Rudolf Maibach

Adjuvant Exemestane with Ovarian Suppression in Premenopausal Breast Cancer

BACKGROUND Adjuvant therapy with an aromatase inhibitor improves outcomes, as compared with tamoxifen, in postmenopausal women with hormone-receptor-positive breast cancer. METHODS In two phase 3 trials, we randomly assigned premenopausal women with hormone-receptor-positive early breast cancer to the aromatase inhibitor exemestane plus ovarian suppression or tamoxifen plus ovarian suppression for a period of 5 years. Suppression of ovarian estrogen production was achieved with the use of the gonadotropin-releasing-hormone agonist triptorelin, oophorectomy, or ovarian irradiation. The primary analysis combined data from 4690 patients in the two trials. RESULTS After a median follow-up of 68 months, disease-free survival at 5 years was 91.1% in the exemestane-ovarian suppression group and 87.3% in the tamoxifen-ovarian suppression group (hazard ratio for disease recurrence, second invasive cancer, or death, 0.72; 95% confidence interval [CI], 0.60 to 0.85; P<0.001). The rate of freedom from breast cancer at 5 years was 92.8% in the exemestane-ovarian suppression group, as compared with 88.8% in the tamoxifen-ovarian suppression group (hazard ratio for recurrence, 0.66; 95% CI, 0.55 to 0.80; P<0.001). With 194 deaths (4.1% of the patients), overall survival did not differ significantly between the two groups (hazard ratio for death in the exemestane-ovarian suppression group, 1.14; 95% CI, 0.86 to 1.51; P=0.37). Selected adverse events of grade 3 or 4 were reported for 30.6% of the patients in the exemestane-ovarian suppression group and 29.4% of those in the tamoxifen-ovarian suppression group, with profiles similar to those for postmenopausal women. CONCLUSIONS In premenopausal women with hormone-receptor-positive early breast cancer, adjuvant treatment with exemestane plus ovarian suppression, as compared with tamoxifen plus ovarian suppression, significantly reduced recurrence. (Funded by Pfizer and others; TEXT and SOFT ClinicalTrials.gov numbers, NCT00066703 and NCT00066690, respectively.).

Adjuvant ovarian suppression in premenopausal breast cancer.

BACKGROUND Suppression of ovarian estrogen production reduces the recurrence of hormone-receptor-positive early breast cancer in premenopausal women, but its value when added to tamoxifen is uncertain. METHODS We randomly assigned 3066 premenopausal women, stratified according to prior receipt or nonreceipt of chemotherapy, to receive 5 years of tamoxifen, tamoxifen plus ovarian suppression, or exemestane plus ovarian suppression. The primary analysis tested the hypothesis that tamoxifen plus ovarian suppression would improve disease-free survival, as compared with tamoxifen alone. In the primary analysis, 46.7% of the patients had not received chemotherapy previously, and 53.3% had received chemotherapy and remained premenopausal. RESULTS After a median follow-up of 67 months, the estimated disease-free survival rate at 5 years was 86.6% in the tamoxifen-ovarian suppression group and 84.7% in the tamoxifen group (hazard ratio for disease recurrence, second invasive cancer, or death, 0.83; 95% confidence interval [CI], 0.66 to 1.04; P=0.10). Multivariable allowance for prognostic factors suggested a greater treatment effect with tamoxifen plus ovarian suppression than with tamoxifen alone (hazard ratio, 0.78; 95% CI, 0.62 to 0.98). Most recurrences occurred in patients who had received prior chemotherapy, among whom the rate of freedom from breast cancer at 5 years was 82.5% in the tamoxifen-ovarian suppression group and 78.0% in the tamoxifen group (hazard ratio for recurrence, 0.78; 95% CI, 0.60 to 1.02). At 5 years, the rate of freedom from breast cancer was 85.7% in the exemestane-ovarian suppression group (hazard ratio for recurrence vs. tamoxifen, 0.65; 95% CI, 0.49 to 0.87). CONCLUSIONS Adding ovarian suppression to tamoxifen did not provide a significant benefit in the overall study population. However, for women who were at sufficient risk for recurrence to warrant adjuvant chemotherapy and who remained premenopausal, the addition of ovarian suppression improved disease outcomes. Further improvement was seen with the use of exemestane plus ovarian suppression. (Funded by Pfizer and others; SOFT ClinicalTrials.gov number, NCT00066690.).

