Incidence Of Breast Carcinoma Research Articles

Hypothyroidism enhances tumor invasiveness and metastasis development.

BackgroundWhereas there is increasing evidence that loss of expression and/or function of the thyroid hormone receptors (TRs) could result in a selective advantage for tumor development, the relationship between thyroid hormone levels and human cancer is a controversial issue. It has been reported that hypothyroidism might be a possible risk factor for liver and breast cancer in humans, but a lower incidence of breast carcinoma has been also reported in hypothyroid patientsMethodology/Principal FindingsIn this work we have analyzed the influence of hypothyroidism on tumor progression and metastasis development using xenografts of parental and TRβ1–expressing human hepatocarcinoma (SK-hep1) and breast cancer cells (MDA-MB-468). In agreement with our previous observations tumor invasiveness and metastasis formation was strongly repressed when TRβ–expressing cells were injected into euthyroid nude mice. Whereas tumor growth was retarded when cells were inoculated into hypothyroid hosts, tumors had a more mesenchymal phenotype, were more invasive and metastatic growth was enhanced. Increased aggressiveness and tumor growth retardation was also observed with parental cells that do not express TRs.Conclusions/SignificanceThese results show that changes in the stromal cells secondary to host hypothyroidism can modulate tumor progression and metastatic growth independently of the presence of TRs on the tumor cells. On the other hand, the finding that hypothyroidism can affect differentially tumor growth and invasiveness can contribute to the explanation of the confounding reports on the influence of thyroidal status in human cancer.

Primary small cell carcinoma of the lung initially presenting as a breast mass: A fine‐needle aspiration diagnosis

The incidence of metastases to the breast from extramammary sites is relatively low compared with the incidence of primary breast carcinoma. Primary sites which have a predilection for metastases to the breast include, in the order of decreasing frequency, malignant melanoma, lymphoma, lung carcinoma, ovarian carcinoma, and soft tissue sarcoma, followed by gastrointestinal and genitourinary primaries. Most lung primaries metastasizing to breast represent adenocarcinoma. Other types of lung carcinoma, including small cell carcinoma, are relatively rare. We report a case of lung small cell carcinoma metastasizing to the breast and initially presenting with a breast mass in a 50-year-old female. The tumor was first diagnosed on a fine-needle aspiration biopsy specimen (FNAB) from the breast lesion and subsequently supported by core biopsy. A discussion of the differential diagnoses to consider on FNAB follows. Because of the difference in treatment for primary small cell carcinoma of breast versus primary small cell carcinoma of the lung, as well as the difference in prognosis for both malignancies, determining the site of primary malignancy is crucial to adequate patient care.

Collision Metastasis of Breast and Ovarian Adenocarcinoma in Axillary Lymph Nodes: A Case Report and Review of the Literature

Despite their accepted clinical and genetic association, the incidence of synchronous breast and ovarian carcinoma is rare. Moreover, collision metastasis from both breast and ovarian carcinomas to the same lymph node, to our knowledge has never been reported. Review of the literature revealed eleven cases of metastatic malignant tumors colliding in the same lymph node, none of which had both ovarian and breast carcinoma. Our case was that of a 63 year old woman presenting with a breast lump that was diagnosed as infiltrating ductal carcinoma after a needle biopsy. One month later the patient was found to have malignant ascites, omental carcinomatosis and an ovarian mass. Histology and immunohistochemistry revealed high grade serous papillary adenocarcinoma. When surgery was done to treat the breast tumor some of the axillary lymph nodes revealed metastases from the breast primary, others metastases from the ovarian primary and one had both tumors in a collision phenomenon. Immunohistochemistry was used to confirm this finding.

Carcinoma de mama durante el embarazo

Pregnancy associated breast cancer includes cancers concurrent with pregnancy and those diagnosed up to 1 year after delivery. The incidence of breast carcinoma in pregnancy is estimated to be approximately 1 in 3000 pregnancies. Due to the difficulties of clinical breast examination, diagnosis is frequently delayed and made when the cancer stage has progressed. Consequently, prognosis is usually poor. Treatment options are limited by concern about harming the fetus and depend on gestational age. We present the case of a 34-year-old woman who was diagnosed with cancer of the right breast in the 28th week of gestation. The patient underwent modified radical mastectomy. This association is uncommon but is not exceptional. Knowledge of cases such as that reported herein will allow early diagnosis and improve the prognosis of these patients.

