Local Breast Cancer Spatial Patterning: A Tool for Community Health Resource Allocation to Address Local Disparities in Breast Cancer Mortality

Despite available demographic data on the factors that contribute to breast cancer mortality in large population datasets, local patterns are often overlooked. Such local information could provide a valuable metric by which regional community health resources can be allocated to reduce breast cancer mortality. We used national and statewide datasets to assess geographical distribution of breast cancer mortality rates and known risk factors influencing breast cancer mortality in middle Tennessee. Each county in middle Tennessee, and each ZIP code within metropolitan Davidson County, was scored for risk factor prevalence and assigned quartile scores that were used as a metric to identify geographic areas of need. While breast cancer mortality often correlated with age and incidence, geographic areas were identified in which breast cancer mortality rates did not correlate with age and incidence, but correlated with additional risk factors, such as mammography screening and socioeconomic status. Geographical variability in specific risk factors was evident, demonstrating the utility of this approach to identify local areas of risk. This method revealed local patterns in breast cancer mortality that might otherwise be overlooked in a more broadly based analysis. Our data suggest that understanding the geographic distribution of breast cancer mortality, and the distribution of risk factors that contribute to breast cancer mortality, will not only identify communities with the greatest need of support, but will identify the types of resources that would provide the most benefit to reduce breast cancer mortality in the community.     

Immediate breast reconstruction with saline-filled implants: no interference with the oncologic outcome?

The possible adverse effects on cancer control due to immediate breast reconstruction have been addressed recently for both silicone-filled implants and flap reconstruction. To evaluate those possible effects after immediate breast reconstruction with saline-filled implants, 49 patients reconstructed with saline-filled breast implants at the Jules Bordet Cancer Institute were studied. Selection was only based on the possibility to find a matched patient. These patients were matched with a control group of 49 matched women with breast cancer treated in the same center by mastectomy without any type of breast reconstruction. The two groups were comparable according to age at diagnosis (within 3 years), year of diagnosis (same year), stage of the tumor, histology, and nodal status. The only difference between the two groups was that radiation therapy was applied to some of the patients who were not reconstructed (due to tumor location). The results show, in terms of local recurrences, distant metastasis, and deaths, no significant difference between the two groups, even for the irradiated patients, within a mean follow-up period of 72 months (range, 24 to 108) months.     

Differences in cancer incidence by age at diagnosis between Aboriginal and non-Aboriginal people for cancer types included in Australian national screening programs

BackgroundThis study examined age distributions and age-specific incidence of screened cancers by Aboriginal status in New South Wales (NSW) to consider the appropriateness of screening target age ranges.MethodsThe NSW Cancer Registry identified invasive (female) breast, cervical and bowel cancers in people diagnosed in 2001–2014.ResultsAboriginal people were younger at diagnosis with higher proportions of breast and bowel cancers diagnosed before the screening target age range (<50 years) compared with non-Aboriginal people (30.6% vs. 22.8%, and 17.3% vs. 7.3%, respectively). Age-specific incidence rate ratios (IRRs) were lower/similar for breast and bowel cancers in younger and higher in older Aboriginal than non-Aboriginal people. All age-specific cervical cancer IRRs were higher for Aboriginal compared with non-Aboriginal people.ConclusionAlthough higher proportions of breast and colorectal cancers were diagnosed before screening commencement age in Aboriginal people, this does not necessarily indicate a need for earlier screening commencement. Other aspects needing consideration include benefits, harms and cost-effectiveness.     

Occult breast carcinoma in reduction mammaplasty specimens: 14-year experience

Reduction mammaplasty is commonly performed for bilateral macromastia, congenital asymmetry, or as a contralateral symmetry procedure in breast reconstruction following mastectomy for cancer. Occult carcinoma has been detected in 0.06 percent to 0.4 percent of breast reduction specimens. The purpose of this study was to examine the incidence of breast cancer in breast reductions performed in one institution over a 14-year period. The authors reviewed their experience with 800 reduction mammaplasties performed between 1988 and 2001. Six cancers were detected (0.8 percent). Of these cancers, three were invasive (0.4 percent) and three were ductal carcinoma in situ (0.4 percent). Stratified by indication for surgery, there was a trend toward higher detection rates in the reconstruction group (1.2 percent) compared with the macromastia (0.7 percent) or congenital asymmetry (0 percent) groups. Mammography was performed preoperatively in these patients and all results were negative for masses or suspicious microcalcification. Pathological diagnosis was guided by gross specimen evaluation in two patients and specimen radiography in one patient. Reduction mammaplasty has a small but definite risk of finding cancer in the resection specimen.     

