Pharmacokinetics and tolerability of exemestane in combination with raloxifene in postmenopausal women with a history of breast cancer

PURPOSE

Raloxifene is a second-generation selective estrogen receptor modulator that reduces the incidence of breast cancer in postmenopausal women. Exemestane, a steroidal aromatase inhibitor, decreases contralateral new breast cancers in postmenopausal women when taken in the adjuvant setting. Preclinical evidence suggests a rationale for coadministration of these agents to achieve complete estrogen blockade.

EXPERIMENTAL DESIGN

We tested the safety and tolerability of combination exemestane and raloxifene in 11 postmenopausal women with a history of hormone receptor-negative breast cancer. Patients were randomized to either raloxifene (60 mg PO daily) or exemestane (25 mg PO daily) for 2 weeks. Patients then initiated combination therapy at the same dose levels for a minimum of 1 year. Pharmacokinetic and pharmacodynamic data for plasma estrogens, raloxifene, exemestane, and their metabolites were collected at the end of single-agent therapy and during combination therapy.

RESULTS

Plasma concentration-time profiles for each drug were unchanged with monotherapy versus combination therapy. Raloxifene did not affect plasma estrogen levels. Plasma estrogen concentrations were suppressed below the lower limit of detection by exemestane as monotherapy and when administered in combination with raloxifene. The most common adverse events of any grade included arthralgias, hot flashes, vaginal dryness and myalgias.

CONCLUSIONS

In this small study, coadministration of raloxifene and exemestane did not affect the pharmacokinetics or pharmacodynamics of either agent to a significant degree in postmenopausal women. The combination of estrogen receptor blockade and suppression of estrogen synthesis is well tolerated and warrants further investigation.

Hyperinsulinaemia during exercise does not suppress hepatic glycogen concentrations in patients with type 1 diabetes: a magnetic resonance spectroscopy study

AIMS/HYPOTHESIS

We compared in vivo changes in liver glycogen concentration during exercise between patients with type 1 diabetes and healthy volunteers.

METHODS

We studied seven men with type 1 diabetes (mean +/- SEM diabetes duration 10 +/- 2 years, age 33 +/- 3 years, BMI 24 +/- 1 kg/m(2), HbA(1c) 8.1 +/- 0.2% and VO(2) peak 43 +/- 2 ml [kg lean body mass](-1) min(-1)) and five non-diabetic controls (mean +/- SEM age 30 +/- 3 years, BMI 22 +/- 1 kg/m(2), HbA(1c) 5.4 +/- 0.1% and VO(2) peak 52 +/- 4 ml [kg lean body mass](-1) min(-1), before and after a standardised breakfast and after three bouts (EX1, EX2, EX3) of 40 min of cycling at 60% VO(2) peak. (13)C Magnetic resonance spectroscopy of liver glycogen was acquired in a 3.0 T magnet using a surface coil. Whole-body substrate oxidation was determined using indirect calorimetry.

RESULTS

Blood glucose and serum insulin concentrations were significantly higher (p < 0.05) in the fasting state, during the postprandial period and during EX1 and EX2 in subjects with type 1 diabetes compared with controls. Serum insulin concentration was still different between groups during EX3 (p < 0.05), but blood glucose concentration was similar. There was no difference between groups in liver glycogen concentration before or after the three bouts of exercise, despite the relative hyperinsulinaemia in type 1 diabetes. There were also no differences in substrate oxidation rates between groups.

CONCLUSIONS/INTERPRETATION

In patients with type 1 diabetes, hyperinsulinaemic and hyperglycaemic conditions during moderate exercise did not suppress hepatic glycogen concentrations. These findings do not support the hypothesis that exercise-induced hypoglycaemia in patients with type 1 diabetes is due to suppression of hepatic glycogen mobilisation.

Skeletal muscle fatty acid transporter protein expression in type 2 diabetes patients compared with overweight, sedentary men and age-matched, endurance-trained cyclists

AIM

Membrane fatty acid transporters can modulate the balance between fatty acid uptake and subsequent storage and/or oxidation in muscle tissue. As such, skeletal muscle fatty acid transporter protein expression could play an important role in the etiology of insulin resistance and/or type 2 diabetes.

METHODS

In the present study, fatty acid translocase (FAT/CD36), plasma membrane-bound fatty acid-binding protein (FABPpm) and fatty acid transport protein 1 (FATP1) mRNA and protein expression were assessed in muscle tissue obtained from 10 sedentary, overweight type 2 diabetes patients (60 +/- 2 years), 10 sedentary, weight-matched normoglycemic controls (60 +/- 2 years) and 10 age-matched, endurance trained cyclists (57 +/- 1 years).

