Splenomegaly (SPML) in PV patients (pts) is sometimes considered a diagnostic hallmark, often associated with symptoms. SPML affected clinical trial design and influenced governmental approval of ropeginterferon α-2b. Whether SPML affects myelofibrosis-free and overall survival (MFS and OS) is unknown. We retrospectively studied these issues by querying spleen size, and correlating them with demographics, symptoms, marrow fibrosis, ELN/NCCN risk score, and MFS and OS.
Of 403 phlebotomy-dependent pts, we distinguished 176 pts (44%) diagnosed (DX) at onset of disease, from 227 (56%) presenting initially (PRES) after diagnosis elsewhere. At DX, 73% (128/176) had no SPML, indicating it is an uncommon marker. SPML pts at DX were younger. Only 11/374 pts had left upper quadrant discomfort. Constitutional symptoms at DX or PRES were frequent, regardless of spleen size, which did not correlate with ELN/NCCN risk scores. Marrow biopsy revealed fibrosis most often in pts at PRES with spleen enlargement, suggesting early onset myelofibrosis, but OS was the same.
We show that PV pts uncommonly have SPML at DX, rarely symptomatic, but often constitutionally symptomatic. Pts may require marrow biopsy, especially if spleen edge ≥5cm, to establish fibrosis/degree, which, if present, particularly in younger pts may require disease-modifying therapy.