Dual cancers in Ataxia-Telangiectasia: a case report and literature review.

Background: Ataxia-telangiectasia (A-T) is a rare autosomal recessive disorder caused by mutations in the ATM gene, leading to defective DNA repair, genomic instability, and immune surveillance dysfunction. Therefore, A-T patients are predisposed to cancers, particularly hematological malignancies like lymphoma and leukemia.

Methods: To identify the characteristics of A-T cases with multiple cancers, we searched the Iranian A-T registry with 324 cases and conducted a systematic literature search in PubMed and Embase using appropriate keywords. Studies reporting A-T patients with two or more distinct cancers were included and compared with cases identified from our national registry.

Results: Multiple cancers were reported in one 19-year-old male with A-T who presented diffuse large B-cell lymphoma (DLBCL) and renal cell carcinoma (RCC) due to a homozygous severe splicing mutation in ATM. In our literature review, we found 14 cases of A-T patients diagnosed with at least two distinct types of cancer. Among the secondary cancers in the 14 patients, hematologic cancer was observed in 3 patients (21.4%), while non-hematologic cancers were seen in 11 patients (78.6%). Similar to our case, two A-T patients were diagnosed with RCC but only as a primary tumor.

Conclusion: The combination of hematological and solid tumors underscores the significance of cancer predisposition in A-T patients. Given their heightened cancer risk, A-T patients should benefit from regular cancer screening and tailored therapeutic approaches to minimize treatment-related complications.