Increased incidence of cancer in patients with cartilage-hair hypoplasia

Objective: Previous reports have suggested an increased risk of cancer amon g patients with cartilage-hair hypoplasia (CHH). This study was carr;ed out to further evaluate this risk among patients with CHH and their first-degr ee relatives. Study design: One hundred twenty-two patients with CHH were identified thro ugh 2 countrywide epidemiologic surveys in 1974 and in 1986. Their parents and nonaffected siblings were identified through the Population Register Ce nter. This cohort underwent follow-up for cancer incidence through the Finn ish Cancer Registry to the end of 1995. Results: A statistically significant excess risk of cancer was seen among t he patients with CHH (standardized incidence ratio 6.9, 95% confidence inte rval 2.3 to 16), which was mainly attributable to non-Hodgkin's lymphoma (s tandardized incidence ratio 90, 95% confidence interval 18 to 264). In addi tion, a significant excess risk of basal cell carcinoma was seen (standardi zed incidence ratio 35, 95% confidence interval 7.2 to 102). The cancer inc idence among the siblings or the parents did not differ from the average ca ncer incidence in the Finnish population. Conclusions: This study confirms an increased risk of cancer, especially no n-Hodgkin's lymphoma, probably attributable to defective immunity among pat ients with CHH.