Genomic characterisation of hormone receptor-positive breast cancer arising in very young women.

BACKGROUND: Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained. PATIENTS AND METHODS: Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS). RESULTS: Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively. CONCLUSION: These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

Impact of baseline BMI and weight change in CCTG adjuvant breast cancer trials.

BACKGROUND: We hypothesized that increased baseline BMI and BMI change would negatively impact clinical outcomes with adjuvant breast cancer systemic therapy. METHODS: Data from chemotherapy trials MA.5 and MA.21; endocrine therapy MA.12, MA.14 and MA.27; and trastuzumab HERA/MA.24 were analyzed. The primary objective was to examine the effect of BMI change on breast cancer-free interval (BCFI) landmarked at 5 years; secondary objectives included BMI changes at 1 and 3 years; BMI changes on disease-specific survival (DSS) and overall survival (OS); and effects of baseline BMI. Stratified analyses included trial therapy and composite trial stratification factors. RESULTS: In pre-/peri-/early post-menopausal chemotherapy trials (N = 2793), baseline BMI did not impact any endpoint and increased BMI from baseline did not significantly affect BCFI (P = 0.85) after 5 years although it was associated with worse BCFI (P = 0.03) and DSS (P = 0.07) after 1 year. BMI increase by 3 and 5 years was associated with better DSS (P = 0.01; 0.01) and OS (P = 0.003; 0.05). In pre-menopausal endocrine therapy trial MA.12 (N = 672), patients with higher baseline BMI had worse BCFI (P = 0.02) after 1 year, worse DSS (P = 0.05; 0.004) after 1 and 5 years and worse OS (P = 0.01) after 5 years. Increased BMI did not impact BCFI (P = 0.90) after 5 years, although it was associated with worse BCFI (P = 0.01) after 1 year. In post-menopausal endocrine therapy trials MA.14 and MA.27 (N = 8236), baseline BMI did not significantly impact outcome for any endpoint. BMI change did not impact BCFI or DSS after 1 or 3 years, although a mean increased BMI of 0.3 was associated with better OS (P = 0.02) after 1 year. With the administration of trastuzumab (N = 1395) baseline BMI and BMI change did not significantly impact outcomes. CONCLUSIONS: Higher baseline BMI and BMI increases negatively affected outcomes only in pre-/peri-/early post-menopausal trial patients. Otherwise, BMI increases similar to those expected in healthy women either did not impact outcome or were associated with better outcomes. CLINICAL TRIALS NUMBERS: CAN-NCIC-MA5; National Cancer Institute (NCI)-V90-0027; MA.12-NCT00002542; MA.14-NCT00002864; MA.21-NCT00014222; HERA, NCT00045032;CAN-NCIC-MA24; MA-27-NCT00066573.

Inhibition of the Aurora A kinase augments the anti-tumor efficacy of oncolytic measles virotherapy.

Oncolytic measles virus (MV) strains have demonstrated broad spectrum preclinical anti-tumor efficacy, including breast cancer. Aurora A kinase controls mitotic spindle formation and has a critical role in malignant transformation. We hypothesized that the Aurora A kinase inhibitor MLN8237 (alisertib) can increase MV oncolytic effect and efficacy by causing mitotic arrest. Alisertib enhanced MV oncolysis in vitro and significantly improved outcome in vivo against breast cancer xenografts. In a disseminated MDA-231-lu-P4 lung metastatic model, the MV/alisertib combination treatment markedly increased median survival to 82.5 days with 20% of the animals being long-term survivors versus 48 days median survival for the control animals. Similarly, in a pleural effusion model of advanced breast cancer, the MV/alisertib combination significantly improved outcome with a 74.5 day median survival versus the single agent groups (57 and 40 days, respectively). Increased viral gene expression and IL-24 upregulation were demonstrated, representing possible mechanisms for the observed increase in anti-tumor effect. Inhibiting Aurora A kinase with alisertib represents a novel approach to enhance MV-mediated oncolysis and antitumor effect. Both oncolytic MV strains and alisertib are currently tested in clinical trials, this study therefore provides the basis for translational applications of this combinatorial strategy in the treatment of patients with advanced breast cancer.

