A phase II study of pembrolizumab plus carboplatin in BRCA-related metastatic breast cancer (PEMBRACA)

BACKGROUND

BRCA1/2-related metastatic breast cancers (mBC) are sensitive to DNA-damage agents and show high tumor-infiltrated lymphocytes. We hypothesized that the association between pembrolizumab and carboplatin could be active in BRCA-related mBC.

PATIENTS AND METHODS

In this phase II Simon's design multicenter single-arm study, BRCA1/2-related mBC patients received carboplatin at area under the curve 6 every 3 weeks for six courses associated with 200 mg pembrolizumab every 3 weeks until disease progression or unacceptable toxicity. The primary aim at first stage was overall response rate (ORR) ≥70%. Disease control rate (DCR), time to progression (TTP), duration of response (DOR), and overall survival (OS) were the secondary aims.

RESULTS

Among 22 patients enrolled at the first stage, 5 BRCA1 and 17 BRCA2, 16 (76%) were luminal tumors and 6 (24%) triple-negative BC (TNBC). In 21 patients, ORR and DCR were 43% and 76% (47% and 87% in luminal, 33% and 50% in TNBC), respectively. TTP was 7.1 months, DOR was 6.3 months, and median OS was not reached. Grade ≥3 adverse events (AEs) or serious AEs occurred in 5/22 patients (22.7%). Since the primary aim was not met, the study was terminated at the first stage.

CONCLUSIONS

Although the primary aim was not reached, data on efficacy and safety of pembrolizumab plus carboplatin in first-line visceral disease BRCA-related luminal mBC were provided and they need to be further investigated.

De-escalated therapy for HR+/HER2+ breast cancer patients with Ki67 response after 2-week letrozole: results of the PerELISA neoadjuvant study

BACKGROUND

In human epidermal growth factor receptor 2 (HER2+) breast cancers, neoadjuvant trials of chemotherapy plus anti-HER2 treatment consistently showed lower pathologic complete response (pCR) rates in hormone receptor (HR) positive versus negative tumors. The PerELISA study was aimed to evaluate the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HR+/HER2+ breast cancer patients selected on the basis of Ki67 inhibition after 2-week letrozole.

PATIENTS AND METHODS

PerELISA is a phase II, multicentric study for postmenopausal patients with HR+/HER2+ operable breast cancer. Patients received 2-week letrozole, and then underwent re-biopsy for Ki67 evaluation. Patients classified as molecular responders (Ki67 relative reduction >20% from baseline) continued letrozole and started trastuzumab-pertuzumab for five cycles. Patients classified as molecular non-responders started weekly paclitaxel for 13 weeks combined with trastuzumab-pertuzumab. Primary aim was breast and axillary pCR. According to a two-stage Simon's design, to reject the null hypothesis, at least 8/43 pCR had to be documented.

RESULTS

Sixty-four patients were enrolled, 44 were classified as molecular responders. All these patients completed the assigned treatment with letrozole-trastuzumab-pertuzumab and underwent surgery. A pCR was observed in 9/44 cases (20.5%, 95% confidence interval 11.1% to 34.5%). Among molecular non-responders, 16/17 completed treatment and underwent surgery, with pCR observed in 81.3% of the cases. PAM50 intrinsic subtype was significantly associated with Ki67 response and pCR. Among molecular responders, the pCR rate was significantly higher in HER2-enriched than in other subtypes (45.5% versus 13.8%, P = 0.042).

CONCLUSIONS

The primary end point of the study was met, by reaching the pre-specified pCRs. In patients selected using Ki67 reduction after short-term letrozole exposure, a meaningful pCR rate can be achieved without chemotherapy. PAM50 intrinsic subtyping further refines our ability to identify a subset of patients for whom chemotherapy might be spared.

EUDRACT NUMBER

2013-002662-40.

CLINICALTRIALS.GOV IDENTIFIER

NCT02411344.

Association of tumor-infiltrating lymphocytes with distant disease-free survival in the ShortHER randomized adjuvant trial for patients with early HER2+ breast cancer

BACKGROUND

There is the need to identify new prognostic markers to refine risk stratification for HER2-positive early breast cancer patients. The aim of this study was to evaluate the association of tumor-infiltrating lymphocytes (TILs) with distant disease-free survival (DDFS) in patients with HER2-positive early breast cancer enrolled in the ShortHER adjuvant trial which compared 9 weeks versus 1-year trastuzumab in addition to chemotherapy, and to test the interaction between TILs and treatment arm.

