Increased incidence of cancer in patients with cartilage-hair hypoplasia.

OBJECTIVE: Previous reports have suggested an increased risk of cancer among patients with cartilage-hair hypoplasia (CHH). This study was carried out to further evaluate this risk among patients with CHH and their first-degree relatives.

STUDY DESIGN: One hundred twenty-two patients with CHH were identified through 2 countrywide epidemiologic surveys in 1974 and in 1986. Their parents and nonaffected siblings were identified through the Population Register Center. This cohort underwent follow-up for cancer incidence through the Finnish Cancer Registry to the end of 1995.

RESULTS: A statistically significant excess risk of cancer was seen among the patients with CHH (standardized incidence ratio 6.9, 95% confidence interval 2.3 to 16), which was mainly attributable to non-Hodgkin's lymphoma (standardized incidence ratio 90, 95% confidence interval 18 to 264). In addition, a significant excess risk of basal cell carcinoma was seen (standardized incidence ratio 35, 95% confidence interval 7.2 to 102). The cancer incidence among the siblings or the parents did not differ from the average cancer incidence in the Finnish population.

CONCLUSIONS: This study confirms an increased risk of cancer, especially non-Hodgkin's lymphoma, probably attributable to defective immunity, among patients with CHH.