RediScore: Prospective validation of a pipeline for homologous recombination deficiency analysis

Tumors harboring homologous recombination deficiency (HRD) are considered optimal candidates for poly(ADP-ribose) polymerase 1 (PARP) inhibitor treatment. Such deficiency can be detected by analyzing breast cancer type (BRCA)1/2 gene mutations, as well as mutations in other genes of the homologous recombination pathway. The algorithmic measurement of the HRD effect by identifying genomic instability (GI) has been used as biomarker. As compared with the direct measurement of somatic gene alterations, this approach increases the number of patients who could benefit from PARP inhibitor treatment. In the present study, the performance of the Oncoscan CNV assay, accompanied by appropriate bioinformatic algorithms, was evaluated for its performance in GI calculation and was compared with that of a validated next-generation sequencing (NGS) test (myChoice HRD test). In addition, the clinical utility of the GI score (GIS) and BRCA1/2 tumor analysis were investigated in a cohort of 444 patients with ovarian cancer. For that reason, single nucleotide polymorphism (SNP) arrays and appropriate bioinformatics algorithms were used to calculate GIS in 29 patients with ovarian cancer with known GIS status using a validated NGS test. Furthermore, BRCA1/2 analysis results were compared between the aforementioned assay and the amplicon-based Oncomine™ BRCA Research Assay. BRCA1/2 analysis was performed in 444 patients with ovarian cancer, while GIS was calculated in 175 BRCA1/2-negative cases. The bioinformatics algorithm developed for GIS calculation in combination with NGS BRCA1/2 analysis (RediScore), and the OncoscanR pipeline exhibited a high overall agreement with the validated test (93.1%). In addition, the Oncomine NGS assay had a 100% agreement with the validated test. The BRCA1/2 mutation frequency was 26.5% in the examined patients with ovarian cancer. GIS was positive in 40% of the BRCA1/2-negative cases. The RediScore bioinformatics algorithm developed for GIS calculation in combination with NGS BRCA1/2 analysis is a viable and effective approach for HRD calculation in patients with ovarian cancer, offering a positive prediction for PARP inhibitor responsiveness in 55% of the patients.

Only 32.3% of Breast Cancer Families with Pathogenic Variants in Cancer Genes Utilized Cascade Genetic Testing

BACKGROUND

Hereditary cancer predisposition syndromes are responsible for approximately 5-10% of all diagnosed cancer cases. In order to identify individuals at risk in a cost-efficient manner, family members of individuals carrying pathogenic alterations are tested only for the specific variant that was identified in their carrier relative. The purpose of this study was to investigate the clinical use and implementation of cascade family testing (CFT) in families of breast cancer patients with pathogenic/likely pathogenic variants (PVs/LPVs) in cancer-related predisposition genes.

METHODS

Germline sequencing was carried out with NGS technology using a 52-gene panel, and cascade testing was performed by Sanger sequencing or MLPA.

RESULTS

In a cohort of 1785 breast cancer patients (families), 20.3% were found to have PVs/LPVs. Specifically, 52.2%, 25.1%, and 22.7% of patients had positive findings in high-, intermediate-, and low-penetrance breast cancer susceptibility genes, respectively. Although CFT was recommended to all families, only 117 families (32.3%) agreed to proceed with genetic testing. Among the first-degree relatives who underwent CFT, 70.3% were female, and 108 of 121 (89.3%) were cancer free. Additionally, 42.7%, 36.7%, and 20.6% were offspring, siblings, and parents of the subject, respectively. Our data suggest that CFT was mostly undertaken (104/117, 88.8%) in families with positive findings in high-risk genes.

CONCLUSIONS

Cascade family testing can be a powerful tool for primary cancer prevention by identifying at-risk family members. It is of utmost importance to implement genetic counseling approaches leading to increased awareness and communication of genetic testing results.

Copy Number Variations (CNVs) Account for 10.8% of Pathogenic Variants in Patients Referred for Hereditary Cancer Testing

BACKGROUND/AIM

Germline copy number variation (CNV) is a type of genetic variant that predisposes significantly to inherited cancers. Today, next-generation sequencing (NGS) technologies have contributed to multi gene panel analysis in clinical practice.

MATERIALS AND METHODS

A total of 2,163 patients were screened for cancer susceptibility, using a solution-based capture method. A panel of 52 genes was used for targeted NGS. The capture-based approach enables computational analysis of CNVs from NGS data. We studied the performance of the CNV module of the commercial software suite SeqPilot (JSI Medical Systems) and of the non-commercial tool panelcn.MOPS. Additionally, we tested the performance of digital multiplex ligation-dependent probe amplification (digitalMLPA).

RESULTS

Pathogenic/likely pathogenic variants (P/LP) were identified in 464 samples (21.5%). CNV accounts for 10.8% (50/464) of pathogenic variants, referring to deletion/duplication of one or more exons of a gene. In patients with breast and ovarian cancer, CNVs accounted for 10.2% and 6.8% of pathogenic variants, respectively. In colorectal cancer patients, CNV accounted for 28.6% of pathogenic/likely pathogenic variants.

CONCLUSION

In silico CNV detection tools provide a viable and cost-effective method to identify CNVs from NGS experiments. CNVs constitute a substantial percentage of P/LP variants, since they represent up to one of every ten P/LP findings identified by NGS multigene analysis; therefore, their evaluation is highly recommended to improve the diagnostic yield of hereditary cancer analysis.

Abstract P1-11-01: Trastuzumab deruxtecan vs treatment of physician’s choice in patients with HER2-low unresectable and/or metastatic breast cancer: Subgroup analyses from DESTINY-Breast04

Background: DESTINY-Breast04 demonstrated that the HER2 targeting antibody–drug conjugate trastuzumab deruxtecan (T-DXd) significantly prolonged progression-free survival (PFS) and overall survival (OS) vs treatment of physician’s choice (TPC) in patients (pts) with HER2-low (immunohistochemistry [IHC] 1+ or IHC 2+/in situ hybridization negative) metastatic breast cancer (mBC) in pts in the hormone receptor−positive (HR+) cohort and all pts (HR+ and HR-; median PFS, 9.9 vs 5.1 months [mo], hazard ratio: 0.50; median OS, 23.4 vs 16.8 mo, hazard ratio: 0.64; both P < 0.0001; Modi et al. N Engl J Med 2022). Objective response rate (ORR) with T-DXd was ≥50% across cohorts. These subgroup analyses examine pt history and disease characteristics that may correlate with response to therapy.

Methods: N = 557 pts with centrally confirmed HER2-low mBC were randomized 2:1 to T-DXd or TPC. Randomization was stratified by HER2 status (IHC 1+ vs 2+), 1 vs 2 prior lines of chemotherapy, and HR+ (with vs without prior treatment with cyclin-dependent kinase 4/6 inhibitor [CDK4/6i]) vs HR−. With the exception of the PFS and OS analyses by prior CDK4/6i use, all other described efficacy analyses were assessed post-hoc.

Results: Benefit of T-DXd vs TPC was consistent in pts with or without prior CDK4/6i use (Table 1). Pts with high disease burden (ie, ≥3 metastatic sites) also benefited from T-DXd vs TPC (Table 2). There was a small subgroup (n = 22) among all pts (HR+ [n = 18] and HR− disease [n = 4]) with rapid progression prior to enrollment (disease progression within 6 mo of concluding a prior course of chemotherapy in early breast cancer). T-DXd showed responses in 7/14 (50%) pts in this subgroup vs 0/8 with TPC; this subgroup also had prolonged median PFS with T-DXd vs TPC (Table 3). Efficacy data for HER2 IHC 1+ vs 2+ and prior chemotherapy subgroups will be presented. Median OS was not reached for many subgroups (insufficient events in each group [data not shown]); however, subgroups in general showed OS benefit consistent with the primary analysis. With T-DXd, rates of interstitial lung disease/pneumonitis were similar in pts with/without prior CDK4/6i use.

Conclusions: T-DXd treatment for HER2-low mBC in the phase 3 study DESTINY-Breast04 showed consistent efficacy independent of disease burden, prior CDK4/6i treatment, or rapid progression status. ILD is an important identified risk and requires proactive monitoring and management. These data continue to support the use of T-DXd as the new standard of care across subgroups of pts with HER2-low mBC.

Editorial Acknowledgment

Under guidance of the authors, assistance in medical writing and editorial support was provided by Eileen McIver, PhD, and Soniya Patel, PhD, of ApotheCom, and was funded by Daiichi Sankyo.

Funding

This study was funded by Daiichi Sankyo and AstraZeneca.

Table 1. Efficacy by Prior CDK4/6i Treatment in Pts With HER2-Low Breast Cancer, HR+ Cohort.

Table 2. Efficacy by Disease Burdena in Pts With HER2-Low Breast Cancer, ITT.

Table 3. Efficacy by Rapid Progressor Statusa in Pts With HER2-Low Breast Cancer, ITT.

Citation Format: Nadia Harbeck, Shanu Modi, William Jacot, Toshinari Yamashita, Joo Hyuk Sohn, Maria Vidal, Junji Tsurutani, Naoto T. Ueno, Aleix Prat, Naoki Niikura, Binghe Xu, Hope Rugo, Konstantinos Papazisis, Javier Cortés, Ian Krop, Dhiraj Gambhire, Lotus Yung, Yibin Wang, Jasmeet Singh, David Cameron. Trastuzumab deruxtecan vs treatment of physician’s choice in patients with HER2-low unresectable and/or metastatic breast cancer: Subgroup analyses from DESTINY-Breast04 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-11-01.

