Letter to the editor: Serum S100A6 as complementary biomarker for pancreatic cancer-an advance needing clearer delineation

Table 1 Comparison of the original study’s “early-stage” cohort with an ideal screening population (asymptomatic stage I pancreatic cancer)

Characteristic	Original study “early” group (n = 149)	Ideal screening population (asymptomatic stage I)	Implication
TNM stage I	9 (6%)	100%	Results largely reflect stage II, not very early disease
TNM stage II	140 (94%)	0%	-
Symptom status	Mostly symptomatic (tertiary referral)	Asymptomatic	Unable to assess screening performance
Tumor size	Not reported, but stage II typically > 4 cm1	Usually ≤ 4 cm	Sensitivity for small tumors unknown

¹Based on general tumor, node, metastasis staging guidelines (stage II: T3–T4, tumor > 4 cm or extending beyond pancreas).

Data for the original study are from Bae et al[1]. The ideal screening population is defined as asymptomatic individuals with stage I pancreatic cancer detected through population-based screening programs; a scenario not represented in the original study. TNM: Tumor, node, metastasis.