Highlights from recent National Surgical Adjuvant Breast and Bowel Project studies in the treatment and prevention of breast cancer

Sex hormones and stroke: Beyond estrogens

Stroke risk and poor stroke outcomes in postmenopausal women have usually beeen attributed to decreased levels of estrogen. However, two lines of evidence suggest that this hormone may not be solely responsible for elevated stroke risk in this population. First, the increased risk for CVD and stroke occurs much earlier than menopause at a time when estrogen levels are not yet reduced. Second, estrogen therapy has not successfully reduced stroke risk in all studies. Other sex hormones may therefore also contribute to stroke risk. Prior to menopause, levels of the gonadotrophin Follicle Stimulating Hormone (FSH) are elevated while levels of the gonadal peptide inhibin are lowered, indicating an overall decrease in ovarian reserve. Similarly, reduced estrogen levels at menopause significantly increase the ratio of androgens to estrogens. In view of the evidence that androgens may be unfavorable for CVD and stroke, this elevated ratio of testosterone to estrogen may also contribute to the postmenopause-associated stroke risk. This review synthesizes evidence from different clinical populations including natural menopause, surgical menopause, women on chemotherapy, and preclinical stroke models to dissect the role of ovarian hormones and stroke risk and outcomes.

Rat models of 17β-estradiol-induced mammary cancer reveal novel insights into breast cancer etiology and prevention

Numerous laboratory and epidemiologic studies strongly implicate endogenous and exogenous estrogens in the etiology of breast cancer. Data summarized herein suggest that the ACI rat model of 17β-estradiol (E2)-induced mammary cancer is unique among rodent models in the extent to which it faithfully reflects the etiology and biology of luminal types of breast cancer, which together constitute ~70% of all breast cancers. E2 drives cancer development in this model through mechanisms that are largely dependent upon estrogen receptors and require progesterone and its receptors. Moreover, mammary cancer development appears to be associated with generation of oxidative stress and can be modified by multiple dietary factors, several of which may attenuate the actions of reactive oxygen species. Studies of susceptible ACI rats and resistant COP or BN rats provide novel insights into the genetic bases of susceptibility and the biological processes regulated by genetic determinants of susceptibility. This review summarizes research progress resulting from use of these physiologically relevant rat models to advance understanding of breast cancer etiology and prevention.

Baseline E(2) levels are higher in BRCA2 mutation carriers: a potential target for prevention?

PURPOSE

BRCA gene mutations and elevated serum estradiol (E(2)) are well-known risk factors for breast cancer. The aim of this study was to investigate the association between BRCA gene mutations and serum E(2) level.

METHODS

We measured baseline (menstrual cycle day 2-3) E(2) levels of 96 women with breast cancer who underwent BRCA testing.

RESULTS

The mean age, parity, and age at menarche did not differ between women with and without BRCA1/2 mutations. Basal serum E(2) level was significantly higher in women with BRCA2 mutations compared to women with BRCA1 mutations or without BRCA mutations (71.7 ± 41.6 vs. 45.5 ± 20.7 vs. 38.5 ± 12.6 pg/ml in BRCA2 mutation carriers, BRCA1 mutation carriers, and non-carriers, respectively, p value = 0.03). Women with BRCA2 mutations had 3.1 times as great risk for high basal E(2) level (>48 pg/ml) as women without BRCA mutations after adjusting for age and BMI (95 % confidence interval: 1.3, 7.6). BRCA mutation carriers with high serum E(2) level were significantly younger than the carriers with low serum E(2) level (31.4 ± 3.1 vs. 34.7 ± 4.9 years, p = 0.04).

CONCLUSIONS

In this pilot study, we found an association between high basal serum E(2) levels and BRCA2 mutations. Our results suggest that increased production of E(2) may have a role in the pathogenesis of BRCA2-mutation-related breast cancer.

Effect of primary prophylactic granulocyte-colony stimulating factor use on incidence of neutropenia hospitalizations for elderly early-stage breast cancer patients receiving chemotherapy

OBJECTIVE

Chemotherapy is vital for breast cancer management, but early-onset toxicities like neutropenia hinder its administration, especially in the elderly. Primary prophylactic (PP) use of granulocyte-colony stimulating factors (G-CSF) helps prevent neutropenia and its complications while receiving chemotherapy. Nevertheless, evidence supporting the effectiveness of PPG-CSF in the elderly is limited. Thus, the American Society of Clinical Oncology (ASCO) guidelines for PPG-CSF use in the elderly are not explicit. This study analyzed the effects of administration of PPG-CSF and duration of administration on the occurrence of chemotherapy-induced neutropenia hospitalizations in elderly breast cancer patients.

