Oral minoxidil for the treatment of late alopecia in cancer survivors

12022

Background: Late alopecia is defined as incomplete hair regrowth > 6 months following cytotoxic chemotherapy or from initiation of endocrine therapy. It has been reported in up to 25-30% of cancer survivors and is associated with decreased quality of life and reduced dose intensity of cancer therapies. Minoxidil is an aminopyridine potassium channel opener, resulting in vasodilation and premature entry of resting hair follicles into the anagen (growth) phase and increase in hair follicle size. This study aims to assess clinical outcomes and adverse events of oral minoxidil for the treatment of cancer therapy-related late alopecia. Methods: We retrospectively assessed all women with late alopecia treated with oral minoxidil (1.25 mg daily) evaluated at an oncodermatology referral program between 1/2018-5/2021. Outcomes were assessed by standardized photography (4 views) and trichoscopy (HairMetrix, Canfield Scientific, Inc.). Trichoscopy recorded hair density (hair count/cm2) and hair thickness (shaft diameter) at uniform frontal and occipital target areas (12 and 36 cm midline from the glabella, respectively). Adverse events were recorded and graded using CTCAE v5.0. Descriptive statistics were used to summarize the patient demographics and clinical characteristics. Changes in trichoscopy measurements from baseline to follow-up were estimated using paired t-tests. Results: Two hundred and sixteen patients (mean age 57.8±13.7) were included for analysis. Thirty-one (14%) received chemotherapy alone, 65 (30%) endocrine monotherapy, and 120 (56%) chemotherapy followed by endocrine therapy. The majority of patients (n = 170, 79.1%) had a history of breast cancer. Standardized photography assessments (n = 119) after a median of 105 days (IQR = 70) on oral minoxidil revealed clinical improvement in 88 (74%). Trichoscopy assessments (n = 42) after a median of 91 days (IQR = 126) demonstrated increased frontal hair density (124.2 vs 153.2 hairs/cm2, p = 0.008) and occipital hair density (100.3 vs 123.5 hairs/cm2, p = 0.004). There was no statistically significant difference in average frontal or occipital hair thickness (69.3 vs 67.3 μm, p = 0.22, and 70.3 vs 69.9 μm, p = 0.84, respectively). No patients reported discontinuation of oral minoxidil due to adverse effects. Conclusions: Oral minoxidil may benefit both frontal and occipital late alopecia in cancer survivors treated with cytotoxic and/or endocrine therapy. This regimen was well tolerated by patients. Prospective, controlled studies are needed to confirm these observations.

A Phase I Study of Alpelisib in Combination with Trastuzumab and LJM716 in Patients with PIK3CA-Mutated HER2-Positive Metastatic Breast Cancer

PURPOSE

Activating mutations in PIK3CA promote resistance to HER2-targeted therapy in breast cancer; however, inhibition of PI3K alone leads to escape via feedback upregulation of HER3. Combined inhibition of HER2, HER3, and PI3K overcomes this mechanism preclinically.

PATIENTS AND METHODS

This phase I study investigated the MTD of alpelisib given in combination with trastuzumab and LJM716 (a HER3-targeted antibody) in patients with PIK3CA-mutant HER2-positive (HER2+) metastatic breast cancer (MBC) using the continual reassessment method. Secondary analyses included efficacy and exploratory correlative studies.

RESULTS

Ten patients were treated initially with daily alpelisib (arm A). Grade ≥3 adverse events seen in ≥2 patients included diarrhea (n = 6), hypokalemia (n = 3), abnormal liver enzymes (n = 3), hyperglycemia (n = 2), mucositis (n = 2), and elevated lipase (n = 2). The MTD of alpelisib in arm A was 250 mg daily. This prompted the opening of arm B in which 11 patients received intermittently dosed alpelisib. Grade ≥3 adverse events seen in ≥2 patients included diarrhea (n = 5), hypokalemia (n = 3), and hypomagnesemia (n = 2). The MTD of alpelisib in arm B was 350 mg given 4 days on, 3 days off. Among 17 patients assessed, 1 had a partial response, 14 had stable disease, and 2 had disease progression at best response. Five patients had stable disease for >30 weeks. mRNA profiling of pre- and on-treatment tissue demonstrated PIK3CA target engagement by alpelisib via induction of downstream signaling and feedback pathways.

CONCLUSIONS

Combination treatment with alpelisib, trastuzumab, and LJM716 was limited by gastrointestinal toxicity. Further efforts are warranted to target the PI3K pathway in HER2+ MBC.

Vertebral Fractures After Denosumab Discontinuation in Breast Cancer Survivors: A Single Institution Experience

Background: Denosumab is approved to prevent fragility fractures in patients with osteoporosis at high risk for fracture and to prevent bone loss in patients with breast and prostate cancer who receive endocrine therapy. The antiresorptive effect of denosumab rapidly dissipates when it is delayed or discontinued, but the risk for, and incidence of, multiple clinical vertebral fractures in patients with breast cancer after stopping denosumab is currently unclear. Question/Purposes: We sought to identify the incidence of clinical vertebral fractures in patients with breast cancer who received at least 2 doses of denosumab (60 mg) and then discontinued the medication. Methods: We conducted a retrospective chart review to identify patients with a history of breast cancer who were treated with denosumab between June 1, 2010, and July 18, 2018, at Memorial Sloan Kettering Cancer Center. We identified 335 postmenopausal women and 1 man with nonmetastatic breast cancer who received their final denosumab injection at least 6.5 months earlier. Data recorded included baseline bone density and the incidence of vertebral fractures after denosumab discontinuation. Results: The median age of patients was 62 years. Patients received between 2 and 13 denosumab doses before drug discontinuation. Most of the patients (310; 92.3%) were also treated with aromatase inhibitors. Of the 194 patients with baseline bone density data, 50 (25.8%) had normal bone density, 97 (50.0%) had osteopenia, and 47 (24.2%) had osteoporosis. The median follow-up duration from the last denosumab dose was 18.5 months. We identified 1 case of spontaneous vertebral fractures after denosumab stoppage. We found no cases of osteonecrosis of the jaw or atypical femur fracture. Most of the patients (88%) had a gap in denosumab dosing. Conclusions: Clinicians treating patients with breast cancer-especially those continuing to take aromatase inhibitors-should be aware of the possible risks of delaying doses of or discontinuing denosumab and should educate their patients accordingly. Prospective studies are needed to fully evaluate the risks of stopping or delaying denosumab.