Prophylactic mastectomy: indications, options, and reconstructive alternatives

Prophylactic mastectomy continues to be a controversial procedure as a preventive tool against breast cancer. Recent research and other scientific advances, however, have refocused attention on better risk estimation, evidence of efficacy, and improvements in reconstruction. The recently discovered genetic markers BRCA1 and BRCA2 have become increasingly important in determining risk; a BRCA1-positive patient's risk of developing breast cancer by the age of 65 is estimated at 50 percent to 80 percent. BRCA1- and BRCA2-positive breast cancers also tend to be higher grade and occur in younger women (making mammography less effective). Genetically linked breast cancers are usually estrogen receptor negative, making them less susceptible to chemoprevention. Various predictive models and recommendations by experts in the field are also available for today's clinicians to ascertain who should be genetically tested. The benefit of bilateral prophylactic mastectomy, although difficult to estimate, can be evaluated by looking at the incidence of breast cancer in studies of patients who have previously undergone prophylactic mastectomy. The estimated risk reduction from these studies is 80 percent to 95 percent. Similarly, life expectancy is believed to be increased from 2.9 to 5.3 years. The psychological benefits include a 70 percent rate of satisfaction and a decrease in emotional concern over developing breast cancer by 74 percent of women who underwent prophylactic mastectomy. Although reconstruction results may vary, most patients have been very satisfied and some may achieve cosmetic results that are better than their preoperative situation. Patient selection for specific types of reconstruction after prophylactic mastectomy and the decision to proceed should be based on surgical risk and the likelihood of a good outcome. The choice of mastectomy incision should consider the size of the breast, preexisting scars, patient risk factors, and the planned method and goal of reconstruction. The authors propose certain guidelines based on degree of ptosis and cup size when planning prophylactic mastectomies with reconstruction. In certain cases, a nipple-sparing mastectomy may provide cosmetic advantages that could outweigh the additional oncologic risk.     

Cancer incidence in Nigeria: A report from population-based cancer registries

Introduction: Cancer has become a major source of morbidity and mortality globally. Despite the threat that cancer poses to public health in sub-Saharan Africa (SSA), few countries in this region have data on cancer incidence. In this paper, we present estimates of cancer incidence in Nigeria based on data from 2 population-based cancer registries (PBCR) that are part of the Nigerian national cancer registry program. Materials and methods: We analyzed data from 2 population based cancer registries in Nigeria, the Ibadan Population Based Cancer Registry (IBCR) and the Abuja Population Based Cancer Registry (ABCR) covering a 2 year period 2009-2010. Data are reported by registry, gender and in age groups. We present data on the age specific incidence rates of all invasive cancers and report age standardized rates of the most common cancers stratified by gender in both registries. Results: The age standardized incidence rate for all invasive cancers from the IBCR was 66.4 per 100000 men and 130.6 per 100000 women. In ABCR it was 58.3 per 100000 for men and 138.6 per 100000 for women. A total of 3393 cancer cases were reported by the IBCR. Of these cases, 34% (1155) were seen among males and 66% (2238) in females. In Abuja over the same period, 1128 invasive cancers were reported. 33.6% (389) of these cases were in males and 66.4% (768) in females. Mean age of diagnosis of all cancers in men for Ibadan and Abuja were 51.1 and 49.9 years respectively. For women, mean age of diagnosis of all cancers in Ibadan and Abuja were 49.1 and 45.4 respectively. Breast and cervical cancer were the commonest cancers among women and prostate cancer the most common among men. Breast cancer age standardized incidence rate (ASR) at the IBCR was 52.0 per 100000 in IBCR and 64.6 per 100000 in ABCR. Cervical cancer ASR at the IBCR was 36.0 per 100000 and 30.3 per 100000 at the ABCR. The observed differences in incidence rates of breast, cervical and prostate cancer between Ibadan and Abuja, were not statistically significant. Conclusion: Cancer incidence data from two population based cancer registries in Nigeria suggests substantial increase in incidence of breast cancer in recent times. This paper highlights the need for high quality regional cancer registries in Nigeria and other SSA countries.     