METHODS

This retrospective observational study of newly diagnosed breast cancer patients receiving chemotherapy used Surveillance, Epidemiology, and End Results-Medicare data from 1994 to 2003. To account for the nonrandom nature of the observational data, a nonparametric matching technique was used to preprocess the data before parametrically estimating the treatment effects.

RESULTS

Administration of PPG-CSF during the first course chemotherapy reduced neutropenia hospitalizations by 16% within the first 3 months and 17% within the first 6 months of chemotherapy initiation (P < 0.05). Hospitalization rates within the first 3 months of chemotherapy initiation were 3 times higher in women receiving less than 5 consecutive days of PPG-CSF compared with women receiving PPG-CSF for 5 or more days (P < 0.05). Hospitalization rates within the first 1 and 6 months were also lower with longer PPG-CSF duration (≥5 d) (P < 0.10).

CONCLUSIONS

PPG-CSF use is associated with reductions in in-patient healthcare utilization. These findings have implications for ASCO guidelines and Medicare coverage policies for PPG-CSF administration in elderly breast cancer patients.

Outcomes of screening-detected ductal carcinoma in situ treated with wide excision alone

BACKGROUND

Ductal carcinoma in situ (DCIS) is commonly identified on screening mammography. Standard treatment for localized DCIS is wide local excision (WLE) and adjuvant radiotherapy. This approach represents overtreatment in many cases, where the DCIS would never have become clinically significant, or where less intensive treatment would have been satisfactory. We reviewed the medium-term outcome of a cohort of screen detected DCIS patients treated mainly with WLE without radiotherapy.

METHODS

All patients diagnosed with DCIS at NorthWestern BreastScreen between January 1994 and December 2005 were identified from a prospective database. Demographic, pathological, treatment, and outcome data were collected and analyzed. Survival and local recurrence (LR) rates were determined, and associations between various factors and recurrence were analyzed.

RESULTS

A total of 422 patients were diagnosed with DCIS. There were 400 patients treated with WLE, and 27 of these received adjuvant radiotherapy. The 5- and 8-year overall and breast cancer specific survival rates were 96.1 and 91.3%, and 99.6 and 99.3%, respectively. The local recurrence rate was 15.4 and 17.1% at 5 and 8 years. Of 56 local recurrences, 34 had WLE after recurrence, 16 of which had adjuvant radiotherapy. No single factor was statistically significantly associated with local recurrence, although combining factors revealed groups where the LR rate was less than 5%.

CONCLUSIONS

Breast cancer specific mortality was very low in this cohort of older patients with screen-detected DCIS. There was a moderate rate of local recurrence that could usually be salvaged with breast conservation. Decisions regarding adjuvant radiotherapy should take these findings into account.

Quantitative spectral reflectance imaging device for intraoperative breast tumor margin assessment

Diffuse reflectance spectroscopy of tissue allows quantification of underlying physiological and morphological changes associated with cancer, provided that the absorption and scattering properties of the tissue can be effectively decoupled. A particular application of interest for tissue reflectance spectroscopy in the UV-VIS is intraoperative detection of residual cancer at the margins of excised breast tumors, which could prevent costly and unnecessary repeat surgeries. Our multi-disciplinary group has developed an optical imaging device, which employs a model-based algorithm for quantification of tissue optical properties, and is capable of surveying the entire specimen surface down to a depth of 1-2 mm, all within a short time as required for intraoperative use. In an ongoing IRB-approved study, reflectance spectral images were acquired from 55 margins in 48 patients. Conversion of the spectral images to quantitative tissue parameter maps was facilitated by a fast scalable inverse Monte-Carlo model. Data from margin parameter images were reduced to image-descriptive scalar values and compared to gold-standard margin pathology. Use of a decision-tree based classification algorithm on the two most significant optical parameters resulted in a sensitivity of 79% and specificity of 67% for detection of residual tumor of all pathologic variants, with an 89% sensitivity for ductal carcinoma in situ alone. Preliminary data from this ongoing clinical study suggest that this technology could significantly reduce the number of unnecessary repeat breast conserving surgeries annually.

Rapid noninvasive optical imaging of tissue composition in breast tumor margins

BACKGROUND

In women undergoing breast conserving surgery (BCS), up to 60% can require re-excision. Our objective is to develop an optically based technology which can differentiate benign from malignant breast tissues intraoperatively through differences in tissue composition factors.

METHODS

A prospective study of optical imaging of BCS margins is being performed. Optical images are transformed into tissue composition maps with parameters of total hemoglobin concentration, b-carotene concentration and scattering. The predicted outcome is then compared to the margin-level pathology.

