Nicholas J. Robert

Multinational Study of the Efficacy and Safety of Humanized Anti-HER2 Monoclonal Antibody in Women Who Have HER2-Overexpressing Metastatic Breast Cancer That Has Progressed After Chemotherapy for Metastatic Disease

PURPOSE Overexpression of the HER2 protein occurs in 25% to 30% of human breast cancers and leads to a particularly aggressive form of the disease. Efficacy and safety of recombinant humanized anti-HER2 monoclonal antibody as a single agent was evaluated in women with HER2-overexpressing metastatic breast cancer that had progressed after chemotherapy for metastatic disease. PATIENTS AND METHODS Two hundred twenty-two women, with HER2-overexpressing metastatic breast cancer that had progressed after one or two chemotherapy regimens, were enrolled. Patients received a loading dose of 4 mg/kg intravenously, followed by a 2-mg/kg maintenance dose at weekly intervals. RESULTS Study patients had advanced metastatic disease and had received extensive prior therapy. A blinded, independent response evaluation committee identified eight complete and 26 partial responses, for an objective response rate of 15% in the intent-to-treat population (95% confidence interval, 11% to 21%). The median duration of response was 9.1 months; the median duration of survival was 13 months. The most common adverse events, which occurred in approximately 40% of patients, were infusion-associated fever and/or chills that usually occurred only during the first infusion, and were of mild to moderate severity. These symptoms were treated successfully with acetaminophen and/or diphenhydramine. The most clinically significant adverse event was cardiac dysfunction, which occurred in 4.7% of patients. Only 1% of patients discontinued the study because of treatment-related adverse events. CONCLUSION Recombinant humanized anti-HER2 monoclonal antibody, administered as a single agent, produces durable objective responses and is well tolerated by women with HER2-overexpressing metastatic breast cancer that has progressed after chemotherapy for metastatic disease. Side effects that are commonly observed with chemotherapy, such as alopecia, mucositis, and neutropenia, are rarely seen.

Adjuvant Trastuzumab in HER2-Positive Breast Cancer

BACKGROUND Trastuzumab improves survival in the adjuvant treatment of HER-positive breast cancer, although combined therapy with anthracycline-based regimens has been associated with cardiac toxicity. We wanted to evaluate the efficacy and safety of a new nonanthracycline regimen with trastuzumab. METHODS We randomly assigned 3222 women with HER2-positive early-stage breast cancer to receive doxorubicin and cyclophosphamide followed by docetaxel every 3 weeks (AC-T), the same regimen plus 52 weeks of trastuzumab (AC-T plus trastuzumab), or docetaxel and carboplatin plus 52 weeks of trastuzumab (TCH). The primary study end point was disease-free survival. Secondary end points were overall survival and safety. RESULTS At a median follow-up of 65 months, 656 events triggered this protocol-specified analysis. The estimated disease-free survival rates at 5 years were 75% among patients receiving AC-T, 84% among those receiving AC-T plus trastuzumab, and 81% among those receiving TCH. Estimated rates of overall survival were 87%, 92%, and 91%, respectively. No significant differences in efficacy (disease-free or overall survival) were found between the two trastuzumab regimens, whereas both were superior to AC-T. The rates of congestive heart failure and cardiac dysfunction were significantly higher in the group receiving AC-T plus trastuzumab than in the TCH group (P<0.001). Eight cases of acute leukemia were reported: seven in the groups receiving the anthracycline-based regimens and one in the TCH group subsequent to receiving an anthracycline outside the study. CONCLUSIONS The addition of 1 year of adjuvant trastuzumab significantly improved disease-free and overall survival among women with HER2-positive breast cancer. The risk-benefit ratio favored the nonanthracycline TCH regimen over AC-T plus trastuzumab, given its similar efficacy, fewer acute toxic effects, and lower risks of cardiotoxicity and leukemia. (Funded by Sanofi-Aventis and Genentech; BCIRG-006 ClinicalTrials.gov number, NCT00021255.).

RIBBON-1: Randomized, Double-Blind, Placebo-Controlled, Phase III Trial of Chemotherapy With or Without Bevacizumab for First-Line Treatment of Human Epidermal Growth Factor Receptor 2–Negative, Locally Recurrent or Metastatic Breast Cancer

