Everolimus plus endocrine therapy beyond CDK4/6 inhibitors progression for HR+ /HER2- advanced breast cancer: a real-world evidence cohort

PURPOSE

Everolimus in combination with endocrine therapy (ET) was formerly approved as 2nd-line therapy in HR(+)/HER2(-) advanced breast cancer (aBC) patients (pts) progressing during or after a non-steroidal aromatase inhibitor (NSAI). Since this approval, the treatment landscape of aBC has changed dramatically, particularly with the arrival of CDK 4-6 inhibitors. Endocrine monotherapy after progression to CDK4/6 inhibitors has shown a limited progression-free survival (PFS), below 3 months. Evidence of the efficacy of everolimus plus ET after CDK4/6 inhibitors is scarce.

METHODS

A retrospective observational study of patients with aBC treated with everolimus and ET beyond CDK4/6-i progression compiled from February 2015 to December 2022 in 4 Spanish hospitals was performed. Clinical and demographic data were collected from medical records. The main objective was to estimate the median progression-free survival (mPFS). Everolimus adverse events (AE) were registered. Quantitative variables were summarized with medians; qualitative variables with proportions and the Kaplan-Meier method were used for survival estimates.

RESULTS

One hundred sixty-one patients received everolimus plus ET (exemestane: 96, fulvestrant: 54, tamoxifen: 10, unknown: 1) after progressing on a CDK4/6 inhibitor. The median follow-up time was 15 months (interquartile range: 1-56 months). The median age at diagnosis was 49 years (range: 35-90 years). The estimated mPFS was 6.0 months (95%CI 5.3-7.8 months). PFS was longer in patients with previous CDK4/6 inhibitor therapy lasting for > 18 months (8.7 months, 95%CI 6.6-11.3 months), in patients w/o visceral metastases (8.0 months, 95%CI 5.8-10.5 months), and chemotherapy-naïve in the metastatic setting (7.2 months, 95%CI 5.9-8.4 months).

CONCLUSION

This retrospective analysis cohort of everolimus plus ET in mBC patients previously treated with a CDK4/6 inhibitor suggests a longer estimated mPFS when compared with the mPFS with ET monotherapy obtained from current randomized clinical data. Everolimus plus ET may be considered as a valid control arm in novel clinical trial designs.

Analysis of the association of HER-2 low carcinomas and PAM50 assay in hormone receptor positive early-stage breast cancer

BACKGROUND

HER2-low has emerged as a new predictive biomarker in metastatic breast cancer. However, its prognostic value in early-stage carcinomas needs to be revisited. We aimed to evaluate the association of HER2-low carcinomas with PAM50 risk groups combined with clinicopathological variables in early breast cancer.

METHODS

We conducted a retrospective analysis of 332 patients with early-stage breast cancer that underwent PAM50 signature analysis between 2015 and 2021at Hospital Universitario 12 de Octubre (Madrid, Spain). Clinical and pathological variables were collected from medical records. After adjusting for potential confounders, we estimated Odds Ratio (OR) and 95% confidence interval for high-risk PAM50 subgroup, comparing HER2-low versus HER2-zero carcinomas by multivariable logistic regression. P values below 0.05 were deemed statistically significant.

RESULTS

192 (57%) patients were classified as HER2-low carcinomas. Median follow-up was 34 months. Adjusted OR for high-risk PAM50 when comparing HER2-low versus HER2-zero carcinomas was 1.31 (95% CI: 0.75-2.30, p = 0.33). The multivariable model detected significant associations for Ki-67% (≥20% vs. <20%: OR = 4.03, 95% CI: 2.15-7.56, p < 0.001), T staging category (T2/T3 vs. T1: OR = 3.44, 95% CI: 1.96-6.04, p < 0.001), progesterone receptor (PR ≥ 20% vs. <20%: OR = 0.44, 95% CI: 0.23-0.83, p = 0.01), nodal staging category (N+ vs. N0: OR = 3.8, 95% CI: 1.89-7.62, p < 0.001) and histological grade (grade 2 vs. 1: OR = 2.41, 95% CI: 1.01-5.73, p = 0.04; grade 3 vs 1: OR = 5.40, 95%CI: 1.98-14.60, p = 0.001).

CONCLUSIONS

In this early-stage breast cancer cohort, HER2-low was not associated with a high-risk PAM50 compared to HER2-zero carcinomas. Ki-67 ≥ 20%, T2/T3, histological grade 2/3, N+ and PR<20% were significantly associated to a high-risk PAM50.

Abstract P5-02-44: Efficacy analysis of CDK4/6 inhibitors in combination with endocrine therapy treatment in HR+/HER2- breast cancer according to PAM50 intrinsic subtype: primary results of SOLTI-1801_CDK-PREDICT study

Background: First-line treatment with cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) plus endocrine therapy (ET) has demonstrated efficacy in improving progression-free survival (PFS), overall response rate (ORR) and, more recently, ribociclib was also improve overall survival (OS) in hormone receptor-positive/HER2-negative (HR+/HER2-) advanced breast cancer (aBC). Unfortunately, most patients eventually progress and develop secondary or primary endocrine resistance. To date, no clinical or molecular markers have shown clinical utility in this setting. However, data from retrospective analysis suggest that intrinsic subtypes (IS) are prognostic and predict benefit from CDK4/6i+ET (Finn SABCS 2017, Prat. JCO 2021). Here, we have evaluated the impact of IS in PFS and ORR.

Methods: This study prospectively evaluated patients with HR+/HER2- aBC treated in the first-line setting with CDK4/6i + ET from February 2015 to January 2022 across 5 hospitals in Spain. Tumor biopsies had been performed within 90 days prior the patient started the CDK4/6i + ET. RNA from FFPE tumors was analyzed at the nCounter® (Nanostring Technologies) using a 72 custom gene panel including the PAM50 genes. The primary objective is to correlate the baseline PAM50 IS with PFS. The Kaplan-Meier method and multivariable cox model PFS analyses were performed adjusting for previous endocrine sensitivity, visceral disease, and metastatic onset disease. Secondary objectives were to estimate the ORR based on RECIST1.1 and its association with IS and the development of a prognostic algorithm that includes clinical and genomic data.

Results: From May 2020 to May 2022, 113 patients with PAM50 results who met all eligibility criteria, including sample quality, were included. IS distribution was 42.5% Luminal A, 46.9% luminal B, 7.1% HER2-enriched, 0.9% basal-like and 2.6% Normal-like (89.4% luminal vs 10.6% non-luminal). Baseline patient characteristics are shown in table 1. The median follow-up for PFS was 18.5 m (interquartile range 10.0 – 31.7m). Median PFS for Luminal vs no-luminal subtypes was 26.8 m (95% CI: 18.9 - 43.8 m) and 10.0 m (95% CI: 5.8 - 26.0 m) (adjusted hazard ratio [aHR]= 2.44 95% IC: 1.17 - 5.07). Median PFS by all IS was not reached (NR) for Luminal A (95% CI: 23.0 – NR); 19.5 m luminal B (95% CI: 15.7 - 27.3 m, aHR vs Luminal A= 1.98 95% IC: 1.09 - 3.62), 10.0 m HER2-E (95% CI: 4.4 - NR, aHR vs Luminal A= 2.75 95% IC: 1.05 - 7.18), 12.4 m Normal-like (95% CI: 5.8 - NR, aHR vs Luminal A= 19.35 95% IC: 2.32 - 160.89) and not estimable for basal-like (aHR vs Luminal A= 5.44 95% IC: 1.44 - 20.60). ORR was not significantly higher in Luminal B (55.1%) and HER2-E (57.1%) subtype versus luminal A (46.3%) (p=0.677). OS follow-up is still immature.

