Cross-Source Progression Assessment in Advanced Pancreatic Cancer: An Opportunity-Adjusted Six-State Analysis

PURPOSE: Radiology and treating-oncologist documentation are recorded on different schedules in routine oncology care. We characterized the opposite clinical source at its first evaluable opportunity after radiology- or medical-oncology-documented progression in advanced pancreatic cancer using an exhaustive six-state framework. METHODS: We performed a retrospective secondary analysis of AACR Project GENIE BPC PANC v1.0-public. Patients entered the treatment-index cohort at the first systemic regimen initiated on or after advanced-disease onset. Process T0 was the first genuine radiology- or medical-oncology-documented progression after cohort entry and not after subsequent same-cancer treatment or death. The opposite source's first evaluable opportunity was classified as same-day concordance, confirmation, explicit nonprogression, mixed, indeterminate, or no evaluable opportunity. The secondary estimand was explicit nonprogression among first opportunities classifiable specifically as progression or explicit nonprogression. RESULTS: Of 1,109 patients, 882 entered the treatment-index cohort and 645 qualified for the primary estimand. States were same-day concordance in 25 (3.88%), confirmation in 219 (33.95%), explicit nonprogression in 108 (16.74%), mixed in 19 (2.95%), indeterminate in 166 (25.74%), and no evaluable opportunity in 108 (16.74%). Among 327 progression/nonprogression-classifiable first opportunities, 108 (33.03%; 95% CI, 28.15%-38.30%) documented explicit nonprogression. Opposite-source opportunity occurred after 88.47% of imaging-first events at a median of 5 days versus 62.94% of medical-oncology-first events at a median of 38 days. A known-regimen-completion sensitivity yielded 84/144 (58.33%). CONCLUSION: Cross-source progression assessment frequently did not yield immediate confirmation and often remained indeterminate or unevaluable. An opportunity-adjusted six-state framework makes observation-process and clinical-boundary dependencies explicit rather than compressing them into a binary discordance estimate.