RESULTS

Both FAT/CD36 and FATP1 mRNA and protein expression did not differ between groups. In contrast, FABPpm mRNA and protein expression were approx. 30-40% higher in the trained men compared with the diabetes patients (P < 0.01) and sedentary controls (P < 0.05).

CONCLUSIONS

Skeletal muscle FAT/CD36, FABPpm and FATP1 mRNA and protein expression are not up- or downregulated in a sedentary and/or insulin resistant state. In contrast, FABPpm expression is upregulated in the endurance trained state and likely instrumental to allow greater fatty acid oxidation rates.

Adjuvant (adj) bevacizumab (B) plus dose-dense (dd) doxorubicin/cyclophosphamide (AC) followed by nanoparticle albumin- bound paclitaxel (nab-p) in early stage breast cancer (BC) patients (pts): Cardiac safety

567

Background: Dose dense, q2 wk AC-paclitaxel (T) is superior to q3 wk therapy (Rx) (Citron, JCO 2003). The risk of congestive heart failure (CHF) with ddAC-T is not increased at <1%. In MBC, B improves PFS when added to T (Miller, SABCS 2005). It is unclear if doxorubicin plus B increases risk of CHF. Hence, we are testing the cardiac safety of ddAC-nab-p with concurrent B as adj therapy. Based upon the accepted cardiac event (CE) rate of ≤4% in trials with adj trastuzumab (an agent with known cardiac toxicity), we designed this study with similar monitoring & tolerability thresholds. The primary endpoint is cardiac safety, defined as discontinuation of B due to cardiac death from LV dysfunction or symptomatic CHF (dyspnea and LVEF<50%). Secondary endpoints: toxicity, disease-free & overall survival. Methods: Eligible pts have resected HER2(-) BC and normal LVEF. Rx consists of q2wk AC (60/600 mg/m2) ×4 then nab-p (260 mg/m2) x4 with pegfilgrastim on Day 2 plus B for one year (10mg/kg IV q2wk ×8 with chemoRx then B 15mg/kg q3wk); radiation & endocrine Rx per standard of care. MUGA obtained at baseline & mos. 2, 6, 9, 18. Pts with significant asymptomatic ↓LVEF during Rx may have B held per protocol. These pts are not counted as CEs but will have long-term cardiac monitoring. Accrual goal is 75 pts. If ≥3 CE (∼4.7%) or >1 cardiac death from LV dysfunction, B + ddAC-nab-p will not be considered safe. Results: 44 pts have enrolled, median (med) age 46.5 yrs (33–67). 28 pts have baseline & month 2 LVEF data: med baseline LVEF 68% (61–82), med LVEF at mo. 2 after ddAC+B 68% (53–75); 1 pt had an 18 point asymptomatic drop to 53% - B held but reinitiated in 4 wks with repeat LVEF 63%. 12 pts completed nab-p+B but none have reached the 6 mo. MUGA. Rx-related Gr 3/4 toxicity: neutropenia gr4 (6.8%), diarrhea gr3 (2.3%), hypertension gr3 (2.3%), neuropathy gr 3 (2.3%), fatigue gr 3 (2.3%), mucositis gr 3 (2.3%). 4 pts have withdrawn from study Rx, but only 1 due to toxicity including gr3 fatigue, mucositis & neuropathy. Conclusions: No LV dysfunction has been observed with B + ddAC-nab-p; this trial is on-going. Long-term follow-up and analysis of troponin, renin and circulating endothelial & tumor cells are planned.

No significant financial relationships to disclose.

Extracellular cleaved HER2 (p95) confers partial resistance to trastuzumab but not HSP90 inhibitors in models of HER2 amplified breast cancer