CYP2D6 Genotype and Tamoxifen Response in Postmenopausal Women with Endocrine-Responsive Breast Cancer: The Breast International Group 1-98 Trial

BACKGROUND Adjuvant tamoxifen therapy is effective for postmenopausal women with endocrine-responsive breast cancer. Cytochrome P450 2D6 (CYP2D6) enzyme metabolizes tamoxifen to clinically active metabolites, and CYP2D6 polymorphisms may adversely affect tamoxifen efficacy. In this study, we investigated the clinical relevance of CYP2D6 polymorphisms. METHODS We obtained tumor tissues and isolated DNA from 4861 of 8010 postmenopausal women with hormone receptor-positive breast cancer who enrolled in the randomized, phase III double-blind Breast International Group (BIG) 1-98 trial between March 1998 and May 2003 and received tamoxifen and/or letrozole treatment. Extracted DNA was used for genotyping nine CYP2D6 single-nucleotide polymorphisms using polymerase chain reaction-based methods. Genotype combinations were used to categorize CYP2D6 metabolism phenotypes as poor, intermediate, and extensive metabolizers (PM, IM, and EM, respectively; n = 4393 patients). Associations of CYP2D6 metabolism phenotypes with breast cancer-free interval (referred to as recurrence) and treatment-induced hot flushes according to randomized endocrine treatment and previous chemotherapy were assessed. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS No association between CYP2D6 metabolism phenotypes and breast cancer-free interval was observed among patients who received tamoxifen monotherapy without previous chemotherapy (P = .35). PM or IM phenotype had a non-statistically significantly reduced risk of breast cancer recurrence compared with EM phenotype (PM or IM vs EM, HR of recurrence = 0.86, 95% CI = 0.60 to 1.24). CYP2D6 metabolism phenotype was associated with tamoxifen-induced hot flushes (P = .020). Both PM and IM phenotypes had an increased risk of tamoxifen-induced hot flushes compared with EM phenotype (PM vs EM, HR of hot flushes = 1.24, 95% CI = 0.96 to 1.59; IM vs EM, HR of hot flushes = 1.23, 95% CI = 1.05 to 1.43). CONCLUSIONS CYP2D6 phenotypes of reduced enzyme activity were not associated with worse disease control but were associated with increased hot flushes, contrary to the hypothesis. The results of this study do not support using the presence or absence of hot flushes or the pharmacogenetic testing of CYP2D6 to determine whether to treat postmenopausal breast cancer patients with tamoxifen.

Successful Treatment of Childhood High-Risk Hepatoblastoma With Dose-Intensive Multiagent Chemotherapy and Surgery: Final Results of the SIOPEL-3HR Study

PURPOSE The primary objective was to determine the efficacy of a newly designed preoperative chemotherapy regimen in an attempt to improve the cure rate of children with high-risk hepatoblastoma. PATIENTS AND METHODS High risk was defined as follows: tumor in all liver sections (ie, Pretreatment Extension IV [PRETEXT-IV]), or vascular invasion (portal vein [P+], three hepatic veins [V+]), or intra-abdominal extrahepatic extension (E+), or metastatic disease, or alpha-fetoprotein less than 100 ng/mL at diagnosis. Patients were treated with alternating cycles of cisplatin and carboplatin plus doxorubicin (preoperatively, n = 7; postoperatively, n = 3) and delayed tumor resection. RESULTS Of the 151 patients (150 evaluable for response) 118 (78.7%) achieved a partial response to chemotherapy. Complete resection of the liver tumor could be achieved in 115 patients (76.2%) either by partial hepatectomy (55.6%) or by liver transplantation (20.6%). In 106 children (70.2%), complete resection of all tumor lesions (including metastases) was achieved. Among the patients with initial lung metastases, 52.2% achieved complete remission of the lung lesions with chemotherapy alone. In half of the patients with initial PRETEXT-IV tumor as the only high-risk feature, the tumor could be completely resected with partial hepatectomy. Event-free (EFS) and overall survival (OS) estimates at 3 years were 65% (95% CI, 57% to 73%) and 69% (95% CI, 62% to 77%) for the whole group. EFS and OS for all patients with PRETEXT-IV tumor were 68% and 69%, respectively, and they were 56% and 62%, respectively, for patients with metastasis. CONCLUSION The applied treatment rendered a great proportion of tumors resectable, and, in comparison with previously published results, led to an improved survival in patients with high-risk hepatoblastoma.

