REAL-WORLD TRANSITION PROBABILITY ANALYSES AMONG UNRESECTABLE LOCALLY ADVANCED (LA) ESOPHAGEAL/GASTROESOPHAGEAL JUNCTION CANCER (EC/GEJC) PATIENTS TREATED WITH DEFINITIVE CHEMORADIOTHERAPY (DCRT) AT COMMUNITY ONCOLOGY CENTERS
Author(s)
Liya Wang, PhD1, Helen Latimer, MPH2, Annabelle Davies, MSc1, Junxin Shi, PhD2, John Murphy, MS2, Gregory Patton, MD2, Sonal Bordia, MD1, Sujatha Nallapareddy, MD3.
1Merck & Co., Inc., Rahway, NJ, USA, 2Ontada, Boston, MA, USA, 3Rocky Mountain Cancer Centers, Aurora, CO, USA.
1Merck & Co., Inc., Rahway, NJ, USA, 2Ontada, Boston, MA, USA, 3Rocky Mountain Cancer Centers, Aurora, CO, USA.
OBJECTIVES: Patients with LA EC/GEJC ineligible for surgery are typically treated with dCRT, but recurrence is common, and mortality is high. This study assessed transition probabilities between different health states using real-world electronic health record data to evaluate recurrence rates and mortality.
METHODS: Patients with LA EC/GEJC who initiated dCRT within The US Oncology Network from January 2015 to June 2021 were included in the study. Follow-up was assessed until the last contact date by December 2022. Patients transitioned among pre-defined health states: event-free (EF), locoregional progression (LRP), and distant metastatic recurrence or progression (DM), until death. Six transition probability models (EF to LRP, EF to DM, EF to Death, LRP to DM, LRP to Death, and DM to Death) were assessed using Kaplan-Meier survival methods. Patients without events were censored at their last contact dates and those who experienced multiple events (LRP, DM, Death) were counted once in the latest stage model and otherwise censored for competing risks.
RESULTS: By definition, all 300 patients in this analysis started at EF. Median age at dCRT start date was 73 years, and a majority of patients were male (74.3%). Most patients were diagnosed at Stage III (55.7%), and most tumors were esophageal (70.7%). Starting from the EF state with a median follow-up time of 10.5 months, 41(14%) experienced LRP, 51 patients experienced DM (17%), and there were 107 (36%) death events. From LRP, there were 9 (22%) DM and 24 (59%) death events, respectively. From DM, there were 36 (71%) death events. Kaplan-Meier curves illustrated progressive declines in survival, with the highest mortality rate from DM to Death.
CONCLUSIONS: This real-world study demonstrated that the hazard of death increases as patients progress through health states, emphasizing the importance of delaying recurrence. These findings emphasize an unmet need for more early-stage therapies in LA EC/GEJC.
METHODS: Patients with LA EC/GEJC who initiated dCRT within The US Oncology Network from January 2015 to June 2021 were included in the study. Follow-up was assessed until the last contact date by December 2022. Patients transitioned among pre-defined health states: event-free (EF), locoregional progression (LRP), and distant metastatic recurrence or progression (DM), until death. Six transition probability models (EF to LRP, EF to DM, EF to Death, LRP to DM, LRP to Death, and DM to Death) were assessed using Kaplan-Meier survival methods. Patients without events were censored at their last contact dates and those who experienced multiple events (LRP, DM, Death) were counted once in the latest stage model and otherwise censored for competing risks.
RESULTS: By definition, all 300 patients in this analysis started at EF. Median age at dCRT start date was 73 years, and a majority of patients were male (74.3%). Most patients were diagnosed at Stage III (55.7%), and most tumors were esophageal (70.7%). Starting from the EF state with a median follow-up time of 10.5 months, 41(14%) experienced LRP, 51 patients experienced DM (17%), and there were 107 (36%) death events. From LRP, there were 9 (22%) DM and 24 (59%) death events, respectively. From DM, there were 36 (71%) death events. Kaplan-Meier curves illustrated progressive declines in survival, with the highest mortality rate from DM to Death.
CONCLUSIONS: This real-world study demonstrated that the hazard of death increases as patients progress through health states, emphasizing the importance of delaying recurrence. These findings emphasize an unmet need for more early-stage therapies in LA EC/GEJC.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
RWD6
Topic
Real World Data & Information Systems
Topic Subcategory
Health & Insurance Records Systems
Disease
SDC: Gastrointestinal Disorders, STA: Multiple/Other Specialized Treatments