Evaluation of clinical relevance of examining K-ras, p16 and p53 mutations along with allelic losses at 9p and 18q in EUS-guided fine needle aspiration samples of patients with chronic pancreatitis and pancreatic cancer

Table 1 Tests for K-ras, p53 and p16 mutations, and LOH at chromosome 9p (site of p16 gene) and LOH at chromosome 18q (site of DPC4 gene) n (%)

		Chronicpanceratitis	Pancreaticcancer	Total	Sensitivity(95% CI)	Specificity(95% CI)	P	Youden'sindex
K-ras	Negative	20 (100)	24 (29.6)	44 (43.6)	70%	100%	< 0.001	70%
	Positive	0 (0)	57 (70.4)	57 (56.4)	(60%-80%)
	Total	20 (100)	81 (100)	101 (100)
p53	Negative	18 (90)	62 (76.5)	80 (79.2)	24%	90%	0.18 (NS)	14%
	Positive	2 (10)	19 (23.5)	21 (20.8)	(14%-34%)	(85%-95%)
	Total	20 (100)	81 (100)	101 (100)
p16	Negative	20 (100)	70 (87.5)	90 (90)	13%	100%	0.096 (NS)	13%
	Positive	0 (0)	10 (12.5)	10 (10)	(7%-19%)
	Total	20 (100)	80 (100)	100 (100)
LOH 9p	Negative	9 (64.3)	8 (15.4)	17 (25.8)	85%	64%	< 0.001	49%
	Positive	5 (35.7)	44 (84.6)	49 (74.2)	(75%-95%)	(53%-75%)
	Total	14 (100)	52 (100)	66 (100)
LOH 18q	Negative	8 (57.1)	11 (22.4)	19 (30.2)	78%	57%	< 0.05	35%
	Positive	6 (42.9)	38 (77.6)	44 (69.8)	(67%-89%)	(45%-69%)
	Total	14 (100)	49 (100)	63 (100)

Table 2 Combination of test for various molecular markers

Combination of tests			95% CI	P	Youden'sindex
K-ras + LOH 9p	Sensitivity	92%	85%-99%	< 0.001	57%
	Specificity	64%	53%-75%
K-ras + LOH 18q	Sensitivity	92%	85%-99%	< 0.001	49%
	Specificity	57%	45%-69%
LOH 9p + LOH 18q	Sensitivity	92%	85%-99%	< 0.01	34%
	Specificity	43%	31%-55%
p16 + LOH 9p	Sensitivity	84%	74%-94%	< 0.001	49%
	Specificity	64%	53%-75%
K-ras + p53	Sensitivity	74%	65%-83%	< 0.001	64%
	Specificity	90%	85%-95%
K-ras + LOH 9p	Sensitivity	96%	92%-100%	< 0.001	39%
+ LOH 18q	Specificity	43%	31%-55%
K-ras + p16	Sensitivity	92%	85%-99%	< 0.001	57%
+ LOH 9p	Specificity	64%	53%-75%
p53 + LOH 9p	Sensitivity	92%	85%-99%	< 0.001	35%
+ LOH 18q	Specificity	43%	31%-55%