RESULTS

Fifty-five margins from 48 patients have undergone assessment. Within 34 specimens with pathologically confirmed positive margins, the ratio map of b-carotene/scattering showed the most significant difference reflecting a decrease in adipose and an increase in cell density within malignant margins (p=.002). These differences were notable in both in-situ and invasive disease.

CONCLUSIONS

We present a novel optical spectral imaging device that provides a rapid, non-destructive assay of the tissue composition of breast tumor margins.

Induction of acquired resistance to antiestrogen by reversible mitochondrial DNA depletion in breast cancer cell line

Although the net benefits of tamoxifen in adjuvant breast cancer therapy have been proven, the recurrence of the cancer in an aggressive and hormone independent form has been highly problematic. We previously demonstrated the important role mitochondrial DNA (mtDNA) plays in hormone-independence in prostate cancer. Here, the role of mtDNA in breast cancer progression was investigated. We established hydroxytamoxifen (4-OHT) resistant HTRMCF by growing MCF-7, human breast adenocarcinoma cells, in the presence of 4-OHT. HTRMCF was cross-resistant to 4-OHT and ICI182,780 concurrent with the depletion of mtDNA. To further investigate the role of mtDNA depletion, MCF-7 was depleted of mtDNA by treatment with ethidium bromide. MCF Rho 0 was resistant to both 4-OHT and ICI182,780. Furthermore, cybrid (MCFcyb) prepared by fusion MCF Rho 0 with platelet to transfer mtDNA showed susceptibility to antiestrogen. Surprisingly, after withdrawal of 4-OHT for 8 weeks, HTRMCF and their clones became susceptible to both drugs concurrent with a recovery of mtDNA. Herein, our results substantiated the first evidence that the depletion of mtDNA induced by hormone therapy triggers a shift to acquired resistance to hormone therapy in breast cancer. In addition, we showed that mtDNA depletion can be reversed, rendering the cancer cells susceptible to antiestrogen. The fact that the hormone independent phenotype can be reversed should be a step toward more effective treatments for estrogen-responsive breast cancer.

Overview of Adjuvant Systemic Therapy in Early Stage Breast Cancer

The benefits of adjuvant systemic therapy in reducing risk of distant relapse from breast cancer have been recognized for several decades. The intent of adjuvant therapy is to eliminate the occult micrometastatic breast cancer burden before it progresses into clinically apparent disease. Successful delivery of effective adjuvant systemic therapy as a complement to surgical management of breast cancer has contributed to the steady declines in breast cancer mortality observed internationally over the past 2 decades. Ongoing clinical and translational research in breast cancer seeks to improve the efficacy of systemic agents for use in the conventional postoperative (adjuvant) setting.

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.

Genetic bases of estrogen-induced tumorigenesis in the rat: mapping of loci controlling susceptibility to mammary cancer in a Brown Norway x ACI intercross

Exposure to estrogens is associated with an increased risk of breast cancer. Our laboratory has shown that the ACI rat is uniquely susceptible to 17beta-estradiol (E2)-induced mammary cancer. We previously mapped two loci, Emca1 and Emca2 (estrogen-induced mammary cancer), that act independently to determine susceptibility to E2-induced mammary cancer in crosses between the susceptible ACI rat strain and the genetically related, but resistant, Copenhagen (COP) rat strain. In this study, we evaluate susceptibility to E2-induced mammary cancer in a cross between the ACI strain and the unrelated Brown Norway (BN) rat strain. Whereas nearly 100% of the ACI rats developed mammary cancer when treated continuously with E2, BN rats did not develop palpable mammary cancer during the 196-day course of E2 treatment. Susceptibility to E2-induced mammary cancer segregated as a dominant or incompletely dominant trait in a cross between BN females and ACI males. In a population of 251 female (BN x ACI)F(2) rats, we observed evidence for a total of five genetic determinants of susceptibility. Two loci, Emca4 and Emca5, were identified when mammary cancer status at sacrifice was evaluated as the phenotype, and three additional loci, Emca6, Emca7, and Emca8, were identified when mammary cancer number was evaluated as the phenotype. A total of three genetic interactions were identified. These data indicate that susceptibility to E2-induced mammary cancer in the BN x ACI cross behaves as a complex trait controlled by at least five loci and multiple gene-gene interactions.

