Stages of cancer: they vary from one cancer type to another and according to the classification systems used but essentially, the less advanced the cancer, the lower the stage number diagnosed and the better the prognosis.

The stages quantify the development of the cancer in the body. It thus indicates the metastatic progression of the disease at the time of diagnostic. The stage is given in roman numbers (from stage I to stage IV), and is also based on the involvement of the cancer in the primary tumor, on its invasion to adjacent lymph nodes or to other part of the body. For example, in stage I disease, the cancer will still be localized inside the organ where it originated and will not have spread to adjacent lymph nodes or other organs. In contrast, in stage IV disease, cancer will have spread to either distant lymph nodes (far from the original cancer site) or to distant organs.

Studies have shown that specific survival rates are associated with each stage. For instance, while the 5-year relative survival rate for stage I could be close to 100 %, it could drop below 25 % for a stage IV disease.

A diagnosis is the process by which a disease, such as cancer, is identified from its signs and symptoms. Some tests or analysis are performed in order to identify or confirm the presence of a cancer. Such tests may include blood cell count, blood chemistry study, biopsy, etc. Some are external like mammograms, others such as biopsies require the removal of small amount of tissues for further analysis. Mammograms and colonoscopies are examples of diagnostic procedures.

After the diagnosis has been performed and the disease identified, it is possible to give the patient's chance of recovery. The prognosis therefore predicts the outcome of a disease like cancer and the possible evolution of the disease. Depending on various factors, such as the type of cancer, the age of the patient and the stage at which the disease has been diagnosed, the prognosis will vary.

References