Priya Rastogi

Preoperative Chemotherapy: Updates of National Surgical Adjuvant Breast and Bowel Project Protocols B-18 and B-27

PURPOSE National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol B-18 was designed to determine whether four cycles of doxorubicin and cyclophosphamide (AC) administered preoperatively improved breast cancer disease-free survival (DFS) and overall survival (OS) compared with AC administered postoperatively. Protocol B-27 was designed to determine the effect of adding docetaxel (T) to preoperative AC on tumor response rates, DFS, and OS. PATIENTS AND METHODS Analyses were limited to eligible patients. In B-18, 751 patients were assigned to receive preoperative AC, and 742 patients were assigned to receive postoperative AC. In B-27, 784 patients were assigned to receive preoperative AC followed by surgery, 783 patients were assigned to AC followed by T and surgery, and 777 patients were assigned to AC followed by surgery and then T. RESULTS Results from B-18 show no statistically significant differences in DFS and OS between the two groups. However, there were trends in favor of preoperative chemotherapy for DFS and OS in women less than 50 years old (hazard ratio [HR] = 0.85, P = .09 for DFS; HR = 0.81, P = .06 for OS). DFS conditional on being event free for 5 years also demonstrated a strong trend in favor of the preoperative group (HR = 0.81, P = .053). Protocol B-27 results demonstrated that the addition of T to AC did not significantly impact DFS or OS. Preoperative T added to AC significantly increased the proportion of patients having pathologic complete responses (pCRs) compared with preoperative AC alone (26% v 13%, respectively; P < .0001). In both studies, patients who achieved a pCR continue to have significantly superior DFS and OS outcomes compared with patients who did not. CONCLUSION B-18 and B-27 demonstrate that preoperative therapy is equivalent to adjuvant therapy. B-27 also showed that the addition of preoperative taxanes to AC improves response.

Pathological complete response and long-term clinical benefit in breast cancer: the CTNeoBC pooled analysis

BACKGROUND Pathological complete response has been proposed as a surrogate endpoint for prediction of long-term clinical benefit, such as disease-free survival, event-free survival (EFS), and overall survival (OS). We had four key objectives: to establish the association between pathological complete response and EFS and OS, to establish the definition of pathological complete response that correlates best with long-term outcome, to identify the breast cancer subtypes in which pathological complete response is best correlated with long-term outcome, and to assess whether an increase in frequency of pathological complete response between treatment groups predicts improved EFS and OS. METHODS We searched PubMed, Embase, and Medline for clinical trials of neoadjuvant treatment of breast cancer. To be eligible, studies had to meet three inclusion criteria: include at least 200 patients with primary breast cancer treated with preoperative chemotherapy followed by surgery; have available data for pathological complete response, EFS, and OS; and have a median follow-up of at least 3 years. We compared the three most commonly used definitions of pathological complete response--ypT0 ypN0, ypT0/is ypN0, and ypT0/is--for their association with EFS and OS in a responder analysis. We assessed the association between pathological complete response and EFS and OS in various subgroups. Finally, we did a trial-level analysis to assess whether pathological complete response could be used as a surrogate endpoint for EFS or OS. FINDINGS We obtained data from 12 identified international trials and 11 955 patients were included in our responder analysis. Eradication of tumour from both breast and lymph nodes (ypT0 ypN0 or ypT0/is ypN0) was better associated with improved EFS (ypT0 ypN0: hazard ratio [HR] 0·44, 95% CI 0·39-0·51; ypT0/is ypN0: 0·48, 0·43-0·54) and OS (0·36, 0·30-0·44; 0·36, 0·31-0·42) than was tumour eradication from the breast alone (ypT0/is; EFS: HR 0·60, 95% CI 0·55-0·66; OS 0·51, 0·45-0·58). We used the ypT0/is ypN0 definition for all subsequent analyses. The association between pathological complete response and long-term outcomes was strongest in patients with triple-negative breast cancer (EFS: HR 0·24, 95% CI 0·18-0·33; OS: 0·16, 0·11-0·25) and in those with HER2-positive, hormone-receptor-negative tumours who received trastuzumab (EFS: 0·15, 0·09-0·27; OS: 0·08, 0·03, 0·22). In the trial-level analysis, we recorded little association between increases in frequency of pathological complete response and EFS (R(2)=0·03, 95% CI 0·00-0·25) and OS (R(2)=0·24, 0·00-0·70). INTERPRETATION Patients who attain pathological complete response defined as ypT0 ypN0 or ypT0/is ypN0 have improved survival. The prognostic value is greatest in aggressive tumour subtypes. Our pooled analysis could not validate pathological complete response as a surrogate endpoint for improved EFS and OS. FUNDING US Food and Drug Administration.

