Diagnostic Utility of Menin Immunohistochemistry in Patients With Multiple Endocrine Neoplasia Type 1 Syndrome

A clinical diagnosis of multiple endocrine neoplasia type 1 (MEN1) syndrome is usually confirmed with genetic testing in the germline. It is expected that menin protein expression is lost in MEN1-related tumors. Therefore, we investigated the potential of menin immunohistochemistry in parathyroid adenomas as an additional tool in the recognition and genetic diagnosis of MEN1 syndrome. Local pathology archives were searched for parathyroid tumors from patients with MEN1 syndrome and without MEN1, including sporadic, patients with multiple endocrine neoplasia type 2A and hyperparathyroidism-jaw parathyroid tumors. Menin immunohistochemistry was performed and its use to identify MEN1-related tumors was assessed. Twenty-nine parathyroid tumors from 16 patients with MEN1 and 61 patients with parathyroid tumors from 32 non-MEN1 were evaluated. Immunohistochemical nuclear menin loss in one or more tumors was found in 100% of patients with MEN1 and 9% of patients with non-MEN1. In patients with multiple tumors, menin loss in at least one tumor was seen in 100% of 8 patients with MEN1 and 21% of patients with 14 non-MEN1. Using a cutoff of at least 2 tumors showing menin loss per patient, the positive and negative predictive values for the diagnosis MEN1 were both 100%. The practical and additional value of menin immunohistochemistry in clinical genetic MEN1 diagnosis is further illustrated by menin immunohistochemistry in 2 cases with a germline variant of unknown significance in the MEN1 gene. Menin immunohistochemistry is useful in the recognition of MEN1 syndrome as well as in the clinical genetic analysis of patients with inconclusive MEN1 germline testing.

Genetic Aspects and Molecular Testing in Prostate Cancer: A Report from a Dutch Multidisciplinary Consensus Meeting

Background

Germline and tumour genetic testing in prostate cancer (PCa) is becoming more broadly accepted, but testing indications and clinical consequences for carriers in each disease stage are not yet well defined.

Objective

To determine the consensus of a Dutch multidisciplinary expert panel on the indication and application of germline and tumour genetic testing in PCa.

Design setting and participants

The panel consisted of 39 specialists involved in PCa management. We used a modified Delphi method consisting of two voting rounds and a virtual consensus meeting.

Outcome measurements and statistical analysis

Consensus was reached if ≥75% of the panellists chose the same option. Appropriateness was assessed by the RAND/UCLA appropriateness method.

Results and limitations

Of the multiple-choice questions, 44% reached consensus. For men without PCa having a relevant family history (familial PCa/BRCA-related hereditary cancer), follow-up by prostate-specific antigen was considered appropriate. For patients with low-risk localised PCa and a family history of PCa, active surveillance was considered appropriate, except in case of the patient being a BRCA2 germline pathogenic variant carrier. Germline and tumour genetic testing should not be done for nonmetastatic hormone-sensitive PCa in the absence of a relevant family history of cancer. Tumour genetic testing was deemed most appropriate for the identification of actionable variants, with uncertainty for germline testing. For tumour genetic testing in metastatic castration-resistant PCa, consensus was not reached for the timing and panel composition. The principal limitations are as follows: (1) a number of topics discussed lack scientific evidence, and therefore the recommendations are partly opinion based, and (2) there was a small number of experts per discipline.

Conclusions

The outcomes of this Dutch consensus meeting may provide further guidance on genetic counselling and molecular testing related to PCa.

Patient summary

A group of Dutch specialists discussed the use of germline and tumour genetic testing in prostate cancer (PCa) patients, indication of these tests (which patients and when), and impact of these tests on the management and treatment of PCa.

Multicenter Comparison of Molecular Tumor Boards in The Netherlands: Definition, Composition, Methods, and Targeted Therapy Recommendations

BACKGROUND

Molecular tumor boards (MTBs) provide rational, genomics-driven, patient-tailored treatment recommendations. Worldwide, MTBs differ in terms of scope, composition, methods, and recommendations. This study aimed to assess differences in methods and agreement in treatment recommendations among MTBs from tertiary cancer referral centers in The Netherlands.