AXL induces epithelial-to-mesenchymal transition and regulates the function of breast cancer stem cells.

Despite significant progress in the treatment of breast cancer, particularly through the use of targeted therapy, relapse and chemoresistance remain a major hindrance to the fight to minimize the burden of the disease. It is becoming increasingly clear that a rare subpopulation of cells known as cancer stem cells (CSC), able to be generated through epithelial-to-mesenchymal transition (EMT) and capable of tumor initiation and self-renewal, contributes to treatment resistance and metastases. This means that a more effective therapy should target both the chemoresistant CSCs and the proliferating epithelial cells that give rise to them to reverse EMT and to attenuate their conversion to CSCs. Here, we demonstrate a novel function of AXL in acting upstream to induce EMT in normal and immortalized human mammary epithelial cells in an apparent positive feedback loop mechanism and regulate breast CSC (BCSC) self-renewal and chemoresistance. Downregulation of AXL using MP470 (Amuvatinib) reversed EMT in mesenchymal normal human mammary epithelial cells and murine BCSCs attenuating self-renewal and restored chemosensitivity of the BCSCs. AXL expression was also found to be associated with the expression of stem cell genes, regulation of metastases genes, increased tumorigenicity and was important for BCSC invasion and migration. Inactivation of AXL also led to the downregulation of nuclear factor-κB pathway and reduced tumor formation in vivo. Taken together, our data suggest that targeted therapy against AXL, in combination with systemic therapies, has the potential to improve response to anticancer therapies and to reduce breast cancer recurrence and metastases.

Impact of premenopausal status at breast cancer diagnosis in women entered on the placebo-controlled NCIC CTG MA17 trial of extended adjuvant letrozole.

BACKGROUND: MA17 showed improved outcomes in postmenopausal women given extended letrozole (LET) after completing 5 years of adjuvant tamoxifen. PATIENTS AND METHODS: Exploratory subgroup analyses of disease-free survival (DFS), distant DFS (DDFS), overall survival (OS), toxic effects and quality of life (QOL) in MA17 were performed based on menopausal status at breast cancer diagnosis. RESULTS: At diagnosis, 877 women were premenopausal and 4289 were postmenopausal. Extended LET was significantly better than placebo (PLAC) in DFS for premenopausal [hazard ratio (HR) = 0.26, 95% confidence interval (CI) 0.13-0.55; P = 0.0003] and postmenopausal women (HR = 0.67; 95% CI 0.51-0.89; P = 0.006), with greater DFS benefit in those premenopausal (interaction P = 0.03). In adjusted post-unblinding analysis, those who switched from PLAC to LET improved DDFS in premenopausal (HR = 0.15; 95% CI 0.03-0.79; P = 0.02) and postmenopausal women (HR = 0.45; 95% CI 0.22-0.94; P = 0.03). CONCLUSIONS: Extended LET after 5 years of tamoxifen was effective in pre- and postmenopausal women at diagnosis, and significantly better in those premenopausal. Women premenopausal at diagnosis should be considered for extended adjuvant therapy with LET if menopausal after completing tamoxifen.

A randomized, placebo-controlled trial (NCIC CTG MAP.2) examining the effects of exemestane on mammographic breast density, bone density, markers of bone metabolism and serum lipid levels in postmenopausal women.

