Identification of RAD17 as a candidate cancer predisposition gene in families with histories of pancreatic and breast cancers.

BACKGROUND: Among the 10% of pancreatic cancers that occur in a familial context, around a third carry a pathogenic variant in a cancer predisposition gene. Genetic studies of pancreatic cancer predisposition are limited by high mortality rates amongst index patients and other affected family members. The genetic risk for pancreatic cancer is often shared with breast cancer susceptibility genes, most notably BRCA2, PALB2, ATM and BRCA1. Therefore, we hypothesized that additional shared genetic etiologies might be uncovered by studying families presenting with both breast and pancreatic cancer. METHODS: Focusing on a multigene panel of 276 DNA Damage Repair (DDR) genes, we performed next-generation sequencing in a cohort of 41 families with at least three breast cancer cases and one pancreatic cancer. When the index patient with pancreatic cancer was deceased, close relatives (first or second-degree) affected with breast cancer were tested (39 families). RESULTS: We identified 27 variants of uncertain significance in DDR genes. A splice site variant (c.1605 + 2T > A) in the RAD17 gene stood out, as a likely loss of function variant. RAD17 is a checkpoint protein that recruits the MRN (MRE11-RAD50-NBS1) complex to initiate DNA signaling, leading to DNA double-strand break repair. CONCLUSION: Within families with breast and pancreatic cancer, we identified RAD17 as a novel candidate predisposition gene. Further genetic studies are warranted to better understand the potential pathogenic effect of RAD17 variants and in other DDR genes.

Identification of candidate cancer predisposing variants by performing whole-exome sequencing on index patients from BRCA1 and BRCA2-negative breast cancer families.

BACKGROUND: In the majority of familial breast cancer (BC) families, the etiology of the disease remains unresolved. To identify missing BC heritability resulting from relatively rare variants (minor allele frequency ≤ 1%), we have performed whole exome sequencing followed by variant analysis in a virtual panel of 492 cancer-associated genes on BC patients from BRCA1 and BRCA2 negative families with elevated BC risk. METHODS: BC patients from 54 BRCA1 and BRCA2-negative families with elevated BC risk and 120 matched controls were considered for germline DNA whole exome sequencing. Rare variants identified in the exome and in a virtual panel of cancer-associated genes [492 genes associated with different types of (hereditary) cancer] were compared between BC patients and controls. Nonsense, frame-shift indels and splice-site variants (strong protein-damaging variants, called PDAVs later on) observed in BC patients within the genes of the panel, which we estimated to possess the highest probability to predispose to BC, were further validated using an alternative sequencing procedure. RESULTS: Exome- and cancer-associated gene panel-wide variant analysis show that there is no significant difference in the average number of rare variants found in BC patients compared to controls. However, the genes in the cancer-associated gene panel with nonsense variants were more than two-fold over-represented in women with BC and commonly involved in the DNA double-strand break repair process. Approximately 44% (24 of 54) of BC patients harbored 31 PDAVs, of which 11 were novel. These variants were found in genes associated with known or suspected BC predisposition (PALB2, BARD1, CHEK2, RAD51C and FANCA) or in predisposing genes linked to other cancer types but not well-studied in the context of familial BC (EXO1, RECQL4, CCNH, MUS81, TDP1, DCLRE1A, DCLRE1C, PDE11A and RINT1) and genes associated with different hereditary syndromes but not yet clearly associated with familial cancer syndromes (ABCC11, BBS10, CD96, CYP1A1, DHCR7, DNAH11, ESCO2, FLT4, HPS6, MYH8, NME8 and TTC8). Exome-wide, only a few genes appeared to be enriched for PDAVs in the familial BC patients compared to controls. CONCLUSIONS: We have identified a series of novel candidate BC predisposition variants/genes. These variants/genes should be further investigated in larger cohorts/case-control studies. Other studies including co-segregation analyses in affected families, locus-specific loss of heterozygosity and functional studies should shed further light on their relevance for BC risk.

Retrospective comparison of two consecutive cohorts of adjuvant chemotherapy regimens of cyclophosphamide with either docetaxel or paclitaxel in older patients with early breast cancer.

Adjuvant chemotherapy with docetaxel/cyclophosphamide (TC) is adopted worldwide as a valuable option for elderly patients with high-risk early breast cancer. Some studies suggest that paclitaxel may have a better therapeutic ratio than docetaxel. Therefore we have implemented an adjuvant chemotherapy in which docetaxel was replaced by paclitaxel. We report here the retrospective analysis of that cohort and make a safety comparison with an earlier TC cohort in the same target population. This retrospective analysis demonstrates the feasibility of paclitaxel/cyclophosphamide as an alternative, better tolerated adjuvant regimen for elderly patients. Further evaluation and assessment of noninferiority to TC is warranted.

Phase II Trial Assessing the Repeatability and Tumor Uptake of [68Ga]Ga-HER2 Single-Domain Antibody PET/CT in Patients with Breast Carcinoma.