Conclusions: We confirmed the independent prognostic value of the PAM50 IS in first-line HR+/HER2- breast cancer treated with CDK4/6i+ET. Further gene expression analysis and development of a prognostic composite score is ongoing and will be presented at the conference.

This project has received a research grant from “Instituto de Salud Carlos III (ISCIII), Ministerio de Economía y Competitividad” (Spain) awarded within the National Research Program with reference PI 18/01408, co-funded with European Union ERDF funds.

Baseline patient characteristics

Citation Format: Pablo Tolosa, Tomás Pascual, Cristina Hernando, Sonia Servitja, Adela Fernández, Fara Brasó-Maristany, Javier Benitez, Laura Lema, Yolanda Ruano, Lucia Parrilla, Ana María Roncero, Rodrigo Sánchez-Bayona, Manuel Alva, Guillermo Villacampa, María Rocío Moreno-Villa, Jordi Canes, Fernando Salvador, Aleix Prat, Eva Ciruelos. Efficacy analysis of CDK4/6 inhibitors in combination with endocrine therapy treatment in HR+/HER2- breast cancer according to PAM50 intrinsic subtype: primary results of SOLTI-1801_CDK-PREDICT study [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 P5-02-44.

Abstract P3-01-04: A real-world evidence study of everolimus plus endocrine therapy beyond CDK4/6 inhibitors for HR+/HER2- advanced breast cancer

Introduction Since the approval a decade ago of everolimus in combination with endocrine therapy (ET), the treatment landscape of metastatic breast cancer (mBC) has changed dramatically. Endocrine monotherapy after progression to CDK4/6 inhibitors has shown a limited progression-free survival (PFS) below 3 months. Evidence of the efficacy of everolimus plus ET after CDK4/6 inhibitors is scarce. Methods We performed a retrospective observational study of patients with mBC treated with everolimus between September 2011 and April 2022 in 4 Spanish hospitals. Clinical and demographic data were collected from medical records. Our main objective was to estimate the median progression-free survival (mPFS) for everolimus + ET in patients previously treated with a CDK4/6 inhibitor. We also collected the adverse events (AE) related to everolimus. Quantitative variables were summarized with medians (range), and qualitative variables with proportions. We used the Kaplan-Meier method for survival estimates. Results We identified a total of 297 mBC patients treated with everolimus plus ET. The median follow-up time was 20 months (interquartile range: 1 – 97 months). In this cohort, the median age at diagnosis was 49 years (26 – 84 years). At the moment of starting everolimus, the median number of previous lines of treatment was 2 (0 – 12), 22% of patients were ‘de novo’ metastatic, 67% presented visceral involvement, 40% had received previous chemotherapy for advanced disease, and 51% (n=152) had received a previous CDK4/6 inhibitor. The ET combined with everolimus was exemestane (77%), fulvestrant (18%), and tamoxifen (5%). 45% of patients were alive at data cut-off. In patients previously treated with a CDK4/6 inhibitor, the estimated median PFS (mPFS) was 5.9 months (95%CI: 5.0 – 7.8 months). In patients without visceral involvement (n=52), mPFS was 7.2 months (95%CI: 5.5 – 11.0 months), and 5.6 months (95%CI: 3.9 – 7.8 months) in the presence of visceral metastasis (n=100). In patients without previous chemotherapy in the metastatic setting (n=109), mPFS was 7.2 months (95%CI: 5.9 – 8.4 months), and 4.6 months (95%CI: 3.1 – 5.7 months) for patients who had received previous chemotherapy (n=43). For patients without a previous CDK4/6 inhibitor (n=145), the median PFS was 8.3 months (95%CI: 6.4 – 10.3 months). Everolimus starting doses were 10 mg (83%), 5 mg (15%), and 7.5 mg (2%). Dexamethasone mouthwash was used by 44% of patients. The most frequent AE were mucositis (51%; 3% grade 3), anemia (41%; 3% grade 3), hyperglycemia (34%; 2% grade 3), rash (28%; 2% grade 3), neumonitis (21%; 2% grade 3), and diarrhea (17%; 1% grade 3). There were no grade 4-5 adverse events. Dose reduction was made in 35% of patients, and in 16% of patients the treatment was discontinued due to toxicity. Conclusions In our cohort, the use of everolimus plus ET in mBC patients previously treated with a CDK4/6 inhibitor showed a clinically significant benefit in terms of PFS, especially in patients without visceral metastasis, and no previous chemotherapy for advanced disease. In this real-world study, the toxicity profile of everolimus was manageable.

Citation Format: Rodrigo Sánchez-Bayona, Manuel Alva, Alfonso López de sa, Yolanda Jerez Gilarranz, Ana Sánchez de torre, Pablo Tolosa, Alicia de luna, Sara López-Tarruella, Laura Lema, Fernando Moreno, Isabel Echavarria, Ainhoa Madariaga, Javier Benítez, Blanca Herrero, Macarena Rey, Justo Ortega, Salvador Gámez, Andrea Modrego, Rocío Martín Lozano, Luis Figuero-Pérez, Roberto Jiménez, Marta González Sevilla, Irene González, Marianela Bringas Beranek, María de toro, Tatiana Massarrah, María del Monte-Millán, Marina Pinardo, Luis Manso, Coralia Bueno-Muiño, José Ángel García-Sáenz, Miguel Martín, Eva Ciruelos. A real-world evidence study of everolimus plus endocrine therapy beyond CDK4/6 inhibitors for HR+/HER2- advanced breast cancer. [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 P3-01-04.

Abstract OT3-11-02: SOLTI-1910: Predicting olaparib sensitivity in patients with unresectable locally advanced/metastatic HER2-negative breast cancer with BRCA1/2, PALB2, RAD51C/D mutations or HRD by the RAD51 test: RADIOLA TRIAL

Background The OlympiAD trial evaluated the PARP inhibitor (PARPi) olaparib versus a non-platinum standard chemotherapy in HER2-negative metastatic breast cancer (MBC) patients with a germline BRCA1/2 (gBRCA) mutation. Olaparib resulted in improved progression-free survival (PFS) and doubled the response rate vs chemotherapy. Nevertheless, the response rate to PARPi is 60% in the gBRCA1/2 population with MBC (current approval), suggesting a limited positive predictive value of gBRCA1/2 status. Moreover, patients with other relevant Homologous Recombination Repair defects (HRD) such as PALB2 or RAD51C/D mutation carriers, or HRD epigenetic silencing, are not captured with a gBRCA analysis. We have previoulsy shown that the functional HRD biomarker RAD51, tested in FFPE tumor samples using an optimized immunofluorescence-based assay, is associated with platinum response in early TNBC and PARPi response in preclinical BC models. We hypothesize that the RAD51 test would help to expand the clinical benefit of PARPi by predicting response to olaparib in MBC with germline/somatic BRCA1/2, PALB2 or RAD51C/D mutation and beyond. Study design RADIOLA is an open-label, single-arm, multicentre phase II study evaluating treatment with olaparib in male or female ≥18 years patients with HER2-negative MBC with ≤ two prior chemotherapy lines in two cohorts: cohort 1 (N=41) with known germline/somatic BRCA1/2, PALB2 or RAD51C/D mutation; cohort 2 (N=25) with functional HRD, namely RAD51-low score (≤10%), in wild-type/unknown mutation status at study entry. All patients will receive olaparib 300mg po BID until progression or unacceptable toxicity. Primary objective will assess, in terms of overall response rate (ORR), the capacity of the RAD51 score to predict olaparib efficacy in cohort 1. Secondary objectives include PFS, clinical benefit rate, duration of response, safety in both cohorts and ORR in cohort 2. Recruitment Recruitment (11 sites) started in March 2022. As of July 2022, 7 patients have been enrolled in Spain. Funding This study is financially supported by AstraZeneca.

