▁ 2 0 1 8 , ▁Lee ▁extended ▁his ▁own ▁record ▁at ▁the ▁Malays ia ▁Open , ▁taking ▁a ▁ 1 2 th ▁title ▁in ▁his ▁ 1 4 th ▁final , ▁and ▁reached ▁the ▁semi - final s ▁of ▁the ▁Indones ia ▁Open . ▁A ▁week ▁before ▁the ▁World ▁Championships , ▁the ▁Bad m inton ▁Association ▁of ▁Malays ia ▁( B AM ) ▁announced ▁that ▁Lee ▁would ▁not ▁be ▁able ▁to ▁take ▁part ▁in ▁the ▁champion ships ▁and ▁also ▁the ▁Asian ▁Games ▁as ▁he ▁has ▁to ▁under go ▁treatment ▁for ▁a ▁resp ir atory - related ▁dis order . ▁His ▁participation ▁in ▁these ▁two ▁tournament s ▁was ▁in ▁doubt ▁even ▁before ▁the ▁announ cement ▁after ▁media ▁reported ▁that ▁he ▁was ▁absent ▁from ▁the ▁training . ▁He ▁was ▁diagn osed ▁with ▁early ▁stage ▁of ▁nas oph ary nx ▁cancer ▁and ▁received ▁treatment ▁in ▁Taiwan . ▁ ▁Ret irement ▁On ▁ 1 3 ▁June ▁ 2 0 1 9 , ▁Lee ▁announced ▁his ▁ret irement ▁after ▁almost ▁a ▁year ▁since ▁he ▁was ▁diagn osed ▁with ▁nose ▁cancer ▁and ▁failed ▁to ▁return ▁to ▁competition ▁despite ▁dro pping ▁several ▁hints ▁that ▁he ▁would ▁make ▁a ▁return ▁in ▁early ▁ 2 0 1 9 . ▁This ▁ended ▁his ▁ 1 9 ▁year - long ▁international ▁bad m inton ▁career . ▁The ▁ret irement ▁came ▁under ▁his ▁doctor ' s ▁advice ▁to ▁avoid ▁high - int ens ity ▁training ▁to ▁avoid ▁a ▁re lapse ▁of ▁his ▁cancer . ▁ ▁M embers ▁of ▁the ▁media ▁and ▁players ▁al ike