Ribociclib and palbociclib-induced erythema multiforme: a case report

Cyclin-dependent kinase 4/6 inhibitors (CKIs), ribociclib, palbocilb and abemaciclib, have been approved in combination with endocrine therapy for the treatment of hormone receptor-positive and human epidermal growth factor 2-negative advanced or metastatic breast cancer. Severe dermatological adverse events are rare with these agents; however, they require direct recognition and management in order not to become life-threatening. Erythema multiforme (EM) belongs to a dermatopathic spectrum that includes immune-mediated, widespread hypersensitivity reaction, which occurs with varying degrees of severity and affects the skin and/or the mucosa. We hereby present a case of ribociclib- and palbociclib-related EM. We sought to report this case given the implication of two agents from the same drug class in EM onset. We also aim to emphasize the breadth of mechanisms of actions of CKIs, with an impingement in the immune system as well, and the importance of promptly identifying and handling such skin toxicities.

Prognostic Significance of Low HER2 Expression in Patients With Metastatic Hormone Receptor-positive Breast Cancer Treated With First Line CDK4/6 Inhibitors: A Greek Multicenter Real-world Data Analysis

BACKGROUND/AIM

Low expression of HER2 has defined a new "HER2-low" subgroup of breast cancer with distinct clinicopathological characteristics and both prognostic and predictive implications. The impact of low HER2 expression in metastatic hormone receptor-positive HER2-negative breast cancer treated with first-line CDK4/6 inhibitors has not been studied. Using real-world patient data, we aimed to identify prognostic differences in this patient population according to HER2 expression with immunohistochemistry.

PATIENTS AND METHODS

We retrospectively analyzed 191 patients from 5 Oncology Department databases in Thessaloniki, Greece, with hormone receptor-positive HER2-negative metastatic breast cancer treated with CDK4/6 inhibitors in the first line, for whom detailed immunohistochemical HER2 data could be retrieved.

RESULTS

Median progression-free survival was numerically different among the different HER2 subgroups (3.35 years for HER2 0 tumors, 2.18 years for HER2 +1 tumors, 1.74 years for HER2 +2/ISH-negative tumors), but this difference was not statistically significant (p=0.477). Median PFS was statistically significantly longer in patients without visceral metastases (5.45 years) compared to patients with visceral metastases (1.61 years) (p=0.017). Median PFS was also statistically significantly longer in patients taking an aromatase inhibitor (2.99 years) compared to patients taking fulvestrant (1.33 years) (p<0.0001). There were no statistically significant differences in the other subgroups examined.

CONCLUSION

CDK4/6 inhibitors are equally effective as first-line treatment agents, regardless of the exact level of HER2 expression. Numerical differences, however, do exist among the different HER2 subgroups, and merit further evaluation in future studies to better study this phenomenon.

Treatment With Adjuvant Abemaciclib Plus Endocrine Therapy in Patients With High-risk Early Breast Cancer Who Received Neoadjuvant Chemotherapy: A Prespecified Analysis of the monarchE Randomized Clinical Trial

Importance

Patients selected to receive neoadjuvant chemotherapy (NAC) are usually those at higher risk of relapse, and there is a need to find better therapeutic options for these patients.

Objective

To determine the efficacy and safety outcomes for patients with hormone receptor (HR)-positive, ERBB2 (formerly HER2)-, high-risk early breast cancer enrolled in the randomized clinical trial monarchE who received NAC.

Design, Setting, and Participants

The monarchE randomized clinical trial was a multicenter, phase 3, open-label study that evaluated adjuvant treatment with abemaciclib plus endocrine therapy (ET) compared with ET alone in patients with HR+, ERBB2-, and node-positive early breast cancer who were at high risk of recurrence. Patients were recruited between July 2017 and August 2019 from 603 sites in 38 countries. This subgroup analysis was performed with primary outcome data, with a cutoff date of July 8, 2020.

Intervention

Enrolled patients were randomized (1:1) to receive standard of care ET for at least 5 years with or without treatment with abemaciclib (150 mg, twice daily) for 2 years (treatment period) or until criteria were met for discontinuation.

Main Outcomes and Measures

Prior chemotherapy (NAC vs adjuvant vs none) was a stratification factor in monarchE, and and a prespecified exploratory analysis included outcomes in patients who received NAC. The data presented in this article are from the primary outcome analysis (395 invasive disease-free survival [IDFS] events; cutoff date, July 8, 2020; median follow-up 19 months [IQR, 15.6-23.9 months]). Invasive disease-free survival (the primary end point of monarchE) and distant relapse-free survival (DRFS) were evaluated using the Cox proportional hazard model and Kaplan-Meier method.

Results

Of the 5637 patients (mean [SD] age, 49.9 [10.6] years; 2046 women [99.5%]; 462 Asian [22.8%], 54 Black [2.7%], and 1473 White participants [70.8%]) enrolled in monarchE, 2056 (37%) received treatment with NAC. In this subgroup, treatment with abemaciclib and ET demonstrated clinically meaningful benefit in IDFS (hazard ratio, 0.61; 95% CI, 0.47-0.80) and DRFS (hazard ratio, 0.61; 95% CI, 0.46-0.81), which corresponded with an absolute improvement of 6.6% in 2-year IDFS rates and 6.7% in 2-year DRFS rates. A consistent treatment benefit was observed across subgroups of pathological breast tumor size or number of positive lymph nodes at surgery.

Conclusions and Relevance

In the randomized clinical trial monarchE, treatment with adjuvant abemaciclib combined with ET demonstrated a clinically meaningful improvement in IDFS and DRFS for patients with HR+, ERBB2-, node-positive, high-risk early breast cancer who received NAC before trial enrollment.

Trial Registration

ClinicalTrials.gov Identifier: NCT03155997.

Prognostic Significance of Low HER2 Expression in Patients With Early Hormone Receptor Positive Breast Cancer

BACKGROUND/AIM

A possible role of antibody-drug conjugates against tumors with low HER2-expression, leads to the emergence of a new "low-HER2" classification in breast cancer, encompassing tumors from the hormonal-receptor-positive and the triple-negative subgroups. There is a need for data (clinical trial data and real-world evidence) that will accurately describe this population, the risk of recurrence and the possible benefit of HER2 targeted therapies.

PATIENTS AND METHODS

We retrospectively analyzed 949 patients from our Department databases, with hormonal receptor-positive and HER2-negative early breast cancer, for whom detailed data for immunohistochemical HER2-staining could be retrieved.

RESULTS

HER2-low expression was detected in 66.6% of patients (472 IHC +1 and 160 IHC +2 and ISH-negative). Lobular, or mixed lobular and ductal cancers had a statistically significantly lower chance of being HER2-low when compared to pure infiltrative ductal carcinomas (53.1% vs. 69.3% respectively). HER2-low status was not prognostic for recurrence-free survival or response to neoadjuvant chemotherapy. There was a non-significant trend for increased risk of recurrence for HER2-low, compared to HER2-0, in patients with lobular or mixed lobular and ductal carcinomas (HR=2.192, 95% CI=0.819-5.912).

CONCLUSION

Low expression of HER2 in hormonal receptor-positive early breast cancer does not affect prognosis but may lead to a shorter progression-free-survival in lobular and mixed ductal and lobular cancers. Despite optimal management, a large proportion of hormonal receptor-positive patients will relapse. Targeting HER2 in HER2-low cancers may offer a potential additional treatment strategy to improve survival of this group.

Abstract P2-09-10: Different CNVs account for 10.4% of pathogenic variants in 1418 patients referred for hereditary breast cancer testing

Background: Breast cancer is the most frequently diagnosed cancer in women and about 10% of breast cancer cases are hereditary. BRCA1 and BRCA2 are the genes most frequently associated with Hereditary Breast Cancer, although there are numerous other genes, such as PALB2, CHEK2 and ATM, that require to be considered as well. Germline Copy Number Variation (CNV) is one mutation type that is an important contributor to hereditary breast cancer. Nowadays, next-generation sequencing (NGS) technologies has contributed to multi-gene panel analysis used in clinical practice. Methods: In total, 1418 individuals were tested for breast cancer predisposition, using a solution-based capture approach. Targeted NGS was performed with a panel of 36 genes. The capture-based approach allowed for computational analysis of CNVs from NGS data. Results: We investigate the performance of the CNV module of the commercial software suite SeqPilot (JSI Medical Systems) and the non-commercial tool panelcn.MOPS. Both algorithms are specifically developed for CNV analysis of sequencing data reporting 99-100% sensitivity and up to 100% specificity for the prediction of CNVs up to the level of a single gene exon. All CNVs detected with these algorithms were then verified experimentally using the MLPA technique as an orthogonal assay. At least one pathogenic/likely pathogenic variant was identified in 289 samples (20.4%). CNVs accounted for 10.4% (30/289), referring to the deletion of one or more exons of a gene. Interestingly, 50% of deletions were single exon and approximately 36% of CNVs were detected in genes other than BRCA1/2. In specific, of the 30 CNVs detected, 60% occurred in BRCA1, 3.3% in BRCA2, 20% in CHEK2, 6.7% in FANCA, 6.7% in PMS2, and 3.3% in ATM. The majority of CNVs in BRCA1 were deletions of exons 19, 22, and 22-23 whereas deletions of exons 9-10 were the most common deletions in CHEK2. Detailed information of all CNVs detected is provided in Table 1.