Assessment of Cardiac Dysfunction in a Randomized Trial Comparing Doxorubicin and Cyclophosphamide Followed by Paclitaxel, With or Without Trastuzumab As Adjuvant Therapy in Node-Positive, Human Epidermal Growth Factor Receptor 2–Overexpressing Breast Cancer: NSABP B-31

PURPOSE Trastuzumab is effective in treating human epidermal growth factor receptor 2 (HER2) -positive breast cancer, but it increases frequency of cardiac dysfunction (CD) when used with or after anthracyclines. PATIENTS AND METHODS National Surgical Adjuvant Breast and Bowel Project trial B-31 compared doxorubicin and cyclophosphamide (AC) followed by paclitaxel with AC followed by paclitaxel plus 52 weeks of trastuzumab beginning concurrently with paclitaxel in patients with node-positive, HER2-positive breast cancer. Initiation of trastuzumab required normal post-AC left ventricular ejection fraction (LVEF) on multiple-gated acquisition scan. If symptoms suggestive of congestive heart failure (CHF) developed, source documents were blindly reviewed by an independent panel of cardiologists to determine whether criteria were met for a cardiac event (CE), which was defined as New York Heart Association class III or IV CHF or possible/probable cardiac death. Frequencies of CEs were compared between arms. RESULTS Among patients with normal post-AC LVEF who began post-AC treatment, five of 814 control patients subsequently had confirmed CEs (four CHFs and one cardiac death) compared with 31 of 850 trastuzumab-treated patients (31 CHFs and no cardiac deaths). The difference in cumulative incidence at 3 years was 3.3% (4.1% for trastuzumab-treated patients minus 0.8% for control patients; 95% CI, 1.7% to 4.9%). Twenty-seven of the 31 patients in the trastuzumab arm have been followed for > or = 6 months after diagnosis of a CE; 26 were asymptomatic at last assessment, and 18 remained on cardiac medication. CHFs were more frequent in older patients and patients with marginal post-AC LVEF. Fourteen percent of patients discontinued trastuzumab because of asymptomatic decreases in LVEF; 4% discontinued trastuzumab because of symptomatic cardiotoxicity. CONCLUSION Administering trastuzumab with paclitaxel after AC increases incidence of CHF and lesser CD. Potential cardiotoxicity should be carefully considered when discussing benefits and risks of this therapy.

Bevacizumab Added to Neoadjuvant Chemotherapy for Breast Cancer

BACKGROUND Bevacizumab and the antimetabolites capecitabine and gemcitabine have been shown to improve outcomes when added to taxanes in patients with metastatic breast cancer. The primary aims of this trial were to determine whether the addition of capecitabine or gemcitabine to neoadjuvant chemotherapy with docetaxel, followed by doxorubicin plus cyclophosphamide, would increase the rates of pathological complete response in the breast in women with operable, human epidermal growth factor receptor 2 (HER2)-negative breast cancer and whether adding bevacizumab to these chemotherapy regimens would increase the rates of pathological complete response. METHODS We randomly assigned 1206 patients to receive neoadjuvant therapy consisting of docetaxel (100 mg per square meter of body-surface area on day 1), docetaxel (75 mg per square meter on day 1) plus capecitabine (825 mg per square meter twice a day on days 1 to 14), or docetaxel (75 mg per square meter on day 1) plus gemcitabine (1000 mg per square meter on days 1 and 8) for four cycles, with all regimens followed by treatment with doxorubicin-cyclophosphamide for four cycles. Patients were also randomly assigned to receive or not to receive bevacizumab (15 mg per kilogram of body weight) for the first six cycles of chemotherapy. RESULTS The addition of capecitabine or gemcitabine to docetaxel therapy, as compared with docetaxel therapy alone, did not significantly increase the rate of pathological complete response (29.7% and 31.8%, respectively, vs. 32.7%; P=0.69). Both capecitabine and gemcitabine were associated with increased toxic effects--specifically, the hand-foot syndrome, mucositis, and neutropenia. The addition of bevacizumab significantly increased the rate of pathological complete response (28.2% without bevacizumab vs. 34.5% with bevacizumab, P=0.02). The effect of bevacizumab on the rate of pathological complete response was not the same in the hormone-receptor-positive and hormone-receptor-negative subgroups. The addition of bevacizumab increased the rates of hypertension, left ventricular systolic dysfunction, the hand-foot syndrome, and mucositis. CONCLUSIONS The addition of bevacizumab to neoadjuvant chemotherapy significantly increased the rate of pathological complete response, which was the primary end point of this study. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00408408.).

