Cancer of the ampulla of Vater: analysis of the whole genome sequence exposes a potential therapeutic vulnerability
Menée sur un patient atteint d'un cancer de l'ampoule de Vater, cette étude de séquençage du génome entier identifie la présence de mutations des gènes KRAS, SMAD4 et PTEN, suggérant la mise en oeuvre d'un traitement à base d'inhibiteurs de mTOR et PI3K
BACKGROUND:Recent advances in the treatment of cancer have focused on targeting genomic aberrations with selective therapeutic agents. In rare tumors, where large-scale clinical trials are daunting, this targeted genomic approach offers a new perspective and hope for improved treatments. Cancers of the ampulla of Vater are rare tumors that comprise only about 0.2% of gastrointestinal cancers. Consequently, they are often treated as either distal common bile duct or pancreatic cancers.METHODS:We analyzed a DNA from a resected cancer of the ampulla of Vater and whole blood DNA, from a 63 year-old man who underwent a pancreaticoduodenectomy, by whole genome sequencing achieving 37 and 40x coverage respectively. We determined somatic mutations and structural alterations.RESULTS:We identified relevant aberrations including deleterious mutations of KRAS and SMAD4 as well as a homozygous focal deletion of the PTEN tumor suppressor gene. These findings suggest that these tumors have a distinct oncogenesis than either common bile duct cancer or pancreatic cancer. Furthermore, this combination of genomic aberrations suggests a therapeutic context for dual mTOR/PI3K inhibition.CONCLUSIONS:Whole genome sequencing can elucidate an oncogenic context and expose potential therapeutic vulnerabilities in rare cancers.