I am a male, age 73, former smoker, and currently a semi-heavy drinker. Within the past year I have lost 25 pounds (unintentional). Recently I have had intermittent diarrhea, loss of appetite and fatigue. I have polycythemia vera which my current doctor keeps an eye on. I have recently had an upper and lower endoscopy which shows everything is normal. Is there a chance I have cancer?