Conclusions: Our results suggest that CNV analysis should not be restricted to BRCA1/2 due to the significant proportion of CNVs (36%) in additional breast cancer predisposition genes. Furthermore, in silico CNV detection tools provide a cost-effective and feasible methodology for the identification of CNVs from NGS experiments. This outlines the clinical utility of comprehensive genetic testing that includes full sequencing and CNV analysis in hereditary breast cancer facilitating personalized management decisions for patients.

Table 1.Pathogenic Copy Number Variations (CNVs) identified in this studyGeneHGVS nomenclatureOther nomenclature# detectedATMNM_000051:c.(-30+1_-29-1)_(331+1_332-1)deldeletion of exons 2-41BRCA1NM_007294:c.(5467+1_5468-1)-(*1_?)deldeletion of exon 237BRCA1NM_007294:c.(5406+1_5407-1)_(*1_?)deldeletion of exons 23-245BRCA1NM_007294:c.(5193+1_5194-1)-(5277+1_5278-1)deldeletion of exon 196BRCA2NM_000059:c.(6841+1_6842-1)_(7007+1_7008-1)deldeletion of exons 12-131CHEK2NM_007194:c.(908+1_909-1)_(1095+1_1096-1)deldeletion of exons 9-104CHEK2NM_007194:c.(792+1_793-1)_(846+1_847-1)deletion of exon 72FANCANM_000135:c.(1626+1_1627-1)_ (2852+1_2853-1)deldeletion of exons 18-291FANCANM_000135:c.(893+1_894-1)_(1359+1_1360-1)deldeletion of exons 11-141PMS2NM_000535: c.(903+1_904-1)_(988+1_989-1)deldeletion of exon 91PMS2NM_000535:c.(705+1_706-1)_(2006+1_2007-1)deldeletion of exons 7-111

Citation Format: Nikolaos Tsoulos, Konstantinos Agiannitopoulos, Georgia Pepe, Eirini Papadopoulou, Georgios N Tsaousis, Despina Apostolopoulou, Angeliki Meintani, Vassileios Venizelos, Christos Markopoulos, Rodoniki Iosifidou, Sofia Karageorgopoulou, Christos Christodoulou, Ioannis Natsiopoulos, Konstantinos Papazisis, Maria Vasilaki-Antonatou, Eleftherios Kabletsas, Amanta Psyrri, Stylianos Giassas, Dimitrios Ziogas, Efthalia Lalla, Anna Koumarianou, Christos Papadimitriou, Vahit Ozmen, Sualp Tansan, Kerim Kaban, Tahsin Ozatlı, Dan Tudor Eniu, Angelica Chiorean, Alexandru Blidaru, George Nasioulas. Different CNVs account for 10.4% of pathogenic variants in 1418 patients referred for hereditary breast cancer testing [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-09-10.

Revisiting the Implications of Positive Germline Testing Results Using Multi-gene Panels in Breast Cancer Patients

BACKGROUND/AIM

The use of multi-gene panels for germline testing in breast cancer enables the estimation of cancer risk and guides risk-reducing management options. The aim of this study was to present data that demonstrate the different levels of actionability for multi-gene panels used in genetic testing of breast cancer patients and their family members.

MATERIALS AND METHODS

We performed an analysis in our clinical database to identify breast cancer patients undergoing genetic testing. We reviewed positive results in respect of risk estimation and management, cascade family testing, secondary findings and information for treatment decision-making.

RESULTS

A total of 415 positive test reports were identified with 57.1%, 18.1%, 10.8% and 13.5% of individuals having pathogenic/likely pathogenic variants in high, moderate, low and with insufficient evidence for breast cancer risk genes, respectively. Six point seven percent of individuals were double heterozygotes.

CONCLUSION

Germline findings in 92% of individuals are linked to evidence-based treatment information and risk estimates for predisposition to breast and/or other cancer types. The use of germline findings for treatment decision making expands the indication of genetic testing to include individuals that could benefit from targeted treatments.

Follow-up of tissue genomics in BRCA1/2 carriers who underwent prophylactic surgeries

PURPOSE

The genomic status of non-malignant tissues from carriers of pathogenic germline BRCA1/2 (gBRCA1/2) variants may reveal information towards individualized prophylaxis. We performed spatiotemporal tissue genotype comparisons in a real-life cohort of gBRCA1/2 carriers of Greek origin, who underwent multiple risk-reducing/prophylactic surgeries at various time points.

METHODS

Fifty-three women (median age 36 years) within cancer families were observed for up to 37.5 years; 43 were cancer carriers and 10 were healthy carriers. Histology review and genotyping were performed for 187 paraffin tissues (average: 3.5 per carrier) including 46 carcinomas (40 breast) and 141 non-malignant breast and gynecological samples.

RESULTS

High allelic imbalance (AI) and somatic pathogenic TP53 variants were present in cancer carriers only (p values < 0.0001). High AI was associated with gBRCA1/2 indels (p < 0.0001) and gBRCA2 alterations (p = 0.0109). Somatic (pathogenic) variants were infrequently shared between non-malignant tissues and matched carcinomas. Aberrations of gBRCA1 variant heterozygosity were noticed in tissues from cancer carriers only (13/43, 30.2%). These pertained to classic LOH (neoplastic lesions in 9/43 carriers, 20.9%) and under-representation of the germline variants (5 samples, 4 non-malignant, all in the breast). Both aberrations coexisted in matched samples in one case. Over time, germline variant heterozygosity prevailed in non-malignant tissues; intra-carrier genomic alterations were aggravated (21.1%), ameliorated (26.3%) or remained stable.

CONCLUSION

This real-life case study supports the need to address tissue genotypes from prophylactic surgeries in combination with polygenic scores towards personalized prophylaxis. To this end, knowing the traditionally classified pathogenic potential of a gBRCA1/2 variant may not be enough.

Abemaciclib combined with adjuvant endocrine therapy in patients with high risk early breast cancer who received neoadjuvant chemotherapy (NAC)

517

Background: monarchE, a phase 3, open-label, randomized study evaluating abemaciclib combined with adjuvant endocrine therapy (ET) compared to ET alone in patients with HR+, HER2-, high risk early breast cancer (EBC), resulted in a statistically significant improvement in invasive disease-free survival (IDFS) (HR = 0.713; 95% CI: 0.583, 0.871). NAC is used in patients with HR+, HER2- EBC at higher risk of recurrence despite often limited response, suggesting a need for enhanced adjuvant ET. Methods: Patients with ≥4 positive notes (LNS), or 1-3 LNS and either Grade 3 disease, tumor size ≥5 cm, or central Ki-67 ≥20% were eligible. Prior chemotherapy (NAC, adjuvant, none) was one of the stratifications factors. Prior therapy and tumor characteristics prior to study entry were collected. Here, we present the results of the prespecified subgroup of patients who received NAC. Results: Out of 5,637 randomized patients, 2056 (36.5%) received NAC. For 84.8%, the chosen regimen included anthracycline + cyclophosphamide + taxane, for 4.4%, it included anthracycline + taxane. A total of 1044 (50.8%) patients who received NAC had a radiologic tumor size between 2-5 cm and 599 (29.1%) had tumors ≥5 cm at diagnosis. 6.2%, 49.4% and 36.7% of patients had tumors with histologic Grade 1, 2, 3 respectively. 55.2% of patients had LNS ≥4+ and 44.4% had 1-3+ LNS. Central Ki-67 prior to NAC was ≥20% in 64.8% of patients with available Ki-67 results (664 (32.3%) patients had missing Ki-67 results). Evaluation of clinical and pathological measures of response will be presented. A multivariate cox regression analysis of IDFS in the intent-to-treat (ITT) population, identified prior chemotherapy as prognostic, suggesting patients who received NAC were at risk of a worse outcome. Primary outcome efficacy data for patients who received NAC are shown in the table below. Abemaciclib + ET demonstrated treatment benefit in terms of IDFS vs ET alone (HR: 0.614 95% CI: 0.473, 0.797) with 2-year IDFS rates of 87.2% vs 80.6%, respectively. The addition of abemaciclib to ET resulted in an improvement in distant relapse-free survival (DRFS) (HR: 0.609, 95% CI: 0.459, 0.809), with 2-year DRFS rates of 89.5% and 82.8%, respectively. Safety profile was similar to the overall safety population. Conclusions: Patients with HR+, HER2- EBC who received NAC were noted to be at a higher risk of recurrence. In this subgroup, abemaciclib combined with ET demonstrated a clinically meaningful treatment benefit in IDFS and DRFS, which was numerically greater than in the ITT population. Safety data were consistent with abemaciclib safety profile. Clinical trial information: NCT03155997. [Table: see text]

Cardiac safety of neoadjuvant chemotherapy with epirubicin and cyclophosphamide followed by docetaxel/pertuzumab/trastuzumab for HER2-positive breast cancer patients

PURPOSE

Early-stage, HER2-positive breast cancer is increasingly treated with neoadjuvant chemotherapy (NAC). After the positive results of the Neosphere trial, the standard of care has been the combination of chemotherapy with two anti-HER2 agents, trastuzumab and pertuzumab. Many oncologists use the sequence of four cycles of anthracycline-containing regimen followed by four cycles of taxane with the two monoclonals. We report here the cardiac safety of four cycles of epirubicin with cyclophosphamide followed by four cycles of docetaxel with trastuzumab and pertuzumab, given at the neoadjuvant setting in early, HER2-positive breast cancer.

