Recent changes in breast cancer incidence and risk factor prevalence in San Francisco Bay area and California women: 1988 to 2004

Breast Carcinoma Receptor Expression in a Caribbean Population

Trinidad and Tobago are islands in the Southern Caribbean with a unique mix of races within the population consisting of East Indian (EI) (37.6%), Afro-Caribbean (AC) (36.3%), mixed (24.2%), and Caucasian, Chinese, Lebanese, Syrian, Amerindian, and Spanish groups accounting for 1.9%. It makes it suitable for a comparison of breast carcinoma receptor expression within a fixed environment. This study included 257 women with an age range of 28 to 93 years (mean = 57.2, standard deviation = 15.0), peak age group of 51 to 60 consisting of 105 EI, 119 AC, and 33 mixed descent. Invasive ductal carcinoma accounted for 88%, invasive lobular 9.7%, and ductal carcinoma in situ 2.3%. The triple-negative rates were 24.8, 33.6, and 30.3% for EI, AC, and mixed races, respectively, with the Pearson's chi-square test revealing statistical significance for the AC versus EI ( p  < 0.001); AC versus mixed ( p  < 0.001); and EI versus mixed ( p  = 0.014) groups. The overall estrogen (ER), progesterone (PR), and human epidermal growth receptor (HER) expression negative rates were 52, 64, and 79%, respectively. Chi-square test of the following combinations: ER +/PR +/HER + ; ER +/PR +/HER − ; ER −/PR −/HER + ; ER +/PR −/HER + ; ER +/PR −/HER − ; ER −/PR +/HER + ; ER −/PR +/HER− revealed no statistical differences ( p  = 0.689).

Increased Prevalence of Breast and All-cause Cancer in Female Orthopaedic Surgeons

INTRODUCTION

Cancer is the second leading cause of death among women in the United States. Previous studies demonstrate a higher prevalence of cancer among female orthopaedic surgeons. This study aimed to provide an updated prevalence of breast and all-cause cancer among female orthopaedic surgeons using a larger and more current study population.

METHODS

We distributed surveys to female orthopaedic surgeons in national orthopaedic specialty societies. Six hundred seventy-two survey responses were collected. We calculated standardized prevalence ratios (SPRs) and 95% confidence intervals (CIs) based on gender-specific, race-specific, and age-specific cancer prevalence statistics in the US population. We compared the distribution of breast cancer risk factors with that of women in the 2018 and 2009 California Health Interview Survey.

RESULTS

Fifty-one of the 672 surveyed surgeons reported a diagnosis of invasive cancer. Twenty reported breast cancer with a prevalence higher among female orthopaedic surgeons compared with the US female population (SPR: 2.89, 95% CI: 2.16 to 3.81, P < 0.001). The breast cancer prevalence was also higher among orthopaedic surgeons compared with the US female population (SPR: 3.97, 95% CI: 2.43 to 6.14, P = 0.003).

DISCUSSION

The increased prevalence of breast and all-cause cancer among a larger and more diverse cohort of female orthopaedic surgeons confirms previous studies and provides an update regarding a concerning public health issue within this specialty.

Factors associated with locoregional and metastatic breast cancer at diagnosis in a Southern Portuguese registry in the period 2005-2012

Breast cancer (BC) is the most frequent malignancy in Portuguese women, and more than half of the registered cases live in the south of the country. The main of this study was to characterize patients with locoregional and metastatic incident BC living in the Southern Portuguese and Madeira regions in 2005-2012 according to demographic, clinical and contextual characteristics. Additionally it aimns to find the associations and relative influences of these factors with locoregional or metastatic disease at diagnosis. After a descriptive approach, binary logistic regression models were used to estimate factors related to the presence of metastatic disease at diagnosis. A final multiple regression model was developed and presented graphically as a nomogram. The median age at diagnosis was 60.84 years, being statistically lower in locoregional cases (P < 0.001). Most patients presented a locoregional disease (78.4%) of unspecified location (44.5%) and had a ductal carcinoma (73.1%). The Lisbon region represented 50.5% of the analyzed cases. Metastatic disease significantly decreased over the period under analysis ( ≈ 7%/year). Demographic (age at diagnosis ≥ 50 years), clinical (lobular and 'other' morphologies, unspecified location) and contextual (residence in Portalegre) characteristics were statistically correlated with the presence of metastatic disease at the time of BC diagnosis in univariate logistic regression, with all but the last maintaining their significance in a multivariate model. Cases with metastatic BC disease at diagnosis are decreasing; however, additional information on their characteristics can improve the alignment of public health strategies, thus strengthening this trend, and contributing to the development of a graphically tailored screening tool.