Citation Format: Judith Balmaña, Tomás Pascual, Alba Llop-Guevara, Pablo Tolosa, Isabel Blancas, Maria-Eva Perez-Lopez, Barbara Adamo, Iris Teruel, Jose Ponce, Marta Gonzalez, Gemma Viñas, Laura Lema, Francisco Javier Salvador, Mª Teresa Martinez, Alejandra Espinosa, Aleix Prat, Violeta Serra. SOLTI-1910: Predicting olaparib sensitivity in patients with unresectable locally advanced/metastatic HER2-negative breast cancer with BRCA1/2, PALB2, RAD51C/D mutations or HRD by the RAD51 test: RADIOLA TRIAL [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 OT3-11-02.

Abstract OT2-19-03: Solti-1801. Analysis of the efficacy of CDK4/6 inhibitors in combination with hormonal treatment in luminal breast cancer in relation to the intrinsic subtype and markers of immunity (CDK-predict)

Introduction. The incorporation of cyclin-dependent kinase inhibitors 4 and 6 (CDK4/6 inhibitors) with endocrine therapy in patients with hormone receptor-positive/HER2-negative (HR+/HER2-) advanced breast cancer has demonstrated its efficacy improving progression-free survival (PFS), overall response rate (ORR) and, more recently, overall survival (OS). However, patients eventually progress due to resistance to treatment. To date, no clinical or molecular markers defining the HR+/HER2- patient population that obtains the greatest benefit from these drugs have been found, apart from estrogen receptor positivity. However, data from multiple retrospective analysis suggest that within HR+/HER2- disease, the non-luminal intrinsic subtypes (20-30% of these patients) have a worse prognosis and may not benefit equally from every CDK4/6 inhibitor (Finn SABCS 2017, Prat. JCO 2021). Furthermore, the prognostic impact of tumor infiltrating lymphocytes (TILs) and gene expression related to the immune response in the context of HR+/HER2- advanced breast cancer have not been deeply investigated. Design. CDK-PREDICT is an observational, non-interventional, multicenter study that will include 114 patients with advanced breast cancer treated in first-line with CDK4/6 inhibitors + hormone therapy. The primary objective is to correlate the baseline intrinsic subtypes (defined by PAM50) with the efficacy (measured as PFS) of CDK4/6 inhibitors + hormone therapy. As secondary objectives, the correlation of the intrinsic subtypes with ORR and with the histopathological characteristics of the tumor will be analyzed. In addition, the expression of immune response and cell cycle genes, as well as the presence of TILs, will be correlated with the intrinsic subtypes and with PFS and ORR. Formalin-fixed paraffin-embedded (FFPE) tumor tissue samples will be hematoxylin and eosin (H&E) stained and percentage of TILs will be determined. RNA will be purified and analyzed at the nCounter (Nanostring Technologies) using a panel of 72 genes including the PAM50 genes and immune genes such as PD1, PDL1, CD8 or CD4. Overall, we aim to develop a predictive score combining clinical, genomic, and immune expression data integrating tumor biology and microenvironment. For inclusion in the study, a metastatic sample taken within 100 days prior to CDK4/6 inhibitors treatment is required. Once this sample has been collected, registered, and assessed for quality, patients will be followed up every 6 months until disease progression, death or withdrawal from the study. As of July 2021, 80 patients have been included at 5 sites in Spain. This study is included within the Biomarker program of SOLTI. Recruitment of this study started in June 2020. Acknowledgements.This project has received a research grant from “Instituto de Salud Carlos III (ISCIII), Ministerio de Economía y Competitividad” (Spain) awarded within the National Research Program with reference PI 18/01408, co-funded with European Union ERDF funds (European Regional Development Fund).

Citation Format: Pablo Tolosa, Tomás Pascual, Cristina Hernando, Sonia Servitja, María Fernández Abad, Fara Brasó-Maristany, Javier Benítez, Laura Lema, Mario Martínez, Yolanda Ruano, Lucía Parrilla, Alejandra Bernardini, Ana María Roncero, Laia Paré, Jordi Canes, Patricia Villagrasa, Fernando Salvador, Aleix Prat, Eva Ciruelos. Solti-1801. Analysis of the efficacy of CDK4/6 inhibitors in combination with hormonal treatment in luminal breast cancer in relation to the intrinsic subtype and markers of immunity (CDK-predict) [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 OT2-19-03.

Abstract P5-13-24: Efficacy of first line CDK4/6 inhibitors in HER2-low vs HER2-zero, hormone receptor positive, HER2 negative metastatic breast cancer

