In addition, 45% of the BSCs harbor recurrent mutations in the SWI/SNF complex gene, ARID1A, and evolutionary analysis revealed that ARID1A mutations occur after PTCH1 but before SCC driver mutations, indicating that ARID1A mutations may bestow plasticity enabling squamatization.
These findings suggest that 2 genes of loss, CDKN2B and PTCH1, are associated with poor overall survival in patients with SCC of the lung and may be useful as prognostic markers.
Squamous cell carcinomas (SCCs) of the skin display allelic loss in this chromosomal region, which, in addition to the PTCH gene, contains the DNA repair gene xeroderma pigmentosum complementation group A (XPA).
Our results suggest that inactivation of some tumor suppressor gene(s) on 9q other than PTC contributes to the development of squamous cell carcinomas in these tissues.