Long-term results of International Breast Cancer Study Group Trial VIII: adjuvant chemotherapy plus goserelin compared with either therapy alone for premenopausal patients with node-negative breast cancer.

BACKGROUND: The International Breast Cancer Study Group Trial VIII compared long-term efficacy of endocrine therapy (goserelin), chemotherapy [cyclophosphamide, methotrexate and fluorouracil (CMF)], and chemoendocrine therapy (CMF followed by goserelin) for pre/perimenopausal women with lymph-node-negative breast cancer. PATIENTS AND METHODS: From 1990 to 1999, 1063 patients were randomized to receive (i) goserelin for 24 months (n = 346), (ii) six courses of 'classical' CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy (n = 360), or (iii) six courses of CMF plus 18 months goserelin (CMF→ goserelin; n = 357). Tumors were classified as estrogen receptor (ER) negative (19%), ER positive (80%), or ER unknown (1%); 19% of patients were younger than 40. Median follow-up was 12.1 years. RESULTS: For the ER-positive cohort, sequential therapy provided a statistically significant benefit in disease-free survival (DFS) (12-year DFS = 77%) compared with CMF alone (69%) and goserelin alone (68%) (P = 0.04 for each comparison), due largely to the effect in younger patients. Patients with ER-negative tumors whose treatment included CMF had similar DFS (12-year DFS CMF = 67%; 12-year DFS CMF→ goserelin = 69%) compared with goserelin alone (12-year DFS = 61%, P= NS). CONCLUSIONS: For pre/perimenopausal women with lymph-node-negative ER-positive breast cancer, CMF followed by goserelin improved DFS in comparison with either modality alone. The improvement was the most pronounced in those aged below 40, suggesting an endocrine effect of prolonged CMF-induced amenorrhea.

Differential efficacy of three cycles of CMF followed by tamoxifen in patients with ER-positive and ER-negative tumors: long-term follow up on IBCSG Trial IX.

BACKGROUND: The benefit of adjuvant chemotherapy in postmenopausal patients with estrogen receptor (ER)-positive lymph node-negative breast cancer is being reassessed. PATIENTS AND METHODS: After stratification by ER status, 1669 postmenopausal patients with operable lymph node-negative breast cancer were randomly assigned to three 28-day courses of 'classical' CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy followed by tamoxifen for 57 months (CMF→tamoxifen) or to tamoxifen alone for 5 years. RESULTS: ERs were positive in 81% of tumors. At a median follow-up of 13.1 years, patients with ER-positive breast cancers did not benefit from CMF [13-year disease-free survival (DFS) 64% CMF→tamoxifen, 66% tamoxifen; P = 0.99], whereas CMF substantially improved the prognosis of patients with ER-negative breast cancer (13-year DFS 73% versus 57%, P = 0.001). Similarly, breast cancer-free interval (BCFI) was identical in the ER-positive cohort but significantly improved by chemotherapy in the ER-negative cohort (13-year BCFI 80% versus 63%, P = 0.001). CMF had no influence on second nonbreast malignancies or deaths from other causes. CONCLUSION: CMF is not beneficial in postmenopausal patients with node-negative ER-positive breast cancer but is highly effective within the ER-negative cohort. In the future, other markers of chemotherapy response may define a subset of patients with ER-positive tumors who may benefit from adjuvant chemotherapy.

Adverse prognostic value of peritumoral vascular invasion: is it abrogated by adequate endocrine adjuvant therapy? Results from two International Breast Cancer Study Group randomized trials of chemoendocrine adjuvant therapy for early breast cancer.

BACKGROUND: Peritumoral vascular invasion (PVI) may assist in assigning optimal adjuvant systemic therapy for women with early breast cancer. PATIENTS AND METHODS: Patients participated in two International Breast Cancer Study Group randomized trials testing chemoendocrine adjuvant therapies in premenopausal (trial VIII) or postmenopausal (trial IX) node-negative breast cancer. PVI was assessed by institutional pathologists and/or central review on hematoxylin-eosin-stained slides in 99% of patients (analysis cohort 2754 patients, median follow-up >9 years). RESULTS: PVI, present in 23% of the tumors, was associated with higher grade tumors and larger tumor size (trial IX only). Presence of PVI increased locoregional and distant recurrence and was significantly associated with poorer disease-free survival. The adverse prognostic impact of PVI in trial VIII was limited to premenopausal patients with endocrine-responsive tumors randomized to therapies not containing goserelin, and conversely the beneficial effect of goserelin was limited to patients whose tumors showed PVI. In trial IX, all patients received tamoxifen: the adverse prognostic impact of PVI was limited to patients with receptor-negative tumors regardless of chemotherapy. CONCLUSION: Adequate endocrine adjuvant therapy appears to abrogate the adverse impact of PVI in node-negative disease, while PVI may identify patients who will benefit particularly from adjuvant therapy.

