Quality of life of patients with cancer attending outpatient clinics at the King Abdulaziz Medical City, Riyadh, Saudi Arabia oleh Sultan Mohammed Alshehri, Abdulrhman Faeq Alzamil, Rayan Ibrahim Alturki, Humoud Auoad Alhoraim, Riyadh Ali Alghamdi, Mohammed Salman Almutairi, Emad Mohammad Masuadi, Abdullah Mohammed Algarni