RNASEH2B loss and PARP inhibition in advanced prostate cancer.

BACKGROUND: Clinical trials have suggested antitumor activity from PARP inhibition beyond homologous recombination deficiency (HRD). RNASEH2B loss is unrelated to HRD and preclinically sensitizes to PARP inhibition. The current study reports on RNASEH2B protein loss in advanced prostate cancer and its association with RB1 protein loss, clinical outcome and clonal dynamics during treatment with PARP inhibition in a prospective clinical trial. METHODS: Whole tumor biopsies from multiple cohorts of patients with advanced prostate cancer were interrogated using whole-exome sequencing (WES), RNA sequencing (bulk and single nucleus) and immunohistochemistry (IHC) for RNASEH2B and RB1. Biopsies from patients treated with olaparib in the TOPARP-A and TOPARP-B clinical trials were used to evaluate RNASEH2B clonal selection during olaparib treatment. RESULTS: Shallow co-deletion of RNASEH2B and adjacent RB1, co-located at chromosome 13q14, was common, deep co-deletion infrequent, and gene loss associated with lower mRNA expression. In castration-resistant PC (CRPC) biopsies, RNASEH2B and RB1 mRNA expression correlated, but single nucleus RNA sequencing indicated discordant loss of expression. IHC studies showed that loss of the two proteins often occurred independently, arguably due to stochastic second allele loss. Pre- and post-treatment metastatic CRPC (mCRPC) biopsy studies from BRCA1/2 wildtype tumors, treated on the TOPARP phase II trial, indicated that olaparib eradicates RNASEH2B-loss tumor subclones. CONCLUSION: PARP inhibition may benefit men suffering from mCRPC by eradicating tumor subclones with RNASEH2B loss. CLINICALTRIALS: gov NCT01682772FUNDING. AstraZeneca; Cancer Research UK; Medical Research Council; Cancer Research UK; Prostate Cancer UK; Movember Foundation; Prostate Cancer Foundation.

Development and Validation of a New BAG-1L-Specific Antibody to Quantify BAG-1L Protein Expression in Advanced Prostate Cancer.

BCL-2-associated athanogene-1L (BAG-1L) is a critical co-regulator that binds to and enhances the transactivation function of the androgen receptor, leading to prostate cancer development and progression. Studies investigating the clinical importance of BAG-1L protein expression in advanced prostate cancer have been limited by the paucity of antibodies that specifically recognize the long isoform. In this study, we developed and validated a new BAG-1L-specific antibody using multiple orthogonal methods across several cell lines with and without genomic manipulation of BAG-1L and all BAG-1 isoforms. Following this, we performed exploratory immunohistochemistry to determine BAG-1L protein expression in normal human, matched castration-sensitive prostate cancer (CSPC) and castration-resistant prostate cancer (CRPC), unmatched primary and metastatic CRPC, and early breast cancer tissues. We demonstrated higher BAG-1L protein expression in CRPC metastases than in unmatched, untreated, castration-sensitive prostatectomies from men who remained recurrence-free for 5 years. In contrast, BAG-1L protein expression did not change between matched, same patient, CSPC and CRPC biopsies, suggesting that BAG-1L protein expression may be associated with more aggressive biology and the development of castration resistance. Finally, in a cohort of patients who universally developed CRPC, there was no association between BAG-1L protein expression at diagnosis and time to CRPC or overall survival, and no association between BAG-1L protein expression at CRPC biopsy and clinical outcome from androgen receptor targeting therapies or docetaxel chemotherapy. The limitations of this study include the requirement to validate the reproducibility of the assay developed, the potential influence of pre-analytical factors, timing of CRPC biopsies, relatively small patient numbers, and heterogenous therapies on BAG-1L protein expression, and the clinical outcome analyses performed. We describe a new BAG-1L-specific antibody that the research community can further develop to elucidate the biological and clinical significance of BAG-1L protein expression in malignant and nonmalignant diseases.

Germline ATM Mutations Detected by Somatic DNA Sequencing in Lethal Prostate Cancer.