PATIENTS AND METHODS

Stromal TILs were assessed for 866 cases on centralized hematoxylin and eosin-stained tumor slides. The association of TILs as 10% increments with DDFS was assessed with Cox models. Kaplan-Meier curves were estimated for patients with TILs ≥20% and TILs <20%. Median follow-up was 6.1 years.

RESULTS

Median TILs was 5% (Q1-Q3 1%-15%). Increased TILs were independently associated with better DDFS in multivariable model [hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.59-0.89, P = 0.006, for each 10% TILs increment]. Five years DDFS rates were 91.1% for patients with TILs <20% and 95.7% for patients with TILs ≥20% (P = 0.025). The association between 10% TILs increments and DDFS was significant for patients randomized to 9 weeks of trastuzumab (HR 0.60, 95% CI 0.41-0.88) but not for patients treated with 1 year of trastuzumab (HR 0.89, 95% CI 0.71-1.12; test for interaction P = 0.088). For patients with TILs <20%, the HR for the comparison between the short versus the long arm was 1.75 (95% CI 1.09-2.80, P=0.021); whereas, for patients with TILs ≥20% the HR for the comparison of short versus long arm was 0.23 (95% CI 0.05-1.09, P = 0.064), resulting in a significant interaction (P = 0.015).

CONCLUSIONS

TILs are an independent prognostic factor for HER2-positive early breast cancer patients treated with adjuvant chemotherapy and trastuzumab and may refine the ability to identify patients at low risk of relapse eligible for de-escalated adjuvant therapy.

Nine weeks versus 1 year adjuvant trastuzumab in combination with chemotherapy: final results of the phase III randomized Short-HER study‡

Background

Chemotherapy plus 1-year trastuzumab is the standard adjuvant treatment of HER2-positive breast cancer. The efficacy of less extended trastuzumab exposure is under investigation. The short-HER study was aimed to assess the non-inferiority of 9 weeks versus 1 year of adjuvant trastuzumab combined with chemotherapy.

Patients and methods

HER2-positive breast cancer patients with node-positive or, if node negative, with at least one risk factor (pT>2 cm, G3, lympho-vascular invasion, Ki-67 > 20%, age ≤35 years, or hormone receptor negativity) were randomly assigned to receive sequential anthracycline-taxane combinations plus 1-year trastuzumab (arm A, long) or plus 9 weeks trastuzumab (arm B, short). This study was designed as a non-inferiority trial with disease-free survival (DFS) as primary end point. A DFS hazard ratio (HR) <1.29 was chosen as the non-inferiority margin. Analyses according to the frequentist and Bayesian approach were planned. Secondary end points included 2-year failure rate and cardiac safety.

Results

A total of 1254 patients from 82 centers were randomized (arm A, long: n = 627; arm B, short: n = 626). Five-year DFS is 88% in the long and 85% in the short arm. The HR is 1.13 (90% CI 0.89-1.42), with the upper limit of the CI crossing the non-inferiority margin. According to the Bayesian analysis, the probability that the short arm is non-inferior to the long one is 80%. The 5-year overall survival (OS) is 95.2% in the long and 95.0% in the short arm (HR 1.07, 90% CI 0.74-1.56). Cardiac events are significantly lower in the short arm (risk-ratio 0.33, 95% CI 0.22-0.50, P < 0.0001).

Conclusions

This study failed to show the non-inferiority of a shorter trastuzumab administration. One-year trastuzumab remains the standard. However, a 9-week administration decreases the risk of severe cardiac toxicity and can be an option for patients with cardiac events during treatment and for those with a low risk of relapse.

Trial Registration

EUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Abstract P3-10-24: Not presented

This abstract was not presented at the conference.

Citation Format: Gasparini E, Bisagni A, Di Cicilia R, Kuhn E, Falco G, Ferrari G, Foroni M, Tamagnini I, Bassano C, Ragazzi M, Gardini G, Cecchi F, Hembrough T, Bisagni G. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-24.

Abstract P6-17-05: Independent validation of a combined biomarker based on the PAM50 HER2-enriched subtype and ERBB2 mRNA levels following HER2 blockade without chemotherapy in the PerELISA phase II trial

Background: A combined biomarker based on HER2-enriched subtype (HER2-E) and ERBB2 mRNA predicts response and survival in HER2+ breast cancer following trastuzumab +/- lapatinib in the absence of chemotherapy (Prat et al. ASCO 2018). Here, we tested the ability of the combined biomarker to predict pathological complete response (pCR) following neoadjuvant trastuzumab, pertuzumab and endocrine therapy.