Women cancers in India: Incidence,trends and their clinical extent from the National Cancer Registry Programme

BackgroundTo provide a comprehensive assessment of women cancer in India utilizing the systematically collected data on all cancers by the National Cancer Registry Programme (NCRP).MethodsThe study examined 10,2287 cancer cases among women cancers providing cancer burden for major anatomical sites. Aggregated data of 28 PBCRs and 58 HBCRs under NCRP for 2012–16 was analysed for incidence rates, trends, cumulative risk of developing cancer, stage at detection and treatments offered.ResultsStudy results have found region –wide variation of women cancers by indicating highest proportions in western followed by southern region of India. North-Eastern region had lowest proportion. It was observed that breast is highest ranking cancer in most registry areas of urban agglomerations of country while cancer cervix was leading site in registries of rural areas like Barshi (15.3) and Osmanabad &Beed (13.1). States of Mizoram (23.2) and Tripura (9.5) along with Pasighat, Cachar and Nagaland. Median age of occurrence for women for these anatomical sites ranged from 45 to 60 years of age. For cancer breast, cervix and ovary –most cases were detected with regional spread. These findings were different for cancer corpus uteri where registries have reported higher proportions (49.3 %) of localized stage at detection. Loco regional cancers had higher proportions of multimodality treatments.ConclusionStudy provides a foundation for assessing the status of women cancers in the country. Variations between geographies would guide appropriate support for action to strengthen efforts to improve cancer prevention and control in underserved areas of the country. This would facilitate advocacy for better investments and research on women cancers.     

Age-associated biomarker profiles of human breast cancer

To explore the hypothesis that aging not only increases breast cancer incidence but also alters breast cancer biology, we correlated patient age and diagnosis with tumor histology, stage and biomarkers independently determined from two different tumor archives: an American collection of approximately 800 paraffin-embedded and immunohistochemically analyzed primary breast cancers, and an European collection of approximately 3000 cryobanked primary breast cancers analyzed by ligand-binding and enzyme immunoassay (EIA). The prognostic biomarkers chosen for comparison represented surrogate measures of tumor: (i). proliferation, growth and genetic instability (mitotic and apoptotic indices, Ki-67/MIB-1-positivity, nuclear grade, p53-positivity), (ii). endocrine-dependence (estrogen receptor (ER), progesterone receptors (PR), pS2, Bcl2), (iii). growth factor receptor-dependence (ErbB2, EGFR/ErbB1), and (iv). angiogenic, invasive and proteolytic potential (uPA, PAI-1, Cathepsin D, VEGF). No biomarker reflecting tumor angiogenic, invasive or proteolytic potential showed a significant correlation with patient age at diagnosis. In contrast, significant inverse correlations (|r|>0.1; P< or =0.05) were observed for all measures of tumor growth and genetic instability as well as growth factor receptor overexpression (ErbB2 or EGFR positivity). Only one marker of endocrine-dependence, ER expression, showed a significant positive correlation with patient age at diagnosis. In summary, these findings support the hypothesis that breast cancer biology is significantly affected by patient age. In particular, breast tumors arising in older patients have slower growth rates, are more likely to be ER-positive, and are less likely to be p53-positive, EGFR-positive or ErbB2-positive.     

Surgical Management for Early-Stage Bilateral Breast Cancer Patients in China

Background

The aim of this study was to investigate the current surgical management strategy for bilateral breast cancer (BBC) patients and to assess the changes in this strategy in China.

Methods

This is a retrospective review of all patients with early-stage BBC who underwent surgical treatment at the Fudan University Shanghai Cancer Center between June 2007 and June 2014.

Results

A total of 15,337 patients with primary breast cancer were identified. Of these patients, 218 (1.5%) suffered from synchronous bilateral breast cancer (sBBC), and 296 (2.0%) suffered from metachronous bilateral breast cancer (mBBC). Patients with a lobular carcinoma component, those with estrogen receptor-positive cancer, and those with an accompanying sclerosing adenosis in the affected breast tended to develop BBC. The rates of bilateral mastectomy, breast conserving therapy, reconstruction, and combined surgeries were 86.2%, 6.4%, 3.7%, and 3.7%, respectively, for patients with sBBC and 81.1%, 4.4%, 3.0%, and 11.5%, respectively, for patients with mBBC. The interval between bilateral cancers, age at first diagnosis of breast cancer, histopathological type, and stage have significant impacts on the choice of surgery for patients with BBC.