Trastuzumab Plus Adjuvant Chemotherapy for Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer: Planned Joint Analysis of Overall Survival From NSABP B-31 and NCCTG N9831

PURPOSE Positive interim analysis findings from four large adjuvant trials evaluating trastuzumab in patients with early-stage human epidermal growth factor receptor 2 (HER2) -positive breast cancer were first reported in 2005. One of these reports, the joint analysis of North Central Cancer Treatment Group NCCTG N9831 (Combination Chemotherapy With or Without Trastuzumab in Treating Women With HER2-Overexpressing Breast Cancer) and the National Surgical Adjuvant Breast and Bowel Project NSABP B-31 (Doxorubicin and Cyclophosphamide Plus Paclitaxel With or Without Trastuzumab in Treating Women With Node-Positive Breast Cancer That Overexpresses HER2), was updated in 2011. We now report the planned definitive overall survival (OS) results from this joint analysis along with updates on the disease-free survival (DFS) end point. METHODS In all, 4,046 patients with HER2-positive operable breast cancer were enrolled to receive doxorubicin and cyclophosphamide followed by paclitaxel with or without trastuzumab in both trials. The required number of events for the definitive statistical analysis for OS (710 events) was reached in September 2012. Updated analyses of overall DFS and related subgroups were also performed. RESULTS Median time on study was 8.4 years. Adding trastuzumab to chemotherapy led to a 37% relative improvement in OS (hazard ratio [HR], 0.63; 95% CI, 0.54 to 0.73; P < .001) and an increase in 10-year OS rate from 75.2% to 84%. These results were accompanied by an improvement in DFS of 40% (HR, 0.60; 95% CI, 0.53 to 0.68; P < .001) and increase in 10-year DFS rate from 62.2% to 73.7%. All patient subgroups benefited from addition of this targeted anti-HER2 agent. CONCLUSION The addition of trastuzumab to paclitaxel after doxorubicin and cyclophosphamide in early-stage HER2-positive breast cancer results in a substantial and durable improvement in survival as a result of a sustained marked reduction in cancer recurrence.

Seven-Year Follow-Up Assessment of Cardiac Function in NSABP B-31, a Randomized Trial Comparing Doxorubicin and Cyclophosphamide Followed by Paclitaxel (ACP) With ACP Plus Trastuzumab As Adjuvant Therapy for Patients With Node-Positive, Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer

