Last week I tried to explain the very complex non-Hodgkin lymphomas (NHL). This week I want to cover Hodgkin’s lymphoma, more commonly known as Hodgkin’s Disease (HD). It gets its eponymous name from Dr. Thomas Hodgkin, who first described it in 1832.
Hodgkin’s is a potentially curable malignant lymphoma and carries a much better prognosis than non-Hodgkin lymphomas. It is a very specific type of lymphoma that is defined by its microscopic appearance and by specific proteins that are found on the cell membranes of the tumor cells.
The estimate for 2015 was that there would be 9,050 new cases of Hodgkin’s Disease (5,100 men and 3,950 women) and 1,150 deaths (660 men and 490 women). It is more common in whites and slightly more common in men, except in childhood where 85 percent of the cases are found in boys. The disease has what is called a bimodal age distribution, with occurrences between the ages of 15 and 34 or over age 55.
The cause of HD is unknown. It’s hypothesized that a viral infection, especially Epstein-Barr virus (EBV) may cause HD. This is the virus that causes mononucleosis (mono). EBV is found in half of HD tumors in people with normal immune systems and 100 percent of the time in people infected with HIV. One percent of people with HD have a family history of the disease. Siblings of a person with HD are about three to seven times more likely to develop HD themselves.
Symptoms of HD are very similar to those of non-Hodgkin lymphomas. About 40 percent of patients develop B Symptoms (weight loss, fever and drenching night sweats). Hodgkin's tumors are frequently found in the chest. Patients may therefore present with chest pain, cough and shortness of breath. Most patients present with enlarged lymph nodes in the neck (60-80 percent), armpits (6-20 percent) or, less commonly, the groin. Patients may also present with an enlarged liver or spleen.
The diagnosis of HD is made by doing blood work and radiologic studies. A definitive diagnosis of HD can only be made by removing involved lymph nodes for microscopic examination. A simple chest X-ray may show a tumor. If the diagnosis is suspected, a CT scan of the chest, abdomen and pelvis are usually ordered to look at the internal lymph nodes.
More recently, the standard test for diagnosis and staging is the PET/CT scan. PET stands for positron emission tomography. PET scanning is performed by tagging sugar molecules with a radioactive tracer. Since cancer cells have high metabolism, a lot of the sugar molecules are taken up by the cancerous cells and the radioactivity can be detected using a special camera. This information, combined with standard X-rays from the CT scan, is very specific for determining how extensive the HD is.
I mentioned “staging.” This is something that is done in cancers to describe how extensive the disease is. This is very important for determining treatment and prognosis. The staging of HD can be anywhere from stage I (found in one lymph node area) to stage IV (found in many areas or involving other organs or the bone marrow). The presence or absence of B symptoms is also part of the staging of HD. The five-year survival rate with stage I and II disease is about 90 percent, while stage III carries an 84 percent survival and stage IV roughly 65 percent. Those patients who have very large “bulky” disease, greater than three sites of involvement, B symptoms or disease outside the lymph nodes have a worse prognosis.
Hodgkin disease is considered curable. The goal of treatment is to induce a complete remission where there is no evidence of disease as evidenced by PET/CT, physical exam and lab studies. Treatment usually involves a combination of chemotherapy and radiation. These treatments can potentially cause long-term toxic effects on the body. Newer combinations of chemotherapy are much less toxic that those used a few years ago. Still, patients can develop heart disease, lung disease, thyroid problems and other cancers (lung, breast & leukemias) as a result of treatment. Reduced fertility is also a concern.
Dr. John Roberts is a Crawfordsville physician. His column is published weekly in The Paper and he has a daily health tip as well. Dr. Roberts is one of the owners of Sagamore News Media, the parent company of The Paper of Montgomery County.