Introduction: CDK4/6 inhibitors are the standard of care in the vast majority of patients with metastatic breast cancer (MBC) in first line setting. HER2-low expression, defined as IHC score of 1+ or 2+ with negative ISH assay, has been associated with resistance to CDK4/6 inhibitors. This has not yet been explored for advanced disease in the first line setting. We aimed to analyze the efficacy of CDK4/6 inhibitors in this subset of patients compared to HER2-zero tumors. Methods: We identified patients with positive hormone receptors and HER2 negative metastatic breast cancer treated with first line CDK4/6 inhibitor (palbociclib, ribociclib or abemaciclib) and letrozole or fulvestrant between December 2017 - April 2021 in our institution (Hospital 12 de Octubre, Madrid, Spain). HER2 expression and PAM50 subtypes were analyzed in metastatic tissue samples for all patients. For the analysis, patients were classified as HER2-zero or HER2-low groups. Our main objective was to evaluate the relationship between HER2 expression and progression-free survival (PFS) with log-rank test. Multivariable Cox regression model was used to estimate the adjusted hazard ratio (HR). As secondary objectives, we analyzed this association in all CDK4/6 subgroups and described the prevalence of PAM-50 subtypes in each category (HER2-low and HER2-zero). Results: We included 82 patients in our final analysis. 57% of the patients were classified in the HER2-low category. In our sample, 49% of patients received palbociclib, 39% ribociclib and 12% abemaciclib. A high proportion of patients presented visceral disease (75% in the HER2-zero vs 60% in the HER2-low group). Only 20% of tumors were considered as hormone-resistant. The overall response rate was slightly higher in the HER2-zero category (41% vs 35% in the HER2-low). With a median follow-up of 14 months (2 - 48 months), the median PFS was 31.7 months (95%CI: 20.3 - NR months) in the HER2-zero category and 22.8 months (95%CI: 15.7 - NR months) in the HER2-low (p=0.37). In the multivariable Cox regression model, HER2-low tumors were associated with a non-significantly higher risk of progression (HR=1.62; CI 95%:0.74-3.54). In patients treated with palbociclib, the median PFS for HER2-zero vs HER2-low categories were 31.7 months and NR (p=0.79), respectively. For ribociclib, the HER2-zero had a median PFS of 38.4 months and 33.1 months in the HER2-low category (p=0.47). In patients treated with abemaciclib, median PFS was NR for HER2-zero group and 9.2 months for HER2-low (p=0.18). The interaction test between HER2 categories and CDK4/6 inhibitors was not statistically significant (p=0.48). PAM-50 subtypes information was available for 47 patients. In these patients the prevalence of PAM-50 subtypes showed a relative higher proportion of luminal subtypes in the HER2-zero category (95%) and non-luminal (HER2-enriched and normal-like subtypes) in the HER2-low category (21%). Conclusions: In our sample, HER2-low category had a shorter median PFS in first line treatment with CDK4/6 inhibitors plus endocrine treatment compared to HER2-zero group. This finding was consistent for the three CDK4/6 inhibitors analyzed, although the HER2-low group showed more relative benefit in terms of PFS with palbociclib. Our results suggest a lower benefit of CDK4/6 inhibitors in the first line treatment of HER2-low MBC, which could be partially explained by a relative higher proportion of non-luminal PAM-50 subtypes in HER2-low tumors. FundingThis project has received a research grant from “Instituto de Salud Carlos III (ISCIII), Ministerio de Economía y Competitividad” (Spain) awarded within the National Research Program with reference PI 18/01408, co-funded with European Union ERDF funds (European Regional Development Fund).

Citation Format: Rodrigo Sanchez-Bayona, Santiago Terán, Ana Sánchez De Torre, Manuel Alva, Laura Lema, Luis Manso, Estefanía Toledo, Ana Maria Roncero, Cristina Merino, Mario Martínez, Lucía Parrilla, Eva Ciruelos, Pablo Tolosa. Efficacy of first line CDK4/6 inhibitors in HER2-low vs HER2-zero, hormone receptor positive, HER2 negative metastatic breast cancer [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 P5-13-24.

AB0342 OBSTETRIC AND THROMBOTIC ANTIPHOSPHOLIPID SYNDROME: ARE THEY DIFFERENT ENTITIES?

Background:

Several studies showed two main clinical phenotypes of antiphospholipid syndrome (APS): thrombotic (TAPS) and obstetric APS (OAPS). Although they have the same autoantibody profile, one of them developed thrombosis and other one obstetric morbidity.

Objectives:

To study clinical, demographic and antibody profile in patients with TAPS and OAPS.

Methods:

we retrospectively evaluated TAPS and OAPS patients who were included in Argentine Antiphospholipid antibodies registry. We studied clinical, demographic and antibody profile in both groups.

Results:

238 patients were included in the registry. 201 (84.81%) of them were female. 122 (60.69 %) of them fullfilled APS Sydney classification criteria, 47 (38.52%) TAPS and 52 (42.62%) OAPS. 23 (18.85%) patients had both thrombotic and obstetric events so they were excluded in this analysis.

Arterial Hypertension (HBP) and Hyperlipidemia were more frequent in TAPS versus OAPS. Older age was found in TAPS as well as in association with Systemic lupus erythematosus (SLE). There was no difference in antibody profile between the 2 groups, and the Global Antiphospholipid Syndrome Score (aGAPSS) was higher in TAPS than OAPS.

18 (38.3%) of TAPS patients had at least 1 pregnancy. Mean number of pregnancies of TAPS was 2.5 (1.10) and 3.84 (1.86) in OAPS. Thrombotic events were not found in TAPS during pregnancy and puerperium. HBP and gestational diabetes (GD) and other pregnancy related comorbidities were found in TAPS.

OAPS (n=52)TAPS (n=47)POAPS(n=52)TAPS(n=18)SLE, n (%)11 (21.2)28 (59.6)0.0002N% (DE)N % (DE)aGAPSS, mean (RIQ)4 (5)8 (5)<0.0001Abortions (<10 weeks)3338.4 (36.2)826.5 (35.3)Age, mean (DE)39.3 (6.24)43.1 (13.5)<0.0001Live Birth3633.5 (28.1)1672.2 (34.7)HBP, n (%)5 (9.6)15 (31.9)0.0121 >37 weeks2116.4 (2.38)1661.1 (31.7)Hyperlipidemia, n (%)4 (7.7)12(25.5)0.0267Prematurity <37 >34 weeks118.76 (1.97)0-GD, n (%)3(5.8)2(4.3)0.9999Prematurity <34 weeks96.37 (1.49)11.39 (5.89)Obesity, n (%)8 (15.4)4 (8.5)0.2912Pre eclampsia >34-<37 weeks10.490 (0.0350)24.63 (0.138)Smoking, n (%)11 (21.1)13 (27.6)0.4019Placental Hematoma31.86 (8.18)12.78 (11.8)Sedentary lifestyle, n (%)16 (30.8)17 (36.2)0.8486Abruptio Placentae21.96 (9.80)24.17 (12.9)Triple Positivity59.648.50.8323 Normal delivery2017.8 (27.9)1447.7 (33.9)Double Positivity11.936.4Cesarean section2217.2 (21.6)211.1 (32.3)Simple Positivity2938.51940.4Urgent Cesarean section139.80 (20.3)412.5 (24.6)GD21.37 (7.49)12.78 (11.8)HBP63.46 (10.3)310.2 (26.3)

Conclusion:

Antibody profile was similar in TAPS and OAPS. However, clinical manifestations and cardiovascular risk were different. These results should be evaluated in prospective studies.

Disclosure of Interests:

None declared

Efficacy and safety of weekly paclitaxel in elderly patients with heavily pretreated platinum-resistant ovarian carcinoma

e17552

Background: In platinum-resistant ovarian cancer treatment, single-agent paclitaxel can be used alone or in combination with bevacizumab. We aimed to assess the efficacy and safety profile of a weekly paclitaxel (WP) scheme in heavily pretreated platinum-resistant high-grade serous ovarian carcinoma. Methods: We retrospectively analyzed 30 adult patients with platinum-resistant high-grade serous ovarian carcinoma treated with WP at our institution between 2015 and 2020. Patients with platinum-resistant ovarian, fallopian tube or primary carcinoma of the peritoneum who had received at least 3 doses of WP (80 mg/m2) alone or in combination with bevacizumab until disease progression or unacceptable toxicity were included in the analysis. Progression-free survival was assessed according to the Response Evaluation Criteria in Solid Tumors version 1.1. Information about toxicity was gathered from medical reports and lab tests. Kaplan-Meier curves and Log-rank test were performed for survival estimates. Results: In our sample, the median age was 68 years (IQR: 60-75) and the median number of previous lines of systemic treatment was 3 (range 1-5). 40% of patients received WP in combination with bevacizumab. The disease control rate was 60.7% (42.9% partial response and 17.8% stable disease). In the overall analysis, the median progression-free survival (mPFS) was 5.0 months (95% CI: 2.0-7.1 months). The presence of ascites significantly shortened the mPFS compared to patients without it (1.1 vs 5.1 months, p < 0.001). Even though the addition of bevacizumab to WP improved the mPFS, the difference was not statistically significant compared to WP alone (7.1 vs 4.06 months, p=0.30). Peripheral neuropathy was the most common adverse event (78% all grades, 18% grade 3). No grade 3 hematologic toxicity was registered. Treatment was discontinued in 6 patients (20%) – 4 due to peripheral neuropathy and two because of toxicoderma. Conclusions: In our sample, WP was an active and safe regimen in heavily pretreated platinum-resistant ovarian carcinoma. WP was well tolerated in elderly patients. The presence of ascites was associated to a shorter PFS in patients treated with WP compared to ascites-free patients.