Das männliche Mammakarzinom - Erfahrungen eines Zentrums

Male breast carcinoma represents a rare tumor entity and is not the focus of major research activities although an increasing incidence has to be noticed. Registry data on 67 males diagnosed and treated for breast carcinoma during the period 1985-2005 in the metropolitan area of Leipzig were retrospectively analyzed. The median age at diagnosis was 65 years (39-92 years) with an incidence peak in the age group 60-70 years. According to the TNM classification a carcinoma in situ was diagnosed in 8 % (n = 5) of the cases and an invasive carcinoma T1 in 39 % (n = 26 ), T2 in 38 % (n = 25), T3 (n = 0) and T4 in 15 % (n = 11). The lymphnode status presented in 56 % negative and in 44 % positive (N1 + N2) nodes. Solid organ metastasis was detected in only 6 % of the patients. The overall 5-year survival is 72 % and comparable with published data. Respective survival rates for patients diagnosed with UICC-stadium 1-4 are 81 %, 76 %, 65 % and 0 %. These rates are similar to those of female patients. Considering the low incidence of male breast carcinoma and the limited knowledge on this rare disease surgeons should apply diagnostic and therapeutic guidelines that are established for the treatment of female breast carcinoma unless powerful evidence based data will become available.

The Theory of the Sick Breast Lobe and the Possible Consequences

We hypothesize that carcinoma in situ, and consequently breast carcinoma in general, is a lobar disease because the simultaneously or asynchronously appearing, often multiple tumor foci develop within a single lobe. The sick lobe carries some kind of genetic instability already from its initialization during the early embryonic life and is more sensitive to noxious influences than the other lobes within the same breast. Decades of postnatal life with accumulation of additional genetic alterations are needed for malignant transformation of the cells within the sick lobe. The transformation is often multifocal (involving separate distant lobules of this lobe) or diffuse (involving the larger ducts). This hypothesis offers new perspectives in cancer prevention, because selective visualization, excision, or destruction of the sick lobe before development of malignant lesions would substantially reduce the incidence of breast carcinoma.

Modern concepts of ductal carcinoma in situ (DCIS) and its diagnosis through percutaneous biopsy

The incidence of ductal breast carcinoma in situ (DCIS) is increasing and currently lies at about 15% of all breast cancers. Detection of DCIS reduces the subsequent incidence of invasive ductal carcinoma. Patients with Breast Imaging Reporting and Data System (BI-RADS) category 4 lesions are best served by minimally invasive biopsies to improve the precision of diagnosing DCIS lesions. Vacuum-assisted biopsies have the greatest sensitivity and specificity of the biopsy techniques and reduce tumor upgrading of DCIS lesions at operation by at least half compared with core-needle biopsy. Moreover, vacuum-assisted biopsies have proved to be safe and reduce health care costs. Since they provide a maximum of preoperative information, vacuum-assisted biopsies could improve outcomes in patients with DCIS.

Extensive Cutaneous Metastatic Breast Carcinoma of the Hand and Upper Extremity: A Case Report

Cutaneous metastatic breast carcinoma involving the hand is extremely rare. We report a case of a 39-year-old woman with a history of recurrent invasive ductal adenocarcinoma of the breast who had a right modified radical mastectomy, chemotherapy, and radiation therapy before presenting to our institution with extensive cutaneous metastasis to the upper limb including the hand. The presentation, pathogenesis, incidence, prognosis, management, and differential diagnosis of cutaneous metastatic breast carcinoma to the hand and upper limb are discussed.

BARRIERS TO ACCRUAL TO CLINICAL TRIALS FOR BREAST CARCINOMA IN MINORITY WOMEN IN EASTERN NORTH CAROLINA.

Purpose Despite national statistics that indicate a lower incidence of breast carcinoma among African American women than Caucasian women, the mortality rate for African American women is higher. Data regarding these differences in mortality and incidence can only be obtained through inclusion of women of ethnic groups on large national clinical trials. Presently, fewer minorities enrol in clinical trials than Caucasian women. Some barriers to minority participation in clinical trials are common to all areas of the United States, whereas some factors are unique to specific geographic areas. This study was designed to determine what specific factors, such as illiteracy, impact minority enrolment onto clinical trials in rural eastern North Carolina. Methods All newly diagnosed breast cancer patients at our center were asked to participate in a pilot questionnaire study from August to October 2006. Information requested included distance to travel for therapy, education, income, and prior knowledge of cancer or clinical trials. Results Education levels, income levels, regular health care evaluations, and insurance coverage differed between the minority and nonminority participants. Religious affiliation did not differ between these groups. Eighty-three percent of Caucasian women recorded knowing what a clinical trial was and could provide a correct description of a clinical study; 30% of minority women knew the accurate definition of a clinical trial. No minority patients reported knowing someone who had participated in a clinical trial, whereas 17% of Caucasian women did. Forty percent of minority participants knew individuals who had been treated for cancer versus 50% of Caucasians. Sixty-seven percent of Caucasian women would participate in a clinical trial; 40% of minority women reported that they would participate. Conclusions There is a discrepancy between the economic and education levels of our minority and nonminority breast cancer patients in eastern North Carolina. This corresponds with uninsured patients and women who do not have the ability to obtain regular medical care. Additionally, personal experience with cancer treatments is different between the groups. A larger study is needed to gather more information on how to further define efforts for accrual to clinical trials.