Methods: RNA from 40 baseline tumor samples from the phase II PerELISA trial were evaluated. PerELISA evaluated the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen based on dual HER2 blockade with trastuzumab and pertuzumab in combination with letrozole in HER2+/hormone receptor-positive breast cancer selected on the basis of Ki67 response after short course letrozole-alone (Guarneri ASCO 2018). Ki67 response was defined by protocol as relative Ki67 reduction ≥20% from baseline at day 14. Gene-expression was measured using the nCounter platform. Intrinsic subtypes and ERBB2 levels were determined by the PAM50 gene expression predictor. A pre-specified ERBB2 cutoff was determined to define ERBB2-high. Univariate and multivariable logistic regression analyses were performed.

Results: The proportion of HER2-E disease within the ERBB2-high and ERBB2-low groups was 46.2% (6/13) and 18.5% (5/27), respectively. The discordance rate at the individual level was 30% (12/40). A total of 6 (15%) and 34 (85%) samples were HER2-E/ERBB2-high and others, respectively. The magnitude of Ki67 reduction of the HER2-E/ERBB2-high and others groups was 64.8% and 63.2%, respectively (p=0.88). The pCR rate of HER2-E/ERBB2-high was 66.7%. The pCR rate of the others group was 14.7%. The univariate odds ratio between HER2-E/ERBB2-high tumors and the others groups was 11.60 (95% CI 1.66-81.10; p=0.014). No other clinical-pathological variable was significantly associated with pCR.

Conclusion: The combined HER2-E/ERBB2-high biomarker can identify patients who might be good candidates to receive dual HER2 blockade alone without chemotherapy.

Citation Format: Prat A, Griguolo G, Dieci MV, Bisagni G, Frassoldati A, Bianchi GV, Pascual T, Pare L, Galvan P, Urso L, Conte P, Guarneri V. Independent validation of a combined biomarker based on the PAM50 HER2-enriched subtype and ERBB2 mRNA levels following HER2 blockade without chemotherapy in the PerELISA phase II trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-05.

Bone Marrow Biopsy in the Staging of Small Cell Lung Cancer

From April 1982 to December 1987, 71 patients with small cell lung cancer entered a randomized clinical trial, and underwent bone marrow biopsy (BMB) as part of staging procedures. We identified 8 patients (11 %) with bone marrow metastases, 6 with extensive disease independently of BMB, and 2 with extensive disease on the basis of the BMB only. BMB determined a change in the stage in only 3 % (2/71) of the cases. No differences were found in the hematological parameters of the patients with or without bone marrow metastases. The median survival of the patients with bone marrow involvement was the same (41 weeks) as those with extensive disease but without bone marrow involvement. We conclude that unilateral BMB without aspiration detects a substantial proportion of bone marrow metastases in patients with extensive disease. This fact does not worsen the prognosis. A small proportion of patients with apparently limited disease has bone marrow involvement. The technique therefore contributes, to a small extent, to the definition of the clinical stage of the disease. However, bone marrow involvement is an important data of natural history, and therefore new methods to better assess this peculiar site of the disease are needed.

Cisplatin and VP16 in Metastatic Breast Carcinoma as a Third-Line Chemotherapy: A Randomized Study Comparing Low versus High Doses of Cisplatin

Aims and background

The study was designed to define the activity of the combination of cisplatin and etoposide as third-line chemotherapy for advanced breast cancer and to investigate the role of the dosage of cisplatin on the effectiveness of the combination.

Methods

Ninety-five eligible patients with advanced breast cancer who had failed or relapsed on two previous lines of chemotherapy were randomized to receive cisplatin at a high dose (100 mg/m2 i.v. day 1, arm A) or a low dose (60 mg/m2 day 1, arm B), combined with etoposide (100 mg/m2 i.v. days 4, 6 and 8). Cycles were repeated every 3 weeks.

Results

Of the 78 patients evaluable for response (39 in arm A and 39 in arm B), 9 (12%) showed complete or partial response, 5 (13%) in the high-dose arm and 4 (10%) in the low-dose arm. One complete response was seen in the high-dose arm and none in the low-dose arm. The only 2 patients with brain involvement showed an objective response (one CR in arm A and one PR in arm B). Median time to progression was 14 weeks in arm A and 10 weeks in arm B, median duration of remission 28 and 34 weeks, and survival 36 and 35 weeks, respectively. The differences were not significant. As expected, the patients in the high-dose arm experienced more severe toxicity. One toxic death was observed in each arm due to sepsis in agranulocytosis. The difference was statistically significant regarding nausea and vomiting. Neurotoxicity and ototoxicity were not relevant problems in this patient setting.

