Preventing invasive breast cancer using endocrine therapy

Developments in breast cancer treatment have resulted in reduction in breast cancer mortality in the developed world. However incidence continues to rise and greater use of preventive interventions including the use of therapeutic agents is needed to control this burden. High quality evidence from 9 major trials involving more than 83000 participants shows that selective oestrogen receptor modulators (SERMs) reduce breast cancer incidence by 38%. Combined results from 2 large trials with 8424 participants show that aromatase inhibitors (AIs) reduce breast cancer incidence by 53%. These benefits are restricted to prevention of ER positive breast cancers. Restricting preventive therapy to high-risk women improves the benefit-harm balance and many guidelines now encourage healthcare professionals to discuss preventive therapy in these women. Further research is needed to improve our risk-prediction models for the identification of high risk women for preventive therapy with greater accuracy and to develop surrogate biomarkers of response. Long-term follow-up of the IBIS-I trial has provided valuable insights into the durability of benefits from preventive therapy, and underscores the need for such follow up to fully evaluate other agents. Full utilisation of preventive therapy also requires greater knowledge and awareness among both doctors and patients about benefits, harms and risk factors. Healthcare professionals should routinely discuss preventive therapy with women at high-risk of breast cancer.

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.

Anastrozole versus tamoxifen for the prevention of locoregional and contralateral breast cancer in postmenopausal women with locally excised ductal carcinoma in situ (IBIS-II DCIS): a double-blind, randomised controlled trial

BACKGROUND

Third-generation aromatase inhibitors are more effective than tamoxifen for preventing recurrence in postmenopausal women with hormone-receptor-positive invasive breast cancer. However, it is not known whether anastrozole is more effective than tamoxifen for women with hormone-receptor-positive ductal carcinoma in situ (DCIS). Here, we compare the efficacy of anastrozole with that of tamoxifen in postmenopausal women with hormone-receptor-positive DCIS.

METHODS

In a double-blind, multicentre, randomised placebo-controlled trial, we recruited women who had been diagnosed with locally excised, hormone-receptor-positive DCIS. Eligible women were randomly assigned in a 1:1 ratio by central computer allocation to receive 1 mg oral anastrozole or 20 mg oral tamoxifen every day for 5 years. Randomisation was stratified by major centre or hub and was done in blocks (six, eight, or ten). All trial personnel, participants, and clinicians were masked to treatment allocation and only the trial statistician had access to treatment allocation. The primary endpoint was all recurrence, including recurrent DCIS and new contralateral tumours. All analyses were done on a modified intention-to-treat basis (in all women who were randomised and did not revoke consent for their data to be included) and proportional hazard models were used to compute hazard ratios and corresponding confidence intervals. This trial is registered at the ISRCTN registry, number ISRCTN37546358.

RESULTS

Between March 3, 2003, and Feb 8, 2012, we enrolled 2980 postmenopausal women from 236 centres in 14 countries and randomly assigned them to receive anastrozole (1449 analysed) or tamoxifen (1489 analysed). Median follow-up was 7·2 years (IQR 5·6-8·9), and 144 breast cancer recurrences were recorded. We noted no statistically significant difference in overall recurrence (67 recurrences for anastrozole vs 77 for tamoxifen; HR 0·89 [95% CI 0·64-1·23]). The non-inferiority of anastrozole was established (upper 95% CI <1·25), but its superiority to tamoxifen was not (p=0·49). A total of 69 deaths were recorded (33 for anastrozole vs 36 for tamoxifen; HR 0·93 [95% CI 0·58-1·50], p=0·78), and no specific cause was more common in one group than the other. The number of women reporting any adverse event was similar between anastrozole (1323 women, 91%) and tamoxifen (1379 women, 93%); the side-effect profiles of the two drugs differed, with more fractures, musculoskeletal events, hypercholesterolaemia, and strokes with anastrozole and more muscle spasm, gynaecological cancers and symptoms, vasomotor symptoms, and deep vein thromboses with tamoxifen.

CONCLUSIONS

No clear efficacy differences were seen between the two treatments. Anastrozole offers another treatment option for postmenopausal women with hormone-receptor-positive DCIS, which may be be more appropriate for some women with contraindications for tamoxifen. Longer follow-up will be necessary to fully evaluate treatment differences.

FUNDING

Cancer Research UK, National Health and Medical Research Council Australia, Breast Cancer Research Fund, AstraZeneca, Sanofi Aventis.

Variation in Breast Cancer-Risk Factor Associations by Method of Detection: Results From a Series of Case-Control Studies

Concerns about breast cancer overdiagnosis have increased the need to understand how cancers detected through screening mammography differ from those first detected by a woman or her clinician. We investigated risk factor associations for invasive breast cancer by method of detection within a series of case-control studies (1992-2007) carried out in Wisconsin, Massachusetts, and New Hampshire (n=15,648 invasive breast cancer patients and 17,602 controls aged 40-79 years). Approximately half of case women reported that their cancer had been detected by mammographic screening and half that they or their clinician had detected it. In polytomous logistic regression models, parity and age at first birth were more strongly associated with risk of mammography-detected breast cancer than with risk of woman/clinician-detected breast cancer (P≤0.01; adjusted for mammography utilization). Among postmenopausal women, estrogen-progestin hormone use was predominantly associated with risk of woman/clinician-detected breast cancer (odds ratio (OR)=1.49, 95% confidence interval (CI): 1.29, 1.72), whereas obesity was predominantly associated with risk of mammography-detected breast cancer (OR=1.72, 95% CI: 1.54, 1.92). Among regularly screened premenopausal women, obesity was not associated with increased risk of mammography-detected breast cancer (OR=0.99, 95% CI: 0.83, 1.18), but it was associated with reduced risk of woman/clinician-detected breast cancer (OR=0.53, 95% CI: 0.43, 0.64). These findings indicate important differences in breast cancer risk factors according to method of detection.

Predictors for contralateral prophylactic mastectomy in breast cancer patients

BACKGROUND

In recent years, radical breast cancer surgery has been largely replaced by breast conservation treatment, due to early diagnosis and more effective adjuvant treatment. While breast conservation is mostly preferred, the trend of bilateral mastectomy has risen in the United States. The aim of this study is to determine factors influencing patients' choice for having contralateral prophylactic mastectomy (CPM).

METHODS

This is a retrospective study of 373 patients diagnosed with primary invasive breast cancer who were treated by bilateral or unilateral mastectomy (BM or UM) at the Revlon/UCLA Breast Center between Jan. 2002 and Dec. 2010. In the BM group, only those with unilateral breast cancer who chose CPM were included in the analysis.

