Integrated genomic characterization of oral carcinomas in post-hematopoietic stem cell transplantation survivors

Oral Oncol. 2018 Jun;81:1-9. doi: 10.1016/j.oraloncology.2018.04.007. Epub 2018 Apr 10.

Abstract

Objectives: Secondary oral squamous cell carcinoma (OSCC) is a late complication in allogeneic hematopoietic stem cell transplantation (HSCT) patients, but little is known about long-term outcomes and prognostication. Additionally, molecular alterations and immunologic insights unique to this disease remain largely unexplored.

Methods: We present a cohort of 31 patients with post-HSCT OSCC and reported on clinicopathologic predictors of survival. Whole-exome sequencing was performed on 6 (19%) matched pairs of peripheral blood (post-conditioning, pre-HSCT) and tumor samples. The entire cohort had archival tumor available for immunoprofiling with PD-1/L1 immunohistochemistry.

Results: Five-year overall survival (OS) was 57% (95% CI: 46.1-69.8) with a median disease-free survival (DFS) of 13.3 months. Advanced initial staging, a buccal or oral tongue subsite, chronic oral graft-versus-host disease (GVHD) and smoking all negatively impacted survival. High tumor mutational burden (TMB) (median 11.3 vs. 5.0) and unique mutational signatures were noted between unrelated and related donor groups - with a strong correlation between infiltrating PD-1+ lymphocytes and TMB (R = 0.98, p < 0.01). Some differences were observed when comparing commonly mutated genes among our cohort and TCGA, with a predominance of TP53 events.

Conclusion: Survival outcomes appear similar in HSCT survivors with OSCC compared with non-HSCT OSCC populations. We identified somatic alterations in genes with therapeutic potential unique to this subpopulation of oral cancers.

Keywords: Bone marrow transplantation; Genomics; Immunology; Oral cancer; Outcomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Female
  • Genomics*
  • Hematopoietic Stem Cell Transplantation*
  • Humans
  • Jagged-2 Protein / genetics
  • Male
  • Middle Aged
  • Mouth Neoplasms / genetics*
  • Mouth Neoplasms / therapy
  • Mutation
  • Survival Analysis
  • Survivors*
  • Young Adult

Substances

  • JAG2 protein, human
  • Jagged-2 Protein