KRAS Gene Polymorphisms and their Impact on Breast Cancer Risk in an Iranian Population

Single nucleotide polymorphisms (SNPs) in the let-7 miRNA binding site within the 3’ untranslated region (3’UTR) of KRAS appear related to the risk of cancer. The present case-control study was conducted with 244 BC patients and 204 healthy women to examine whether KRAS polymorphisms (rs61764370 T/G and rs712 G/T) are associated with breast cancer (BC) risk in an Iranian population. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping of KRAS SNPs. Our results showed that the rs61764370 TG genotype (OR= 3.73; 95% CI =1.38-10.08; P=0.007) as well as the G allele OR= 3.56; 95% CI =1.33-9.53; P=0.008, respectively) increased the risk of BC. However, the KRAS rs712 TT vs GG+GT genotype in a recessive model was associated with a reduced risk of BC (OR= 0.56; 95% CI =0.38-0.84; P=0.006). In addition, the rs712 T allele decreased the risk of BC compared with the G allele (OR=0.75, 95%CI=0.58-0.97, P=0.031). However, we found no relationship among KRAS SNPs and clinicopathological characteristics of BC patients (P>0.05). Taken together, the present study provided evidence of relationships between KRAS polymorphisms and BC risk in a southeast Iranian population. Additional studies using larger sample sizes and diverse ethnicities are now warranted.

Breast cancer in systemic lupus

Objective There is a decreased breast cancer risk in systemic lupus erythematosus (SLE) versus the general population. We assessed a large sample of SLE patients, evaluating demographic and clinical characteristics and breast cancer risk. Methods We performed case-cohort analyses within a multi-center international SLE sample. We calculated the breast cancer hazard ratio (HR) in female SLE patients, relative to demographics, reproductive history, family history of breast cancer, and time-dependent measures of anti-dsDNA positivity, cumulative disease activity, and drugs, adjusted for SLE duration. Results There were 86 SLE breast cancers and 4498 female SLE cancer-free controls. Patients were followed on average for 7.6 years. Versus controls, SLE breast cancer cases tended to be white and older. Breast cancer cases were similar to controls regarding anti-dsDNA positivity, disease activity, and most drug exposures over time. In univariate and multivariate models, the principal factor associated with breast cancers was older age at cohort entry. Conclusions There was little evidence that breast cancer risk in this SLE sample was strongly driven by any of the clinical factors that we studied. Further search for factors that determine the lower risk of breast cancer in SLE may be warranted.

The effects of spiritual intervention and changes in dopamine receptor gene expression in breast cancer patients

Breast cancer is the most common cancer in females in Iran and in most of the developed countries. Studies have shown that having chronic stress in individuals predisposes several types of cancer including breast cancer. Research results showed that spiritual factors correlate with indices of physical consequences such as heart disease, cancer, and death, so do psychiatric conditions and changes in receptor gene expression in depression, anxiety, and social dysfunction. Different studies demonstrated the role of neurotransmitters in occurrence and progression of cancers. They affected cells by their various types of receptors. An effective gene in mental and physical conditions is Dopamine receptor. Accordingly, the study was conducted to evaluate effects of psychotherapy (spiritual intervention) on changes in Dopamine receptor gene expressions in breast cancer patients. 90 female volunteers, including 30 healthy individuals and 60 diagnosed with breast cancer, considering exclusion criteria, were selected for the purpose of the study. The breast cancer patients were further categorized into experimental and control groups of 30 each. Blood samples were collected both prior to and following the spiritual intervention to analyze changes in their dopamine gene receptor expressions. We observed that DRD2-DRD4 in the control group (breast cancer patients) PBMC increased compared to healthy individuals. Also, DRD2-DRD4 in intervention group PBMC decreased compared to the control group and to even lower than those of healthy individuals. The findings were of great significance in management and treatment of cancer because they revealed the possibility of using alternative treatments (e.g., spiritual interventions) apart from conventional medical treatments.

Preventing breast cancer now by acting on what we already know

The age-specific rate of breast cancer rises rapidly through premenopausal years and significantly more slowly after menopause. Reproductive factors affect cell proliferation and the accumulation of genetic changes. Lifetime risk of breast cancer is linearly related to the length of the interval from menarche to first birth. Lifestyle changes that accompany industrialization, together with shifting reproductive patterns, drive up incidence rates. Prevention must begin early in the life as almost one-quarter of cases are diagnosed before age 50 in high-income countries. This requires greater emphasis on prevention across the life course to address the global burden of breast cancer.