RESULTS

When compared with the UM group, the following factors were found to be associated with BM: younger age, pre-menopausal, a family history of breast/ovarian cancer, BRCA mutation, more breast biopsies, history of breast augmentation, having MRI study within 6 months before the surgery, more likely to have reconstruction and sentinel lymph node biopsy (SLNB) and fewer had neoadjuvant/adjuvant chemotherapy/radiation. When patients with bilateral breast cancer were excluded, multivariate logistic regression analysis indicated younger patients with negative nodes, SLNB as the only nodal surgery and positive family history were significant factors predicting CPM and immediate reconstruction using tissue expanders or implants.

CONCLUSION

Younger age, lower TN stage, requiring only SLNB and high risk family history predict contralateral prophylactic mastectomy. Tissue expander/implant-based reconstructions were more frequently chosen by patients with BM.

Anastrozole for prevention of breast cancer in high-risk postmenopausal women (IBIS-II): an international, double-blind, randomised placebo-controlled trial

BACKGROUND

Aromatase inhibitors effectively prevent breast cancer recurrence and development of new contralateral tumours in postmenopausal women. We assessed the efficacy and safety of the aromatase inhibitor anastrozole for prevention of breast cancer in postmenopausal women who are at high risk of the disease.

METHODS

Between Feb 2, 2003, and Jan 31, 2012, we recruited postmenopausal women aged 40-70 years from 18 countries into an international, double-blind, randomised placebo-controlled trial. To be eligible, women had to be at increased risk of breast cancer (judged on the basis of specific criteria). Eligible women were randomly assigned (1:1) by central computer allocation to receive 1 mg oral anastrozole or matching placebo every day for 5 years. Randomisation was stratified by country and was done with blocks (size six, eight, or ten). All trial personnel, participants, and clinicians were masked to treatment allocation; only the trial statistician was unmasked. The primary endpoint was histologically confirmed breast cancer (invasive cancers or non-invasive ductal carcinoma in situ). Analyses were done by intention to treat. This trial is registered, number ISRCTN31488319.

FINDINGS

1920 women were randomly assigned to receive anastrozole and 1944 to placebo. After a median follow-up of 5·0 years (IQR 3·0-7·1), 40 women in the anastrozole group (2%) and 85 in the placebo group (4%) had developed breast cancer (hazard ratio 0·47, 95% CI 0·32-0·68, p<0·0001). The predicted cumulative incidence of all breast cancers after 7 years was 5·6% in the placebo group and 2·8% in the anastrozole group. 18 deaths were reported in the anastrozole group and 17 in the placebo group, and no specific causes were more common in one group than the other (p=0·836).

INTERPRETATION

Anastrozole effectively reduces incidence of breast cancer in high-risk postmenopausal women. This finding, along with the fact that most of the side-effects associated with oestrogen deprivation were not attributable to treatment, provides support for the use of anastrozole in postmenopausal women at high risk of breast cancer.

FUNDING

Cancer Research UK, the National Health and Medical Research Council Australia, Sanofi-Aventis, and AstraZeneca.

Prophylactic mastectomy: is it worth it?

BACKGROUND

Breast cancer is the second mortality-related cancer and the leading cause of general mortality in women aged 40-55. Prophylactic mastectomy has proved to be effective in several clinical scenarios but is still a somewhat controversial procedure.

METHODS

We performed a retrospective study by reviewing the records of all patients who underwent prophylactic mastectomy in a 25-year period. We evaluated the aesthetic and long-term oncologic outcomes, complications, and patient satisfaction.

RESULTS

We had 52 patients, 40 of them unilateral cases (contralateral prophylactic mastectomy) and 12 bilateral (bilateral prophylactic mastectomy) for a total of 64 mastectomized breasts. We had 1 (1.56%) case of unexpected breast cancer in the mastectomy specimens. Forty-two (65.62%) cases had a subcutaneous prophylactic mastectomy and 22 (34.37%) cases had a simple total prophylactic mastectomy. Fifty-eight (90.62%) cases underwent reconstruction with alloplastics and 6 (9.37) cases with autologous tissue of which 5 (7.81%) cases received latissimus dorsi flaps with alloplastic implants and 1 (1.56%) case had a TRAM flap. The complications included 4 (6.25%) breasts that developed capsular contracture, 2 (3.12%) cases of hematoma, and 1 (1.56%) infection. Concerning patient satisfaction, 39 (75%) patients reported being highly satisfied, 10 (19.23%) partially satisfied, and 3 (5.76%) unsatisfied. When we performed the aesthetic evaluation according to our scale, we got an overall aesthetic index of 8.8.

CONCLUSION

Prophylactic mastectomy is becoming an increasingly frequent procedure. Plastic surgeons should consider the aesthetic outcome when planning mastectomy and reconstruction. Our ability to predict the high-risk population has improved and it is that population who can get the best benefit from this intervention. The recommendation against subcutaneous prophylactic mastectomy lacks scientific evidence. There is plenty of evidence that prophylactic mastectomy lowers the risk of breast cancer in the high-risk population in at least 95%. Our experience with prophylactic mastectomy is extremely satisfactory, with an overall patient satisfaction rate of 94%, no mortality, and an oncologic long-term outcome of 0% of ulterior development of breast cancer. Our series, although relatively small, should provide some insight into the power of this technique and we think all plastic surgeons should have it in their surgical armamentarium and should share their experiences so that this procedure may become more widely accepted. We also think that plastic surgeons should strive for perfecting the technique to reduce the complication rate and therefore help the procedure gain acceptance by the medical community.

Comparing the benefits of screening for breast cancer and lung cancer using a novel natural history model

To estimate the impact of early detection of cancer, knowledge of how quickly primary tumors grow and at what size they shed lethal metastases is critical. We developed a natural history model of cancer to estimate the probability of disease-specific cure as a function of tumor size, the tumor volume doubling time (TVDT), and disease-specific mortality reduction achievable by screening. The model was applied to non-small-cell lung carcinoma (NSCLC) and invasive ductal carcinoma (IDC), separately. Model parameter estimates were based on Surveillance Epidemiology and End Results (SEER) cancer registry datasets and validated on screening trials. Compared to IDC, NSCLC is estimated to have a lower probability of disease-specific cure at the same detected tumor size, shed lethal metastases at smaller sizes (median: 19 mm for IDC versus 8 mm for NSCLC), have a TVDT that is almost half as long (median: 252 days for IDC versus 134 days for NSCLC). Consequently, NSCLC is associated with a lower mortality reduction from screening at the same screen detection threshold and screening interval. In summary, using a similar natural history model of cancer, we quantify the disease-specific curability attributable to screening for breast cancer, and separately lung cancer, in terms of the TVDT and onset of lethal metastases.

