▁or ▁l ym ph at ics ▁from ▁a ▁primary ▁tum or ▁and ▁is ▁carried ▁around ▁the ▁body ▁in ▁the ▁blood ▁circul ation . ▁C TC s ▁can ▁extra vas ate ▁and ▁become ▁se eds ▁for ▁the ▁subsequent ▁growth ▁of ▁additional ▁tum ors ▁( met ast ases ) ▁in ▁distant ▁org ans , ▁a ▁mechanism ▁that ▁is ▁responsible ▁for ▁the ▁vast ▁majority ▁of ▁cancer - related ▁death s . ▁The ▁detection ▁and ▁analysis ▁of ▁C TC s ▁can ▁assist ▁early ▁patient ▁pro gn oses ▁and ▁determine ▁appropriate ▁tail ored ▁treat ments . ▁Currently , ▁there ▁is ▁one ▁F DA - appro ved ▁method ▁for ▁C TC ▁detection , ▁Cell Search , ▁which ▁is ▁used ▁to ▁diagn ose ▁breast , ▁col ore ct al ▁and ▁pro state ▁cancer . ▁ ▁The ▁detection ▁of ▁C TC s , ▁or ▁liquid ▁bi ops y , ▁presents ▁several ▁advantages ▁over ▁traditional ▁t issue ▁bi ops ies . ▁They ▁are ▁non - in vas ive , ▁can ▁be ▁used ▁repeatedly , ▁and ▁provide ▁more ▁useful ▁information ▁on ▁met ast atic ▁risk , ▁disease ▁pro gression , ▁and ▁treatment ▁effect iveness . ▁For ▁example , ▁analysis ▁of ▁blood ▁samples ▁from ▁cancer ▁patients ▁has ▁found ▁a ▁prop ens ity ▁for ▁increased ▁C TC ▁detection ▁as ▁the ▁disease ▁progress es . ▁Blood ▁tests ▁are ▁easy ▁and ▁safe ▁to ▁perform ▁and ▁multiple ▁samples ▁can ▁be ▁taken ▁over ▁time . ▁By ▁contrast , ▁analysis ▁of ▁solid ▁tum ors ▁necess it ates ▁invas ive ▁procedures ▁that ▁might ▁limit ▁patient ▁comp liance . ▁The ▁ability ▁to