Conclusions

Considering the very poor prognostic factors presented by these patients, the combination showed a certain activity, and further evaluation in earlier stages of disease is warranted. A particular responsiveness on brain metastases is suggested. The dose of cisplatin was not proven to be of significant importance.

Neoadjuvant Chemotherapy with Continuous Infusion of Cisplatin and Fluorouracil in Stage II-IV, M0 Squamous Cell Carcinoma of the Head and Neck

Aims and Background

The aim of the study was to assess the activity and the toxicity of cisplatin (DDP) and fluorouracil (FU) administered by continuous infusion as neoadjuvant chemotherapy for patients with stage II-IV, MO squamous cell carcinoma of the head and neck.

Methods

Thirty previously untreated patients were submitted to chemotherapy with DDP (20 mg/m2) and FU (1000 mg/m2), both in continuous infusion for 5 days, repeated every 21 days, for a maximum of 5 cycles. Following completion of chemotherapy, the patients underwent radiotherapy; in some patients surgery was performed immediately after chemotherapy. All patients were monitored for response, time to failure, survival, treatment-related events and toxicity.

Results

All patients were evaluated for response; after chemotherapy the complete response rate was 27% and the partial response rate 33%. Twenty-four patients underwent radiotherapy: the overall response rate was 83% (complete response 79%). After a median follow-up of 34 months, the median survival time was 22 months with a median time to failure of 15 months. Acute vascular accidents were the main and unexpected adverse events, with 2 deaths for pulmonary embolism and 1 for stroke. The response rate to the regimen does not seem to be better than that obtained with the standard combination of cisplatin bolus and fluorouracil continuous infusion. The disadvantage of the regimen is that it causes more discomfort for the patient in that it requires hospitalization.

Conclusions

For this reason, we believe that there are no elements for recommending the schedule as neoadjuvant treatment of patients with squamous cell carcinoma of the head and neck or as an experimental arm in a randomized trial.

Soft Tissues Sarcoma with Acute Paraneoplastic Hepatic Dysfunction: Case Report

A case of malignant fibrous histiocytoma of soft tissues of the right scapula associated with transitory hepatic dysfunction in the absence of liver metastases is reported. After primary radiation therapy, the patient manifested fever, anemia, thrombocytosis and hepatic dysfunction. All the abnormalities disappeared immediately after complete removal of the tumor. The patient was well, with no evidence of distant metastases, at more than 12 months later. It is concluded that the abnormalities of laboratory data were indirectly induced by the tumor, although the exact mechanism of this paraneoplastic syndrome was not clarified.

Lonidamine in Advanced Colorectal Cancer: A Phase II Study of the Italian Oncology Group for Clinical Research (Goirc)

Twenty-one patients with metastatic colorectal adenocarcinoma, all previously treated with chemotherapy for metastatic disease, were treated with lonidamine (LDN). The major toxicity encountered was muscular (myalgias in 48%) and gastrointestinal (nausea and/or vomiting in 52%). Other toxicities included abdominal pain, somnolence, fever, arthralgia and ototoxicity. In the 14 patients evaluable for response we observed no complete or partial remission, 8 stable disease and 6 progressive disease. LND has no clinically worthwhile activity against colorectal carcinoma refractory to conventional chemotherapy.

Aminoglutethimide in Advanced Breast Cancer

From July 1980 to June 1983, 61 postmenopausal women with progressive metastatic breast cancer were treated with aminoglutethimide, 250 mg 4 times daily, plus cortisone acetate, 25 mg twice daily. Of 51 evaluable patients, an objective remission was observed in 22 (43 %) (partial remission in 19, complete in 3), stable disease in 14 (27 %), and progressive disease in 15 (30 %). The median duration of response was 60 weeks (range 12 +; 94+). The response rate was higher when the dominant disease site was soft tissue (50 %) or bone (56 %) rather than viscera (29 %). Side effects were common but usually slight and transient. Somnolence (69 %), dizziness (41 %), nausea (35 %) and skin rash (27 %) were the most frequent. Serum levels of gamma-GT, alkaline phosphatase and total cholesterol rose during aminoglutethimide treatment, whereas levels of uric acid and indirect bilirubin decreased. Aminoglutethimide plus cortisone acetate appears to be an active and relatively safe treatment in advanced breast cancer and may be recommended as second-line endocrine treatment.

Ifosfamide Bolus Followed by Five Days Continuous Infusion in Extensively Pretreated Patients with Advanced Breast Cancer: A Phase II Study

PURPOSE

A phase II study with ifosfamide in pretreated patients with advanced breast cancer was performed to determine the objective response rate, the toxicity and the feasibility of the regimen.