A phase II trial of cabozantinib in hormone receptor-positive breast cancer with bone metastases

1062

Background: We assessed the antitumor activity of cabozantinib, a potent multi-receptor oral tyrosine kinase inhibitor with activity against MET, RET, VEGFR2, and AXL, in patients with hormone-receptor positive (HR+) breast cancer with bone metastases. Methods: In this single-arm multicenter phase II study, patients with HR+, HER2- metastatic breast cancer and ≥ 1 prior line of therapy received an initial starting dose of 100 mg cabozantinib, later reduced to 60 mg per day. The primary endpoint was bone scan response rate determined by independent central review and defined as percent change of bone scan area from baseline. The target bone scan response rate was 30% compared to a null response rate of 10%. Secondary endpoints included objective response rate (ORR) by RECIST v1.1, progression free (PFS) and overall survival (OS). Bone scan and CT were obtained every 12 weeks. Results: Among 52 enrolled patients, median age was 55, and 54% and 42% had > 2 lines prior endocrine and chemotherapy, respectively and 18 (35%) had bone-only disease. 20 (38%) experienced a partial bone scan response and 6 (12%) had stable disease (SD). 16 (31%) patients discontinued study prior to week 12 assessment for early clinical progression or toxicity, and three (6%) had missing follow-up scans. Best extra-osseous overall response revealed SD in 26 (50%), but no objective responses. In 25 patients with bone scan disease control at 12 weeks, only 3 (12%) developed extra-osseous progression. Median PFS was 4.3 months (90% CI 2.8 - 5.5) and OS was 19.6 months (90% CI 18.0 – 26.8). In a landmark analysis, patients with bone scan disease control at 12 weeks had longer OS (median 24.2 months, 90% CI 16.4 – 31.7) than those without (median OS 13.3 months, 90% CI 9.5 – 18.2), with a hazard ratio of 0.37 (90% CI 0.21 – 0.65). Most common grade 3 or 4 toxicities were hypertension (10%), anorexia (6%), diarrhea (6%), fatigue (4%) and hypophosphatemia (4%). Dose reduction or delay occurred in 42 (81%) patients. Conclusions: This study met its primary endpoint with bone scans improved in 38% of patients with metastatic HR+ breast cancer and remained stable in an additional 12% with cabozantinib treatment. Bone scan response correlated with improved OS. This is the first reported study in breast cancer to use bone scan response as a primary endpoint. Further studies with cabozantinib in HR+ breast cancer and additional validation of bone scan response as a surrogate for clinical benefit in breast cancer are warranted. Clinical trial information: NCT01441947 .

Efficacy and Safety of Gemcitabine With Trastuzumab and Pertuzumab After Prior Pertuzumab-Based Therapy Among Patients With Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer: A Phase 2 Clinical Trial

IMPORTANCE

Taxanes with trastuzumab and pertuzumab for initial treatment of human epidermal growth factor receptor 2 (ERBB2, formerly HER2)-positive metastatic breast cancer is associated with improved progression-free survival (PFS) and overall survival. While continued use of trastuzumab in therapeutic combinations after disease progression is standard, the efficacy of continuing pertuzumab is unknown.

OBJECTIVE

To evaluate the efficacy and safety of pertuzumab in combination with gemcitabine and trastuzumab after prior treatment with pertuzumab for ERBB2-positive metastatic breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This is a phase 2 single-arm clinical trial of dual anti-ERBB2 therapy after prior treatment with pertuzumab. The study took place at a single academic center from March 2015 to April 2017 among women with ERBB2-positive metastatic breast cancer, prior pertuzumab-based treatment, and 3 or fewer prior chemotherapy regimens. Data were analyzed between January 2019 and March 2019.

INTERVENTION

Treatment consisted of gemcitabine, 1200 mg/m2 (later amended to 1000 mg/m2) on days 1 and 8 every 3 weeks, plus trastuzumab (8-mg/kg loading dose, then 6 mg/kg) and pertuzumab (840-mg loading dose, then 420 mg) once every 3 weeks.

MAIN OUTCOMES AND MEASURES

The primary end point was 3-month PFS. Based on prior trials, a target rate of 70% or higher was selected as the promising progression-free rate at 3 months. Secondary outcomes included safety, tolerability, and overall survival.

RESULTS

A total of 45 patients (median [range] age, 57.1 [31.7-77.2] years) were enrolled; 22 (49%) were treated in the second-line setting, and 23 (51%) were treated in the third-line setting or beyond. Of these, 22 (49%) received prior trastuzumab emtansine (T-DM1). At a median (range) follow-up of 27.6 (8.3-36.0) months, 3-month PFS was 73.3% (95% CI, 61.5%-87.5%). Overall, median PFS was 5.5 months (95% CI, 5.4-8.2 months). Treatment was well tolerated, with no occurrences of febrile neutropenia or symptomatic left ventricular systolic dysfunction.

CONCLUSIONS AND RELEVANCE

In this phase 2 trial, treatment with gemcitabine, trastuzumab, and pertuzumab after prior pertuzumab-based therapy for ERBB2-positive metastatic breast cancer was associated with a 3-month PFS rate of 73.3% and was well tolerated. Continuation of pertuzumab beyond progression was associated with apparent clinical benefit.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02252887.

Phase II Study of Paclitaxel and Dasatinib in Metastatic Breast Cancer

BACKGROUND

Overexpression and activation of tyrosine kinase Src has been linked to breast carcinogenesis and bone metastases. We showed the feasibility of combining the SRC inhibitor dasatinib with weekly paclitaxel in patients with metastatic breast cancer (MBC) and herein report the subsequent phase II trial.

PATIENTS AND METHODS

Patients had received ≤ 2 chemotherapy regimens for measurable, HER2-negative MBC. Patients received paclitaxel and dasatinib (120 mg daily) and were assessed according to Response Evaluation Criteria in Solid Tumors for overall response rate (ORR), the primary end point. Secondary end points included progression-free survival (PFS) and overall survival (OS). A 30% ORR (n = 55) was deemed worthy of further investigation. Exploratory biomarkers included N-telopeptide (NTX) and plasma vascular epidermal growth factor (VEGF) receptor 2 as predictors of clinical benefit.

RESULTS

From March 2010 to March 2014, 40 patients, including 2 men enrolled. The study was stopped early because of slow accrual. Overall, 32 patients (80%) had estrogen receptor-positive tumors and 23 (58%) had previously received taxanes. Of the 35 assessable patients, 1 (3%) had complete response and 7 (20%) partial response, resulting in an ORR of 23%. The median PFS and OS was 5.2 (95% confidence interval [CI], 2.9-9.9) and 20.6 (95% CI, 12.9-25.2) months, respectively. As expected, fatigue (75%), neuropathy (65%), and diarrhea (50%) were common side effects, but were generally low-grade. Median baseline NTX was similar in patients who had clinical benefit (8.2 nmol BCE) and no clinical benefit (10.9 nmol BCE). Similarly, median baseline VEGF levels were similar between the 2 groups; 93.0 pg/mL versus 83.0 pg/mL.

CONCLUSION

This phase II study of dasatinib and paclitaxel was stopped early because of slow accrual but showed some clinical activity. Further study is not planned.

