Hi, Thanks for writing in. It is important to know proper details about cancer in your family and if any relatives had it. This will tell us if there is any increased risk of a particular cancer in you. Bodyache and soreness can be due to generalized weakness and anxiety. Cancer is not one condition but a group of many conditions involving uncontrolled proliferative cells in various organs. Your light headedness might also be due to anxiety. Highly suspicious common symptoms of cancer are a swelling that is painful or painless of recent appearance and growing fast, cough that cannot be explained, fever, loss of weight, generalized weakness, vomiting, blood in stools, sudden change in bowel habit. If you want to get peace of mind concerning you having cancer then please approach a cancer screening clinic at any cancer hospital and inform them about cancer history in your family and smoking history and get the important relevant cancer screening tests done.