Multidisciplinary clinical guidelines in proactive monitoring, early diagnosis, and effective management of trastuzumab deruxtecan (T-DXd)-induced interstitial lung disease (ILD) in breast cancer patients

Trastuzumab deruxtecan (T-DXd), a human epidermal growth factor receptor 2 (HER2)-directed antibody-drug conjugate (ADC), has altered the treatment landscape in breast cancer (BC), irrespective of the HR-receptor status. The use of the agent is increasing, despite the finding that exposure to T-DXd increases the risk of interstitial lung disease (ILD), particularly in BC patients. Although T-DXd-related ILD can be potentially severe and life-threatening, most low-grade cases can be treated safely using a multidisciplinary approach comprising early and accurate diagnosis, effective management, close monitoring, and the prompt administration of steroids. Additionally, increasing patients' education on ILD symptoms ensures close attention and enables prompt reporting, enhancing patient outcomes. It is recommended that predictive biomarkers are assessed in patients with risk factors for developing ILD. Currently, diagnostic criteria comprise newly identified pulmonary opacities, the relation of symptom onset to medication initiation, and the exclusion of other causes of ILD. The general condition of patients is weakened during the management of ILD (BC progression and corticosteroid treatment). Consequently, BC chemotherapy might be attenuated. This highlights the importance of preventing (high-grade) ILD, especially since its use is expanded. Identifying high-risk patients, diagnosing, and customizing treatment is, however, challenging and additional information on patient selection is often not fully clarified. In this paper, we provide updated multidisciplinary clinical guidance for patient selection, proactive monitoring, early diagnosis, and effectively management of T-DXd-induced ILD in HER2-positive BC patients. We describe the risk factors for developing ILD, patients' characteristics of ILD, and the histopathological and radiographic characteristics of ILD, including real-world clinical practice reports. These recommendations provide a structured step-by-step approach for managing each suspected BC-related ILD grade.

Final results of the real-life observational VICTOR-6 study on metronomic chemotherapy in elderly metastatic breast cancer (MBC) patients

Nowadays, treatment of metastatic breast cancer (MBC) has been enriched with novel therapeutical strategies. Metronomic chemotherapy (mCHT) is a continuous and frequent administration of chemotherapy at a lower dose and so whit less toxicity. Thus, this strategy could be attractive for elderly MBC patients. Aim of this analysis is to provide insights into mCHT's activity in a real-life setting of elderly MBC patients. Data of patients ≥ 75 years old included in VICTOR-6 study were analyzed. VICTOR-6 is a multicentre, Italian, retrospective study, which collected data on mCHT in MBC patients treated between 2011 and 2016. A total of 112 patients were included. At the beginning of mCHT, median age was 81 years (75-98) and in 33% of the patients mCHT was the first line choice. Overall Response Rate (ORR) and Disease Control Rate (DCR) were 27.9% and 79.3%, respectively. Median PFS ranged between 7.6 and 9.1 months, OS between 14.1 and 18.5 months. The most relevant toxicity was the hematological one (24.1%); severe toxicity (grade 3-4) ranged from 0.9% for skin toxicity up to 8% for hematologic one. This is a large study about mCHT in elderly MBC patients, providing insights to be further investigated in this subgroup of frail patients.

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.

Breast cancer screening adhesion among migrants: a matter of communication strategy?

Background

Migrants’ engagement to cancer screening programs is a relevant issue for universalistic health systems. To increase breast cancer screening coverage among migrant women, a public-private partnership involving a multidisciplinary team of Primary Care, Public Health, Hospital and private social workers has been built up in a district in Italy. The team worked in two steps, planning health promotion (HP) meetings addressing women in refugees’ reception programs and a web-based workshop involving intercultural mediators (IMs) and community health promoters.

Objectives

The workshop, involving 10 professionals among IMs and community health promoters, realized in 3 online meetings during March ‘22, aimed at identifying communication tools to enable migrants’ participation to breast cancer screening and increasing health literacy (HL) and cultural competence (CC) among the team. A participatory approach, supported by learning methods, such as storytelling and role-play, has been adopted to identify the major barriers to access to screening and public health messages. Participants worked on critical words and concepts, highlighted during HP meetings, accounting for HL, literacy, language skills, communication techniques and different perspectives about health and prevention.

Results

Several barriers, such as lack of knowledge on preventive initiatives and different approaches to health, decrease the perception of cancer risk. Others, like family and work duties, influence the adhesion. Fear or shame about the exam and linguistic issues are further hampering factors. Participants pointed out text, audio and video messages, in Italian and native plain language, as useful tools to explain the screening procedure and give relevant and practical information supported by simple and clear illustrations to diffuse via WhatsApp.

Conclusions

The intervention enabled the team to improve HL and CC defining suitable communication strategies for cancer screening programs.