Breast biopsy and race/ethnicity among women without breast cancer

BACKGROUND

Breast biopsy is essential for definitive breast cancer diagnosis, but may also play a role in determining eligibility for breast cancer preventive measures or clinical trials. In addition, the prevalence of a history of negative breast biopsy can be viewed as an indicator of the adequacy or intensity of health care in a given population. We therefore analyzed the association of a history of breast biopsy with race/ethnicity and other factors in a cohort of women without a cancer diagnosis who completed a risk assessment form for participation in the Study of Tamoxifen and Raloxifene (STAR) and a sociodemographic questionnaire.

METHODS

Subjects were recruited at our large, urban teaching hospital. We developed a logistic regression model with biopsy (ever/never) as the outcome and age, race/ethnicity, educational attainment, and insurance coverage as the independent variables.

RESULTS

Among 805 unaffected predominantly minority subjects, white women were more than three times as likely as black and Hispanic women (OR=3.3, 95% CI 1.9-5.9), and insured women were twice as likely as uninsured women (OR=2.0, 95% CI 1.4-2.9) to have had a biopsy. Biopsy results were also associated with race/ethnicity.

DISCUSSION

We view these observations as hypothesis-generating rather than definitive. If confirmed, the associations we observed between negative biopsies and insurance status may reflect disparities in the timeliness and effectiveness of follow-up of suspicious lesions found via mammography. Our findings may also be relevant to the well-known association of breast cancer stage at diagnosis with low income and minority race/ethnicity.

Is BRCA1/BRCA2-related breast carcinogenesis estrogen dependent?

Estrogen is a well known promoting factor of sporadic breast carcinoma. With regard to hereditary breast carcinoma, such as in BRCA1/BRCA2 syndromes, to date, the effects of estrogens on risk modification are not clear. Several studies have shown that prophylactic oophorectomy may decrease the risk of breast carcinoma in BRCA1/BRCA2 mutation carriers. Moreover, adjuvant tamoxifen therapy for primary breast carcinoma appears to diminish the risk of a second breast malignancy in BRCA1 mutation carriers. Conversely, exogenous estrogens, such as oral contraceptives, may increase the risk of breast carcinoma in familial breast cancer, as suggested by clinical studies. Paradoxically, the majority of BRCA1-related breast carcinomas are negative for ER. There is some biologic evidence of interactions between estrogens and BRCA proteins. BRCA1 expression could be induced by estradiol in experimental models, whereas recent studies indicate that BRCA1 modifies the regulatory effects of the estrogen receptor (ER) alpha (ERalpha). Prospective studies will be required to estimate the potential benefits of estrogen suppression therapies for the prevention and adjuvant treatment of BRCA1/BRCA2-related breast carcinomas.

Barriers to minority participation in breast carcinoma prevention trials

BACKGROUND

Breast carcinoma prevention trials must recruit large cohorts of women who have an above-average risk of developing breast carcinoma. Recruitment for the Study of Tamoxifen and Raloxifene (STAR) trial required volunteers to complete a risk assessment questionnaire form (RAF). Women whose estimated risk of developing breast carcinoma in the next 5 years was > or = 1.67% based on the Gail model were invited to participate in STAR. Less than 4% of participants in the previously conducted P1 (tamoxifen vs. placebo) trial were minority women. We, therefore, studied barriers to minority participation in STAR among black, white, and Hispanic women who completed an RAF.

METHODS

The authors analyzed the association of Gail model risk factors, education, and insurance with race/ethnicity using chi-square tests and two-sided P values. They developed logistic regression models of trial eligibility, controlling for the Gail model risk factors, education, and insurance status.

RESULTS

Among 823 women who completed an RAF, white women were 10 times as likely as Hispanic women and 45 times as likely as black women to be eligible for STAR. Age at first birth (P = 0.04), having an affected first-degree relative (P < 0.0001), having had a biopsy (P < 0.0001), education (P < 0.0001), and insurance status (P < 0.0001) varied by race/ethnicity. All variables except insurance status were associated with eligibility when race was excluded from the model. In a model that included race/ethnicity, the same factors remained statistically significant.

CONCLUSIONS

These findings suggested that both the race/ethnicity adjustment and socioeconomic factors were barriers to eligibility for and contribute to low minority participation in breast cancer prevention trials.

Tamoxifen for breast cancer chemoprevention: low uptake by high-risk women after evaluation of a breast lump

PURPOSE

The Breast Cancer Prevention Trial (BCPT) published results in 1998 showing that the use of tamoxifen in high-risk women reduced the incidence of invasive breast cancer by 49%. We examined the clinical impact of the BCPT to determine whether high-risk women informed of these results would use tamoxifen for chemoprophylaxis and to investigate the factors influencing this decision.

