RT Journal Article SR Electronic T1 HiLDA: a statistical approach to investigate differences in mutational signatures JF bioRxiv FD Cold Spring Harbor Laboratory SP 577452 DO 10.1101/577452 A1 Zhi Yang A1 Priyatama Pandey A1 Darryl Shibata A1 David V. Conti A1 Paul Marjoram A1 Kimberly D. Siegmund YR 2019 UL http://biorxiv.org/content/early/2019/03/15/577452.abstract AB We propose a hierarchical latent Dirichlet allocation model (HiLDA) for characterizing somatic mutation data in cancer. The method allows us to infer mutational patterns and their relative frequencies in a set of tumor mutational catalogs and to compare the estimated frequencies between tumor sets. We apply our method to somatic mutations in colon cancer with mutations classified by the time of occurrence, before or after tumor initiation. Applying the methods to 16 colon cancers, we found significant associations between the relative frequencies of mutational patterns and the time of occurrence of mutations. Our novel method provides higher statistical power for detecting differences in mutational signatures.