Key messages

Alternative academic approaches for testing homologous recombination deficiency in ovarian cancer in the MITO16A/MaNGO-OV2 trial

Background

The detection of homologous recombination deficiency (HRD) can identify patients who are more responsive to platinum and poly ADP ribose polymerase inhibitors (PARPi). MyChoice CDx (Myriad) is the most used HRD test in ovarian cancer (OC). However, some limitations of commercial tests exist, because of the high rate of inconclusive results, costs, and the impossibility of evaluating functional resistance mechanisms.

Patients and methods

Two academic genomic tests and a functional assay, the RAD51 foci, were evaluated to detect HRD. One hundred patients with high-grade OC enrolled in the MITO16A/MaNGO-OV2 trial and treated with first-line therapy with carboplatin, paclitaxel, and bevacizumab were analyzed.

Results

The failure rate of the two genomic assays was 2%. The sensitivity in detecting HRD when compared with Myriad was 98.1% and 90.6%, respectively. The agreement rate with Myriad was 0.92 and 0.87, with a Cohen’s κ coefficient corresponding to 0.84 and 0.74, respectively. For the RAD51 foci assay, the failure rate was 30%. When the test was successful, discordant results for deficient and proficient tumors were observed, and additional HRD patients were identified compared to Myriad; sensitivity was 82.9%, agreement rate was 0.65, and Cohen’s κ coefficient was 0.18. The HRD detected by genomic assays and residual tumor at primary surgery and stage was correlated with progression-free survival at multivariate analysis.

Conclusions

Results suggest the feasibility of academic tests for assessing HRD status that show robust concordance with Myriad and correlation with clinical outcome. The contribution of the functional information related to the RAD51 foci test to the genomic data needs further investigation.

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Deficiency in homologous recombination repair of DNA generates genomic instability and permanent genomic changes.

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HRD status is fundamental for identifying OC patients suitable for platinum and PARPi treatment.

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HRD testing is considered a topic with urgent need for improvement, going beyond those available commercially.

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Within this study, two academic genomic tests and a functional assay, the RAD51 foci, were evaluated to detect HRD.

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Our tests compare favorably with the reference Myriad assay and correlate with the outcome of high-grade OC patients.

Lung ultrasound to detect cardiopulmonary interactions in acutely ill children

OBJECTIVE AND DESIGN

Our prospective observational study is the first study that evaluates the lung ultrasound (LUS) findings of cardiopulmonary interactions in acutely ill children with elevated pro-brain natriuretic peptide (BNP) levels, with the aim of establishing the specific LUS pattern in this category of patients without primary lung diseases.

METHODOLOGY

We prospectively analyzed epidemiological, clinical, laboratory, instrumental, and lung ultrasound parameters in acutely ill children aged 1 month to 18 years admitted to the Department of Pediatrics between March 2020 to August 2020. Among the acutely ill patients evaluated, only patients with pro-BNP > 300 pg/ml and who underwent LUS before the start of any treatment were included. They were stratified into three subcategories based on the diagnosis (A) cardiac disease, (B) systemic inflammatory disease/sepsis without functional and/or organic alterations of the myocardium, and (C) systemic inflammatory disease/sepsis and cardiac disease, and were classified into two groups based on the level of pro-BNP. We also enrolled patients belonging to two other categories (patients with primary infectious lung disease and completely healthy patients) analyzing their epidemiological, clinical, laboratory, instrumental parameters, and lung ultrasound findings and comparing them with those of acutely ill children.

RESULTS AND CONCLUSION

We found that LUS findings in these acutely ill children are different from the ultrasound pattern of other categories of children and in particular (1) children with acute lower respiratory tract infections and (2) healthy infants. The finding in a child of a sonographic interstitial syndrome with multiple, bright, long, separate, and nonconfluent B-lines/long vertical artifacts deriving from a normal and regular pleural line, in the absence of subpleural consolidations, is strongly predictive of cardiogenic pulmonary edema or pulmonary congestion in the course of systemic inflammatory disease/sepsis.

Quality of life of therapies for hormone receptor positive advanced/metastatic breast cancer: Regulatory aspects and clinical impact in Europe

In recent years, the number of trials incorporating health-related quality of life (HRQoL) data has increased. The impact of HRQoL on regulatory decision making in the European context and on clinical practice is not well established. We conducted an analysis of the role of QoL data extracted from the clinical trials of the drugs approved for hormone receptor positive/HER2-negative advanced/metastatic breast cancer (mBC). The results from the HRQoL were collected and a meta-analysis was performed to evaluate the impact of experimental drugs compared to standard treatments. The results showed a non-detrimental effect in HRQoL from the new treatments. As regards the approval process, from an examination of the European Medicine Agency (EMA) documents, HRQoL was reported nonextensively and contained and discussed in the European assessment reports (EPARs) for eleven trials in the approval process and cited in three cases in the EPARs and summary of medicinal product characteristics (SmPC). An effort should be made by all the stakeholders to increase the visibility of the HRQoL results in order to allow increased consideration in the approval process to make QoL data more easily and visibly available for the clinician and the patients. The evaluation should be reflected in the SmPC in order to increase the amount of information provided to the physician.

