Intratumor heterogeneity and branched evolution revealed by multiregion sequencingIntratumor heterogeneity and branched evolution revealed by multiregion sequencingGerlinger M, Rowan AJ, Horswell S, Larkin J, Endesfelder D, Gronroos E, Martinez P, Matthews N, Stewart A, Tarpey P, Varela I, Phillimore B, Begum S, McDonald NQ, Butler A, Jones D, Raine K, Latimer C, Santos CR, Nohadani M, Eklund AC, Spencer-Dene B,2012-03-07T23:00:00Z<p style="text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2"><strong>​Abstract</strong><br></span></p><h2 class="a-article-h2 f-h12" style="box-sizing:inherit;margin:20px 0px -3px;padding:3px 0px 0px;border:0px;background-color:transparent;font-weight:700;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;text-transform:uppercase;letter-spacing:0.12em;color:#1a1a1a;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">BACKGROUND</span></h2><p class="f-body" style="box-sizing:inherit;margin-bottom:-2px;padding:2px 0px 0px;border:0px;background-color:transparent;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;color:#4d4d4d;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">Intratumor heterogeneity may foster tumor evolution and adaptation and hinder personalized-medicine strategies that depend on results from single tumor-biopsy samples.</span></p><h2 class="a-article-h2 f-h12" style="box-sizing:inherit;margin:20px 0px -3px;padding:3px 0px 0px;border:0px;background-color:transparent;font-weight:700;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;text-transform:uppercase;letter-spacing:0.12em;color:#1a1a1a;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">METHODS</span></h2><p class="f-body" style="box-sizing:inherit;margin-bottom:-2px;padding:2px 0px 0px;border:0px;background-color:transparent;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;color:#4d4d4d;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">To examine intratumor heterogeneity, we performed exome sequencing, chromosome aberration analysis, and ploidy profiling on multiple spatially separated samples obtained from primary renal carcinomas and associated metastatic sites. We characterized the consequences of intratumor heterogeneity using immunohistochemical analysis, mutation functional analysis, and profiling of messenger RNA expression.</span></p><h2 class="a-article-h2 f-h12" style="box-sizing:inherit;margin:20px 0px -3px;padding:3px 0px 0px;border:0px;background-color:transparent;font-weight:700;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;text-transform:uppercase;letter-spacing:0.12em;color:#1a1a1a;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">RESULTS</span></h2><p class="f-body" style="box-sizing:inherit;margin-bottom:-2px;padding:2px 0px 0px;border:0px;background-color:transparent;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;color:#4d4d4d;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">Phylogenetic reconstruction revealed branched evolutionary tumor growth, with 63 to 69% of all somatic mutations not detectable across every tumor region. Intratumor heterogeneity was observed for a mutation within an autoinhibitory domain of the mammalian target of rapamycin (mTOR) kinase, correlating with S6 and 4EBP phosphorylation in vivo and constitutive activation of mTOR kinase activity in vitro. Mutational intratumor heterogeneity was seen for multiple tumor-suppressor genes converging on loss of function; <span style="box-sizing:inherit;font-style:italic;margin:0px;padding:0px;border:0px;background-color:transparent;font-stretch:inherit;line-height:inherit;vertical-align:baseline;outline:0px;">SETD2, PTEN,</span> and <span style="box-sizing:inherit;font-style:italic;margin:0px;padding:0px;border:0px;background-color:transparent;font-stretch:inherit;line-height:inherit;vertical-align:baseline;outline:0px;">KDM5C</span> underwent multiple distinct and spatially separated inactivating mutations within a single tumor, suggesting convergent phenotypic evolution. Gene-expression signatures of good and poor prognosis were detected in different regions of the same tumor. Allelic composition and ploidy profiling analysis revealed extensive intratumor heterogeneity, with 26 of 30 tumor samples from four tumors harboring divergent allelic-imbalance profiles and with ploidy heterogeneity in two of four tumors.</span></p><h2 class="a-article-h2 f-h12" style="box-sizing:inherit;margin:20px 0px -3px;padding:3px 0px 0px;border:0px;background-color:transparent;font-weight:700;font-stretch:inherit;line-height:28px;vertical-align:baseline;outline:0px;text-transform:uppercase;letter-spacing:0.12em;color:#1a1a1a;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">CONCLUSIONS</span></h2><p class="f-body" style="box-sizing:inherit;margin-bottom:-2px;padding:2px 0px 0px;border:0px;background-color:transparent;font-family:ff-quadraat-web-pro, "times new roman", serif;font-stretch:inherit;line-height:28px;font-size:1.1875rem;vertical-align:baseline;outline:0px;color:#4d4d4d;text-align:justify;"><span class="ms-rteThemeFontFace-1 ms-rteFontSize-2">Intratumor heterogeneity can lead to underestimation of the tumor genomics landscape portrayed from single tumor-biopsy samples and may present major challenges to personalized-medicine and biomarker development. Intratumor heterogeneity, associated with heterogeneous protein function, may foster tumor adaptation and therapeutic failure through Darwinian selection. (Funded by the Medical Research Council and others.)</span><br></p><p><a href="https://www.nejm.org/doi/full/10.1056/NEJMoa1113205"><span class="ms-rteFontSize-2 ms-rteThemeFontFace-1">N Engl J Med (2012) 366:883-892.</span></a><br class="ms-rteFontSize-2 ms-rteThemeFontFace-1"></p><p><span class="ms-rteFontSize-2 ms-rteThemeFontFace-1" style="color:#666666;background-color:#ffffff;">DOI: 10.1056/NEJMoa1113205</span><br></p>201