Cancer in dyskeratosis congenita

Abstract

Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome. The spectrum of cancer susceptibility in this disorder of telomere biology has not been described. There were more than 500 cases of DC reported in the literature from 1910 to 2008; the National Cancer Institute (NCI) prospective DC cohort enrolled 50 cases from 2002 to 2007. Sixty cancers were reported in 52 literature cases, while 7 occurred among patients in the NCI DC cohort. The 2 cohorts were comparable in their median overall survival (42 years) and cumulative incidence of cancer (40%-50% by age 50 years). The most frequent solid tumors were head and neck squamous cell carcinomas (40% of patients in either cohort), followed by skin and anorectal cancer. The ratio of observed to expected cancers (O/E ratio) in the NCI cohort was 11-fold compared with the general population (P < .05). Significantly elevated O/E ratios were 1154 for tongue cancer and 195 for acute myeloid leukemia. Survival after bone marrow transplantation for aplastic anemia or leukemia was poor in both cohorts. The frequency and types of cancer in DC are surpassed only by those in Fanconi anemia (FA), indicating that FA and DC have similarly high risks of adverse hematologic and neoplastic events, and patients with these diseases should be counseled and monitored similarly.

Figure 1

Cumulative survival in cases with dyskeratosis congenita, calculated using the method of Kaplan and Meier. (A) Cases reported in the literature through 2008, N = 552. (B) Cases enrolled in the NCI IBMFS DC cohort through 2007, N = 50. Data are the cumulative number of patients surviving, censored for age last known while alive. Insets show the survival curves for those with (solid red) and without (dashed blue) cancer.

Figure 2

Cumulative incidence by age of development of cancer in cases with dyskeratosis congenita. (A) Cases reported in the literature through 2008, N = 52. (B) Cases enrolled in the NCI IBMFS DC cohort through 2007, N = 7. Data are the cumulative proportion experiencing each event as the cause of failure; shaded area is the 95% pointwise confidence envelope. Vertical lines indicate the age at which patients were censored with or without cancer.

Figure 3

Cumulative incidence by age of development of MDS in cases with dyskeratosis congenita. (A) Cases reported in the literature through 2008, N = 8. (B) Cases enrolled in the NCI IBMFS DC cohort through 2007, N = 5. Data are the cumulative proportion experiencing each event as the cause of failure; shaded area is the 95% pointwise confidence envelope. Vertical lines indicate the age at which patients were censored with or without MDS.

Figure 4

Cumulative survival in cases with dyskeratosis congenita after bone marrow transplantation, calculated using the method of Kaplan and Meier. (A) Cases reported in the literature through 2008, N = 65. (B) Cases enrolled in the NCI IBMFS DC cohort through 2007, N = 11. Data are the cumulative number of patients surviving, censored for last known age alive. Insets show the survival curves for those with sibling (dashed blue) and alternative (solid red) donors.