Phase II study of gemcitabine (G), trastuzumab (H), and pertuzumab (P) for HER2-positive metastatic breast cancer (MBC) after prior pertuzumab-based therapy

1037

Background: The combination of taxanes with HP for first line treatment of HER2-positive MBC is associated with improved progression-free (PFS) and overall survival (OS). Treatment per physician’s choice with anti-HER2 therapy after second line therapy is associated with a median PFS of 3 months. While continued use of H in therapeutic combinations after progression on H-based therapy is standard, the efficacy of continuing HP-based treatment after progression on P-based therapy is unknown. Methods: This is a single arm phase II trial of G with HP. Eligible patients (pts) had HER2-positive (IHC 3+ or FISH > 2.0) MBC with prior HP-based treatment and ≤ 3 prior chemotherapies. Pts received G (1200 mg/m2) on days 1 and 8 of a q 3 week (w) cycle, and H (8 mg/kg load → 6 mg/kg) and P (840 mg load → 420 mg) q3w. The primary endpoint is PFS at 3 months. Secondary endpoints include OS, safety and tolerability. An exploratory endpoint is to compare PFS by RECIST criteria versus 18-F FDG-PET response criteria. The study therapy will be considered successful if at least 27/45 (60%) patients are progression free at 3 months. Results: As of 1-27-17, 41 of 45 pts are enrolled; 34 are evaluable at 3 months and 7 have not had 3-month evaluation. At 3 months, 26/34 (76%) are progression free (1 CR, 8 PR, 17 SD); 8 pts progressed. There are no cardiac or febrile neutropenic events to date. 4 pts required G dose reduction (3 grade 3 neutropenia and 1 grade 3 vomiting) and the study was amended to lower initial G dose to 1000 mg/m2. Conclusions: The preliminary 3 month-PFS is 76% in evaluable pts (95% CI 60% to 88%). The updated 3 month-PFS results will be presented. Continuation of P beyond progression is associated with apparent clinical benefit. A randomized trial is justified to confirm this clinically important observation. Clinical trial information: NCT02252887.

Abstract P4-21-34: Phase II study of gemcitabine, trastuzumab, and pertuzumab for HER2-Positive metastatic breast cancer after prior pertuzumab-based therapy

Background: The combination of taxanes with trastuzumab (H) and pertuzumab (P) for first line treatment of HER2-positive metastatic breast cancer (MBC) is associated with improved progression-free survival (PFS) and overall survival (OS). Treatment per physician's choice with anti-HER2 therapy after second line therapy is associated with a median PFS of 3 months. While continued use of H in therapeutic combinations after progression on H-based therapy is common, the efficacy of continuing HP-based treatment after progression on P-based therapy is unknown.

Methods: This is a single arm phase II trial of gemcitabine (G) with HP. Eligible patients had HER2-positive (IHC 3+ or FISH ≥ 2.0) MBC with prior HP-based treatment and ≤ 3 prior chemotherapies. Patients received G (1200 mg/m2) on days 1 and 8 of a q 3 week (w) cycle, and H (8 mg/kg load → 6 mg/kg) and P (840 mg load → 420 mg) q3w. The primary endpoint is PFS at 3 months. Secondary endpoints include OS, safety and tolerability. An exploratory endpoint is to compare PFS by RECIST criteria versus 18-F FDG-PET response criteria. Using a Simon optimal 2-stage design, 21 patients were enrolled in stage 1. The successful 3-month PFS rate for stage 1 was set at 57% to allow accrual to stage 2 for a total of 45 patients. The study therapy will be considered successful if at least 27/45 (60%) patients are progression free at 3 months.

Results: As of June 9, 2016, 28 patients are enrolled; 21 are evaluable at 3 months and 7 have not had 3-month evaluation. At 3 months, 16/21 (76%) are progression free; 5 patients have progressed. The 3 month-PFS results for evaluable patients will be updated. There are no cardiac or febrile neutropenic events to date. Initially, 5 of 22 (23%) patients required G dose reduction (4 due to grade 3 neutropenia and 1 due to grade 3 vomiting) and the study was amended to lower initial G dose to 1000 mg/m2.

Conclusions: The preliminary 3 month-PFS is 76% (95% CI 55% to 89%) in evaluable patients, and updated data will be presented. These findings suggest clinical benefit when P is continued beyond progression.

Citation Format: Iyengar NM, Smyth L, Lake D, Gucalp A, Singh JC, Traina TA, DeFusco P, Dickler MN, Fornier MN, Goldfarb S, Jhaveri K, Modi S, Troso-Sandoval T, Argolo D, Jack K, Ulaner G, Jochelson M, Baselga J, Norton L, Hudis CA, Dang CT. Phase II study of gemcitabine, trastuzumab, and pertuzumab for HER2-Positive metastatic breast cancer after prior pertuzumab-based therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-34.

Assessing fracture risk in early stage breast cancer patients treated with aromatase-inhibitors: An enhanced screening approach incorporating trabecular bone score

Introduction

Aromatase-inhibitors (AIs) are commonly used for treatment of patients with hormone-receptor positive breast carcinoma, and are known to induce bone density loss and increase the risk of fractures. The current standard-of-care screening tool for fracture risk is bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA). The fracture risk assessment tool (FRAX®) may be used in conjunction with BMD to identify additional osteopenic patients at risk of fracture who may benefit from a bone-modifying agent (BMA). The trabecular bone score (TBS), a novel method of measuring bone microarchitecture by DXA, has been shown to be an independent indicator of increased fracture risk. We report how the addition of TBS and FRAX®, respectively, to BMD contribute to identification of elevated fracture risk (EFR) in postmenopausal breast cancer patients treated with AIs.

Methods

100 patients with early stage hormone-positive breast cancer treated with AIs, no prior BMAs, and with serial DXAs were identified. BMD and TBS were measured from DXA images before and following initiation of AIs, and FRAX® scores were calculated from review of clinical records. EFR was defined as either: BMD ≤−2.5 or BMD between −2.5 and −1 plus either increased risk by FRAX® or degraded microstructure by TBS.

Results

At baseline, BMD alone identified 4% of patients with EFR. The addition of FRAX® increased detection to 13%, whereas the combination of BMD, FRAX® and TBS identified 20% of patients with EFR. Following AIs, changes in TBS were independent of changes in BMD. On follow-up DXA, BMD alone detected an additional 1 patient at EFR (1%), whereas BMD+ FRAX® identified 3 additional patients (3%), and BMD+FRAX®+TBS identified 7 additional patients (7%).

Conclusions

The combination of FRAX®, TBS, and BMD maximized the identification of patients with EFR. TBS is a novel assessment that enhances the detection of patients who may benefit from BMAs.

Abstract P2-16-12: An exploratory analysis of the role of dasatinib in preventing progression of disease in bone in patients with metastatic breast cancer

Introduction: The role of dasatinib, an oral SRC inhibitor is being explored for the treatment of metastatic breast cancer. In a phase I study, we previously established that the combination of dasatinib and weekly paclitaxel was feasible. The activity of this combination is currently being explored in an ongoing phase II trial. Since Src kinase has a major role in osteoclast function and dasatinib has established anabolic and anti-resorptive effects in bone in vitro, we hypothesized that patients receiving this combination would have good control of osseous metastases and primarily develop progression of disease in sites other than bone.