10515

Background: Breast cancers containing an amplified copy of the HER2 receptor tyrosine kinase represent 20–30% of all cases and antibody directed therapy targeting the extracellular domain of HER2 with trastuzumab has proven broadly efficacious. However, resistance to trastuzumab is a common phenomenon. Recent work has identified a cleaved, 95kD version of HER2 that lacks the extracellular epitope in which the trastuzumab binding site is found. Presence of this so called “p95” has been correlated with a worse clinical prognosis. We hypothesized that p95 may enable tumor resistance to trastuzumab. Methods/Results: We established models of p95 expressing breast cancer by transfecting p95 into preexisting models of HER2 amplified breast cancer. We find that cells expressing p95 display increased resistance to the growth inhibitory effects of trastuzumab. The PI3K-AKT pathway that is downregulated by Trastuzumab is less affected in the p95 expressing cells. Furthermore, p95 demonstrates an association with HER3 that is unaffected by trastuzumab treatment. Next, we evaluated the efficacy of therapies targeted against the intracellular domain of HER2 such as the HSP90 inhibitor, 17-AAG. HER2 requires HSP90 for its conformational stability and inhibitors of HSP90 result in growth inhibition of HER2+ breast cancer. We find that p95 displays a similar requirement for HSP90 as inhibitors of HSP90 result in the degradation of p95. Moreover, cells overexpressing p95 are equally susceptible to the antitumor effects of HSP90 inhibitors as those without high levels of p95. Finally, we utilized an empirically derived, in vivo model of trastuzumab resistance that displays high level expression of p95. As with the transfected models, these tumors retain their sensitivity to HSP90 inhibitors as treatment of mice bearing tumors results in both degradation of HER2 and p95 as well as robust tumor growth inhibition. Conclusions: Given the presence of p95 in human breast tumor samples, the data suggest that p95 may play an important role in mediating clinical resistance to trastuzumab. They further suggest that such tumors may retain their sensitivity to targeted therapy against the intracellular portion of HER2 such as with lapatinib or 17-AAG.

No significant financial relationships to disclose.

Phase I study of a novel capecitabine schedule based on Norton-Simon mathematical modeling

1045

Background: We have previously described a mathematical method to optimize chemotherapy dose and schedule (Norton et al, AACR 2005). Capecitabine (C) has activity in breast cancer when conventionally dosed for 14 days (d) q3 weeks (14/7). However, the predicted optimal dosing schedule for C using our model is 7d followed by a 7d rest (biweekly, 7/7). We tested this hypothesis in a Phase I/II study described below. Methods: Eligible patients (pts) have measurable, metastatic breast cancer (MBC), ECOG performance status (PS) =2 and normal organ function. There is no limit to number of prior chemotherapy (CRx) regimens. Pts with prior fluoropyrimidine for MBC are excluded. HER2+ pts must not be candidates for trastuzumab. C is given in divided daily doses for 7d followed by a 7d rest. A standard “3+3” dose escalation scheme employs flat dosing which begins at 1,500mg BID and increases by 500mg/dose level. Primary endpoint is the maximum tolerated dose (MTD), defined as the highest dose for which the incidence of dose-limiting toxicity (DLT) is <33%. Results: 19 pts are now accrued; 17 pts have been treated, 2 withdrew prior to receiving C. Medians: age 47 y (range 34–62 y) and ECOG PS 0 (range 0–2). Sites of MBC: bone 8, viscera 16, soft tissue 11. ER/PR+ 11. HER2+ or unknown 2. Prior adjuvant tx: CRx 17, hormone tx 10. Six pts had adjuvant fluoropyrimidine-based tx. Three pts had 1 prior CRx for MBC; 12 pts received first-line hormone tx for MBC. Fifteen pts had prior anthracycline and taxane. Treatment-related toxicities after a median of 4 cycles (range 1–10) are shown in the table . The MTD has not been reached. Pts continue accrual to the 2500mg/2500mg dose level. Conclusions: Capecitabine 7/7 is well tolerated and allows for safe delivery of higher daily doses than routinely used in practice, as predicted by the mathematical model. Capecitabine 7/7 will be tested in a Phase II program at MSKCC in combination with targeted agents.

[Table: see text]

No significant financial relationships to disclose.

Preclinical testing of a novel regimen of capecitabine (C) in combination with bevacizumab (B) and trastuzumab (T) in a breast cancer xenograft model

