Depends on organ. That depends greatly on the organ. For lungs, many times there are no symptoms. For breast cancer, sometimes you can feel a lump or have bloody discharge from the nipple. For kidney cancer, maybe you will have blood in the urine. If anything is just not right, go see a doctor. And also make sure you get your age appropriate screening tests as well, with which your doctor can help as well.
Organ-Dependent. The symptoms associated with cancer are heavily dependent upon which organ the cancer originated in. For example, colon cancer may cause intestinal blockage or blood within bowel movements, whereas lung cancer may cause bloody sputum. The common denominator with any cancer's symptoms is to be attuned to your body: anything new and different warrants a visit to your doctor.