PURPOSE This phase III study compared the efficacy and safety of bevacizumab (BV) when combined with several standard chemotherapy regimens versus those regimens alone for first-line treatment of patients with human epidermal growth factor receptor 2-negative metastatic breast cancer. PATIENTS AND METHODS Patients were randomly assigned in 2:1 ratio to chemotherapy plus BV or chemotherapy plus placebo. Before random assignment, investigators chose capecitabine (Cape; 2,000 mg/m(2) for 14 days), taxane (Tax) -based (nab-paclitaxel 260 mg/m(2), docetaxel 75 or 100 mg/m(2)), or anthracycline (Anthra) -based (doxorubicin or epirubicin combinations [doxorubicin/cyclophosphamide, epirubicin/cyclophosphamide, fluorouracil/epirubicin/cyclophosphamide, or fluorouracil/doxorubicin/cyclophosphamide]) chemotherapy administered every 3 weeks. BV or placebo was administered at 15 mg/kg every 3 weeks. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), 1-year survival rate, objective response rate, duration of objective response, and safety. Two independently powered cohorts defined by the choice of chemotherapy (Cape patients or pooled Tax/Anthra patients) were analyzed in parallel. RESULTS RIBBON-1 (Regimens in Bevacizumab for Breast Oncology) enrolled 1,237 patients (Cape cohort, n = 615; Tax/Anthra cohort, n = 622). Median PFS was longer for each BV combination (Cape cohort: increased from 5.7 months to 8.6 months; hazard ratio [HR], 0.69; 95% CI, 0.56 to 0.84; log-rank P < .001; and Tax/Anthra cohort: increased from 8.0 months to 9.2 months; HR, 0.64; 95% CI, 0.52 to 0.80; log-rank P < .001). No statistically significant differences in OS between the placebo- and BV-containing arms were observed. Safety was consistent with results of prior BV trials. CONCLUSION The combination of BV with Cape, Tax, or Anthra improves clinical benefit in terms of increased PFS in first-line treatment of metastatic breast cancer, with a safety profile comparable to prior phase III studies.

Randomized Phase III Study of Trastuzumab, Paclitaxel, and Carboplatin Compared With Trastuzumab and Paclitaxel in Women With HER-2–Overexpressing Metastatic Breast Cancer

PURPOSE This randomized, multicenter, phase III trial evaluated the efficacy and safety of trastuzumab and paclitaxel with or without carboplatin as first-line therapy for women with HER-2-overexpressing metastatic breast cancer (MBC). PATIENTS AND METHODS HER-2 overexpression was defined as immunohistochemical staining scores of 2+ or 3+. Between November 1998 and May 2002, 196 women with HER-2-overexpressing MBC were randomly assigned to six cycles of either trastuzumab 4 mg/kg loading dose plus 2 mg/kg weekly thereafter with paclitaxel 175 mg/m2 every 3 weeks (TP), or trastuzumab 4 mg/kg loading dose plus 2 mg/kg weekly thereafter with paclitaxel 175 mg/m2 and carboplatin area under the time-concentration curve = 6 every 3 weeks (TPC) followed by weekly trastuzumab alone. RESULTS Baseline characteristics of the 196 patients were well balanced between study arms. Objective response rate (ORR) was 52% (95% CI, 42% to 62%) for TPC versus 36% (95% CI, 26% to 46%) for TP (P = .04). Median progression-free survival (PFS) was 10.7 months for TPC and 7.1 months for TP (hazard ratio [HR], 0.66; 95% CI, 0.59 to 0.73; P = .03). Improved clinical outcomes with TPC were most evident in HER-2 3+ patients, with an ORR of 57% (95% CI, 45% to 70%) v 36% (95% CI, 25% to 48%; P = .03) and median PFS of 13.8 v 7.6 months (P = .005) for TPC and TP, respectively (HR, 0.55; 95% CI, 0.46 to 0.64). Both regimens were well tolerated, and febrile neutropenia and neurotoxicity occurred infrequently; grade 4 neutropenia occurred more frequently with TPC (P < .01). CONCLUSION The addition of carboplatin to paclitaxel and trastuzumab improved ORR and PFS in women with HER-2-overexpressing MBC. This well-tolerated regimen represents a new therapeutic option.

Factors influencing cosmetic outcome and complication risk after conservative surgery and radiotherapy for early-stage breast carcinoma.