Service screening mammography reduces breast cancer mortality among elderly women in Turku

The aim of this study was to assess the effects of service screening mammography on breast carcinoma incidence and refined mortality among women aged 55-69 at entry in three cities employing different screening policies. Since 1987, the city of Turku, Finland, has provided service screening mammography for women aged 55-69 at entry (in 1987), and Tampere provided screening for women aged 55-59 at entry, whereas Helsinki did not screen any of these age groups. The incidence of breast carcinoma during the screening period 1987-97 in women born in 1918-32 (1918-22, 1923-27, 1928-32) was compared with incidence during the pre-screening period 1976-86 in women born in 1907-21 (1907-11, 1912-16, 1917-21) in each city. The follow-up for mortality was four years longer. Breast carcinoma incidence was 31-38% higher in the screening period in all three cities irrespective of screening. In breast carcinoma mortality, no significant changes were seen in Helsinki or Tampere. In Turku, a 36% mortality reduction (relative risk [RR] 0.64; 95% confidence interval [CI] 0.47-0.88; P=0.007) in the whole study population and a 47% reduction in women aged 65-69 at entry (RR 0.53; 95% CI 0.28-0.99; P=0.047) were seen. The incidence of breast carcinoma increased in all study cities irrespective of screening. The comprehensive screening programme in Turku including women aged 55-69 at entry was associated with a significant reduction in breast carcinoma mortality. The pronounced decrease in mortality in the oldest age group (65-69 years at entry) also indicated that women of this age group greatly benefit from mammography screening.

Trends in Inflammatory Breast Carcinoma Incidence and Survival: The Surveillance, Epidemiology, and End Results Program at the National Cancer Institute

Trends in Inflammatory Breast Carcinoma Incidence and Survival: The Surveillance, Epidemiology, and End Results Program at the National Cancer Institute

Inter- and intra-ethnic differences for female breast carcinoma incidence in the continental United States and in the state of Hawaii

Ethnic diversity is well-documented for female breast carcinoma incidence in the continental US but is not so well-established in the state of Hawaii. Using the Surveillance, Epidemiology, and End Results (SEER) program, we analyzed n=323,607 in situ and invasive female breast cancer cases for major ethnic groups in the continental US and in Hawaii, diagnosed during the years 1992-2002. In the continental US, age-specific incidence rate patterns and prognostic factor profiles were good-risk for Asian or Pacific Islanders (API), intermediate for Whites, and poor-risk for Blacks. For example, early age-at-onset, high nuclear grade, aggressive histopathologic subtypes, and hormone receptor negative expression was associated with Black race in the continental US. In Hawaii, age-specific rate and prognostic profiles were more favorable for API than for White women, albeit not so striking as in the continental US. We observed inter- and intra-ethnic differences for female breast carcinoma in the continental US and in the state of Hawaii. While inter-racial disparities were expected, intra-racial differences were somewhat unexpected and possibly due to variations in racial subgroup mixing and/or cultural assimilation. For example, API women with breast carcinoma in the continental US included 96.03% Asians and 2.4% Pacific Islanders. In contrast, API women with breast carcinoma in Hawaii included 76.52% Asians and 23.46% Pacific Islanders. Moreover, APIs were more likely to be first-generation migrants in the continental US ( approximately 92%) than in Hawaii ( approximately 34%). Future studies should attempt to disaggregate racial data to separately characterize epidemiological patterns for individual ethnic groups.