METHODS

Of 345 women evaluated for a breast lump at a referral center, 89 were defined as high risk for but did not currently have cancer. These women were contacted about their elevated risk and informed that there exists a medication proved to reduce this risk. They were encouraged to discuss the issue with their family physician, to whom we sent copies of the 3 largest tamoxifen chemoprevention studies, including the BCPT. Follow-up was conducted by telephone to determine each woman's choice regarding tamoxifen use for chemoprevention and to ascertain her reasons for reaching this decision.

RESULTS

Of the 89 high-risk women, 1 decided to take tamoxifen for breast cancer chemoprevention. Only 48 women discussed tamoxifen with their family physician; in 3 cases (3.4%) the family physician recommended that the patient start taking tamoxifen, in 8 cases (9.1%) the family physician made no recommendations, and in 37 cases (42%) the family physician advised against tamoxifen. The most frequently cited factors influencing the decision not to start tamoxifen were a fear of adverse events (46.8%), the family physician's recommendation (31.9%), and a perceived low breast cancer risk (34%).

CONCLUSION

Family physicians recommended prophylactic tamoxifen to few women and even fewer women chose to take it. The major barrier appears to be concern about potential adverse effects of tamoxifen.

Treatment of axillary lymph node-negative, estrogen receptor-negative breast cancer: updated findings from National Surgical Adjuvant Breast and Bowel Project clinical trials

BACKGROUND

Results from three National Surgical Adjuvant Breast and Bowel Project sequentially conducted randomized trials of postoperative chemotherapy in women with estrogen receptor-negative tumors and negative axillary lymph nodes have demonstrated that a combination of methotrexate and 5-fluorouracil (MF) is more effective than surgery alone, that cyclophosphamide with MF (CMF) is more effective than MF, and that CMF and doxorubicin (Adriamycin) with cyclophosphamide (AC) are equally beneficial. This report presents updated findings from those trials, relates the results to age and menopausal status, and estimates the extent of progress made in treating such patients.

METHODS

Patients were randomly assigned as follows: in B-13, 760 patients were assigned to surgery only or to MF; in B-19, 1095 patients were assigned to MF or CMF; in B-23, 2008 patients were assigned to CMF or AC. Recurrence-free survival (RFS) and overall survival (OS) were estimated according to age and menopausal status. Smoothed recurrence rates were used to evaluate patterns of recurrence as a continuous function of age. The Cox proportional hazards model was used to test for interactions between treatment and covariates and to estimate hazard ratios (HRs) for pairwise group comparisons.

RESULTS

In B-13, through 16 years of follow-up, an overall benefit was seen with MF relative to surgery alone (RFS: HR = 0.59, 95% confidence interval [CI] = 0.44 to 0.78, P<0.001; OS: HR = 0.75, 95% CI = 0.58 to 0.98, P = 0.03). In B-19, through 13 years of follow-up, an overall benefit was seen for CMF relative to MF (RFS: HR = 0.59, 95% CI = 0.45 to 0.77, P<0.001; OS: HR = 0.71; 95% CI = 0.55 to 0.92; P = 0.01). In both trials, all age and menopausal groups demonstrated an RFS benefit, and most demonstrated an OS benefit. In B-23, through 8 years of follow-up, there were no statistically significant differences between the CMF and AC groups (RFS: HR = 1.00, 95% CI = 0.79 to 1.27, P = 0.97; OS, HR = 0.92, 95% CI = 0.73 to 1.17; P = 0.51). When women in the CMF or AC groups (B-19, B-23) were compared with those who were in the surgery-alone group (B-13), through 8 years of follow-up there was a 58% reduction in recurrence and a 40% reduction in mortality as a result of the chemotherapy.

CONCLUSIONS

Outcomes in CMF- or AC-treated women with estrogen receptor-negative tumors and negative axillary lymph nodes were similar in all age groups. The decreased benefit from chemotherapy observed with increasing age was a result of a better outcome associated with advancing age in women who underwent surgery alone rather than a poorer outcome resulting from the use of chemotherapy.

Lack of Effect of Celecoxib on Prostaglandin E2 Concentrations in Nipple Aspirate Fluid from Women at Increased Risk of Breast Cancer

Background: Cyclooxygenase enzymes (COX-1, COX-2, and COX-3) convert arachidonic acid to prostaglandins, prostacyclins, thromboxanes, and other hydroxy fatty acids. Among these, prostaglandin E2 (PGE2) has tumor growth-promoting activity. The COX-2 isoform is the primary enzyme involved in PGE2 production in cancerous tissue.