Disaggregating data on Asian American and Pacific Islander women to provide new insights on potential exposures to hazardous air pollutants in California

BACKGROUND

The Asian American and Pacific Islander (AAPI) population is heterogeneous and rapidly growing in the United States, with a high proportion concentrated in California. Although traditionally assumed to have lower rates of breast cancer than non-Hispanic white women, recent studies have suggested considerable variation in incidence by AAPI ethnic group, with rates in some exceeding those in non-Hispanic whites. The potential role of environmental toxicants has not been well explored and may provide insights into these patterns.

METHODS

We created an exposure potential index (EPI) score for 24 hazardous air pollutants modeled by the U.S. Environmental Protection Agency National-Scale Air Toxics Assessment considered to be mammary gland carcinogens, and compared values at the census tract level for "geographically concentrated" AAPI groups throughout the State. "Geographically concentrated" populations were defined as census tracts with at least 100 individuals from a specified racial/ethnic population as enumerated by the 2000 Census.

RESULTS

Although EPI scores differed little between census tracts with aggregated AAPI (mean EPI = 0.53) and non-Hispanic white women (mean EPI = 0.63), there was substantial variation between tracts for disaggregated AAPI groups, with notably higher EPI scores for tracts enumerated for Korean or Japanese women (mean EPI of 0.78 and 0.77, respectively) compared with other AAPI groups.

CONCLUSIONS

Our findings underscore the importance of disaggregating data for the heterogeneous AAPI population to identify differences in potential environmental exposures across groups.

IMPACT

Future cancer etiology studies should examine environmental exposure differences within and across groups for the diverse AAPI population.

Effect of TP53 16-bp and β-TrCP 9-bp INS/DEL polymorphisms in relation to risk of breast cancer

P53 as a tumor suppressor and an apoptosis modulator, is the regulator of the cell cycle and apoptosis, and contributes to mammary gland development and breast cancer (BC) progression. BTRC gene (Homo sapiens beta-transducing repeat containing E3 ubiquitin protein ligase) encoded protein, β-TrCP, is a novel regulator of p53. The current study aimed to assess the possible effects of TP53 IVS3 16 bp (rs17878362) and β-TrCP 9 bp (rs16405) INS/DEL polymorphisms on BC risk in an Iranian population. A total of 439 women including 236 BC patients and 203 healthy women were recruited. The TP53 and β-TrCP INS/DEL polymorphisms were genotyped by allele-specific polymerase chain reaction method. Our data demonstrated that the TP53 16-bp INS/DEL variation was associated with an increased risk of BC in codominant (INS/INS vs.

DEL/DEL

OR=1.82; 95% CI=1.02-3.23; P=0.042) and dominant (Del/INS+INS/INS vs.

DEL/DEL

OR=1.48; 95% CI=1.03-2.21; P=0.044) models. Additionally, the variant allele (INS) of TP53 DEL/INS polymorphism with a relatively higher frequency in cases than in controls (35.6 vs. 27.8) was a risk factor for BC (OR=1.43; 95% CI=1.06-1.93; P=0.017). With respect to β-TrCP INS/DEL polymorphism, our study failed to find any difference in allele and genotype distribution between BC patients and controls in codominant, dominant and recessive tested inheritance models (P>0.05). Furthermore, no significant association among the β-TrCP and TP53 genotype distribution and clinical characteristics of BC patients were found (P>0.05). Our findings suggest that the TP53 16-bp INS/INS and DEL/INS+INS/INS genotypes as well as the INS allele could be genetic factors related to BC risk.

Menopausal hormone therapy use in 17 European countries during the last decade

INTRODUCTION

The first 'Women's Health Initiative' (WHI) randomised controlled trial assessed use of continuous combined menopausal hormone therapy (cc-MHT). It was prematurely stopped because of an increased invasive breast cancer (BC), coronary heart disease (CHD), stroke and pulmonary embolism risk. Consequently, scientific societies recommended use of MHT at the lowest effective dose for the shortest duration. As a result, a sharp decline in MHT use occurred worldwide.

AIM

To report in a uniform way the change in MHT use in European countries. To evaluate whether the variability of the MHT changes were related to some medical indicators.

MATERIALS AND METHODS

IMS Health provided MHT sales data for the years 2002 till 2010 for 17 countries. We tested several hypotheses to explain the heterogeneity of MHT use changes.