METHODS & STUDY DESIGN

Patients enrolled had advanced breast cancer pretreated with at least one previous regimen of chemotherapy for advanced disease. Treatment consisted of ifosfamide infused at a dose of 2 g/m2 iv in 4 hrs followed by ifosfamide, 8 g/m2 iv in 120 hrs in ambulatory treatment, using a portable external pump system. The total dose of ifosfamide was 10 g/m2; mesna (4 g/m2 iv) was administered mixed with ifosfamide in 120 hrs Cycles were repeated every 3 weeks. Three patients were pretreated with neoadjuvant and 15 with adjuvant chemotherapy. All patients were treated for advanced disease (median number of regimens, 1; range, 1-3): 21 with the cyclophosphamide-containing regimen and 15 with adryamicin. Sixteen patients received one or more lines of endocrine therapy. Fifteen patients had dominant site in viscera, 6 in bone, and only one in soft tissue; 17 patients had more than one site of disease.

RESULTS

Twenty-two patients were enrolled and all were assessable for response and toxicity. A partial response was reached in 5 patients (23%; 95% confidence limits 5% to 60%). Hematologic toxicity was the dose-limiting side effect; grade 4 leukopenia occurred in 10 patients (46%).

CONCLUSIONS

Considering the response rate obtained in our series of intensively pretreated patients, the results seem to indicate that the regimen is active and could be included among the possible options in the treatment of patients with refractory, poor-prognosis, advanced breast carcinoma.

Abstract OT1-03-03: Phase II, open label, randomized, biomarker study of immune-mediated mechanism of action of neoadjuvant subcutaneous trastuzumab in patients with operable or locally advanced/Inflammatory HER2-positive breast cancer. ImmunHER trial on behalf of the Gruppo Oncologico Italiano di Ricerca Clinica (GOIRC)

Background: Tumor-infiltrating lymphocytes (TILs) have been reported to be associated with increased therapeutic efficacy of trastuzumab in the (neo)adjuvant setting for HER2-positive breast cancer (BC). Subcutaneous (SC) trastuzumab has been observed to act at different immunologic levels than IV trastuzumab. Therefore, by modifying the modality of administration of trastuzumab, it could be possible to interfere with different pathways of the immune system and exert a favorable immunomodulation in HER2-positive BC.

Trial design: In this non-comparative, phase II, neoadjuvant, randomized study, patients will be treated with FEC chemotherapy (fluorouracil 500 mg/m2; epirubicin 75 mg/m2; cyclophosphamide 500 mg/m2) q21 for 3 cycles. Then, they will be randomly assigned in a 1:1 ratio to receive: docetaxel (75 mg/m2) plus pertuzumab (840 mg loading dose, then 420 mg) plus IV trastuzumab (8 mg/kg loading dose, then 6 mg/kg) q21 for 4 cycles (Group A) or, docetaxel plus pertuzumab plus SC trastuzumab (fixed dose of 600 mg) q21 for 4 cycles (Group B). After surgery, study patients will receive trastuzumab q21 x 14 cycles using the same formulation (SC or IV) of the preoperative phase.

Eligibility criteria: Patients must have previously untreated, T2-4d primary HER2-positive BC with no metastatic disease. Other inclusion criteria are: age 18 or older; ECOG performance status 0-1; availability of tumor tissue from diagnostic biopsy; normal left ventricular ejection fraction; normal organ and marrow function.

Specific aims: The main objective of this trial is to evaluate variations of host immune response parameters to either trastuzumab SC or trastuzumab IV given in combination with pertuzumab and chemotherapy as neoadjuvant treatment of patients with HER2-positive BC. Tumor samples obtained at diagnosis and at definitive surgery will be centrally analyzed for TILs. Blood samples will be also collected during study treatment for tumor-specific lymphocyte cell activity (TLA) analysis. Feasibility, efficacy, safety and health-related quality of life will be also evaluated.

Statistical methods: The primary endpoint is post-surgery pathologic TIL rate on residual disease. The threshold for classifying subjects with high TILs, or not, is defined as equal to 15%, according to the median TIL rate observed in primary HER2-positive tumors. Because this is a phase II study with 2 non-comparative arms, Simon's optimal 2-stage design will be used for each of the 2 study groups. For each arm we assume: p1 = 0.4, expected rate of subjects with high TILs on residual disease, p0 = 0.1, lowest limit of the subject rate (alpha= 0.05; beta= 0.20).

Present accrual and target accrual: A total of 60 patients (first stage: 16 patients) will be enrolled from multiple institutions. From November 29, 2016 to June 11, 2017, 34 patients have been recruited.

