Effect of preoperative chemotherapy on the outcome of women with operable breast cancer.

PURPOSE: To determine, in women with primary operable breast cancer, if preoperative doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan; AC) therapy yields a better outcome than postoperative AC therapy, if a relationship exists between outcome and tumor response to preoperative chemotherapy, and if such therapy results in the performance of more lumpectomies. PATIENTS AND METHODS: Women (1,523) enrolled onto National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 were randomly assigned to preoperative or postoperative AC therapy. Clinical tumor response to preoperative therapy was graded as complete (cCR), partial (cPR), or no response (cNR). Tumors with a cCR were further categorized as either pathologic complete response (pCR) or invasive cells (pINV). Disease-free survival (DFS), distant disease-free survival (DDFS), and survival were estimated through 5 years and compared between treatment groups. In the preoperative arm, proportional-hazards models were used to investigate the relationship between outcome and tumor response. RESULTS: There was no significant difference in DFS, DDFS, or survival (P = .99, .70, and .83, respectively) among patients in either group. More patients treated preoperatively than postoperatively underwent lumpectomy and radiation therapy (67.8% v 59.8%, respectively). Rates of ipsilateral breast tumor recurrence (IBTR) after lumpectomy were similar in both groups (7.9% and 5.8%, respectively; P = .23). Outcome was better in women whose tumors showed a pCR than in those with a pINV, cPR, or cNR (relapse-free survival [RFS] rates, 85.7%, 76.9%, 68.1%, and 63.9%, respectively; P < .0001), even when baseline prognostic variables were controlled. When prognostic models were compared for each treatment group, the preoperative model, which included breast tumor response as a variable, discriminated outcome among patients to about the same degree as the postoperative model. CONCLUSION: Preoperative chemotherapy is as effective as postoperative chemotherapy, permits more lumpectomies, is appropriate for the treatment of certain patients with stages I and II disease, and can be used to study breast cancer biology. Tumor response to preoperative chemotherapy correlates with outcome and could be a surrogate for evaluating the effect of chemotherapy on micrometastases; however, knowledge of such a response provided little prognostic information beyond that which resulted from postoperative therapy.

Adjuvant T-DM1 versus trastuzumab in patients with residual invasive disease after neoadjuvant therapy for HER2-positive breast cancer: subgroup analyses from KATHERINE.

BACKGROUND: In the KATHERINE study (NCT01772472), patients with residual invasive early breast cancer (EBC) after neoadjuvant chemotherapy (NACT) plus human epidermal growth factor receptor 2 (HER2)-targeted therapy had a 50% reduction in risk of recurrence or death with adjuvant trastuzumab emtansine (T-DM1) versus trastuzumab. Here, we present additional exploratory safety and efficacy analyses. PATIENTS AND METHODS: KATHERINE enrolled HER2-positive EBC patients with residual invasive disease in the breast/axilla at surgery after NACT containing a taxane (± anthracycline, ± platinum) and trastuzumab (± pertuzumab). Patients were randomized to adjuvant T-DM1 (n = 743) or trastuzumab (n = 743) for 14 cycles. The primary endpoint was invasive disease-free survival (IDFS). RESULTS: The incidence of peripheral neuropathy (PN) was similar regardless of neoadjuvant taxane type. Irrespective of treatment arm, baseline PN was associated with longer PN duration (median, 105-109 days longer) and lower resolution rate (∼65% versus ∼82%). Prior platinum therapy was associated with more grade 3-4 thrombocytopenia in the T-DM1 arm (13.5% versus 3.8%), but there was no grade ≥3 hemorrhage in these patients. Risk of recurrence or death was decreased with T-DM1 versus trastuzumab in patients who received anthracycline-based NACT [hazard ratio (HR) = 0.51; 95% confidence interval (CI): 0.38-0.67], non-anthracycline-based NACT (HR = 0.43; 95% CI: 0.22-0.82), presented with cT1, cN0 tumors (0 versus 6 IDFS events), or had particularly high-risk tumors (HRs ranged from 0.43 to 0.72). The central nervous system (CNS) was more often the site of first recurrence in the T-DM1 arm (5.9% versus 4.3%), but T-DM1 was not associated with a difference in overall risk of CNS recurrence. CONCLUSIONS: T-DM1 provides clinical benefit across patient subgroups, including small tumors and particularly high-risk tumors and does not increase the overall risk of CNS recurrence. NACT type had a minimal impact on safety.