METHODS

We retrospectively collected data from the medical records of patients treated at our clinic between 2014 and 2020.

RESULTS

It total, 55 patients treated with the same regimen were identified. There were 20 estrogen receptor (ER)-negative and 35 ER-positive patients. Complete pathologic response was observed in 64.8% of the patients. After a median cardiac follow-up of 2.61 years, and a total of 283 echocardiograms, there was only one recorded asymptomatic Left Ventricular Ejection Fraction (LVEF) fall > 25% and no symptomatic left ventricular systolic dysfunction. LVEF consistently dropped during treatment, but the drop was not significant enough to necessitate treatment interruption, and improved during follow-up.

CONCLUSION

Our data confirm the effectiveness and cardiac safety of the aforementioned neoadjuvant regimen.

Clinical Utility of Functional RNA Analysis for the Reclassification of Splicing Gene Variants in Hereditary Cancer

BACKGROUND

Classification of splicing variants (SVs) in genes associated with hereditary cancer is often challenging. The aim of this study was to investigate the occurrence of SVs in hereditary cancer genes and the clinical utility of RNA analysis.

MATERIAL AND METHODS

1518 individuals were tested for cancer predisposition, using a Next Generation Sequencing (NGS) panel of 36 genes. Splicing variant analysis was performed using RT-PCR and Sanger Sequencing.

RESULTS

In total, 34 different SVs were identified, 53% of which were classified as pathogenic or likely pathogenic. The remaining 16 variants were initially classified as Variant of Uncertain Significance (VUS). RNA analysis was performed for 3 novel variants.

CONCLUSION

The RNA analysis assisted in the reclassification of 20% of splicing variants from VUS to pathogenic. RNA analysis is essential in the case of uncharacterized splicing variants, for proper classification and personalized management of these patients.

Highlighting the importance of multidisciplinary approach: A rare case of primary periurethral poorly differentiated carcinoma

OBJECTIVE

Tumors in the periurethral area can be a rare clinical entity with many difficulties not only in the diagnosis, as well as in the treatment plan. Skene's gland adenocarcinoma accounts for less than 0.003% of all female urethral malignant neoplasms.

CASE REPORT

This report describes an extremely rare case of woman with a poorly differentiated carcinoma arising from the periurethral glands.

CONCLUSIONS

Reporting of such rare cases enhance the understanding of the biological behavior of such tumors and the best treatment plan as well. This case report highlights the need for multidisciplinary approach of such rare cases, the lack of experience for such cases and the fact that the optimal treatment plan is very critical for the best prognosis of these patients.

Analysis of hereditary cancer syndromes by using a panel of genes: novel and multiple pathogenic mutations

Background

Hereditary cancer predisposition syndromes are responsible for approximately 5–10% of all diagnosed cancer cases. In the past, single-gene analysis of specific high risk genes was used for the determination of the genetic cause of cancer heritability in certain families. The application of Next Generation Sequencing (NGS) technology has facilitated multigene panel analysis and is widely used in clinical practice, for the identification of individuals with cancer predisposing gene variants. The purpose of this study was to investigate the extent and nature of variants in genes implicated in hereditary cancer predisposition in individuals referred for testing in our laboratory.

Methods

In total, 1197 individuals from Greece, Romania and Turkey were referred to our laboratory for genetic testing in the past 4 years. The majority of referrals included individuals with personal of family history of breast and/or ovarian cancer. The analysis of genes involved in hereditary cancer predisposition was performed using a NGS approach. Genomic DNA was enriched for targeted regions of 36 genes and sequencing was carried out using the Illumina NGS technology. The presence of large genomic rearrangements (LGRs) was investigated by computational analysis and Multiplex Ligation-dependent Probe Amplification (MLPA).

Results

A pathogenic variant was identified in 264 of 1197 individuals (22.1%) analyzed while a variant of uncertain significance (VUS) was identified in 34.8% of cases. Clinically significant variants were identified in 29 of the 36 genes analyzed. Concerning the mutation distribution among individuals with positive findings, 43.6% were located in the BRCA1/2 genes whereas 21.6, 19.9, and 15.0% in other high, moderate and low risk genes respectively. Notably, 25 of the 264 positive individuals (9.5%) carried clinically significant variants in two different genes and 6.1% had a LGR.

Conclusions

In our cohort, analysis of all the genes in the panel allowed the identification of 4.3 and 8.1% additional pathogenic variants in other high or moderate/low risk genes, respectively, enabling personalized management decisions for these individuals and supporting the clinical significance of multigene panel analysis in hereditary cancer predisposition.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5756-4) contains supplementary material, which is available to authorized users.

Ιmpact of sunitinib-induced hypothyroidism on survival of patients with metastatic renal cancer

BACKGROUND

Sunitinib plays an important role in managing the metastatic renal cell cancer (mRCC). Sunitinib-induced hypothyroidism is a common side-effect of the drug. There have been attempts to link hypothyroidism with a better clinical outcome in sunitinib-treated (mRCC) patients. Our aim was to relate the impact of hypothyroidism to the survival of these patients.

METHODS

We have evaluated 70 patients with mRCC that received sunitinib as a first line treatment. Thyroid-stimulating hormone (TSH) was measured at baseline, after 15 days of treatment (day-15) and at the end of the second cycle (day-75). Biomarker data and correlations with response were analysed with Microsoft Excel. Comparison results from Student's t-test with a p less than 0.05 were considered statistically significant. Kaplan-Meyer and log-rank tests were performed using GraphPad Prism 5 for Windows.

RESULTS

Regarding the response to treatment, a progression-free survival (PFS) of 9.47 months and an overall survival (OS) of 22.03 months were demonstrated. Our data are consistent with published data by other authors. On day-15 from the beginning of the treatment an important number of patients exhibited a TSH elevation. On day-15 42.86% had a TSH over the upper normal limit and 50.0% at the end of the second cycle (day-75). TSH increased earlier in patients that exhibited an objective response (× 3.33 times the baseline values on day-15) than patients that exhibited disease stabilisation (× 2.18) or disease progression (× 1.59). Early increases in TSH were associated with a longer PFS (11.92 vs. 8.82 months, p = 0.0476) and a longer OS (3.10 vs. 1.08 years, p = 0.0011).

CONCLUSIONS

Early TSH-increase is associated with a clinical benefit. The patients that showed at least a twofold increase of their baseline TSH, responded to therapy by stabilisation or by regression of disease. This is the only study to our knowledge which shows that early increases - 2 weeks from starting the treatment - in TSH levels have a prognostic value. Both PFS and OS of the patients who demonstrated a higher than a twofold rise were significantly longer than the PFS and the OS of the patients that presented a lower or no TSH-increase.

Abstract P4-03-07: Analysis of hereditary cancer syndromes by using a panel of genes: Novel and multiple pathogenic mutations

BACKGOUND: Hereditary cancer predisposition syndromes are believed to be responsible for approximately 5-10% of all diagnosed cancer cases. In the past, single genes analysis of certain high risk genes was used for the determination of the genetic cause of cancer heritability in certain families. The selection of genes was mainly based on the family history of the individuals analyzed and included only highly associated genes (e.g. the BRCA1 and BRCA2 genes for families with breast cancer history. Nowadays though, the application of Next Generation Sequencing (NGS) technology has facilitated multigene panel analysis and is widely used in clinical practice, for the identification of individuals with cancer predisposition gene mutations.

AIM: The aim of this study was to investigate the extent and nature of mutations in 36 genes implicated in hereditary cancer predisposition in individuals referred for testing in our lab.

MATERIALS & METHODS: In total, 1197 individuals were referred for testing in our lab in the past four years from Greece, Romania and Turkey. The analysis of genes involved in hereditary cancer predisposition was performed using two NGS approaches. The first 451 individuals were analyzed using an amplicon based sequencing method (26 gene panel), while the following 746 individuals were analyzed using a capture based method (33 gene panel). Genomic DNA was enriched for targeted regions of 36 genes involved in hereditary predisposition to cancer included in both versions of the panel (APC, BMPR1A, BRCA1, BRCA2, CDH1, CDK4, CDKN2A, EPCAM, MEN1, MLH1, MSH2, MSH6, MUTYH, PALB2, PMS2, PTEN, RET, SMAD4, STK11, TP53, VHL, ATM, BRIP1, CHEK2, NBN, RAD51C, RAD51D, BARD1, BLM, CHEK1, ABRAXAS1 (FAM175A), MRE11 (MRE11A), NF1, RAD50, RAD51B, XRCC2). Sequencing was carried out using the Illumina NGS technology. Reads were aligned to the reference sequence (GRCh37), and sequence changes were identified and interpreted in the context of a single clinically relevant transcript. The presence of large genomic rearrangements was investigated by computational analysis of NGS results and the use of MLPA for 13 genes. All clinically significant observations were confirmed by orthogonal technologies.