We hypothesized that exemestane (EXE) would reduce mammographic breast density and have unique effects on biomarkers of bone and lipid metabolism. Healthy postmenopausal women were randomized to EXE (25 mg daily) or placebo (PLAC) for 12 months and followed for a total of 24 months. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms and secondary endpoints were changes in serum lipid levels, bone biomarkers, and bone mineral density (BMD). Ninety-eight women were randomized (49 to EXE; 49 to PLAC) and 65 had PD data at baseline and 12 months. Among women treated with EXE, PD was not significantly changed from baseline at 6, 12, or 24 months and was not different from PLAC. EXE was associated with significant percentage increase from baseline in N-telopeptide at 12 months compared with PLAC. No differences in percent change from baseline in BMD (lumbar spine and femoral neck) were observed between EXE and PLAC at either 12 or 24 months. Patients on EXE had a significantly larger percent decrease in total cholesterol than in the PLAC arm at 6 months and in HDL cholesterol at 3, 6, and 12 months. No significant differences in percent change in LDL or triglycerides were noted at any time point between the two treatment arms. EXE administered for 1 year to healthy postmenopausal women did not result in significant changes in mammographic density. A reversible increase in the bone resorption marker N-telopeptide without significant change in bone specific alkaline phosphatase or BMD during the 12 months treatment period and 1 year later was noted. Changes in lipid parameters on this trial were modest and reversible.

Thresholds for therapies: highlights of the St Gallen International Expert Consensus on the primary therapy of early breast cancer 2009.

The 11(th) St Gallen (Switzerland) expert consensus meeting on the primary treatment of early breast cancer in March 2009 maintained an emphasis on targeting adjuvant systemic therapies according to subgroups defined by predictive markers. Any positive level of estrogen receptor (ER) expression is considered sufficient to justify the use of endocrine adjuvant therapy in almost all patients. Overexpression or amplification of HER2 by standard criteria is an indication for anti-HER2 therapy for all but the very lowest risk invasive tumours. The corollary is that ER and HER2 must be reliably and accurately measured. Indications for cytotoxic adjuvant therapy were refined, acknowledging the role of risk factors with the caveat that risk per se is not a target. Proliferation markers, including those identified in multigene array analyses, were recognised as important in this regard. The threshold for indication of each systemic treatment modality thus depends on different criteria which have been separately listed to clarify the therapeutic decision-making algorithm.

Heat shock protein inhibitors increase the efficacy of measles virotherapy.

Oncolytic measles virus strains have activity against multiple tumor types and are currently in phase I clinical testing. Induction of the heat shock protein 70 (HSP70) constitutes one of the earliest changes in cellular gene expression following infection with RNA viruses including measles virus, and HSP70 upregulation induced by heat shock has been shown to result in increased measles virus cytotoxicity. HSP90 inhibitors such as geldanamycin (GA) or 17-allylaminogeldanamycin result in pharmacologic upregulation of HSP70 and they are currently in clinical testing as cancer therapeutics. We therefore investigated the hypothesis that heat shock protein inhibitors could augment the measles virus-induced cytopathic effect. We tested the combination of a measles virus derivative expressing soluble human carcinoembryonic antigen (MV-CEA) and GA in MDA-MB-231 (breast), SKOV3.IP (ovarian) and TE671 (rhabdomyosarcoma) cancer cell lines. Optimal synergy was accomplished when GA treatment was initiated 6-24 h following MV infection. Western immunoblotting confirmed HSP70 upregulation in combination-treated cells. Combination treatment resulted in statistically significant increase in syncytia formation as compared to MV-CEA infection alone. Clonogenic assays demonstrated significant decrease in tumor colony formation in MV-CEA/GA combination-treated cells. In addition there was increase in apoptosis by 4,6-diamidino-2-phenylindole staining. Western immunoblotting for caspase-9, caspase-8, caspase-3 and poly(ADP-ribose) polymerase (PARP) demonstrated increase in cleaved caspase-8 and PARP. The pan-caspase inhibitor Z-VAD-FMK and caspase-8 inhibitor Z-IETD-FMK, but not the caspase-9 inhibitor Z-IEHD-FMK, protected tumor cells from MV-CEA/GA-induced PARP activation, indicating that apoptosis in combination-treated cells occurs mainly via the extrinsic caspase pathway. Treatment of normal cells, such as normal human fibroblasts, however, with the MV-CEA/GA combination, did not result in cytopathic effect, indicating that GA did not alter the MV-CEA specificity for tumor cells. One-step viral growth curves, western immunoblotting for MV-N protein expression, QRT-PCR quantitation of MV-genome copy number and CEA levels showed comparable proliferation of MV-CEA in GA-treated vs -untreated tumor cells. Rho activation assays and western blot for total RhoA, a GTPase associated with the actin cytoskeleton, demonstrated decrease in RhoA activation in combination-treated cells, a change previously shown to be associated with increase in paramyxovirus-induced cell-cell fusion. The enhanced cytopathic effect resulting from measles virus/GA combination supports the translational potential of this approach in the treatment of cancer.