Conclusions

Bilateral mastectomy was the dominant surgical management for patients with BBC in China, despite the increased application of breast reconstruction surgery observed in recent years. Bilateral prosthetic breast reconstruction was the ideal choice for patients with sBBC. Chinese surgeons should take responsibility for patient education and inform their patients about their surgical options.     

Are prognostic factors more favorable for breast cancer detected by organized screening than by opportunistic screening or clinical diagnosis? A study in Loire-Atlantique (France)

Purpose: Comparisons of breast cancer characteristics between organized and opportunistic screening have been limited. This study was designed to compare characteristics of cancers detected by either organized or opportunistic screening as well as clinically diagnosed cancers in Loire-Atlantique (a French administrative entity), from 2003 to 2007. Methods: This study is based on data from the population-based Loire-Atlantique Cancer Registry. Stage at diagnosis and prognostic characteristics of carcinomas detected by organized screening were compared, by age-adjusted logistic regressions, to those of cancers detected by opportunistic screening and diagnosed clinically. Analyses were restricted to women aged 50–74 years (the age group targeted by the organized screening program) for the 2003–2007 period. Results: Between 2003 and 2007, 2864 invasive and 400 in situ breast cancer cases were diagnosed in women aged 50–74 years in Loire-Atlantique. Compared to cancers diagnosed clinically, cancers detected by organized screening were more likely to be in situ (13.7% vs. 3.8%), diagnosed at an early stage (74.4% vs. 51.3%), have a low SBR grade (grade 1: 35.4% vs. 18.5%), and be positive for estrogen–progesterone receptors (68.3% vs. 59.0%). The distribution of stage at diagnosis and prognostic characteristics between organized and opportunistic screening were similar. Conclusion: These findings are consistent with the hypothesis that breast cancers are detected early by organized screening. Cancer characteristics were similar between the two screening modes. Estimating the impact of mammography screening on mortality in Loire-Atlantique should be the object of further investigations.     

A follow-up study of 105 women with breast cancer following reduction mammaplasty.

Reduction mammaplasty is one of the most common procedures performed by plastic surgeons in Canada. In a recent study of 27,500 women in the province of Ontario who underwent breast reduction surgery, 105 women were identified who developed breast cancer after reduction mammaplasty. The purpose of this study was to compare women who had breast cancer and had a previous breast reduction with women who had breast cancer but did not have a breast reduction. Specifically, we wanted to document patient demographics, cancer type, surgical and nonsurgical treatment, and eventual outcome. A comparison group of non-breast reduction women was taken from the cohort of breast cancer patients in the province of Ontario, and the two groups were matched for age, year of diagnosis, and place of diagnosis. It was found that (1) the average age at diagnosis of breast cancer is significantly younger for women who have had previous breast reduction surgery than for those who have not; (2) the median interval between breast reduction and cancer is 5 years; (3) the type, location, and side of breast cancers are similar in the two groups of women; (4) breast reduction does not significantly increase or decrease survival rate from breast cancer; and (5) women who have had breast reduction receive the same treatment for their breast cancer as women who have not had reduction mammaplasty.     

Breast reconstruction using tissue expanders and implants in Hodgkin's patients with prior mantle irradiation.