PURPOSE The study was undertaken to assess the relationship among cosmesis and complications to factors related to disease presentation, surgical and radiotherapeutic technique, and adjuvant systemic therapy in conservative treatment for early-stage breast carcinoma. PATIENTS AND METHODS Between 1982 and 1988, 234 women with stage I/II breast carcinoma were treated with conservation therapy by a highly standardized protocol of limited excision and radiotherapy. Radiation boost and/or reexcision were determined by careful quantitation of the normal tissue margin around the primary tumor. Boosts to 20 Gy were preferentially performed with interstitial iridium-192 (192Ir) implants. Axillary node dissections were performed in all patients aged less than 70 years. Adjuvant therapy consisted of cyclophosphamide, methotrexate, (doxorubicin), and fluorouracil (CM[A]F) six to eight times for node-positive premenopausal women and tamoxifen for node-positive or -negative postmenopausal women. Median follow-up was 50 months (range, 20 to 80 months). Cosmesis was graded by defined criteria, and complications were individually scored. RESULTS Factors found to impact cosmesis adversely were palpable tumors (P = .046), volume of breast tissue resected (P = .027), reexcision of the tumor bed (P = .01), number of radiation fields (P = .03), radiation boost (P = .01), and chest wall separation (P = .01). There was a trend toward worse cosmesis (P = .062) in patients receiving tamoxifen. Cosmesis was not adversely affected by interstitial implant in spite of a higher prescribed dose. Factors influencing complication risk were axillary node dissection (P = .02), number of lymph nodes harvested (P = .05), and chemotherapy (P = .03). CONCLUSIONS Optimal cosmesis and minimal complication risk require careful attention to the technical details of surgery and radiotherapy. The impact of systemic therapies needs to be more thoroughly examined.

Consensus statement on postmastectomy radiation therapy

1. Reduction in the recurrence rate of clinically detectable local-regional disease by PMRT is evident. 2. The most recent randomized controlled trials, including two well-designed trials using modern radiation techniques, have shown a moderate and statistically significant improvement in survival. 3. Consultation with a radiation oncologist should occur in postmastectomy node-positive patients. Patients with 4 or more positive lymph nodes should receive radiation therapy to improve local control and perhaps survival as well. Greater benefit was seen in patients with 1-3 positive nodes and in patients with smaller tumor burdens. 4. In all patients, the chest wall should be treated. 5. The treatment of internal mammary nodes remains controversial. 6. A supraclavicular field can be used to encompass the axillary apex and supraclavicular area in selected node-positive patients (particularly those with 4 or more positive nodes). A posterior axillary radiation field may be considered in patients with incomplete axillary dissection. 7. Effort should be made to minimize the dose to heart and lung. 8. The optimal sequencing of chemotherapy and PMRT remains uncertain.

Assessment of Quality of Life in MA.17: A Randomized, Placebo-Controlled Trial of Letrozole After 5 Years of Tamoxifen in Postmenopausal Women

PURPOSE To evaluate the impact of letrozole compared with placebo after adjuvant tamoxifen on quality of life (QOL) in the MA.17 trial. METHODS Patients completed the Short Form 36-item Health Survey (SF-36) and the Menopause Specific Quality of Life Questionnaire (MENQOL) at baseline, 6 months, and annually. Mean change scores from baseline were compared between groups for summary measures and domains. A response analysis compared the proportion of patients who demonstrated an important change in QOL. RESULTS Of 5,187 randomly assigned women in the trial, 3,612 (69.9%) participated in the QOL substudy: 1,799 were allocated to placebo and 1,813 were allocated to letrozole. No differences were seen between groups in mean change scores from baseline for the SF-36 physical and mental component summary scores at 6, 12, 24, and 36 months. Small (< 0.2 standard deviations) but statistically significant differences in mean change scores from baseline were seen for the SF-36 domains of physical functioning (12 months), bodily pain (6 months) and vitality (6 and 12 months), and the MENQOL vasomotor (6, 12, and 24 months) and sexual domains (12 and 24 months). On the response analysis, a significant difference was seen between groups for the bodily pain domain (percentage of patients reporting a worsening of QOL, 47% placebo v 51% letrozole; P = .009) and the vasomotor domain (22% placebo v 29% letrozole; P = .001). CONCLUSION Letrozole did not have an adverse impact on overall QOL. Small effects were seen in some domains consistent with a minority of patients experiencing changes in QOL compatible with a reduction in estrogen synthesis.