Objective/Hypothesis: We administered the COX-2 inhibitor celecoxib (200 mg b.i.d.) to women at increased breast cancer risk. Our hypothesis was that PGE2 would be secreted in breast nipple aspirate fluid (NAF), that levels in NAF would be higher than in corresponding plasma, and that celecoxib would decrease PGE2 levels in NAF (reflecting a decreased breast tissue eicosanoid production) and plasma.

Specific Aim: To determine if PGE2 concentrations in NAF and plasma decrease after a 2-week course of celecoxib and then return to baseline 2 weeks after stopping the medication (washout).

Study Design: NAF and plasma were collected before celecoxib treatment, 2 weeks after taking celecoxib, and 2 weeks after washout. Each woman served as her own control.

Results: PGE2 concentrations in NAF and plasma were detectable in samples using two measurement techniques. On average, NAF PGE2 levels were 81-fold higher in NAF than in matched plasma. Technically, there were differences in PGE2 concentrations measured in similar fluids depending on the assay technique used (RIA versus chemiluminescence immunoassay). There were no significant decreases in PGE2 concentrations after celecoxib administration.

Conclusions: PGE2 can be measured in NAF. PGE2 levels are concentrated in NAF when compared with matched plasma samples. Celecoxib 200 mg b.i.d. does not appear to significantly decrease PGE2 concentrations in NAF and plasma.

Axillary recurrence after sentinel lymph node biopsy

Sentinel lymph node biopsy (SLNB) without further axillary dissection in patients with sentinel node-negative breast carcinoma appears to be a safe procedure to ensure locoregional control. During a median follow-up of 35 months the false-negative rate was 1% in our study population of 185 patients.

BACKGROUND

The objective of this prospective study is to provide data on follow-up of patients with primary operable breast carcinoma staged with SLNB without axillary lymph node dissection (ALND) if the sentinel lymph nodes (SLNs) were tumour-negative.

METHODS

One hundred and eighty-five patients were enrolled. Preoperative dynamic and static lymphoscintigraphy were performed; both a vital blue dye and a gamma detection probe were used intraoperatively. Patients with tumour-positive SLNs received completion ALND or if no SLNs could be identified. All patients were monitored according to regional follow-up protocols.

RESULTS

The SLNs were identified in 179 out of the 185 patients. In 73 patients the SLNs were tumour-positive and in 106 patients tumour-negative. The median follow-up was 35 months (range 17-59). In one SLN-negative patient an axillary recurrence occurred 26 months after the SLNB (false-negative rate: 1%).

CONCLUSIONS

SLNB without ALND appears to be a safe procedure to ensure locoregional control in SLN-negative breast carcinoma, if carried out by an experienced team.

Primary small bowel carcinoid tumor with bilateral breast metastases: report of 2 cases with different clinical presentations

CONTEXT

Carcinoid tumor metastatic to the breast is uncommon and can closely mimic a mammary carcinoma. The differentiation of metastatic carcinoid tumor from primary breast tumor is important, however, owing to different clinical management and prognosis.

OBJECTIVE

The purpose of this study was to describe 2 patients with bilateral metastatic carcinoid tumors to the breast with different clinical manifestations.

DESIGN

We examined the radiological, clinical, cytologic, histologic, immunohistochemical, and ultrastructural features of these 2 cases.

RESULTS

In case 1, the tumor presented initially as a stellate mass on mammogram and was diagnosed as grade II infiltrating ductal carcinoma. It was only after the discovery of small intestinal, liver, ovarian, and contralateral breast masses, as well as careful morphologic and immunohistochemical evaluations, that the true nature of the tumor was realized. In case 2, the tumor initially presented as a small intestinal tumor with liver metastases and bilateral breast masses. The breast masses were diagnosed accurately as metastatic carcinoid tumor by morphologic and immunohistochemical evaluations.

CONCLUSIONS

Metastatic carcinoid tumor to the breast is uncommon, but poses a diagnostic challenge in that morphologically it can closely mimic a primary breast tumor. Careful attention to clinical features and the use of auxiliary immunohistochemical studies can help in arriving at the correct diagnosis.

Population-based assessment of hospitalizations for toxicity from chemotherapy in older women with breast cancer

PURPOSE

There are no population-based data on hospitalization rate for toxicity from breast cancer chemotherapy, and even large clinical trials often do not report this information. Medicare data, linked to the Surveillance, Epidemiology, and End-Results (SEER) tumor registries, are now used to assess rates of hospitalization for chemotherapy-related toxicity in a population-based setting.

PATIENTS AND METHODS

A total of 35,060 women diagnosed with stages I through IV breast cancer aged >or= 65 from 1991 through 1996 were identified from the SEER-Medicare linked program and studied. Patients were defined as being hospitalized for adverse effects of chemotherapy if there was a Medicare inpatient claim for neutropenia, fever, thrombocytopenia, or adverse effect of systemic therapy less than 7 months after diagnosis of breast cancer.