Women treated for Hodgkin's disease with mantle irradiation have an increased risk for developing breast cancer. Typically, breast malignancy in Hodgkin's patients presents bilaterally in a younger age group. Skin flap ischemia, poor skin expansion, implant extrusion, capsular contracture, and poor cosmesis are common sequelae of tissue expander/implant breast reconstruction after breast irradiation for failed breast conservation therapy. This has led most surgeons to favor autologous tissue reconstruction in this setting. This study was performed to determine the efficacy of tissue expander/implant breast reconstruction in breast cancer patients who have been treated with prior mantle irradiation for Hodgkin's disease. A retrospective analysis of all breast cancer patients with a history of Hodgkin's disease and mantle irradiation treated with mastectomy and tissue expander/implant reconstruction between 1992 and 1999 was performed. There were seven patients, with a mean age of 35 years (range, 28 to 42 years). The average interval between mantle irradiation and breast cancer diagnosis was 16 years (range, 12 to 23 years). All patients underwent two-stage reconstruction. Textured surface tissue expanders were placed in a complete submuscular position at the time of mastectomy. Expansion was initiated 2 weeks after insertion and continued on a weekly basis until completion. Expanders were replaced with textured surface saline-filled implants as a second stage. Patients were evaluated for skin flap ischemia, infection, quality of skin expansion, implant extrusion, capsular contracture, rippling, symmetry, and final aesthetic outcome. Breast cancer was bilateral in five patients and unilateral in two. Two patients did not undergo simultaneous bilateral breast reconstruction because of metachronous cancer development. One of the patients had an initial transverse rectus abdominis muscle flap breast reconstruction, followed by a tissue expander/implant reconstruction of the opposite breast. The average follow-up was 3 years. Complications were limited to one case of cellulitis after implant placement that resolved with intravenous antibiotics. There were no cases of skin flap ischemia, poor skin expansion, or implant extrusion. Overall patient satisfaction was high and revisions were not requested or required. Symmetry was best achieved with bilateral implants. This study demonstrates the efficacy of tissue expander/implant breast reconstruction in patients treated with prior mantle irradiation. In this series, tissue expansion was reliable with low morbidity. Second-stage placement of permanent implants yielded good aesthetic results without significant capsular contracture. Mantle irradiation did not appear to compromise the prosthetic breast reconstruction. Tissue expander/implant breast reconstruction should remain a viable option in this category of irradiated patients.     

State ranks of incident cancer burden due to overweight and obesity in the United States, 2003

Objective: Given links between obesity and cancer, we estimated incident cancer burden due to overweight and obesity at the state level in the United States. Methods and Procedures: Using state rankings by per capita burden of incident cancer cases diagnosed in 2003 that were related to overweight and obesity, we examined the frequency with which states ranked in the highest and lowest quintiles of weight‐related burden for cancers of the postmenopausal breast, endometrium, kidney, colon, and prostate. In this study, data from the Behavioral Risk Factor Surveillance System (BRFSS), US Census, US Mortality Public Use Data Tapes, and National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program were used. Results: Western states had the lowest weight‐related cancer burden for both sexes. Iowa, South Dakota, and West Virginia had the highest burden for all three types of male cancers. West Virginia is the only state that ranked in the quintile of highest weight‐related burden for all four cancers considered in women. Discussion: For certain cancers, including endometrial, postmenopausal breast, and colon cancers, states with high burdens clustered in geographic regions, warranting further inquiry. Although state ranks for the total cancer burden and the prevalence of overweight and obesity correlated with state ranks for weight‐related incident cancer burden, they often served poorly as its proxy. Such a finding cautions against simply targeting states with high overweight and obesity or high total burdens of cancers for which overweight and obesity are risk factors, as this approach may not reach areas of unrecognized burden.     

How breast cancer presents.

A study of 501 new breast cancers in patients seen in a consulting surgical practice revealed that 87% were in patients 45 years of age or older. The patients had found 83% of the cancers. The distributions of size and stage were the same for the tumours found by the patients and those found by the referring physicians. Two thirds of the cancers had an associated visible clinical sign, demonstrating the importance of inspection in the examination of the breast. Dimpling, sometimes apparent only on manipulation of the tumour, was present with 264 of the cancers and was often associated with "minimal" lesions. Mammography was done for 63 of the breast cancers but it missed 27. Of the physician-found cancers 15 were in patients who had already had breast cancer, 4 were in patients presenting with symptomatic metastases and 14 were in women presenting with other disorders. Of the 52 cancers found by periodic examination 3 were locally advanced and 21 had axillary metastases, while among the 28 "early" cancers 12 were in women who were senile, mentally defective or psychotic. Only four of the cancers found by the physicians were in women under age 45; two were rapidly fatal, one had an axillary metastasis, and the fourth was in a woman who had had cancer of the opposite breast. The remaining 284 lesions found by periodic or routine examination in women under age 45 were benign. Thus, periodic or routine examination for unsuspected breast cancer in women under age 45 seems unjustified except in those who have already had breast cancer.     

Postmastectomy breast reconstruction in Connecticut: trends and predictors.