RESULTS AND DISCUSSION

In 2002, the estimated MHT rate in women 45-69 years old varied considerably between countries ranging from less than 5% to more than 25%. In all countries a profound decrease occurred between 2002 and 2010, ranging from 50% to 77%. By the end of 2010, the MHT uptake was lower than 10% in all countries except in Finland. MHT use change was not correlated to MHT use and prevailing BC incidence at baseline, nor to the number of gynaecologists per 100,000 women or to the level of information about MHT.

CONCLUSION

The global MHT use experienced a sharp decrease in all the analysed countries, although some variability exists. The decrease was unrelated to the assessed parameters.

Assessing breast cancer risk models in Marin County, a population with high rates of delayed childbirth

INTRODUCTION

This study was designed to compare the Breast Cancer Risk Assessment Tool (BCRAT; Gail), International Breast Intervention Study (IBIS; Tyrer-Cuzick), and BRCAPRO breast cancer risk assessment models using data from the Marin Women's Study, a cohort of women within Marin County, California, with high rates of breast cancer, nulliparity, and delayed childbirth. Existing models have not been well-validated in these high-risk populations.

METHODS

Discrimination was assessed using the area under the receiver operating characteristic curve (AUC) and calibration by estimating the ratio of expected-to-observed (E/O) cases. The models were assessed using data from 12,843 participants, of whom 203 had developed cancer during a 5-year period. All tests of statistical significance were 2-sided.

RESULTS

The IBIS model achieved an AUC of 0.65 (95% confidence interval [CI], 0.61-0.68) compared with 0.62 (95% CI, 0.59-0.66) for BCRAT and 0.60 (95% CI, 0.56-0.63) for BRCAPRO. The corresponding estimated E/O ratios for the models were 1.08 (95% CI, 0.95-1.25), 0.81 (95% CI, 0.71-0.93), and 0.59 (95% CI, 0.52-0.68). In women with age at first birth > 30 years, the AUC for the IBIS, BCRAT, and BRCAPRO models was 0.69 (95% CI, 0.62-0.75), 0.63 (95% CI, 0.56-0.70), and 0.62 (95% CI, 0.56-0.68) and the E/O ratio was 1.15 (95% CI, 0.89-1.47), 0.81 (95% CI, 0.63-1.05), and 0.53 (95% CI, 0.41-0.68), respectively.

CONCLUSIONS

The IBIS model was well calibrated for the high-risk Marin mammography population and demonstrated the best calibration of the 3 models in nulliparous women. The IBIS model also achieved the greatest overall discrimination and displayed superior discrimination for women with age at first birth > 30 years.

Systematic review about breast cancer incidence in relation to hormone replacement therapy use

BACKGROUND

Several studies report a decrease in breast cancer incidence subsequent to the decrease in hormone replacement therapy (HRT) use. But its magnitude and the time-lag may vary between countries. This may reflect differences in populations, previous type and prevalence of HRT use and breast cancer screening.

AIM

To review systematically studies assessing the relation between breast cancer incidence and change of HRT use.

MATERIAL AND METHOD

Descriptive analysis of the methodology of the studies including design limitations and presence of confounding factors, data sources for breast cancer and HRT and regimens of HRT used.

RESULTS AND DISCUSSION

Eighteen articles were selected. Most studies were ecological and confounding factors such as mammography screening and changes in reproductive and lifestyle habits could not be excluded. Sources of data on breast cancer and HRT were heterogeneous and only few data on HRT regimens used were available. Most studies concluded that the decrease in HRT use during the last decade was probably associated with a decrease in breast cancer incidence, especially for women aged 50 years or more.

CONCLUSIONS

Data, mostly from epidemiological studies, suggest that the decrease in breast cancer incidence can be partly attributed to the drop in HRT use. Nevertheless, available studies are hampered by a number of limitations and it remains difficult to evaluate the exact impact of the drop in HRT use on the decrease in breast cancer incidence. Especially, the studies are seldom based on detailed individual data and do not provide information on regimens used, type of cancers and possible confounding factors.

A Population-Based Observational Study of First-Course Treatment and Survival for Adolescent and Young Adult Females with Breast Cancer

PURPOSE

Young age at breast cancer diagnosis is associated with poor survival. However, little is known about factors associated with first-course treatment receipt or survival among adolescent and young adult (AYA) females aged 15-39 years.

