What is staging? Why is it important?
After the diagnosis of systemic ALCL is confirmed, the extent of the disease is determined. This is called "staging." Staging is used to plan treatment and suggest the prognosis (long-term outcome).

In previous decades, patients required exploratory surgery to look for spread of disease in the abdomen. Chest x-rays were used to determine if lymphoma was present in the chest. Now, sophisticated scanning tools (CT scan or PET scan) can allow disease to be staged with increased accuracy in most patients. Surgical biopsy of suspicious findings on the scans may still be necessary.

Staging is further classified to indicate whether patients have symptoms (referred to as "B" symptoms) including weight loss of greater than 10% in the past 6 months, recurrent unexplained fever or drenching night sweats, and by the response to prior therapy. The more advanced the stage, the more aggressive the treatment necessary. The earlier the stage of disease, the higher the proportion of patients likely to experience long term cure with modern therapy.

The presence or absence of chromosomal changes, known as t(2;5) translocation, within the tumor cells also influences the clinical course of the disease. Younger patients' tumors tend to be ALK-positive while older patients tend to be ALK-negative. This information is a useful addition to classical staging information.

• With appropriate aggressive treatment, cures can be obtained. By combining high dose chemotherapy and a form of bone marrow transplantation known as ASCT, an overall 5 year survival rate of 87% has been reported. Many of these patients can expect to be cured.
• If first line treatment fails or if the disease relapses, further responses may be obtained with additional therapy; however, the chances of subsequent cure are reduced.
• A number of new therapies are currently in clinical trials for the treatment of ALCL.
• Untreated, the disease is usually progressive and fatal.