Association of Thyroid Carcinoma with Malignant Lymphoma

Radiation-associated thyroid carcinoma is of clinical importancein modern radiation therapy of both Hodgkin's disease (HD) andnon-Hodgkin's lymphoma (NHL), because anatomically the thyroidis often in the radiation field. We have reviewed the recordsof HD and NHL patients seen at Roswell Park Memorial Institute(RPMI) between 1910 and 1960 to determine associated occurrenceof thyroid cancer. Radiation therapy was the major therapeuticmodality with the occasional use of single agent chemotherapywith nitrogen mustard, triethylene melamine (TEM), chlorambuciland prednisone. There were 519 patients with HD and 863 withNHL. The thyroid glands of 439 (84%) HD and 544 (63%) NHL patientswere included in the field of radiation. The mean age of patientswith HD was 39 yr while for those with NHL, it was 53 yr. Themean survival in HD was 4.2 yr and in NHL 3.8 yr. There werethree cases of thyroid cancer among the HD patients occurring31, 44 and 48 yr, respectively, after radiation therapy. Whencompared with the number of thyroid cancers expected to develop,the incidence was significantly greater (p < 0.005). In contrast,three NHL patients were found to have thyroid cancer at thetime of surgery or postmortem examination. This number is againgreater than expected in such a population (p < 0.005); however,in only two cases could the cancer be considered as a sequelato NHL treatment. In all three cases the cancer turned out tobe subclinical thyroid carcinoma, incidentally found at surgeryor autopsy. One of the patients is still alive without evidenceof either disease. The reason for this difference between patientswith HD and NHL treated with a similar principle is unclear.Some of the factors contributing to this difference may include:the younger age of HD patients at diagnosis; the longer survivalof patients with HD as compared with those with NHL; differencesin the sites of radiation and type of treatment given; and possibledifferences in immunological status between the two groups. ²Present addresses: 211 Owen Drive, Fayetteville, North Carolina,28304, U.S.A. ⁴Present addresses: 212 West 18th Street, Hopkinsville, Kentucky,42240, U.S.A. ⁵Present addresses: St. Francis Hospital, Park Avenue, Memphis,Tennessee, 38119, U.S.A ⁷Present addresses: Vassar Brothers Hospital, Poughkeepsie,NewYork, 12601, U.S.A.