Distinct function of androgen receptor coactivator ARA70α and ARA70β in mammary gland development, and in breast cancer

Steroid receptor coactivators are important in regulating the function of the receptors in endocrine organ development and in cancers, including breast. Androgen receptor (AR) coactivator ARA70, was first identified as a gene fused to the ret oncogene and later characterized as an AR coactivator. We previously reported that the full length ARA70α functions as a tumor suppressor gene and that ARA70β functions as an oncogene in prostate cancer. Here we show that both ARA70α and ARA70β function as AR and estrogen receptor (ER) coactivators in breast cancer cells. However, ARA70α and ARA70β serve different functions in mammary gland development and breast cancer tumorigenesis. We observed hypoplastic development of mammary glands in MMTV driven ARA70α transgenic mice and overgrowth of mammary glands in ARA70β transgenic mice at virgin and pregnant stages. We determined that ARA70α inhibited cell proliferation, and that ARA70β promotes proliferation in MCF7 breast cancer cells. These effects were observed in hormone-free media, or in media with androgen or estrogen, though to varying degrees. Additionally, we observed that ARA70β strongly enhanced the invasive ability of MCF7 breast cancer cells in in vitro Matrigel assays. Significantly, decreased ARA70α expression is associated with increased tendency of breast cancer metastasis. In summary, ARA70α and ARA70β have distinct effects in mammary gland development and in the progression of breast cancer.

Management of women with BRCA mutations: a 41-year-old woman with a BRCA mutation and a recent history of breast cancer

Ms E, a 41-year-old BRCA1 mutation carrier, was diagnosed 4 years ago as having breast cancer and opted for breast-conserving therapy. Prior to receiving chemotherapy, she harvested her eggs through in vitro fertilization and subsequently used preimplantation genetic diagnosis; 3 months ago she delivered a healthy boy. This review examines the prevalence of BRCA mutations in women with breast cancer, as well as current recommendations for surgery and systemic therapy in these women. In particular, the risk of a contralateral breast cancer is reviewed to help guide the choice of prophylactic mastectomies vs breast-conserving therapy. The technology of preimplantation genetic diagnosis and genetic testing in relatives of mutation carriers is discussed.

Advances in nipple-sparing mastectomy: oncological safety and incision selection

BACKGROUND

With the evolution of breast reconstruction and oncoplastic techniques, more aesthetic mastectomies are being offered to patients. Nipple-sparing mastectomy (NSM) has been controversial, but an expanding body of published experience has allowed this concept to gain momentum.

OBJECTIVES

The authors review their experience with NSM.

METHODS

From 2007 to 2009, 112 consecutive patients (204 breasts) who were candidates for NSM presented to one of two private plastic surgery practices. All patients underwent preoperative magnetic resonance imaging to assess the size of the tumor, its distance from the nipple, and any additional disease within the ipsilateral/contralateral breast or axillae. Exclusion criteria included tumors larger than 3 cm, clinical invasion of the nipple-areolar complex, tumors within 2 cm of the nipple, evidence of multicentric disease, a positive intraoperative retroareolar frozen section, or nodal disease (excluding isolated immunohistochemistry positivity). Fourteen patients were excluded from the study for one of these reasons, leaving a total of 98 patients (186 breasts) who underwent NSM.

RESULTS

Risk-reducing mastectomies were performed on 45 patients. Therapeutic mastectomies were performed for Stage 0 cancer (ductal carcinoma in situ) in 26 patients, for Stage 1A in 24 patients, and for Stage 1B in three patients. Disease-free survival was calculated from the date of surgery to any local, regional, or distant relapse (whichever occurred first). As of the writing of this article, follow-up ranged from nine months to three years, and there has been no local or regional recurrence in any patient.

CONCLUSIONS

NSM is evolving and should be considered a good treatment option in carefully-selected patients. These findings add to the growing body of evidence showing that, with proper patient selection and operative technique, NSM is a safe and effective intervention for patients requiring therapeutic or prophylactic mastectomy.

Breast cancer incidence in the randomized PEARL trial of lasofoxifene in postmenopausal osteoporotic women

BACKGROUND

Currently available selective estrogen receptor modulators reduce the risk of breast cancer, but they are not widely used. In the Postmenopausal Evaluation and Risk-Reduction with Lasofoxifene (PEARL) trial, lasofoxifene was shown to reduce the risk of estrogen receptor-positive (ER+) breast cancer, nonvertebral and vertebral fractures, coronary artery disease, and stroke, but the effects on total breast cancer (invasive and ductal carcinoma in situ, ER+ and estrogen receptor-negative [ER-]) and ER+ invasive breast cancer are unknown.

METHODS

Postmenopausal women (n = 8556) aged 59-80 years with low bone density and normal mammograms were randomly assigned to two doses of lasofoxifene (0.25 and 0.5 mg) or placebo. The primary endpoints of the PEARL trial were incidence of ER+ breast cancer and nonvertebral fractures at 5 years. A nested case-control study of 49 incident breast cancer case patients and 156 unaffected control subjects from the PEARL trial was performed to evaluate treatment effects on risk of total and ER+ invasive breast cancer by baseline serum estradiol and sex hormone-binding globulin levels using logistic regression models. Cox proportional hazards models were used to evaluate risk of total breast cancer and ER+ invasive breast cancer using intention-to-treat analysis. All statistical tests were two-sided.

RESULTS

Breast cancer was confirmed in 49 women. Compared with placebo, 0.5 mg of lasofoxifene statistically significantly reduced the risk of total breast cancer by 79% (hazard ratio = 0.21; 95% confidence interval [CI] = 0.08 to 0.55) and ER+ invasive breast cancer by 83% (hazard ratio = 0.17; 95% CI = 0.05 to 0.57). The effects of 0.5 mg of lasofoxifene on total breast cancer were similar regardless of Gail score, whereas the effects were markedly stronger for women with baseline estradiol levels greater than the median (odds ratio = 0.11; 95% CI = 0.02 to 0.51) vs those with levels less than the median (odds ratio = 0.78; 95% CI = 0.16 to 3.79; P(interaction) = .04).

CONCLUSION

A 0.5-mg dose of lasofoxifene appears to reduce the risks of both total and ER+ invasive breast cancer in postmenopausal women with osteoporosis.

