A Gynecologic Oncology Group study of frequent copy number aberrations in DNA repair genes and other genomic regions in stage I serous ovarian cancers

e16504

Background: A proof of principle array-based comparative genomic hybridization (aCGH) analysis was performed in archival formalin-fixed and paraffin-embedded (FFPE) stage I ovarian cancers (EOC) to determine if frequent (>40%) copy number aberrations (CNAs) can be detected in DNA repair genes including the Fanconi anemia complementation group (FANC) and RAD51 families compared with the rest of the genome. Methods: Tumor DNA was isolated from 22 serous cancers from the GOG-175 virtual tissue bank. RPCI 19K BAC arrays were hybridized (GeneTAC HybStation) and scanned (Gene Pix 4200AL Laser Scanner). Spot fluorescence values were quantified using ImaGene, vetted for quality and loess corrected with adjustments for chip-specific spatial effects. The genome was segmented to identify regions with common copy number means (DNAcopy software). Posterior aberration probabilities for the regions were obtained using CGHcall and data was visualized and annotated using iGenomicViewer in R. Results: Several genes associated with the Fanconi DNA-damage response pathway were frequently altered in stage I serous ovarian carcinomas. A RAD51 homology DMC1 was amplified in 55% of the specimens. Genomic losses were observed in FANC-D1 (BRCA2), and RAD51L3 in 41%, and 27% of specimens, respectively. In contrast, frequent genomic losses or gains involved 13q33.1; 13 q21.31; 17p12; 17q22; 18q12.3; 9p11.2; 9p22.2–22.3; 9q33.1; 8p23.2; 21q21.3; and 5q14.2; or 8q24.3; 3q29; 12p11.1; 17q25.1; 17q25.3; 20q13.33; 20q11.21; 20q11.23; 19p13.13; and 19p13.2, respectively. Conclusions: The GOG-0175 virtual tissue bank yielded high quality DNA for detecting and mapping CNAs in archival FFPE specimens with high resolution. Frequent genomic losses and gains were observed in DNA repair genes and other genomic regions in stage I serous ovarian cancer which may promote genomic instability, resistance, metastasis and aggressiveness of this disease.

No significant financial relationships to disclose.

Effect of adjuvant chemotherapy on bone resorption marker beta C-telopeptide (B-CTX) in postmenopausal women

594

Background: In NCIC CTG MA.14, a randomized trial of tamoxifen versus tamoxifen + octreotide LAR, we found a measure of bone resorption, serum B-CTx, to be significantly associated with bone-only first recurrence. Administration of chemotherapy was permitted, and chemotherapy was a stratification factor (never, concurrent, sequential). It was unclear whether pretrial B-CTx serum levels would be affected by prior administration of chemotherapy, and whether timing of chemotherapy was associated with who had bone only, or bone and other site relapse. Methods: Serum B-CTx concentration (Serum CrossLaps Nordic Biosciences, Copenhagen, DN) was determined pretrial therapy in 621 of 667 primary breast cancer patients on MA.14. We tested for differences in continuous B-CTx levels in those who had assessment before (any) chemotherapy (included those who had none) versus those who were assessed after chemotherapy with an ANOVA test. We also used exact Fisher tests to examine whether there was an association between timing of (any) chemotherapy and 1) B-CTx values in upper 2.5% range for healthy pre-menopausal women; 2) bone only recurrence; and 3) concurrent bone and other relapse. Results: Serum B-CTx was assessed before (any) chemotherapy on 382/621 (61.5%) of patients, and after chemotherapy on 239/621 (38.5%). There were no significant differences in serum B-CTx values (p = 0.27). We found 92/621 (14.8%) of patients had high serum B-CTx levels compared with healthy pre-menopausal women; similar proportions of these women received chemotherapy after B-CTx assessment (p = 0.42). Furthermore, there were no differences in timing of (any) chemotherapy and those who had bone only recurrence (p = 0.48) or bone and other type of relapse (p = 0.76). Conclusions: Chemotherapy in the adjuvant setting had no significant effect on bone resorption marker B-CTX serum levels.

No significant financial relationships to disclose.

K-ras mutations and benefit from cetuximab in advanced colorectal cancer

BACKGROUND

Treatment with cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, improves overall and progression-free survival and preserves the quality of life in patients with colorectal cancer that has not responded to chemotherapy. The mutation status of the K-ras gene in the tumor may affect the response to cetuximab and have treatment-independent prognostic value.

