Chemotherapy is more effective in patients with breast cancer not expressing steroid hormone receptors: a study of preoperative treatment

Estrogen-receptor status and outcomes of modern chemotherapy for patients with node-positive breast cancer

CONTEXT

Breast cancer estrogen-receptor (ER) status is useful in predicting benefit from endocrine therapy. It may also help predict which patients benefit from advances in adjuvant chemotherapy.

OBJECTIVE

To compare differences in benefits from adjuvant chemotherapy achieved by patients with ER-negative vs ER-positive tumors.

DESIGN, SETTING, AND PATIENTS

Trial data from the Cancer and Leukemia Group B and US Breast Cancer Intergroup analyzed; patient outcomes by ER status compared using hazards over time and multivariate models. Randomized trials comparing (1): 3 regimens of cyclophosphamide, doxorubicin, and fluorouracil (January 1985 to April 1991); (2) 3 doses of doxorubicin concurrent with cyclophosphamide, with or without subsequent paclitaxel (May 1994 to April 1997); (3) sequential doxorubicin, paclitaxel, and cyclophosphamide with concurrent doxorubicin and cyclophosphamide followed by paclitaxel, and also 3-week vs 2-week cycles (September 1997 to March 1999). A total of 6644 node-positive breast cancer patients received adjuvant treatment.

MAIN OUTCOME MEASURES

Disease-free and overall survival.

RESULTS

For ER-negative tumors, chemotherapy improvements reduced the relative risk of recurrence by 21%, 25%, and 23% in the 3 studies, respectively, and 55% comparing the lowest dose in the first study with biweekly cycles in the third study. Corresponding relative risk reductions for ER-positive tumors treated with tamoxifen were 9%, 12%, and 8% in the 3 studies, and 26% overall. The overall mortality rate reductions associated with chemotherapy improvements were 55% and 23% among ER-negative and ER-positive patients, respectively. All individual ER-negative comparisons and no ER-positive comparisons were statistically significant. Absolute benefits due to chemotherapy were greater for patients with ER-negative compared with ER-positive tumors: 22.8% more ER-negative patients survived to 5 years disease-free if receiving chemotherapy vs 7.0% for ER-positive patients; corresponding improvements for overall survival were 16.7% vs 4.0%.

CONCLUSION

Among patients with node-positive tumors, ER-negative breast cancer, biweekly doxorubicin/cyclophosphamide plus paclitaxel lowers the rate of recurrence and death by more than 50% in comparison with low-dose cyclophosphamide, doxorubicin, and fluorouracil as used in the first study.

Sequential preoperative or postoperative docetaxel added to preoperative doxorubicin plus cyclophosphamide for operable breast cancer:National Surgical Adjuvant Breast and Bowel Project Protocol B-27

PURPOSE

This study was designed to determine the effect of adding docetaxel (T) to preoperative doxorubicin and cyclophosphamide (AC) on breast cancer response rates and disease-free survival (DFS) and overall survival (OS).

PATIENTS AND METHODS

Women with operable breast cancer (N = 2,411) were randomly assigned to receive preoperative AC followed by surgery, AC followed by T and surgery, or AC followed by surgery and then T. Tamoxifen was initiated concurrently with chemotherapy. Median time on study for 2,404 patients with follow-up was 77.9 months.

RESULTS

Addition of T to AC did not significantly impact DFS or OS. There were trends toward improved DFS with addition of T. The addition of T reduced the incidence of local recurrences as first events (P = .0034). Preoperative T, but not postoperative T, significantly improved DFS in patients who had a clinical partial response after AC (hazard ratio [HR] = 0.71; 95% CI, 0.55 to 0.91; P = .007). Pathologic complete response, which was doubled by addition of preoperative T, was a significant predictor of OS regardless of treatment (HR = 0.33; 95% CI, 0.23 to 0.47; P < .0001). Pathologic nodal status after chemotherapy was a significant predictor of OS (P < .0001).

CONCLUSION

The addition of preoperative or postoperative T after preoperative AC did not significantly affect OS, slightly improved DFS, and decreased the incidence of local recurrences. The sample size of this study was not sufficient to yield significance for the moderate DFS improvement. Concurrent use of tamoxifen may have limited the impact of adding T.