Contact information:Dr. Antonino Musolino, MD, MSc, PhD; Medical Oncology Unit, University Hospital of Parma; Tel: +390521702316; Fax: +390521995448; e-mail: amusolino@ao.pr.it. Clinical Trials.gov: NCT03144947.

Citation Format: Musolino A, Gori S, Cavanna L, Graiff C, Frassoldati A, Bria E, Bisagni G, Zambelli A, Partesotti G, Brandes A, Bonetti A, Moscetti L, Zamagni C, Rocca A, Generali D, Montemurro F, Gianni L, Tognetto M, Maglietta G, Todeschini R. Phase II, open label, randomized, biomarker study of immune-mediated mechanism of action of neoadjuvant subcutaneous trastuzumab in patients with operable or locally advanced/Inflammatory HER2-positive breast cancer. ImmunHER trial on behalf of the Gruppo Oncologico Italiano di Ricerca Clinica (GOIRC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-03-03.

Abstract P1-13-02: Withdrawn

This abstract was withdrawn by the authors.

Prognostic impact of interval breast cancer detection in women with pT1a N0M0 breast cancer with HER2-positive status: Results from a multicentre population-based cancer registry study

BACKGROUND

Although human epidermal growth factor receptor 2 (HER2) overexpression is associated with poor prognosis, patients (pts) with pT1a N0M0 breast cancers (BCs) have an excellent outcome across all subtypes. Interval cancers (ICs) have poorer survival than screen-detected (SD) tumours, and an association has been reported between ICs and HER2 overexpression. We aimed to determine, in a general population of pT1a N0M0 BCs with known screening status, whether HER2-positive ICs have a poorer outcome than HER2-positive SD cancers.

METHODS

We evaluated all incident pT1a N0M0 BCs (n = 874) collected in the Emilia-Romagna region (Italy) from 2003 to 2009 and diagnosed in women aged 50-69. Pts unexposed to screening, with unknown HER2 status and/or treated with adjuvant trastuzumab were excluded from analysis.

RESULTS

Sixty-one percent of the BCs were SD, whereas 19% were ICs. BCs with high histologic grade, hormone receptor-negative or HER2-positive status (odds ratio=1.7; 95% confidence interval [CI]: 1.1-2.7) were more likely ICs. Median follow-up was 115 months. The 10-year invasive disease-free survival (iDFS) for HER2-positive ICs was lower than that for HER2-positive SD cancers: 75.0% (95% CI: 55.5%-94.5%) versus 93.8% (95% CI: 86.5%-100%). An interaction between ICs and HER2-positive status was found for poorer iDFS after adjusting for prognostic variables (HR = 5.3; 95% CI: 1.6-16.7).

CONCLUSIONS

IC detection may identify pts with HER2-positive pT1a N0M0 tumours in whom the rate of recurrence justifies consideration for conventional, anti-HER2, adjuvant treatment.

Tumor-infiltrating lymphocytes and molecular response after neoadjuvant therapy for HR+/HER2- breast cancer: results from two prospective trials

PURPOSE

The aim was to evaluate the role of tumor-infiltrating lymphocytes (TIL) in predicting molecular response after preoperative endocrine or cytotoxic treatment for HR+/HER2- patients who do not achieve a pathological complete response.

METHODS

Stromal (Str) TIL were centrally evaluated on samples from diagnostic core-biopsies of HR+/HER2- patients included in two prospective randomized trials: the LETLOB trial (neoadjuvant endocrine-based treatment) and the GIOB trial (neoadjuvant chemotherapy-based treatment). Pre- and post-treatment Ki67 was centrally assessed.

RESULTS

StrTIL were evaluable in 111 cases (n = 73 from the LETLOB trial and n = 38 from the GIOB trial). Median StrTIL was 2%. Patients with high StrTIL (StrTIL ≥10%, n = 28) had more frequently breast cancer of ductal histology (p = 0.02), high grade (p = 0.049), and high Ki67 (p = 0.02). After neoadjuvant endocrine treatment (LETLOB cohort), a significant Ki67 suppression (p < 0.01) from pre- to post-treatment was observed in both the low and high StrTIL groups. High StrTIL patients achieve more frequently a relative Ki67 suppression ≥50% from baseline as compared to low StrTIL patients (55 vs. 35%, p non significant). After neoadjuvant chemotherapy (GIOB cohort), a significant Ki67 suppression was observed only for low StrTIL patients (Wilcoxon p = 0.001) and not in the high StrTIL group (p = 0.612). In this cohort, the rate of patients achieving a relative Ki67 suppression ≥50% from baseline was significantly higher in the low vs high StrTIL group (64% vs 10%, p = 0.003). Geometric mean Ki67 suppression was evaluated in each cohort according to StrTIL: the lowest value (-41%) was observed for high StrTIL cases treated with chemotherapy.