Overview of the randomized trials of radiotherapy in ductal carcinoma in situ of the breast

Individual patient data were available for all four of the randomized trials that began before 1995, and that compared adjuvant radiotherapy vs no radiotherapy following breast-conserving surgery for ductal carcinoma in situ (DCIS). A total of 3729 women were eligible for analysis. Radiotherapy reduced the absolute 10-year risk of any ipsilateral breast event (ie, either recurrent DCIS or invasive cancer) by 15.2% (SE 1.6%, 12.9% vs 28.1% 2 P <.00001), and it was effective regardless of the age at diagnosis, extent of breast-conserving surgery, use of tamoxifen, method of DCIS detection, margin status, focality, grade, comedonecrosis, architecture, or tumor size. The proportional reduction in ipsilateral breast events was greater in older than in younger women (2P < .0004 for difference between proportional reductions; 10-year absolute risks: 18.5% vs 29.1% at ages <50 years, 10.8% vs 27.8% at ages ≥ 50 years) but did not differ significantly according to any other available factor. Even for women with negative margins and small low-grade tumors, the absolute reduction in the 10-year risk of ipsilateral breast events was 18.0% (SE 5.5, 12.1% vs 30.1%, 2P = .002). After 10 years of follow-up, there was, however, no significant effect on breast cancer mortality, mortality from causes other than breast cancer, or all-cause mortality.

Nutrient patterns and risk of breast cancer in Uruguay

OBJECTIVES

To explore the role of nutrient patterns in the etiology of breast cancer (BC) among Uruguayan women.

METHODS

A principal component analysis was conducted. The study included 442 newly diagnosed cases of BC and 442 hospitalized controls.

RESULTS

Two dietary patterns derived from factor analysis and were labeled as high-meat and antioxidants patterns. Whereas the high-meat pattern was directly associated with BC risk (OR for the highest versus the lowest quartile = 3.50, 95 % CI 1.94-6.30, p-value for trend <0.0001), the antioxidants pattern displayed a protective effect (OR=0.44, 95 % CI 0.27-0.74). Its negative association was stronger for postmenopausal than for premenopausal women (OR=0.63, 95% CI 0.51-0.79 vs. OR=0.89, 95% CI 0.50-1.56, respectively). Both strata were heterogeneous (p=0.004). The high-meat pattern was more associated with BC risk among patients with family history of BC compared with participants without it, but results did not differ by histology. In contrast, the antioxidants pattern was more associated with non-ductal cancers (OR=0.50 [95 % CI 0.35-0.69]) than with ductal cancers (OR=0.72, 95 % CI 0.58-0.88, heterogeneity p-value=0.03).

CONCLUSIONS

Results support an association between the high-meat and antioxidant dietary patterns and BC risk. Furthermore, findings suggest that gene-environmental interactions may be important in BC etiology.

Hormone therapy and breast cancer risk

Hormone therapy (HT) is the most efficacious intervention for the relief of climacteric symptoms. Controversies surrounding HT have left many women puzzled and afraid. Gynecologists are faced with long-standing beneficial assumptions challenged by an abundance of robust detrimental new data, with little guidance on how to interpret these findings. Prescriptions for HT (and incidence of breast cancers in some areas) have fallen over the last 3 years due to anxiety provoked about breast cancer risk and recurrence. The current 'clinical climate' is against HT. Due to a lack of effective alternatives, women suffering from estrogen-deficiency symptoms are still requesting objective information about HT, particularly those at higher risk of breast cancer or those with a past history of breast cancer. In this situation, discussion of the current clinical uncertainty surrounding the use of HT must be undertaken to ensure that women are adequately informed. The objective of this presentation is to provide a framework for understanding breast cancer risk associated with HT. What are the precise molecular mechanisms of estrogen and progestin in the initiation of breast cancer? Does the risk of estrogen-only therapy on breast cancer vary by dose, constituent, route and duration of administration and cessation of use? Does HT, in addition to increasing risk for breast cancer, affect the type of breast cancer (lobular and ductal) diagnosed? Is HT associated with breast cancers that have better prognostic factors? How relevant are the changes in mammographic breast density associated with HT for the evaluation of breast cancer risk? What is the additional global health risk/benefit ratio associated with the selective use of progesterone or progestin that may confer a significant cardiovascular benefit, such as drospirenone? It is currently assumed and tested that new hormones with particular pharmacological profiles may ultimately achieve their therapeutic goal of relieving climacteric symptoms without an associated moderate increased risk of breast cancer.

African-American and low-socioeconomic status patients have a worse prognosis for invasive ductal and lobular breast carcinoma: do screening criteria need to change?

BACKGROUND

Determine the effect of race, socioeconomic status (SES) and other demographic variables on outcomes of patients with invasive ductal and lobular breast cancer.

STUDY DESIGN

Florida cancer registry and inpatient hospital data were queried for patients diagnosed with invasive breast cancer from 1998 to 2002.

RESULTS

A total of 63,472 patients with breast cancer were identified. Overall, 90.5% of patients were Caucasian, 7.6% African American, and 8.7% Hispanic. African-American patients presented at a younger age and with more-advanced disease, 10.5% presented with breast cancer before the age of 40 years, and 22.4% before 45 years of age. African-American patients were less likely to undergo operations. Similarly, low-SES patients were less likely to have operations and presented more often with larger tumors. Stepwise multivariate analysis revealed a substantial drop in the hazard ratio for African-American patients once correction for stage of presentation was made, suggesting that disparities in breast cancer outcomes are, in part, a result of advanced stage at presentation. Race and low SES were independent predictors of worse prognosis when controlling for patient comorbidities and treatment.

CONCLUSIONS

Dramatic disparities by patient race and SES exist in breast cancer. Our study integrates previous smaller studies, providing comprehensive insight into African-American patients and their outcomes for breast cancer. Earlier screening programs and greater access to cancer care for the poor and African Americans are needed. Successful institution of such programs will not completely erase disparities in outcomes for breast cancer in African-American patients.

Proportion of invasive breast cancer attributable to risk factors modifiable after menopause

A number of breast cancer risk factors are modifiable later in life, yet the combined impact of the population changes in these risk factors on breast cancer incidence is not known to have been evaluated. The population attributable risk (PAR) associated with individual risk factors and the summary PAR for sets of modifiable and nonmodifiable risk factors were estimated by using data on 3,499 invasive breast cancer cases and 4,213 controls from a population-based study in Wisconsin, Massachusetts, and New Hampshire, conducted from 1997 to 2001. The summary PAR for factors modifiable after menopause, including current postmenopausal hormone use, recent alcohol consumption, adult weight gain, and recent recreational physical activity, was 40.7%. Of the individual modifiable factors, the highest PARs were observed for weight gain (21.3%) and recreational physical activity (15.7%), which together showed a summary PAR of 33.6%. The summary PAR for factors not modifiable after menopause, including family history of breast cancer, personal history of benign breast disease, height at age 25 years, age at menarche, age at menopause, age at first birth, and parity, was 57.3%. These findings suggest that a substantial fraction of postmenopausal breast cancer may be avoided by purposeful changes in lifestyle later in life.

Relationship between bone mass, invasive breast cancer incidence and raloxifene therapy in postmenopausal women with low bone mass or osteoporosis

OBJECTIVE

To evaluate the relationship between bone mass and risk of breast cancer and to determine the effect of raloxifene therapy on breast cancer incidence in women categorized by bone mass into low bone mass and osteoporosis subgroups.

