Retreating recurrent breast cancer with the same CMF-containing regimen used as adjuvant therapy. The International Breast Cancer Study Group.

Breast cancer metastases appearing soon after adjuvant chemotherapy (within 12 months of its completion) are usually resistant to retreatment with the same cytotoxic agents, while relapses occurring later (beyond 12 months) regress when rechallenged with the same agents, showing similar response rates observed in non-pretreated patients with advanced disease. The International Breast Cancer Study Group (IBCSG) prospectively explored the efficacy of retreatment for patients upon relapse using the same therapy administered during the adjuvant programme. 87 patients previously treated with an adjuvant CMF (cyclophosphamide, methotrexate, 5-fluorouracil) combination chemotherapy (with or without the addition of low-dose prednisone and tamoxifen), who had measurable first breast cancer relapse, usually after at least 6 months of completion of the adjuvant treatment, were treated with CMF. Pretreatment consisted of 1-3 CMF courses in 27 patients and 4 or more courses in 60 patients. 17 patients were retreated with additional tamoxifen or had tamoxifen stopped at relapse. The data of these patients are shown separately. 47 of the 86 fully evaluable patients (55%) had an objective response, which was complete in 25 (29%). The dominant metastatic type and the number of involved sites were the most important factors influencing response to retreatment. Patients with soft tissue metastases had a high response rate (36/52, 69%) compared with those who had visceral involvement (9/24, 38%) or those with bony disease (2/10, 20%) (P = 0.002). In conclusion, response rates to retreatment with CMF were similar to those expected in a non-pretreated population. The patterns of relapse and the number of metastatic sites were the most important factors predicting response to retreatment, while treatment-free interval (usually longer than 6 months due to the study design) did not influence response rates. This study supports the hypothetic effectiveness of late reintroduction of adjuvant cytotoxic therapy (prior to evidence of systemic relapse), upon which several current trials are based.

Randomized comparison of tamoxifen and two separate doses of toremifene in postmenopausal patients with metastatic breast cancer.

PURPOSE: To perform a randomized three-arm comparison of tamoxifen (TAM; 20 mg/d) and two separate doses of toremifene (TOR; 60 mg/d [TOR60] and 200 mg/d [TOR200]) in postmenopausal patients with hormone receptor-positive or -unknown metastatic breast cancer. MATERIALS AND METHODS: Six hundred forty-eight patients with hormone receptor-positive or -unknown metastatic breast cancer were randomly assigned to receive TAM (n = 215), TOR60 (n = 221), or TOR200 (n = 212). RESULTS: The combined response rates (by intent to treat) were as follows;: TAM, 44%; TOR60, 50%; and TOR200, 48%. Complete and partial response rates were as follows: TAM, 19%; TOR60, 21%, and TOR200, 23% (not statistically different). Median times to progression and overall survival were not significantly different. Adverse events (lethal, serious but nonlethal, and important but non-life-threatening) were similar in all three arms, except that patients in the TOR200 arm had a statistically significantly increased rate of nausea (37% v 26% and 26% for TOR200, TAM, and TOR60, respectively; P = .027). Quality-of-life assessments were not different among the three arms. CONCLUSION: The activity, toxicity, and side effects of TOR in postmenopausal women with hormone receptor-positive or -unknown metastatic breast cancer are similar if not equivalent to those of TAM. We detected no clear evidence of a dose-response effect for TOR. TOR60 is an effective and safe agent for the treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer and can be considered an alternative to TAM as first-line treatment for such patients.

The International (Ludwig) Breast Cancer Study Group Trials I-IV: 15 years follow-up.

BACKGROUND: Adjuvant systemic therapy prolongs disease-free and overall survival in both pre- and postmenopausal patients. Available data shown benefit from multi-agent chemotherapy, prolonged tamoxifen treatment, and ovarian ablation, and that the combination of chemo- and endocrine therapy might be advantageous. In 1978 the International (Ludwig) Breast Cancer Study Group (IBCSG) initiated four complementary randomized controlled clinical trials to evaluate the roles of chemo-endocrine combinations or endocrine therapy alone in specific populations defined by risk (for pre- and perimenopausal patients) or by age (for postmenopausal patients). The results at 10 and 13 years' median follow-up for these trials are summarized in this report and are compared to those of the Overview meta-analysis with regard to chemo-endocrine or endocrine therapy combinations. Furthermore, types of first relapses by sites and second malignant diseases are reported. PATIENTS AND METHODS: 1601 evaluable patients with node positive disease were included into the studies I-IV. In Trial I (491 premenopausal patients with 1-3 positive axillary nodes) we studied the addition of low-dose continuous prednisone (p) to a cyclophosphamide-methotrexate-fluorouracil (CMF) combination. In Trial II 327 premenopausal patients with four or more positive axillary nodes were randomized to one year CMFp or to a surgical oophorectomy followed by CMFp. In Trial III (463 postmenopausal patients 65 years old or younger), combined chemoendocrine therapy (one year of CMFp plus tamoxifen (T)) was compared to endocrine therapy (1 year of p + T) or to surgery alone. In Trial IV 320 postmenopausal patients 66 to 80 years old were treated either by surgery alone or by surgery followed by 1 year prednisone and tamoxifen. RESULTS: In Trial I the addition of prednisone allowed a higher dose of cytotoxics to be administered compared with CMF alone. Despite this increased dose intensity, 13-year disease-free survival (DFS) and overall survival (OS) were similar for the two treatment groups (49% vs. 52% DFS, 59% vs. 65% OS for CMFp vs. CMF). In Trial II the addition of surgical oophorectomy to CMFp yielded an improved outcome which approached statistical significance for the subset of 107 patients known to have estrogen receptor-positive tumors (DFS, 23% vs. 15%, p = 0.13; OS, 41% vs. 30%, p = 0.12). In Trial III combined chemoendocrine therapy improved DFS and OS compared with endocrine therapy alone (p + T) given for the same duration, or no adjuvant treatment (DFS, 35% vs. 25% vs. 14%, p < 0.0001; OS, 48% vs. 36% vs. 32%, p = 0.01). In Trial IV p + T improved DFS compared with no adjuvant therapy (27% vs. 15%, p = 0.004). Despite competing risks for this elderly population, OS was also improved but the result was not statistically significant (34% vs. 22%, p = 0.08). CONCLUSIONS: The overall results of these four trials indicate that the continuation of investigations on combined chemo-endocrine therapies is warranted. The prognosis of the patients, all node-positive, treated with the most effective adjuvant treatment is such that there is a large potential for improvement.

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.