Use of cyclin-dependent kinase (CDK) 4/6 inhibitors for hormone receptor-positive, human epidermal growth factor receptor 2-negative, metastatic breast cancer: a roundtable discussion by The Breast Cancer Therapy Expert Group (BCTEG).

PURPOSE: To provide an overview of clinical data supporting the use of cyclin-dependent kinases 4 and 6 (CDK 4/6) inhibitors in the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), metastatic breast cancer (mBC), from the perspective of the practicing oncologist community. METHODS: A recent roundtable discussion was convened by The Breast Cancer Therapy Expert Group (BCTEG) to review existing data on this topic and its impact on their current practice. RESULTS: Level 1 evidence now supports use of a CDK 4/6 inhibitor in combination with endocrine therapy for patients with HR+, HER2-, mBC. Currently, there are no biomarkers that reliably define patients who will, or will not, benefit from the addition of a CDK 4/6 inhibitor to their endocrine therapy. Additional research is needed to identify the optimal sequencing of CDK 4/6 inhibitors in relation to other therapies as well as the optimal duration of therapy; at present, evidence suggests that use in the upfront setting is better than waiting for a later line of therapy, or adding after endocrine therapy has started. CONCLUSIONS: Thus far, three CDK 4/6 inhibitors-palbociclib, ribociclib, and more recently, abemaciclib-have been approved for use in the setting of HR+, HER2-, mBC.  The degrees to which these agents differ in terms of CDK4/6 affinity, side-effect profiles, dosing, degree of central nervous system (CNS) penetration, optimal use in combination with antiestrogen therapy, and across other subsets of breast cancer, remain an active area of investigation.

Endocrine therapy and related issues in hormone receptor-positive early breast cancer: a roundtable discussion by the breast cancer therapy expert group (BCTEG).

PURPOSE: Management of breast cancer is a rapidly evolving field, and, although evidence-based guidelines are available for clinicians to provide direction on critical issues in patient care, clinicians often left to address these issues in the context of community practice situations with their patients. These include the patient's comorbid conditions, actual versus perceived benefit of treatments, patient's compliance as well as financial/reimbursement issues, and long-term tolerability of therapy. METHODS: A meeting of global oncology experts was convened in January 2017 with the belief that there is a gap in clinical practice guidance on several fundamental issues in breast cancer care, particularly in the community setting, where oncologists may encounter multiple tumor types. The goal was to discuss some of the most important questions in this area and provide some guidance for practicing oncologists. RESULTS: Topics addressed included risk of contralateral breast cancer recurrence in patients with estrogen receptor-positive early breast cancer who have undergone 5 years of adjuvant endocrine therapy, adverse events associated with endocrine therapy and their management, emergent data on adjuvant bisphosphonate therapy and its apparent benefit in reducing breast cancer recurrence, recent findings of extended adjuvant endocrine therapy trials, and the use of currently available genomic biomarker tests as a means of further informing treatment decisions. CONCLUSIONS: A summary of the discussion on these topics and several 'expert opinion statements' are provided herein in an effort to convey the collective insights of the panel as it relates to current standard practice.

Weekly paclitaxel and concurrent pazopanib following doxorubicin and cyclophosphamide as neoadjuvant therapy for HER-negative locally advanced breast cancer: NSABP Foundation FB-6, a phase II study.