1049

Background: Mathematical methods applied to xenograft breast cancer models have determined that the maximum impact of C therapy occurs after ∼7 days (7d) of treatment (Norton AACR 2005). The model predicts that doses of C beyond 7d will contribute to toxicity without additional antitumor benefit. The tolerability and anti-tumor activity of C 7d on/7d off (7/7) in female nude mice bearing KPL-4 breast cancer xenografts has been established (SABCS 2006). We now report preclinical models of C7/7 with targeted therapies. Methods: We evaluated the tumor growth inhibition (TGI%) and increase in life span (ILS%) of C7/7 and B with or without T in female nude mice bearing KPL-4, HER2+ breast cancer xenografts. C at maximum tolerated dose (MTD) and ½MTD were tested in combination with conventional doses of the antibodies. Results: C7/7 at MTD is well tolerated in combination with conventional dose B + T. No toxicity was observed at any dose level. The addition of B ± T to C7/7 monotherapy significantly improves TGI%. Survival is significantly prolonged for the combination of C7/7 MTD with B ± T. Comparative results for C7/7 at MTD and ½ MTD are shown in the Table . Additional comparative data will be shown at the meeting. Assessment of ILS% is ongoing for the triplet C7/7 + B + T but has exceeded 463% and >152 days. Conclusions: The improvement in response and survival shown here supports the study of combination C7/7 with B and T. Combinations with B and anti-HER2 therapy will be tested in the clinical, Phase II program at MSKCC.

[Table: see text]

[Table: see text]

Characterization of GLUT4 and calpain expression in healthy human skeletal muscle during fasting and refeeding

AIMS

Calpain-10 and calpain-3 and the diabetes ankyrin repeat protein (DARP) have all been linked to insulin resistance and type 2 diabetes. We set out to measure the expression of these genes in human skeletal muscle and relate them to functional measurements of insulin action during fasting (which induces insulin resistance) and refeeding (which reverses it).

METHODS

Ten healthy male volunteers underwent 48 h of starvation followed by 24 h of high carbohydrate refeeding. On three occasions, before and after starvation and after refeeding, subjects underwent a 16 min insulin tolerance test to quantify insulin sensitivity. Muscle biopsies were obtained before and after fasting and after refeeding for the analysis of calpain-10 and calpain-3, GLUT4 and DARP expression by Western blotting and real-time PCR.

RESULTS

Fasting led to a marked reduction in whole body insulin sensitivity by approx. 45% (P<0.01) and skeletal muscle GLUT4 gene expression by approx. 40% (P<0.05). However, fasting had no effect on calpain-10 and calpain-3 mRNA or protein levels, or DARP mRNA expression. Refeeding only partly restored insulin sensitivity and GLUT4 gene expression to their pre-fast values, but did not effect the expression of calpain-10, calpain-3 or DARP.

CONCLUSIONS

These findings demonstrate that in healthy non-diabetic humans induction of insulin resistance by fasting and its reversal by refeeding with a high CHO diet is mirrored by changes in skeletal muscle GLUT4 but not calpain-10 and calpain-3 expression.

Exercise under hyperinsulinaemic conditions increases whole-body glucose disposal without affecting muscle glycogen utilisation in type 1 diabetes

AIMS/HYPOTHESIS

We examined whole-body and muscle metabolism in patients with type 1 diabetes during moderate exercise at differing circulating insulin concentrations.

METHODS

Eight men (mean +/- SEM age 36.4 +/- 1.5 years; diabetes duration 11.3 +/- 1.4 years; BMI 24.6 +/- 0.7 kg/m(2); HbA(1c) 7.9 +/- 0.2% and VO(2) peak 44.5 +/- 1.2 ml kg(-1) min(-1)) with type 1 diabetes were studied on two occasions at rest (2 h) and during 45 min of cycling at 60% maximum VO(2) with insulin infused at the rate of either 15 (LO study) or 50 (HI) mU m(-2) min(-1) and blood glucose clamped at 8 mmol/l. Indirect calorimetry, insulin-glucose clamps and thigh muscle biopsies were employed to measure whole-body energy and muscle metabolism.

RESULTS

Fat oxidation contributed 15 and 23% to total energy expenditure during exercise in the HI and LO studies, respectively. The respective carbohydrate (CHO) oxidation rates were 31.7 +/- 2.7 and 27.8 +/- 1.9 mg kg(-1) min(-1) (p < 0.05). Exogenous glucose utilisation rate during exercise was substantially greater (p < 0.001) in the HI study (18.4 +/- 2.1 mg kg(-1) min(-1)) than in the LO study (6.9 +/- 1.2 mg kg(-1) min(-1)). Muscle glycogen content fell by approximately 40% during exercise in both trials. Muscle glycogen utilisation, muscle intermediary metabolism, and phosphorylation of protein kinase B/Akt, glycogen synthase kinase 3alpha/beta and extracellular signal-regulated protein kinase 1 and 2 proteins were no different between interventions.