Intent-to-treat analysis of the placebo-controlled trial of letrozole for extended adjuvant therapy in early breast cancer: NCIC CTG MA.17.

BACKGROUND: MA.17 evaluated letrozole or placebo after 5 years of tamoxifen and showed significant improvement in disease-free survival (DFS) for letrozole [hazard ratio (HR) 0.57, P = 0.00008]. The trial was unblinded and placebo patients were offered letrozole. PATIENTS AND METHODS: An intent-to-treat analysis of all outcomes, before and after unblinding, on the basis of the original randomization was carried out. RESULTS: In all, 5187 patients were randomly allocated to the study at baseline and, at unblinding, 1579 (66%) of 2383 placebo patients accepted letrozole. At median follow-up of 64 months (range 16-95), 399 recurrences or contralateral breast cancers (CLBCs) (164 letrozole and 235 placebo) occurred. Four-year DFS was 94.3% (letrozole) and 91.4% (placebo) [HR 0.68, 95% confidence interval (CI) 0.55-0.83, P = 0.0001] and showed superiority for letrozole in both node-positive and -negative patients. Corresponding 4-year distant DFS was 96.3% and 94.9% (HR 0.80, 95% CI 0.62-1.03, P = 0.082). Four-year overall survival was 95.1% for both groups. The annual rate of CLBC was 0.28% for letrozole and 0.46% for placebo patients (HR 0.61, 95% CI 0.39-0.97, P = 0.033). CONCLUSIONS: Patients originally randomly assigned to receive letrozole within 3 months of stopping tamoxifen did better than placebo patients in DFS and CLBC, despite 66% of placebo patients taking letrozole after unblinding.

Estrogen-TGFbeta cross-talk in bone and other cell types: role of TIEG, Runx2, and other transcription factors.

It is well established that E(2) and TGFbeta have major biological effects in multiple tissues, including bone. The signaling pathways through which these two factors elicit their effects are well documented. However, the interaction between these two pathways and the potential consequences of cross-talk between E(2) and TGFbeta continue to be elucidated. In this prospectus, we present known and potential roles of TIEG, Runx2, and other transcription factors as important mediators of signaling between these two pathways.

Pilot study of the impact of letrozole vs. placebo on breast density in women completing 5 years of tamoxifen.

Breast density, a strong risk factor for breast cancer, is reduced by the anti-estrogen, tamoxifen (TAM). We examined whether aromatase inhibitor (AI) therapy results in further reductions in breast density among women completing 5 years of TAM. Among a sample of women with early-onset breast cancer who were randomized to letrozole (LET)(n=56) or placebo (PLAC)(n=48) after 5 years of TAM, we examine the change in percent density at 9-15 months as well as a per-year change in PD by treatment group. There was no difference in the adjusted mean change (-1.0%, LET; -0.3%, PLAC (P=0.58)) or the percentage change (-2.7%, LET; -3.0%, PLAC (P=0.96)) in PD between treatment groups at 9-15 months. Results were similar for longitudinal change (-0.68% per year, LET; -0.12% per year, PLAC (P=0.23)). Breast density does not appear to be a clinically relevant biomarker in women who already have low PD following 5 years of TAM.