This multicenter single-arm phase II study evaluated the addition of pazopanib to concurrent weekly paclitaxel following doxorubicin and cyclophosphamide as neoadjuvant therapy in human epidermal growth factor receptor (HER2)-negative locally advanced breast cancer (LABC). Patients with HER2-negative stage III breast cancer were treated with doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) for four cycles every 3 weeks followed by weekly paclitaxel 80 mg/m(2) on days 1, 8, and 15 every 28 days for four cycles concurrently with pazopanib 800 mg orally daily prior to surgery. Post-operatively, pazopanib was given daily for 6 months. The primary endpoint was pathologic complete response (pCR) in the breast and lymph nodes. Between July 2009 and March 2011, 101 patients with stage IIIA-C HER2-negative breast cancer were enrolled. The pCR rate in evaluable patients who initiated paclitaxel and pazopanib was 17 % (16/93). The pCR rate was 9 % (6/67) in hormone receptor-positive tumors and 38 % (10/26) in triple-negative tumors. Pre-operative pazopanib was completed in only 39 % of patients. The most frequent grade 3 and 4 adverse events during paclitaxel and pazopanib were neutropenia (27 %), diarrhea (5 %), ALT and AST elevations (each 5 %), and hypertension (5 %). Although the pCR rate of paclitaxel and pazopanib following AC chemotherapy given as neoadjuvant therapy in women with LABC met the pre-specified criteria for activity, there was substantial toxicity, which led to a high discontinuation rate of pazopanib. The combination does not appear to warrant further evaluation in the neoadjuvant setting for breast cancer.

Meta-analysis of agreement between MRI and pathologic breast tumour size after neoadjuvant chemotherapy.

BACKGROUND: Magnetic resonance imaging (MRI) has been proposed to guide breast cancer surgery by measuring residual tumour after neoadjuvant chemotherapy. This study-level meta-analysis examines MRI's agreement with pathology, compares MRI with alternative tests and investigates consistency between different measures of agreement. METHODS: A systematic literature search was undertaken. Mean differences (MDs) in tumour size between MRI or comparator tests and pathology were pooled by assuming a fixed effect. Limits of agreement (LOA) were estimated from a pooled variance by assuming equal variance of the differences across studies. RESULTS: Data were extracted from 19 studies (958 patients). The pooled MD between MRI and pathology from six studies was 0.1 cm (95% LOA: -4.2 to 4.4 cm). Similar overestimation for MRI (MD: 0.1 cm) and ultrasound (US) (MD: 0.1 cm) was observed, with comparable LOA (two studies). Overestimation was lower for MRI (MD: 0.1 cm) than mammography (MD: 0.4 cm; two studies). Overestimation by MRI (MD: 0.1 cm) was smaller than underestimation by clinical examination (MD: -0.3 cm). The LOA for mammography and clinical examination were wider than that for MRI. Percentage agreement between MRI and pathology was greater than that of comparator tests (six studies). The range of Pearson's/Spearman's correlations was wide (0.21-0.92; 16 studies). Inconsistencies between MDs, percentage agreement and correlations were common. CONCLUSION: Magnetic resonance imaging appears to slightly overestimate pathologic size, but measurement errors may be large enough to be clinically significant. Comparable performance by US was observed, but agreement with pathology was poorer for mammography and clinical examination. Percentage agreement can provide supplementary information to MDs and LOA, but Pearson's/Spearman's correlation does not provide evidence of agreement and should be avoided. Further comparisons of MRI and other tests using the recommended methods are warranted.

Early prediction of pathologic response to neoadjuvant therapy in breast cancer: systematic review of the accuracy of MRI.