Patients and methods: Patients were included in this analysis if they participated in the phase I or II metastatic breast cancer studies and received dasatinib at or above the recommended phase II dose of 120mg with paclitaxel (80mg/m2 day 1 and 8 of each 21day cycle). Patients who discontinued therapy for reasons other than progression were excluded. Per protocol, patients were required to discontinue bisphosphonates or other bone modulating agents for the first 8 weeks of study due to the potential for hypocalcaemia. Thereafter, they were permitted to receive these agents at the discretion of their treating physician. Patients provided serum samples for correlative studies. Assessment of N-telopeptide of type 1 collagen (NTX), a product of mature bone collagen that reflects bone specific resorption, is planned.

Results: The median age of the 24 patients who met criteria for analysis was 50y (37 - 66y). Of these, 15 (63%) had ER+ disease, and 24 (100%) were negative for human epidermal growth factor receptor (HER2). At study entry, 17 (71%) patients had bone involvement. Following the initial eight week moratorium, 7 (29%) patients received a bisphosphonate or rank ligand inhibitor during treatment with dasatinib + paclitaxel. Patients received a median 2 months (range 1-23) of dasatinib + paclitaxel therapy. To date, 3 (13%) continue on therapy, and 21 (88%) have had progression of disease. Among patients who progressed, 18 (86%) have progressed in visceral sites and only 3 (14%) progressed in bone. Analyses of serum NTX levels are ongoing and will be compared by site of progression.

Conclusion: The potential role of serum NTX as a predictive biomarker of benefit from dasatinib and paclitaxel is being explored and updated results will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-12.

Biological subtypes of breast cancer: current concepts and implications for recurrence patterns

Breast cancer is comprised of a number of complex and heterogeneous subtypes with differing clinical behavior and outcomes. In recent years, significant advances have been made in discerning the molecular drivers of this disease, and characterizing distinct subtypes of breast cancer based on gene expression profiles. These advances have begun to translate into greater individualization of treatment for patients. Although these advances have shaped our understanding of the underlying biology of breast cancer, most clinical decisions are currently based on tumor expression of the estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor receptor 2 (HER2). These biomarkers have prognostic and predictive significance in breast cancer and have important implications for tumor growth and metastatic patterns. In this review, we focus on the three broad phenotypes of breast cancer used in clinical practice; ER/PR positive, HER2 positive and triple negative breast cancer (TNBC), which is characterized by lack of expression of ER, PR and HER2. We discuss the influence of these tumor-related factors as well as histological subtype, on the potential for breast cancer recurrence and patterns of disease spread.

Increased levels of urinary PGE-M, a biomarker of inflammation, occur in association with obesity, aging, and lung metastases in patients with breast cancer

Elevated levels of COX-derived prostaglandin E2 (PGE2) occur in inflamed tissues. To evaluate the potential links between inflammation and breast cancer, levels of urinary prostaglandin E metabolite (PGE-M), a stable end metabolite of PGE2, were quantified. We enrolled 400 patients with breast cancer: controls with early breast cancer (n = 200), lung metastases (n = 100), and metastases to other sites (n = 100). Patients completed a questionnaire, provided urine, and had measurements of height and weight. Urinary PGE-M was quantified by mass spectrometry. Ever smokers with lung metastasis who had not been exposed to nonsteroidal anti-inflammatory drugs (NSAIDs) had the highest PGE-M levels. PGE-M levels were increased in association with elevated body mass index (BMI; P < 0.001), aging (P < 0.001), pack-year smoking history (P = 0.02), lung metastases (P = 0.02), and recent cytotoxic chemotherapy (P = 0.03). Conversely, use of NSAIDs, prototypic inhibitors of COX activity, was associated with reduced PGE-M levels (P < 0.001). On the basis of the current findings, PGE-M is likely to be a useful biomarker for the selection of high-risk subgroups to determine the use of interventions that aim to reduce inflammation and possibly the development and progression of breast cancer, especially in overweight and obese women.

Abstract P5-20-07: Phase II Trial of Dasatinib in Combination With Weekly Paclitaxel for Patients with Metastatic Breast Carcinoma

Background: Src kinase plays an important role in proliferation, survival, angiogenesis and metastasis in several malignancies including breast cancer. Therefore, inhibition of Src and other tyrosine kinases (TKs) represents a novel therapeutic approach. Dasatinib is a potent inhibitor of 5 oncogenic TKs, inhibits VEGF-stimulated proliferation, has potent bone anti-resorptive activity and selectively inhibits basal-type breast cancer growth. Preclinically, the combination of dasatinib and paclitaxel had superior antitumor activity to either agent alone. In a previous phase I study, we determined that, in combination with weekly paclitaxel, the optimum dose of dasatinib was 120mg. Of note, 4/9 (44%) patients treated at or above this dasatinib dose level had objective tumor response. We now present results from the phase II trial of this combination.

Methods: Patients with MBC, ECOG PS 0–1, normal hepatic, renal, marrow function were eligible. Patients had measurable, HER2-negative metastatic breast cancer (MBC), ≤2 prior therapies for MBC. Treatment consisted of weekly paclitaxel 80 mg/m2 IV 3/4 weeks + Dasatinib 120mg orally daily. Response was assessed by RECIST after every 8 weeks of therapy. Simon's two-stage optimal design was used to test the null hypothesis of a 15% response rate (RR) against the alternative of a 30% RR. In stage I, planned enrollment was 23 patients based on Type I and Type II errors of 10%. If 4 or more responses are observed, enrollment will be extended to 55 patients. Exploratory correlative biomarkers of clinical benefit include Src phosphorylation (p-Src) in peripheral blood mononuclear cells, plasma levels of VEGFR2 and collagen Type IV, circulating tumor cells (CTCs) and tumor gene expression profiling.

Results: 21 patients (19 females, 2 male) have enrolled; median age 48 (range 30–79). Patients received a median of 1 prior therapy for MBC (range 0–2). 6 patients are not assessable for response: 1 has received &lt;8 weeks treatment, 5 came off study for toxicity (2 hypersensitivity reaction to paclitaxel, 1 infection, 1 diarrhea/nausea, 1 bleeding likely related to anticoagulation). Among the 15 patients assessable for response, best response to date is as follows: 2 (13%) patients partial response, 11 (73%) patients stable disease (SD) and 2 (13%) patients progression of disease. Of patients with SD, 6/11 (55%) continue on treatment after median of 2 months (range 2–10) and 5/11 (45%) patients have come off study after median of 10 months (range 3–21). Most toxicities have been hematological and low grade. Diarrhea and neuropathy have generally been low grade and no new toxicities related to the combination have occurred since expansion into the phase II. Potential biomarkers of clinical benefit including, p-Src, VEGFR2, collagen Type IV, and CTCs will be presented.

Conclusion: Data from this phase II has demonstrated preliminary evidence of activity for weekly paclitaxel and dasatinib 120mg in patients with MBC. These findings are consistent with data from this dose level in the earlier phase I study. Predictive biomarkers of clinical benefit are under investigation.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-20-07.