Abstract OT-26-04: Solti-1801. Analysis of the efficacy of CDK4/6 inhibitors in combination with hormonal treatment in luminal breast cancer in relation to the intrinsic subtype and markers of immunity (CDK-PREDICT)

Introduction. The incorporation of cyclin-dependent kinase inhibitors 4 and 6 (CDK4/6 inhibitors) with endocrine therapy in patients with advanced hormone receptor-positive (HR+) breast cancer and without overexpression of the HER2 (HER2-) oncogene has demonstrated its efficacy improving progression-free survival (PFS), overall response rate (ORR) and, more recently, overall survival (OS). However, patients eventually progress due to resistance to treatment. To date, no clinical or molecular markers defining the HR +/HER2- patient population that obtains the greatest benefit from these drugs have been found, apart from estrogen receptor positivity. However, there are data from multiple retrospective analysis suggesting that within HR+/ HER2- disease, the non-luminal intrinsic subtypes (20-30% of these patients) have a worse prognosis and may not benefit from CDK4/6 inhibitors. Furthermore, the prognostic impact of tumor infiltrating lymphocytes (TILs) and gene expression related to the immune response in the context of HR + / HER2- advanced breast cancer have not been deeply investigated.

Design. CDK-PREDICT is an observational, non-interventional, multicenter study that will include 114 patients with advanced breast cancer who have received, are receiving or are going to receive endocrine therapy plus a CDK4/6 inhibitor for, at least, 8 weeks as first-line treatment. The primary objective is to correlate the intrinsic subtypes (defined by PAM50) with the efficacy (measured as PFS) of CDK4/6 inhibitors + hormone therapy. As secondary objectives, the correlation of the intrinsic subtypes with ORR and with the histopathological characteristics of the tumor will be analyzed. In addition, the expression of immune response and cell cycle genes, as well as the presence of TILs, will be correlated with the intrinsic subtypes and with PFS and ORR. Overall, we aim to develop a predictive score combining clinical, genomic and immune expression data integrating tumor biology and microenvironment. For inclusion in the study, a metastatic sample taken within 90 days prior to CDK4/6 inhibitors treatment will be required. Once this sample has been collected, registered and assessed for quality, patients will be followed up every 6 months until disease progression, death or withdrawal from the study.

This project has received a research grant from “Instituto de Salud Carlos III (ISCIII), Ministerio de Economía y Competitividad” (Spain) awarded within the National Research Program with reference PI 18/01408, co-funded with European Union ERDF funds (European Regional Development Fund). This study is included within the Biomarker program of SOLTI. Recruitment of this study started in June 2020.

Citation Format: Pablo Tolosa, Tomás Pascual, Cristina Hernando, Sonia Servitja, María Fernández Abad, Rafael Villanueva, Fernando Henao, Javier Benítez, Laura Lema, Mario Martínez, Yolanda Ruano, Lucía Parrilla, Alejandra Bernardini, Ana María Roncero, Laia Paré, Jordi Canes, Fernando Salvador, Patricia Villagrasa, Aleix Prat, Eva Ciruelos. Solti-1801. Analysis of the efficacy of CDK4/6 inhibitors in combination with hormonal treatment in luminal breast cancer in relation to the intrinsic subtype and markers of immunity (CDK-PREDICT) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-26-04.

Abstract PO-020: Impact of CDK 4/6i withdrawal or dose adjustment on COVID-19 incidence in HR+/HER2- mBC patients during the pandemic

Background: On January 30th, 2020, the World Health Organization (WHO) declared public health emergencies of international concern (PHEIC) because of the outbreak of SARS-CoV2 and coronavirus disease 2019 (COVID-19). It has rapidly expanded all around the world, highlighting Madrid as one of the cities with a highest incidence. Oncologists have had to adapt treatments in order to reduce the pandemic impact. CDK4/6 inhibitors (CDK4/6i) in combination with hormone therapy are the standard of care in hormone receptor-positive (HR+), HER2-negative (HER2-) metastatic breast cancer (mBC) patients (P). Asymptomatic neutrophil count decrease is the most frequent toxicity of these agents and may negatively impact on incidence and severity of COVID-19 disease.

Methods: Hospitalized P increased exponentially from 10 to 16 March 2020 in our hospital. 78 P diagnosed with ER+/HER2- mBC were on CDK4/6i treatment at that time. At the physicians’ discretion CDK4/6i withdrawal or dose adjustment was performed (considering age, comorbidities, and presence of previous neutropenia). The presence of risk factors such as advanced age or previous neutropenia were key issues when deciding to withdraw or adjust CDK4/6i. We conducted a retrospective analysis to evaluate this decision. All P were selected, and data were collected on May 15th, 2020. The main end point was to evaluate the impact of CDK4/6i withdrawal or dose adjustment (non-exposed) on the incidence of COVID-19 defined as high clinical suspicion (including anosmia) or positive PCR; we estimate the odds ratio (OR) through logistic regression. As secondary objectives P characteristics were evaluated to identify and control potential confounding factors, we also calculate adjusted OR by multivariate analysis.

Results: A total of 78 P were evaluated, 44 P treated with palbociclib, 21 with ribociclib, and 13 with abemaciclib in combination with hormonal therapies. Incidence of COVID-19 was 7.7% (6/78 P), 12.8% (5/39) in exposed P, and 2.7% (1/39) in non-exposed P. The OR for exposed patients was 5.8 IC 95% (0.62 to 50.25) p 0,077. Age over 65 years and bone-only disease were associated with a lower COVID 19 relative risk, while diabetes mellitus was associated with a higher incidence. None of the 25 patients over age 70 were infected. In multivariate analysis the adjusted OR for exposed P was 7.68 (p 0.24). Incidence of COVID-19 was numerically higher in patients treated with ribociclib (14.29%) compared to palbociclib (4.55%) or abemaciclib (7.69%). No risk of progression disease was observed in P who had CDK 4/6i withdrawn or dose reduction (p 0.98).

Conclusions: Despite the lack of statistical significance, CDK4/6i withdrawn or dose reduction may reduce the incidence of COVID-19. Greater collection of data during COVID-19 pandemic is needed and will provide us with strong evidence to make decisions in case of new outbreaks.