Cisplatin versus Cisplatin plus Doxorubicin for Standard-Risk Hepatoblastoma

BACKGROUND Preoperative cisplatin alone may be as effective as cisplatin plus doxorubicin in standard-risk hepatoblastoma (a tumor involving three or fewer sectors of the liver that is associated with an alpha-fetoprotein level of >100 ng per milliliter). METHODS Children with standard-risk hepatoblastoma who were younger than 16 years of age were eligible for inclusion in the study. After they received one cycle of cisplatin (80 mg per square meter of body-surface area per 24 hours), we randomly assigned patients to receive cisplatin (every 14 days) or cisplatin plus doxorubicin administered in three preoperative cycles and two postoperative cycles. The primary outcome was the rate of complete resection, and the trial was powered to test the noninferiority of cisplatin alone (<10% difference in the rate of complete resection). RESULTS Between June 1998 and December 2006, 126 patients were randomly assigned to receive cisplatin and 129 were randomly assigned to receive cisplatin plus doxorubicin. The rate of complete resection was 95% in the cisplatin-alone group and 93% in the cisplatin-doxorubicin group in the intention-to-treat analysis (difference, 1.4%; 95% confidence interval [CI], -4.1 to 7.0); these rates were 99% and 95%, respectively, in the per-protocol analysis. Three-year event-free survival and overall survival were, respectively, 83% (95% CI, 77 to 90) and 95% (95% CI, 91 to 99) in the cisplatin group, and 85% (95% CI, 79 to 92) and 93% (95% CI, 88 to 98) in the cisplatin-doxorubicin group (median follow-up, 46 months). Acute grade 3 or 4 adverse events were more frequent with combination therapy (74.4% vs. 20.6%). CONCLUSIONS As compared with cisplatin plus doxorubicin, cisplatin monotherapy achieved similar rates of complete resection and survival among children with standard-risk hepatoblastoma. Doxorubicin can be safely omitted from the treatment of standard-risk hepatoblastoma. (ClinicalTrials.gov number, NCT00003912.)

Hepatoblastoma with a low serum alpha-fetoprotein level at diagnosis: The SIOPEL group experience

AIM OF THE STUDY To investigate the characteristics of patients with hepatoblastoma and low serum alpha-fetoprotein (AFP) at diagnosis. PATIENTS AND METHODS Inclusion of all 21 patients accrued onto SIOPEL trials, whose serum AFP was <100ng/ml at diagnosis. Slides of all 15 patients with available histological material were centrally reviewed. RESULTS Median age: 10 months. Disease extension at diagnosis: PRETEXT group: II (3 patients), III (10 patients) and IV (8 patients). Extra-hepatic extension: 8 patients. Multifocal tumour: 8 patients. Histology at review: wholly epithelial subtype: 11/15 patients including nine with a small-cell undifferentiated histology. OUTCOME only 9 patients achieved a partial response and 16 died. Median survival: 4.4 months. Two-year overall survival: 24% (confidence interval 10-45%). CONCLUSION This study clearly identifies patients with hepatoblastoma and low serum AFP at diagnosis as a high-risk subgroup with extensive disease at diagnosis, poor response to chemotherapy and a poor outcome.

Dose-dense cisplatin-based chemotherapy and surgery for children with high-risk hepatoblastoma (SIOPEL-4): a prospective, single-arm, feasibility study