Ixabepilone-associated peripheral neuropathy: data from across the phase II and III clinical trials

PURPOSE

Dose-limiting neuropathy is a major adverse event associated with most of the microtubule-stabilizing agent-based chemotherapy regimens. Ixabepilone, a semisynthetic analogue of the natural epothilone B, has activity against a wide range of tumor types. Peripheral neuropathy (PN), associated with ixabepilone treatment, is usually mild to moderate, predominantly sensory and cumulative. Preclinical studies demonstrate that ixabepilone and taxanes produce a similar neurotoxicity profile.

METHODS

We searched databases of phase II/III clinical trials involving patients receiving ixabepilone as a monotherapy or in combination with capecitabine for incidences of neuropathy. Potential risk factors for grade 3/4 PN were identified by a Cox regression analysis on a dataset of 1,540 patients with different tumor types across multiple studies.

RESULTS

Rates for incidence of ixabepilone-induced severe PN (Common Terminology Criteria for Adverse Events grade 3/4) ranged from 1% in early untreated breast cancer up to 24% in heavily pretreated metastatic breast cancer; grade 4 PN was rare (≤ 1%). Common symptoms included numbness, paresthesias, and sometimes dysesthesias. Cox regression analysis identified only preexisting neuropathy as a risk factor for increased ixabepilone-associated PN. The management of PN has been primarily through dose adjustments (dose delays and/or dose reduction). Patients had resolution of their neuropathy within a median time of 5 to 6 weeks.

CONCLUSIONS

PN is a dose-limiting toxicity associated with ixabepilone treatment, is reversible in most patients, and can be managed with dose reduction and delays.

P4-16-06: Expression Patterns of Receptor Activator of Nuclear Factor-kB (RANK) and Src in a Series of Primary Breast Tumors (BT) and Bone Metastases (BM) in Patients (pts) with Metastatic Breast Cancer (MBC)

Background

BM develops in 65–70% of pts with MBC. RANK and its ligand (RANK-L) can be critical in the development and progression of BM. Src overexpression and deregulation occurs in many solid tumors but it has not been fully characterized although an association between Src activity defined by a gene expression signature and BM particularly in ER+ pts has been described. (Zhang XH et al. Cancer Cell. 2009) Our goal was to elucidate the relationship between Src and RANK expression in BT and BM in relation to estrogen-/progesterone-receptor (ER/PR)/HER2 expression and tumor histology (invasive ductal carcinoma (IDC) vs invasive lobular carcinoma (ILC)).

Methods: Immunohistochemistry (IHC) for RANK (R&D Systems clone 80707) and Src (Cell Applications Inc. Phospho Tyr-416) protein expression was performed on archived paraffin embedded BT and BM. Scoring: 0=negative, 1+=weak, 2+=intermediate, 3+=strong and the percent of positive tumor cells; RANK+ = 2–3+, &gt; 1% of cells; Src+ = 1–3+; &gt; 1% of cells. Associations between RANK/Src expression and tumor characteristics were assessed using the chi-square test or McNemar's test for pairs, as appropriate.

Results: From the MSKCC database, using an IRB-approved waiver of consent, we identified 54 pts with MBC who underwent surgical biopsy of a metastatic bone lesion at our center between 2005–2010, and had tissue available for further testing. 17 corresponding BT samples were identified. At the time of diagnosis, 43 (79.5%) primary tumors were ER or PR (+); 6 (11%) were HER2+; 41 (76%) were invasive ductal carcinoma. 87% of BM expressed RANK and 44% expressed Src. (Table 1) No significant correlation between RANK or Src expression in BM and ER/PR/HER2 status of BT was observed. A significant correlation between RANK expression and BT histology was observed, (p=0.0016): 93% of IDC were RANK (+), in comparison to 50% of invasive lobular carcinomas. RANK expression was not significantly different between primary tumor and metastatic bone samples (p=0.99). There was a borderline significant difference in Src expression between primary and metastatic site (p=.06).

Approved agents for metastatic breast cancer

The US Food and Drug Administration has approved three agents for treatment of patients with metastatic breast cancer refractory to anthracyclines and taxanes: capecitabine, ixabepilone, and eribulin mesylate. There is no fixed algorithm of therapeutic choices. Median survival remains measured in months, not years. Individual patient performance status, toxicity (to past regimens and any residual toxicity), preferences, and quality of life are factors in determining optimal treatment options for metastatic breast cancer. Ongoing research is seeking to improve outcomes in this patient population.

A phase I study of dasatinib and weekly paclitaxel for metastatic breast cancer

BACKGROUND

SRC plays an important role in the pathogenesis of metastatic breast cancer (MBC). In preclinical models, paclitaxel and the oral SRC inhibitor dasatinib showed greater antitumor activity than either agent. To determine the maximum tolerated dose of this combination, we conducted a phase I study.

PATIENTS AND METHODS

Patients with MBC; Eastern Cooperative Oncology Group performance status of zero to one; normal hepatic, renal and marrow function were eligible. Paclitaxel 80 mg/m(2) was given 3 weeks of 4. The starting dasatinib dose was 70 mg and was increased, using a standard 3 + 3 dose-escalation scheme.

RESULTS

Fifteen patients enrolled (median age 54 years, range 35-74). No dose-limiting toxic effects (DLTs) occurred at dasatinib doses of 70-120 mg. One DLT (grade 3 fatigue) occurred in the dasatinib 150-mg cohort, which was expanded (six patients) with no further DLTs. However, due to cumulative toxic effects (rash, fatigue, diarrhea), the recommended phase II dose is dasatinib 120 mg. Of 13 assessable patients, a partial response was seen in 4 patients (31%), including 2 patients previously treated with taxanes; all received ≥120 mg dasatinib. An additional five patients (29%) had stable disease.

CONCLUSION

In combination with weekly paclitaxel, the recommended phase II dose of dasatinib is 120 mg daily and preliminary activity has been seen in patients with MBC.

Algorithms for the treatment of patients with metastatic breast cancer and prior exposure to taxanes and anthracyclines

At present, metastatic breast cancer (MBC) remains an incurable disease, with the goals of care aimed at maximizing the patient's duration and quality of life. Treatment options for a patient with MBC have become more efficacious and numerous. In addition to endocrine and chemotherapy agents, a number of targeted agents, including trastuzumab and bevacizumab, are available. The option to use novel agents combined with a multitude of standard chemotherapies has further enhanced the landscape of therapeutic options. As such, specific regimens must be evaluated within the framework of the individual patient, answering such questions as whether to treat with sequential single agents or combination regimens as well as which agents to use and in what sequence. The concept of personalized care is even more apparent in the setting of MBC, where the goal of palliation is intrinsically more nuanced than that of curative intent. This review will broadly assess the evidence for current treatment options with attention to varying clinical scenarios. Ultimately, delivering quality of care necessitates balancing an understanding of evidence-based data with sensitive attention to quality-of-life goals.