DESIGN

In this post hoc analysis, data were analyzed from the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, enrolling postmenopausal women with low bone mass (N = 7705), and the Continuing Outcomes Relevant to Evista (CORE) trial, a follow-up to MORE enrolling 4011 MORE participants. Total follow-up was for up to 8 years. Women with a total hip bone mineral density (BMD) T-score < -1 to > -2.5 or T-score < or = -2.5 (referent, NHANES III database) were classified as having low bone mass or osteoporosis, respectively. Women with a pre-existing vertebral fracture were considered as having osteoporosis irrespective of BMD T-score. Analyses were performed for invasive breast cancers and invasive estrogen-receptor (ER) positive breast cancers.

RESULTS

Women with low bone mass (N = 3829) had a twofold higher incidence of invasive ER-positive breast cancer than those with osteoporosis (N = 3836) (HR 2.13, 95% CI 1.12-4.03). The incidence of all invasive breast cancers did not differ significantly between the bone mass groups. The incidences of invasive and invasive ER-positive breast cancers were 65-78% lower in women assigned raloxifene versus placebo in both the low bone mass and osteoporosis groups (p < 0.05).

CONCLUSIONS

In this post hoc analysis of postmenopausal women participating in MORE and CORE, bone mass was a predictor of invasive ER-positive breast cancer. Raloxifene treatment reduced the risk of invasive and invasive ER-positive breast cancers in women with low bone mass and those with osteoporosis. Since participants were older postmenopausal women with low bone mass, whether these findings can be generalized to other postmenopausal women is unclear.

Atypia in random periareolar fine-needle aspiration affects the decision of women at high risk to take tamoxifen for breast cancer chemoprevention

Random periareolar fine-needle aspiration (RPFNA) is a research procedure designed to (a) evaluate short-term breast cancer risk in women at high risk for developing breast cancer, and (b) track response to chemoprevention. Of import, cellular atypia in breast RPFNA is prospectively associated with a 5.6-fold increase in breast cancer risk in women at high risk. Among 99 women attending a clinic for high-risk breast cancer, we explored the effects of RPFNA cytology results on decision making pertaining to the use of tamoxifen for breast cancer chemoprevention. No patient with nonproliferative or hyperplastic cytology subsequently elected to take tamoxifen. Only 7% of subjects with borderline atypia elected to take tamoxifen. In contrast, 50% with atypia elected to take tamoxifen. These results suggest that the provision of a biomarker of short-term risk can affect the motivation to take tamoxifen for chemoprevention. This conclusion is informative given that tamoxifen, due to its side effects, is often underused by women at high risk of developing breast cancer. Further research is needed to determine the mechanisms through which RPFNA results affect the decision to use tamoxifen, or any other breast cancer chemopreventive agent.

Dietary lignan intake and postmenopausal breast cancer risk by estrogen and progesterone receptor status

BACKGROUND

Studies conducted in Asian populations have suggested that high consumption of soy-based foods that are rich in isoflavone phytoestrogens is associated with a reduced risk of breast cancer. However, the potential associations of other dietary phytoestrogens--i.e., the lignans or their bioactive metabolites, the enterolignans--with the risk of breast cancer are unclear.

METHODS

We prospectively examined associations between the risk of postmenopausal invasive breast cancer and dietary intakes of four plant lignans (pinoresinol, lariciresinol, secoisolariciresinol, and matairesinol) and estimated exposure to two enterolignans (enterodiol and enterolactone), as measured with a self-administered diet history questionnaire, among 58,049 postmenopausal French women who were not taking soy isoflavone supplements. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards regression models. Analyses were further stratified by the combined estrogen and progesterone receptor (ER/PR) status of the tumors. Statistical tests were two-sided.

RESULTS

During 383,425 person-years of follow-up (median follow-up, 7.7 years), 1469 cases of breast cancer were diagnosed. Compared with women in the lowest intake quartiles, those in the highest quartile of total lignan intake (>1395 microg/day) had a reduced risk of breast cancer (RR = 0.83, 95% CI = 0.71 to 0.95, P(trend) = .02, 376 versus 411 cases per 100,000 person-years), as did those in the highest quartile of lariciresinol intake (RR = 0.82, 95% CI = 0.71 to 0.95, P(trend) = .01). The inverse associations between phytoestrogen intakes and postmenopausal breast cancer risk were limited to ER- and PR-positive disease (e.g., RR for highest versus lowest quartiles of total plant lignan intake = 0.72, 95% CI = 0.58 to 0.88, P(trend) = .01, 174 versus 214 cases per 100,000 person-years, and RR for highest versus lowest quartiles of total enterolignan level = 0.77, 95% CI = 0.62 to 0.95, P(trend) = .01, 164 versus 204 cases per 100,000 person-years).

CONCLUSIONS

High dietary intakes of plant lignans and high exposure to enterolignans were associated with reduced risks of ER- and PR-positive postmenopausal breast cancer in a Western population that does not consume a diet rich in soy.

Longitudinal measurement of clinical mammographic breast density to improve estimation of breast cancer risk

BACKGROUND

Whether a change over time in clinically measured mammographic breast density influences breast cancer risk is unknown.

METHODS

From January 1993 to December 2003, data that included American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) breast density categories (1-4 in order of increasing density) were collected prospectively on 301,955 women aged 30 and older who were not using postmenopausal hormone replacement therapy and underwent at least two screening mammography examinations; 2639 of the women were diagnosed with breast cancer within 1 year of the last examination. Women's first and last BI-RADS breast density (average 3.2 years apart) and logistic regression were used to model the odds of having invasive breast cancer or ductal carcinoma in situ diagnosed within 12 months of the last examination by change in BI-RADS category. Rates of breast cancer adjusted for age, mammography registry, and time between screening examinations were estimated from this model. All statistical tests were two-sided.

RESULTS

The rate (breast cancers per 1000 women) of breast cancer was higher if BI-RADS breast density category increased from 1 to 2 (5.6, 95% confidence interval [CI] = 4.7 to 6.9) or 1 to 3 (9.9, 95% CI = 6.4 to 15.5) compared to when it remained at BI-RADS density of 1 (3.0, 95% CI = 2.3 to 3.9; P<.001 for trend). Similar and statistically significant trends between increased or decreased density and increased or decreased risk of breast cancer, respectively, were observed for women whose breast density category was initially 2 or 3 and changed categories. BI-RADS density of 4 on the first examination was associated with a high rate of breast cancer (range 9.1-13.4) that remained high even if breast density decreased.

CONCLUSION

An increase in BI-RADS breast density category within 3 years may be associated with an increase in breast cancer risk and a decrease in density category with a decrease in risk compared to breast cancer risk in women in whom breast density category remains unchanged. Two longitudinal measures of BI-RADS breast density may better predict a woman's risk of breast cancer than a single measure.