RESULTS: In total, a pathogenic mutation was identified in 259 of the 1197 individuals (21.6%) analyzed while a VUS was identified in 35.7% of the cases. Clinically significant mutations were identified in 29 of the genes analyzed. Concerning the mutation distribution among individuals with positive findings, 44.7% of them were located in BRCA1/2 genes whereas 20.9%, 19.9%, and 14.5% in high, moderate and low risk genes respectively. In addition to BRCA1 and BRCA2 genes other highly mutated genes were CHEK2 (10.6%), PALB2 (7.1%), MUTYH (7.1%) and ATM (4.3%). Of note is that 25 of the 259 positive individuals (9.7%) carried clinically significant mutations in two different genes and 5.8% had a large genomic rearrangement (LGR).

CONCLUSIONS: Our results support the clinical significance of analysis of a panel of genes involved in hereditary cancer predisposition. In our cohort, analysis of this panel allowed for the identification of 8.3% additional pathogenic variants in moderate/low risk genes, enabling personalized management of these individuals.

Citation Format: Tsoulos N, Tsaousis GN, Papadopoulou E, Agiannitopoulos K, Pepe G, Kambouri S, Apessos A, Diamantopoulos N, Floros T, Iosifidou R, Katopodi O, Koumarianou A, Markopoulos C, Papazisis K, Venizelos V, Xanthakis I, Xepapadakis G, Banu E, Eniu DT, Negru S, Stanculeanu DL, Ungureanu A, Ozmen V, Tansan S, Tekinel M, Yalcin S, Nasioulas G. Analysis of hereditary cancer syndromes by using a panel of genes: Novel and multiple pathogenic mutations [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 P4-03-07.

Axillary Lymph Node Tattooing and Targeted Axillary Dissection in Breast Cancer Patients Who Presented as cN+ Before Neoadjuvant Chemotherapy and Became cN0 After Treatment

INTRODUCTION

Targeted axillary dissection (TAD) is an alternative to axillary dissection for breast cancer patients who presented as cN+ before neoadjuvant chemotherapy (NAC) and became cN0 after treatment. TAD is defined as the removal of sentinel lymph nodes (SLNs) along with the pre-NAC marked positive nodes. Tattooing is an option to mark positive nodes. In this study we aimed to investigate the identification rate of tattooed nodes during surgery, correspondence between tattooed nodes and SLNs, and difficulties and pitfalls of the method.

PATIENTS AND METHODS

In 75 patients who were cN+, with axillary lymph nodes known to have or suspected to have disease were tattooed pre-NAC with a sterile carbon suspension (Spot). After NAC completion all patients became cN0 and underwent TAD as an axillary staging procedure.

RESULTS

SLNs were identified successfully in 70 of 75 patients (93.3%). All tattooed nodes were identified successfully intraoperatively in 71 of 75 patients (94.6%). Retrieval of all tattooed nodes in surgical specimens was achieved in 74 patients (98.6%). Correspondence between tattooed nodes and SLNs was observed in 53 of 70 patients (75.3%). In 34 patients (45.3%) the number of pigmented nodes in pathological examination was greater than the number of initially tattooed nodes, indicating the possibility of tattoo ink migration.

CONCLUSION

Tattoo of axillary lymph nodes is a feasible, accurate, and low-cost method of positive node marking pre-NAC. Pathological confirmation of black pigment in the lymph nodes excised is not by itself warranty of retrieval of all marked node because of tattoo ink migration from one node to another. Intraoperative identification using visual inspection is essential.

Abstract 1359: Somatic involution of pathogenic BRCA1 germline mutations

There is currently a wealth of data on the tumor genomic contexture from BRCA1/2 carriers, particularly breast and ovarian carcinomas. By contrast, little attention has as yet been paid to the genomic status of cancer-related normal tissues from these individuals. Here, we investigated the status of pathogenic BRCA1 germline mutations (GM) in breast (B) and gynecologic (GYN) tissues.

Methods: We examined 121 DNA samples (48 B; 36 GYN; 37 tumors) from an equal number of paraffin blocks obtained upon prophylactic or debulking surgery from 44 BRCA1/2 carriers (mean age 38 yrs, range 24-62; 43 BRCA1 carriers). Six women had never had cancer manifestation (CM). At the time of surgery, 32 were cancer-free but had received neo- or adjuvant chemotherapy, and 6 had concurrent cancer without prior treatment. Following multimethod DNA quality control, mutation validation and sample identity match to exclude false negatives, we interrogated GM presence in tissues in comparison to clinicopathologic data and tumor genotypes (60-gene panel; mean read depth over 800).

Results: In 19 samples from 13 BRCA1 carriers, including 13 normal B/GYN and 6 tumors, the germline mutation was present at frequencies lower than 5% (observed with the integrated genome viewer) up to 12%, or it was undetectable with Sanger sequencing and multiplex PCR. This condition, termed GM-loss, was present in 13 GYN, 12 of which in the histologically normal tube, and in only 3 B with fibrocystic disease (p=0.0210). It was also present in one ovarian thecoma but it was absent in usual or atypical hyperplasia in B. GM-loss was observed in 9/55 normal tissues from breast cancer and in 4/6 normal tissues from ovarian cancer patients, while it was absent in the normal tissues from women without CM (p=0.0002). GM-loss mostly affected the BRCA1 BRCT functional domain (p&lt;0.0001) and concerned large deletions (10/17 samples), small indels (5/32; 15.6%) and less so single-nucleotide substitutions (4/66; 6.0%; p&lt;0.0001). Normal tissue GM-loss was rather localized, e.g., in 10 patients with multiple samples it was present in only one B or fallopian tube. It was, however, related to the status of concurrent ovarian tumors in 3/6 cases. In the normal tube of these patients, next to the low-frequency GM a somatic pathogenic BRCA1 mutation was present at 25-41% allelic frequency; the same was observed in one breast tumor after neoadjuvant chemotherapy. Three of the replaced GMs were indels, two corresponded to the well-known BRCA1 p.Q1777fs, and all novel mutations were missense.

Conclusions: We observed BRCA1 GM-loss in normal tissues, breast and mostly fallopian tube, in about 30% of the carriers in the present cohort, all with previous or concurrent cancer. The phenomenon seems analogous to the GM reversion described in tumors but, as shown, it may also occur in the absence of prior treatment. Its origin and impact on cancer dynamics and therapeutic approaches seem worth further pursuing with functional studies.

Citation Format: Vassiliki Kotoula, Efterpi Demiri, Florentia Fostira, Eleni Vrettou, Kyriaki Papadopoulou, Ioannis Tikas, Konstantinos Papazisis, Thomas Zaramboukas, Asimina Asimaki-Vlachopoulou, Spyridon Miliaras, Elena Fountzilas, Ananias Ananiadis, Sofia Chrisafi, Christos Poulios, Ioannis Natsiopoulos, Aris Tsiftsoglou, George Fountzilas. Somatic involution of pathogenic BRCA1 germline mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1359.

Abstract P3-04-04: Germline and somatic mutation status in tissues from BRCA1/2 carriers

Background – aim: In carriers of BRCA1/2 pathogenic mutations (mut), it is expected that the germline mut is present in all tissues, particularly in normal; the somatic mut status in normal tissues from these patients is usually not addressed. We investigated the mut status in normal and tumor tissues in a real-life cohort of BRCA1/2 carriers who underwent prophylactic surgery.

Methods: All 53 women had known BRCA1/2 germline mut that had been assessed independently; 42 had previous cancer manifestation (PCM); all had prophylactic mastectomy; 22 had prophylactic hystero-salpingo-oophorectomy. By using a 60-gene NGS panel, we examined the mut status of 231 samples, 39 peripheral blood and 192 paraffin tissues (FFPE: 46 tumors, out of which 43 breast; 97 normal breast [NB]; 49 normal ovary and salpinx [NGYN]). Germline mut status was interrogated in tissues with the above panel, Sanger sequencing and a multiplex PCR protocol for large exonic deletions, along with extensive FFPE DNA quality control (QC) to exclude false negatives.

Results: Eight patients carried germline BRCA2 and 45 BRCA1 mut (29 in the BRCT-domain; 31 substitutions/indels). We identified somatic mut in 85% of the tumors and in 64% of the normal samples; mut were found significantly more often (p=0.003) and in higher numbers (p&lt;0.001) in NGYN than in NB. In NB and NGYN, top 3 genes with somatic mut were BRCA2 (28%), BRCA1 (17%), TP53 (7%). In tumors, somatic mut were most frequent in TP53 (49%; p&lt;0.001) and BRCA1 (38%; p=0.039). Among all tissue types, the 5 tumors post-neoadjuvant treatment had the highest and NB the lowest mut load (p=0.001). In NB and NGYN, mut load was not affected by PCM or BRCA1 mut domain but it was higher in BRCA1 vs. BRCA2 carriers (p=0.027) and in those with BRCA1 substitutions/indels vs. exon deleting and skipping mut (p&lt;0.001). In tumors, germline BRCA1 substitutions/indels were associated with higher mut load (p=0.014). We validated germline mut status in all blood samples and in 111 tissue samples that passed FFPE DNA QC from 40 patients. The germline mut was not found in 14 samples (4 breast tumors; 3 NB; 7 NGYN) from 10 (25%) patients, all BRCA1 carriers, 9 with germline mut in the BRCT-domain. The only non-BRCT domain germline mut that was lost in one breast tumor, p.V1234fs, was replaced by the R1751* (validated), again in the BRCT domain. In normal tissues, those with lost germline mut had significantly less somatic mut compared to those with preserved germline mut (p&lt;0.001).