CONCLUSIONS/INTERPRETATION

In patients with type 1 diabetes, exercise under peak therapeutic insulin concentrations increases exogenous glucose utilisation but does not spare muscle glycogen utilisation. A disproportionate increase in exogenous glucose utilisation relative to the increase in CHO oxidation suggests an increase in glucose flux through non-oxidative pathways.

High-fat/low-carbohydrate diet reduces insulin-stimulated carbohydrate oxidation but stimulates nonoxidative glucose disposal in humans: An important role for skeletal muscle pyruvate dehydrogenase kinase 4

AIM

The aim of this report was to study the effect of high-fat (HF)/low-carbohydrate (CHO) diet on regulation of substrate metabolism in humans.

METHODS

Ten healthy men consumed either a HF (75% energy as fat) or control (35%) diet for 6 d in random order. On d 7, blood glucose disappearance rate (Rd) was determined before and during a hyperinsulinemic euglycemic clamp. Substrate oxidation was determined by indirect calorimetry. Muscle biopsies were obtained prediet, postdiet, and postclamps.

RESULTS

Rd was similar under basal conditions but slightly elevated (approximately 10%, P < 0.05) during the last 30 min of the clamp after the HF diet. HF diet reduced CHO oxidation under basal (by approximately 40%, P < 0.05) and clamp conditions (by approximately 20%, P < 0.05), increased insulin-mediated whole-body nonoxidative glucose disposal (by 30%, P < 0.05) and muscle glycogen storage (by approximately 25%, P < 0.05). Muscle pyruvate dehydrogenase complex activity was blunted under basal and clamp conditions after HF compared with control (P < 0.05) and was accompanied by an approximately 2-fold increase (P < 0.05) in pyruvate dehydrogenase kinase 4 (PDK4) mRNA and protein expression.

CONCLUSION

Short-term HF/low-CHO dietary intake did not induce whole-body insulin resistance, but caused a shift in im glucose metabolism from oxidation to glycogen storage. Insulin-stimulated CHO oxidation and muscle pyruvate dehydrogenase complex activity were blunted after the HF diet. Up-regulation of muscle PDK4 expression was an early molecular adaptation to these changes, and we showed for the first time in healthy humans, unlike insulin-resistant individuals, that insulin can suppress PDK4 but not PDK2 gene expression in skeletal muscle.

Updated cardiac safety results of dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by paclitaxel (T) with trastuzumab (H) in HER2/neu overexpressed/amplified breast cancer (BCA)

582

Background: DD q 2 weekly (w) AC → T is superior to conventionally scheduled (cs) AC → T and safe w/long follow-up (Hudis et al, SABCS 2005). With q 3 wk AC, adjuvant (adj) H is safe and effective (Romond et al and Perez et al, NEJM 2005). We therefore tested DD q 2 w AC → T + H × 1 year (y) as adj treatment (Rx) of patients (pts) with HER2/neu (+) BCA to determine cardiac safety. Based on the reported cardiac event (CE) rate of ≤ 4% in the randomized trials using cs chemotherapy (CRx) + H, we evaluated DD q 2 w AC → T + H with a 1° endpoint of cardiac safety defined as discontinuation (DC) of H due to 1) cardiac death or 2) congestive heart failure (CHF). The 2° endpoint is time to recurrence and overall survival. Methods: Pts with HER2/Neu IHC 3+ or FISH-amplified BCA were enrolled, regardless of tumor size or nodal status. Rx consisted of AC at 60/600 mg/m2 × 4 → T at 175 mg/m2 × 4 q 2 w w/pegfilgrastim 6 mg on d 2 + H × 1 y. Multi-gated radionuclide angiography scan (MUGA) is obtained at baseline and at months (mo) 2 (after AC × 4), 6 (after T × 4), 9, and 18. Pts w/baseline LVEF of ≥ 55% and w/o cardiac illnesses are eligible. Pts w/significant (sig) asymptomatic (asx) LVEF ↓ after DD AC based on mo 2 MUGA did not receive H, and pts w/sig asx LVEF ↓ during H had it DC’d. If the CE rate is > 4%, Rx is deemed not feasible. Results: From January 4, 2005 to November 1, 2005, 70 pts were enrolled. Median (med) age is 49 years (range, 27–72). Forty one of 70 pts (60%) had node (+) BC and 27/70 pts (40%) had (-) nodes. Med baseline LVEF is 68% (range, 55%-81%). As of January 9, 2005, all pts had mo 2 MUGA after DD AC and there is no sig LVEF ↓ and the med LVEF is 67% (range, 58%-79%). To date 39 pts had mo 6 MUGA w/med LVEF of 66% (range, 56%-75%) and one pt had a sig asx LVEF ↓ from baseline of 74% to 56%; H was DC’d. Twenty-three pts had mo 9 MUGA w/a med LVEF of 64% (range, 57%-69%). One patient had clinical CHF at mo 4 w/EF of 45% and improved sig w/cardiac medications. One had pneumonitis during radiation (RT). One had atrial fibrillation w/pericarditis after completion of RT. Discussion: DD AC → T + H appears to have an acceptable cardiac toxicity profile w/1/70 pts having a CE. Updated cardiac safety data will be presented.