RESULTS

More than 9% of women with breast cancer who received chemotherapy were admitted with the diagnosis of neutropenia, fever, thrombocytopenia, or adverse effect of systemic therapy, compared with 0.5% of women with breast cancer who did not receive chemotherapy. The rates for stage I to IV were 6.3%, 8.1%, 12.3%, and 13.2% in those treated with chemotherapy, and 0.4%, 0.6%, 0.7%, and 1.5% in women not treated with chemotherapy. The hospitalization rates for adverse effects increased significantly with comorbidity score and varied more than two-fold across the nine SEER areas but did not vary by age. Use of anthracycline-containing chemotherapy agents was associated with greater odds of these toxicities (eg, odds ratio, 2.53 for neutropenia; 95% confidence interval, 1.97 to 3.26).

CONCLUSION

This study demonstrated the feasibility of using Medicare data to assess rates of hospitalization for serious toxicity associated with cancer chemotherapy. Rates in actual practice were higher than those reported in clinical trials and did not vary by age.

Increase of chemotherapy use in older women with breast carcinoma from 1991 to 1996

BACKGROUND

There is little population-based information available on the actual use of chemotherapy and how closely this use mirrors consensus recommendations. The authors hypothesized that given the relative stability of consensus conference recommendations on chemotherapy use during the period 1991-1996 the patterns of use would more closely approximate consensus recommendation over time.

METHODS

The authors studied women who received a diagnosis of Stage I-IV (American Joint Committee on Cancer staging) breast carcinoma at age 65 years and older from 1991 through 1996, using the SEER cancer registry cases linked with Medicare claims.

RESULTS

Overall, women whose disease was diagnosed in 1996 had a 30% higher chance of receiving chemotherapy than those in 1991, after controlling for changes in tumor size, stage, and other factors. The use of chemotherapy was strongly influenced by age, with women age 65-69 years more than twice as likely to receive it as were women 70 years and older. The increase over time in chemotherapy depended on both tumor stage and patient age. For Stage I tumor, there was no increase in chemotherapy for any age. For Stage II, the increase was limited to younger women, whereas for Stage III and IV it was observed in women age 70 years and older.

CONCLUSIONS

There was a significant increase of chemotherapy use over time from 1991 to 1996 in women age 65 years and older with breast carcinoma. The increase was limited to younger women and those with advanced stage at diagnosis. Thus, consensus recommendations and community practice seemed to mirror each other over time.

Design considerations for efficient prostate cancer chemoprevention trials

Prostate cancer, even with its substantial public health impact of 180,400 new cases and 31,900 deaths estimated for 2000, still has a very low annual incidence (0.27% for men 34.4 years and older), which makes designing and conducting efficient prostate cancer prevention trials a challenge. Definitive prevention trials with cancer endpoints, such as the Breast Cancer Prevention Trial (BCPT), Prostate Cancer Prevention Trial (PCPT), and Selenium and Vitamin E Cancer Prevention Trial (SELECT), require long trial duration (up to 12 years) and large sample size (up to 32,400 subjects) to accomplish their objectives. This article discusses design concepts for potential prostate cancer prevention trials that require fewer years, subjects, and resources to complete. Design elements, such as high-risk populations, randomization, surrogate endpoints, including quality-of-life endpoints, masking/blinding, and various clinical/statistical designs (including 1-way layout, all-versus-none, factorial, and adaptive designs), are discussed, along with the ultimate goal of gaining US Food and Drug Administration approval for prostate-cancer preventive agents that can improve public health by reducing prostate cancer incidence and mortality.

Expression of the hypoxia-inducible and tumor-associated carbonic anhydrases in ductal carcinoma in situ of the breast