Dose dense cyclophosphamide, methotrexate, fluorouracil is feasible at 14-day intervals: a pilot study of every-14-day dosing as adjuvant therapy for breast cancer

PURPOSE

Cyclophosphamide/methotrexate/fluorouracil (CMF) is a proven adjuvant option for patients with early-stage breast cancer. Randomized trials with other regimens demonstrate that dose-dense (DD) scheduling can offer greater efficacy. We investigated the feasibility of administering CMF using a DD schedule.

PATIENTS AND METHODS

Thirty-eight patients with early-stage breast cancer were accrued from March 2008 through June 2008. They were treated every 14 days with C 600, M 40, F 600 (all mg/m2) with PEG-filgrastim (Neulasta®) support on day 2 of each cycle. The primary endpoint was tolerability using a Simon's 2-stage optimal design. The design would effectively discriminate between true tolerability (as protocol-defined) rates of ≤ 60% and ≥ 80%.

RESULTS

The median age was 52-years-old (range, 38-78 years of age). Twenty-nine of the 38 patients completed 8 cycles of CMF at 14-day intervals.

CONCLUSION

Dose-dense adjuvant CMF is tolerable and feasible at 14-day intervals with PEG-filgrastim support.

Optimizing the use of anthracyclines in older patients with breast cancer

Recently, a greater understanding of tumor biology, including the use of genetic signatures, has led to a more precise classification of breast cancer. This has translated into a more granular assessment of risk-benefit calculations for the selection of patients for adjuvant therapies. For unselected patients, anthracyclines offer a survival benefit over non-anthracycline-based regimens, but are associated with long-term risks including congestive heart failure. Until recently, the benefit of anthracyclines in older patients with early breast cancer was largely extrapolated from studies involving younger cohorts. Emerging data now suggest that for appropriately selected older patients anthracyclines offer distinct benefits and are associated with a manageable toxicity profile. This review will focus on the benefits and risks of anthracyclines in older patients with various subtypes of breast cancer.

NCCN Task Force Report: Bone Health in Cancer Care

Bone health and maintenance of bone integrity are important components of comprehensive cancer care in both early and late stages of disease. Risk factors for osteoporosis are increased in patients with cancer, including women with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors for breast cancer, men receiving androgen-deprivation therapy for prostate cancer, and patients undergoing glucocorticoid therapy. The skeleton is a common site of metastatic cancer recurrence, and skeletal-related events are the cause of significant morbidity. The National Comprehensive Cancer Network (NCCN) convened a multidisciplinary task force on Bone Health in Cancer Care to discuss the progress made in identifying effective screening and therapeutic options for management of treatment-related bone loss; understanding the factors that result in bone metastases; managing skeletal metastases; and evolving strategies to reduce bone recurrences. This report summarizes presentations made at the meeting.

Ixabepilone and other epothilones: microtubule-targeting agents for metastatic breast cancer

Taxanes, derived from the bark of the Pacific yew tree, were the last major group of cytotoxic agents to be developed. Their proven efficacy in a variety of malignancies has constituted a real breakthrough in the treatment of cancer. Wider clinical use of taxanes has several important limitations, including acquired and intrinsic tumor resistance, hypersensitivity reactions, and cumulative neurotoxicity and hematopoietic toxicity. Epothilones, naturally occurring macrolide antibiotics that also act on the microtubule, are a novel class of compounds that may circumvent some of these problems. Many synthetic and semisynthetic epothilone analogs have been formulated and have undergone varying degrees of testing. These compounds have demonstrated activity in a variety of tumors, including in tumors and cell lines resistant to taxanes. So far only ixabepilone has been tested in phase II and III trials and licensed by the US Food and Drug Administration for the treatment of metastatic breast cancer. The main dose-limiting toxicity appears to be a sensory peripheral neuropathy, as commonly seen with drugs that act on the microtubule. Further clinical studies assessing the role of ixabepilone in other settings, as well as the clinical investigation of other epothilones, are eagerly awaited.

Microtubule active agents: beyond the taxane frontier

Microtubules are essential to cell transport, signaling, and mitosis. An increasing range of anticancer drugs interferes with the normal formation and function of microtubules. Vinca alkaloids act as microtubule destabilizers and the taxanes act as microtubule stabilizers. Taxanes are widely used cytotoxic agents that are active in a range of solid tumor malignancies and are routinely used in a variety of settings. Significant limitations with the taxanes exist, including acquired and intrinsic tumor resistance through the expression of multidrug resistance proteins such as P-glycoprotein, risk of hypersensitivity reactions, dose-limiting hematopoietic toxicity, and cumulative neurotoxicity. Hence, there is a need to develop novel agents that act on the microtubules. Epothilones are macrolide antibiotics that bind near the taxane-binding site on microtubules and have been extensively studied in recent and ongoing clinical trials. A variety of other agents that act on the microtubules at different sites with a variety of structures are at varying stages of development.

Ixabepilone, first in a new class of antineoplastic agents: the natural epothilones and their analogues

Although targeted therapies are becoming increasingly important in oncology, cytotoxic agents are likely to remain a valuable element in the treatment paradigm of cancer. However, resistance to chemotherapy is a major obstacle to the successful treatment of cancer. Therefore, there is a need for novel antineoplastic agents that are able to overcome mechanisms of tumor resistance. Drugs that target microtubules, including paclitaxel and docetaxel, are among the most commonly prescribed anticancer therapies. However, the utility of taxane-based therapies is limited by difficulties with formulation, administration, and resistance induced by P-glycoprotein. The epothilones and their analogues are a novel class of antimicrotubule agents that has demonstrated antitumor activity in the setting of resistance. These antimicrotubule agents are structurally unrelated to the taxanes, with a distinct beta-tubulin-binding mode. Ixabepilone is a rationally designed, semisynthetic analogue of natural epothilone B, which displays reduced susceptibility to a range of common tumor resistance mechanisms. Promising phase II activity and a manageable safety profile with ixabepilone have been seen in a wide range of tumor types, including heavily pretreated/resistant and early-stage breast cancer. Moreover, encouraging phase III results with ixabepilone and capecitabine for patients with breast cancer have recently been presented. Clinical trials are also planned for ixabepilone in combination with targeted agents, such as trastuzumab and bevacizumab. Ixabepilone is likely to be the first available drug in its class, with the potential to bring clinical benefit to patients with a wide range of malignancies.

Phase I dose-finding study of weekly docetaxel followed by flavopiridol for patients with advanced solid tumors

PURPOSE

Flavopiridol is a cyclin-dependent kinase inhibitor that enhances docetaxel-induced apoptosis in a sequence-specific manner. In vivo, docetaxel must precede flavopiridol by at least 4 h to induce this effect. We conducted a phase I trial of weekly, sequential docetaxel followed 4 h later by flavopiridol in patients with advanced solid tumors.

EXPERIMENTAL DESIGN

Docetaxel at a fixed dose of 35 mg/m2 was administered over 30 min, followed 4 h later by escalating doses of flavopiridol, ranging from 20 to 80 mg/m2 in successive cohorts, administered weekly over 1 h. This schedule was repeated for 3 weeks of each 4-week cycle.