METHODS

We analyzed tumor samples, obtained from 394 of 572 patients (68.9%) with colorectal cancer who were randomly assigned to receive cetuximab plus best supportive care or best supportive care alone, to look for activating mutations in exon 2 of the K-ras gene. We assessed whether the mutation status of the K-ras gene was associated with survival in the cetuximab and supportive-care groups.

RESULTS

Of the tumors evaluated for K-ras mutations, 42.3% had at least one mutation in exon 2 of the gene. The effectiveness of cetuximab was significantly associated with K-ras mutation status (P=0.01 and P<0.001 for the interaction of K-ras mutation status with overall survival and progression-free survival, respectively). In patients with wild-type K-ras tumors, treatment with cetuximab as compared with supportive care alone significantly improved overall survival (median, 9.5 vs. 4.8 months; hazard ratio for death, 0.55; 95% confidence interval [CI], 0.41 to 0.74; P<0.001) and progression-free survival (median, 3.7 months vs. 1.9 months; hazard ratio for progression or death, 0.40; 95% CI, 0.30 to 0.54; P<0.001). Among patients with mutated K-ras tumors, there was no significant difference between those who were treated with cetuximab and those who received supportive care alone with respect to overall survival (hazard ratio, 0.98; P=0.89) or progression-free survival (hazard ratio, 0.99; P=0.96). In the group of patients receiving best supportive care alone, the mutation status of the K-ras gene was not significantly associated with overall survival (hazard ratio for death, 1.01; P=0.97).

CONCLUSIONS

Patients with a colorectal tumor bearing mutated K-ras did not benefit from cetuximab, whereas patients with a tumor bearing wild-type K-ras did benefit from cetuximab. The mutation status of the K-ras gene had no influence on survival among patients treated with best supportive care alone. (ClinicalTrials.gov number, NCT00079066.)

Prognostic significance of defective mismatch repair and BRAF V600E in patients with colon cancer

PURPOSE

Colon tumors with defective DNA mismatch repair (dMMR) have a well-characterized phenotype and accounts for approximately 15% to 20% of sporadic colon cancer as well as those colon cancer patients with Lynch syndrome. Although the presence of dMMR seems to be a favorable prognostic marker, data suggest that these patients do not respond as well to adjuvant chemotherapy.

EXPERIMENTAL DESIGN

In this study, we examined the prognostic significance of tumor MMR deficiency and the presence of a specific mutation in BRAF (V600E) in a group of patients (n = 533) who participated in a randomized prospective clinical trial through the North Central Cancer Treatment Group.

RESULTS

Tumors with dMMR were found to be associated with higher tumor grade (P = 0.001), proximal location (P < 0.0001), and improved overall and disease-free survival (P = 0.05 and 0.04, respectively). Among all cases examined, evaluation of the BRAF V600E mutation status revealed no statistically significant differences in either disease-free or overall survival. Patients were then grouped into four categories for further analysis: dMMR/BRAF(-), dMMR/BRAF(+), pMMR/BRAF(-), and pMMR/BRAF(+). The dMMR/BRAF(-) group had a significantly improved overall survival (5-year overall survival of 100% versus 73%, P = 0.002) compared with all others. The remaining three groups had very similar survival outcomes. An additional cohort of tumors previously classified as having dMMR were also tested for the BRAF V600E alteration. Results remained significant (P = 0.006) when the two groups were combined for analysis.

CONCLUSIONS

Overall, these data suggest that the underlying molecular etiology of those tumors having dMMR may influence the disease outcome in these patients.

Competing causes of death from a randomized trial of extended adjuvant endocrine therapy for breast cancer

BACKGROUND

Older women with early-stage breast cancer experience higher rates of non-breast cancer-related death. We examined factors associated with cause-specific death in a large cohort of breast cancer patients treated with extended adjuvant endocrine therapy.

METHODS

In the MA.17 trial, conducted by the National Cancer Institute of Canada Clinical Trials Group, 5170 breast cancer patients (median age = 62 years; range = 32-94 years) who were disease free after approximately 5 years of adjuvant tamoxifen treatment were randomly assigned to treatment with letrozole (2583 women) or placebo (2587 women). The median follow-up was 3.9 years (range 0-7 years). We investigated the association of 11 baseline factors with the competing risks of death from breast cancer, other malignancies, and other causes. All statistical tests were two-sided likelihood ratio criterion tests.

