The next Institute Seminar will take place Wednesday 7th of February at 12:00 in the auditorium in the Research Building, Montebello.
Marthe Løvf (Molecular Oncology) will present:
High degree of genomic heterogeneity in multifocal primary prostate cancer
The Institute Seminar overview for the spring season of 2018 is now ready.
Background: Most primary prostate cancers are multifocal with individual tumors harboring different aggressiveness, but the intra- and interfocal genomic heterogeneity among these tumors are still poorly understood.
Objective: To determine the heterogeneity of somatic gene mutations in multifocal prostate cancer.
Design, Setting, and Participants: We performed high-coverage whole-exome sequencing of 153 samples, taken from 2-3 distinct tumor foci and one non-cancerous prostate tissue sample from each of 41 patients, covering a total of 89 tumor foci.
Results and Limitations: We identified altogether 4084 somatic mutations, and found a very high degree of interfocal heterogeneity among these tumors. That is, 76 % of pairwise compared tumor foci from the same prostatectomy specimen had no point mutations in common and DNA copy number changes were rarely shared across cancer foci. Also, in the remaining 24 % of the pairwise compared tumor foci, 98 % of the somatic mutations were entirely specific to one of the foci. The few alterations shared across tumor foci were seldom in cancer-critical genes.
Conclusions: Different tumor foci within the same patient do not share the same somatic gene mutations and are likely activated by different driver alterations. This will have major impact on the implementation of genome-based personalized prostate cancer medicine as it will be necessary to take information from all tumor foci into account.