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Lymphoma is a cancer of the lymph glands. Classification tells you what kind you have. Staging tells you where it is. Early diagnosis, classification and staging affect treatment and prognosis.
Non-Hodgkin lymphoma (NHL) is a very different cancer than those affecting a specific organ of the body – for example cancer of the prostate or lung. With NHL a blood cell called a lymphocyte, which normally fights infection, makes too many copies of itself. Since it's a blood cell it can go anywhere, so we see lymphomas in the blood, in the bone marrow, in lymph nodes, and in organs. It's also an extremely complicated disease – or more accurately, set of diseases. There are anywhere from 10 to 30 subtypes of NHL. Some are so aggressive that patients are immediately admitted to a hospital for treatment. Others are so indolent (slow progressing) that some patients never require therapy at all.1
NHL's ability to appear almost anywhere in the body and its complexity make it challenging to diagnose. Yet, a precise diagnosis is particularly critical for NHL patients to give them best chance of not being over- or under-treated, and of being cured.
The process of diagnosis starts in the usual way – with a medical history and physical exam. The doctor feels the lymph nodes to see if they are swollen and if so, assess the texture of the swelling. Blood tests are used to rule out infection and other diseases. Imaging studies range from simple X-rays to CT Scans, MRIs and PET scans. The definitive test for diagnosing NHL is a biopsy. Most often, a surgical biopsy is needed to remove a lymph node. The tissue is studied by a pathologist and if cancer is present, it will be classified, graded and staged.
Lymphomas can be classified and graded by whether they are:
- B- or T-cell lymphomas. B-cell lymphomas make up most (about 85%) of non-Hodgkin lymphomas in the United States.2 The B- or T-cells are further subdivided by whether they were derived from immature or mature cells and then by their appearance, genetic make-up, and specific chemical markers.
- Indolent (slow progressing) or aggressive (fast progressing).
- Patients with indolent lymphomas can live many years before the disease poses a risk. They often go into remission for long periods, but they usually relapse. The majority of the non-Hodgkin lymphomas are indolent.
- Aggressive lymphomas are more likely to cause rapid death, but with aggressive treatment they are more likely to be cured than indolent lymphomas.
- The range from indolent disease to aggressive disease does not fall into discrete categories, but is instead a continuum.3 In general, predicting the outcome for indolent lymphomas is more difficult than for aggressive lymphomas.
The next step is to sort the disease by stage. The stage of an NHL is determined by the number of tumors and whether they are still localized or have spread beyond the lymph node. Staging may involve one or more of the following tests: bone marrow biopsy, CT scan, MRI, ultrasound, spinal tap and PET scan.
The Ann Arbor Staging System is the most popular system for classifying NHL.4
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Stage I: |
NHL is limited to one lymph node group (e.g., neck, underarm, groin, etc.) above or below the diaphragm, or NHL is in an organ or site other than the lymph nodes (extranodal) but has not spread to other organs or lymph nodes. |
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Stage II: |
NHL is limited to two lymph node groups on the same side of the diaphragm, or NHL is limited to one extranodal organ and has spread to one or more lymph node groups on the same side of the diaphragm. |
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Stage III: |
NHL is in two lymph node groups, with/without partial involvement of an extranodal organ or site above and below the diaphragm. |
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Stage IV: |
NHL is extensive (diffuse) in one organ or site, with/without NHL in distant lymph nodes. |
Most NHL is already in Stage III or IV when it's diagnosed. For some cancers, that would be a bad prognosis. But many non-Hodgkin lymphomas are curable at that stage, depending on the subtype.5
An accurate diagnosis is essential to predict how NHL will progress and to individualize treatment. Lymphoma responds to very different forms of treatment than other cancers and there are distinct differences in NHL subtypes as well.
1 Jonathan Friedberg, M.D., University of Rochester Medical Center, on www.patientpower.info
2 American Cancer Society
3 Non-Hodgkin's Lymphomas: Making Sense of Diagnosis, Treatment, and Options, by Lorraine Johnston
4 www.oncologychannel.com/
5 Dr. John P. Leonard, Weill Cornell Medical College/New York-Presbyterian Hospital, Many Options, but Little Consensus,The New York Times, September 9, 2008
Learn more about non-Hodgkin lymphoma:
Key Point 2: The treatments for non-Hodgkin lymphoma are effective and improving. People can live long, productive lives with correct treatment.
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