SCC-Ag and CEA Monitoring Shows Limited Diagnostic Value for Esophageal Squamous Cell Carcinoma Recurrence Post-dCRT
Background
For patients with esophageal squamous cell carcinoma (ESCC), definitive chemoradiotherapy (dCRT) is a common treatment. Post-treatment surveillance is crucial for early detection of recurrence, but the optimal strategy remains debated. In Japan, Squamous Cell Carcinoma Antigen (SCC-Ag) and Carcinoembryonic Antigen (CEA) are routinely monitored, yet their actual clinical utility and incremental diagnostic value beyond imaging and endoscopy have been unclear. This study aimed to clarify the significance of these tumor markers in a cohort undergoing intensive surveillance, addressing a gap in evidence for their routine use.
Study Design
Researchers analyzed pooled data from 239 patients with resectable ESCC who received dCRT in the JCOG0502 and JCOG0909 trials. These patients underwent intensive, protocolized surveillance including computed tomography (CT), esophagogastroduodenoscopy (EGD), and routine monitoring of SCC-Ag and CEA. Tumor marker positivity was defined as exceeding a cut-off value at least once, at two consecutive measurements, or at three consecutive measurements during follow-up. Sensitivity and specificity were calculated for SCC-Ag and CEA at 0.1-ng/mL increments to determine if any cut-off met predefined performance criteria (sensitivity ≥60% and specificity ≥70%).
Results
Among the 239 patients included (stage I/II/III = 147/58/34), 38% (91/239) experienced disease progression or recurrence. The median baseline SCC-Ag and CEA levels were 1.0 ng/mL (IQR, 0.8-1.5) and 2.3 ng/mL (IQR, 1.6-3.6), respectively, with a median of 16 measurements each during follow-up. Despite extensive monitoring, neither marker met the predefined performance criteria for diagnostic value. The highest specificities achieved with sensitivity ≥60% were notably low:
For SCC-Ag, the highest specificity was 19.6% at a cut-off of 1.5 ng/mL. For CEA, the highest specificity was 20.3% at a cut-off of 2.2 ng/mL. These findings indicate that while the markers are routinely measured, their ability to accurately identify recurrence while minimizing false positives is limited, even in a cohort with intensive
CTandEGDsurveillance.
Key Findings
- 38% (91/239) of patients experienced ESCC recurrence post-dCRT.
- SCC-Ag achieved a maximum specificity of 19.6% (at 1.5 ng/mL cut-off) with sensitivity ≥60%.
- CEA achieved a maximum specificity of 20.3% (at 2.2 ng/mL cut-off) with sensitivity ≥60%.
- Neither SCC-Ag nor CEA met the predefined performance criteria (sensitivity ≥60%, specificity ≥70%) for recurrence detection.
Why It Matters
This study provides crucial evidence suggesting that routine SCC-Ag and CEA monitoring offers limited incremental diagnostic value for ESCC recurrence after dCRT, particularly when patients are already undergoing intensive CT and EGD surveillance. For clinicians, this implies that resources spent on routine tumor marker tests might be better reallocated, or that the interpretation of these markers should be significantly downplayed in the context of comprehensive imaging and endoscopic follow-up. The findings challenge current Japanese clinical practice and highlight the need for more effective, specific biomarkers or refined surveillance strategies. While not directly impacting peptide protocols, this research informs the broader landscape of cancer surveillance, emphasizing that not all 'routine' tests are clinically impactful.
esophageal-squamous-cell-carcinoma
escc
biomarker
scc-ag
cea
cancer-surveillance