Metronomic chemotherapy (mCHT) in metastatic triple-negative breast cancer (TNBC) patients: results of the VICTOR-6 study

Purpose

Triple-negative breast cancer (TNBC) represents a subtype of breast cancer which lacks the expression of oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2): TNBC accounts for approximately 20% of newly diagnosed breast cancers and is associated with younger age at diagnosis, greater recurrence risk and shorter survival time. Therapeutic options are very scarce. Aim of the present analysis is to provide further insights into the clinical activity of metronomic chemotherapy (mCHT), in a real-life setting.

Methods

We used data included in the VICTOR-6 study for the present analysis. VICTOR-6 is an Italian multicentre retrospective cohort study, which collected data of metastatic breast cancer (MBC) patients who have received mCHT between 2011 and 2016. Amongst the 584 patients included in the study, 97 were triple negative. In 40.2% of the TNBC patients, mCHT was the first chemotherapy treatment, whereas 32.9% had received 2 or more lines of treatment for the metastatic disease. 45.4% out of 97 TNBC patients received a vinorelbine (VRL)-based regimen, which resulted in the most used type of mCHT, followed by cyclophosphamide (CTX)-based regimens (30.9%) and capecitabine (CAPE)-based combinations (22.7%).

Results

Overall response rate (ORR) and disease control rate (DCR) were 17.5% and 64.9%, respectively. Median progression free survival (PFS) and overall survival (OS) were 6.0 months (95% CI: 4.9–7.2) and 12.1 months (95% CI: 9.6–16.7). Median PFS was 6.9 months for CAPE-based regimens (95% CI: 5.0–18.4), 6.1 months (95% CI: 4.0–8.9) for CTX-based and 5.3 months (95% CI: 4.1–9.5) for VRL-based ones. Median OS was 18.2 months (95% CI: 9.1-NE) for CAPE-based regimens and 11.8 months for VRL- (95% CI: 9.3–16.7 and CTX-based ones (95%CI: 8.7–52.8). Tumour response, PFS and OS decreased proportionally in later lines.

Conclusion

This analysis represents the largest series of TNBC patients treated with mCHT in a real-life setting and provides further insights into the advantages of using this strategy even in this poor prognosis subpopulation.

Late congenital diaphragmatic hernia: is a significant challenge? A case series and review from literature

BACKGROUND

Late-presenting congenital diaphragmatic hernia (L-CDH) diagnosis is a challenge for its clinical various presentation. In literature radiologic misdiagnosis is up to 62%. The aim of this study is analyze clinical findings about our cases series in a particular setting of Pediatric Emergency Department (PED) and review of literature.

METHODS

We retrospectively analyzed the medical records of children older than 1 month, operated for L-CDH from November 2009 to December 2019 presented to PED, with a total of 20 children (5 Morgagni and 15 Bochdaleck).

RESULTS

The median age at diagnosis was 1,48 years. 50% patients had a history of previouses symtptoms with a mean duration of 243,75 days. In 30 % of cases associated anomalies were presented, mainly cardiovascular. 25% of patients had undergone to chest X-ray in past history with misdiagnosis of pneumonia, microganulia and broncovascular thickening. Misdiagnosis are manly among left sided Bochdaleck hernia. Respiratory distress alone or associated with vomiting is commonest acute symptom refered to PED. Respiratory symptoms were more common in younger children, while gastrointestinal ones in older children (not statistically differences p=0,8769). Post-operative recurrence were frequent only in cases of right sided CDH and comparing with left ones, there is a difference statistically significant (p=0.0476).

CONCLUSIONS

L-CDH should be suspected in cases of unexplained acute respiratory distress and vomiting, particulary when children are affected to associate cardiovascular malformation. In cases of patients with long previouses symptoms and various accesses to PED is important to emphasize history of respiratory distress, dysphagia and failure to thrive and should be considered a chest X-ray.

Phase II study of eribulin in combination with gemcitabine for the treatment of patients with locally advanced or metastatic triple negative breast cancer (ERIGE trial). Clinical and pharmacogenetic results on behalf of the Gruppo Oncologico Italiano di Ricerca Clinica (GOIRC)

Background

The combination of a microtubule inhibitor (eribulin) with a nucleoside analog (gemcitabine) may synergistically induce tumor cell death, particularly in triple negative breast cancer (TNBC) characterized by high cell proliferation, aggressive behavior, and chemo-resistance.

Patients and methods

This is an open-label, multicenter phase II study evaluating the combination of eribulin (0.88 mg/m²) plus gemcitabine (1000 mg/m²) on days 1 and 8 of a 21-day cycle as either first- or second-line treatment of locally advanced or metastatic TNBC. The primary endpoint was the objective response for evaluable patients. A prospective, molecular correlative study was carried out to assess the role of germinal BRCA pathogenic variants and single nucleotide polymorphisms (SNPs) in predicting efficacy and toxicity of the combination regimen.

