decade of diagnosis.

RESULTS

Presentation occurred at a median age of 63 years, most often with a self-detected lump. Pathology consisted of subtypes similar to those of female breast carcinoma. The majority of tumors were larger than 2 cm in greatest dimension. Lymph node status, hormone receptors, and histologic and nuclear grade were underreported. Primary, adjuvant, and advanced disease treatment practices were reviewed over time. The 5-year disease free survival (DFS), overall survival (OS), and local control were 47%, 53%, and 91%, respectively. No difference in outcome by decade of diagnosis was observed. Negative lymph nodes and adjuvant hormone treatment predicted for better DFS and OS. Younger age and Stage 0 also predicted for better OS.

CONCLUSIONS

Compared with data from female breast carcinoma patients, 5-year OS for this series was low; however, when these patients were separated by lymph node status, survival was similar for those with axillary lymph node metastases. Despite a change in standard primary surgical treatment and an increased use of chemotherapy and hormone therapy over the study period, no difference in outcome was observed among these males. In the absence of prospective, randomized clinical trials, collection of comprehensive data on the presentation and management of male breast carcinoma may help to optimize clinical care.

The quantitative analysis of mammographic densities

Quantitative classification of mammographic parenchyma based on radiological assessment has been shown to provide one of the strongest estimates of the risk of developing breast cancer. Existing classification schemes, however, are limited by coarse category scales. In addition, subjectivity can lead to sizeable interobserver and intraobserver variations. Here, we propose an interactive thresholding technique applied to digitized film-screen mammograms, which assesses the proportion of the mammographic image representing radiographically dense tissue. Observers viewed images on a CRT display and selected grey-level thresholds from which the breast and regions of dense tissue in the breast were identified. The proportion of radiographic density was then calculated from the image histogram. The technique was evaluated for the mammograms of 30 women and is well correlated (R > 0.91, Spearman coefficient) with a six-category subjective classification of radiographic density by radiologists. The technique was found to be very reliable with an intraclass correlation coefficient between observers typically R > 0.9. This technique may have a role in routine mammographic analysis for the purpose of assessing risk categories and as a tool in studies of the etiology of breast cancer, in particular for monitoring changes in breast parenchyma during potential preventive interventions.

Effect of BRCA1 and BRCA2 on the association between breast cancer risk and family history

BACKGROUND

The discovery of BRCA1 and BRCA2 has led to a reassessment of the association between family history of breast/ovarian cancer and breast cancer risk after controlling for carrier status for mutations in the BRCA1 and BRCA2 genes. We examined whether family history of breast cancer remains a predictive risk factor for this disease after carrier status for BRCA1 and/or BRCA2 mutations is taken into consideration.

METHODS

The data are from 4730 case subjects with breast cancer and 4688 control subjects enrolled in the Cancer and Steroid Hormone Study. The probability of being a BRCA1 and/or BRCA2 gene carrier was calculated for each woman. Among predicted noncarriers, logistic regression was used to assess the relationship (odds ratios and 95% confidence intervals [CIs]) between case or control status and family history of breast or ovarian cancer. Estimates of age-specific breast cancer risk are presented by predicted carrier status.

RESULTS

Among predicted noncarriers, case subjects were 2.06 times (95% CI = 1.69-2.50) and 1.24 times (95% CI = 1.17-1.32) more likely to report a first-degree or second-degree family history of breast cancer, respectively, than were control subjects. Case subjects were 1.99 times (95% CI = 1.63-2.44), 1.66 times (95% CI = 1.18-2.38), and 2.23 times (95% CI = 0.21-24.65) more likely to report an affected mother, sister, or both, respectively, than were control subjects. A family history of ovarian cancer was not statistically significantly associated with breast cancer risk. Noncarriers were predicted to have a lifetime risk of 9% of developing breast cancer compared with a 63% risk for carriers.

CONCLUSIONS

Among women with a moderate family history of breast cancer, i.e., predicted noncarriers of BRCA1 and/or BRCA2 mutations, family history remains a factor in predicting breast cancer risk. In families with breast and ovarian cancers, the aggregation of these two cancers appears to be explained by BRCA1/BRCA2 mutation-carrier probability.

Height and breast cancer risk

The relationship between adult height and breast cancer risk was considered, combining data from two case-control studies, one conducted between 1983 and 1991 in northern Italy and the other between 1991 and 1994 in six Italian centres. Cases were 5984 women, below the age of 75 years, with histologically confirmed breast cancer, and controls were 5504 women admitted to hospital for a wide spectrum of acute, non-neoplastic, non-hormone-related diseases. No relationship was observed between height and the risk of breast cancer, with a multivariate odds ratio (OR) of 0.96 (95% confidence intervals (CI) 0.85-1.08) for the tallest women (height > or = 166 cm) compared with the shortest (height < 156 cm). No significant heterogeneity was found across strata of age at diagnosis, education, body mass index, body weight, alcohol intake, age at menarche and menopause, parity, age at first birth, ever use of oral contraceptives and hormone replacement therapy, history of benign breast disease and family history of breast cancer. Thus, this study indicates that adult height is not appreciably related to breast cancer risk in this Italian population.

Breast cancer risk and lifetime occupational history: employment in professional and managerial occupations

OBJECTIVE

In this case-control study, occupational histories were used to assess the relation between risk of breast cancer and employment in professional and managerial occupations while adjusting for reproductive and other risk factors.

