Every type of cancer is different, and has a unique set of symptoms associated with it. Some cancer symptoms are manifest outwardly, and are relatively easy to notice and identify (such as a lump in the breast for breast cancer, or blood in the stool corresponding to colorectal cancer). Other symptoms are observable, but harder to decipher. For instance, two of the major symptoms for lung cancer are a bronchitis-like deep cough and excessive shortness of breath. Few people would assume these symptoms were serious and fewer would associate them with cancer. Still other forms of cancer produce no observable symptoms until they are at a very advanced (and therefore hard to treat) stage. Specific symptom detail for cancer subtypes is provided in our cancer subtype documents.
A physician who suspects a patient may have a specific form of cancer will perform a series of tests and procedures to diagnose (or rule-out) a cancer. Commonly, doctors will collect a sample of tissue or fluid from the area believed to contain a cancerous tumor so that it may be analyzed in the laboratory under a microscope. This collection and observation procedure is known as a biopsy. Often, performing a biopsy and analyzing the resulting samples is the only way that doctors can accurately determine a diagnosis of cancer. Specific detail concerning diagnostic methods is provided in our cancer subtype documents.