Background: Germline mutations in the ataxia telangiectasia mutated (ATM) gene occur in 0.5-1% of the overall population and are associated with tumour predisposition. The clinical and pathological features of ATM-mutated prostate cancer (PC) are poorly defined but have been associated with lethal PC. Objective: To report on the clinical characteristics including family history and clinical outcomes of a cohort of patients with advanced metastatic castration-resistant PC (CRPC) who were found to have germline ATM mutations after mutation detection by initial tumour DNA sequencing. Design setting and participants: We acquired germline ATM mutation data by saliva next-generation sequencing from patients with ATM mutations in PC biopsies sequenced between January 2014 and January 2022. Demographics, family history, and clinical data were collected retrospectively. Outcome measurements and statistical analysis: Outcome endpoints were based on overall survival (OS) and time from diagnosis to CRPC. Data were analysed using R version 3.6.2 (R Foundation for Statistical Computing, Vienna, Austria). Results and limitations: Overall, seven patients (n = 7/1217; 0.6%) had germline ATM mutations detected, with five of them having a family history of malignancies, including breast, prostate, pancreas, and gastric cancer; leukaemia; and lymphoma. Two patients had concomitant somatic mutations in tumour biopsies in genes other than ATM, while two patients were found to carry more than one ATM pathogenic mutation. Five tumours in germline ATM variant carriers had loss of ATM by immunohistochemistry. The median OS from diagnosis was 7.1 yr (range 2.9-14 yr) and the median OS from CRPC was 5.3 yr (range 2.2-7.3 yr). When comparing these data with PC patients sequenced by The Cancer Genome Atlas, we found that the spatial localisation of mutations was similar, with distribution of alterations occurring on similar positions in the ATM gene. Interestingly, these include a mutation within the FRAP-ATM-TRRAP (FAT) domain, suggesting that this represents a mutational hotspot for ATM. Conclusions: Germline ATM mutations are rare in patients with lethal PC but occur at mutational hotspots; further research is warranted to better characterise the family histories of these men and PC clinical course. Patient summary: In this report, we studied the clinical and pathological features of advanced prostate cancers associated with germline mutations in the ATM gene. We found that most patients had a strong family history of cancer and that this mutation might predict the course of these prostate cancers, as well as response to specific treatments.

'You give me fever!': are health services ready for immune cell engager therapy in advanced solid malignancies?

Immune cell engager therapeutic strategies using bioengineered molecules to redirect immune cells into tumor are starting to demonstrate promising clinical activity in multiple early phase trials across numerous targets and a range of solid tumor types. These therapies, however, carry the risk of exaggerated cytokine-mediated on-target off-tumor adverse events that require highly specialized inpatient facilities. We report here the Royal Marsden experience of treating patients with advanced solid tumors on early phase immune engager clinical trials in a dedicated inpatient facility, focusing specifically on patterns of cytokine-mediated toxicity seen and proposing a risk-mitigation algorithm for the safe, feasible and scalable delivery of these therapies.

Expression of PD-L1 in cervical carcinoma and its impact on survival associated with T-cell infiltration and FoxP3 expression.

Background: The PD-1/PD-L1 signaling axis is currently the most elucidated mechanism for tumor evasion of T-cell-mediated immunity. Nevertheless, few data are available regarding its impact on cervical cancer and the relationship with lymphocytic infiltrates. Methods: A retrospective assessment of all cases of cervical neoplasia treated in Caxias do Sul General Hospital, Brazil, between 2012 and 2016 was performed. Clinical and pathological data were collected from electronic records and analyzed. Original slides were independently reviewed by three pathologists to confirm diagnoses and to assess the immunohistochemical expression of PD-L1 and FoxP3 in tumor cells and lymphocytic infiltrates. Results: PD-L1 staining was present in 32.2% of the 59 cervical samples. Median overall survival time of the PD-L1-negative group was 47.8 months, a time point not yet reached by the PD-L1-positive group (p=0.968). Median progression-free survival was 24.3 months for PD-L1-negative and 11.5 months for PD-L1-positive patients (p=0.263). PD-L1 staining was found in 27.1% of the lymphocytic infiltrates, and survival analysis revealed no difference between PD-L1-positive and PD-L1-negative samples. There was no impact on survival related to FoxP3 staining in neither tumor samples nor lymphocytic infiltrates. Conclusion: Although the median progression-free survival times differed, the difference was not statistically significant. Our study corroborates the rationale that PD-L1 expression in cervical neoplasms has no impact on survival. PD-L1 expression in peritumoral lymphocytes revealed no impact on infiltration volume nor survival. Keywords: uterine cervical neoplasms, tumor-infiltrating lymphocytes, cancer, tumor microenvironment, survival.

Analysis of time interval between breast cancer diagnosis and treatment / Análise do tempo decorrido entre diagnóstico e tratamento do câncer de mama

Introduction: Breast cancer has a good prognosis when treated early. However, the mortality rate in Brazil is still high. The time interval between radiological suspicion and diagnosis/treatment impacts the survival. Methods: This is a retrospective crosssectional study that assessed patients treated at a reference center, with abnormal breast imaging findings and subsequent confirmation of breast cancer, from January 2011 to June 2015. We reviewed variables related to the dates of the abnormal test result, first mastology appointment, biopsy, surgery, and the start of chemotherapy ­ when indicated. Time intervals were compared using the Friedman and Kruskal-Wallis tests with the software SPSS® 23.0. Results: We analyzed 65 patients. The median time between the abnormal test result and first mastology appointment was 35 days; between first mastology appointment and biopsy, 31 days; between biopsy and surgery, 85 days; and between surgery and chemotherapy, 137 days. The last two intervals showed significant differences (p<0.001). Discussion: Breast cancer patients had a significant delay until surgery and the start of chemotherapy. Early integration of the multidisciplinary team involved in this process and internal audits are necessary to optimize time intervals.

