What are the core symptoms of cancer?

Almost anything: Any symptom can have a whole range of causes. These causes generally fall into certain categories. Only one of these categories is cancer.

Varies with type: Cancer is many different illnesses and the core symptoms vary with the organ affected and the type of cancer. The following are some of the core symptoms: lump in an organ, weight loss, blood in stool, urine or sputum, cough, tiredness, vague abdominal symptoms including pain, unexplained infections, persistent headache, change in bowel habits, irregular menses etc.