Conclusions: In BRCA1/2 carriers, somatic mut in BRCA genes and TP53 are present in normal breast and GYN tissues, more frequently in the latter, and seem associated with the mutated gene and with the type of mut in the germline. The mut status of normal breast tissue does not seem to be affected by neoadjuvant chemotherapy for breast cancer. The observed BRCA1 germline mut loss, particularly in normal tissues, may be approached as a negative selection for the inherited mut; similarly to the described germline mut reversion after chemotherapy, tissues may react to deleterious effects of haploinsufficiency, which needs functional validation.

Citation Format: Kotoula V, Demiri E, Fostira F, Vrettou E, Papadopoulou K, Tikas I, Papazisis K, Zaramboukas T, Asimaki-Vlachopoulou A, Miliaras S, Fountzilas E, Ananiadis A, Chrisafi S, Poulios C, Natsiopoulos I, Tsiftsoglou A, Fountzilas G. Germline and somatic mutation status in tissues from BRCA1/2 carriers [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 P3-04-04.

Real-world experience of everolimus as second-line treatment in metastatic renal cell cancer after failure of pazopanib

Aim

We aimed to provide real-life data on the outcomes of metastatic renal cell carcinoma (mRCC) patients treated with everolimus as second-line treatment after failure of first-line pazopanib.

Patients and methods

Data from the medical charts of mRCC patients from 8 centers in Greece and Spain were reviewed. All patients had received or were continuing to receive second-line everolimus treatment after failure of first-line treatment with pazopanib. No other previous therapies were allowed. The primary end point was the determination of progression-free survival (PFS).

Results

In total, 31 patients were enrolled. Of these, 26% had performance status (PS) >0, 88% were of intermediate/poor Memorial Sloan-Kettering Cancer Center (MSKCC) risk group, and only 61% had undergone prior nephrectomy. Median PFS was 3.48 months (95% CI: 2.37–5.06 months). Median overall survival (OS) from everolimus initiation was 8.9 months (95% CI: 6.47–13.14 months). Median OS from pazopanib initiation was 14.78 months (95% CI: 10.54–19.08 months). Furthermore, 32% of patients temporarily discontinued everolimus due to adverse events (AEs), and 22% of patients discontinued everolimus permanently due to toxicity. Most common toxicities were anemia (29%), stomatitis (26%), pneumonitis (19%), and fatigue (10%). Moreover, 14 AEs (27%) were graded as 3 or 4 and were reported by 13 patients (42%).

Conclusion

This study provides data exclusively on the sequence pazopanib–everolimus in mRCC. Everolimus has a favorable safety profile and is active. The short PFS and OS could be attributed to the fact that the pazopanib–everolimus sequence was mainly offered to patients with adverse prognostic features, resulting in a modest increase in the combined OS of our population.

Genomic features of normal tissues from prophylactic surgery in BRCA1/2 mutation carriers

e13055

Background: Genomic alterations in normal tissues from pathogenic germline BRCA1/2 mutation (mut) carriers are as yet poorly described. We investigated the genomic status of normal breast (NB) and hystero-salpingo-oophorectomy (GYN) tissues removed upon prophylactic surgery in a real-life cohort of BRCA1/2 carriers. Methods: By using targeted NGS we examined the mut status of 220 samples (39 peripheral blood and 181 paraffin tissue) from 53 BRCA1/2 carriers who underwent prophylactic surgery, 42 with and 11 without prior cancer manifestation (PCM). We compared germline BRCA1/2 mut status with tumor, NB and GYN mut status. Results: Eight patients carried germline BRCA2 and 45 BRCA1 mut. Somatic mut were most frequent in BRCA2 (28%), BRCA1 (17%), TP53 (7%) among 136 NB and GYN samples; and, in TP53 (49%; p < 0.001) and BRCA1 (38%; p = 0.039) among 45 tumor samples. Among all tissue types, the 85 NB had the lowest mut load (p = 0.001). In NB and GYN, mut load was higher in BRCA1 vs. BRCA2 carriers (p = 0.027) and in those with BRCA1 substitutions/indels vs. exon deleting and skipping mut (p < 0.001). In tumors, only germline BRCA1 substitutions/indels were associated with higher mut load (p = 0.014). Preservation of germline mut in tissues was assessable in 84 samples from 26 patients. The germline mut was lost in 8 tumor and NB samples from 6 patients (23%) with PCM. Somatic deleterious mut in the BRCA1 BRCT-domain emerged in two such cases; the rest had combinations of TP53, MRE11A and NF1 mut. GYN samples from these patients retained the germline mut and presented the highest mut load among all examined samples (p < 0.001). Conclusions: Somatic mut in normal tissues from BRCA1/2 carriers are affected by the inherited mutated gene and by the type of the germline mut concerning BRCA1. Germline BRCA1 mut may be substituted by somatic mut in tumor and normal tissues, in an organ specific manner. Mutagenesis in tumors and normal tissues appear to be driven by different pathways. Our findings shed new light on the biological impact of BRCA1/2 mut in tissues.

Abstract P1-03-08: Different genomic rearrangements account for 17% of BRCA1/2 mutations in Greece

AIM: The aim of this study was to further delineate the extent and nature of mutations in the BRCA1 and BRCA2 genes, responsible for hereditary breast and ovarian cancer in Greek families.

MATERAILS & METHODS: Genomic DNA was isolated from whole peripheral blood of patients referred to our center for mutation analysis of the BRCA1 and BRCA2 genes. Patients were included on the basis of affected family members, types of cancer present in the family and age at diagnosis of breast cancer in the proband. Families were subdivided into high, medium and low risk depending on the number of affected family members, types of cancer diagnosed in the family and age at diagnosis of affected family members. In total, 675 families have been analyzed by our group in the past 4 years. Mutation analysis in all cases included sequencing of the coding region and the splice sites of the two genes. In addition, MLPA analysis was carried in 585 of the patients.

RESULTS: In total, a pathogenic mutation has been identified in 12% of the 675 patients analyzed. Of the 78 mutations identified in total, 13 (17%) were large genomic rearrangements. These were deletions of exons 8, 20, 23, 23-24 and the entire BRCA1 gene, in addition to a duplication of exons 3-8 of the BRCA1 gene. As far as BRCA2 is involved deletions of exons 3, 15 and the entire BRCA2 gene were detected. All deletions were confirmed by use of other MLPA probe sets and/or relative quantitation by Real Time PCR. Of the rearrangements identified, two, namely deletions of exon 20 and exons 23-24 of the BRCA1 gene were identified in more than one unrelated families. In addition, the recurrent mutations 5382insC and G1738R, which have been previously identified as founder mutations in the Greek population, were identified in multiple unrelated analyzed families.

CONCLUSIONS: Our results indicate that different large genomic rearrangements account for an important proportion (17%) of the mutations in the BRCA1 and BRCA2 genes, in Greek families at risk of carrying a germline mutation as judged by family / personal history. The use of the available technologies for the identification of such mutational events is therefore necessary when carrying out complete analysis of the genes in high risk families of Greek background.

Citation Format: Angela Apessos, Eirini Papadopoulou, Vassiliki Metaxa-Mariatou, Konstantinos Agiannitopoulos, Christos Markopoulos, Vasileios Venizelos, Grigorios Xepapadakis, Maria Vasilaki-Antonatou, Antonios Keramopoulos, Nikolaos Bredakis, Aristeidis Tsiftsoglou, Georgios Kesisis, Stylianos Kakolyris, Nikolaos Touroutoglou, Ioannis Natsiopoulos, Konstantinos Papazisis, Georgios Nasioulas. Different genomic rearrangements account for 17% of BRCA1/2 mutations in Greece [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-03-08.

Patients with multiple synchronous colonic cancer hepatic metastases benefit from enrolment in a “liver first” approach protocol

AIM: To assess a protocol for treating patients with multiple synchronous colonic cancer liver metastases, which are unresectable in one stage.

METHODS: Patients enrolled in the “liver first” protocol presented with colon-only (not rectal) cancer and multiple synchronous hepatic metastases (type II or III). All patients showed good performance status (ECOG PS 0-1) and were treated with curative intent. Complete oncologic staging including positron emission tomography-computed tomography was performed in order to rule out extrahepatic disease. If bowel obstruction was imminent, an intraluminal colonic stent was placed endoscopically. Subsequently, all patients received standardised neo-adjuvant chemotherapy, that is, FOLFOX or XELOX regimens combined with an antiangiogenic agent (bevacizumab or cetuximab). Provided that a response to chemotherapy was observed, patients underwent either one or two hepatectomies with or without portal vein embolization followed by the indicated colectomy. Further chemotherapy was administered after each procedure. Re-staging was performed after each chemotherapeutic treatment. Disease progression at any stage resulted in discontinuation of the protocol and conversion to palliative disease management.