MATERIALS AND METHODS

MTBs from all tertiary cancer referral centers in The Netherlands were invited to participate. A survey assessing scope, value, logistics, composition, decision-making method, reporting, and registration of the MTBs was completed through on-site interviews with members from each MTB. Targeted therapy recommendations were compared using 10 anonymized cases. Participating MTBs were asked to provide a treatment recommendation in accordance with their own methods. Agreement was based on which molecular alteration(s) was considered actionable with the next line of targeted therapy.

RESULTS

Interviews with 24 members of eight MTBs revealed that all participating MTBs focused on rare or complex mutational cancer profiles, operated independently of cancer type-specific multidisciplinary teams, and consisted of at least (thoracic and/or medical) oncologists, pathologists, and clinical scientists in molecular pathology. Differences were the types of cancer discussed and the methods used to achieve a recommendation. Nevertheless, agreement among MTB recommendations, based on identified actionable molecular alteration(s), was high for the 10 evaluated cases (86%).

CONCLUSION

MTBs associated with tertiary cancer referral centers in The Netherlands are similar in setup and reach a high agreement in recommendations for rare or complex mutational cancer profiles. We propose a "Dutch MTB model" for an optimal, collaborative, and nationally aligned MTB workflow.

IMPLICATIONS FOR PRACTICE

Interpretation of genomic analyses for optimal choice of target therapy for patients with cancer is becoming increasingly complex. A molecular tumor board (MTB) supports oncologists in rationalizing therapy options. However, there is no consensus on the most optimal setup for an MTB, which can affect the quality of recommendations. This study reveals that the eight MTBs associated with tertiary cancer referral centers in The Netherlands are similar in setup and reach a high agreement in recommendations for rare or complex mutational profiles. The Dutch MTB model is based on a collaborative and nationally aligned workflow with interinstitutional collaboration and data sharing.

Olaparib monotherapy in pretreated patients with BRCA1/2 alterations: Results of a DRUP trial cohort

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Background: Extensive molecular profiling in cancer regularly reveals targets for which approved drugs are available in tumor types outside the registered label. Efficacy of off-label use of these drugs is unavailable. Access to these drugs for pts is challenging. In the Drug Rediscovery Protocol (DRUP, Van der Velden et al, Nature 2019), pts are treated based on their tumor molecular profile. Here, we present the results of the successful cohort “Olaparib for tumors with BRCA1/2 alterations”. Methods: Twenty five adult cancer patients (pts) who exhausted all treatment options and had BRCA1/2 loss of function (LoF) mutations (found in routine diagnostics) were included. No pts were eligible for on-label treatment with PARP inhibitors. Pts were treated with olaparib until disease progression or unacceptable toxicity. The primary endpoint was clinical benefit (CB: objective response or stable disease (SD) ≥ 16 weeks). Pts were enrolled using a Simon-like two-stage model, with 8 pts in stage 1 and up to 24 pts in stage 2 if at least 1 pt had CB in stage 1. A fresh frozen biopsy was obtained from each pt for whole genome sequencing (WGS) and target confirmation. Results: Fourteen pts (56%) had CB. The objective response rate was 32%. Nine different cancer types were included: prostate (n=11), breast (n=4), ovarian (n=2), pancreatic (n=3), colorectal (n=2), biliary tract (n=2), kidney (n=1), adrenal gland (n=1) and endometrial (n=1). WGS could be performed on 58% of baseline tumor biopsies, confirming the original BRCA1/2 mutations in 86%. CB was observed in pts with both somatic and germline BRCA alterations and across tumor types. CB was only observed in cases with biallelic loss of BRCA1/2 in the tumor and when classified as HRD by a pan-cancer homologous recombination deficiency classifier (CHORD), which relies on genome-wide SNV, indel, and SV mutational footprints for HRD detection. No evidence of complete BRCA loss and HRD was observed in 5 pts with PD, while 4 patients with effective BRCA complete loss and HRD also had PD. WGS analysis of these pts suggested resistance mechanisms due to other oncogenic drivers (e.g FGFR1 amplification, CTNNB1 stabilization, KEAP1 inactivation). Conclusions: Olaparib seems to be an effective treatment option for pts with BRCA1/2 LoF mutated malignancies, regardless of histology, for both germline and somatic alterations, which needs confirmation in an independent cohort. CB of olaparib was observed in malignancies showing biallelic loss of BRCA1/2 and when classified as HRD, indicating the importance of the BRCA/HRD signature status. Clinical trial information: NCT02925234 .