Does anyone know if it is possible to perform B-allele frequency / LOH analysis on tumour only samples? (i.e. no matched normal controls samples).

I was reading CNVkit documentation and it states: "If you have no matched normal sample for a given tumor, you can use 1000 Genomes common SNP sites to extract the likely germline SNVs from a tumor-only VCF, and use just those sites with THetA2 (or another tool like PyClone or BubbleTree)."

But, as far as I'm aware, all of these require a matched normal control??