METHODS

Data regarding 19,906 eligible AYA breast cancers diagnosed in California during 1992-2009 were obtained from the population-based California Cancer Registry. Multivariable logistic regression was used to evaluate clinical and sociodemographic differences in treatment receipt. Multivariable Cox proportional hazards regression was used to examine differences in survival by initial treatment, and by patient and tumor characteristics.

RESULTS

Black and Hispanic AYAs diagnosed with in situ or stages I-III breast cancer were more likely than White AYAs to receive breast-conserving surgery (BCS) without radiation; Asian and Hispanic AYAs were more likely than Whites to receive mastectomy. Women in lower socioeconomic status (SES) neighborhoods were more likely to omit radiation after BCS, more likely to receive mastectomy, and less likely to receive chemotherapy, compared to those in higher SES neighborhoods. Among patients with invasive disease, survival improved an average of 5% per year during 1992-2009. AYAs who received BCS with radiation experienced better survival than other surgery/radiation options. Black AYAs had poorer survival than Whites. AYAs who resided in higher SES neighborhoods had better survival.

CONCLUSIONS

Treatment receipt among AYAs with breast cancer varied by race/ethnicity and neighborhood SES. Poor survival for Black AYAs and AYAs living in low SES neighborhoods in models adjusted for treatment receipt suggests that factors other than treatment may also be important to disease outcome.

Prevalence of breast cancer in a defined population of iran

Background

Prevalence of breast cancer in Asian developing countries is much lower than western developed countries. The main aim of this study was to measure breast cancer prevalence in a defined population of Iran.

Methods

A total of 25201 women who were under coverage of “Imam Khomeini Relief Foundation (IKRF)”, which is an organization for delivering supportive social and cultural services to the deprived and poor subgroups of the society, were involved in the study. The study was conducted during years 2007 and 2008. All subjects were interviewed for their socio-demographic features and underwent precise clinical and para-clinical breast examination.

Results

Mean age was 47 years with standard deviation 10 ranging from 11 to 88 years. Subjects were from deprived subgroups of the community; were mainly illiterate or had primary school education (86%) and majority of them (93%) had their first full-term pregnancy at age less than 26 years and also were multiparous. With confirmed diagnosis by breast biopsy, breast cancer prevalence was 0.15% (95%CI; 0.10-0.20).

Conclusion

Compared with developed countries, Asian developing countries have been at a lower risk of breast cancer development. It is seen that more deprived subgroups are at much lower risk. The more industrialized life is accompanied with more hazards.

Power of tests for comparing trend curves with application to national immunization survey (NIS)

To develop statistical tests for comparing trend curves of study outcomes between two socio-demographic strata across consecutive time points, and compare statistical power of the proposed tests under different trend curves data, three statistical tests were proposed. For large sample size with independent normal assumption among strata and across consecutive time points, the Z and Chi-square test statistics were developed, which are functions of outcome estimates and the standard errors at each of the study time points for the two strata. For small sample size with independent normal assumption, the F-test statistic was generated, which is a function of sample size of the two strata and estimated parameters across study period. If two trend curves are approximately parallel, the power of Z-test is consistently higher than that of both Chi-square and F-test. If two trend curves cross at low interaction, the power of Z-test is higher than or equal to the power of both Chi-square and F-test; however, at high interaction, the powers of Chi-square and F-test are higher than that of Z-test. The measurement of interaction of two trend curves was defined. These tests were applied to the comparison of trend curves of vaccination coverage estimates of standard vaccine series with National Immunization Survey (NIS) 2000-2007 data.

Is the decrease in breast cancer incidence related to a decrease in postmenopausal hormone therapy?

Following the Women's Health Initiative (WHI) publication in mid 2002, a drastic decrease in hormone therapy for postmenopausal women has been observed worldwide. Since 2007, the reported incidence in breast cancer has declined. Most authors have linked this decline to the reduction in hormone treatment. In this paper we discuss why these ecological observations are not fully convincing and focus on the importance of screening and variations in other risk factors to interpret this decline in breast cancer.

Breast cancer incidence patterns among California Hispanic women: differences by nativity and residence in an enclave

BACKGROUND

Breast cancer incidence is higher in U.S.-born Hispanic women than foreign-born Hispanics, but no studies have examined how these rates have changed over time. To better inform cancer control efforts, we examined incidence trends by nativity and incidence patterns by neighborhood socioeconomic status (SES) and Hispanic enclave (neighborhoods with high proportions of Hispanics or Hispanic immigrants).