[Table: see text]

Toxicity of older and younger patients (pts) treated (Rx) with intensive adjuvant chemotherapy (Cx) for node-positive (N+) breast cancer (BC): The CALGB experience

559

Background: Recent data show older pts derive the same relapse-free and survival benefits as younger pts when treated with newer more intense adjuvant ADJ Cx regimens (Jama 293:1073, 2005). We now compare toxicity of older and younger pts treated in 3 CALGB ADJ trials that used recently developed, intensive Cx regimens including anthracyclines and paclitaxel (T). Methods: Toxicity data were available for 6174 of 6642 pts (93%) enrolled in 3 CALGB/CTSU randomized clinical trials for N+ BC [8541: comparison of CAF in 3 dose schedules; 9344: AC ± T; 9741: ATC dose-dense vs q3 weeks]. Grade (G) 3–5 (NCI criteria) toxicities were compared by age at enrollment (<50, 51–64, 65+). Results: 7% (458) pts were 65+, 3% were 70+, 38% were 51–64 and 55% were <50 years. Incidence of major toxicities and Cx-attributed causes of death are tabulated below. Discontinuation of Cx for toxicity was reported in 6% of 65+, 4% of 51–64 and 3% of <50 pts. 22 of 6642 pts (0.33%) died of causes attributed to Cx; 7/486 (1.4%) of 65+, 8/2480 (0.32%) of 51–64 and 7/3676 (0.19%) <50. In multivariate analysis older pts were significantly more likely to have WBC < 1000/cmm, any G4 hematologic toxicity, or to have discontinued Cx. There were no significant differences in G3–5 non-hematologic toxicity and no deaths due to neutropenia and sepsis.The incidence of AML/MDS due to Cx significantly increased with increasing age. Conclusions: Older pts who met the strict eligibility criteria for these trials had a higher incidence of Cx-related AML/MDS but not non-hematologic toxicity. It is uncertain if cardiac deaths attributed to Cx are definitely due to treatment. Except for AML/MDS, 5-year non-BC mortality, including Cx-attributed death, is similar in elders to age-adjusted rates in the normal population. Elders treated with intense but more effective ADJ regimens should be cautioned concerning the increased risks of AML/MDS. Physicians should help elders weigh the risks and benefits of ADJ treatment.

[Table: see text]

[Table: see text]

Multi-center prospective analysis of risk-reducing salpingo-oophorectomy to prevent BRCA-associated breast and ovarian cancer

1003

Background: Our groups previously reported on the efficacy of risk-reducing salpingo-oophorectomy (RRSO) for the prevention of BRCA-associated breast and ovarian cancer. (Kauff ND, et al. NEJM 2002; Rebbeck TR, et al. NEJM 2002) Limitations of those reports included relatively short prospective follow-up and lack of power to analyze the protection of RRSO when participants were stratified by BRCA1 vs. BRCA2. To address these limitations, we have pooled our updated datasets to provide robust estimates of the efficacy of RRSO. Methods: 886 women ≥ 30 years of age, with a deleterious mutation in BRCA1 or BRCA2 and ovaries in-situ at time of genetic test results, were enrolled on prospective follow-up studies at one of eleven centers from 11/1/1994 - 12/1/2004. Women chose to participate in either ovarian surveillance or undergo RRSO. Follow-up information was collected by questionnaire and medical record review. Follow-up time was counted from time of RRSO or from time of genetic test results for women who did not undergo RRSO. After excluding cancers diagnosed within the first 6 months of follow-up, the effect of RRSO on time to diagnosis of breast or BRCA-associated gynecologic cancer was analyzed using a Cox proportional-hazards model. Results: 559 (63%) participants underwent RRSO a median of 5 months after genetic test results. 12 occult ovarian or fallopian tube cancers were diagnosed at time of RRSO. During a mean 40 months follow-up, RRSO was associated with a 52% reduction in breast cancer risk and a 91% reduction in ovarian cancer risk (see Table ). When the cohort was stratified by mutation status, RRSO was associated with a reduced risk of BRCA1-associated ovarian cancer and BRCA2-associated breast cancer. Conclusions: The results confirm that RRSO is highly protective against BRCA-associated breast and ovarian cancer. These results also generate the hypothesis that the protection conferred by RRSO against specific cancers may differ between carriers of BRCA1 and BRCA2 mutations.

