Finding an oral potentially malignant disorder in screening program is related to early diagnosis of oral cavity cancer - Experience from real world evidence.

OBJECTIVES

Our study evaluates the effectiveness of the Taiwan Oral Mucosal Screening (TOMS) program in stage-shift among oral cavity cancer patients, and identifies the related factors with early cancer diagnosis.

MATERIALS AND METHODS

This retrospective cohort study used the Taiwan Cancer Registry (TCR), TOMS and Taiwan Death Registry (TDR) databases. We identified oral cavity cancer patients (ICD-C-O: C00-C06) from the TCR during 2012-2015. Patients' screening history, first screening status and subsequent screenings were analyzed with cancer stages and survival outcomes.

RESULTS

The 5-year survival rates for stages 0-4 were 83.9%, 82.1%, 72.7%, 60.1% and 38.0%. Among 18,625 patients identified from the TCR, 37% did not have any prior screenings. Patients with prior positive or negative screenings all had better survival rates (3-year: 71.4% and 68.7% vs. 63.5%, Log-rank p-value < 0.0001). The best chance for early-stage diagnosis occurs in oral potentially malignant disorder (OPMD, OR = 1.99, 95% CI = 1.78-2.22, p < 0.0001) patients at their first screenings. The hazard ratios (HR) for patients with prior screenings indicated a significant survival benefit. The group of incomplete diagnosis confirmation also has better survival (HR = 0.78, 95% CI = 0.81-0.93, p < 0.0001), and a greater chance of early diagnosis at subsequent screenings.

CONCLUSION

While TOMS improved stage-shift for early cancer diagnosis, we found no obvious differences in participants with cancers at screening (stages 0-1: 26.3% vs. 27.8% in non-screening group). Survival benefit and early diagnosis are found in most of screening groups, and identifying an OPMD is particularly essential to early diagnosis of oral cavity cancer patients.