PURPOSE Cardiac dysfunction (CD) is a recognized risk associated with the addition of trastuzumab to adjuvant chemotherapy for human epidermal growth factor receptor 2-positive breast cancer, especially when the treatment regimen includes anthracyclines. Given the demonstrated efficacy of trastuzumab, ongoing assessment of cardiac safety and identification of risk factors for CD are important for optimal patient care. PATIENTS AND METHODS In National Surgical Adjuvant Breast and Bowel Project B-31, a phase III adjuvant trial, 1,830 patients who met eligibility criteria for initiation of trastuzumab were evaluated for CD. Recovery from CD was also assessed. A statistical model was developed to estimate the risk of severe congestive heart failure (CHF). Baseline patient characteristics associated with anthracycline-related decline in cardiac function were also identified. RESULTS At 7-year follow-up, 37 (4.0%) of 944 patients who received trastuzumab experienced a cardiac event (CE) versus 10 (1.3%) of 743 patients in the control arm. One cardiac-related death has occurred in each arm of the protocol. A Cardiac Risk Score, calculated using patient age and baseline left ventricular ejection fraction (LVEF) by multiple-gated acquisition scan, statistically correlates with the risk of a CE. After stopping trastuzumab, the majority of patients who experienced CD recovered LVEF in the normal range, although some decline from baseline often persists. Only two CEs occurred more than 2 years after initiation of trastuzumab. CONCLUSION The late development of CHF after the addition of trastuzumab to paclitaxel after doxorubicin/ cyclophosphamide chemotherapy is uncommon. The risk versus benefit of trastuzumab as given in this regimen remains strongly in favor of trastuzumab.

Longer Therapy, Iatrogenic Amenorrhea, and Survival in Early Breast Cancer

BACKGROUND Chemotherapy regimens that combine anthracyclines and taxanes result in improved disease-free and overall survival among women with operable lymph-node-positive breast cancer. The effectiveness of concurrent versus sequential regimens is not known. METHODS We randomly assigned 5351 patients with operable, node-positive, early-stage breast cancer to receive four cycles of doxorubicin and cyclophosphamide followed by four cycles of docetaxel (sequential ACT); four cycles of doxorubicin and docetaxel (doxorubicin-docetaxel); or four cycles of doxorubicin, cyclophosphamide, and docetaxel (concurrent ACT). The primary aims were to examine whether concurrent ACT was more effective than sequential ACT and whether the doxorubicin-docetaxel regimen would be as effective as the concurrent-ACT regimen. The secondary aims were to assess toxic effects and to correlate amenorrhea with outcomes in premenopausal women. RESULTS At a median follow-up of 73 months, overall survival was improved in the sequential-ACT group (8-year overall survival, 83%) as compared with the doxorubicin-docetaxel group (overall survival, 79%; hazard ratio for death, 0.83; P=0.03) and the concurrent-ACT group (overall survival, 79%; hazard ratio, 0.86; P=0.09). Disease-free survival was improved in the sequential-ACT group (8-year disease-free survival, 74%) as compared with the doxorubicin-docetaxel group (disease-free survival, 69%; hazard ratio for recurrence, a second malignant condition, or death, 0.80; P=0.001) and the concurrent-ACT group (disease-free survival, 69%; hazard ratio, 0.83; P=0.01). The doxorubicin-docetaxel regimen showed noninferiority to the concurrent-ACT regimen for overall survival (hazard ratio, 0.96; 95% confidence interval, 0.82 to 1.14). Overall survival was improved in patients with amenorrhea for 6 months or more across all treatment groups, independently of estrogen-receptor status. CONCLUSIONS Sequential ACT improved disease-free survival as compared with doxorubicin-docetaxel or concurrent ACT, and it improved overall survival as compared with doxorubicin-docetaxel. Amenorrhea was associated with improved survival regardless of the treatment and estrogen-receptor status. (ClinicalTrials.gov number, NCT00003782.)

Lapatinib as a component of neoadjuvant therapy for HER2-positive operable breast cancer (NSABP protocol B-41): an open-label, randomised phase 3 trial

