About 22,000 new cases of malignant lymphoma will be diagnosed in the United States this year, and there will be 17,000 deaths. Lymphomas are cancers of the part of the circulatory system that plays a major role in a person's ability to fight infection. The lymph system consists mainly of lymph nodes, vessels and ducts, spleen, bone marrow, and thymus gland.
Lymphomas, such as Hodgkin's disease, strike more men than women; they claim 17,000 lives annually in the United States.
The most common lymphomas are reticulum cell sarcoma, lymphosarcoma, and Hodgkin's disease; they affect more men than women, and are frequently first detected by the presence of enlarged painless lymph nodes in the neck or groin. Some lymphoma patients can lead normal lives for many years. Hodgkin's disease, which differs in several respects from other lymphomas, is described on page 42.
Supervoltage radiotherapy is usually the treatment of choice for lymphomas in early, localized stages. Unfortunately, a majority of patients have advanced disease when lymphoma is first detected. For these patients, chemotherapy is frequently the primary treatment.
In lymphosarcoma the following drugs have proved helpful in many cases during the past 20 years: nitrogen mustard, chlorambucil, cyclophosphamide, thioTEPA, and TEM; the adrenal cortical compounds; and vinblastine and vincristine.
In April 1968 an evaluation of combination chemotherapy in 52 adults with lymphosarcoma and 36 with reticulum cell sarcoma was reported. Patients in advanced stages of disease previously untreated by chemotherapy were given a combination of cyclophosphamide, vincristine, and prednisone in either high doses or low doses. Another group of the patients was treated only with cyclophosphamide.
In lymphosarcoma, the high- and low-dose regimens of drug combinations produced remissions in 100 percent and 90 percent of the patients, respectively; cyclophosphamide produced remission only in 40 percent. In reticulum cell sarcoma the results were less striking: 85 percent and 61 percent achieved remissions from the high- and low-dose combinations; 50 percent of those receiving the single drug alone had a remission. The low-dose combination was least toxic.
Also, in April 1968 scientists reported on the treatment of childhood lymphosarcoma and reticulum cell sarcoma with methotrexate given in high doses in an intermittent schedule. The drug was "pulsed" in 4-hour continuous infusions at intervals ranging from one day to 28 days according to response and toxicity. In some patients citrovorum factor, a methotrexate antagonist, was given to reduce toxicity. Complete resolution of local tumor was a-chieved in 7 of 8 children with lymphosarcoma and 3 of 5 children with reticulum cell sarcoma.
It is hoped that combined radiotherapy and chemotherapy may offer better results than either method alone, and that drug treatment may make patients more susceptible to curative treatment with irradiation.