Table 1: PIK3CA mutations in bone metastasis samples.

Case Bone marrow aspirate status Bone marrow trephine biopsy status CT-guided bone metastasis biopsy status Primary tumour status 1 neg. nd neg. nd neg. nd no nd 2 pos. E545K pos. E545K pos. E545K yes E545K 3 neg. nd pos. WT pos. WT yes WT 4 neg. nd pos. H1047R nd nd yes H1047R 5 nd nd neg. nd neg. nd no nd 6 neg. nd neg. nd nd nd no nd 7 neg. nd neg. nd neg. nd no nd 8 neg. nd neg. nd neg. nd no nd 9 neg. nd neg. nd neg. nd no nd 10 neg. nd neg. nd nd nd no nd 11 neg. nd pos. WT nd nd no nd 12 neg. nd nd nd pos. H1047R hom. no nd 13 pos. WT pos WT pos. neg. yes WT 14 neg. nd neg. nd nd nd no nd

For aspirate, trephine biopsy and CT-guided biopsy, negative (neg.) or positive (pos.), indicate whether or not tumour cells were present in the biopsy. “nd” indicates when a biopsy procedure or an assay was not performed. WT indicates wild-type sequence at hotspot mutation sites; H1047R and E545K indicate mutations. H1047R hom. indicates that this mutation appeared to be homozygous in this patient (all other mutations were heterozygous).