RESULTS

During follow-up, 256 deaths were reported (102 from breast cancer, 50 from other malignancies, 100 from other causes, and four from an unknown cause). Non-breast cancer deaths accounted for 60% of the 252 known deaths (72% for those > or = 70 years and 48% for those < 70 years). Two baseline factors were differentially associated with type of death: cardiovascular disease was associated with a statistically significant increased risk of death from other causes (P.002), and osteoporosis was associated with a statistically significant increased risk of death from other malignancies (P.05). An increased risk of breast cancer-specific death was associated with lymph node involvement (P < .001). Increased risk of death from all three causes was associated with older age (P < .001).

CONCLUSIONS

Non-breast cancer-related deaths were more common than breast cancer-specific deaths in this cohort of 5-year breast cancer survivors, especially among older women.

Randomized trial of high-dose chemotherapy with autologous peripheral-blood stem-cell support compared with standard-dose chemotherapy in women with metastatic breast cancer: NCIC MA.16

PURPOSE

We conducted a multicenter, randomized trial to compare progression-free survival (PFS), overall survival (OS), and quality of life in women with metastatic breast cancer (MBC) receiving high-dose chemotherapy plus autologous stem-cell transplantation (ASCT; HDCT) compared with standard-dose therapy.

PATIENT AND METHODS

Between April 1997 and December 2000, 386 women with MBC and no prior chemotherapy for metastatic disease were registered. After initial response to anthracycline- or taxane-based induction chemotherapy, 224 patients were randomly assigned: 112 to high-dose cyclophosphamide, mitoxantrone, and carboplatin chemotherapy and ASCT (HDCT), and 112 to standard therapy (ST). Median age was 47 years (range, 25 to 67 years). Thirty two percent of women randomly assigned had estrogen and progesterone receptor-negative breast cancer, 42% had visceral metastases, and 58% had bone metastases. Complete remission rates before random assignment were 11% for those receiving HDCT and 12% for those receiving ST.

RESULTS

After a median follow-up of 48 months, 79 deaths were observed in the HDCT arm and 77 deaths were observed in the ST arm; seven patients (6%) in the HDCT arm died as a result of toxicity. The median OS was 24 months for the HDCT arm (95% CI, 21 to 35 months) and 28 months for ST (95% CI, 22 to 33 months; hazard ratio [HR], 0.9; 95% CI, 0.6 to 1.2; P = .43). PFS was 11 months for HDCT and 9 months for ST (HR, 0.6 in favor of HDCT; 95% CI, 0.5 to 0.9; P = .006).

CONCLUSION

HDCT did not improve OS in women with MBC when used as consolidation after response to induction chemotherapy.

A dose escalation trial of adjuvant cyclophosphamide and epirubicin in combination with 5-fluorouracil using G-CSF support for premenopausal women with breast cancer involving four or more positive nodes

BACKGROUND

Dose-dense and dose-intensive regimens have improved the outcome of breast cancer in high-risk women with operable disease.

PATIENTS AND METHODS

Sixty-three premenopausal women with Stage 2, 3 breast cancer and > or =4 positive axillary nodes were treated in three successive cohorts with 70 mg/m(2) of epirubicin, 500 mg/m(2) of 5-fluorouracil and G-CSF every 14 days for 12 cycles. Cyclophosphamide (C) was given at 700 mg/m(2), 900 mg/m(2), and 1100 mg/m(2) doses. Patients were evaluated for dose-limiting toxicities (DLTs) in the first four cycles, the primary endpoint of the trial.

RESULTS

No DLTs were seen at C 700 mg/m(2); at C 900 mg/m(2) two of 16 patients experienced febrile neutropenia and poor performance status; at C 1100 mg/m(2), 1 of 31 patients experienced poor performance status. Over 6 months, febrile neutropenia, grade 4 thrombocytopenia, grade 3 anemia and severe fatigue were observed. Clinical congestive heart failure occurred in three patients over 4 years.

CONCLUSION

A dose-intense and dose-dense regimen of cyclophosphamide, epirubicin and 5-fluorouracil was delivered with G-CSF without apparent increase in acute toxicity. Cyclophosphamide could be increased to more than twice the standard dose at the cost of more anemia and fatigue.