Citation Format: Pablo Tolosa, Ana Sanchez-Torre, Helena Bote de Cabo, Rodrigo Sánchez-Bayona, Mercedes Herrera, Ramón Yarza, Laura Lema, Luis Manso, Eva Ciruelos. Impact of CDK 4/6i withdrawal or dose adjustment on COVID-19 incidence in HR+/HER2- mBC patients during the pandemic [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr PO-020.

Aflibercept (Z) in combination with FOLFIRI for second-line treatment of patients (pts) with metastatic colorectal cancer (mCRC): Safety and quality of life (QoL) data from the Spanish subgroup of the Aflibercept Safety and Quality-of-Life Program (ASQoP)

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Background: In the VELOUR trial, adding Z to FOLFIRI improves OS, PFS and RR in mCRC pts progressing after oxaliplatin ±biologic agents. The ASQoP trial (NCT01571284) was designed to gather safety and QoL data from mCRC in real-life setting. We report data collected by the Spanish investigators. Methods: ASQoP is single-arm, open-label trial evaluating safety and QoL of Z in mCRC pts as 2nd line. Eligible pts received Z (4mg/kg) q2wks on day 1/cycle, followed by FOLFIRI (dosing was at physician’s discretion) until disease progression, unacceptable toxicity, death, or investigator/pt decision. The EQ-5D was used for utility index (UI) measure and the EORTC QLQ-C30 as generic cancer instrument. QoL population consisted of pts completing the questionnaire at baseline and ≥1 assessment post-baseline and received ≥1 part of 1 dose of study treatment. Results: The safety population comprised 77 pts with ≥1 completed cycle of treatment. Grade (G)3/4 AEs were reported in 72.7% of pts (vs 83.5% in VELOUR), being G3 most commonly reported. There was no G4 hypertension, stomatitis, or proteinuria. G4 Diarrhea was found in 1.3% of pts. Mean baseline UI was 0.7 (95% CI, 0.63-0.78) in 51 pts, and remained relatively stable at cycles 3 (n=39) and 7 (n=24), with a mean (±SD) change from baseline of 0.03 (±0.26) and -0.06 (±0.35), respectively. Mean baseline global health status score was 63.1 (95% CI, 55.8-70.4) in 54 pts, and remained stable up to cycle 9 with a mean (±SD) change from baseline of 4.17 (±38). Conclusions: Thisanalysis has identified no new safety signals and suggests an acceptable toxicity profile with a relatively stable UI and QoL in Spanish mCRC pts in the real-life setting. [Table: see text]

Abstract 1539: Analysis of differential protein profiles in co-culture models of pancreatic cancer cells and fibroblasts

Background: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal human malignancies. The vast majority of patients with advanced disease die within a year of diagnosis.

Tumor microenvironment plays a critical role in tumor initiation, progression, metastasis, and response to treatment in PDAC. Pancreatic adenocarcinoma cells often appear to grow within a fibrotic, abundant, and poorly perfused stroma, with epithelial cells frequently accounting for &lt;20% of the tumor volume. Cellular components of tumor stroma include fibroblasts, macrophages, and stellate cells plus extracellular proteins. Moreover, the network of tumor stroma imposes a barrier for drug delivery.

The aim of this study was to search for novel protein biomarkers of tumor-stroma interaction for a better understanding and intervention of PDAC.

Methods: 1- Co-cultures between two pancreatic adenocarcinoma cell lines (PL45 and Capan-1) and embryonic fibroblasts (LC5) were established. LC5 cell line was stably transfected with Green Fluorescent Protein (GFP) to allow their detection, and later separation by flow cytometry, of the co-cultures. 2- In addition, tumor cells were grown with fibroblasts secretome. 3- After 72 hours of co-culture, tumor cells were isolated and protein extraction was performed. 4- Proteins differentially expressed in tumor cells grown in co-cultures, or in tumor cells grown with fibroblasts secretome, versus in tumor cells monocultures, were identified by using two-dimensional electrophoresis-based proteomic tools (2D-DIGE) followed by mass spectrometry (MS/MS) of the spots of interest.

Results: A total of 105 differentially expressed proteins were documented between PL45 cells growing in mono-culture, co-culture and conditioned medium. Also, 161 differentially expressed proteins were recognized under similar conditions in the Capan1 cell line.

Our study identified seventeen different proteins mainly involved in cytoskeleton organization (Filamin B, Alpha-actinin-4, Annexin A2, Radixin, T-complex protein 1 subunit epsilon, Actin cytoplasmic 1); regulation of cell migration and adhesion (Prelamin-A/C, 40S ribosomal protein SA); protein biosynthesis (EF-2); DNA damage and repair response (VCP, XRCC6); nucleotide biosynthetic process (MTHFD1) and, heat-stress response (HSPD1, GRP78, STIP1, CCT5, Stress-70 protein mitochondrial).

Conclusion: This in vitro model identifies several processes that might be responsible for the tumor-stromal interactions occurring in vivo, which should be considered potential targets for therapeutic interventions in PDAC, in addition to those targets already known to exist in PDAC cells.

Citation Format: Elena Prieto-García, M. Teresa Agulló-Ortuño, C. Vanesa Díaz-García, Inés García-Consuegra, Jorge Adeva, M. Carmen Riesco, Lucía Parrilla, Carlos Gómez, Laura Lema, Luis Robles, Hernán Cortés-Funes, José A. López-Martín. Analysis of differential protein profiles in co-culture models of pancreatic cancer cells and fibroblasts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1539. doi:10.1158/1538-7445.AM2015-1539

Association between inflammatory markers and prognosis in resected pancreatic cancer (PC)

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Background: Inflammatory markers like the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) or fibrinogen (F) and nutritional markers like albumin (alb) have a prognostic value in different types of cancer. However, the paucity of data in pancreatic cancer (PC) keeps their role in this setting unclear. We aimed to determine whether NLR, PLR, F and alb may be prognostic factors in resectable PC. Methods: Demographic, histologic and serologic characteristics (pre and postoperative blood counts) of 77 consecutive PC patients (pts),who underwent curative surgery at our centre between January 2003 and December 2013,were retrospectively collected. We investigated the association of presurgical NLR, PLR, F and alb with overall survival (OS) and disease free survival (DFS) and analyzed the impact of their kinetics after surgery on the outcomes. Results: main pts characteristics are showed in Table. Median OS and DFS were 23 months (m), (95% CI 13.4-32.5) and 10 m (95% CI 7.4 - 12.6) respectively. Pts with NLR < 5 had a significant improvement in OS compared to those with NLR > 5 (29 m vs.16 m, log rank p <0.05 ). F values < 450 mg/dl were also associated with increased OS (30 vs. 16 m, log rank p=0.032). After adjusting by the Cox regression model, only NLR remained an independent prognostic factor for OS (HR, 1.6; p<0.05). PLR (grouped in 3 cutoffs: < 150, 150-300 and >300) and alb (<2, 2-3.5, >3.5 mg/dl) were not associated with significant differences in outcomes. Pre and postoperative values were compared. No association was found between a drop on NLR to <5 after surgery and OS or DFS. Conclusions: our results support that NLR could be a prognostic factor in PC pts undergoing surgery. Changes in NLR due to surgery do not seem to impact the outcome. PLR, F and alb did not correlate with prognosis. [Table: see text]

Phase II study of preoperative bevacizumab, capecitabine, and radiotherapy for resectable locally advanced rectal cancer

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Background: Bevacizumab into chemoradiotherapy appears safe and active in locally advanced rectal cancer (LARC).This study evaluates whether the addition of bevacizumab to capecitabine-based chemoradiotherapy in the preoperative treatment of LARC improves pathological complete response rate (pCR).