RESULTS: Prospectively recorded data from 11 consecutive patients (8 men) were analysed for this study. Their mean age at the time of their first assessment was 65.7 (SD ± 15.3) years. Six (54.6%) patients presented with type III metastatic disease. The minimum and maximum follow-up periods were 7.3 and 39.6 mo, respectively. The mean overall survival of all patients was 16.5 (95%CI: 10.0-23.2) mo. A colonic stent had to be placed in 5 (45.5%) patients due to the onset of an intraluminal obstruction. Four (36.4%) patients succeeded in completing all planned surgical operations. Their mean overall survival was 27.2 (95%CI: 15.1-39.3) mo and the mean disease-free survival was 7.7 (95%CI: 3.0-12.5) mo. Patients, who were obliged to shift to palliative treatment due to disease progression, had a mean overall survival of 10.5 (95%CI: 8.6-12.4) mo. None of these patients underwent palliative colectomy. No postoperative mortality was recorded.

CONCLUSION: The implementation of a structured “liver first” approach protocol for the treatment of patients with extensive, liver-limited colon cancer metastatic disease may be beneficial.

Adverse event management in patients with advanced cancer receiving oral everolimus: focus on breast cancer

BACKGROUND

Everolimus, an orally administered rapamycin analogue, inhibits the mammalian target of rapamycin (mTOR), a highly conserved intracellular serine-threonine kinase that is a central node in a network of signaling pathways controlling cellular metabolism, growth, survival, proliferation, angiogenesis, and immune function. Everolimus has demonstrated substantial clinical benefit in randomized, controlled, phase III studies leading to approval for the treatment of advanced renal cell carcinoma, advanced neuroendocrine tumors of pancreatic origin, renal angiomyolipoma and subependymal giant-cell astrocytoma associated with tuberous sclerosis complex, as well as advanced hormone-receptor-positive (HR(+)) and human epidermal growth factor receptor-2-negative advanced breast cancer.

MATERIALS AND METHODS

We discuss clinically relevant everolimus-related adverse events from the phase III studies, including stomatitis, noninfectious pneumonitis, rash, selected metabolic abnormalities, and infections, with focus on appropriate clinical management of these events and specific considerations in patients with breast cancer.

RESULTS

The majority of adverse events experienced during everolimus therapy are of mild to moderate severity. The safety profile and protocols for toxicity management are well established. The class-effect adverse event profile observed with everolimus plus endocrine therapy in breast cancer is (as expected) distinct from that of endocrine therapy alone, but is similar to that observed with everolimus in other solid tumors. Information gained from the experience in other carcinomas on prompt diagnosis and treatments to optimize drug exposure, treatment outcomes, and patients' quality of life also applies to the patient population with advanced breast cancer.

CONCLUSIONS

As with all orally administered agents, education of both physicians and patients in the management of adverse events for patients receiving everolimus is critical to achieving optimal exposure and clinical benefit. Active monitoring for early identification of everolimus-related adverse events combined with aggressive and appropriate intervention should lead to a reduction in the severity and duration of the event.

Development and validation of a prognostic model in patients with metastatic renal cell carcinoma treated with sunitinib: a European collaboration

BACKGROUND

Accurate prediction of outcome for metastatic renal cell carcinoma (mRCC) patients receiving targeted therapy is essential. Most of the available models have been developed in patients treated with cytokines, while most of them are fairly complex, including at least five factors. We developed and externally validated a simple model for overall survival (OS) in mRCC. We also studied the recently validated International Database Consortium (IDC) model in our data sets.

METHODS

The development cohort included 170 mRCC patients treated with sunitinib. The final prognostic model was selected by uni- and multivariate Cox regression analyses. Risk groups were defined by the number of risk factors and by the 25th and 75th percentiles of the model's prognostic index distribution. The model was validated using an independent data set of 266 mRCC patients (validation cohort) treated with the same agent.

RESULTS

Eastern Co-operative Oncology Group (ECOG) performance status (PS), time from diagnosis of RCC and number of metastatic sites were included in the final model. Median OS of patients with 1, 2 and 3 risk factors were: 24.7, 12.8 and 5.9 months, respectively, whereas median OS was not reached for patients with 0 risk factors. Concordance (C) index for internal validation was 0.712, whereas C-index for external validation was 0.634, due to differences in survival especially in poor-risk populations between the two cohorts. Predictive performance of the model was improved after recalibration. Application of the mRCC International Database Consortium (IDC) model resulted in a C-index of 0.574 in the development and 0.576 in the validation cohorts (lower than those recently reported for this model). Predictive ability was also improved after recalibration in this analysis. Risk stratification according to IDC model showed more similar outcomes across the development and validation cohorts compared with our model.

CONCLUSION

Our model provides a simple prognostic tool in mRCC patients treated with a targeted agent. It had similar performance with the IDC model, which, however, produced more consistent survival results across the development and validation cohorts. The predictive ability of both models was lower than that suggested by internal validation (our model) or recent published data (IDC model), due to differences between observed and predicted survival among intermediate and poor-risk patients. Our results highlight the importance of external validation and the need for further refinement of existing prognostic models.

Maximising the duration of disease control in metastatic renal cell carcinoma with targeted agents: an expert agreement

With six targeted agents approved (sorafenib, sunitinib, temsirolimus, bevacizumab [+interferon], everolimus and pazopanib), many patients with metastatic renal cell carcinoma (mRCC) will receive multiple therapies. However, the optimum sequencing approach has not been defined. A group of European experts reviewed available data and shared their clinical experience to compile an expert agreement on the sequential use of targeted agents in mRCC. To date, there are few prospective studies of sequential therapy. The mammalian target of rapamycin (mTOR) inhibitor everolimus was approved for use in patients who failed treatment with inhibitors of vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) based on the results from a Phase III placebo-controlled study; however, until then, the only licensed agents across the spectrum of mRCC were VEGF(R) inhibitors (sorafenib, sunitinib and bevacizumab + interferon), and as such, a large body of evidence has accumulated regarding their use in sequence. Data show that sequential use of VEGF(R) inhibitors may be an effective treatment strategy to achieve prolonged clinical benefit. The optimal place of each targeted agent in the treatment sequence is still unclear, and data from large prospective studies are needed. The Phase III AXIS study of second-line sorafenib vs. axitinib (including post-VEGF(R) inhibitors) has completed, but the data are not yet published; other ongoing studies include the Phase III SWITCH study of sorafenib-sunitinib vs. sunitinib-sorafenib (NCT00732914); the Phase III 404 study of temsirolimus vs. sorafenib post-sunitinib (NCT00474786) and the Phase II RECORD 3 study of sunitinib-everolimus vs. everolimus-sunitinib (NCT00903175). Until additional data are available, consideration of patient response and tolerability to treatment may facilitate current decision-making regarding when to switch and which treatment to switch to in real-life clinical practice.

Abstract 4260: Sunitinib treatment induces Notch expression and activation in renal carcinoma cell lines

Introduction. Notch signaling is an evolutionary conserved pathway that plays a central role in stem cell biology, tumor formation, angiogenesis and cell fate decisions. Currently there is not any clear view as to whether Notch plays an oncogenic role in renal cell cancer (RCC). Notch-1 is activated after cytotoxic stimuli and may induce mTor pathway activation, leading to increased cell survival.

We have investigated the role of Notch expression and activation in RCC cell lines in response to sunitinib treatment and the role of Notch in the activation of the mTor pathway. We elaborated three cell lines with a different VHL and PTEN mutation status: Caki-1 cells (VHL-wt, PTEN-wt), Caki-2 (VHL-mut, PTEN-wt) and 786-O (VHL-mut, PTEN-mut).

Results: When Caki-1 and Caki-2 cells were exposed to sunitinib there was a marked upregulation in the expression of the Notch-1 mRNA and the target transcription factors RUNX1, RBPJ and HES1. The PI3K – mTor – S6K pathway was aslo upregulated. This upregulation was reversed when cells were pre-treated with a gamma-secretase inhibitor. However, both gamma secretase inhibitors and everolimus (an m-Tor inhibitor) had an antagonistic effect when combined with sunitinib (Combination Index &gt;&gt; 1.0). On the other hand, PTEN-mutant 786-O cells have a dysregulated mTor pathway and are more sensitive to inhinition of the m-Tor with everolimus. Sunitinib exposure did not result in further increase of the PI3K-mTor-S6K activation. Interestingly, combination of sunitinib with everolimus was synergistic in 786-O.

Conclusions: VHL-wt and VHL-mutant RCC cells treated with sunitinib activate the Notch pathway. There are reports that Notch plays a tumor suppressor role in RCC and our results are on concert with that. Furthermore, Notch seems to regulate m-Tor pathway activation in cells with a wild-type PTEN.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4260. doi:10.1158/1538-7445.AM2011-4260

Abstract P2-09-18: High VEGFR1 and VEGFR3 Protein Expression Is Associated with Improved Response to the Combination of Paclitaxel (P) and Bevacizumab (Bev) Therapy in Patients with HER2-Negative Metastatic Breast Cancer (MBC)

Background: Treatment with weekly P and 2-weekly Bev has been established as an active 1st line treatment in patients with MBC. However, robust predictive or prognostic biomarkers for this treatment have not been identified as yet.

Patients and Methods: In this retrospective analysis, we evaluated the activity of this combination in patients with HER2-negative MBC. Further, we explored the role of a panel of biomarkers on patients’ outcome. VEGF-A, VEGF-C, VEGFR1, VEGFR2, and VEGFR3 were centrally assessed by immunohistochemistry (IHC) in 70 tissue blocks. P was administered either weekly 90 mg/m2 x12 with 2-weekly Bev 10 µg/kg (86 patients) or 3-weekly 175 mg/m2 x6 with 3-weekly Bev 15µg/kg (38 patients). Bev was administered until progression in the majority of the patients.

