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supplementary data including three tables and two figures can be found with this article online at http://www.genominfo.org/src/sm/gni-15-48-s001.pdf a list of non - silent somatic mutations identified in a breast tumor by wes a list of copy number alterations identified in a breast tumor by wes seventy - eight cancer genes for oncochase cancer panel analysis disease status at the time of cancer recurrence .
bone scan shows multiple bone metastases involving spine , sacrum and rib ( a ) .
chest computed tomography ( ct ) scan shows multiple lung metastases ( b ) , and abdomen ct scan reveals liver metastasis ( c ) .
progression of bone metastases involving whole spine , both femur shaft and pelvic bone was detected by bone scan ( a ) .
chest computed tomography ( ct ) scan shows progressive lung metastases ( b ) and abdomen ct scan shows progression of liver metastases ( c ) .
tumor tissues from biopsies or surgery are major sources for the next generation sequencing ( ngs ) study , but these procedures are invasive and have limitation to overcome intratumor heterogeneity . 
 recent studies have shown that driver alterations in tumor tissues can be detected by liquid biopsy which is a less invasive technique capable of both capturing the tumor heterogeneity and overcoming the difficulty in tissue sampling . however , it is still unclear whether the driver alterations in liquid biopsy can be detected by targeted ngs and how those related to the tissue biopsy . in this study , we performed whole - exome sequencing for a breast cancer tissue and identified pten p.h259fs*7 frameshift mutation . in the plasma dna ( liquid biopsy ) 
 analysis by targeted ngs , the same variant initially identified in the tumor tissue was also detected with low variant allele frequency . 
 this mutation was subsequently validated by digital polymerase chain reaction in liquid biopsy . 
 our result confirm that driver alterations identified in the tumor tissue were detected in liquid biopsy by targeted ngs as well , and suggest that a higher depth of sequencing coverage is needed for detection of genomic alterations in a liquid biopsy .