Extending Aromatase-Inhibitor Adjuvant Therapy to 10 Years

BACKGROUND Treatment with an aromatase inhibitor for 5 years as up-front monotherapy or after tamoxifen therapy is the treatment of choice for hormone-receptor-positive early breast cancer in postmenopausal women. Extending treatment with an aromatase inhibitor to 10 years may further reduce the risk of breast-cancer recurrence. METHODS We conducted a double-blind, placebo-controlled trial to assess the effect of the extended use of letrozole for an additional 5 years. Our primary end point was disease-free survival. RESULTS We enrolled 1918 women. After a median follow-up of 6.3 years, there were 165 events involving disease recurrence or the occurrence of contralateral breast cancer (67 with letrozole and 98 with placebo) and 200 deaths (100 in each group). The 5-year disease-free survival rate was 95% (95% confidence interval [CI], 93 to 96) with letrozole and 91% (95% CI; 89 to 93) with placebo (hazard ratio for disease recurrence or the occurrence of contralateral breast cancer, 0.66; P=0.01 by a two-sided log-rank test stratified according to nodal status, prior adjuvant chemotherapy, the interval from the last dose of aromatase-inhibitor therapy, and the duration of treatment with tamoxifen). The rate of 5-year overall survival was 93% (95% CI, 92 to 95) with letrozole and 94% (95% CI, 92 to 95) with placebo (hazard ratio, 0.97; P=0.83). The annual incidence rate of contralateral breast cancer in the letrozole group was 0.21% (95% CI, 0.10 to 0.32), and the rate in the placebo group was 0.49% (95% CI, 0.32 to 0.67) (hazard ratio, 0.42; P=0.007). Bone-related toxic effects occurred more frequently among patients receiving letrozole than among those receiving placebo, including a higher incidence of bone pain, bone fractures, and new-onset osteoporosis. No significant differences between letrozole and placebo were observed in scores on most subscales measuring quality of life. CONCLUSIONS The extension of treatment with an adjuvant aromatase inhibitor to 10 years resulted in significantly higher rates of disease-free survival and a lower incidence of contralateral breast cancer than those with placebo, but the rate of overall survival was not higher with the aromatase inhibitor than with placebo. (Funded by the Canadian Cancer Society and others; ClinicalTrials.gov numbers, NCT00003140 and NCT00754845.).

Late Extended Adjuvant Treatment With Letrozole Improves Outcome in Women With Early-Stage Breast Cancer Who Complete 5 Years of Tamoxifen

PURPOSE The National Cancer Institute of Canada Clinical Trials Group MA.17 trial examined the efficacy of letrozole (LET) started within 3 months of 5 years of adjuvant tamoxifen in postmenopausal hormone receptor-positive early-stage breast cancer. When the trial was unblinded, patients who received placebo (PLAC) were offered LET. PATIENTS AND METHODS This cohort analysis describes the outcomes of women assigned PLAC at the initial random assignment after unblinding. Efficacy outcomes of women who chose LET (PLAC-LET group) were compared with those who did not (PLAC-PLAC group) by the hazard ratios and by P values calculated from Cox models that adjusted for imbalances between the groups. Toxicity analyses included only events that occurred after unblinding. RESULTS There were 1,579 women in the PLAC-LET group (median time from tamoxifen, 2.8 years) and 804 in the PLAC-PLAC group. Patients in the PLAC-LET group were younger; had a better performance status; and were more likely to have had node-positive disease, axillary dissection, and adjuvant chemotherapy than those in the PLAC-PLAC group. At a median follow-up of 5.3 years, disease-free survival (DFS; adjusted hazard ratio [HR], 0.37; 95% CI, 0.23 to 0.61; P < .0001) and distant DFS (HR, 0.39; 95% CI, 0.20 to 0.74; P = .004) were superior in the PLAC-LET group. More self-reported new diagnoses of osteoporosis and significantly more clinical fractures occurred in the women who took LET (5.2% v 3.1%, P = .02). CONCLUSION Interpretation of this cohort analysis suggests that LET improves DFS and distant DFS even when there has been a substantial period of time since the discontinuation of prior adjuvant tamoxifen.

Prognostic Value of Histologic Grade and Proliferative Activity in Axillary Node–Positive Breast Cancer: Results From the Eastern Cooperative Oncology Group Companion Study, EST 4189

PURPOSE The identification of a subset of patients with axillary lymph node-positive breast cancer with an improved prognosis would be clinically useful. We report the prognostic importance of histologic grading and proliferative activity in a cohort of patients with axillary lymph node-positive breast cancer and compare these parameters with other established prognostic factors. PATIENTS AND METHODS This Eastern Cooperative Oncology Group laboratory companion study (E4189) centered on 560 axillary lymph node-positive patients registered onto one of six eligible clinical protocols. Flow cytometric (ploidy and S-phase fraction [SPF]) and histopathologic analyses (Nottingham Combined Histologic Grade and mitotic index) were performed on paraffin-embedded tissue from 368 patients. RESULTS Disease recurred in 208 patients; in 161 (77%), within the first 5 years. Mitotic index and grade were associated with both ploidy and SPF (P </=.01). Within the first 5 years of follow-up, mitotic index (P =.004), grade (P =.004), ploidy (P =. 006), and SPF (P =.05) were associated with time to recurrence; there was also a significant association with survival. The effect of mitotic index was largely a result of the difference between 0 to 2 mitoses/10 high-power fields (HPF; 5-year recurrence of 31%) and more than 2 mitoses/10 HPF (5-year recurrence of 52%). The 0 to 2 mitoses/10 HPF group was independently associated with improved prognosis at 5 years (P =.002) in regression models that included other standard prognostic factors. CONCLUSION A subset of axillary lymph node-positive patients with improved prognosis may be identified using a lower (< 3 mitoses/10 HPF) mitotic count than is usually performed.