[Long-term investigation of the risk of malignant diseases following intravenous radium-224 treatment for ankylosing spondylitis]. / Langzeituntersuchung zum Risiko maligner Erkrankungen nach intravenöser Behandlung des Morbus Bechterew mit Radium-224.

BACKGROUND AND PURPOSE: In German-speaking countries, the intravenous treatment of ankylosing spondylitis (AS) with radium-224 ((224)Ra) was common between the late 1940s and 2005. In this long-term investigation, the risk of malignant diseases following intravenous (224)Ra treatment for AS was assessed. PATIENTS AND METHODS: In a prospective long-term study, 1,471 patients with AS who were treated with (224)Ra between 1948 and 1975 have been followed together with a control group of 1,324 AS patients treated neither with radioactive drugs nor with X-rays. Standardized questionnaires to evaluate the patients' health status were used. Observed numbers of malignant diseases were compared with those of the control group as well as with expected numbers for a normal population. RESULTS: After 26 years of follow-up, causes of death have been certified for 1,006 patients of the exposure group (control group: 1,072 patients). Significantly increased rates of myeloid leukemia (12 cases observed vs. 2.9 expected; p < 0.001), kidney cancer (18 vs. 9.1; p < 0.01), thyroid cancer (4 vs. 1.2; p = 0.03) and borderline significantly increased rates of cancer of female genital organs (10 vs. 5.6; p = 0.06) were found in the exposure group in contrast to no significant increases of these diseases in the control group. Rates of pulmonary and gastrointestinal malignancies were not increased. Lymphatic leukemia (exposure group: 8 vs. 2.7; p < 0.01; control group: 7 vs. 3; p = 0.03) was significantly elevated due to a high rate of chronic lymphatic leukemia in both, the exposure as well as the control group. CONCLUSION: Treatment of AS with (224)Ra led to increased incidences of myeloid leukemia and malignancies of kidneys, thyroid and female genital organs. Although this kind of therapy is now abandoned, there is a need for close follow-up of patients who received it.

Incidence of leukaemia and other malignant diseases following injections of the short-lived alpha-emitter 224Ra into man.

We performed an epidemiological study on 1,471 ankylosing spondylitis patients treated with repeated intravenous injections of the short lived alpha-emitter (224)Ra (excluding radiation therapy with X-rays) between 1948 and 1975. These patients have been followed together with a control group of 1,324 ankylosing spondylitis patients treated neither with radioactive drugs nor with X-rays. The mean follow-up time was 26.3 years in the exposed and 24.6 years in the control group. To date, causes of death have been ascertained for 1,006 exposed patients and 1,072 controls. Special emphasis was placed on the reporting of malignant diseases. Expected numbers of cases were computed for the age, sex and calendar year distribution of both groups using cancer registry incidence rates. In the exposed group 18 cases of kidney cancer (vs. 9.1 cases expected, P < 0.01) and 4 malignant thyroid tumours (vs. 1.2 cases expected, P = 0.03) were observed. In the control group the observed cases for these tumours were not significantly elevated. The most striking observation, however, were the 21 cases of leukaemia in the exposed group (vs. 6.8 cases expected, P < 0.001) compared to 12 cases of leukaemia in the control group (vs. 7.5 cases expected). Further sub-classification of the leukaemias demonstrated a high increase of myeloid leukaemia in the exposed group (12 cases observed vs. 2.9 cases expected, P < 0.001), and out of these, especially a high excess of acute myeloid leukaemias (7 cases observed vs. 1.8 expected, P = 0.003). In the controls the observed cases are within the expected range (4 myeloid leukaemias vs. 3.1 cases). This increase in total leukaemias as well as particularly in myeloid leukaemias is significant in direct comparison between the exposed and control groups too (P < 0.05). The enhanced leukaemia incidence in the exposed group is in line with the observation of increased leukaemia incidence in mice injected with (224)Ra.