Purpose: Comprehensive genomic profiling (CGP) of sarcomas is rapidly being integrated into routine clinical care to help refine diagnosis and prognosis and determine treatment. However, little is known about barriers to successful CGP or its clinical utility in sarcoma. We set out to determine whether CGP alters physician treatment decision-making, and whether sarcoma subtypes influence the frequency of successful technical performance of CGP.
Methods: A single-institution study evaluated profiling outcomes of 392 samples from patients with sarcoma, using a commercially available CGP panel. Of this group, 34 patients were evaluated prospectively (Decision Impact Trial) to evaluate the utility of CGP in physician decision-making. All cases were retrospectively analyzed to identify causes of CGP failure.
Results: CGP successfully interrogated 75.3% (n = 295 of 392) of patients with sarcoma. Bone sarcomas had lower passing rates at 65.3% (n = 32 of 49) compared with soft tissue sarcomas at 76.7% (n = 263 of 343; P = .0008). Biopsy location also correlated with profiling efficiency. Bone biopsy specimens had a 52.8% (n = 19 of 36) passing rate versus lung (61.1%; n = 33 of 54) and abdomen (80.1%; n = 109 of 136) specimens. CGP altered physician treatment selection in 25% of evaluable patients (n = 7 of 28) and was associated with improved progression-free survival.
Conclusion: To our knowledge, this is the largest technical evaluation of the performance of CGP in sarcoma. CGP was effectively performed in the vast majority of sarcoma samples and altered physician treatment selection. Tumor location and tissue subtype were key determinants of profiling success and associated with preanalytic variables that affect DNA and RNA quality. These results support standardized biopsy collection protocols to improve profiling outcomes.
© 2020 by American Society of Clinical Oncology.