Genetic Predisposition to Numerous Large Ulcerating Basal Cell Carcinomas and Response to Immune Therapy.

Objective: Well-defined germ-line mutations in the gene are associated with syndromic multiple basal cell carcinomas (BCCs). Here, we used whole exome sequencing (WES) to identify the role of patched-1 in patients with multiple, unusually large BCCs.

Methods: A 72-year old patient presenting with numerous BCCs progressing to large ulcerating lesions was enrolled. WES was used to identify the pathogenic gene locus.

Results: Genetic work-up by WES identified a homozygous nonsense mutation in the tumor tissue but not present in her blood cells or in non-lesional skin. In addition, heterozygous missense mutations were identified in three cancer-associated genes (, and ) in blood cells as well as in lesional and non-lesional skin. We also tested systemic immune therapy as a potentially beneficial approach to treat patients with numerous large BCCs on scatted areas of involvement. A rapid and sustained response to nivolumab was noted, suggesting that it is an efficacious drug for long-term therapeutic outcome.

Conclusion: , , and may potentially contribute to the synergistic oncogene driven malignant transformation manifesting as multiple, unusually large BCCs.