Timing of CMF chemotherapy in combination with tamoxifen in postmenopausal women with breast cancer: role of endocrine responsiveness of the tumor.

BACKGROUND: Controversy persists about whether chemotherapy benefits all breast cancer patients. PATIENTS AND METHODS: In the International Breast Cancer Study Group (IBCSG) trial VII, 1212 postmenopausal patients with node-positive disease were randomized to receive tamoxifen for 5 years or tamoxifen plus three concurrent courses of cyclophosphamide, methotrexate and 5-fluorouracil ('classical' CMF) chemotherapy, either early, delayed or both. In IBCSG trial IX, 1669 postmenopausal patients with node-negative disease were randomized to receive either tamoxifen alone or three courses of adjuvant classical CMF prior to tamoxifen. Results were assessed according to estrogen receptor (ER) content of the primary tumor. RESULTS: For patients with node-positive, ER-positive disease, adding CMF either early, delayed or both reduced the risk of relapse by 21% (P=0.06), 26% (P=0.02) and 25% (P=0.02), respectively, compared with tamoxifen alone. There was no difference in disease-free survival when CMF was given prior to tamoxifen in patients with node-negative, ER-positive tumors. CONCLUSIONS: CMF given concurrently (early, delayed or both) with tamoxifen was more effective than tamoxifen alone for patients with node-positive, endocrine-responsive breast cancer, supporting late administration of chemotherapy even after commencement of tamoxifen. In contrast, sequential CMF and tamoxifen for patients with node-negative, endocrine-responsive disease was ineffective.

Burdens and benefits of adjuvant cyclophosphamide, methotrexate, and fluorouracil and tamoxifen for elderly patients with breast cancer: the International Breast Cancer Study Group Trial VII.

PURPOSE: Information on the tolerability and efficacy of adjuvant chemoendocrine therapy for older women is limited. We studied these issues using the data collected as part of the International Breast Cancer Study Group Trial VII. PATIENTS AND METHODS: Postmenopausal women with operable, node-positive breast cancer were randomized to receive either tamoxifen alone for 5 years (306 patients) or tamoxifen plus three consecutive cycles of classical cyclophosphamide (100 mg/m(2) orally days 1 to 14), methotrexate (40 mg/m(2) intravenous days 1 and 8), and fluorouracil (600 mg/m(2) intravenous days 1 and 8) every 28 days (CMF; 302 patients). The median follow-up was 8.0 years. RESULTS: Among the 299 patients who received at least one dose of CMF, women 65 years of age or older (n = 76) had higher grades of toxicity compared with women less than 65 years old (n = 223) (P =.004). More women in the older age group compared with the younger women experienced grade 3 toxicity of any type (17% v 7%, respectively), grade 3 hematologic toxicity (9% v 5%, respectively), and grade 3 mucosal toxicity (4% v 1%, respectively). Older patients also received less than their expected CMF dose compared with younger postmenopausal women (P =.0008). The subjective burdens of treatment, however, were similar for younger and older patients based on quality-of-life measures (performance status, coping, physical well-being, mood, and appetite). For older patients, the 5-year disease-free survival (DFS) rates were 63% for CMF plus tamoxifen and 61% for tamoxifen alone (hazards ratio [HR], 1.00; 95% confidence interval [CI], 0.65 to 1.52; P =.99). For younger patients, the corresponding 5-year DFS rates were 61% and 53% (HR, 0.70; 95% CI, 0.53 to 0.91; P =.008), but the test for heterogeneity of CMF effect according to age group was not statistically significant. The reduced effectiveness of CMF among older women could not be attributed to dose reductions according to dose received. CONCLUSION: CMF tolerability and effectiveness were both reduced for older patients compared with younger postmenopausal node-positive breast cancer patients who received tamoxifen for 5 years. The development and evaluation of less toxic and more effective chemotherapy regimens are required for high-risk elderly patients.