Human epidermal growth factor receptor 2 (HER2) status is used for decision-making in breast carcinoma treatment. The status is obtained through immunohistochemistry or in situ hybridization. These two methods have the disadvantage of necessitating tissue sampling, which is prone to error due to tumor heterogeneity or interobserver variability. Whole-body imaging might be a solution to map HER2 expression throughout the body. Methods: Twenty patients with locally advanced or metastatic breast carcinoma (5 HER2-positive and 15 HER2-negative patients) were included in this phase II trial to assess the repeatability of uptake quantification and the extended safety of the [68Ga]Ga-NOTA-anti-HER2 single-domain antibody (sdAb). The tracer was injected, followed by a PET/CT scan at 90 min. Within 8 d, the procedure was repeated. Blood samples were taken for antidrug antibody (ADA) assessment and liquid biopsies. On available tissues, immunohistochemistry, in situ hybridization, and mass spectrometry were performed to determine the correlation of HER2 status with uptake values measured on PET. If relevant preexisting [18F]FDG PET/CT images were available (performed as standard of care), a comparison was made. Results: With a repeatability coefficient of 21.8%, this imaging technique was repeatable. No clear correlation between PET/CT uptake values and pathology could be established, as even patients with low levels of HER2 expression showed moderate to high uptake. Comparison with [18F]FDG PET/CT in 16 patients demonstrated that in 7 patients, [68Ga]Ga-NOTA-anti-HER2 shows interlesional heterogeneity within the same patient, and [18F]FDG uptake did not show the same heterogeneous uptake in all patients. In some patients, the extent of disease was clearer with the [68Ga]Ga-NOTA-anti-HER2-sdAb. Sixteen adverse events were reported but all without a clear relationship to the tracer. Three patients with preexisting ADAs did not show adverse reactions. No new ADAs developed. Conclusion: [68Ga]Ga-NOTA-anti-HER2-sdAb PET/CT imaging shows similar repeatability to [18F]FDG. It is safe for clinical use. There is tracer uptake in cancer lesions, even in patients previously determined to be HER2-low or -negative. The tracer shows potential in the assessment of interlesional heterogeneity of HER2 expression. In a subset of patients, [68Ga]Ga-NOTA-anti-HER2-sdAb uptake was seen in lesions with no or low [18F]FDG uptake. These findings support further clinical development of [68Ga]Ga-NOTA-anti-HER2-sdAb as a PET/CT tracer in breast cancer patients.

Efficacy of a Flat Low Dose of Nivolumab in Advanced Cancer: A Retrospective Case Series.

BACKGROUND/AIM: Immunotherapy with PD-1/PDL1 blocking monoclonal antibodies has improved survival compared to the standard-of-care chemotherapy for several malignancies at different stages of these malignancies. Due to several reasons, many cancer patients in medical need have no access to these drugs. In this study, we aimed to investigate whether a low dose of nivolumab could also lead to a therapeutic response. PATIENTS AND METHODS: Patients with advanced cancer were treated with a flat low dose of 10 mg of nivolumab IV every two weeks at no drug cost. RESULTS: Disease control was noted in nine of the 18 patients. Two patients achieved complete remission, two had prolonged partial remission, and five had stable disease, of these only two experienced adverse events. CONCLUSION: A flat low dose of nivolumab may have clinical activity and is a cheap therapeutic option in patients in medical need for whom standard-dose immune checkpoint inhibitors are not accessible for any reason.

Real life safety and effectiveness of nivolumab in older patients with non-small cell lung cancer: Results from the Belgian compassionate use program.

OBJECTIVES: To compare real life effectiveness and safety of nivolumab in patients with non-small cell lung cancer (NSCLC), according to age and Eastern Cooperative Group performance status (ECOG-PS). METHODS: We performed a retrospective analysis of patients treated with nivolumab for NSCLC within a Belgian compassionate use program from July 2015 until December 2016. Safety and effectiveness were compared between patients aged ≥70 years and < 70 years and between ECOG-PS 0/1 and ≥ 2. RESULTS: A total of 324 patients with NSCLC were included. There was no significant difference between older (≥70) and younger (<70 years) patients with regards to progression free survival (PFS) (4 months (95%CI 2.6;4.8) versus 3.7 months (95%CI 1;7), p = 0.483) and overall survival (OS) (9.3 months (95% CI 5.5;13.1 months) versus 8.4 months (95%CI 6.3; 10.5), p = 0,638). Patients with an ECOG-PS ≥2 had a significant lower median PFS and OS compared to patients with an ECOG-PS 0-1 (2.2 (95%CI 1.4; 2.9) versus 5.6 months (95%CI 4.1; 7.1), p = 0.001 and 3.4 (95%CI 2.3; 4.5) versus 11.1 months (95%CI 8.9; 13.2), p < 0.001 respectively). No significant difference in all grades or grade 3/4 adverse events (AEs) were observed between the different age groups (p = 0.526 and p = 0.603 respectively). Patients with an ECOG-PS 0/1 had significantly more all grades AEs (p = 0.009) but no difference in grade 3/4 AEs was observed (p = 0.406) compared to ECOG-PS ≥2. CONCLUSION: This real life retrospective study confirms that safety and effectiveness of nivolumab is similar between different age groups, but that effectiveness is driven by performance status.