Clinical outcomes of ethnic minority women in MA.17: a trial of letrozole after 5 years of tamoxifen in postmenopausal women with early stage breast cancer.

BACKGROUND: Aromatase inhibitors are widely employed in the adjuvant treatment of early stage breast cancer. The impact of aromatase inhibitors has not been established in ethnic minority women. PATIENTS AND METHODS: The purpose of this study was to evaluate the impact of letrozole on minority women in MA.17, a placebo-controlled trial of letrozole following 5 years of tamoxifen in postmenopausal women with early stage breast cancer. Retrospective comparison of disease-free survival (DFS), side effects, and mean changes in quality of life (QOL) scores from baseline between Caucasian and minority women was performed. RESULTS: Minority (n = 352) and Caucasian (n = 4708) women were analyzed. There was no difference between these groups in DFS (91.6% versus 92.4% respectively for 4 year DFS). Letrozole, compared with placebo, significantly improved DFS for Caucasians (HR = 0.55; P < 0.0001) but not for minorities (HR = 1.39; P = 0.53). Among women who received letrozole, minorities had a significantly lower incidence of hot flashes (49% versus 58%; P = 0.02), fatigue (29% versus 39%; P = 0.005), and arthritis (2% versus 7%; P = 0.006) compared with Caucasians. Mean change in QOL scores for minority women who received letrozole demonstrated improved mental health at the 6-month assessment (P = 0.02) and less bodily pain at the 12-month assessment (P = 0.046). CONCLUSION: Letrozole improved DFS in Caucasians but a definite benefit in minority women has not yet been demonstrated. Minority women tolerated letrozole better than Caucasians in terms of toxicity. These results need confirmation in other trials of aromatase inhibitors.

A phase II trial of a combination of pemetrexed and gemcitabine in patients with metastatic breast cancer: an NCCTG study.

PURPOSE: This phase II study was undertaken to define the efficacy and toxicity of pemetrexed in combination with gemcitabine in patients with metastatic breast cancer. PATIENTS AND METHODS: Patients with measurable metastatic breast cancer who had previously received an anthracycline and a taxane in either the adjuvant or metastatic setting were treated with gemcitabine 1250 mg/m2 (intravenous; days 1 and 8) and pemetrexed 500 mg/m2 (intravenous; day 8) every 21 days. RESULTS: Fifty-nine patients received a median of five cycles (range one to 22) of treatment and were followed until death or for a median of 28 months (range 19.4-36.6) among living patients. Fourteen partial responses for an overall response rate of 24% [95% confidence interval (CI) 16% to 39%] were documented. Nine (15%; CI 5% to 32%) patients had stable disease for >6 months. The median survival time was 10.3 months (95% CI 8.3-18.9) and the 1 year survival rate was 49% (95% CI 38% to 64%). The median time to progression was estimated to be 3.7 months (95% CI 2.3-5.3). The most common grade 3 or 4 toxicities were neutropenia and thrombocytopenia in 83% and 27% of patients, respectively. Fourteen percent of patients experienced febrile neutropenia. Other common grade 3 or 4 non-hematological toxicities included fatigue (17%), dyspnea (15%), rash (7%) and anorexia (5%). CONCLUSIONS: The combination of pemetrexed and gemcitabine is clinically active, with an overall response rate of 24% in patients with metastatic breast cancer who have previously been treated with an anthracycline and a taxane. Myelosuppression (66% grade 4 neutropenia and 14% febrile neutropenia) was the major treatment-related toxicity observed for this combination.

The influence of letrozole on serum lipid concentrations in postmenopausal women with primary breast cancer who have completed 5 years of adjuvant tamoxifen (NCIC CTG MA.17L).