Competing causes of death in NCIC CTG MA.17, a placebo-controlled trial of letrozole as extended adjuvant therapy for breast cancer patients

540

Background: Risk of death from other malignancies (OM) and other causes (OC) than breast cancer (BC) increases with age. Effects of baseline factors on type of death were assessed with competing risks analyses. Methods: In NCIC CTG MA.17, 5,187 women free of recurrent breast cancer after 5 years of tamoxifen were randomized to letrozole (L, 2,593 women) or placebo (P, 2,594 women). The primary endpoint was disease free survival (DFS), and secondary, overall survival (OS). Follow-up was to October 9, 2005: median 3.9 years, range <0.1 to 7.0 years. Effects of competing risks were examined for endpoints of BC, OM, and OC for 11 baseline trial factors: treatment, age, menopausal status, duration of prior tamoxifen, adjuvant radiotherapy, bone fracture, osteoporosis, cardiovascular disease, hormone receptor status, nodal status, adjuvant chemotherapy. Lagakos’ hierarchical method (Lagakos, Appl. Statist. 1978; 27:235–241) was used to test for differential effects of baseline factors on type of death (BC, OM, OC). Results: Rate of censoring was 97.8%, with 256 deaths (BC, 102; OM, 50; OC, 100; unknown, 4). Non-breast cancer deaths accounted for 60% of known deaths; 72%, for those ≥70 years; and 48%, for those <70 years. Two baseline factors differentially affected type of death. Women with cardiovascular disease were more likely to die from OC (p=0.02), while those with osteoporosis were more likely to die of OM (p=0.03). Age and nodal status had directionally similar effects. Older women had shorter survival from all 3 causes of death (p=0.01). Lymph node positivity was associated with worse survival (p=0.003). Conclusions: Extended L provides similar proportional benefit in improving DFS for all ages of women (Muss ref abstract SABCS 2006). However, the magnitude of competing non-breast cancer, and non-treatment related, causes of death needs to be considered more frequently, since with early detection and improved therapies, breast cancer patients may increasingly be expected to survive their disease to die from another cause. The novel association between baseline osteoporosis and other malignancies is being explored quantitatively.

No significant financial relationships to disclose.

Tamoxifen (T) compared to placebo (P), after adjuvant chemotherapy (CT), in premenopausal women with early breast cancer (EBC): Interim results of NCIC-CTG MA.12

547

Background: In the early 1990’s, the role of adjuvant T in premenopausal women with EBC had not been clearly established. The efficacy of adjuvant T in hormone receptor (H) negative EBC was unclear. Methods: Eligible premenopausal women with node (N) +ve/high risk N -ve EBC, any H status, post surgery, received standard adjuvant CT (AC ×4, CMF ×6, CEF x6) then were randomized to T (20 mg/day) or P for 5 yrs. Overall survival (OS), disease-free survival (DFS) and toxicity/compliance were evaluated. Original sample size was 800 pts but based on slow accrual was reduced to 660. Mortality rate is lower than anticipated, and Data Safety Monitoring Committee approved reporting results after second interim analysis (152 deaths). Results: 1993–2000, 672 women randomized, median follow-up 8.4 yrs. For T vs P, 5 yr OS 87% vs 82% [Hazard Ratio HR 0.81 (95% CI 0.58–1.12), p = 0.19] and 5 yr DFS 78% vs 71% [HR 0.79 (95% CI 0.61–1.03), p = 0.09]. HR for OS (0.87 vs 0.78, p = 0.71) and DFS (0.79 vs 0.77, p = 0.87) were not significantly different for H +ve and H -ve tumors respectively. Compliance with T/P was suboptimal, 29% women stopping treatment within 2 yrs, and only 53% completing 5 yrs. Conclusions: Current results show only a trend towards improved DFS for premenopausal women with EBC who receive T after adjuvant CT. Other studies of similar design have shown improved DFS, but not OS, and meta-analysis may be more informative. Issues affecting results (slow accrual, improved outcomes for EBC, poor compliance, additional therapies) will be discussed.