Magnetic resonance imaging (MRI) has been proposed to have a role in predicting final pathologic response when undertaken early during neoadjuvant chemotherapy (NAC) in breast cancer. This paper examines the evidence for MRI's accuracy in early response prediction. A systematic literature search (to February 2011) was performed to identify studies reporting the accuracy of MRI during NAC in predicting pathologic response, including searches of MEDLINE, PREMEDLINE, EMBASE, and Cochrane databases. 13 studies were eligible (total 605 subjects, range 16-188). Dynamic contrast-enhanced (DCE) MRI was typically performed after 1-2 cycles of anthracycline-based or anthracycline/taxane-based NAC, and compared to a pre-NAC baseline scan. MRI parameters measured included changes in uni- or bidimensional tumour size, three-dimensional volume, quantitative dynamic contrast measurements (volume transfer constant [Ktrans], exchange rate constant [k(ep)], early contrast uptake [ECU]), and descriptive patterns of tumour reduction. Thresholds for identifying response varied across studies. Definitions of response included pathologic complete response (pCR), near-pCR, and residual tumour with evidence of NAC effect (range of response 0-58%). Heterogeneity across MRI parameters and the outcome definition precluded statistical meta-analysis. Based on descriptive presentation of the data, sensitivity/specificity pairs for prediction of pathologic response were highest in studies measuring reductions in Ktrans (near-pCR), ECU (pCR, but not near-pCR) and tumour volume (pCR or near-pCR), at high thresholds (typically >50%); lower sensitivity/specificity pairs were evident in studies measuring reductions in uni- or bidimensional tumour size. However, limitations in study methodology and data reporting preclude definitive conclusions. Methods proposed to address these limitations include: statistical comparison between MRI parameters, and MRI vs other tests (particularly ultrasound and clinical examination); standardising MRI thresholds and pCR definitions; and reporting changes in NAC based on test results. Further studies adopting these methods are warranted.

Centralized medical monitoring in phase III clinical trials: the National Surgical Adjuvant Breast and Bowel Project (NSABP) experience.

BACKGROUND: There is a need for data quality assurance procedures in phase III cancer trials. At the National Surgical Adjuvant Breast and Bowel Project (NSABP) 'real-time' systems have been developed for quality assurance and study monitoring: (1) manual review and triage of data forms by data managers at the time of submission; (2) computerized edit checking of all submitted data forms; (3) systematic review of eligibility, treatment compliance and toxicity in the first 100 patients of a new protocol; (4) prospective centralized medical review of all reported serious adverse events, treatment failures, second primary cancers and deaths; (5) quarterly review and approval of study summary data files by project statistician; and (6) on-site auditing. PURPOSE: To assess the utility of an additional final comprehensive review of all patient records to confirm eligibility, disease status and vital status prior to manuscript submission. METHODS: Four phase III NSABP studies, which had been monitored using the triage-based quality assurance program described above, were selected for analysis (n = 7972). Charts for 5965 patients were identified that had not been previously medically reviewed for protocol events of recurrence, second primary cancer or death. Submitted source documents and data forms of these 5965 NSABP patient records underwent medical review to verify patient eligibility, disease status and vital status. RESULTS: This final comprehensive review found no additional treatment failures or deaths, identified seven additional cases of ineligibility, was time-intensive requiring enormous use of expensive resources, and was therefore judged not to add significantly to the integrity of the database. LIMITATIONS: Our findings are influenced by the procedures the NSABP employs for quality assurance and study monitoring for Phase III clinical trials and may have limited generalizability to other settings. CONCLUSION: In the presence of multiple quality assurance and data monitoring systems, the rare discrepancies found between the data forms and source documentation does not support the routine use of a final comprehensive chart review for phase III trials at the NSABP Biostatistical Center.

Combined anthracycline-taxane regimens in the adjuvant setting.

Within the past decade there has been enormous interest in integrating the taxanes into the adjuvant breast cancer setting. Adjuvant trial designs in the early 1990s were absent of taxanes. By the mid 1990s, the taxanes were included in adjuvant trials, but were mainly limited to trials conducted in node-positive patients. Currently, taxanes are a chemotherapeutic modality in the majority of ongoing adjuvant trials in both node-negative and node-positive patients. These trials are being conducted in thousands of patients worldwide by several of the cooperative research organizations. Most of the adjuvant trials have focused on defining the clinical efficacy and toxicity of the concurrent or sequential use of taxanes with anthracyclines. The collective experience with taxanes over the next 3 to 5 years will make them one of the most intensely studied treatments in the history of patients with breast cancer. The outcome of these trials is greatly anticipated because they have the potential of changing the current standards of care in the adjuvant treatment of patients with breast cancer.

Preoperative (neoadjuvant) chemotherapy in patients with breast cancer.

