King Charles has left his elder son Prince William and beloved daughter-in-law Kate Middleton ‘worried’ as the monarch is still undergoing cancer treatment.According to a report by the Radar Online, King Charles is still undergoing treatment after more than a year following his cancer diagnosis last year.The King was briefly hospitalized in March this year due to what the Palace called “temporary side effects.”The next month, the monarch confessed his diagnosis has been “a daunting and at times frightening experience.”Despite all this, King Charles has insisted on doing as much as he can, making public appearances and performing state duties amid his health setbacks.