BACKGROUND: The purpose of this study was to evaluate changes in serum lipid parameters {cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and lipoprotein(a) [Lp(a)]}, in postmenopausal women receiving letrozole or placebo after adjuvant tamoxifen for early stage breast cancer (NCIC CTG MA.17L). PATIENTS AND METHODS: MA.17L is a substudy of MA.17, a randomized, double-blind, placebo-controlled trial of letrozole 2.5 mg taken daily for 5 years in postmenopausal women with primary breast cancer completing approximately 5 years of prior adjuvant tamoxifen. Patients consenting to participate in this companion study had blood drawn and lipid parameters (total cholesterol, HDL cholesterol, LDL cholesterol, Lp(a), triglycerides) evaluated at baseline, 6 months, 12 months and yearly thereafter until completion of protocol therapy. It was required that women be non-hyperlipidemic and not taking lipid-lowering drugs at time of entry on this trial. RESULTS: Three hundred and forty seven women were enrolled in the study. The letrozole and the placebo groups demonstrated marginally significant differences in the percentage change from baseline in HDL cholesterol at 6 months (P=0.049), in LDL cholesterol at 12 months (P=0.033) and triglycerides at 24 months (P=0.036). All comparisons of lipid parameters at other time points were not significantly different between the two treatment groups. No statistically significant differences in the number of patients exceeding the thresholds defined for the lipid parameters were found between the two treatment groups. CONCLUSIONS: The MA.17 trial demonstrated a significant improvement in disease-free survival with the use of letrozole as extended adjuvant therapy post tamoxifen. Results from this study suggests that letrozole does not significantly alter serum cholesterol, HDL cholesterol, LDL cholesterol, triglycerides or Lp(a) in non-hyperlidiemic postmenopausal women with primary breast cancer treated up to 36 months following at least 5 years of adjuvant tamoxifen therapy. These findings further support the tolerability of extended adjuvant letrozole in postmenopausal women following standard tamoxifen therapy.

Primary breast sarcoma: clinicopathologic series from the Mayo Clinic and review of the literature.

Primary sarcomas of the breast are extremely rare, with less than 0.1% of all malignant tumours of the breast. Mayo Clinic Surgical Pathology database was searched for all breast sarcoma from 1910 to 2000. Pathology reports and slides were reviewed and tumour types were determined. Metaplastic carcinomas and phyllodes tumours were excluded. There were 25 women ranging in age 24-81 years (mean 45 years). All but one patient presented with a palpable lump. Mastectomy was performed in 19 patients and lumpectomy in five patients. Histopathological diagnoses were fibrosarcoma (six), angiosarcoma (six), pleomorphic sarcoma (six), leiomyosarcoma (two), myxofibrosarcoma (three), hemangiopericytoma (one) and osteosarcoma (one). Tumour size ranged from 0.3 to 12 cm (mean 5.7). Low-grade lesions were observed in 10 cases and high-grade in 15. Overall, mean follow-up was 10.5 years. Local recurrence was observed in 11 patients and ranged from 2 to 36 months (mean 15 m), while distant metastasis was observed in 10 patients (40%) affecting lungs, bones, liver, spleen, and skin. Of the 25 patients, 12 have died of disease and six of other causes. Five-year overall (OS) and cause-specific survival (CSS) were 66 and 70%, respectively. OS and DFS at 5 years were 91% for tumours < or =5 cm and 50% for tumours >5 cm. Tumour size was significantly associated with OS (risk ratio=1.3 per 1 cm increase; 95% CI, 1.02-1.7; P=0.036). There was no significant difference in OS or CSS between low- and high-grade lesions. In this series, tumour size was a more valuable prognostic factor than tumour grade.

A randomized phase II study of sequential docetaxel and doxorubicin/cyclophosphamide in patients with metastatic breast cancer.

