Sir I have been a heavy smoker and drinker and also suffering from anxiety and depression.from last 2 weeks I started having pain in upper back .the pain increases at night if I continuously lie down on my back.i sleep for almost 10 hours a day with zero physical activity.my office work is also sitting at one place.occasionaly there is light pain on left side of abdomen..is this early warning of cancer..what tests should I undergo..please advice..