The concept of using preoperative chemotherapy in patients with operable breast cancer originated from experimental and clinical observations, as well as from theoretical hypotheses on tumor cell growth and dissemination. Results from nonrandomized studies with different chemotherapeutic agents or combination regimens given preoperatively demonstrated substantial clinical response rates but low pathologic tumor response rates. In addition, several such studies were able to show that-by reducing primary breast tumor size-preoperative chemotherapy can lead to an increase in the rate of breast-preserving procedures. Although nonrandomized studies provided useful clinical information about the effect of preoperative chemotherapy on primary breast tumors and on axillary nodes involved with tumor, they could not address the relative efficacy of preoperative versus postoperative (adjuvant) chemotherapy on disease-free survival (DFS) and overall survival (OS). As a result, several randomized trials were implemented to address the above questions. Some of the earlier trials, however, were not designed as straightforward comparisons of preoperative versus postoperative chemotherapy and, thus, did not provide meaningful answers to the fundamental question of whether DFS and OS can be prolonged by the administration of chemotherapy before surgery rather than after. The National Surgical Adjuvant Breast and Bowel Project (NSABP) B-18 trial was the largest randomized trial that aimed to compare preoperative to postoperative chemotherapy in operable breast cancer. Results from this trial on the effect of preoperative chemotherapy on local-regional disease and outcome are presented. The potential advantages and disadvantages of each approach, as well as surgical considerations and current and future directions in the use of preoperative chemotherapy, are also discussed.

Prevention of invasive breast cancer in women with ductal carcinoma in situ: an update of the National Surgical Adjuvant Breast and Bowel Project experience.

The National Surgical Adjuvant Breast and Bowel Project (NSABP) conducted two sequential randomized clinical trials to aid in resolving uncertainty about the treatment of women with small, localized, mammographically detected ductal carcinoma in situ (DCIS). After removal of the tumor and normal breast tissue so that specimen margins were histologically tumor-free (lumpectomy), 818 patients in the B-17 trial were randomly assigned to receive either radiation therapy to the ipsilateral breast or no radiation therapy. B-24, the second study, which involved 1,804 women, tested the hypothesis that, in DCIS patients with or without positive tumor specimen margins, lumpectomy, radiation, and tamoxifen (TAM) would be more effective than lumpectomy, radiation, and placebo in preventing invasive and noninvasive ipsilateral breast tumor recurrences (IBTRs), contralateral breast tumors (CBTs), and tumors at metastatic sites. The findings in this report continue to demonstrate through 12 years of follow-up that radiation after lumpectomy reduces the incidence rate of all IBTRs by 58%. They also demonstrate that the administration of TAM after lumpectomy and radiation therapy results in a significant decrease in the rate of all breast cancer events, particularly in invasive cancer. The findings from the B-17 and B-24 studies are related to those from the NSABP prevention (P-1) trial, which demonstrated a 50% reduction in the risk of invasive cancer in women with a history of atypical ductal hyperplasia (ADH) or lobular carcinoma in situ (LCIS) and a reduction in the incidence of both DCIS and LCIS in women without a history of those tumors. The B-17 findings demonstrated that patients treated with lumpectomy alone were at greater risk for invasive cancer than were women in P-1 who had a history of ADH or LCIS and who received no radiation therapy or TAM. Although women who received radiation benefited from that therapy, they remained at higher risk for invasive cancer than women in P-1 who had a history of LCIS and who received placebo or TAM. Thus, if it is accepted from the P-1 findings that women at increased risk for invasive cancer are candidates for an intervention such as TAM, then it would seem that women with a history of DCIS should also be considered for such therapy in addition to radiation therapy. That statement does not imply that, as a result of the findings presented here, all DCIS patients should receive radiation and TAM. It does suggest, however, that, in the treatment of DCIS, the appropriate use of current and better therapeutic agents that become available could diminish the significance of breast cancer as a public health problem.

Adjuvant exemestane therapy after 5 years of tamoxifen: rationale for the NSABP B-33 trial.

