Analysis of the prevalence of microsatellite instability in prostate cancer and response to immune checkpoint blockade Journal Article

Authors: Abida, W.; Cheng, M. L.; Armenia, J.; Middha, S.; Autio, K. A.; Vargas, H. A.; Rathkopf, D.; Morris, M. J.; Danila, D. C.; Slovin, S. F.; Carbone, E.; Barnett, E. S.; Hullings, M.; Hechtman, J. F.; Zehir, A.; Shia, J.; Jonsson, P.; Stadler, Z. K.; Srinivasan, P.; Laudone, V. P.; Reuter, V.; Wolchok, J. D.; Socci, N. D.; Taylor, B. S.; Berger, M. F.; Kantoff, P. W.; Sawyers, C. L.; Schultz, N.; Solit, D. B.; Gopalan, A.; Scher, H. I.
Article Title: Analysis of the prevalence of microsatellite instability in prostate cancer and response to immune checkpoint blockade
Abstract: Importance: The anti-programmed cell death protein 1 (PD-1) antibody pembrolizumab is approved by the US Food and Drug Administration for the treatment of microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) solid tumors, but the prevalence of MSI-H/dMMR prostate cancer and the clinical utility of immune checkpoint blockade in this disease subset are unknown. Objective: To define the prevalence of MSI-H/dMMR prostate cancer and the clinical benefit of anti-PD-1/programmed cell death 1 ligand 1 (PD-L1) therapy in this molecularly defined population. Design, Setting, and Participants: In this case series, 1551 tumors from 1346 patients with prostate cancer undergoing treatment at Memorial Sloan Kettering Cancer Center were prospectively analyzed using a targeted sequencing assay from January 1, 2015, through January 31, 2018. Patients had a diagnosis of prostate cancer and consented to tumor molecular profiling when a tumor biopsy was planned or archival tissue was available. For each patient, clinical outcomes were reported, with follow-up until May 31, 2018. Main Outcomes and Measures: Tumor mutation burden and MSIsensor score, a quantitative measure of MSI, were calculated. Mutational signature analysis and immunohistochemistry for MMR protein expression were performed in select cases. Results: Among the 1033 patients who had adequate tumor quality for MSIsensor analysis (mean [SD] age, 65.6 [9.3] years), 32 (3.1%) had MSI-H/dMMR prostate cancer. Twenty-three of 1033 patients (2.2%) had tumors with high MSIsensor scores, and an additional 9 had indeterminate scores with evidence of dMMR. Seven of the 32 MSI-H/dMMR patients (21.9%) had a pathogenic germline mutation in a Lynch syndrome-associated gene. Six patients had more than 1 tumor analyzed, 2 of whom displayed an acquired MSI-H phenotype later in their disease course. Eleven patients with MSI-H/dMMR castration-resistant prostate cancer received anti-PD-1/PD-L1 therapy. Six of these (54.5%) had a greater than 50% decline in prostate-specific antigen levels, 4 of whom had radiographic responses. As of May 2018, 5 of the 6 responders (5 of 11 total [45.5%]) were still on therapy for as long as 89 weeks. Conclusions and Relevance: The MSI-H/dMMR molecular phenotype is uncommon yet therapeutically meaningful in prostate cancer and can be somatically acquired during disease evolution. Given the potential for durable responses to anti-PD-1/PD-L1 therapy, these findings support the use of prospective tumor sequencing to screen all patients with advanced prostate cancer for MSI-H/dMMR. Because not all patients with the MSI-H/dMMR phenotype respond, further studies should explore mechanisms of resistance. © 2019 American Medical Association. All rights reserved.
Journal Title: JAMA Oncology
Volume: 5
Issue: 4
ISSN: 2374-2437
Publisher: American Medical Association  
Date Published: 2019-04-01
Start Page: 471
End Page: 478
Language: English
DOI: 10.1001/jamaoncol.2018.5801
PROVIDER: scopus
PUBMED: 30589920
Notes: Article -- Export Date: 1 May 2019 -- Source: Scopus
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MSK Authors
  1. Charles L Sawyers
    157 Sawyers
  2. Vincent Laudone
    60 Laudone
  3. Susan Slovin
    186 Slovin
  4. Michael Morris
    283 Morris
  5. Jedd D Wolchok
    672 Wolchok
  6. David Solit
    440 Solit
  7. Karen Anne Autio
    52 Autio
  8. Zsofia Kinga Stadler
    153 Stadler
  9. Anuradha Gopalan
    277 Gopalan
  10. Jinru Shia
    466 Shia
  11. Dana Elizabeth Rathkopf
    144 Rathkopf
  12. Ahmet Zehir
    159 Zehir
  13. Nicholas D Socci
    188 Socci
  14. Michael Forman Berger
    393 Berger
  15. Victor Reuter
    926 Reuter
  16. Howard Scher
    837 Scher
  17. Daniel C Danila
    84 Danila
  18. Wassim Abida
    42 Abida
  19. Barry Stephen Taylor
    144 Taylor
  20. Nikolaus D Schultz
    206 Schultz
  21. Jaclyn Frances Hechtman
    109 Hechtman
  22. Sumit   Middha
    57 Middha
  23. Karl Philip Jonsson
    25 Jonsson
  24. Philip Wayne Kantoff
    69 Kantoff
  25. Joshua   Armenia
    24 Armenia
  26. Michael Lain Cheng
    5 Cheng