In situ male breast carcinoma in the Surveillance, Epidemiology, and End Results database of the National Cancer Institute

In situ breast carcinoma is not so well characterized for men as for women. Therefore, the authors of the current study compared male and female in situ and invasive breast carcinomas in the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute to document these patterns. In situ breast carcinomas composed 9.4% of all male (n = 280 of 2984) and 11.9% of all female breast carcinomas (n = 53,928 of 454,405) during the years 1973-2001. In situ rates rose 123% for men and 555% for women over this time period; whereas distant disease rates fell for both genders. Median ages at diagnosis were 62 years for in situ and 68 years for invasive breast carcinoma among men, compared with 58 years for in situ and 62 years for invasive breast carcinoma among women. Papillary in situ and invasive architectural types were more common among men than women. In contrast, lobular tumors were more common among women than men. Breast cancer-specific survival was similar among men and women, whereas overall survival was worse for men than women. In situ male breast carcinoma is a rare disease, occurring at older ages and with different architectural types than its more common female counterpart. Gender-specific histopathologic differences probably reflect anatomic differences among the normal female and vestigial male breast. Rising in situ male breast carcinoma incidence rates over the past three decades suggest earlier detection over time, irrespective of mammography, because men do not participate in routine screening mammography. Worse overall survival for men than women possibly results from age-dependent comorbid illnesses.

The red wine phenolics piceatannol and myricetin act as agonists for estrogen receptor α in human breast cancer cells

Previous epidemiological reports have suggested that red wine intake is associated with beneficial health effects due to the ability of certain phytochemical components to exert estrogen-like activity. It has been also documented that estrogens induce the proliferation of hormone-dependent breast cancer cells by binding to and transactivating estrogen receptor (ER) alpha, which in turn interacts with responsive DNA sequences located within the promoter region of target genes. In order to provide further insight into the positive association between wine consumption and the incidence of breast carcinoma in postmenopausal women, we have evaluated the estrogenic properties of two abundant wine-derived compounds, named piceatannol (PIC) and myricetin (MYR), using as model systems the hormone-sensitive MCF7 and the endocrine-independent SKBR3 breast cancer cells. On the basis of our experimental evidence PIC and MYR may contribute to the estrogenicity of red wine since: (1) they transactivate endogenous ER alpha; (2) they activate the agonist-dependent activation function (AF) 2 of ER alpha and ER beta in the context of the Gal4 chimeric proteins; (3) they rapidly induce the nuclear immunodetection of ER alpha; (4) they regulate the expression of diverse estrogen target genes; (5) they compete with 17beta-estradiol for binding to ER alpha and ER beta; and--as a biological counterpart of the aforementioned abilities--(6) they exert stimulatory effects on the proliferation of MCF7 cells. Hence, the estrogenic activity of PIC and MYR might be considered at least as a potential factor in the association of red wine intake and breast tumors, particularly in postmenopausal women.

Trends in inflammatory breast carcinoma incidence and survival: the surveillance, epidemiology, and end results program at the National Cancer Institute.

Inflammatory breast carcinoma (IBC) appears to be a clinicopathologic entity distinct from noninflammatory locally advanced breast cancer (LABC). We examined incidence and survival trends for IBC in Surveillance, Epidemiology, and End Results (SEER) Program data with a case definition designed to capture many of its unique clinical and pathologic characteristics. We analyzed breast cancer cases diagnosed in the SEER 9 Registries (n = 180,224), between 1988 and 2000. Breast cancer cases were categorized using SEER's "Extent of Disease" codes in combination with International Classification of Diseases for Oncology morphology code 8530/3 and classified as IBC (n = 3648), LABC (n = 3636), and non-T4 breast cancer (n = 172,940). We compared changes in incidence rates over 3-year intervals by breast cancer subtype and race using SEER*Stat. Survival differences by breast cancer subtype and race were assessed using Kaplan-Meier curves and log-rank statistics. All statistical tests were two-sided. Between 1988 and 1990 and 1997 and 1999, IBC incidence rates (per 100,000 woman-years) increased from 2.0 to 2.5 (P < .001), whereas those for LABC declined (2.5 to 2.0, P = .0025), as did those for non-T4 breast cancer (108 to 101, P = .0084). IBC incidence rates were statistically significantly higher in black women (3.1) than in white women (2.2) during the study period (P < .001). Women diagnosed with IBC had statistically significantly poorer survival than women with either LABC or non-T4 breast cancer (log-rank test, P < .001). Median survival of women with IBC (2.9 years) was statistically significantly shorter than that of women with LABC (6.4 years; P < .0001) or non-T4 breast cancer (> 10 years, P < .0001). Black women with IBC or LABC had poorer survival than white women with IBC or LABC, respectively (log-rank test, P < .001). Throughout the 1990s, IBC incidence rose, and survival improved modestly. Substantial racial differences were noted in age at diagnosis, age-specific incidence rates, and survival outcomes.