BACKGROUND: Docetaxel has yielded promising response rates as a component of doxorubicin-based combination schedules in patients with metastatic breast cancer, including docetaxel/doxorubicin and docetaxel/doxorubicin/cyclophosphamide (AC). This randomized two-stage phase II study was conducted to evaluate sequential treatment with docetaxel and AC as first-line treatment in patients with recurrent or metastatic breast cancer previously untreated with chemotherapy for metastatic disease. PATIENTS AND METHODS: Thirty-three patients were randomized to either docetaxel (100 mg/m(2)) on day 1 of a 21-day cycle for three cycles followed by AC (60/600 mg/m(2)) on day 1 of a 21-day cycle for three cycles (n = 17) or vice-versa (n = 16), without prophylactic granulocyte colony-stimulating factor support. In addition, we compared pre-treatment serum sErbB1 and sErbB2 protein concentrations with that of an age- and menopausal status-matched group of healthy women, and examined changes in serum sErbB1 and sErbB2 protein concentrations in these two treatment schedules. Data from each one of the two arms of the trial (docetaxel then AC, or AC and then docetaxel) were analyzed separately. RESULTS: Enrollment was suspended after the first-stage of accrual, based on statistical design. Confirmed objective response rates after six cycles of treatment were 35% [95% confidence interval (CI) 14% to 62%] with docetaxel then AC and 38% (95% CI 15% to 65%) with AC then docetaxel. Dose reductions were frequent and mostly due to grade 4 neutropenia. Median survival time was 2.5 years in the docetaxel then AC group, and 1.1 years in the AC then docetaxel group. Serum sErbB1 concentrations were not significantly different between the study patients and healthy women, and did not change significantly after three and six cycles of treatment. In contrast, serum sErbB2 concentrations were significantly higher in the study patients compared with healthy women and tended to decrease after three and six cycles of treatment. CONCLUSIONS: Response rates at the end of six cycles of treatment, which led to termination of accrual after the first stage using either the sequence of docetaxel first or docetaxel after AC chemotherapy, were lower than anticipated. However, median survival times and median progression-free survival times are similar to those reported in other studies. These data further suggest that additional studies to assess whether serum sErbB2 concentrations are useful predictors of responsiveness to chemotherapy are warranted.

Aromatase inhibition and antiestrogen therapy in early breast cancer treatment and chemoprevention.

The aromatase inhibitors represent an important class of hormonal agents for the management of breast cancer. The third-generation aromatase inhibitors have replaced megestrol acetate as second-line hormonal therapy in advanced breast cancer, and large clinical trials are maturing to establish their efficacy relative to tamoxifen (Nolvadex) in the first-line metastatic setting. The increased potency, increased specificity, and established efficacy of aromatase inhibitors in advanced breast cancer have provided the rationale for a large number of randomized trials in the adjuvant setting evaluating anastrozole (Arimidex), exemestane (Aromasin), and letrozole (Femara). These trials are addressing the value of these agents in sequence with, instead of, and in combination with tamoxifen. The relationship between estrogen exposure and breast cancer risk has long been accepted and traditionally related to estrogen-receptor-mediated events. The emergence of the estrogen genotoxicity hypothesis as a mechanism for breast cancer carcinogenesis provides additional rationale for considering aromatase inhibitors in the chemoprevention setting.

Structural analysis of the 17q22-23 amplicon identifies several independent targets of amplification in breast cancer cell lines and tumors.

A novel region of amplification in breast tumors has recently been identified on chromosome 17q22-23. In an effort to identify the oncogenes in the region that are targeted by the amplification process, we determined the structure of the amplicon in breast cancer cell lines and tumors. Physical and transcription maps of the approximately 3.5-Mb region were established and used as the basis for copy number analysis within the region by Southern blot and fluorescence in situ hybridization. Seven specific and independent amplification maxima were identified in breast cancer cell lines and breast tumors. We present correlative amplification and overexpression studies for the FLJ21316 and Hs.6649 genes suggesting a role for these candidates as amplification-dependent oncogenes.