Application of DNA microarray technology in determining breast cancer prognosis and therapeutic response

There are > 1.15 million cases of breast cancer diagnosed worldwide annually, and it is the second leading cause of cancer death in the European Union. The optimum management of patients with breast cancer requires accurate prognostic and predictive factors. At present, only a small number of such factors are used clinically. DNA microarrays have the potential to measure the expression of tens of thousands of genes simultaneously. Recent preliminary findings suggest that DNA microarray-based gene expression profiling can provide powerful and independent prognostic information in patients with newly diagnosed breast cancer. As well as providing prognostic information, emerging results suggest that DNA microarrays can also be used for predicting response or resistance to treatment, especially to neoadjuvant chemotherapy. Prior to clinical application, these preliminary findings must be validated using large-scale prospective studies. This article reviews these advances and also examines the role of DNA microarrays in reducing the number of patients who receive inappropriate chemotherapy. The most recent data supporting the integration of various publicly available data sets is also reviewed in detail.

Prognostic value of pathologic complete response after primary chemotherapy in relation to hormone receptor status and other factors

PURPOSE

To evaluate whether hormonal receptor (HR) status can influence the prognostic significance of pathologic complete response (pCR).

PATIENTS AND METHODS

This retrospective analysis included 1,731 patients with stage I to III noninflammatory breast cancer treated between 1988 and 2005 with primary chemotherapy (PC). Ninety-one percent of patients received anthracycline-based PC, and 66% received additional taxane therapy. pCR was defined as no evidence of invasive tumor in the breast and axillary lymph nodes.

RESULTS

Median age was 49 years (range, 19 to 83 years). Sixty-seven percent of patients (n = 1,163) had HR-positive tumors. A pCR was observed in 225 (13%) of 1,731 patients; pCR rates were 24% in HR-negative tumors and 8% in HR-positive tumors (P < .001). A significant survival benefit for patients who achieved pCR compared with no pCR was observed regardless of HR status. In the HR-positive group, 5-year overall survival (OS) rates were 96.4% v 84.5% (P = .04) and 5-year progression-free survival (PFS) rates were 91.1% v 65.3% (P < .0001) for patients with and without pCR, respectively. For the HR-negative group, 5-year OS rates were 83.9% v 67.4% (P = .003) and 5-year PFS rates were 83.4% v 50.0% (P < .0001) for patients with and without pCR, respectively. After adjustment for adjuvant hormonal treatment, HR status, clinical stage, and nuclear grade, patients who achieved a pCR had 0.36 times the risk of death.

CONCLUSION

pCR is associated with better outcome regardless of HR status in breast cancer patients who receive PC.

Metronomic low-dose oral cyclophosphamide and methotrexate plus or minus thalidomide in metastatic breast cancer: antitumor activity and biological effects

BACKGROUND

We previously demonstrated efficacy and impact on serum vascular endothelial growth factor (VEGF) for metronomic cyclophosphamide (C) and methotrexate (M) in patients with breast cancer. New metronomic schedules were investigated.

PATIENTS AND METHODS

Patients with advanced breast cancer were randomized to receive oral C (50 mg daily) and M (2.5 mg twice daily on days 1 and 4) (arm A) or the same regimen plus thalidomide (200 mg daily) (arm B).

RESULTS

The mean VEGF level decreased from 378.9 (+/-274.4) pg/ml at baseline to 305.9 (+/-203.6) pg/ml at 2 months (P<0.001), with similar change with respect to baseline in both arms. In 171 evaluable patients we observed three complete remissions (CR) in both arms A and B, 15 partial remission (PR) in arm A and seven in arm B, for an overall response of 20.9% [95% confidence interval (CI) 12.9% to 31%] in arm A and 11.8% (95% CI 5.8% to 20.6%) in arm B. The clinical benefit (CR+PR+SD>or=24 weeks) was 41.5% for both arms. Toxicity was generally mild. Higher neurological toxicity (2% versus 60%; P<0.0001) and constipation (8% versus 51%; P<0.0001) was observed in arm B.

CONCLUSIONS

Metronomic low-dose CM induced a drop in VEGF, and was effective and minimally toxic. The addition of thalidomide did not improve results.

Concepts and clinical trials of dose-dense chemotherapy for breast cancer

This article will review the strategy of dose-dense administration of chemotherapy for breast cancer. Increased dose density is achieved by reducing the interval between each dose of chemotherapy. The cumulative drug dose remains constant, but the same amount of drug is administered over a shorter period. Mathematical models of tumor growth have provided the basis for the clinical application of dose-dense chemotherapy. The Norton-Simon model suggests that increasing the dose density of chemotherapy will increase efficacy by minimizing the opportunity for regrowth of tumor cells between cycles of chemotherapy. Intergroup trial 9741, coordinated by the Cancer and Leukemia Group B (CALGB), tested the 2 hypotheses that dose-dense and sequential administration of chemotherapy regimens incorporating doxorubicin, cyclophosphamide, and paclitaxel would improve disease-free survival and overall survival. A statistically significant 4-year disease-free survival advantage was detected for the 2 dose-dense regimens compared with the regimens administered every 3 weeks. The mathematical concepts and previous clinical trials of dose density that contributed to the design of CALGB 9741 will be reviewed. The strengths and limitations of CALGB 9741 will then be discussed before the presentation of future directions of research and recommendations for clinical practice today.