Results

From July 2013 to September 2016, 83 evaluable patients were enrolled. They received a median number of six cycles of treatment. An overall response rate (ORR) of 37.3% (31 patients) was observed, with a complete response rate of 2.4% and a partial response rate of 34.9%; the clinical benefit rate was 48.8%. With a median follow-up of 28.8 months, the median response duration was 6.6 months, the median progression-free survival (PFS) was 5.1 months, and the median overall survival (OS) was 14.5 months. The most common grade 3-4 adverse events were aminotransferase elevation (in 25% of the patients) and neutropenia (in 23.8%). Women with BRCA1/2 pathogenic variants were associated with worse ORR, PFS, and OS than BRCA1/2 wild-type carriers. CYP3A4 and FGD4 SNPs were associated with increased risk of liver toxicity. Three different SNPs in CDA∗2, RRM1, and CYP2C8 genes were significantly associated with poorer OS.

Conclusions

The combination of eribulin and gemcitabine showed promising activity and a moderate toxicity profile in metastatic TNBC. BRCA status and pharmacogenetics tests may help identify patients with high probability of response with negligible toxicity.

EudraCT number

2012-003505-10.

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Eribulin plus gemcitabine showed a remarkable best ORR of 37.3% and a clinical benefit rate of 48.8%.

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The most common grade 3/4 toxicities were liver toxicity and neutropenia without febrile neutropenia.

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The study regimen partially lost its efficacy in patients harboring BRCA1/2 pathogenic variants.

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SNPs in CYP3A4 and FGD4 genes were associated with increased risk of liver toxicity.

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Three different SNPs in CDA∗2, RRM1, and CYP2C8 genes were significantly associated with poorer OS.

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.

Homologous Recombination Repair Deficiency and the Immune Response in Breast Cancer: A Literature Review

The success of cancer immunotherapy with immune checkpoint blockade (ICB) has demonstrated the importance of targeting a preexisting immune response in a broad spectrum of tumors. This is particularly novel and relevant for less immunogenic tumors, such as breast cancer (BC), where the efficacy of ICB was more evident in the triple-negative (TNBC) subtype, in earlier stages, and in association with chemotherapy. Tumors harboring homologous recombination DNA repair (HRR) deficiency (HRD) are supposed to have a higher number of mutations, hence a higher tumor mutational burden, which could potentially make them more sensitive to immunotherapy. However, the mechanisms involved in ICB sensitivity and patient selection are still yet to be defined in BC: whether the innate system could play a role and how the adaptive immunity could be linked with HRR pathways are the two key points of debate that we will discuss in this article. The aim of this review was to close the loop between what was found in clinical trial results so far, go back to laboratory theory and preclinical results and point out what needs to be clarified from now on.

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.

Metronomic chemotherapy for advanced breast cancer patients in the real world practice: Final results of the VICTOR-6 study

Metronomic chemotherapy (mCHT) refers to the minimum biologically effective dose of a chemotherapy agent given as a continuous dosing regimen, with no prolonged drug-free breaks, that leads to antitumor activity. Aim of the present study is to describe the use of mCHT in a retrospective cohort of metastatic breast cancer (MBC) patients in order to collect data regarding the different types and regimens of drugs employed, their efficacy and safety. Between January 2011 and December 2016, data of 584 metastatic breast cancer patients treated with mCHT were collected. The use of VRL-based regimens increased during the time of observation (2011: 16.8% - 2016: 29.8%), as well as CTX-based ones (2011: 17.1% - 2016: 25.6%), whereas CAPE-based and MTX-based regimens remained stable. In the 1st-line setting, the highest ORR and DCR were observed for VRL-based regimens (single agent: 44% and 88%; combination: 36.7% and 82.4%, respectively). Assuming VRL-single agent as the referee treatment (median PFS: 7.2 months, 95% CI: 5.3-10.3), the longest median PFS were observed in VRL-combination regimens (9.5, 95%CI 88.8-11.3, HR = 0.72) and in CAPE-single agent (10.7, 95%CI 8.3-15.8, HR = 0.70). The VICTOR-6 study provides new data coming from the real-life setting, by adding new information regarding the use of mCHT as an option of treatment for MBC patients.

Abstract P1-14-05: Phase II study of eribulin in combination with gemcitabine for the treatment of patients with locally advanced or metastatic triple negative breast cancer (ERIGE Trial). Clinical and pharmacogenetic results on behalf of the Gruppo Oncologico Italiano di Ricerca Clinica (GOIRC)

Background: There are no well-established chemotherapy regimens for metastatic triple negative breast cancer. The combination of a microtubule inhibitor (eribulin) with a nucleoside analog (gemcitabine) may synergistically induce tumor cell death, especially in tumors like triple negative breast cancers (TNBC) characterized by high cell proliferation, aggressive tumor behavior, and chemo-resistance.