Modeling the effect of tamoxifen chemoprevention on long-term mortality in white women at high risk of breast cancer

Tamoxifen has long been studied as a drug to treat breast cancer and now for its preventive effect. Intermediate results from studies on the preventive effect of tamoxifen vs. placebo endorsed tamoxifen's efficacy after a short follow-up. Effect of tamoxifen on long-term survival was simulated in women at a high risk of breast cancer. The model allows for tamoxifen effect on breast cancer according to estrogen receptor status, endometrial cancer, and pulmonary embolism. A virtual cohort of 200,000 white women was split into two treatment arms (placebo vs. tamoxifen), two age groups (35-49 and 50-74), and followed-up for 20 years. Incidence rates stemmed from the National Surgical Adjuvant Breast and bowel Project-P1, or the chemoprevention trials overview by Cuzick et al., and relative survival probabilities from surveillance, epidemiology, and end results. Six hypotheses of tamoxifen effects and their variations along time were considered. In the National Surgical Adjuvant Breast and Bowel Project-based results, women aged 35-49 took advantage of tamoxifen whatever the follow-up duration and hypothesis, except the one of only side effects remaining 15 years after treatment withdrawal. In the overview-based results, the advantage existed only when effect on pulmonary embolism stopped. Women aged 50-74 experienced underwent tamoxifen side effects that outweighed advantages whatever the follow-up duration and hypothesis, except the one of only beneficial remaining effect 15 years after treatment withdrawal. Overall, the slight positive effect of tamoxifen on long-term mortality should be cautiously interpreted for young women. In women aged over 50 years, however, tamoxifen chemoprevention could not be recommended.

Prognostic factors in stage-i (T1N0) breast carcinoma patients: who needs adjuvant systemic treatment?

There is no consensus about the need of adjuvant therapy in T(1)N(0) breast carcinoma patients. To select a subgroup of these patients who may benefit from adjuvant systemic therapy, prognostic factor analyses were carried out using chi-square test and Cox regression analysis in 187 patients data in this retrospective study. Primary endpoint was distant metastasis (DM). The multivariate Cox analysis showed that age group (<or=35 years vs >35 years, p=0.01; Hazard Ratio [HR], 15.4; 95% Confidence Interval [CI], 1.8-133.0), tumor size (>1 cm vs <or=1 cm, p=0.002; HR,3.5; CI:1.2-13.4) and LVI (yes vs no, p=0.002; HR,34.7; CI:3.6-326.0) were strongly associated with DM. From this analysis, a risk estimation model for DM was constructed. Whereas patients at low risk had a 96% distant metastasis-free survival, this rate for those at high risk had a 37% (p<0.00001). According to the proposed model including age, tumor size and LVI, the patients at high risk might benefit from adjuvant systemic therapy.

HER2 (erbB-2)-targeted effects of the ϖ-3 polyunsaturated. Fatty acid α-linolenic acid (ALA; 18:3n-3) in breast cancer cells: the «fat features» of the «Mediterranean diet» as an «anti-HER2 cocktail»

BACKGROUND

Data derived from epidemiological and experimental studies suggest that alphalinolenic acid (ALA; 18:3n-3), the main omega-3 polyunsaturated fatty acid (PUFA) present in the Western diet, may have protective effects in breast cancer risk and metastatic progression. A recent pilot clinical trial assessing the effects of ALA-rich dietary flaxseed on tumor biological markers in postmenopausal patients with primary breast cancer demonstrated significant reductions in tumor growth and in HER2 (erbB-2) oncogene expression.

HYPOTHESIS

The molecular mechanism by which ALA inhibits breast cancer cell growth and metastasis formation may involve a direct regulation of HER2, a well-characterized oncogene playing a key role in the etiology, progression and response to some chemo- and endocrine therapies in approximately 20% of breast carcinomas.

METHODS

Using HER2-specific ELISA, flow cytometry, immunofluorescence microscopy, Western blotting, RT-PCR and HER2 promoter-reporter analyses, we characterized the effects of exogenous supplementation with ALA on the expression of HER2 oncogene, a master key player in the onset and metastasis formation of breast cancer disease. Metabolic status (MTT) assays were performed to evaluate the nature of the cytotoxic interaction between ALA and the humanized anti-HER2 monoclonal antibody trastuzumab (Herceptin). To study these issues we used BT-474 and SKBr-3 breast cancer cells, which naturally exhibit amplification of the HER2 oncogene.

RESULTS

ALA treatment dramatically suppressed the expression of HER2-coded p185Her-2/neu oncoprotein as determined by ELISA, flow cytometry, immunofluorescence microscopy and immunoblotting techniques. Interestingly, ALA-induced down-regulation of p185Her-2/neu correlated with a transcriptional response as no HER2 mRNA signal could be detected by RT-PCR upon treatment with optimal concentrations of ALA (up to 20 microM). Consistent with these findings, ALA exposure was found to dramatically repress the activity of a Luciferase reporter gene driven by the HER2 promoter. Moreover, the nature of the cytotoxic interaction between ALA and trastuzumab (Herceptin) revealed a significant synergism as assessed by MTT-based cell viability assays.

CONCLUSIONS

i) These findings reveal that the omega-3 PUFA ALA suppresses overexpression of HER2 oncogene at the transcriptional level, which, in turn, interacts synergistically with anti-HER2 trastuzumab- based immunotherapy. ii) Our results molecularly support a recent randomized double-blind placebo-controlled clinical trial suggesting that ALA may be a potential dietary alternative or adjunct to currently used drugs in the management of HER2-positive breast carcinomas. iii) Considering our previous findings demonstrating the <<HER2 upregulatory actions>> of the omega-6 PUFA linolenic acid (LA; 18:2n-6) and the <<HER2 down-regulatory actions >> of the omega-3 PUFA docosahexaenoic acid (DHA; 22:6n-3) and of the omega-9 monounsaturated fatty acid oleic acid (OA; 18:1n-9), it is reasonable to suggest that a low omega-6/omega-3 PUFA ratio and elevated MUFA levels, the two prominent <<fat features>> of the <<Mediterranean diet>>, should be extremely efficient at blocking HER2 expression in breast cancer cells.

Celecoxib decreases prostaglandin E2 concentrations in nipple aspirate fluid from high risk postmenopausal women and women with breast cancer

BACKGROUND

Celecoxib inhibits PGE2 production in cancerous tissue. We previously reported that PGE2 levels in nipple aspirate fluid (NAF) and plasma were not decreased in women at increased breast cancer risk who received celecoxib 200 mg twice daily (bid). The endpoints of the current study were to determine if a short course of celecoxib 400 mg bid would decrease PGE2 levels in women 1) at increased breast cancer risk, and 2) with established breast cancer.