Ipsilateral breast tumor reappearance in patients treated with conservative surgery after primary chemotherapy. The role of surgical margins on outcome

BACKGROUND AND OBJECTIVES

To evaluate the ipsilateral breast tumor reappearance (IBTR) rate after breast conservative surgery (BCS) following primary chemotherapy (PC) and to assess whether positive margins affects IBTR rate and overall survival (OS).

METHODS

Three hundred nine women candidates for mastectomy received PC before surgery. One hundred ninety-five patients (63.1%) underwent BCS and 114 patients (36.9%) a modified radical mastectomy.

RESULTS

After a median follow-up of 41 months (range 7-90), 13 patients of the 195 treated with BCS had an IBTR (6.7%), 6 patients had a regional relapse (3.1%), 28 women had distant metastases (14.4%). Twenty-three patients died of breast cancer (11.8%). Twenty-four patients treated with BCS had positive margins (12.3%). At 3 years, the crude cumulative incidence of local recurrence was 4.7% in women with negative margins, and 13.3% in women with positive margins (P=0.05). Cumulative incidence of distant metastases was similar in patients with positive and negative margins (P=0.16) and there was no significant difference in terms of OS according to the margin status (P=0.577).

CONCLUSIONS

BCS after PC has an acceptable rate of IBTR. After a short follow-up, the presence of positive margins does not affect OS.

Adjuvant chemotherapy in 2005: Standards and beyond

The 2003 St. Gallen consensus panel divided the many available adjuvant chemotherapy (CT) regimens into those with "standard efficacy" (ACx4, CMFx6) and those with "superior efficacy" (FA(E)Cx6, CA(E)Fx6, A(E)-->CMF, TACx6, ACx4--> paclitaxel (P)x4 or docetaxel (D)x4) but also greater complexity, toxicity and cost. This paper will summarize the latest information on long-term side effects of the "superior" regimens and 5-year benefits reported in taxane trials, including those of a "new" sequential regimen, FECx3--> docetaxelx3. Rapidly expanding evidence of marked heterogeneity in the magnitude of CT benefits according to the tumour oestrogen receptor (ER) status, a claim made for many years by IBCSG investigators, will be reviewed; it will lead to the conclusion that a revolution needs to take place in the way oncologists think about the CT added value and design adjuvant clinical trials. The conclusions proposed to the 2005 St. Gallen consensus panel are that: adequately dosed anthracycline-based CT regimens remain an acceptable standard for many women; a lower threshold for using taxanes in sequence or combination with anthracyclines (A) is justified in the presence of an ER-negative or low-ER tumour status, other aggressive biologic features (such as HER-2 overexpression), fear about A-induced cardiotoxicity; no recommendation can yet be made as far as the optimal taxane-A regimen, the best taxane or the best taxane schedule.

Meeting Highlights: International Expert Consensus on the Primary Therapy of Early Breast Cancer 2005

The ninth St Gallen (Switzerland) expert consensus meeting in January 2005 made a fundamental change in the algorithm for selection of adjuvant systemic therapy for early breast cancer. Rather than the earlier approach commencing with risk assessment, the Panel affirmed that the first consideration was endocrine responsiveness. Three categories were acknowledged: endocrine responsive, endocrine non-responsive and tumors of uncertain endocrine responsiveness. The three categories were further divided according to menopausal status. Only then did the Panel divide patients into low-, intermediate- and high-risk categories. It agreed that axillary lymph node involvement did not automatically define high risk. Intermediate risk included both node-negative disease (if some features of the primary tumor indicated elevated risk) and patients with one to three involved lymph nodes without additional high-risk features such as HER 2/neu gene overexpression. The Panel recommended that patients be offered chemotherapy for endocrine non-responsive disease; endocrine therapy as the primary therapy for endocrine responsive disease, adding chemotherapy for some intermediate- and all high-risk groups in this category; and both chemotherapy and endocrine therapy for all patients in the uncertain endocrine response category except those in the low-risk group.

Predictors of primary breast cancers responsiveness to preoperative epirubicin/cyclophosphamide-based chemotherapy: translation of microarray data into clinically useful predictive signatures

Background

Our goal was to identify gene signatures predictive of response to preoperative systemic chemotherapy (PST) with epirubicin/cyclophosphamide (EC) in patients with primary breast cancer.