Materials and Methods:This is an open-label, national multicenter phase II study evaluating the combination of eribulin (0.88 mg/m2) plus gemcitabine (1000 mg/m2) on day 1 and 8, q21 as either first- or second-line treatment of locally advanced or metastatic TNBC.The primary endpoint was the objective response rate (ORR) for evaluable patients (pts). The study was designed according to the Simon's two stage optimal design. We chose the lower activity (p0) of 0.20 and target activity level (p1) of 0.35. A prospective, molecular correlative study has been being carried out on germinal DNA of study population to assess the role of BRCA mutations and single nucleotide polymorphisms (SNPs) in predicting efficacy and toxicity of the combination regimen.

Results: From July 2013 to September 2016, 83 evaluable pts (37 in the first stage, 46 in the second one) were enrolled. They received a median number of 6 cycles of treatment (range 1-24). The ORR (CR+PR) was 37.35% (90% CI: 28.47-46.93) and the clinical benefit rate (CR+PR+SD ≥ 24wks) was 48.78% (90% CI: 39.24%-58.39%). The most common grade 3-4 adverse events (&gt; 10% of patients) were neutropenia and liver toxicity. With a median follow-up of 28.8 months, the median progression-free survival (PFS) and overall survival (OS) were 5.1 months (95% CI: 4.2-7.0) and 14.7 months (95% CI: 10.2-20.0), respectively. BRCA1/2 deleterious mutations were observed in 15 (22%) out of 68 genotyped pts. Women with BRCA1/2 mutations were associated with worse ORR, PFS and OS than those with BRCA1/2 wild-type. A panel of SNPs in genes of study drug metabolism pathways was evaluated. Among these, CYP3A4 392A &gt;G and FGD4 2044236G&gt;A SNPs were associated with greater liver toxicity by logistic regression analysis. Furthermore, CDA*2 79A&gt;C, RRM1 2455 A&gt;G, and CYP2C8 416G&gt;A SNPs were associated with poorer overall survival by Cox proportional hazards model.

Conclusions:The combination of eribulin and gemcitabine shows promising activity and a moderate toxicity profile in metastatic TNBC. BRCA status and pharmacogenetics tests may help identify pts with high probability of response with negligible toxicity.

Citation Format: Musolino A, Cavanna L, Boggiani D, Zamagni C, Frassoldati A, Caldara A, Rocca A, Gori S, Piacentini F, Berardi R, Brandes AA, Foglietta J, Villa F, Pellegrino B, Todeschini R, Tognetto M, Naldi N, Bortesi B, Boni L, Montemurro F, Ardizzoni A. Phase II study of eribulin in combination with gemcitabine for the treatment of patients with locally advanced or metastatic triple negative breast cancer (ERIGE Trial). Clinical and pharmacogenetic results on behalf of the Gruppo Oncologico Italiano di Ricerca Clinica (GOIRC) [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 P1-14-05.

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.

Efficacy and safety of Everolimus and Exemestane in hormone-receptor positive (HR+) human-epidermal-growth-factor negative (HER2-) advanced breast cancer patients: New insights beyond clinical trials. The EVA study

BACKGROUND

The BOLERO-2 trial reported efficacy and safety of Everolimus (EVE) and Exemestane (EXE) combination in HR+ advanced breast cancer (ABC) patients. The BALLET trial further evaluated the safety of EVE-EXE in HR+ ABC patients, without reporting efficacy data. Aim of the EVA real-life study was to collect data of efficacy and safety of EVE-EXE combination in the clinical setting, as well as exploring efficacy according to EVE Dose-Intensity (DI) and to previous treatment with Fulvestrant.

PATIENTS AND METHODS

This study aimed to describe the outcome of ABC pts treated with EVE-EXE combination in terms of median duration of EVE treatment and ORR in a real-life setting.

RESULTS

From July 2013 to December 2015, the EVA study enrolled 404 pts. Median age was 61 years (33-83). Main metastatic sites were: bone (69.1%), soft tissue (34.7%) and viscera (33.2%). Median number of previous treatments was 2 (1-7). 43.3% of the pts had received Fulvestrant. Median exposure to EVE was 31.0 weeks (15.4-58.3) in the whole population. No difference was observed in terms of EVE exposure duration according to DI (p for trend = 0.27) or type of previous treatments (p = 0.33). ORR and Disease Control Rate (DCR) were observed in 31.6% and 60.7% of the patients, respectively, with the lowest ORRs confined in CHT pre-treated patients or in those who received the lowest DI of EVE. Grade 3-4 adverse events (AEs) were reported in 37.9% of the patients. Main AEs were: stomatitis (11.2%), non-infectious pneumonitis - NIP (3.8%), anaemia (3.8%) and fatigue (3.2%).

