Proportion of Time Covered (PTC) is A Better Measure of HCC Surveillance Quality: Gut | August 2026

Introduction:

Regular surveillance is essential for the early detection of hepatocellular carcinoma (HCC) in high-risk patients, increasing the likelihood of curative treatment. However, real-world adherence to surveillance remains suboptimal, and current methods for measuring adherence are inconsistent and often fail to reflect the actual time patients remain protected by surveillance. This study evaluated Proportion of Time Covered (PTC) as a standardized, time-based measure of HCC surveillance adherence and examined its relationship with clinical outcomes.

Why was this study needed?

HCC surveillance adherence is generally poor in routine clinical practice.

Existing adherence metrics are heterogeneous and may overestimate surveillance quality.

A standardized method is needed to accurately assess surveillance performance across healthcare systems.

Better adherence measurement could identify gaps in surveillance pathways and improve early cancer detection.

The relationship between surveillance adherence and curative treatment has not been well established.

Results:

The study included 1,409 patients undergoing HCC surveillance over a four-year period.

Using the PTC method, adherence was relatively low for alpha-fetoprotein (AFP) testing and surveillance ultrasound alone but substantially higher when all clinically relevant abdominal imaging was considered.

Nearly half of HCC cases were diagnosed at an early stage (BCLC 0–A), allowing potentially curative treatment in more than half of affected patients.

Higher PTC for abdominal imaging was significantly associated with greater likelihood of receiving curative treatment, emphasizing the importance of maintaining continuous surveillance coverage rather than simply counting completed tests.

The aMAP risk score successfully stratified patients according to future HCC risk, supporting its role in individualized surveillance strategies.

The findings demonstrate that PTC provides a more accurate reflection of real-world surveillance quality than traditional annual testing rates.

Clinical Impact:

This study proposes Proportion of Time Covered (PTC) as a standardized quality indicator for HCC surveillance. Unlike conventional measures, PTC captures how consistently patients remain protected throughout the surveillance period and better reflects real-world clinical practice. Incorporating all abdominal imaging performed during routine care provides a more realistic assessment of surveillance adherence and identifies patients more likely to receive curative therapy through earlier cancer detection. PTC could become an important quality benchmark for liver clinics and future HCC surveillance programs.

Bottom Line:

Proportion of Time Covered (PTC) is a more precise measure of HCC surveillance adherence than conventional methods and is associated with higher rates of curative treatment. Adoption of PTC as a standardized surveillance quality metric may improve benchmarking, optimize surveillance pathways, and enhance early detection of hepatocellular carcinoma.