RESULTS

Twenty-seven evaluable patients were enrolled. The combination was well tolerated, with one dose-limiting toxicity occurring at flavopiridol 70 mg/m2 (grade 3 mucositis) and one dose-limiting toxicity at 80 mg/m2 (grade 4 neutropenia). We observed 1 complete response in a patient with pancreatic carcinoma and 4 partial responses in pancreatic (1), breast (2), and ovarian (1) cancer patients. Stable disease was seen in 10 patients. Pharmacokinetic studies showed Cmax ranging from 1.49 +/- 0.69 micromol/L (flavopiridol 20 mg/m2) to 4.54 +/- 0.08 micromol/L (flavopiridol 60 mg/m2) in cycle 1.

CONCLUSIONS

Treatment with weekly, sequential docetaxel followed by flavopiridol is an effective and safe regimen at all flavopiridol dose levels. The pharmacokinetic data indicate that concentrations of flavopiridol that enhance the effects of docetaxel both in vitro and in vivo can be achieved. Clinical activity is encouraging, even in patients who have received a prior taxane and in patients with gemcitabine-refractory metastatic pancreatic cancer.

Epothilones in breast cancer: review of clinical experience

BACKGROUND

Drugs that target microtubules, including paclitaxel (Taxol) and docetaxel (Taxotere), are among the most commonly prescribed anticancer therapies. However, the utility of taxane-based therapies is limited by difficulties with formulation, administration, and resistance induced by P-glycoprotein. The epothilones are a novel class of antimicrotubule agents that have demonstrated antitumor activity in the setting of resistance.

DESIGN

This review summarizes clinical studies of epothilones in patients with metastatic breast cancer. Data were identified by searches of PubMed and the Proceedings of the American Society of Clinical Oncology annual meetings from 2000 to 2006.

RESULTS

The epothilones have demonstrated promising antitumor activity and manageable toxicity in phase II studies of heavily pretreated patients with metastatic breast cancer, including patients with resistance to taxanes and other cytotoxic agents. Neuropathy associated with ixabepilone appears to be schedule dependent and comparable to that observed with paclitaxel. Ixabepilone appears to be active in combination with capecitabine.

CONCLUSIONS

Ongoing and planned trials promise to elucidate the benefits of ixabepilone in combination with other agents including capecitabine, bevacizumab, and trastuzumab in patients with metastatic breast cancer as well as those receiving neo-adjuvant therapy.

Long-term Clinical Outcomes of Whole-Breast Irradiation Delivered in the Prone Position

PURPOSE

The aim of this study was to evaluate retrospectively the effectiveness and toxicity of post-lumpectomy whole-breast radiation therapy delivered with prone positioning.

METHODS AND MATERIALS

Between September 1992 and August 2004, 245 women with 248 early-stage invasive or in situ breast cancers were treated using a prone breast board. Photon fields treated the whole breast to 46 to 50.4 Gy with standard fractionation. The target volume was clinically palpable breast tissue; no attempt was made to irradiate chest wall lymphatics. Tumor bed boosts were delivered in 85% of cases. Adjuvant chemotherapy and hormonal therapy were administered to 42% and 62% of patients, respectively.

RESULTS

After a median follow-up of 4.9 years, the 5 year actuarial true local and elsewhere ipsilateral breast tumor recurrence rates were 4.8% and 1.3%, respectively. The 5-year actuarial rates of regional nodal recurrence and distant metastases were 1.6% and 7.4%. Actuarial disease-free, disease-specific, and overall survival rates at 5 years were 89.4%, 97.3%, and 93%, respectively. Treatment breaks were required by 2.4% of patients. Grade 3 acute dermatitis and edema were each limited to 2% of patients. Only 4.9% of patients complained of acute chest wall discomfort. Chronic Grade 2 to 3 skin and subcutaneous tissue toxicities were reported in 4.4% and 13.7% of patients, respectively.

CONCLUSIONS

Prone position breast radiation results in similar long-term disease control with a favorable toxicity profile compared with standard supine tangents. The anatomic advantages of prone positioning may contribute to improving the therapeutic ratio of post-lumpectomy radiation by improving dose homogeneity and minimizing incidental cardiac and lung dose.

Increased dose density is feasible: a pilot study of adjuvant epirubicin and cyclophosphamide followed by paclitaxel, at 10- or 11-day intervals with filgrastim support in women with breast cancer

PURPOSE

Because Cancer and Leukemia Group B 9741 trial showed a benefit for every 14-day administration of chemotherapy compared with every 21-day treatment, we hypothesized that even greater dose density would be more effective. We conducted a pilot trial to assess the feasibility of dose-dense chemotherapy consisting of a standard regime at 10- to 11-day intervals in the adjuvant/neoadjuvant setting. A 2-day window was allowed for scheduling logistics.

EXPERIMENTAL DESIGN

Thirty-nine women with early-stage breast carcinoma were accrued from April 2004 to October 2004. Median age was 47 years (range, 26-67 years). Patients received therapy with 100 mg/m(2) epirubicin and 600 mg/m(2) cyclophosphamide (EC) q 10 to 11 days for four cycles followed by 175 mg/m(2) paclitaxel q 10 to 11 days for four cycles, all with filgrastim support (300 microg s.c. daily) from day 2 to 24 h before the next treatment.

RESULTS

Thirty-five (90%) patients completed all planned therapy. The median intertreatment interval was 10 days (range, 8-28 days). Cycles (80.7%) were delivered at no more than 10- to 11-day intervals. There were five dose reductions of 25% for grade 3 nonhematologic toxicity in five patients. Six (16%) patients developed febrile neutropenia defined as temperature >38 degrees C with absolute neutrophil count <1,000/microL. All febrile neutropenia was during therapy with EC. Other grade 3 toxicities included bone pain, hand and foot syndrome, neuropathy, mucositis, nausea, and vomiting.

CONCLUSIONS

Therapy with EC for four cycles followed by paclitaxel for four cycles at 10- to 11-day intervals is feasible. The approximately 30% reduction in intertreatment interval compared with every 14-day treatment could increase the efficacy of adjuvant chemotherapy.

Incidence of chemotherapy-induced, long-term amenorrhea in patients with breast carcinoma age 40 years and younger after adjuvant anthracycline and taxane

BACKGROUND

Twenty-five percent of all women with breast carcinoma are premenopausal and are at risk for chemotherapy-induced menopause with long-term side effects. Although there is considerable documentation of the rates of chemotherapy-induced amenorrhea with classic adjuvant regimens, there are inadequate data that address the impact of taxanes on menstrual function in this setting. The objective of this analysis was to determine the incidence of long-term amenorrhea (> or = 12 mos) in women with breast carcinoma age 40 years and younger after adjuvant anthracycline and taxane-based chemotherapy, with or without subsequent tamoxifen.

METHODS

The authors identified 235 premenopausal women with breast carcinoma age 40 years or younger who were treated with adjuvant anthracycline and taxane-based chemotherapy at Memorial Sloan-Kettering Cancer Center from January 1997 to June 2003.

