Facility-level JSMO specialist availability and reconstructable treatment-process measures in colorectal cancer using...

Area of Science:

• Oncology
• Health Services Research

Background:

• The Cancer Registry of Japan (C-CAT) database lacks patient-level data on Japanese Society of Medical Oncology (JSMO) specialist involvement.
• Assessing JSMO specialist availability and its impact on colorectal cancer treatment processes within C-CAT is crucial.

Purpose of the Study:

• To evaluate the association between facility-level JSMO specialist availability and colorectal cancer treatment process measures reconstructable by C-CAT.
• To determine if JSMO specialist presence influences treatment timelines and endpoint ascertainment in colorectal cancer care.

Main Methods:

• A nationwide retrospective analysis of 11,906 colorectal cancer patients across 261 facilities using C-CAT data.
• Primary exposure: facility-level JSMO specialist count (0-3 vs. 4+). Secondary exposure: gastrointestinal-domain JSMO specialist presence.
• Primary endpoint: time from systemic therapy start to second-line treatment end, analyzed using facility-cluster robust Cox models.

Main Results:

• No significant difference in time to second-line treatment end was observed after adjustment (HR 0.968; p=0.565).
• Overall survival also showed no advantage associated with higher specialist numbers (HR 0.962; p=0.648).
• Second-line end-date availability was lower in facilities with 4+ specialists (61.6% vs. 69.1%).

Conclusions:

• Current C-CAT data can reconstruct facility-level treatment measures but do not support attributing clinical outcomes to JSMO specialist involvement.
• Direct evaluation of specialist impact necessitates chemotherapy-specific national database elements for robust interpretation.