[Table: see text]

[Table: see text]

Decision making in adjuvant trials in breast cancer: the NCIC CTG MA.17 trial as an example

Decision-making regarding early closure and reporting of clinical trial results became a topic of intense debate following the reporting of the MA.17 adjuvant endocrine therapy trial. This trial was terminated at the first planned interim analysis when a highly significant improvement in disease free survival (DFS) was found. It has been suggested that the criterion for early stopping be made stricter when DFS is the primary study endpoint by ensuring that the targeted effect size is excluded. Our purpose is to examine this approach and to determine whether applying such a criterion would have affected the decision to terminate MA17. The sample size assumptions and the interim analysis of MA17 were reviewed and an appropriate method employed to convert hazard ratios (HR) to absolute differences. Expressed in relative terms, the effect size of MA17 was an HR of 0.78, and the upper boundary (0.75) of the confidence limits around the observed HR (0.57) excluded this value. In absolute terms, the lower confidence limit (3.1%) of best estimate of the 4 year difference in DFS (5.4%) excludes the difference (2.5%) used in the calculation of the targeted HR. We conclude that although the decision to release the results of the interim analysis of MA17 and allow patients on placebo to take letrozole was justified, methods for analyzing and interpreting interim results can be improved.

Randomized clinical trial of high-dose levamisole combined with 5-fluorouracil and leucovorin as surgical adjuvant therapy for high-risk colon cancer

BACKGROUND

Levamisole combined with 5-fluorouracil (5-FU) was previously shown to significantly reduce tumor relapses and improve patient survival when given postoperatively in patients with resected stage III colon cancer. Laboratory investigations subsequently documented a direct dose-dependent enhancement of 5-FU cytotoxicity with increasing concentrations of levamisole against human cancer cell lines. A clinical trial was designed to test the value of levamisole given at its maximum tolerated dose in combination with 5-FU-based chemotherapy.

PATIENTS AND METHODS

Eight hundred seventy-eight patients who had undergone complete surgical resection of high-risk stage II/III colon cancer were stratified by known prognostic factors and randomized to receive 1 of 2 treatment regimens: standard-dose levamisole combined with 5-FU and leucovorin; or high-dose levamisole combined with the same chemotherapy. Serum neopterin was monitored in a cohort of patients to evaluate immune function.

RESULTS

Severe vomiting and neurologic side effects required reduction in the dose of levamisole that could be safely administered on the high-dose levamisole regimen. There were no significant differences in disease-free survival, overall survival, or levels of serum neopterin between the treatment regimens.

CONCLUSION

It was not possible to improve the efficacy of surgical adjuvant chemotherapy for patients with high-risk colon cancer by giving levamisole at its maximum tolerated dose in combination with 5-FU and leucovorin. High rates of severe gastrointestinal and neurologic side effects were observed with the high-dose levamisole regimen.

NCIC CTG MA.17: Intent to treat analysis (ITT) of randomized patients after a median follow-up of 54 months

549

Background: MA.17 evaluated letrozole (LET) or placebo (PLAC) after 5 years of tamoxifen (Tam) and showed [median follow-up 30 months (mos)] significant improvement in disease-free survival (DFS) for LET [hazard ratio (HR) 0.57, p = 0.00008]. The trial was unblinded and PLAC patients (pts) were offered LET. An ITT analysis of all outcomes, before and after unblinding, based on the original randomization was performed. Methods: A stratified log-rank test was used to compare DFS, distant (D)DFS, overall survival (OS) and incidence of contra-lateral breast cancer (CBC). The Cox regression model used baseline stratification variables and two prespecified factors, menopausal status at the start of Tam and time on Tam. Subgroup analyses for DFS and OS were performed for the two prespecified subsets. All p-values were two-sided Results: 5187 pts were randomized at baseline and, at unblinding, 1655 of 2268 PLAC pts accepted LET. At median follow-up of 54 mos (range,16–86) 363 recurrences or CBC’s (144 LET and 219 PLAC) occurred; 118 LET and 176 PLAC pts had recurrent disease and 26 LET and 43 PLAC pts had CBC. 4 year DFS was 94.3% (LET) and 91.4% (PLAC) (HR 0.64; 95% CI, 0.52 - 0.79; p = 0.00002). Corresponding 4 year DDFS was 96.2% and 94.9% (HR 0.76; 0.58–0.99; p = 0.041). 4 year OS was 95.0% (LET) and 95.1% (PLAC) (HR 1.00; 0.78–1.28; p = 0.99). LET was equally effective in node +ve and -ve pts (i.e., similar HRs) in DFS. OS was not significantly different for LET and PLAC in any subgroup. The annual rate of CBC was 0.29% LET (0.18–0.40) and 0.47% PLAC (0.34–0.61); HR 0.61 (0.38–0.98) p = 0.037. 255 pts had died as of the data cut-off (128 LET and 127 PLAC). Conclusions: In this ITT analysis, pts originally randomized to LET within 3 months of stopping Tam did better than PLAC pts in DFS, DDFS and CBC, despite 73% of PLAC pts crossing to LET after unblinding. This highlights the strong beneficial effect of extended adjuvant therapy with LET.

