Patients with an ALK-related predisposition to neuroblastic tumors are at increased risk of developing the following neuroblastic tumors:
The risk of developing neuroblastic tumors is highest during infancy and decreases with increasing age. Tumors occur earlier (on average at 9 months of age) in cases of familial neuroblastoma compared with cases without a familial neuroblastoma predisposition (on average at 2-3 years of age).
In addition, there is a greater risk of developing multiple primary tumors in the case of familial neuroblastoma compared to the non-familial form. These multiple primary tumors may be bilateral adrenal gland tumors or tumors external to the adrenal glands that form in the region of sympathetic ganglia. Tumors may occur synchronously or metachronously.
The outcome of neuroblastic tumors is largely dependent on tumor type, tumor stage, and the effectiveness of therapy and less dependent on the presence of an ALK germline mutation.