METHODS

NAF and plasma samples were collected before, 2 weeks after taking celecoxib 400 mg bid, and two weeks after washout from 26 women who were at increased breast cancer risk. From 13 women with newly diagnosed breast cancer, NAF from the incident breast and plasma were collected before and on average 2 weeks after taking celecoxib. Additionally, in nine of the 13 women with breast cancer, NAF was collected from the contralateral breast.

RESULTS

No consistent change in NAF or plasma PGE2 levels was noted in high risk premenopausal women. NAF PGE2 levels decreased after celecoxib administration in postmenopausal high risk women (p = 0.02), and in both the NAF (p = 0.02) and plasma (p = 0.03) of women with breast cancer.

CONCLUSION

Celecoxib 400 mg bid taken on average for 2 weeks significantly decreased NAF, but not plasma, PGE2 levels in postmenopausal high risk women, and decreased both NAF and plasma PGE2 levels in women with newly diagnosed breast cancer. PGE2 levels may predict celecoxib breast cancer prevention and treatment efficacy. Our observations are preliminary, and larger studies to confirm and extend these findings are warranted.

Enhancer of Zeste 2 as a Marker of Preneoplastic Progression in the Breast: Figure 1

Amplification of the Polycomb group transcriptional repressor Enhancer of Zeste 2 (EZH2) occurs in various malignancies including breast cancer, where its overexpression is associated with poor outcome. We found that EZH2 is up-regulated in ductal carcinoma in situ, atypical ductal hyperplasia, and even morphologically normal breast epithelial cells from women who have an increased risk of breast cancer. This review discusses how EZH2 may promote neoplastic conversion and it surveys the evidence suggesting that EZH2 may offer a clinical tool to help identify patients at risk for developing breast cancer before precursor lesions are histologically evident.

Selective reduction of estrogen receptor (ER) positive breast cancer occurrence by estrogen receptor modulators supports etiological distinction between ER positive and ER negative breast cancers

Reports that selective estrogen receptor modulators (SERMs) reduce occurrence of only estrogen receptor (ER) positive tumors strongly support the etiological distinction between ER positive and ER negative breast cancers. Based on these evidences three concepts are described: Concept I. The occurrence of ER negative tumor cells might be a consequence of the clonal selection among tumor cells. This would lead to mosaicism in the ER expression. If ER negative cells become the most prevalent clone, the patient will be diagnosed to have an ER negative breast cancer. Since all cancers start as ER positive, SERMs should equally prevent occurrence of ER positive and ER negative breast cancers, but this prediction is evidently wrong. Concept II. Mammary ducts normally contain ER positive and ER negative cells, both prone to malignancy. Cancer occurrence in ductal cells that normally lack ER would be unrelated to estrogen exposure or SERMs protection. Estrogen and SERMs can influence cancer occurrence only in ER positive ductal cells. The main drawback is that this concept does not predict occurrence of mosaicism in ER expression among tumor cells. Unified Concept I and II. To overcome limitations of described concept a unified concept is presented. Cancers from ER positive ductal cells start as pure ER positive tumors and those from ER negative ductal cells as pure ER negative tumors. During the preclinical phase, in some ER positive tumors, clonal selection introduces ER negative clones. These tumors become mosaic in the cellular ER expression, some of them predominantly ER positive other ER negative. Estrogen deprivation, or SERMs can help mostly to patients with pure ER positive, or mosaic ER positive tumors. Since the dominant metastatic clone can have different ER status from the primary breast tumor, both surprising successes and failures of endocrine therapy can be expected in tumors with mosaic ER expression.

Differences in Screening Mammography Outcomes Among White, Chinese, and Filipino Women

BACKGROUND

The accuracy of screening mammography among Asian women in the United States has received little attention. We determined whether the accuracy of screening mammography for Chinese and Filipino women differs from that of white women.

METHODS

We examined a cohort of white, Chinese, and Filipino women 40 years and older who underwent 200,402, 72,604, and 19,087 screening examinations, respectively, between January 1986 and December 2001 in San Francisco County, California, of whom 2177 were diagnosed with breast cancer within 12 months of a screening examination. By linking screening examinations to the regional Surveillance, Epidemiology and End Results program and the California Cancer Registry, we identified the occurrence of any invasive cancer or ductal carcinoma in situ and then calculated the rate of cancer per 1000 screenings and the sensitivity of mammography.

RESULTS

The rate of invasive breast cancer per 1000 screenings was 45% lower for Chinese than for white women aged 50 to 69 years (3.8 vs 6.9; P<.001) and 29% lower for Filipino than for white women (4.9 vs 6.9; P = .03). Rates of ductal carcinoma in situ were similar across all ethnic groups (1.6-1.7 per 1000 screenings; P>or=.60). The sensitivity of mammography was similar for white, Chinese, and Filipino women (81.6%-84.3%; P>.30).

CONCLUSIONS

Screening mammography has similar accuracy among white, Chinese, and Filipino women, although the absolute benefit of screening, in terms of breast cancer deaths averted, is likely to be less among Asian women because the rates of invasive cancer are lower compared with white women of similar age. Overdiagnosis of ductal carcinoma in situ with screening mammography among Asian women is likely to be comparable to that of white women because the rate of ductal carcinoma in situ was similar in all the examined ethnic groups.

Parity-induced changes in global gene expression in the human mammary gland

The protective effect of an early first full-term pregnancy in relation to breast cancer risk is well established, but the molecular and cell-specific changes in the human mammary gland involved remain unclear. To identify the molecular changes associated with pregnancy-induced differentiation, we analysed the global gene expression profiles of normal mammary tissues from both a parous and a nulliparous woman, using serial analysis of gene expression. This approach allowed us to identify sets of genes, known and unknown, that are differentially expressed in parous versus age-matched nulliparous mammary gland tissues. The normal mammary gland of a multiparous woman is characterized by several known differentiation markers such as casein kappa, casein beta, keratin 14, CCAAT/enhancer binding protein beta and delta and adipsin. Candidate genes involved in cytoarchitectural remodelling and growth inhibition with a potential role in pregnancy-induced protection against breast cancer were also observed. Several genes that are highly expressed in the nulliparous mammary gland and that are lost after pregnancy, encode for growth promoting, cytoskeletal and extracellular matrix proteins. One of these genes, the small breast epithelial mucin, is almost completely downregulated upon a first full-term pregnancy but is known to be expressed in more than 90% of invasive ductal carcinomas.