CONCLUSIONS

The EVA study provided new insights in the use of EVE-EVE combination in HR+ ABC pts many years after the publication of the pivotal trial. The combination is safe and the best response could be obtained in patients receiving the full dose of EVE and/or after hormone-therapy as Fulvestrant in ABC.

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.

Abstract P1-07-23: Prognostic impact of HER2 overexpression/amplification in women with pT1a N0 M0 breast cancer with known screening status: Results from a multicenter population-based cancer registry study

Introduction: Outcomes for women with pT1aN0M0 breast cancers (BC) may vary by biologic subtype. A higher proportion of HER2-positive BCs diagnosed in the interval between scheduled screening rounds has been proposed to account for the more aggressive behaviour of interval cancers (IC) compared with screen-detected (SD) tumors. No data are available on the prognostic role of HER2-positive status in a general population of pT1aN0M0 breast tumors with known screening status.

Methods: All incident pT1aN0M0 BCs (n=874), systematically collected by the Cancer Registries of Emilia Romagna Region (northern Italy) and diagnosed in women aged 50-69 from 2003 to 2009 were evaluated. Screening status was ascertained by reference to the Emilia Romagna Breast Cancer Screening Program (ERBSP) database. Patients unexposed to screening, with HER2 unknown primary tumor and/or who received adjuvant chemotherapy or trastuzumab were excluded from analysis.

Results: Twenty percent of patients had HER2-positive tumors. Fifty-three percent of the entire study population were SD cancers, while 18% were ICs. Tumors with high histologic grade, high proliferative rate, negative estrogen receptor status, or HER2-positive status were more likely to be diagnosed in the interval between screening. At a median follow-up of 84 months, the 5-year invasive disease-free survival (IDFS) rates were 89% and 95% in patients with HER2-positive and HER2-negative tumors, respectively (P = 0.025). Notably, HER2-positive ICs showed poorer IDFS than HER2-positive SD tumors (84% vs. 95%, respectively; P = 0.04). No difference in IDFS rates were observed between HER2-positive SD cancers and HER2-negative SD cancers. Multivariable analysis of candidate prognostic factors for IDFS will be reported.

Conclusions: In a general population of pT1aN0M0 early BCs with known screening status, IC detection may identify patients with HER2-positive pT1aN0M0 tumors in whom the rate of recurrence justifies consideration for systemic, anti-HER2, adjuvant therapy.

Citation Format: Musolino A, Michiara M, Boggiani D, Sikokis A, Rimanti A, Pellegrino B, Silini EM, Campanini N, Barbieri E, Sgargi P, Falcini F, Pinto C. Prognostic impact of HER2 overexpression/amplification in women with pT1a N0 M0 breast cancer with known screening status: Results from a multicenter population-based cancer registry study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-23.

Abstract P2-04-01: HER2 Status as Predictor of Mammographic Screening Detection: Comparison of Interval-and Screen-Detected Breast Cancers

Background: To determine whether markers of poor prognosis are associated with risk of breast cancer diagnosis in the interval between screening examinations, we estimated the effect of the mode of detection on distribution of breast cancer molecular subtypes using population cancer registry data.

Material and Methods: Subjects (n = 641) comprised all breast cancers systematically collected by the Cancer Registry of Parma Province and diagnosed in women aged 50-69, from 2004 to 2007. These included 370 screen-detected and 271 symptomatic breast cancers (63 women with interval cancers and 208 who had not attended screening). We used logistic regression to determine whether interval cancers were associated with selected clinical and biologic characteristics. We also estimated the relative risk of cause-specific fatality and disease-free survival (DFS) by each resulting predictive factor (screen-detected compared to either symptomatic or interval cancers).

Results: Interval-detected cancers occurred more in younger women and were of more advanced tumor stage than screen-detected cancers. In unconditional logistic regression models adjusted for age and tumor stage, tumors with high histologic grade (odds ratio[OR] = 2.2; 95% CI =1.0-5.4), high proliferation rate (OR =2.7; 95% CI =1.5-4.8), or positive HER2 status (OR =2.6; 95% CI =1.3-5.1) were more likely to surface in the interval between screening examinations. After adjusting for various potential biases, women with screen-detected breast cancer had a substantial survival advantage over those with symptomatic breast cancer. In a multivariate model, positive HER2 status independently predicted poor DFS when the mode of cancer detection was included as covariate in addition to age, histologic grade, proliferation rate, and tumor stage. Conclusions: This is the first population-based cancer registry study demonstrating that HER2-positive tumors account for a substantial proportion of mammographic screening failure to detect breast cancer. Our data indicate that molecular subtype distribution of screen-detected breast cancer differs from that of interval cancers and accounts in part for the better outcome of screen-detected cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-04-01.