Summary Background The objective of this study was to establish the efficacy and safety of a new treatment regimen consisting of dose-dense cisplatin-based chemotherapy and radical surgery in children with high-risk hepatoblastoma. Methods SIOPEL-4 was a prospective single-arm feasibility study. Patients aged 18 years or younger with newly diagnosed hepatoblastoma with either metastatic disease, tumour in all liver segments, abdominal extrahepatic disease, major vascular invasion, low α fetoprotein, or tumour rupture were eligible. Treatment consisted of preoperative chemotherapy (cycles A1–A3: cisplatin 80 mg/m2 per day intravenous in 24 h on day 1; cisplatin 70 mg/m2 per day intravenous in 24 h on days 8, 15, 29, 36, 43, 57, and 64; and doxorubicin 30 mg/m2 per day intravenous in 24 h on days 8, 9, 36, 37, 57, and 58) followed by surgical removal of all remaining tumour lesions if feasible (including liver transplantation and metastasectomy, if needed). Patients whose tumour remained unresectable received additional preoperative chemotherapy (cycle B: doxorubicin 25 mg/m2 per day in 24 h on days 1–3 and 22–24, and carboplatin area under the curve [AUC] 10·6 mg/mL per min per day intravenous in 1 h on days 1 and 22) before surgery was attempted. After surgery, postoperative chemotherapy was given (cycle C: doxorubicin 20 mg/m2 per day in 24 h on days 1, 2, 22, 23, 43, and 44, and carboplatin AUC 6·6 mg/mL per min per day in 1 h on days 1, 22, and 43) to patients who did not receive cycle B. The primary endpoint was the proportion of patients with complete remission at the end of treatment. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00077389. Findings We report the final analysis of the trial. 62 eligible patients (39 with lung metastases) were included and analysed. 60 (98%, 95% CI 91–100) of 61 evaluable patients (one child underwent primary hepatectomy) had a partial response to preoperative chemotherapy. Complete resection of all tumour lesions was achieved in 46 patients (74%). At the end of therapy, 49 (79%, 95% CI 67–88) of 62 patients were in complete remission. With a median follow-up of 52 months, 3-year event-free survival was 76% (95% CI 65–87) and 3-year overall survival was 83% (73–93). 60 (97%) patients had grade 3–4 haematological toxicity (anaemia, neutropenia, or thrombocytopenia) and 44 (71%) had at least one episode of febrile neutropenia. Other main grade 3 or 4 toxicities were documented infections (17 patients, 27%), anorexia (22, 35%), and mucositis (seven, 11%). One child died of fungal infection in neutropenia. Moderate-to-severe ototoxicity was documented in 31 (50%) patients. 18 serious adverse events (including two deaths) reflecting the observed side-effects were reported in the trial (the most common was ototoxicity in five patients). Interpretation The SIOPEL-4 treatment regimen is feasible and efficacious for complete remission at the end of treatment for patients with high-risk hepatoblastoma. Funding Cancer Research UK and Cancer Research Switzerland/Oncosuisse.

Prognostic stratification for children with hepatoblastoma: The SIOPEL experience

PURPOSE To identify factors relevant to long-term outcome in newly diagnosed hepatoblastoma, and define subgroups for clinical research on tailoring treatment to the individual patient. PATIENTS AND METHODS Between 1995 and 2006 the SIOPEL group conducted two clinical trials which established risk-adapted therapy for hepatoblastoma patients. Patients were stratified into high-risk (AFP < 100 ng/mL and/or PRETEXT IV and/or vascular invasion and/or extra-hepatic intra-abdominal disease (V+/P+/E+) and/or metastases) and standard-risk (all others). The hierarchy of these factors plus multifocality, PRETEXT III, AFP > 1,200,000 ng/mL, patient age, platelet count and histology were further explored. The outcome measure was event-free survival (EFS). RESULTS In 541 patients, reduced EFS correlated significantly with AFP < 100 ng/ml (hazard ratio [HR] 4.09, 95% confidence interval 2.16-7.75), AFP ≥ 1.2 × 10(6)ng/mL (2.48, 1.47-4.17), metastatic disease (3.02, 2.05-4.44), PRETEXT IV (2.15, 1.19-3.87), multifocality (1.59, 1.01-2.50), age > 5 years (2.76, 1.68-4.53); borderline with small cell undifferentiated (SCU) histology (2.29, 95% confidence interval 0.91-5.77); but not with PRETEXT III, age 30-60 months, platelet count or V+/P+/E+. By using the significant factors and SCU to stratify the population, we have identified three distinct prognostic groups: PRETEXT I/II/III, and no other factors, have 3 year EFS of 90%, PRETEXT IV and/or multifocal tumour and/or age> 5 years and/or AFP > 1.2 × 10(6) have 3 year EFS of 71% and SCU and/or AFP < 100 ng/mL and/or metastatic have a 3year EFS of 49%. CONCLUSION Prognostic stratification for clinical research on newly diagnosed hepatoblastoma should take into consideration PRETEXT, metastatic disease, AFP, multifocality, age and SCU histology.