Ki-67 Expression in Benign Breast Ductal Cells Obtained by Random Periareolar Fine Needle Aspiration

Ki-67 expression in ductal cells obtained by random periareolar fine needle aspiration (RPFNA) is currently being used as a response biomarker in phase II breast cancer chemoprevention trials; however, Ki-67 in RPFNA has not been well studied as a risk predictor for cancer, which would support its use as a response indicator. We examined the expression of Ki-67 in RPFNA specimens with hyperplasia +/- atypia obtained from 147 women at high risk for development of breast cancer. Median Ki-67 was 1.4% (range 0-24%). Ki-67 was higher in specimens from women < 50 versus those > or = 50 (median 2% versus 0.6%; P = 0.006) and from premenopausal women versus postmenopausal women (P = 0.037); however, hormone replacement therapy (predominately low-dose estrogen without progestins) had no effect. By univariate analysis, Ki-67 was positively correlated with ductal cell number (P = 0.001) and hyperplasia with atypia (P = 0.007). By multivariable analysis, the proportion of ductal cells expressing Ki-67 was again predicted by cell number, which, in turn, was predicted by cytologic atypia. The association of Ki-67 expression with cytologic atypia, a known risk factor for development of breast cancer, provides preliminary justification for its use as a response biomarker in phase II chemoprevention trials.

Fruits, vegetables, and micronutrients in relation to breast cancer modified by menopause and hormone receptor status

Whether fruit, vegetable, and antioxidant micronutrient consumption is associated with a reduction in breast cancer incidence remains unresolved. To address this issue, we analyzed data from a large population-based case-control study, with consideration given to whether the associations varied with menopausal status or with clinical characteristics of the cases' disease. Study participants completed a modified Block food frequency questionnaire, which included assessment of the frequency and portion sizes of 13 fruits and fruit juices and 16 vegetables and the use of multiple and single vitamin supplements. Statistical analyses were done on 1,463 cases and 1,500 controls. Among postmenopausal women, reduced odds ratios [OR; 95% confidence intervals (95% CI)] were noted for the highest fifth, as compared with the lowest fifth, of intake of any vegetables [0.63 (0.46-0.86); P for trend < 0.01] and leafy vegetables [0.66 (0.50-0.86); P for trend = 0.03] after controlling for age and energy intake. Adjusted ORs (95% CIs) were also decreased for postmenopausal breast cancer in relation to high intake of carotenoids, alpha-carotene, beta-carotene, lutein, and particularly lycopene [0.66 (0.48-0.90); P for trend = 0.03]. Inverse associations for fruits and vegetables were stronger for postmenopausal women with estrogen receptor (ER)+ tumors (OR, 0.65; 95% CI, 0.51-0.82) than ER- tumors (OR, 0.92; 95% CI, 0.64-1.32), but results were less consistent for micronutrients. No similarly reduced associations were observed among premenopausal women. ORs did not appreciably differ by in situ or invasive breast cancer or by whether cases had begun chemotherapy. Our results support an inverse association for fruit and vegetable intake among postmenopausal but not premenopausal breast cancer, which may be more pronounced among women with ER+ tumors.

Causation and prevention of solely estrogen-induced oncogenesis: similarities to human ductal breast cancer

Estrogens are intimately involved in the causation of some of the most prevalent cancers afflicting women, particularly, breast, endometrial, cervico-vaginal, and possibly ovarian. Therefore, it has become particularly pertinent to elucidate the molecular changes and mechanisms whereby estrogens elicit their oncogenic actions so that better prevention strategies can be developed. The estrogen-induced Syrian hamster tumors of the kidney have emerged as one of the most intensively studied in-vivo models in solely estrogen-induced oncogenesis. An advantage of this model is that the tumors occur in the absence of any intervening morphologic changes, but rather they are the result of the continuous progression of a subset of interstitial stem cells in the kidney leading to tumor formation. Evidence is presented that the origin of these tumors is derived from ectopic "uterine" stem cells, which are responsive to estrogenic hormones. The other animal tumor model studied is the highly sensitive estrogen-induced mammary tumors of female ACI rats. Their steroid receptor and other gene alterations have been delineated. Importantly, a crucial early event in this solely estrogen-induced oncogenic process, common to both animal tumor models, is the overexpression and amplification of c-myc and its protein product. Chromosomal instability, in both early and large well-established frank tumors, is another important characteristic found during early E-induced oncogenesis. These features have been shown to be characteristic of human ductal carcinomas in-situ and in primary invasive ductal breast carcinomas. The molecular alterations seen are considered crucial in eliciting estrogen-induced oncogenesis and have established for the first time a direct causal link between estrogen and the induction of chromosomal instability and aneuploidy in these estrogen-associated neoplasms.

Elevated expression of cyclooxygenase-2 in breast cancer and ductal carcinoma in situ has no correlation with established prognostic markers

BACKGROUND AND OBJECTIVES

Elevated expression of cyclooxygenase-2 (COX-2) has been established to be a feature of breast cancer. There has been inconsistency in the literature regarding the precise significance of this-some studies have found no clinicopathological relevance at all, whilst others have concluded COX-2 expression is an important biomarker in invasive disease and pre-cancerous lesions, correlating with poor prognostic features. We studied COX-2 expression in invasive ductal cancer (IDC) specimens and ductal carcinoma in situ (DCIS) in order to clarify these issues.

METHOD

Archival specimens of IDC and DCIS (n = 39) were stained with a polyclonal antibody to COX-2. Results were correlated with recognised clinicopathological parameters.

RESULTS

COX-2 expression occurred in 36.7% of IDCs and 54.5% of DCIS lesions. There was no correlation between increased expression and any clinicopathological features. COX-2 expression did not occur in adjacent non-cancerous tissue (ANCT).

CONCLUSION

We have confirmed that COX-2 expression does occur in invasive cancers, in DCIS, and is not associated with established prognostic markers. The presence of COX-2 expression in DCIS and invasive cancers has positive implications for the future prevention and treatment of breast cancer with COX-2 inhibitors. A large proportion of tumours are, however, COX-2 negative and may be poor candidates for COX-2 suppression.

Women need better information about routine mammography

Scientists continue to argue about the benefits of breast screening, but ultimately decisions about screening should be made by women themselves. To make this decision, however, women need to fully understand both the benefits and the potential harms

Is there any association between uterine malignant mixed Mullerian tumour, breast cancer and prolonged tamoxifen treatment?

Uterine malignant mixed Mullerian tumour is a very aggressive tumour of unknown aetiology. Previous pelvic irradiation, excessive oestrogen exposure, obesity and nulliparity have been incriminated in its aetiology. There is a paucity of data on the association between uterine mixed Mullerian tumour breast cancer and prolonged tamoxifen treatment. We report four patients who took tamoxifen for more than 7 years for breast cancer prior to their diagnosis with uterine mixed Mullerian tumour and also reviewed similar cases reported in the medical literature. The purpose of this article is to draw the attention of other professionals on this subject.