Abstract P2-17-01: Phase II Study of Bevacizumab in Combination with Docetaxel and Capecitabine for the First-Line Treatment of Patients with Locally Recurrent or Metastatic Breast Cancer

Background: Docetaxel (T; Taxotere) with capecitabine (X) is active against metastatic breast cancer (MBC); bevacizumab (B) has demonstrated efficacy with taxanes in the first-line setting. This study was conducted to assess the efficacy and safety of TX-B in patients (pts) with MBC. Patients and methods: In this single-arm, multicenter phase II study, pts received first-line bevacizumab 15 mg/kg and docetaxel 60 mg/m2 on day 1, plus capecitabine 900 mg/m2 twice per day on days 1-14 every 21 days. The treatment was administrated for 3 cycles and in case of objective response or stable disease at that time, pts were treated with 3 additional cycles. More courses of chemotherapy were administered at Investigator's discretion. Bevacizumab was continued until progressive disease, patient refusal, or unacceptable toxicity. Primary end point was progression-free survival (PFS) and secondary end points were tumor response rate (RR), overall survival (OS), and toxicity.

Results: We report data from the first 30 pts enrolled. Median age was 54 (37-72). Eight (27%) pts had triple-negative disease, while 18 (60%) were hormone-receptor positive. HER2 status was recognized as negative in 25 (84%) pts. TX-B was administered for a median of seven cycles. Five complete and 13 partial responses were observed (overall RR 60%). Median response duration was 12 months. Median OS and PFS were 26 and 11 months, respectively. Grade 3/4 adverse events included tromboembolism (10%), neutropenia (23%), hand-foot syndrome (13%), stomatitis (10%). The median TX doses administered per cycle were 60 mg/m2 and 660 mg/m2, respectively. Ten (33%) pts required dose reductions of docetaxel, while capecitabine dose was reduced in 15 (50%) pts. Results of all the 80 assessable pts entered in the study will be presented at the meeting.

Conclusion: TX-B demonstrated significant activity with an acceptable toxicity profile. Maintenance therapy with B is possible for a long period of stable tumor disease.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-17-01.

Abstract P5-12-05: 9 Weeks vs 1 Year Adjuvant Trastuzumab in Combination with Chemotherapy: Preliminary Cardiac Safety Data of the Phase III Multicentric Italian Study Short-HER

Introduction: Several large randomized trials have shown the superiority of combining trastuzumab with chemotherapy versus chemotherapy alone as adjuvant treatment for HER2+ breast cancer patients. We are running a large phase III trial comparing two different trastuzumab durations (Short-HER study). We are reporting the preliminary cardiac safety data.

Methods: The Short-HER study is a phase III, multicentric, Italian trial where 2500 HER2+ breast cancer patients will be randomized to: Arm A (Long) 4 courses of anthracycline based chemotherapy (AC or EC) followed by 4 courses of docetaxel in combination with trastuzumab, followed by 14 additional courses of 3-weekly trastuzumab; or Arm B (Short) 3 courses of 3-weekly docetaxel in combination with weekly trastuzumab followed by FEC x3. this is a non-inferiority trial with DFS and OS as primary end points, and 2-yr failure rate and incidence of cardiac events as secondary end points. Left ventricular ejection fraction (LVEF) is measured at baseline, at the end of each sequence of chemotherapy in both arms, and after 9 and 12 months since randomization thereafter. A cardiac event (CE) was defined as the occurrence of any of the followings: 1) LVEF decrease of more than 15 percentage points from baseline ; 2) LVEF decrease of more than 10 percentage points with absolute value below 50%; 3) symptomatic cardiac failure; 4) other cardiac side effects of grade 2 or more.

Results: 510 patients from 69 Italian centers have been randomized so far, 251 in arm A (long) and 259 in Arm B (Short). 146 patients enrolled in arm A and 150 patients enrolled in arm B have received at least 3 months of therapy, and are eligible for the present analysis. In arm A (long), 20 patients (13.7%) experienced a CE: 12 patients experienced a LVEF decline of &gt; 15 percentage points (5 patients with LVEF below 50%, one patient with concomitant atrial fibrillation); 3 patients had a LVEF decline of &gt;10 percentage points with an absolute value below 50%. One patient had symptomatic cardiac failure. Two patients developed Grade 2 hypertension. Two patients developed Grade 2 arrhythmia.

In arm B (short), 11 patients (7.3%) experienced a CE: 7 patients had a LVEF decline of &gt; 15 percentage points; one patient had a LVEF decline of &gt; 10 percentage points with an absolute value below 50%. Three patients developed Grade 2 arrhythmia

Conclusions: This is a non-inferiority study designed on the assumption that a shorter treatment duration is associated with a significantly lower incidence of cardiac events. With 9 clinically relevant CEs (symptomatic cardiac failure or LVEF below 50%) in arm A (Long) and 1 in arm B (Short), these preliminary data support the assumption, and recruitment is ongoing.

Supported by Agenzia Italiana del FArmaco (AIFA).

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-12-05.

