A case-control study comprised 177 patients with Various types of thyr
oid cancer and the same number of hospital controls individually match
ed by age, sex and place of residence. Malignant tumors were more freq
uent among first and second degree relatives of cases as compared to c
ontrols. The odds ratio (95% confidence interval) was 2.43 (1.33-4.44)
and 5.33 (1.77-16.01) respectively. The most frequent were cancers of
uterus and stomach with odds ratio of 6.00 (1.61-22.36) and 9.00 (1.6
4-49.35). Thyroid cancer was present only in first-degree relatives of
two cases and none of controls.