METHODS

Incident, primary, female cases of breast cancer diagnosed between 1986 and 1991, and randomly selected controls were interviewed to obtain detailed medical, reproductive, and occupational histories. Mantel-Haenszel crude odds ratios (OR) and 95% confidence intervals (95% CIs) were used to estimate risk of breast cancer related to the job of longest duration. Unconditional logistic regression was used to estimate crude and adjusted ORs and 95% CIs associated with having ever been employed and duration of employment in a professional or managerial occupation.

RESULTS

A non-significant threefold increase in risk was found among premenopausal women whose major job was in the occupational category of precision production, craft, and repair (95% CI 0.90 to 20.35). No increase in risk was found for premenopausal women whose major job was a managerial or professional occupation. However, an inverse relation between risk of premenopausal breast cancer and having ever held a professional or managerial job was observed (OR 0.53, 95% CI 0.34 to 0.82). This relation was strongest for women who worked one to 10 years (OR 0.47, 95% CI 0.29 to 0.77). Postmenopausal breast cancer was not related to professional and managerial employment.

CONCLUSIONS

In this population, employment in professional and managerial occupations is not associated with postmenopausal risk of breast cancer, but seems to be related to a reduction in risk of premenopausal breast cancer. Methodological limitations of this study including response rates are discussed.

Risks of breast and testicular cancers in young adult twins in England and Wales: evidence on prenatal and genetic aetiology

BACKGROUND

Aetiology of breast and testicular cancers may have prenatal factors, possibly exposure of the fetus to high concentrations of maternal oestrogen. Dizygotic twinning probably involves high hormone concentrations, and therefore, dizygotic twins might be at raised risk of these cancers. The aetiologies of breast and testicular cancers have genetic components, for breast cancer, especially at younger ages. Twins of these probands may, therefore, be at high risk. We investigated risk in twins of patients with breast cancer at young ages or with testicular cancer.

METHODS

We identified twins with breast cancer incident at ages younger than 45 years and with incident testicular cancer in England and Wales during 1971-89 by cross-matching national cancer-registration and births records. We determined zygosity by questionnaires to the patients. The twins of probands were followed up for cancer incidence and death. We analysed risks of breast and testicular cancer in dizygotic twins compared with monozygotic twins, and in monozygotic and dizygotic twins of probands.

FINDINGS

We identified 500 twins with breast cancer and 194 with testicular cancer. We found a non-significantly raised risk of breast cancer in dizygotic compared with monozygotic twins younger than 30 years (odds ratio 2.3 [95% CI 0.9-5.9]) but not older. The overall risk of testicular cancer was significantly higher in dizygotic twins than in monozygotic twins (1.5 [1.1-2.2]) consequent on a risk for seminomas was high (3.2 [1.6-6.5]; p = 0.001). Risk of breast cancer was significantly raised in female twins of probands (standardised incidence ratio 7.7 [4.9-12.2], p < 0.001). The relative risk of breast cancer was 34.7 (9.5-126.5) in monozygotic twins of women in whom breast cancer had occurred before age 35 years. The cumulative risk of breast cancer for these twins by age 40 years was 29% (13-56). The relative risk of testicular cancer was 37.5 (12.3-115.6) in twins of men with testicular cancer. The cumulative risk by age 40 years in monozygotic twins of men with testicular cancer was 14% (4-46).

INTERPRETATION

The higher risks of these cancers in dizygotic than in monozygotic twins support a prenatal aetiology, and are compatible with aetiology related to raised maternal concentrations of free, unbound oestrogens. The results for twins of probands have implications for genetic aetiology; appropriate clinical action for monozygotic twins needs consideration.

The relationship between breast asymmetry, breast size and the occurrence of breast cancer

Breast cancer is the second most common cancer among women in the world and in developed countries it is the most common. The early identification of women at risk is therefore of great importance and any additional measures which may aid diagnosis, particularly in high risk groups, would be of benefit. Breast volume and breast asymmetry were calculated from mammograms of 250 women with breast cancer and compared with those of 250 age-matched controls. There was evidence that breast cancer patients had more breast asymmetry and larger breasts than age-matched healthy women. The former observation is the first evidence that high breast asymmetry may be a risk factor for breast cancer. Breast asymmetry is likely to be a predictor of, rather than the effect of breast cancer.

Participation in a breast cancer screening program: influence of past behavior and determinants on future screening participation

BACKGROUND

This study analyzed the relationship between past screening behavior, determinants, intention, and future screening participation in the Dutch national breast cancer screening program.

METHODS

Participation at the first and second screening rounds was monitored. Furthermore, between the first and the second screening rounds, women received a questionnaire (response 58%, n = 395). The questionnaire was based on the ASE model, including attitude (consequences, anticipated regret, and moral obligation), social influence (support and modeling), and self-efficacy. Other distal variables assessed were previous screening behavior, evaluation of screening characteristics, and demographics.

RESULTS

Participants at the second screening differed from nonparticipants on all ASE determinants. Stepwise multiple regression analyses showed that for previous participants and nonparticipants different ASE determinants and distal variables explained the variance in intention to participate in the next screening (30 to 45%). Logistic regression analyses showed that past behavior and intention (which mediated the effects of the ASE variables) were significant predictors of participation in the second screening.

CONCLUSIONS

Differences between previous participants and nonparticipants in determinants of intention and future screening behavior can be used to improve participation and adherence to breast cancer screening.