Tamoxifen (Nolvadex) has long been established as "standard" adjuvant therapy for receptor-positive, early-stage breast cancer. Results from clinical trials suggest that after approximately 5 years, tamoxifen may lose its effectiveness and may even become harmful if not stopped. At the time of tamoxifen discontinuation, "seemingly" disease-free patients may still have residual micrometastatic tumor cells. In a proportion of such patients, these cells may still be responsive to tamoxifen and thus could grow as a result of stopping the drug. The majority of clinical information, however, suggests that by 5 years of therapy, a greater proportion of patients will have micrometastatic tumor cells that have become resistant to tamoxifen and will be stimulated by continuation of the drug for a longer time. Because in both such cases the micrometastases are hormonally sensitive, a reasonable approach--in addition to stopping tamoxifen--is to decrease the level of estrogenic stimulation by introducing an aromatase inhibitor. The National Surgical Adjuvant Breast and Bowel Project is launching a clinical trial (NSABP B-33) to evaluate the sequential administration of 2 years of exemestane (Aromasin), a steroidal aromatase inactivator, after 5 years of tamoxifen in postmenopausal, receptor-positive patients who are disease-free at the time of tamoxifen discontinuation.

Findings from recent National Surgical Adjuvant Breast and Bowel Project adjuvant studies in stage I breast cancer.

Before 1989, credible information about the treatment of breast cancer was derived mainly from randomized clinical trials that enrolled women with either metastatic (stage IV); locally advanced (stage III); or primary, operable, axillary lymph node-positive (stage II) disease. This report provides information from six recent National Surgical Adjuvant Breast and Bowel Project (NSABP) trials involving lymph node-negative (stage I) patients. Findings from NSABP B-13 demonstrated, through 14 years of follow-up, improvements in disease-free survival (DFS) and overall survival from methotrexate and fluorouracil (MF), regardless of age, in women with estrogen receptor (ER)-negative tumors. Results from NSABP B-19, which was conducted with similar patients, demonstrated, through 8 years, a greater overall DFS and survival advantage with cyclophosphamide and MF (CMF) than that observed with MF. Findings from NSABP B-23, in which patients similar to those in B-13 and B-19 were randomly assigned to receive CMF plus placebo, CMF plus tamoxifen (TAM), doxorubicin (Adriamycin) and cyclophosphamide (AC) plus placebo, or AC plus TAM, demonstrated no difference in relapse-free survival (RFS) or overall survival among the four groups through 5 years, either for all patients or relative to age. NSABP B-14, which was carried out in women with ER-positive tumors, compared the outcomes of those who received either placebo or TAM. Through 14 years, superior DFS and overall survival advantages, as well as a reduction in contralateral breast cancer, were observed with TAM. No additional benefit resulted from TAM administration beyond 5 years. Findings from NSABP B-20, a second study conducted in patients with ER-positive tumors, showed, after 8 years, both a DFS and an overall survival advantage from TAM plus either MF or CMF over that achieved with TAM alone. A recent meta-analysis in women with negative lymph nodes and either ER-negative or ER-positive tumors of less than or equal to 1 cm in size was conducted using patients from five NSABP trials. After 8 years, the RFS in women with ER-negative tumors was greater in the group treated with surgery and chemotherapy than in those who underwent surgery alone. In women with ER-positive tumors, RFS and overall survival advantages were observed from the addition of chemotherapy to TAM when that treatment regimen was compared with TAM alone. In addition, evidence has been presented from NSABP B-21, a trial evaluating radiation therapy (XRT) and/or TAM for the prevention of ipsilateral breast tumor recurrence (IBTR) after lumpectomy in women with tumors less than or equal to 1 cm. Findings have shown that XRT is superior to TAM and that XRT + TAM is superior to XRT alone for preventing IBTR. The findings demonstrate that chemotherapy and/or hormonal therapy is effective for the management of women with negative axillary lymph nodes and either ER-negative or ER-positive tumors. Because it also has been proven effective in women with tumors less than or equal to 1 cm, such therapy might also be considered in the treatment of that patient population.

Preoperative chemotherapy in patients with operable breast cancer: nine-year results from National Surgical Adjuvant Breast and Bowel Project B-18.