Neighborhood composition and incidence of cancer among Hispanics in the United States

Hispanics in the United States have a 33% lower age-adjusted incidence of cancer and a 38% lower cancer mortality rate compared with non-Hispanic whites. This may be secondary to health behaviors that vary with residential and economic assimilation. The authors investigated whether cancer incidence among Hispanics increased with residential and economic assimilation into mainstream culture. Data from the Surveillance, Epidemiology, and End Results program (SEER) and the U.S. Census Bureau were used to compare cancer incidence rates and rate ratios as a function of percentage of Hispanics and income of Hispanics in a census tract. Type of cancer was identified with a site recode variable in the SEER data set. Cases with in situ prostate and cervical carcinoma were excluded. Hispanic ethnicity in SEER was identified by medical record review and Hispanic surname lists. The study also used income of Hispanics living in the census tract, age at diagnosis, and stratification by gender. The incidence of breast, colorectal, and lung carcinoma among Hispanics increased as the percentage of Hispanics in the census tract decreased and as tract Hispanic income increased. For example, there was a 39% reduction in breast carcinoma and a 38% reduction in male colorectal carcinoma when the Hispanic population in high-density Hispanic neighborhoods in the lowest income quartile was contrasted to Hispanics living in tracts with the lowest total percentage of Hispanics in the highest income quartile. The lower cancer rates among Hispanics relative to non-Hispanic whites in the United States may dissipate as Hispanics become more assimilated into the mainstream society.

Short‐term, medium‐term, long‐term, and lifetime risks of developing and dying of breast carcinoma in a Westernized Chinese population

Estimates of lifetime and shorter-term risks of developing and dying of breast carcinoma are useful translational statistics for risk communication; however, these statistics are unknown for Chinese women, who account for one-fifth of the world's female population. In the current study, the authors examined age-specific 5-year, 10-year, 20-year, and lifetime risks of breast carcinoma incidence and disease-related mortality among Hong Kong women. Multiple-decrement life tables were constructed by applying age-specific incidence and mortality rates obtained from cross-sectional data to a hypothetic birth cohort. Incidence, mortality, and population data from 1976 through 2000 were used. For Hong Kong women in the period 1996-2000, the overall lifetime risk of developing invasive breast carcinoma was 5.7% (1 in 17), compared with 10.6% (1 in 9) for U.S. Asian/Pacific Islander women and 14.5% (1 in 7) for U.S. white women. The lifetime breast carcinoma-related mortality risk for Hong Kong women in that same period was 1.7% (1 in 58). For women age 50 years, the 5-, 10-, and 20-year risks of developing breast carcinoma were 0.6% (1 in 172), 1.1% (1 in 87), and 2.1% (1 in 47), respectively. The absolute lifetime probability of developing breast carcinoma increased from 3.81% (1 in 26) during the period 1976-1980 to 5.73% (1 in 17) during the period 1996-2000; 44.5% of this change can be attributed to the increased longevity of women in the latter time period, and the remaining 55.5% can be ascribed to a secular rise in breast carcinoma incidence. As China becomes more Westernized, the authors expect that the risks of developing and dying of breast carcinoma for Chinese women will become more similar to the corresponding risks for Western women. The current data from Hong Kong, the most Westernized Chinese community, appear to support this conclusion.

Lobular neoplasia on core-needle biopsy--clinical significance.

