Purpose
This study evaluates the prognostic significance of tumor size at disease progression (PD) and depth of response (DOR) in cancer patients.
Materials and Methods
We performed post hoc analysis using data from six prospective clinical trials conducted by the Korean Cancer Study Group. Patients with tumor size at PD was categorized into ‘Mild PD’ and ‘Significant PD’ based on the cutoff values of relative change from baseline using maximally selected rank statistics. The overall survival (OS) and progression-free survival (PFS) were compared between PD and DOR categories.
Results
Among the 194 evaluable patients, 130 experienced PD. A 35.48% decrease from baseline in tumor size at PD was chosen for the cutoff between mild and significant PD for OS (mild PD: tumor size from the baseline ≤ −35.48%; significant PD > −35.48%). The mild PD had superior OS compared to the significant PD (25.8 vs. 12.8 months; Hazard ratio [HR] 0.47, 95% CI 0.266-0.843, p=0.009). When using an exploratory cutoff based on whether the tumor size was below vs. exceeded from the baseline (mild PD: tumor size from the baseline ≤ 0%; significant PD > 0%), OS remained significantly longer in the mild PD (17.1 vs. 11.8 months; HR 0.60, 95% CI 0.392-0.932, p=0.021). The greatest DOR was associated with the longest OS and PFS (p<0.001 for both).
Conclusion
Tumor size at PD and DOR were significant prognostic factors for progressive disease. Maintaining a sufficiently reduced tumor size even during PD was associated with better survival outcomes.
Citations
Citations to this article as recorded by
Baseline tumor burden and outcomes in patients with rare cancers treated with immunotherapy (Southwest Oncology Group trial S1609) Paul L. Swiecicki, Megan Othus, Sandip P. Patel, Young Kwang‐Chae, Razelle Kurzrock Cancer.2026;[Epub] CrossRef
Pathology features of recurrent meningioma V.V. Ushanov, Yu.M. Zabrodskaya, A.Yu. Ulitin, D.A. Sitovskaya, A.S. Sharova, A.A. Paltsev, A.V. Vasilenko, K.K. Kukanov Russian Journal of Archive of Pathology.2025; 87(5): 28. CrossRef