METHODS

Information about all Hispanic women diagnosed with invasive breast cancer between 1988 and 2004 was obtained from the California Cancer Registry. Nativity was imputed from Social Security number for the 27% of cases with missing birthplace information. Neighborhood variables were developed from Census data.

RESULTS

From 1988 to 2004, incidence rates for U.S.-born Hispanics were parallel but lower than those of non-Hispanic whites, showing an annual 6% decline from 2002 to 2004. Foreign-born Hispanics had an annual 4% increase in incidence rates from 1995 to 1998 and a 1.4% decline thereafter. Rates were 38% higher for U.S.- than foreign-born Hispanics, with elevations more pronounced for localized than regional/distant disease, and for women>50 years of age. Residence in higher SES and lower Hispanic enclave neighborhoods were independently associated with higher incidence, with Hispanic enclave having a stronger association than SES.

CONCLUSIONS

Compared with foreign-born, U.S.-born Hispanic women in California had higher prevalence of breast cancer risk factors, suggesting that incidence patterns largely reflect these differences in risk factors.

IMPACT

Further research is needed to separate the effects of individual- and neighborhood-level factors that affect incidence in this large and growing population.

Differences in reproductive risk factors for breast cancer in middle-aged women in Marin County, California and a sociodemographically similar area of Northern California

Background

The Northern California county of Marin (MC) has historically had high breast cancer incidence rates. Because of MC's high socioeconomic status (SES) and racial homogeneity (non-Hispanic White), it has been difficult to assess whether these elevated rates result from a combination of established risk factors or other behavioral or environmental factors. This survey was designed to compare potential breast cancer risks and incidence rates for a sample of middle-aged MC women with those of a demographically similar population.

Methods

A random sample of 1500 middle-aged female members of a large Northern California health plan, half from Marin County (MC) and half from a comparison area in East/Central Contra Costa County (ECCC), were mailed a survey covering family history, reproductive history, use of oral contraceptives (OC) and hormone replacement therapy (HRT), behavioral health risks, recency of breast screening, and demographic characteristics. Weighted data were used to compare prevalence of individual breast cancer risk factors and Gail scores. Age-adjusted cumulative breast cancer incidence rates (2000–2004) were also calculated for female health plan members aged 40–64 residing in the two geographic areas.

Results

Survey response was 57.1% (n = 427) and 47.9% (n = 359) for MC and ECCC samples, respectively. Women in the two areas were similar in SES, race, obesity, exercise frequency, current smoking, ever use of OCs and HRT, age at onset of menarche, high mammography rates, family history of breast cancer, and Gail scores. However, MC women were significantly more likely than ECCC women to be former smokers (43.6% vs. 31.2%), have Ashkenazi Jewish heritage (12.8% vs. 7.1%), have no live births before age 30 (52.7% vs. 40.8%), and be nulliparous (29.2% vs. 15.4%), and less likely to never or rarely consume alcohol (34.4% vs. 41.9%). MC and ECCC women had comparable 2000–2004 invasive breast cancer incidence rates.

Conclusion

The effects of reproductive risks factors, Ashkenazi Jewish heritage, smoking history, and alcohol consumption with regard to breast cancer risk in Marin County should be further evaluated. When possible, future comparisons of breast cancer incidence rates between regions should adjust for differences in income and education in addition to age and race/ethnicity, preferably by using a sociodemographically similar comparison group.

Decline in hormone replacement prescription and fall in breast cancer incidence: an epidemiological discourse

INTRODUCTION

Between 2002 and 2003 the incidence of invasive breast cancer among women aged 50 to 69 years declined considerably in the US. This decline was accompanied by a substantial fall in prescription rates of estrogen-progestin (EG-HRT).

METHODS

Selective literature search in PubMed from 01/2003 to 12/2007 using the key words "hormone replacement therapy," "incidence," and "breast cancer."

RESULTS

The parallel decline in EG-HRT and breast cancer suggests a causal link. Up to now, alternative explanations for the decline of the incidence can either be refuted or revealed as implausible.

DISCUSSION

Detailed incidence trend analyses in the coming years and a close monitoring of EG-HRT prescription rates in and beyond the US. promise important insights. If EG-HRTs are carcinogenic, the extent of this effect remains unclear. If cessation of EG-HRT therapy only delays the appearance of detectable breast cancer, a long-term increase in incidence would be expected in women of age 50 and older, even with low prescription rates. However, if cessation of EG-HRT also stops tumor growth, the anticipated incidence will be permanently lower in the future.