Approximately 25% of all cases of atypical ductal hyperplasia (ADH) diagnosed on core biopsy of the breast are associated with ductal carcinoma in situ (DCIS) or invasive malignancy at the same site. As a result, surgical excision has become the standard of care for patients with ADH. In contrast, because data on the relation between breast malignancy and lobular neoplasia (LN) detected on core biopsy are limited, clinical management of patients with LN remains controversial. The goal of the current study was to determine the incidence of breast carcinoma at sites of core biopsy exhibiting LN compared with sites of core biopsy exhibiting ADH. The results of 2053 core biopsies were reviewed to identify cases of LN and cases of ADH. Follow-up findings on excisional biopsy were categorized as malignancy (DCIS or invasive malignancy) or no malignancy and were compared between the LN group and the ADH group. Mammograms and medical records were reviewed for patients with atypical findings on core biopsy. One hundred six (5.2%) of 2053 biopsy samples exhibited atypia on core biopsy. Among these 106 samples, ADH was found in 49 (46%), LN was found in 45 (42%), and both ADH and LN were found in 12 (12%). Malignant disease was detected on follow-up excisional biopsy in 22% of patients with ADH (9 of 41), 14% of patients with LN (3 of 21), and 33% of patients with both ADH and LN (4 of 12) on core biopsy. In the LN group, two cases of malignant disease were associated with lobular carcinoma in situ, and the third case was associated with atypical lobular hyperplasia. Mammographic and clinical features were unable to distinguish patients with malignant findings on excisional biopsy from patients without malignant findings. Malignant disease was found in a substantial percentage of excisional biopsy samples (14%) following the detection of LN on core biopsy. Thus, like patients with ADH, patients with LN on core biopsy could be considered candidates for surgical excision, which would allow full assessment of breast carcinoma risk and thereby facilitate the planning of prevention strategies.

Hormone replacement therapy in relation to breast carcinoma incidence rate ratios: a prospective Danish cohort study.

The goal of the current study was to investigate the relation between hormone replacement therapy (HRT) and breast carcinoma in a prospective study cohort. Particular attention was paid to the type of HRT used and to the association of HRT type with estrogen receptor status and tumor histology. Between 1993 and 1997, a total of 29,875 women were enrolled in the Danish Cancer Society's prospective "Diet, Cancer and Health" study. Among 23,618 women who were assumed to be postmenopausal and for whom information on HRT use was available, we identified 423 cases of breast carcinoma over a median follow-up period of 4.8 years. Statistical analyses were based on the Cox proportional hazards model, with age serving as the time parameter. The breast carcinoma incidence rate ratio (IRR) was 2.22 (95% confidence interval [CI], 1.80-2.75) for users of HRT at baseline compared with women who never received HRT. Among HRT users (relative to nonusers), the IRR for estrogen receptor-positive tumors (2.38; 95% CI, 1.84-3.06) was greater than the IRR for estrogen receptor-negative tumors (1.56; 95% CI, 1.00-2.43). HRT use at baseline also was analyzed in relation to the incidence of lobular carcinoma and the incidence of ductal carcinoma; the adjusted IRR associated with HRT use was 3.53 (95% CI, 1.94-6.41) for lobular carcinoma and 2.10 (95% CI, 1.64-2.70) for ductal carcinoma. The likelihood of developing estrogen receptor-positive breast carcinoma was found to depend significantly on the type of HRT regimen used (P = 0.03), with women receiving continuous therapy having the greatest probability of developing estrogen receptor-positive disease. An increased breast carcinoma IRR was found to be associated with current HRT use. In addition, relative to other types of HRT regimens, continuous estrogen + progestin regimens were found to be associated with an increased risk of breast carcinoma, and particularly estrogen receptor-positive breast carcinoma.

Can the Gail model be useful in American Indian and Alaska Native populations?

Very little is known about breast carcinoma risk factors for American Indian/Alaska Native (AI/AN) women undergoing screening. The Gail model has been a useful tool for predicting the risk of breast carcinoma in several populations. It has not been applied systematically to AI/AN women. The current study was a retrospective review of 1458 screening mammograms performed for AI/AN women. The authors applied the Gail model to estimate both absolute risk and relative risk for breast carcinoma for AI/AN women screened in South Dakota, Arizona, and Alaska. The mean age of the women was 52.4 years. The onset of menses was not significantly different than expected. The average age at first birth was 20 years, very few women were nulliparous, and few women were age > 30 years at first live birth. The proportion of women reporting a first- or second-degree relative with breast carcinoma was similar to the proportion in the general population. The results of the model indicated an overall average relative risk that ranged from 1.42 to 2.69 compared with white American women, depending on the model assumptions used. Using a modified Gail model and calculating an imputed absolute risk, the expected incidence of breast carcinoma in this population increased to rates of 170-180 per 100,000 in the next 10 years, a significant increase over the Surveillance, Epidemiology and End Results-derived incidence rates from 1988 to 1992 of 31.6 per 100,000 for AI women in New Mexico and 78.9 per 100,000 for AN women. The model indicated a likelihood of increasing rates of breast carcinoma in the study population. The data obtained were useful in generating preliminary estimates of breast carcinoma risk in the study population, for which no prospective population survey has been completed. The inherent weaknesses in the current retrospective study indicated the need for a large-scale prospective data collection to confirm these exploratory findings.