Does yttrium radiosynovectomy increase the risk of cancer in patients with rheumatoid arthritis?
OBJECTIVE
To study the long term risk of cancer in patients with rheumatoid arthritis (RA) who have been treated with yttrium.


METHODS
The medical record numbers of 1228 patients with RA who were admitted to hospital in 1979-85 were identified in the database of Jyväskylä Central Hospital. Radiosynovectomy of the knee joint was performed in a total of 143 patients using yttrium-90 silicate during the years 1970-85, while 1075 did not receive yttrium radiosynovectomy; 10 received yttrium treatment later than 1985 and were excluded from the analysis. The Finnish Cancer Registry database was used to examine whether the subjects had cancer during the follow up from 1979 until the end of 1999.


RESULTS
Nine cases of cancer were found among the patients who had received yttrium, whereas the expected number based on the incidence among the population in the region was 14.9. The standardised incidence ratio of cancer was 0.6 (95% confidence interval (CI) 0.3 to 1.1) for the patients who received yttrium, and 1.1 (95% CI 0.9 to 1.3) for the patients who did not receive yttrium.


CONCLUSIONS
Yttrium treatment did not increase the risk of cancer.
Vuorela
J
J
Hospital Physics, Jyväskylä Central Hospital, Jyväskylä, Finland.
Sokka
T
T
Pukkala
E
E
Hannonen
P
P
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000532:radiotherapy*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D012307:Risk Factors; D013583:Synovial Membrane / Q000528:radiation effects*; D015021:Yttrium Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use
D015021:Yttrium Radioisotopes