CONCLUSIONS

This hypothesis-generating study suggests that in HR+/HER2- breast cancer StrTIL at baseline may influence the achievement of a molecular response after neoadjuvant treatment. Further evaluation in large studies is needed, and interaction with the type of treatment warrants to be explored.

Abstract P1-09-12: Dose dense adjuvant chemotherapy in patients with early breast cancer: Differential treatment effects according to composite index of benefit

Background In patients with node-positive early breast cancer (EBC), dose-dense adjuvant chemotherapy improves disease-free survival (DFS) compared with standard interval chemotherapy. The GIM2 trial supports the value of dose-dense chemotherapy and suggests that the benefit is present in patients with hormone receptor-negative or hormone receptor-positive tumours (Del Mastro et al. Lancet 2015). In order to individualize decision making, there is a need to examine the absolute treatment effects of dose dense chemotherapy according to patient and tumor characteristics.

Patients and Methods The randomized phase III GIM2 trial enrolled 2091 patients. The primary endpoint was DFS. A continuous, composite measure of treatment benefit for each patient was determined from a Cox model incorporating potential predictive factors (age: 25-40/41-55/56-71; histological grade: 1+2/3; hormonal receptor status: positive/negative). Subpopulation treatment effect pattern plot methodology was used to reveal differential treatment effects on DFS according to composite index. The study focused on patients with HER2–negative disease (N=1287).

Results On average, the magnitude of benefit with dose dense chemotherapy versus standard chemotherapy ranged widely across different subpopulations, as quantified by the composite measure of relevant variables. The highest benefit was observed in patients with high grade, hormone receptor-negative disease (hazard ratio for DFS 0.44, 95% CI 0.23-0.83). Of note, a relevant benefit was observed also in patients with high grade, hormone receptor-positive disease (hazard ratio for DFS 0.74, 95% CI 0.50-1.09).

Conclusion The absolute improvement in DFS with dose dense adjuvant chemotherapy is substantial in some patients with node-positive HER2-negative breast cancer, particularly those regarded as having high index risk (hormone receptor-negative, high grade disease). Interestingly, a significant effect of dose dense chemotherapy was observed also in patients with hormone receptor-positive, high grade disease.

Citation Format: Puglisi F, Ceppi M, Cognetti F, De Placido S, Bruzzi P, De Laurentiis M, Bisagni G, Cavazzini G, Durando A, Turletti A, Valle E, Montemurro F, Barni S, Ardizzoni A, Gamucci T, Colantuoni G, Del Mastro L. Dose dense adjuvant chemotherapy in patients with early breast cancer: Differential treatment effects according to composite index of benefit [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 P1-09-12.

Immunoglobulin G fragment C receptor polymorphisms and efficacy of preoperative chemotherapy plus trastuzumab and lapatinib in HER2-positive breast cancer

Lapatinib enhances antibody-dependent cell-mediated cytotoxicity (ADCC) activity of trastuzumab. FcγR polymorphisms have been associated with both ADCC and clinical activity of trastuzumab in HER2+ breast cancer (BC) patients (pts). We analyzed FcγRIIa-H131R and FcγRIIIa-V158F polymorphisms in the CHER-LOB trial population of HER2+ BCs treated with preoperative chemotherapy plus trastuzumab (arm A), lapatinib (arm B) or both (arm C). Genotyping was successfully performed in 73/121 (60%) pts. A significant improvement in pathological complete response (pCR) rate was observed for the combination arm C, but only in FcγRIIIa V allele carriers (C vs A, 67 vs 27%, P=0.043; C vs B, 67 vs 22%, P=0.012). An independent interaction between arm C and FcγRIIIa V allele was found for pCR (odds ratio=9.4; 95% confidence interval, 2.3-39.6; P=0.003). No significant associations were observed between pCR and FcγRIIa polymorphism, and between pre-treatment tumor-infiltrating lymphocytes and FcγR polymorphisms. Our study provides evidence for a FcγRIIIa V allele-restricted pCR benefit from neoadjuvant trastuzumab plus lapatinib in HER2+ BC.