Methods

Needle biopsies were obtained pre-treatment from 83 patients with breast cancer and mRNA was profiled on Affymetrix HG-U133A arrays. Response ranged from pathologically confirmed complete remission (pCR), to partial remission (PR), to stable or progressive disease, "No Change" (NC). A primary analysis was performed in breast tissue samples from 56 patients and 5 normal healthy individuals as a training cohort for predictive marker identification. Gene signatures identifying individuals most likely to respond completely to PST-EC were extracted by combining several statistical methods and filtering criteria. In order to optimize prediction of non responding tumors Student's t-test and Wilcoxon test were also applied. An independent cohort of 27 patients was used to challenge the predictive signatures. A k-Nearest neighbor algorithm as well as two independent linear partial least squares determinant analysis (PLS-DA) models based on the training cohort were selected for classification of the test samples. The average specificity of these predictions was greater than 74% for pCR, 100% for PR and greater than 62% for NC. All three classification models could identify all pCR cases.

Results

The differential expression of 59 genes in the training and the test cohort demonstrated capability to predict response to PST-EC treatment. Based on the training cohort a classifier was constructed following a decision tree.

First, a transcriptional profile capable to distinguish cancerous from normal tissue was identified. Then, a "favorable outcome signature" (31 genes) and a "poor outcome signature" (26 genes) were extracted from the cancer specific signatures. This stepwise implementation could predict pCR and distinguish between NC and PR in a subsequent set of patients. Both PLS-DA models were implemented to discriminate all three response classes in one step.

Conclusion

In this study signatures were identified capable to predict clinical outcome in an independent set of primary breast cancer patients undergoing PST-EC.

Breast cancer recurrence dynamics following adjuvant CMF is consistent with tumor dormancy and mastectomy-driven acceleration of the metastatic process

PURPOSE

The aim of this study was to better understand human breast cancer biology by studying how the timing of metastasis following primary resection is affected by adjuvant CMF (cyclophoshamide, methotrexate, 5-fluorouracil) chemotherapy.

PATIENTS AND METHODS

Discrete hazards of recurrence and recurrence risk reductions for treated patients relative to controls were analyzed for all patients enrolled in two separate randomized clinical trials [study 1 (386 women): no further treatment versus 12 cycles of CMF; study 2 (459 women): six versus 12 cycles of CMF] and a historical group (396 women: surgery alone) of axillary node-positive patients undergoing mastectomy.

RESULTS

(i) Nearly all CMF benefit occurs during the first 4 years following resection/chemotherapy. (ii) The CMF recurrence rate reduction is largely restricted to two specific spans. These temporally separate recurrence clusters occur during the first and third year of follow-up, while the second-year recurrences are weakly affected. (iii) Prolonging adjuvant treatment from 6 to 12 months partially alters this recurrence timing, without appreciably affecting the overall recurrence rate. (iv) These effects upon the dynamics of post-resection occurrence are menopausal status-independent.

CONCLUSIONS

At least two different therapeutically vulnerable proliferative events, resulting in clinical appearance of two metastasis temporally distinct clusters of post-resection cancer recurrence, apparently occur during the administration of adjuvant chemotherapy. Metastases that transpire outside of these temporal windows are refractory to adjuvant therapy. The dynamics of both post-treatment recurrence risk and CMF effectiveness are similar for both pre- and postmenopausal women, suggesting that post-resection mechanisms by which chemotherapy prevents metastases are similar, but of different magnitude in pre- and postmenopausal women. These findings are consistent with a metastasis model that includes tumor dormancy in specific micrometastatic phases (single cells and avascular foci) and with the acceleration of the metastatic process by the surgical resection of the primary breast cancer.

Breast cancer

Breast cancer remains a public-health issue on a global scale. We report new information about the disease from the past 5 years. Early age at first birth, increasing parity, and tamoxifen use are related to long-term lifetime reduction in breast-cancer risk. Ductal carcinomas in situ has been suggested to be renamed ductal intraepithelial neoplasia to emphasise its non-life-threatening nature. An alternative approach, the progenitor/stem cell theory, predicts that only some tumour cells cause cancer progression and that these should be targeted by treatment. Mammography and ultrasonography are still the most effective for women with non-dense and dense breast tissues, respectively. Additionally, MRI, lymphatic mapping, the nipple-sparing mastectomy, partial breast irradiation, neoadjuvant systemic therapy, and adjuvant treatments are promising for subgroups of breast-cancer patients. Although tamoxifen can be offered for endocrine-responsive disease, aromatase inhibitors are increasingly used. Assessment of potential molecular targets is now important in primary diagnosis. Tyrosine-kinase inhibitors and other drugs with anti-angiogenesis properties are currently undergoing preclinical investigations.