Introdução: O câncer de mama apresenta bom prognóstico quando tratado precocemente, entretanto, a mortalidade no Brasil continua elevada. O tempo entre suspeita radiológica e diagnóstico e tratamento tem impacto na sobrevida. Métodos: Foi realizado um estudo transversal e retrospectivo que avaliou pacientes atendidas em centro de referência com imagem mamária alterada e posterior confirmação de câncer de mama de janeiro de 2011 a junho e 2015. Foram revisadas variáveis relacionadas às datas do exame alterado, da primeira consulta, da biópsia, da cirurgia e do início da quimioterapia, quando indicada. Os intervalos de tempo foram comparados pelos testes Friedman e Kruskal-Wallis, pelo programa SPSS® 23.0. Resultados: Foram analisadas 65 pacientes. A mediana de tempo entre exame alterado e primeira consulta foi 35 dias, entre consulta na mastologia e biópsia foi 31 dias, entre biópsia e cirurgia foi 85 dias e entre cirurgia e quimioterapia foi 137 dias. Foram observadas diferenças significativas nos dois últimos intervalos (p<0,001). Discussão: As pacientes com câncer de mama apresentaram atraso significativo até a cirurgia e até o início da quimioterapia. Há necessidade da integração precoce da equipe multidisciplinar implicada nesse processo e auditorias internas a fim de otimizar os intervalos de tempo

ANDROGEN RECEPTOR EXPRESSION IN TRIPLE NEGATIVE BREAST CANCER AND ITS RELATIONSHIP TO PROGNOSTIC FACTORS / Expressão de receptor de androgênio em câncer de mama triplo negativo e sua relação com fatores prognósticos

Objective: Triple negative breast cancer (TNBC) is a subset of tumors with an aggressive intrinsic biology, resulting in poor prognosis. Androgen receptor (AR) is currently one of the most studied biomarkers in TNBC, playing a role in the genesis and development of breast cancer. Methods: In this cross-sectional study, we retrospectively reviewed the medical records of all patients with TNBC who received care from 2012 to 2014 at a single health center in southern Brazil. Histological material from breast tumors was analyzed by immunohistochemistry for AR expression and related to age, histological grade, tumor-infiltrating lymphocytes (TILs), and Ki-67. Results: Of 34 TNBC cases identified, 23 (67.6%) were AR negative and 11 (32.4%) were AR positive. The average age of the patients was 51.9 years (range: 30­82 years). Among positive cases, AR was weakly expressed in 6 and strongly expressed in 5 cases. Most patients (n=28; 82.0%) had poorly differentiated tumors. Mean Ki-67 expression was 65.0% in AR-negative and 43.6% in AR-positive cases (p<0.05). There was a significant association between age and AR expression (p<0.005), which was associated with mean age 70.8 years in the strongly AR-positive group and 42.3 years in the weakly AR-positive group. The mean percentage of TILs was 38.6% in AR-positive and 39.1% in AR-negative cases (p=0.391). Conclusion: There was no significant association between AR expression and histological grade or TILs. AR positivity in TNBC was associated with older age and tumors with lower Ki-67 expression, indicating two subgroups with distinct phenotypes in patients with TNBC.

Objetivo: O câncer de mama negativo triplo (triple negative breast cancer ­ TNBC) é um subtipo de tumores com biologia intrínseca agressiva, resultando em pior prognóstico. O receptor de andrógeno (androgen receptor ­ AR) é atualmente um dos biomarcadores mais estudados em TNBC, desempenhando papel na gênese e no desenvolvimento do câncer de mama. Métodos: Neste estudo transversal, revisamos retrospectivamente os registros médicos de todos os pacientes com TNBC que receberam atendimento de 2012 a 2014 em um único centro no sul do Brasil. O material histológico dos tumores de mama foi analisado por imuno-histoquímica para a expressão de AR e relacionado a idade, grau histológico, linfócitos infiltrantes de tumores (TILs) e Ki-67. Resultados: Dos 34 casos identificados de TNBC, 23 (67,6%) eram AR negativos e 11 (32,4%), AR positivos. A idade média foi de 51,9 anos (30­82 anos). Entre os casos positivos, AR foi fracamente expresso em 6 e fortemente expresso em 5 casos. A maioria dos pacientes (n=28, 82,0%) apresentou tumores pouco diferenciados. A expressão média de Ki-67 foi de 65,0% em AR-negativo e 43,6% em AR-positivo (p<0,05). Houve associação significativa entre a idade e a expressão de AR (p<0,005), associada à idade média de 70,8 anos no grupo com AR fortemente positivo e de 42,3 anos no grupo com AR fracamente positivo. A porcentagem média de TILs foi de 38,6% em AR-positivo e de 39,1% em AR-negativo (p=0,391). Não houve associação significativa entre expressão AR e grau histológico ou TILs. Conclusão: A positividade de AR em TNBC foi associada com idade mais avançada e tumores com menor expressão de Ki-67, indicando dois subgrupos com fenótipos distintos em pacientes com TNBC.