RESULTS

One hundred sixty-six patients met all eligibility criteria and had sufficient follow-up for evaluation. The median age of patients at diagnosis was 36 years (range, 27-40 yrs). All patients had regular pretreatment menses, 25 patients (15%) developed long-term amenorrhea, and 141 patients (85%) resumed menstruation. Eighty-two patients (49%) also received tamoxifen: The incidence of amenorrhea among them was 17%. There was a statistically significant association between age and the development of amenorrhea, with older women at higher risk (P < 0.01).

CONCLUSIONS

The sequential addition of a taxane to standard adjuvant anthracycline-based chemotherapy did not appear to produce a high rate of chemotherapy-related amenorrhea compared with historic controls. To increase the information available to assist young patients who are considering adjuvant therapy, prospective studies should incorporate menstrual function ascertainment by patient-reported history and assays of ovarian function.

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.

Risk models for neutropenia in patients with breast cancer

Breast cancer is the most common noncutaneous malignancy in women in industrialized countries. Chemotherapy prolongs survival in patients with early-stage breast cancer, and maintaining the chemotherapy dose intensity is crucial for increasing overall survival. Many patients are, however, treated with less than the standard dose intensity because of neutropenia and its complications. Prophylactic colony-stimulating factor (CSF) reduces the incidence and duration of neutropenia, facilitating the delivery of the planned chemotherapy doses. Targeting CSF to only at-risk patients is cost-effective, and predictive models are being investigated and developed to make it possible for clinicians to identify patients who are at highest risk for neutropenic complications. Both conditional risk factors (e.g., the depth of the first-cycle absolute neutrophil count nadir) and unconditional risk factors (e.g., patient age, treatment regimen, and pretreatment blood cell counts) are predictors of neutropenic complications in early-stage breast cancer. Colony-stimulating factor targeted toward high-risk patients starting in the first cycle of chemotherapy may make it possible for full doses of chemotherapy to be administered, thereby maximizing patient benefit. Recent studies of dose-dense chemotherapy regimens with CSF support in early-stage breast cancer have shown improvements in disease-free and overall survival, with less hematologic toxicity than with conventional therapy. These findings could lead to changes in how early-stage breast cancer is managed.

Current status and future potential role of exemestane in the treatment of early and advanced breast cancer (Review)

Exemestane is a new oral steroidal aromatase inactivator, active in postmenopausal women with hormonal sensitive breast carcinoma. This drug, at a dosage of 25 mg once daily, was shown to suppress in vivo aromatase activity by 97.9%, with a subsequent reduction superior to 85% of circulating oestrogen level. It exhibits definite antitumor activity at a relatively low daily dose, and is highly potent, highly selective, and well-tolerated. Moreover, for postmenopausal women with metastatic breast cancer, exemestane demonstrated a higher activity and lower toxicity profile when compared to megestrol acetate and tamoxifen in second- and first-line therapy, respectively. New data on exemestane are forthcoming both in the adjuvant and neoadjuvant setting, which could improve the management of early breast cancer in the future.

Doxorubicin followed by sequential paclitaxel and cyclophosphamide versus concurrent paclitaxel and cyclophosphamide: 5-year results of a phase II randomized trial of adjuvant dose-dense chemotherapy for women with node-positive breast carcinoma

PURPOSE

We conducted a randomized Phase II trial to directly compare toxicity, feasibility, and delivered dose intensities of two adjuvant dose-intensive regimens containing doxorubicin, paclitaxel, and cyclophosphamide for patients with node-positive breast carcinoma.

EXPERIMENTAL DESIGN

Forty-two patients with resected breast carcinoma involving one or more ipsilateral axillary lymph nodes, were randomized to receive two different schedules of adjuvant chemotherapy using 14-day dosing intervals: either (a) three cycles of doxorubicin 80 mg/m(2) as i.v. bolus followed sequentially by three cycles of paclitaxel 200 mg/m(2) as a 24-h infusion and then by three cycles of cyclophosphamide 3.0 g/m(2) as a 1-h infusion (arm A); or (b) the same schedule of doxorubicin followed by three cycles of concurrent cyclophosphamide and paclitaxel at the same doses (arm B). All cycles were supported by granulocyte colony-stimulating factor administration.

RESULTS

Forty-one patients were assessable for toxicity and feasibility; 37 (90%) completed all planned chemotherapy. There was no treatment-related mortality; however, increased toxicity was observed on arm B compared with arm A, manifested by an increase in hospitalization for toxicity, mainly neutropenic fever, and an increased incidence of transfusion of packed RBCs transfusions for anemia. The mean delivered dose intensities for paclitaxel and cyclophosphamide were significantly greater for arm A compared with arm B (P =.01 and P =.05, respectively). There is no long-term, treatment-related toxicity, and no cases of acute myelogenous leukemia or myelodysplastic syndrome have been observed.

CONCLUSIONS

Dose-dense sequential single-agent chemotherapy is more feasible than doxorubicin with subsequent concurrent paclitaxel and cyclophosphamide.

Weekly trastuzumab and paclitaxel therapy for metastatic breast cancer with analysis of efficacy by HER2 immunophenotype and gene amplification

PURPOSE

This phase II study evaluated weekly trastuzumab and paclitaxel therapy in women with HER2-normal and HER2-overexpressing metastatic breast cancer. Efficacy was correlated with immunohistochemical and fluorescent in situ hybridization (FISH) assay results.

PATIENTS AND METHODS

Eligible patients had bidimensionally measurable metastatic breast cancer. Up to three prior chemotherapy regimens, including prior anthracycline and taxane therapy, were allowed. Trastuzumab 4 mg/kg and paclitaxel 90 mg/m2 were administered on week 1, with trastuzumab 2 mg/kg and paclitaxel 90 mg/m2 administered on subsequent weeks. HER2 status was evaluated using four different immunohistochemical assays and FISH.

RESULTS

Patients received a median of 25 weekly infusions (range, one to 85 infusions). Median delivered paclitaxel dose-intensity was 82 mg/m2/wk (range, 52 to 90 mg/m2/wk). The intent-to-treat response rate for all 95 patients enrolled was 56.8% (95% confidence interval, 47% to 67%). A response rate of 61.4% (4.5% complete response, 56.8% partial response) was observed in 88 fully assessable patients. In patients with HER2-overexpressing tumors, overall response rates ranged from 67% to 81% compared with 41% to 46% in patients with HER2-normal expression (ranges reflect the different assay methods used to assess HER2 status). Differences in response rates between patients with HER2-overexpressing tumors and those with normal HER2 expression were statistically significant for all assay methods, with CB11 and TAB250 antibodies and FISH having the strongest significance. Therapy was generally well tolerated, although three patients had serious cardiac complications.

CONCLUSION

Weekly trastuzumab and paclitaxel therapy is active in women with metastatic breast cancer. Therapy was relatively well tolerated; however, attention to cardiac function is necessary.