BACKGROUND We studied the effect on tumour response to neoadjuvant therapy of the substitution of lapatinib for trastuzumab in combination with weekly paclitaxel after doxorubicin plus cyclophosphamide treatment, and of the addition of lapatinib and trastuzumab combined after doxorubicin plus cyclophosphamide treatment in patients with HER2-positive operable breast cancer to determine whether there would be a benefit of dual HER2 blockade in these patients. METHODS For this open-label, randomised phase 3 trial we recruited women aged 18 years or older with an ECOG performance status of 0 or 1 with operable HER2-positive breast cancer. Each received four cycles of standard doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) intravenously on day 1 every 3 weeks followed by four cycles of weekly paclitaxel (80 mg/m(2)) intravenously on days 1, 8, and 15, every 4 weeks. Concurrently with weekly paclitaxel, patients received either trastuzumab (4 mg/kg load, then 2 mg/kg intravenously) weekly until surgery, lapatinib (1250 mg orally) daily until surgery, or weekly trastuzumab plus lapatinib (750 mg orally) daily until surgery. After surgery, all patients received trastuzumab to complete 52 weeks of HER2-targeted therapy. Randomisation (ratio 1:1:1) was done centrally with stratification by clinical tumour size, clinical nodal status, hormone-receptor status, and age. The primary endpoint was the pathological complete response in the breast, and analysis was performed on an intention-to-treat population. FINDINGS Patient accrual started on July 16, 2007, and was completed on June 30, 2011; 529 women were enrolled in the trial. 519 patients had their pathological response determined. Breast pathological complete response was noted in 93 (52·5%, 95% CI 44·9-59·5) of 177 patients in the trastuzumab group, 91 (53·2%, 45·4-60·3) of 171 patients in the lapatinib group (p=0·9852); and 106 (62·0%, 54·3-68·8) of 171 patients in the combination group (p=0·095). The most common grade 3 and 4 toxic effects were neutropenia (29 [16%] patients in the trastuzumab group [grade 4 in five patients (3%), 28 [16%] in the lapatinib group [grade 4 in eight patients (5%)], and 29 [17%] in the combination group [grade 4 in nine patients (5%)]) and grade 3 diarrhoea (four [2%] patients in the trastuzumab group, 35 [20%] in the lapatinib group, and 46 [27%] in the combination group; p<0·0001). Symptomatic congestive heart failure defined as New York Heart Association Class III or IV events occurred in seven (4%) patients in the trastuzumab group, seven (4%) in the lapatinib group, and one (<1%) in the combination group; p=0·185). INTERPRETATION Substitution of lapatinib for trastuzumab in combination with chemotherapy resulted in similar high percentages of pathological complete response. Combined HER2-targeted therapy produced a numerically but insignificantly higher pathological complete response percentage than single-agent HER2-directed therapy; these findings are consistent with results from other studies. Trials are being undertaken to further assess these findings in the adjuvant setting.

Evaluation of metformin in early breast cancer: a modification of the traditional paradigm for clinical testing of anti-cancer agents

Metformin, an inexpensive oral agent commonly used to treat type 2 diabetes, has been garnering increasing attention as a potential anti-cancer agent. Preclinical, epidemiologic, and clinical evidences suggest that metformin may reduce overall cancer risk and mortality, with specific effects in breast cancer. The extensive clinical experience with metformin, coupled with its known (and modest) toxicity, has allowed the traditional process of drug evaluation to be shortened. We review the rationale for a modified approach to evaluation and outline the key steps that will optimize development of this agent in breast cancer, including discussion of a Phase III adjuvant trial (NCIC MA.32) that has recently been initiated.

Memory impairments with adjuvant anastrozole versus tamoxifen in women with early-stage breast cancer

Objective: Hormones have been implicated as modulators of cognitive functioning. For instance, results of our previous work in women with breast cancer showed that cognitive impairment was more severe and involved more memory domains in those who received adjuvant tamoxifen therapy compared with women who received chemotherapy alone or no adjuvant therapy. Recently aromatase inhibitors such as anastrozole have been used in lieu of tamoxifen for the adjuvant treatment of postmenopausal women with hormone receptor-positive, early-stage breast cancer. Plasma estrogen levels are significantly lower in women who receive anastrozole compared with those who receive tamoxifen. We hypothesized, therefore, that anastrozole would have a more profound effect on cognitive function than tamoxifen, a mixed estrogen agonist/antagonist. Design: To test this hypothesis we compared cognitive function in women with early-stage breast cancer who received tamoxifen with those who received anastrozole therapy in a cross-sectional study. We evaluated cognitive function, depression, anxiety, and fatigue in 31 postmenopausal women with early-stage breast cancer who were between the ages of 21 and 65 years and treated with tamoxifen or anastrozole for a minimum of 3 months. Results: The results showed that women who received anastrozole had poorer verbal and visual learning and memory than women who received tamoxifen. Conclusions: Additional, prospective studies are needed to validate and confirm the changes in cognitive function associated with hormone therapy for breast cancer.