Body mass index and circulating oestrone sulphate in women treated with adjuvant letrozole

BACKGROUND

Obesity is an independent adverse prognostic factor in early breast cancer patients, but it is still controversial whether obesity may affect adjuvant endocrine therapy efficacy. The aim of our study (ancillary to the two clinical trials Gruppo Italiano Mammella (GIM)4 and GIM5) was to investigate whether the circulating oestrogen levels during treatment with the aromatase inhibitor letrozole are related to body mass index (BMI) in postmenopausal women with breast cancer.

METHODS

Plasma concentration of oestrone sulphate (ES) was evaluated by radioimmunoassay in 370 patients. Plasma samples were obtained after at least 6 weeks of letrozole therapy (steady-state time). Patients were divided into four groups according to BMI. Differences among the geometric means (by ANOVA and ANCOVA) and correlation (by Spearman's rho) between the ES levels and BMI were assessed.

RESULTS

Picomolar geometric mean values (95% confidence interval, n=patients) of circulating ES during letrozole were 58.6 (51.0-67.2, n=150) when BMI was <25.0 kg m(-2); 65.6 (57.8-74.6, n=154) when 25.0-29.9 kg m(-2); 59.3 (47.1-74.6, n=50) when 30.0-34.9 kg m(-2); and 43.3 (23.0-81.7, n=16) when ≥35.0 kg m(-2). No statistically significant difference in terms of ES levels among groups and no correlation with BMI were observed.

CONCLUSIONS

Body mass index does not seem to affect circulating oestrogen levels in letrozole-treated patients.

Abstract P4-14-03: Preoperative carboplatin-paclitaxel-bevacizumab in triple negative breast cancer: Final results of the phase II CA.Pa.Be study

Introduction: Management of triple negative breast cancer (TNBC) is still a major challenge: a significant proportion patients relapse despite adjuvant chemotherapy, and the median survival from relapse rarely exceeds 1 year. Angiogenesis activation as well as impairment in mechanisms of DNA repair are frequently described in sporadic TNBCs, but the role of angiogenesis inhibitors and platinum salts is still controversial. This is a phase II trial of preoperative carboplatin-paclitaxel in combination with bevacizumab in TNBC patients with previously untreated, stage II-III disease. The primary aim of the study is the pathologic complete response (pCR) rate. Among the secondary aims: safety, breast conserving surgery rate, early response assessment with dynamic contrast-enhanced Magnetic Resonance Imaging (DCE-MRI), biomarker analyses.

Methods: Patients with hormone receptor negative (ER and PgR &lt;1%), HER2 negative stage II-III breast cancer are eligible. At baseline, patients undergo breast DCE-MRI, followed by a single dose of bevacizumab 5 mg/kg (day -7). DCE-MRI is repeated prior to start chemotherapy (CT). On day 1, patients start CT with paclitaxel 80 mg/sqm+carboplatin AUC2 on days 1,8, 15 q 28, combined with bevacizumab 10 mg/kg on days 1 and 15. Patients received 5 preoperative cycles and undergo surgery within 6 weeks from the last CT course. Bevacizumab is omitted on cycle 5, to minimize the risk of surgical complications. Tissue samples are centralized to evaluate treatment effect on several tissue markers, as well as to identify potential predictors of treatment benefit. The sample size is estimated with the two-stage Simon's design, on the basis of a 40% expected pCR rate. A total of 43 patients are required, with the combination deemed worthwhile in case of at least 13 pCRs.

Results: the accrual of the 44 planned patients is completed. Patients characteristics were as follows:

median age 46 yrs (29-74); clinical stage IIA: 38.2%, IIB: 35.3%, III: 26.5%; ductal histology: 89%; histologic grade 3: 95%. Notably, 59% of the patients had clinically involved axillary nodes. At present, 33 patients are assessable for toxicity. Bevacizumab-associated adverse events (AEs) were mild: grade 1-2 hypertension occurred in 3 patients (9%) and grade 1 bleeding in 9 patients (27%). No grade 4 non-hematologic AEs were recorded; Grade 3 AEs were: liver function tests abnormalities in 3 patients, diarrhea in 3 patients, and neuropathy in 1 patient. Thirty-one patients underwent surgery, 16 patients (51%) received breast conserving surgery. A pCR in breast and axillary lymph-nodes was achieved in 16 patients (51%); 25 patients (81%) had negative axillary nodes (yN0).

Conclusions: No unexpected toxicity was observed by combining bevacizumab to neoadjuvant platinum-taxane based CT. This combination is active in TNBCs, and the rate of pCR is in the expected range. Moreover, 80% of the patients have nodal negativity at surgery, and these results are of particular interest taking into account the high proportion of patients with clinically involved nodes at the time of diagnosis. The final results along with biomarkers data and early response assessment with DCE-MRI will be available at the time of the meeting.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-14-03.