Methods: Open-label, unicentric, phase II study in patients with resectable LARC (stage II or III), with or without nodal involvement and no evidence of distant metastases. Treatment schedule of 4-cycles: bevacizumab administered iv on day 1 (10 mg/kg in the first cycle and 5 mg/kg in the following 3 cycles) and capecitabine (900mg/m2/bid) in the 2nd cycle (5 d/wk) concomitantly with radiotherapy 45Gy (25 fractions of 1.8Gy/day) over 5 weeks. Surgical resection was scheduled 6-8 weeks after therapy completion. Preliminary results from ITT analysis are presented.

Results: Of the 43 patients included, 41 comprised ITT population. Baseline characteristics: median age 63 (55-67) years; male 76%; ECOG 0/1 49%/51%; stage T3/N1 80.5%/58.5%; nodal metastases 85%. 39 patients underwent surgery, 9 abdominoperineal and 30 anterior resection. No evidence of metastasis after surgery in 97%. Total mesorectal excision was performed in 69% of patients and 85% underwent R0 resection. Sphincter-preservation was achieved in 79.5%. Downstaging occurred in 82%. Among 39 patients evaluable for pathological response, 7.7% experienced pCR, 69.2% partial response and 20.5% stable disease. Grade 3/4 toxicities: 9.8% lymphopenia (all related to capecitabine and 4.9% to bevacizumab), 2.4% neutropenia (capecitabine-related), 2.4% radiodermatitis (related to RT and capecitabine) and 2.4% vasospastic angina (bevacizumab and capecitabine-related). 13 patients had postoperative complications not treatment-related. The most common were wound infection (6), intra-abdominal collection (3), wound dehiscence (2) and paralytic ileus (2).

Conclusions: Preoperative regimen with bevacizumab, capecitabine and RT is active for LARC with promising results of R0 resection, sphincter- preservation and tumour downstaging as well as manageable toxicity. Further studies are ongoing to confirm these data.

No significant financial relationships to disclose.

Excision repair cross-complementing 1 (ERCC1) and survival in advanced bladder cancer: Confirmatory results using immunohistochemistry

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Background: DNA damaging agents are the backbone of combination chemotherapy regimens for the treatment of advanced bladder cancer. We hypothesized that levels of DNA repair genes such as ERCC1 could predict survival in patients receiving platinum based therapy. Our previous work (Bellmunt J et al, Ann Oncol. 2007) showed that survival was significantly higher in advanced bladder cancer patients with low gene expression levels of ERCC1 measured by RT-qPCR (25.4 versus 15.4 months; p = 0.03). We aimed to confirm these findings using immunohistochemistry (IHC) in an independent cohort of advanced bladder cancer patients treated with cisplatin-based chemotherapy at our institution. Methods: Formalin-fixed paraffin-embedded tumor tissue was available from 51 patients. IHC stains for ERCC1 protein levels were scored as percentage and intensity of positive cells. ERCC1 staining was considered positive if detected in ≥1% tumor cells. The Kaplan-Meier method was used to calculate survival and the Cox proportional hazards model was used to examine the prognostic value of protein expression levels. Results: ERCC1 staining was negative in 60% of patients, weakly positive (1–10% positive cells) in 21% and strongly positive (>10% positive cells) in 19%. Median overall survival for all patients was 14.4m (95% CI 6.7–16.1m). Median disease-specific survival was significantly higher in patients negative for ERCC1 by IHC (12.6m versus 8.6m; p = 0.032). Conclusions: Our results using the more simple IHC technique confirm the prognostic value of ERCC1 expression in advanced bladder cancer. Patients with high expression of ERCC1 by IHC have a worse disease-specific survival than patients with no expression. A correlative study of IHC and RT-qPCR in both sets of samples is ongoing.

No significant financial relationships to disclose.

MET in small cell lung carcinoma (SCLC): Effects of a MET inhibitor in SCLC cell lines and prognostic role of MET status in patients

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Purpose: HGF/MET pathway is aberrantly activated by receptor overexpression and mutations in SCLC preclinical models, enhancing their oncogenicity. The significance of MET expression in SCLC remains unclear. Our aim was to analyze the effects of MET inhibition in chemosensitive/refractory SCLC models and to study the expression pattern and prognostic impact of total and phosphorylated (p) MET in SCLC patients. Methods: Total and p-MET expression (Western Blot), gene copy number (FISH), and exon 14 activating mutations (sequencing) were evaluated in H69 and H69AR SCLC cell lines. PHA-665752 (PHA), alone or combined with doxorubicin, was used to study the effects of pathway inhibition on viability, colony formation and invasion assays in basal/stimulated conditions (HGF). Fifty-eight SCLC cases were evaluated for MET and p-MET expression by immunohistochemistry. Survival analyses were performed. Results: H69 and H69AR (both R988C mutated) expressed MET at basal conditions, but not p-MET. HGF induced MET phosphorylation, increased proliferation (20%) and protected cells from doxorubicin cytotoxicity. PHA 0.5μM blocked MET phosphorylation, decreased colony formation by 50% in H69, counteracted the cytoprotective effect of HGF and inhibited invasion in H69AR. MET expression was found in 98% normal bronchial epithelia, and 78% tumor samples (overexpression 38%). Activated MET was focally detected in normal and metaplastic mucosa and expressed in 22% tumors. MET expression was associated with improved overall and disease free survival (p: 0.06 and 0.051, respectively). All p-MET positive cases within MET expressing tumors, showed relapsed disease (83% in negative p-MET samples, p=0.065), suggesting MET activation may revert the good prognosis linked to total MET expression. Conclusions: MET activation, results in a more aggressive phenotype in SCLC cells. PHA at MET inhibiting concentrations reverses this phenotype. In SCLC specimens, MET expression was more prevalent than p-MET and associated with raised prognosis. All these data suggest that studies with MET inhibitors should focus on p-MET positive SCLC.

[Table: see text]

Dihydropyrimidine dehydrogenases (DPYD), and cytidine-deaminase (CDA) gene polymorphisms as genomic predictors of clinical outcome in resected gastric cancer patients (GCP) treated with fluoropyrimidine-based adjuvant chemotherapy

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Background: Single nucleotide polymorphisms (SNPs) of DPYD gene induces DPD deficiency resulting in decreased activity of 5-fluorouracil derivatives in treatment of colorectal cancer patients (pts). In GCP has not been previously analysed. Methods: We analysed paraffin-embedded biopsies from 50 consecutive resected GCP who received adjuvant chemotherapy with four cycles of Mitomycin C (MMC), 20 mg/m2 iv day 1 plus oral Tegafur (TG), 500 mg/m2 day 1 to day 45 every six weeks, for SNPs of genes DPYD1 (A/G; Ile/Val), DPYD2 (C/T; Arg/Cys) and CDA (A/C; Lys/Gin). The status of alleles (wild type or at least 1 polymorphism) was correlated with outcome, overall survival (OS) and toxicity. Results: The status of SNPs frequencies according to the classification between wild type/non-wild type, were 36/14 in DPYD1; 26/24 in DPYD2; and 17/23 in CDA or between homozygous/heterozygous were 39/11 in DPYD1; 33/17 in DPYD2 and 26/24 in CDA respectively. After 77 months of median follow-up, 18 pts died of tumor relapse, (7 in peritoneum and 11 in distant organs). Difference in survival was observed in DPYD1 pts only, for non wild-type over wild-type (p = 0.0283) and in any of the 3 genes tested heterozygous over homozygous pts (p = 0.0463). In 10 pts (20%) total dose was reduced by toxicity (5 diarrhea, 2 neutropenia, 2 hepatotoxicity, 1 vomiting), only 3 of them were homozygous. Conclusions: SNPs of DPYD1, DPYD2 and CDA predict outcome, survival and toxicity of GCP treated with 5-FU-based adjuvant chemotherapy.