Results: The ORR did not differ significantly between the weekly or 3-weekly P schedule (55.8% vs 55.3%). In contrast to the published literature with P monotherapy, median PFS was significantly longer in the 3-weekly compared to the weekly P schedule (20.4 months vs 10.2 months, p=0.029). Median survival has not been reached yet. 2-year survival was 76.1% and 67.3%, respectively (p=0.085). High VEGFR1 and VEGFR3 protein expression, assessed by IHC, was associated with higher response rates (p=0.010 and p=0.039, respectively).

Conclusions: This retrospective analysis confirmed the activity of P and Bev in patients with HER2-negative MBC. Protein expression of VEGFR1 and VEGFR3 was found to be of predictive value. These findings need to be validated in a larger cohort of patients treated with this combination. VEGF polymorphisms (VEGF-2578 and VEGF-1154) are currently assessed in peripheral blood DNA from our patients for possible predictive value.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-18.

Mammosphere culture of metastatic breast cancer cells enriches for tumorigenic breast cancer cells

Introduction

The identification of potential breast cancer stem cells is of importance as the characteristics of stem cells suggest that they are resistant to conventional forms of therapy. Several techniques have been proposed to isolate or enrich for tumorigenic breast cancer stem cells, including (a) culture of cells in non-adherent non-differentiating conditions to form mammospheres and (b) sorting of the cells by their surface phenotype (expression of CD24 and CD44).

Methods

We have cultured metastatic cells found in pleural effusions from breast cancer patients in non-adherent conditions without serum to form mammospheres. Dissociated cells from these mammospheres were used to determine the tumorigenicity of these cultures. Expression of CD24 and CD44 on uncultured cells and mammospheres derived from the pleural effusions was documented.

Results

We found that the majority (20/27) of the pleural effusions tested contained cells capable of forming mammospheres of varying sizes that could be passaged. After dissociation and plating with serum onto adherent dishes, the cells can differentiate, as determined by the increased expression of cytokeratins and MUC1. Analysis of surface expression of CD24 and CD44 on uncultured cells from 21 of the samples showed that the cells from some samples separated into two populations, but some did not. The proportion of cells that could be considered CD44⁺/CD24^low/- was highly variable and did not appear to correlate with the ability to form the larger mammospheres. Of eight pleural effusion mammospheres tested in severe combined immunodeficiency disease (SCID) mice, four were found to induce tumours when only 5,000 or fewer cells were injected, whereas the same number of uncultured cells did not form tumours. The ability to induce tumours appeared to correlate with the ability to produce the larger mammospheres. Uncultured cells from a highly tumorigenic sample (PE14) were uniformly negative for surface expression of both CD24 and CD44.

Conclusion

This paper shows, for the first time, that mammosphere culture of pleural effusions enriches for cells capable of inducing tumours in SCID mice. The data suggest that mammosphere culture of these metastatic cells could provide a highly appropriate model for studying the sensitivity of the tumorigenic 'stem' cells to therapeutic agents and for further characterisation of the tumour-inducing subpopulation of breast cancer cells.

Diorganotin(IV) complexes of dipeptides containing the alpha-aminoisobutyryl residue (Aib): preparation, structural characterization, antibacterial and antiproliferative activities of [(n-Bu)2 Sn(H(-1)L)] (LH=H-Aib-L-Leu-OH, H-Aib-L-Ala-OH)

Two new organotin(IV) complexes with dianionic dipeptides containing the alpha-aminoisobutyryl residue (Aib) as ligands are described. The solid complexes [(n-Bu)(2)Sn(H(-1)L(A))] x 2MeOH (1 x 2MeOH) (L(A)H=H-Aib-L-Leu-OH) and [(n-Bu)(2)Sn(H(-1)L(B))] x MeOH (2 x MeOH) (L(B)H=H-Aib-L-Ala-OH) have been isolated and characterized by single-crystal X-ray crystallography and spectroscopic techniques (H(-1)L(2-) is the dianionic form of the corresponding dipeptide). Complexes 1 x 2MeOH and 2 x MeOH are monomeric with similar molecular structures. The doubly deprotonated dipeptide behaves as a N(amino), N(peptide), O(carboxylate) ligand and binds to the Sn(IV) atom. The five-coordinate metal ion has a distorted trigonal bipyramidal geometry. A different network of intermolecular hydrogen bonds in each compound results in very dissimilar supramolecular features. The IR, far-IR, Raman and (119)Sn NMR data are discussed in terms of the nature of bonding and known structures. The antibacterial and antiproliferative activities as well as the effect of the new compounds on pDNA were examined. Complexes 1 and 2 are active against the gram-positive bacteria Bacillus subtilis and Bacillus cereus. The IC(50) values reveal that the two compounds express promising cytotoxic activity in vitro against a series of cell lines.

The efficacy of somatostatin analogues in the treatment of diabetic retinopathy and thyroid eye disease

Somatostatin, a polypeptide hormone of 14 or 28 aminoacids, is produced by neuroendocrine, inflammatory and immune cells. It has multiple inhibitory functions on the secretion of various hormones and growth factors and modulates several cellular functions. Somatostatin analogues provide an elegant pharmacological principal to modify the high-risk form of proliferative diabetic retinopathy. Pilot investigations have provided evidence that octreotide can very effectively suppress new bleeding and stop visual loss in patients who have failed conventional photocoagulation therapy. In this cohort, octreotide was found to be a safe treatment modality. The same applies also for thyroid eye disease, in which some non-randomized, as well as randomized studies have shown a beneficial effect. More potent analogues, like SOM230, which are not yet in the market, can be proved to have a better therapeutic outcome in such patients and may be considered a safe treatment modality to stop the progression from pre-proliferative to proliferative diabetic retinopathy. This is also true for adolescent patients with thyroid eye disease, as well as for adults who also suffer from diabetes mellitus.

Expression of Syk in invasive breast cancer: correlation to proliferation and invasiveness

BACKGROUND

Spleen tyrosine kinase (Syk) kinase has recently been considered as a tumor suppressor gene in breast cancer.

MATERIALS AND METHODS

Syk expression in patients with invasive breast cancer was immunohistochemically assessed.

RESULTS

Decreased expression was found in 26% of the specimens examined. In cases with vascular invasion, expression of Syk was lost in the intravascular emboli. A significant relationship between increased proliferation levels (as estimated by the proliferative index, Ki67) and decreased Syk expression (p <0.05) was found.

CONCLUSION

Our data suggest that Syk protein expression inversely correlates with the proliferation and invasive capacity of breast cancer.

Cyclin-dependent kinase (CDK) inhibitor olomoucine enhances gamma-irradiation-induced apoptosis and cell cycle arrest in Raji cells

Gamma-irradiation leads to apoptosis and cell cycle arrest in eukaryotic cells. Olomoucine is a novel purine analog acting as a cyclin-dependent kinase inhibitor. The effects of olomoucine in gamma-irradiation mediated cell growth inhibition and apoptosis were studied in the Raji cell line (Burkitt's lymphoma). Gamma-irradiation caused a G2 arrest, increasing the G2/M fragment of the cells. Apoptosis by gamma-irradiation was apparent both by DNA-electrophoresis and PARP-1 cleavage. The combination of olomoucine with irradiation caused an increased G2 arrest and decreased cell survival and DNA synthesis in the non-apoptotic fraction of the remaining cells. Irradiation, as well as olomoucine and the combination of both, induced apoptosis. It seems that olomoucine delays the apoptotic process and inhibits DNA fragmentation, but it decreased survival, cell cycle progression and proliferation of irradiated cells.

Impaired T cell proliferation and zeta chain phosphorylation after stimulation with staphylococcal enterotoxin-B in hemodialysis patients

BACKGROUND

Patients on regular hemodialysis treatment are in an immunodeficiency state. Several studies have shown defective T cell proliferation after stimulation with various agents. Staphylococcal enterotoxin B (SEB) is a MHC-dependent superantigen that triggers proliferation of a large proportion of T cells. T cell activation after stimulation with SEB parallels normal T cell signal transduction. An important and early event in this transduction pathway is the phosphorylation of the zeta chain. In this study, T cell proliferation and zeta chain phosphorylation after stimulation with SEB were evaluated.

METHODS

Peripheral blood mononuclear cells (PBMCs) from 24 patients and 14 healthy individuals were isolated and cultured with or without stimulation with SEB (1 ng/ml). Cell proliferation was estimated by immunoenzymatic measurement of bromodeoxyuridine uptake. PBMCs from 8 patients and 6 healthy individuals were isolated and pulsed for 2 min with or without SEB (10 microg/ml). Zeta chain phosphorylation was estimated by immunoprecipitation and immunoblotting with antiphosphotyrosine antibody.

RESULTS

Lymphocyte proliferation index after SEB stimulation was lower in hemodialyzed patients. Stimulation of T cells with SEB also resulted in a lower zeta chain phosphorylation in hemodialyzed patients.

CONCLUSIONS

Lymphocyte proliferation after MHC-dependent stimulation is impaired in hemodialyzed patients. This proliferation defect is due to impaired zeta chain phosphorylation.