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
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.