[Table: see text]

No significant financial relationships to disclose.

Letrozole (L) with bevacizumab (B) is feasible in patients (pts) with hormone receptor-positive metastatic breast cancer (MBC)

3050

Background: Bevacizumab added to chemotherapy (CRx) prolongs PFS in pts with MBC. Data suggest that estrogen (E2) modulates VEGF-induced angiogenesis in physiologic and pathologic conditions. E2-induced VEGF expression may promote breast cancer growth therefore combination therapy with an aromatase inhibitor (AI) and an antibody to VEGF may be more effective than either agent alone. We performed a feasibility study testing B with L for the treatment (tx) of hormone receptor-positive MBC. Methods: Eligible pts have MBC and are candidates for AI therapy. Prior non-steroidal AI (NSAI) use without progression is permitted. Premenopausal pts undergo ovarian suppression/oophorectomy prior to tx. Therapy consists of L (2.5 mg daily) and B (15 mg/kg IV q3 weeks). The primary endpoint is frequency of Grade (Gr) 4 toxicity. Secondary endpoints include response rate, stable disease (SD) ≥ 6 mo and time to tumor progression. Using a two-stage design, 19 pts were accrued. Because <3 pts had Gr 4 toxicity, the 2nd stage is now enrolling an additional 23 pts. If <5 of the 42 pts have Gr 4 toxicity, the regimen will be considered feasible. Results: Thirty two pts are currently accrued and 28 are now evaluable. Medians: Age 49.5 yrs (32–77) and ECOG PS 0 (0–1). Sites of MBC: bone only 11/28, visceral 16/28, chest wall/soft tissue/lymph nodes 11/28. All are ER and/or PR (+); none are HER2 (+). Prior therapy: adjuvant CRx 20; adjuvant tamoxifen 14. Twenty five pts received an NSAI as first-line tx of MBC, starting a median of 23 wks (1–213) before B. Three pts received first-line tamoxifen; one pt had prior CRx for MBC. After a median of 8 cycles (1–20), tx-related toxicities: Gr 2: hypertension (HTN) 4, headache (HA) 4, proteinuria 3, fatigue 6, joint pain 5, hot flashes 1, epistaxis 1; Gr 3: HTN 5, HA 1, proteinuria 1. There has been no tx-related Gr 4/5 toxicity. Tx-related withdrawals: HTN 1 and headache 1. Twenty five pts are evaluable for response: PR 2, SD ≥ 6 mo 13, SD 4, progression 6. Conclusions: Combination L and B is well tolerated and will be studied in a randomized CALGB trial. Circulating endothelial and tumor cell data is reported separately. Supported in part by Genentech and Novartis.

[Table: see text]

Expression of osteoprotegerin (OPG), TNF related apoptosis inducing ligand (TRAIL), and receptor activator of nuclear factor kappaB ligand (RANKL) in human breast tumours

BACKGROUND

Osteoprotegerin (OPG) is involved in the regulation of bone turnover through binding to the receptor activator of nuclear factor kappaB ligand (RANKL), and has also been reported to be a potential survival factor for several different cell types. The survival effects are mediated through inhibition of the activity of tumour necrosis factor related apoptosis inducing ligand (TRAIL). Both breast and prostate cancer cells produce sufficient amounts of OPG to be protected against the effects of TRAIL in vitro.

AIMS

To investigate the spatial expression of OPG, RANKL, and TRAIL in non-neoplastic breast tissue and breast cancer, and its relation with oestrogen receptor (ER) expression.

METHODS

Forty breast cancers (20 ER+, 20 ER-) and five non-neoplastic breast tissue samples were stained with antibodies against OPG, RANKL, and TRAIL.