Using the population-based Connecticut Tumor Registry, postmastectomy breast reconstruction was examined in the 10,756 breast cancers in Connecticut women (including 10,133 in white women and 554 in black women) diagnosed from 1988 to 1995. Reconstruction increased from 6.4 percent of cancers in 1988 to 9.1 percent in 1991, but it declined to 4.7 percent of cancers in 1992 (when the Food and Drug Administration instituted a restriction on the use of silicone gel implants); by 1995, the rate had recovered to 8.5 percent. Reconstruction was negatively associated with age, poverty rate of the census tract of residence, and black (versus white) race; these associations require further study.     

Reproductive events and family history as risk factors for breast cancer in northern Alberta.

Reproductive events and family history as risk factors for breast cancer in northern Alberta were investigated with the use of data from a computerized population-based registry. Women aged 30 to 79 years attending diagnostic breast clinics at the Cross Cancer Institute from 1971 through 1975 constituted the two study groups; 1232 women had diagnosed breast cancer (malignant disease group) and 602 women were clinically free of all types of breast disease (control group). An increased relative risk of breast cancer was found in women with a family history of breast cancer, those who gave birth to their first term infant at age 30 years or older, those in whom more than 15 years elapsed between menarche and that birth, and those with a late natural menopause. There was a decreased risk, relative to nulliparity, in the postmenopausal women who first gave birth to a term infant 5 years or less after menarche. Artificial menopause (bilateral oophorectomy), parity and age at menarche had no apparent effect on the risk. The pattern of risk factors in northern Alberta differed from that reported for other geographic areas, including other provinces of Canada, thus emphasizing the need for local studies in the planning of screening programs.     

Probabilities of dying from cancer and other causes in French cancer patients based on an unbiased estimator of net survival: A study of five common cancers

BackgroundNet survival is the survival that would be observed if cancer were the only possible cause of death. Although it is an important epidemiological tool allowing temporal or geographical comparisons, it cannot inform on the “crude” probability of death of cancer patients; i.e., when taking into account other possible causes of deaths.MethodsIn this work, we provide estimates of the crude probabilities of death from cancer and from other causes as well as the probability of being alive up to ten years after cancer diagnosis according to the age and year of diagnosis. Based on a flexible excess hazard model providing unbiased estimates of net survival, our methodology avoids the pitfalls associated with the use of the cause of death. We used data from FRANCIM, the French network of cancer registries, and studied five common cancer sites: head and neck, breast, prostate, lung, and colorectal cancers.ResultsFor breast, prostate, and colorectal cancers, the impact of the other causes on the total probability of death increased with the age at diagnosis whereas it remained negligible for lung and head and neck cancers whatever the age. For breast, prostate, and colorectal cancer, the more recently was the cancer diagnosed, the less was the probability of death from cancer.ConclusionThe crude probability of death is an intuitive concept that may prove particularly useful in choosing an appropriate treatment, or refining the indication of a screening strategy by allowing the clinician to estimate the proportion of cancer patients who will die specifically from cancer.     

Geographic disparities of breast cancer incidence in Portugal at the district level: A spatial age-period-cohort analysis, 1998-2011

BackgroundBreast cancer is the most common malignancy in women world-wide and the most common cause of cancer deaths, which can often be managed with early diagnosis and subsequent treatment. Here, we focus on geographic disparities in incidence within Portugal for three age groups of women (30−49; 50−69; 70−84 years).MethodsAge-period-cohort (APC) models are widely used in cancer surveillance, and these models have recently been extended to allow spatially-varying effects. We apply novel spatial APC models to estimate relative risk and age-adjusted temporal trends at the district level for the 20 districts in Portugal. Our model allows us to report on country-wide trends, but also to investigate geographic disparities between districts and trends within districts.ResultsAge-adjusted breast cancer incidence was increasing over 1998–2011 for all three age groups and in every district in Portugal. However, we detect spatially-structured between-district heterogeneity in relative risk and age-adjusted trends (Net Drifts) for each of the three age groups, which is most pronounced in the highly-screened (50−69yo) and late-onset (70−84yo) groups of women.ConclusionsWe present evidence of disparities in breast cancer incidence at a more granular geographic level than previously reported. Some disparities may be due to latent risk factors, which cannot be accounted for by age, birth year, and geographic location alone.ImpactOur study motivates resuming data collection for breast cancer incidence at the district level in Portugal, as well as the study of exogenous risk factors.