Multifactorial CNS relapse susceptibility in HER2-positive breast cancer patients: First results from a population-based registry study

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Background: A series of retrospective studies have reported a higher incidence of central nervous system (CNS) metastases in HER-2-positive (HER-2+) metastatic breast cancer. Trastuzumab, which does not cross the blood-brain barrier, has been associated with this increased risk. Methods: The aim of this study was to evaluate incidence, survival, and risk factors of CNS metastases in the incident breast cancer population systematically collected by the Tumor Registry of Parma Province over the 4-year period, 2004–2007. Study endpoints were: any distant metastasis as first event; CNS metastasis as first event; CNS metastasis at any time. Associations between CNS metastases and HER-2 status in the entire population and between trastuzumab and CNS metastases in HER-2+ patients (pts) were estimated. A multivariate analysis was performed to test the effect of covariates. Results: We evaluated the total resident population (n = 1500) of breast cancer pts diagnosed during the period 2004–2007 in Parma Province. Two-hundred and twenty-five pts (15%) were HER-2+ (IHC 3+/FISH amplified). Of these, 100 pts were treated with adjuvant trastuzumab-based therapy. At a median follow-up of 36 months from the diagnosis, the incidence of CNS relapse was 3% (1.3% as first recurrence). The median time to death from the diagnosis of CNS metastases was 25 months. Among the HER-2+ pts, there was a significant association between trastuzumab and subsequent CNS metastases (p = 0.02). However, in multivariate analysis, HER-2 status regardless of trastuzumab therapy was found to be the only independent predictive factor for CNS metastases (either as first or as subsequent recurrences; p < 0.01). Conclusions: This is the first population-based registry study analyzing CNS metastases in breast cancer in relation to tumor biological features, systemic treatment, and clinical outcome. Based on our results, HER-2 status independently distinguishes pts with a higher risk of CNS metastases. It is however presumable that, in some cases, improvements in systemic control and overall survival associated with trastuzumab-based therapy lead to an “unmasking” of CNS relapse that would otherwise have remained clinically silent prior to a patient's death.

No significant financial relationships to disclose.

Intracranial hematopoiesis in a patient with aids-related central nervous system lymphoma and severe pancytopenia

The case here reported reflects the difficulty in diagnosing meningeal extramedullary hematopoiesis (EMH), which clinically appeared concomitantly with primary cerebral lymphoma and occurred in a patient with HIV infection and severe pancytopenia. Pancytopenia secondary to HIV infection could be hypothesized as a predisposing factor for the ectopic development of hematopoietic tissue outside the bone marrow. Although rare, intracranial EMH should always be considered in the differential diagnosis of headache and other endocranial hypertension symptoms in patients with chronic bone marrow dysfunction.

Immunoglobulin G fragment C receptor polymorphisms and response to trastuzumab-based treatment in patients with HER-2/neu-positive metastatic breast cancer

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Background: A potential mechanism of action of the humanized anti-HER-2/neu monoclonal antibody Trastuzumab involves antibody-dependent cellular cytotoxicity (ADCC) with the activation of immune effector cells via their immunoglobulin G fragment C receptors (FcγRs). Trastuzumab has been shown to engage both activation (FcγRIIIa; FcγRIIa) and inhibitory (FcγRIIb) antibody receptors on myeloid cells and several FcγR polymorphisms have been identified that may affect the antibody-dependent cytotoxicity of natural killer cells and macrophages. Methods: Forty consecutive HER-2/neu-positive (FISH+) metastatic breast cancer patients receiving a trastuzumab-based treatment (combined with paclitaxel for the majority) were examined for the FcγRIIIa 158 valine (V)/phenylalanine (F), FcγRIIa 131 histidine (H)/arginine (R), and FcγRIIb 232 isoleucine (I)/threonine (T) polymorphisms. A PCR-RFLP based assay using genomic DNA was performed for FcγRIIIa and FcγRIIa genotyping, while PCR-SSCP methods using complementary DNA were utilized for FcγRIIb. Patients’ peripheral blood mononuclear cells were drawn before treatment initiation and their trastuzumab-mediated killing function was measured by 51Cr release using a HER-2/neu-expressing human breast cancer cell line as a target. The results were then correlated with clinical outcome of these patients. Results: Median age was 60 years (range 26–83 years). Thirty-six (90%) patients received a trastuzumab-based treatment as first-line therapy. The overall clinical benefit rate (CR+PR+SD) was 65% (95% Confidence Interval: 62–71%), including 8 (20%) complete and 11 (27.5%) partial responses. Median survival was 22.3 mo with a median PFS of 7 mo. Trastuzumab-based treatment was well tolerated and no changes in cardiac function were observed. Conclusions: This study evaluates for the first time the potential role of FcγR polymorphisms in predicting response to trastuzumab-based treatment. Results according to this study purpose will be presented at the meeting.

No significant financial relationships to disclose.