[Table: see text]

Updated analysis of NCIC CTG MA.17 (letrozole vs. placebo to letrozole vs placebo) post unblinding

550

Background: 5187 postmenopausal women were originally randomized to NCIC CTG MA.17 to receive letrozole (LET) or placebo (PLAC) after 5 years of tamoxifen. The hazard ratio (HR) for disease-free survival (DFS) was 0.58 (0.450.76, p=0.00004) after a median follow-up of 30 months (mo). The trial was unblinded in October 2003 after the first interim analysis. Women randomized to PLAC were offered LET at the time of unblinding. The goal of this analysis was to determine whether women switching from PLAC to LET benefit in terms of disease outcome and to evaluate treatment related toxicities. Methods: LET and PLAC-LET have been compared to PLAC, based on the hazard ratio and adjusting for baseline patient and disease variables including, among others, tumor size, nodal status and prior adjuvant chemotherapy. Results: Information about their follow-up treatment after unblinding was available on 2268 women originally assigned to PLAC and who were free of recurrence and alive at the time of unblinding. Among them, 1655 crossed over from PLAC to LET while 613 elected no treatment. With 54 mo f/up the HR for DFS was 0.31 (0.18, 0.55: p<0.0001) favoring patients who crossed over to LET compared to those who stayed on no treatment. The treatment switch was well tolerated with no significant difference in bone fractures or cardiovascular events. An updated analysis of DFS, DDFS and OS by nodal and tumor receptor status, prior chemotherapy, menopausal status at the start of tamoxifen, and duration of prior tamoxifen therapy will be presented at the meeting. Conclusion: Women with hormone dependent breast cancer prescribed LET after a prolonged delay from completing tamoxifen experienced a significant improvement in outcome (DFS, DDFS, OS) and should be considered for this therapy.

[Table: see text]

Insulin resistance, estimated by serum C-peptide level, is associated with reduced event-free survival for postmenopausal women in NCIC CTG MA.14 adjuvant breast cancer trial

524

Background: NCIC CTG MA.14 is a randomized multi-centre trial of tamoxifen versus combined tamoxifen and octreotide LAR therapy in the adjuvant treatment of breast cancer in post-menopausal women. Planned secondary analyses included investigation of baseline metabolic factors that might influence survival. Laboratory and clinical studies indicate that insulin resistance is associated with adverse outcome in breast cancer. Insulin resistance elevates C-peptide levels. Methods: In MA.14, trial patients with stage I or II postmenopausal breast cancer were randomized from September, 1996 until July, 2000 to receive 20 mg tamoxifen PO daily for 5 years with/without the administration of the somatostatin analogue Octreotide LAR 90 mg depot injection monthly for 2 years. Event-free survival (EFS), the trial’s primary outcome measure, was defined as time from randomization to time of recurrence of primary disease, time of second malignancy or death due to any cause. We investigated the effect of baseline IGF-I, IGFBP-3, and C-peptide levels on EFS. Kaplan-Meier univariate and Cox step-wise multivariate regressions were performed with/without adjustment for the stratification factors of adjuvant chemotherapy, nodal status, and hormone receptor status, and included patient age (years) and tumour size (T-status). Results: These results are based on analysis of patient serum for the trial’s 667 patients. Median follow-up for those alive is 6.1 years; patients experienced 165 events. Higher C-peptide levels were associated with significantly worse EFS in adjusted, and unadjusted, univariate and multivariate analyses. Final efficacy analyses are expected within a few months. Updated analyses for the effects of baseline metabolic markers and body mass index on EFS will be presented. Conclusions: This is the largest data set, and the first clinical trial, linking higher serum C-peptide levels to adverse outcome in patients with early breast cancer. These results raise concern in the context of increasing population prevalence of insulin resistance. Potential novel adjuvant therapies exist as insulin resistance is modifiable.