Mortality during adjuvant treatment of early breast cancer with cyclophosphamide, methotrexate, and fluorouracil. International Breast Cancer Study Group.

Combined chemotherapy for early breast cancer with cyclophosphamide, methotrexate, and fluorouracil has low associated mortality, but related deaths were seen among women aged 65 years or older in International Breast Cancer Study Group trials.

The effect of adjuvant prednisone combined with CMF on patterns of relapse and occurrence of second malignancies in patients with breast cancer. International (Ludwig) Breast Cancer Study Group.

BACKGROUND: The addition of low-dose prednisone (p) to the adjuvant regimen of cyclophosphamide, methotrexate, 5-fluorouracil (CMF) allowed patients to receive a larger dose of cytotoxics when compared with those on CMF alone. However, disease-free survival and overall survival were similar for the two groups. To test the hypothesis that low-dose prednisone might influence the efficacy of the cytotoxic regimen used, the toxicity profiles of the two treatment regimens and the patterns of treatment failure (relapse, second malignancy, or death) were examined. PATIENTS AND METHODS: 491 premenopausal and perimenopausal patients with one to three positive axillary lymph nodes included in International (Ludwig) Breast Cancer Study Group (IBCSG) trial I from 1978 to 1981 and randomized to receive CMF or CMFp were analyzed for differences in long-term outcome and toxic events. The 250 patients assigned to CMF and prednisone received on the average 12% more cytotoxic drugs than those who received CMF alone. RESULTS: The 13-year DFS for the CMFp group was 49% as compared to 52% for CMF alone, and the respective OS percents were 59% and 65%. Several toxic effects such as leukopenia, alopecia, mucositis and induced amenorrhea were reported at a similar incidence in the two treatment groups. Using cumulative incidence methodology for competing risks, we detected a statistically significant increase in first relapse in the skeleton for the CMFp group at 13 years follow-up with a relative risk (RR) of 2.06 [95% confidence interval (CI), 1.23 to 3.46; P = 0.004]. Patients with larger tumors in the CMFp regimen were especially subject to this increase with a RR for failure in the skeleton of 3.32 (95% CI, 1.57 to 7.02; P = 0.0005). CMFp-treated patients also had a larger proportion of second malignancies (not breast cancer), with RR of 3.34 (95% CI, 0.91 to 12.31; P = 0.09). CONCLUSIONS: Low-dose continuous prednisone added to adjuvant CMF chemotherapy enabled the use of higher doses of cytotoxics. This increased dose had no beneficial effect on treatment outcome, but was associated with an increased risk for bone relapses and a small, not statistically significant increased incidence of second malignancies. The effects of steroids, which are widely used as antiemetics (oral or pulse injection) together with cytotoxics, should be investigated to identify their influence upon treatment outcome.

Effect of systemic adjuvant treatment on first sites of breast cancer relapse.

Adjuvant systemic treatment for resectable breast cancer changes the natural history of the disease but provides only a small and delayed effect on survival. Evaluation of the types of first relapse avoided by available treatments may explain why effects on mortality are small and appear late during follow-up. In randomised clinical trials done by the International Breast Cancer Study Group (IBCSG) between 1978 and 1985, 2108 patients with node-positive disease received more-effective treatments (6 or more cycles of cyclophosphamide, methotrexate, fluorouracil and prednisone; with or without tamoxifen, or tamoxifen and prednisone alone), and 722 patients received less-effective treatments (no treatment or a single cycle of chemotherapy). 3 main categories of first site of relapse were defined and evaluated by cumulative incidence analysis: local or regional, and distant soft tissue, bone, and viscera. The more-effective treatments reduced the cumulative incidence of first relapse in local or regional and distant soft tissue sites at 10 years from 36% to 18% (p = 0.0001); first relapse in bone and viscera was not altered by the more-effective treatments. These results were similar for premenopausal and postmenopausal women, and for patients with oestrogen-receptor-positive or oestrogen-receptor-negative tumours. Adjuvant systemic treatments in current use improve patient outcome mainly by reducing the incidence of first local or regional and distant soft-tissue relapses, while first recurrences in bone or viscera are influenced much less. More intensive treatments at present being tested in clinical trials might affect bone and visceral relapses and have a greater and earlier influence on survival.