RESULTS

OPG was not expressed in non-neoplastic breast tissue except when colocalised with altered columnar epithelium. RANKL was expressed at the apical surface of luminal epithelial cells and TRAIL was expressed in myoepithelial cells. All three proteins were expressed in some breast cancers but showed no significant association with tumour type. OPG expression showed a significant positive correlation with ER expression (p = 0.011).

CONCLUSIONS

This is the first published study of the spatial expression of OPG, RANKL, and TRAIL in breast tissue and breast cancer. The localisation of each protein was specific and they were not colocalised. This specificity may provide a useful marker of functional differentiation in breast cancer; for example, TRAIL expression as a marker of myoepithelial differentiation.

Results of 58872 and 58921 trials in acute myeloblastic leukemia and relative value of chemotherapy vs allogeneic bone marrow transplantation in first complete remission: the EORTC Children Leukemia Group report

The first EORTC (European Organization of Research and Treatment of Cancer) acute myeloblastic leukemia (AML) pilot study (58872) was conducted between January 1988 and December 1991. Out of 108 patients, 78% achieved complete remission (CR), and event-free survival (EFS) and survival rates (s.e., %) at 7 years were 40 (5) and 51% (6%), respectively. It indicated that mitoxantrone could be substituted for conventional anthracyclines in the treatment of childhood AML without inducing cardiotoxicity. The aim of the next EORTC 58921 trial was to compare the efficacy and toxicity of idarubicin vs mitoxantrone in initial chemotherapy courses, further therapy consisting of allogeneic bone marrow transplantation (alloBMT) in patients with an HLA-compatible sibling donor or chemotherapy in patients without a donor. Out of 177 patients, recruited between October 1992 and December 2002, 81% reached CR. Overall 7-year EFS and survival rates were 49 (4) and 62% (4%), respectively. Out of 145 patients who received the first intensification, 39 had a sibling donor. In patients with or without a donor, the 7-year disease-free survival (DFS) rate was 63 (8) and 57% (5%) and the 7-year survival rate was 78 (7) and 65% (5%), respectively. Patients with favorable, intermediate and unfavorable cytogenetic features had a 5-year EFS rate of 57, 45 and 45% and a 5-year survival rate of 89, 67 and 53%, respectively.

Evidence for secular trends in children's physical activity behaviour

It is not clear whether the global increase in weight problems in children is the result of excessive energy intake or decreasing energy expenditure. Methodological limitations have made it difficult to analyse. There is evidence that at least part of the problem may lie with increasing energy consumption, but it is important to examine the other side of the energy equation also. However, it is not possible to conclusively describe physical activity trends because of the absence of suitable baseline data. One solution is to summate all available evidence in as many areas of daily activities as possible and then draw tentative conclusions. This review summarises available trend data on direct representations of physical activity in a range of contexts, together with indirect measures such as sedentariness, fitness, and attitudes. The conclusions drawn are: physical activity in clearly defined contexts such as active transport, school physical education, and organised sports is declining in many countries; young people would like to be active but are often constrained by external factors such as school policy or curricula, parental rules in relation to safety and convenience, and physical environmental factors.

Serum HER2 extracellular domain in metastatic breast cancer patients treated with weekly trastuzumab and paclitaxel: association with HER2 status by immunohistochemistry and fluorescence in situ hybridization and with response rate

PURPOSE

We explored the relationship between circulating HER2 extracellular domain (ECD) and tissue HER2 status as determined by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). We also examined its predictive value in a cohort of metastatic breast cancer patients treated with weekly trastuzumab and paclitaxel.

METHODS

Eligible patients had pre- and post-treatment stored serum specimens and were treated on a previously reported phase II trial. Retrospective analysis evaluated: the association between pretreatment serum HER2 ECD and tissue HER2 status by IHC and FISH; and the association between change in serum HER2 ECD after 12 weeks of therapy and response proportion.

RESULTS

Stored serum samples were available for 55/95 (58%) patients. Statistically significant associations were found between HER2 status as assessed by IHC and FISH, and baseline serum HER2 ECD level. Patients whose ECD normalized after 12 weeks of therapy had a higher response proportion compared with patients with persistently high ECD levels (68% versus 15%, P=0.005). A relative decline of over 55% from baseline HER2 ECD predicted response to therapy.

CONCLUSION

A statistically significant association was observed between pretreatment serum HER2 ECD and tissue HER2 status as assessed by IHC and FISH. A decrease in serum HER2 ECD level was a significant predictor of response to trastuzumab-based therapy.