[Table: see text]

The extended adjuvant NCIC CTG MA.17 trials: Initial and rerandomization studies

Based upon the results of the NCIC CTG MA.17 trial, letrozole has become the only approved aromatase inhibitor (AI) in the extended adjuvant treatment setting following 5 years of tamoxifen therapy. In this trial, the AI letrozole decreased the overall risk of breast cancer recurrence by 42% compared with placebo in postmenopausal women completing 5 years of tamoxifen. The benefit of letrozole exceeded the expected difference after median follow-up of more than 2 years and led to the unblinding of the trial. The 30-month updated analyses found a 4.8%, 4-year disease-free survival improvement overall, an improvement in distant disease-free recurrence in both node-negative and node-positive patients, and a survival benefit for node-positive patients. Generally well tolerated, letrozole caused some adverse events including arthralgias and osteoporosis. However, results from the Zometa-Femara adjuvant synergy trial (Z-FAST) suggest that zoledronic acid, when used concomitantly with letrozole, is able to manage bone loss in postmenopausal women with early breast cancer.

A meta-analysis of two randomised trials of early chemotherapy in asymptomatic metastatic colorectal cancer

This report constitutes a prospectively planned meta-analysis combining two almost identical trials undertaken in Australasia and Canada to study the effect of starting chemotherapy immediately in asymptomatic patients with metastatic colorectal cancer. Patients (n=168) were randomised to receive either immediate or delayed treatment (at onset of predefined symptoms). Australasian patients received either weekly 5-fluorouracil and leucovorin (500 and 20 mg m(-2), respectively) (n=59) or the daily x 5 Mayo Clinic schedule (425 and 20 mg m(-2), respectively) (n=42). Canadian patients were treated with the Mayo schedule (n=67). Otherwise, the two studies were almost identical in design and each used the European Organisation for the Research and Treatment of Cancer (EORTC) QLQ-C30 instrument for measuring quality of life (QoL). Treatment was continued until 6 months had elapsed or disease progression occurred. Low accrual led to trial suspension before the predetermined sample size for either study was reached. Median survival was not significantly better with immediate treatment (median 13.0 vs 11.0 months; hazard ratio, 1.15; 95% confidence interval (CI) 0.79-1.72; P=0.49). There was no statistically significant difference in progression-free survival (time from randomisation until first evidence of progression after chemotherapy, 10.2 vs 10.8 months; hazard ratio, 1.08; 95% CI 0.71-1.64; P=0.73). There was no difference in overall QoL or its individual domains between the two treatment strategies at baseline or at any subsequent time point. Early treatment of asymptomatic patients with metastatic colorectal cancer did not provide a survival benefit or improved QoL compared to withholding treatment until symptoms occurred.

Risk of acute myeloid leukemia and myelodysplastic syndrome in trials of adjuvant epirubicin for early breast cancer: correlation with doses of epirubicin and cyclophosphamide

PURPOSE

We reviewed follow-up of patients treated in 19 randomized trials of adjuvant epirubicin in early breast cancer to determine incidence, risk, and risk factors for subsequent acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

PATIENTS AND METHODS

The patients (N = 9,796) were observed from the start of adjuvant treatment (53,080 patient-years). Cases of AML or MDS (AML/MDS) were reported, with disease characteristics. Incidence and cumulative risk were compared for possible risk factors, for assigned regimens, and for administered cumulative doses of epirubicin and cyclophosphamide.

RESULTS

In 7,110 patients treated with epirubicin-containing regimens (92% of whom also received cyclophosphamide), 8-year cumulative probability of AML/MDS was 0.55% (95% CI, 0.33% to 0.78%). The risk of developing AML/MDS increased in relation to planned epirubicin dose per cycle, planned epirubicin dose-intensity, and administered cumulative doses of epirubicin and cyclophosphamide. Patients with administered cumulative doses of both epirubicin and cyclophosphamide not exceeding those used in standard regimens (</= 720 mg/m(2) and </= 6,300 mg/m(2), respectively) had an 8-year cumulative probability of developing AML/MDS of 0.37% (95% CI, 0.13% to 0.61%) compared with 4.97% (95% CI, 2.06% to 7.87%) for patients administered higher cumulative doses of both epirubicin and cyclophosphamide.

CONCLUSION

Patients treated with standard cumulative doses of adjuvant epirubicin (</= 720 mg/m(2)) and cyclophosphamide (</= 6,300 mg/m(2)) for early breast cancer have a lower probability of secondary leukemia than patients treated with higher cumulative doses. Increased risk of secondary leukemia must be considered when assessing the potential benefit to risk ratio of higher than standard doses.