Do ataxia telangiectasia patients have risk of developing cancer?

Yes. Overall, the risk of an ataxia telangiectasia (A-T) patient developing any cancer is 37-fold higher than individuals in the general population. The risk of developing lymphoid tumors, however, the most frequently diagnosed cancers in A-T patients, is 100-fold higher than in the general population; A-T patients have about a 10 percent risk of developing lymphoma or leukemia. Cancers also occur in the stomach, brain, ovary, skin, liver, larynx, parotid gland, and breast.

This answer is based on source information from the National Cancer Institute.