Congenital IGF1 deficiency tends to confer protection against post-natal development of malignancies.

Objective: To investigate whether congenital IGF1 deficiency confers protection against development of malignancies, by comparing the prevalence of malignancies in patients with congenital (secondary) deficiency of IGF1 with the prevalence of cancer in their family members.

Method: Only patients with an ascertained diagnosis of either Laron syndrome (LS), congenital IGHD, congenital multiple pituitary hormone deficiency (cMPHD) including GH or GHRHR defect were included in this study. In addition to our own patients, we performed a worldwide survey and collected data on a total of 538 patients, 752 of their first-degree family members, of which 274 were siblings and 131 were further family members.

Results: We found that none of the 230 LS patients developed cancer and that only 1 out of 116 patients with congenital IGHD, also suffering from xeroderma pigmentosum, had a malignancy. Out of 79 patients with GHRHR defects and out of 113 patients with congenital MPHD, we found three patients with cancer in each group. Among the first-degree family members (most heterozygotes) of LS, IGHD and MPHD, we found 30 cases of cancer and 1 suspected. In addition, 31 malignancies were reported among 131 further relatives.

Conclusions: Our findings bear heavily on the relationship between GH/IGF1 and cancer. Homozygous patients with congenital IGF1 deficiency and insensitivity to GH such as LS seem protected from future cancer development, even if treated by IGF1. Patients with congenital IGHD also seem protected.