No significant financial relationships to disclose.

Expression of adhesion molecules in endemic and epidemic Kaposi's sarcoma

Spindle cells and vascular endothelium in nodular lesions of AIDS associated (epidemic) and endemic Kaposi's sarcoma showed similar immunohistochemical patterns of expression for cell adhesion molecules and extracellular matrix proteins. Spindle cells as well as endothelium also expressed both alpha 5 and alpha V integrin subunits and ICAM-1 suggesting a possible role for inflammatory cytokines in spindle cell formation. The spindle cell compartment was rich in collagen, laminin, fibronectin and tenascin suggesting an important reactive component in the evolution of Kaposi's sarcoma. The lack of thrombospondin expression in the spindle cells favours the contention that they could be transitional, proliferating cells of endothelial origin. Specific expression of tat protein was not seen suggesting minimal if any HIV replication in these lesions. Our findings suggest similar histopathogenetic mechanisms for endemic and epidemic Kaposi's sarcoma. The clinically more malignant features of most AIDS related cases may reflect an important effect of systemic and focal cytokines in HIV patients and possibly other cofactor(s), i.e. tat protein in the induction and growth of the lesions.

Histochemical and functional evidence for a cholinergic innervation of the equine ureter

The distribution of acetylcholinesterase (AChE)-positive nerve fibers and cells, as well as the effects of acetylcholine (ACh) on ureteral smooth muscle and small resistance arteries were investigated in the equine ureter by means of histochemical, classic organ baths and myograph techniques. AChE-positive nerve fibers were widely distributed throughout the ureteral wall forming muscular, subepithelial and perivascular nerve plexuses, whose density was highest at the intravesical ureter. AChE-positive nerve cells were also identified grouped as adventitial or intramural ganglia. ACh increased concentration-dependently both the frequency of phasic contractile activity and basal tone of the isolated intravesical ureter, the pD2 values being 6.31 +/- 0.18 and 6.59 +/- 0.13, respectively. The ACh-induced motor effects in ureteral smooth muscle were blocked by atropine, giving pIC50 values of 8.58 +/- 0.08 and 9.68 +/- 0.05 for phasic activity and tone, respectively. Hexamethonium only inhibited ACh-evoked contractile activity at the highest concentration used. ACh elicited a potent endothelium-dependent relaxation of equine ureteral resistance arteries precontracted with 40 mM K-PSS, the pD2 value being 7.94 +/- 0.07. This relaxant response was abolished in the presence of the nitric oxide (NO) inhibitor, NG-nitro-L-arginine (L-NNA), the blockade being reversed by subsequent incubation with the NO exogenous substrate, L-arginine. The ACh-induced relaxation was competitively antagonized by atropine (pA2 = 10.05 +/- 0.18). The present results suggest the existence of a rich cholinergic innervation in the equine ureter which controls both ureteral smooth muscle and resistance arteries motor activity through the muscarinic effects of ACh. In addition, the ACh relaxant response in the ureteral resistance arteries seems to be mediated by NO.

High HIV seroprevalence and increased HIV-associated mortality among hospitalized patients with deep bacterial infections in Dar es Salaam, Tanzania

OBJECTIVES

To correlate deep bacterial infections with HIV infection and evaluate the influence of HIV on clinical picture and outcome in patients with meningitis, pneumonia or pyomyositis.

DESIGN

Case-control comparison of HIV seroprevalence between patients and an age- and sex-matched control group in a prospective cross-sectional study of hospitalized patients.

PARTICIPANTS

One hundred and sixty-five patients admitted to hospital with either purulent meningitis, pneumonia or pyomyositis and 165 age- and sex-matched controls from orthopaedic/trauma wards.

SETTING

University Hospital, Dar es Salaam, Tanzania.

OUTCOME MEASURES

Differences in HIV seroprevalence and mortality.

RESULTS

Of 78 patients with purulent meningitis, 19 (24%) were HIV-seropositive, compared with 13 (17%) in the control group (P = 0.345). Of 36 patients with meningitis seen before a meningococcal epidemic affected Dar es Salaam, there was a statistically significant association with HIV infection (P = 0.013). Ten out of 19 (53%) HIV-seropositives died, compared with nine out of 59 (15%) seronegatives (P = 0.028). Of patients with pneumococcal meningitis, five out of six (83%) seropositives died, compared with two out of 12 (17%) seronegatives (P = 0.013). Fifteen out of 45 (33%) patients with pneumonia were HIV-seropositive, compared with four (9%) in the control group (P = 0.001). There was no difference in mortality between seropositive and seronegative patients with pneumonia. HIV seroprevalence was 62% among 42 patients with pyomyositis and 12% among 42 controls (P less than 0.0001). Eighteen out of 25 (72%) seropositive patients with pyomyositis fulfilled the World Health Organization (WHO) clinical case definition for AIDS. Response to recommended antibiotic treatment was satisfactory among patients with pneumonia and pyomyositis.

CONCLUSIONS

These results show a strong association between pyomyositis, pneumonia and HIV infection. They also indicate an increased mortality associated with HIV infection in patients with pyogenic meningitis, especially pneumococcal meningitis. Pyomyositis should be considered an indicator of stage III HIV disease in the proposed WHO clinical staging system.

Spindle cell ploidy and proliferation in endemic and epidemic African Kaposi's sarcoma

Comparative studies of ploidy and proliferative activity of spindle cells in sections of 20 (skin, 17; lymph node, 3) biopsy specimens from African patients, 10 with endemic Kaposi's sarcoma (EKS) and 10 with AIDS-associated Kaposi's sarcoma (AKS) were performed by histopathology, feulgen-based DNA measurement and proliferating cell nuclear antigen (PCNA)/cyclin immunohistochemistry, respectively. All specimens were classified as nodular lesions with basically the same histology. In 17 cases immunostained for cyclin/PCNA, the percentage of proliferating spindle cells range between 2-18, with a higher mean rate in AKS although this was not statistically significant. In situ measurement of DNA showed no significant values greater than the diploid level of control cells indicating that spindle cells in both EKS and AKS have euploid DNA content. Our findings indicate that both EKS and AKS represent the same type of euploid low rate cell proliferations. This corroborates previous suggestions that KS could represent a reactive process to yet undefined stimulus rather than a clonal proliferation, of transformed malignant cells.