In a multivariate analysis, post-PLC positivity, but not pre-PLC positivity, independently predicted poor RFS (hazard ratio, 3.06; p < 0.001).<h4>Conclusion</h4>Post-PLC, but not pre-PLC, provides decisive prognostic information for recurrence and pleural dissemination, likely reflecting residual lavage-resistant tumor clusters. Here, HSPG2 is linked to neoplasm.