RAND/UCLA Modified Delphi Panel on the Severity, Testing, and Medical Management of PIK3CA-Related Spectrum Disorders (PROS)

mutation and medical therapy in 217 patient scenarios before a virtual meeting. Panelists discussed areas of disagreement and completed ratings following the meeting. Results: The panel developed clinical presentations and endorsed the disease severity framework defined by functional impairment, a reduction in quality of life, and risk of death. Panelists agreed it is appropriate to test for a PIK3CA gene variant in every mod-erately/severely affected patient. Panelists agreed it may be appropriate to consider an mammalian (mechanistic) target of rapamycin inhibitor in some severely affected patients and some moderately affected patients with progressive disease. Although clinical trials have only recently begun and the evidence remains limited, panelists also agreed it may be appropriate to consider treatment with phosphoinositide 3-kinase/serine/threonine protein kinase inhibitors in severely affected patients with a confirmed PIK3CA variant or without a confirmed variant but with progressive disease. Conclusion: These recommendations represent the consensus of experts informed by published literature and experience. Future research should validate this guidance using clinical data. Once validated, we hope these recommendations will improve outcomes for patients with PROS.