Carbonic anhydrases (CA) influence intra- and extracellular pH and ion transport in varied biological processes. We recently identified CA9 and CA12 as hypoxia-inducible genes. In this study we examined the expression of these tumor-associated CAs by immunohistochemistry in relation to necrosis and early breast tumor progression in 68 cases of ductal carcinoma in situ (DCIS) (39 pure DCIS and 29 DCIS associated with invasive carcinoma). CA IX expression was rare in normal epithelium and benign lesions, but was present focally in DCIS (50% of cases) and in associated invasive carcinomas (29%). In comparison, CA XII was frequently expressed in normal breast tissues (89%), in DCIS (84%), and in invasive breast lesions (71%). In DCIS, CA IX was associated with necrosis (P: = 0.0053) and high grade (P: = 0.012). In contrast, CA XII was associated with the absence of necrosis (P: = 0.036) and low grade (P: = 0.012). Despite this, augmented CA XII expression was occasionally observed adjacent to necrosis within high-grade lesions. Neither CA IX nor CA XII expression was associated with regional or overall proliferation as determined by MIB1 staining. Assessment of mammographic calcification showed that CA XII expression was associated with the absence of calcification (n = 43, P: = 0.0083). Our results demonstrate that induction of CA IX and CA XII occurs in regions adjacent to necrosis in DCIS. Furthermore, these data suggest that proliferation status does not influence expression of either CA in breast tissues, that hypoxia may be a dominant factor in the regulation of CA IX, and that factors related to differentiation, as determined by tumor grade, dominate the regulation of CA XII. The existence of differential regulation and associations with an aggressive phenotype may be important in the development of selective inhibitors of CAs, because the latter have recently been shown to prevent tumor invasion.

Impact of chemotherapy dose-density on radiotherapy dose-intensity after breast conserving surgery

PURPOSE

To evaluate if chemotherapy (CT) dose-intensification jeopardizes radiotherapy (RT) dose-intensity (DI).

PATIENTS AND METHODS

From 1992 to 1997, 247 stage I-II breast cancer patients, treated with conserving surgery, were treated at the National Cancer Institute of Genoa in a randomized study comparing the same CEF regimen delivered every two weeks (CEF14) or three weeks (CEF21). RT was applied to the residual breast at a total dose of 50 Gy in five weeks. Allowance was made for treatment at 2.3 Gy per fraction in order to compensate for gaps (hypofractionation). Radiotherapy DI was expressed as the average total dose received each week, i.e., 'weekly dose-rate' (WDR). The effect of various tumour, treatment and patient-related factors on the endpoint (a delivered WDR of RT < 9.5 Gy) was investigated by univariate analysis. Factors found to have P-value < or = 0.20 were entered in multivariate analysis.

RESULTS

All but three patients (244 of 247, 98.8%) received a cumulative total dose of RT within +/- 10% of that planned. Moreover, most of them (197 of 247, 79.8%) received an average WDR of > or = 9.5 Gy/wk. With univariate analysis the probability of WDR < 9.5 Gy/wk significantly correlated with age, menopausal status, concomitant administration of RT and CT, and white blood cell toxicity. Moreover, a positive effect on WDR was found in patients treated at 2.3 Gy per fraction. The type of treatment (CEF14 vs. CEF21) did not affect the probability of WDR < 9.5 Gy/wk. With multivariate analysis, age (< or = 55 vs. > 55 years, RR = 3.99, 95% CI: 1.89-8.42, P = 0.0003), RT fractionation (conventional vs. hypofractionation, RR = 0.32, 95% CI: 0.15-0.68, P = 0.017) and WBC toxicity (none vs. some, RR = 1.54, 95% CI: 1.06-2.22, P = 0.027) were independent predictors of WDR < 9.5 Gy. Regarding the CT-RT overlap, patients receiving more than two cycles of chemotherapy during radiotherapy had an increased risk of RT delay compared to other patients (RR = 3.74, 95% CI: 1.44-9.48, P = 0.0063).

CONCLUSIONS

There is no evidence of a direct effect of CT dose-density on dose-intensity of RT. However, the concomitant use of CT and RT reduces the possibility of giving a full dose-intensity of RT.

Biologic and clinical significance of lymphadenectomy

Interest in the lymphatic system and its relationship to metastases has developed owing to renewed interest in sentinel node biopsy. This article summarizes the anatomy, physiology, and biology of the lymphatic system and lymph node metastases, and reviews studies of lymph node metastases and surgical resection of cancers in different anatomic sites. On the basis of these studies, the authors conclude that lymph node metastasis functions as an indicator of prognosis, not the controlling or determining factor of prognosis. Thus, varying degrees of treatment of regional lymph nodes and metastases do not seem to be controlling factors in the outcome of cancer.

Systemic therapy

Our knowledge base on systemic therapy for breast cancer continues to expand, including further information regarding hormonal prevention in high-risk women, beneficial effects of tamoxifen in noninvasive disease, an update on primary systemic therapy, and optimization of adjuvant strategies, including data on adjuvant chemoendocrine regimens. The proper evaluation of high-dose strategies has been jeopardized by a serious episode of scientific misconduct. New data are also available on palliative options, bisphosphonates, antibody therapies, and novel targets. Data continue to evolve on the role and optimal schedules of taxanes in early-stage and advanced breast cancer. These and other important recent findings are discussed in this review article.