Current colorectal cancer screening in developing countries: Identifying optimal approaches

Table 1 Summarized characteristics of colorectal cancer screening modalities

Modality	Sensitivity & specificity of advanced adenoma	Sensitivity & specificity of colorectal cancer	Participation rate (organized program)	Cost in United States dollars	Cost-effective analysis	Features
G-FOBT	Sensitivity: 0.19[30]	Sensitivity: 0.50-0.75 (95%CI: 0.09-1.0). Specificity: 0.96-0.98 (95%CI: 0.95-0.99)[28]	G-FOBT vs FIT: 46.9% vs 59.6%[35]	$4[92]	-	Qualitative tests. Samples from 3 days are needed. Diet restriction. Repeat applications are needed. It could be mailed
FIT	Sensitivity: 0.23 (95%CI: 0.20-0.25; I2 = 47.4%). Specificity: 0.96 (95%CI: 0.95-0.97; I2 = 94.8%) (at a threshold of 20 μg/g)[28]	Sensitivity: 0.74 (95%CI: 0.64-0.83; I2 = 31.6%). Specificity: 0.94 (95%CI: 0.93-0.96; I2 = 96.6%)[28]	From the first round to subsequent rounds: 48.2%, 75.3%, 83.4% and 86.1%[93]. FIT vs colonoscopy: 41.6% vs 21.9% (P < 0.01)[41]	$18[92]	ICER: Annual FIT: $14300/QALY, biennial FIT: $3970/QALY[45]	Repeat applications are needed. It could be mailed
mt-sDNA	Sensitivity: 0.43 (95%CI: 0.40-0.46). Specificity: 0.89 (95%CI: 0.86-0.92)[28]	Sensitivity: 0.93 (95%CI: 0.87-1.0). Specificity: 0.84 (95%CI: 0.84-0.86)[28]	71%[94]	$509[92]	ICER: $27500 per QALY[45]. Lower cost-effectiveness compared with no screening, but higher than colonoscopy, FS, CTC every 5 years, and annually FIT[44,45]	Repeat applications are needed
Colonoscopy	Sensitivity: 0.95 (95%CI: 0.77-1.00). Specificity: 0.89 (95%CI: 0.86-0.91) (compared with a reference standard of CTC for adenomas 10 mm or larger)[59]	-	21.9%[41]	$1891[92]	Lower cost-effectiveness compared with no screening[49,50]. ICER for single colonoscopy: $28071 per LYG[23]	Serious adverse events: 3.1 perforations (95%CI: 2.3-4.0) per 10000 procedures; 14.6 major bleeding events (95%CI: 9.4-19.9) per 10000 procedures[28]. Require bowel preparation
FS	-	-	63.1%[95]	$789[92]	Lower cost-effectiveness compared with no screening[44,50]. ICER for FS: Below $28,000 per QALY[44]	Serious adverse events: 0.7/10000 procedures[28]
CTC	Laxative-free CTC, ≥ 10 mm: Close to optical colonoscopy; ≥ 6 mm: Sensitivity: 0.59, specificity: 0.94[59]. CTC with bowel preparation, ≥ 6 mm: Sensitivity: 0.73-0.98; specificity: 0.80-0.93[28]	-	5.78%[59]	$477 (without contrast). $573 (with contrast)[92]	Lower cost-effectiveness compared with no screening. Higher cost-effectiveness compared with FIT, FS and colonoscopy[44]	Little to no risk of serious adverse events. low-dose ionizing radiation (0.8-5.3 mSv) exposure allergy[28]
mSeptin9	Epi proColon: Sensitivity: 0.64 (95%CI: 0.48-0.77)[64,65]	Epi proColon: Sensitivity: 0.68 (95%CI: 0.53-0.80). Specificity: 0.80 (95%CI: 0.78-0.82)[64,65]. Epi proColon 2.0: Sensitivity: 0.71-0.95. Specificity: 0.81-0.99[66]	-	$192[68]	-	-
Cell-free DNA blood-based test (Shield)	Sensitivity: 0.13. Specificity: 0.89[68]	Sensitivity: 0.83[68]	-	$949[23]	Higher cost-effectiveness than no screening. ICER: $377538 per LYG[23]	-

G-FOBT: Guaiac-based fecal occult blood test; FIT: Fecal immunochemical test; FS: Flexible sigmoidoscopy; CTC: Computed tomographic colonography; ICER: Incremental cost-effectiveness ratio; QALY: Qualified-adjusted-life-year; LYG: Life-year-gained.