Abstract S1-8: Outcome According to CYP2D6 Genotype among Postmenopausal Women with Endocrine-Responsive Early Invasive Breast Cancer Randomized in the BIG 1-98 Trial

Background: Available endocrine therapies, tamoxifen or aromatase inhibitors (AIs), are effective on average for the large population of postmenopausal women with steroid hormone-receptor positive early breast cancer, but many patients still relapse and die of their disease. Treatment selection may be improved by determining patient and disease features that suggest one or another endocrine therapy regimen is better for the individual patient. Recent clinical studies have presented conflicting evidence about whether postmenopausal women receiving adjuvant tamoxifen who carry genetic variants associated with low or absent CYP2D6 activity have a worse disease outcome. BIG 1-98 is a double-blind randomized trial comparing five years of the AI letrozole (Letx5), tamoxifen (Tamx5) and sequences of Let and Tam as adjuvant endocrine therapy for postmenopausal women with endocrine-responsive breast cancer. BIG 1-98 enrolled 8010 patients between 1998 and 2003. Results at 6 years median follow-up showed that, on average, Let was superior to Tam for disease-free and overall survival, and for time to distant recurrence. The sequential arms (Tamx2 → Letx3; Letx2 → Tamx3 had similar results compared with Let. Genotyping is underway using DNA extracted from tumor blocks of patients in trial BIG 1-98 to elucidate genetic determinants of interindividual variability in efficacy and side effects of adjuvant endocrine therapies. We hypothesize that variants of CYP2D6 are associated with shorter breast cancer-free interval on tamoxifen monotherapy, and that the relation will not be observed with letrozole monotherapy as a control. The association with sequential therapies is unknown and will be explored. Methods: Formalin-fixed, paraffin-embedded primary tumor specimens were reviewed in the IBCSG Central Pathology Laboratory and DNA isolated from one or two 1mm cores. Single nucleotide polymorphisms (SNPs) of CYP2D6 {including CYP2D6*4, *2, *3A, *6, *7, *10, *17, *41} were genotyped on the Beckman SNPstream or the ABI 7900 TaqMan system. The association of CYP2D6 variants with breast cancer-free interval and onset of hot flashes/night sweats will be investigated. The role of adjuvant chemotherapy, which was administered in about one-third of trial patients prior to randomization to adjuvant endocrine therapy, will also be investigated. Results: At this time, CYP2D6*4 has been genotyped from FFPE material of 2000 patients, with a success rate greater than 75%. The frequency of homozygous and heterozygous CYP2D6*4 was 8% and 18%, respectively, which is in line with anticipated allele frequency in a predominantly Caucasian population. Genotyping of additional CYP2D6 alleles is ongoing for these patients, as well as full genotyping for up to another 2000 patients. Conclusions: Trial BIG 1-98 provides a large, homogeneously-treated and followed cohort of patients treated with tamoxifen and other endocrine therapy regimens with available material for genotyping. Results of CYP2D6 genotyping (8 alleles) for all available patients will be presented at the meeting. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S1-8.

Premenopausal endocrine-responsive early breast cancer: who receives chemotherapy?

BACKGROUND The role of chemotherapy in addition to combined endocrine therapy for premenopausal women with endocrine-responsive early breast cancer remains an open question, yet trials designed to answer it have repeatedly failed to adequately accrue. The International Breast Cancer Study Group initiated two concurrent trials in this population: in Premenopausal Endocrine Responsive Chemotherapy (PERCHE), chemotherapy use is determined by randomization and in Tamoxifen and Exemestane Trial (TEXT) by physician choice. PERCHE closed with inadequate accrual; TEXT accrued rapidly. METHODS From 2003 to 2006, 1317 patients (890 with baseline data) were randomly assigned to receive ovarian function suppression (OFS) plus tamoxifen or OFS plus exemestane for 5 years in TEXT. We explore patient-related factors according to whether or not chemotherapy was given using descriptive statistics and classification and regression trees. RESULTS Adjuvant chemotherapy was chosen for 64% of patients. Lymph node status was the predominant determinant of chemotherapy use (88% of node positive treated versus 46% of node negative). Geography, patient age, tumor size and grade were also determinants, but degree of receptor positivity and human epidermal growth factor receptor 2 status were not. CONCLUSIONS The perceived estimation of increased risk of relapse is the primary determinant for using chemotherapy despite uncertainties regarding the degree of benefit it offers when added to combined endocrine therapy in this population.