National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol B-18 was initiated in 1988 to determine whether four cycles of doxorubicin/cyclophosphamide given preoperatively improve survival and disease-free survival (DFS) when compared with the same chemotherapy given postoperatively. Secondary aims included the evaluation of preoperative chemotherapy in downstaging the primary breast tumor and involved axillary lymph nodes, the comparison of lumpectomy rates and rates of ipsilateral breast tumor recurrence (IBTR) in the two treatment groups, and the assessment of the correlation between primary tumor response and outcome. Initially published findings were based on a follow-up of 5 years; this report updates results through 9 years of follow-up. There continue to be no statistically significant overall differences in survival or DFS between the two treatment groups. Survival at 9 years is 70% in the postoperative group and 69% in the preoperative group (P =.80). DFS is 53% in postoperative patients and 55% in preoperative patients (P =.50). A statistically significant correlation persists between primary tumor response and outcome, and this correlation has become statistically stronger with longer follow-up. Patients assigned to preoperative chemotherapy received notably more lumpectomies than postoperative patients, especially among patients with tumors greater than 5 cm at study entry. Although the rate of IBTR was slightly higher in the preoperative group (10.7% versus 7.6%), this difference was not statistically significant. Marginally statistically significant treatment-by-age interactions appear to be emerging for survival and DFS, suggesting that younger patients may benefit from preoperative therapy, whereas the reverse may be true for older patients.

Present state and future prospects: a review of cooperative groups' adjuvant and neoadjuvant trials in breast cancer.

In patients with operable breast cancer, adjuvant hormonal therapy and adjuvant chemotherapy result in significant and long-term reductions in the rates of disease recurrence and death. These reductions are evident in both patients with node-negative as well as in those with node-positive disease. However, several issues in the adjuvant treatment of breast cancer still remain unresolved. These issues were recently considered at the 2000 National Institutes of Health (NIH) Consensus Development Conference, which reviewed the current state of knowledge on adjuvant therapy and outlined strategies for future research. In the area of adjuvant hormonal therapy, tamoxifen is still the gold standard, and present evidence supports the use of tamoxifen for patients with estrogen receptor (ER)-positive tumors irrespective of age, menopausal status, nodal status, or tumor size. Optimal duration of tamoxifen therapy is about 5 years. Future research directions include evaluating the benefit of extending tamoxifen beyond 5 years, the contribution of ovarian ablation, and the role of hormonal manipulations involving selective ER modulators and aromatase inhibitors instead of or in addition to tamoxifen. In the area of adjuvant chemotherapy, polychemotherapy regimens have been consistently found to be superior to single agents, and anthracycline-containing regimens produce a small but statistically significant improvement in survival when compared with regimens not containing an anthracycline. High-dose adjuvant chemotherapy with stem cell support has not been proven superior to standard regimens. Neoadjuvant therapy offers the possibility of testing in vivo the sensitivity of individual tumors to particular cytotoxic regimens and, hence, of improving ultimate disease control, as well as reducing the extent of local therapy. The contribution and optimal integration of taxanes in the adjuvant setting are yet to be established but are the subject of intense research effort. Similarly, novel targeted therapies such as trastuzumab and bisphosphonates are currently being evaluated in adjuvant studies

UFT/leucovorin vs 5-FU/leucovorin in colon cancer.

Adjuvant chemotherapy has been shown to alter the natural history of resected colon cancer. Two regimens (fluorouracil [5-FU] plus leucovorin and 5-FU plus levamisole) have been found to prolong disease-free survival and overall survival in affected patients. Previous comparisons of these two regimens indicate that 5-FU plus leucovorin may offer a small disease-free survival and overall survival advantage. Evidence that UFT (uracil and tegafur) plus oral leucovorin is associated with significant antitumor activity and has an acceptable toxicity profile makes this a logical formulation for the adjuvant treatment of colon cancer. The National Surgical Adjuvant Breast and Bowel Project Protocol C-06 is a randomized comparison of the relative efficacies of 5-FU plus leucovorin vs UFT plus leucovorin. Preliminary analysis of the toxicity findings among 1,530 evaluable patients indicates that both regimens are well tolerated and have similar toxicity profiles.