Influences of Patient Characteristics on the Predictive Value of Molecular Biomarkers of Colon Cancer in Tubular Adenomas

Article Figures & Data

Download figure
Open in new tab
Download powerpoint
Figure 1.
Median of LINE-1 methylation levels of each independent risk group (no secondary average = 64.8%, secondary index = 75.8%, secondary lesion = 68.9%). LINE-1 methylation levels were significantly lower in index polyps without (left) vs index lesion with (center) secondary lesions (P < .001). Paired-sample analysis of secondary index and secondary lesion samples displayed significant LINE-1 hypomethylation in the secondary lesion samples (z = −2.009, P = .045).
Download figure
Open in new tab
Download powerpoint
Figure 2.
Total number of participants in each group (with or without secondary lesions) by age (<60 years, and 60 years and older). The group with secondary lesions contained a statistically older patient population (Chi-Square P = .019).
Download figure
Open in new tab
Download powerpoint
Figure 3.
(A) Regression analysis of age vs LINE-1 methylation. (B) Methylation of LINE-1 with dichotomized age (Mann-Whitney U Test, P = 0.085). Under 60 median methylation = 55%, 60 and over median methylation = 62%.
Download figure
Open in new tab
Download powerpoint
Figure 4.
(A) Smaller polyps were found more frequently in the 60 and over group (Chi-Square P = 0.008). (B) Median LINE-1 promoter methylation compared to polyp size (P = 0.014). Under 5 mm: median methylation = 72%, 6 mm and over: median methylation = 67%.

Table 1.

Demographics vs absence (No) and presence (Yes) of secondary lesions

Descriptor	Total	No	Yes
Descriptor	n = 65	n = 35	n = 30
Sex
Male	37	21	16
Female	28	14	14
Race
African American	28	14	14
Caucasian	27	13	14
Other	10	8	2
Smoking history
Yes	42	12	11
No	23	23	19
Age^a (range)
<60 years (44–59)	25	18	7
≥60 years (60–85)	40	17	23
Polyp location
Distal	24	15	9
Proximal	38	18	20
Mixed	3	2	1
Polyp size^b
<5 mm	32	11	22
6–9 mm	24	18	6
Mixed	9	6	2

↵a There was a significantly older patient population in the group with secondary lesions (P = .019).
↵b There were significantly more smaller polyps in the group with secondary lesions (P = .002).

Table 2.

Mutations detected by TST15 tumor panel sequencing

NGS True Sight 15 Tumor (TST 15) Panel	Index Polyps		Secondary Lesions
NGS True Sight 15 Tumor (TST 15) Panel	Without Secondary Lesions^a	With Secondary Lesions^b	Secondary Lesions
No mutations found	7	9	8
Mutations found	3	5	6
Total (% with mutations)	10 (30%)	14 (36%)	14 (43%)

↵a Mutations in polyps without secondary lesions: BRAF (n = 1) and TP53 (n = 2).
↵b Mutations in polyps with secondary lesions: BRAF (n = 1), KRAS (n = 1), and TP53 (n = 3).

Table 3.

Demographics and percent LINE-1 methylation

Descriptor	Number of Cases n = 65	LINE-1 CpG Site 1	LINE-1 CpG Site 2	LINE-1 CpG Site 3	LINE-1 Average
Age (range)
<60 years (44–59)	25	92.8	55.4	55.9	67.6
≥60 years (60–85)	40	93.5	59.1	60.6	71.1
		P = .707	P = .149	P = .016	P = .105
Gender
Female	37	93.8	57.9	57.9	69.8
Male	28	92.5	58.0	59.5	70.0
		P = .489	P = .943	P = .422	P = .923
Race
African American	28	94.6	59.8	59.7	71.4
Caucasian	27	92.8	57.8	59.5	70.0
Other^a	10	89.2	51.0	54.4	64.9
		P = .330	P = .322	P = .931	P = .451
Smoking history
Yes	23	92.2	57.4	58.5	69.4
No	42	93.8	58.2	58.7	70.2
		P = .563	P = .745	P = .963	P = .726
Polyp location
Distal	24	91.4	56.5	57.6	68.5
Proximal	38	94.8	59.1	59.4	71.1
Mixed^b	3	86.0	53.3	56.7	65.3
		P = .064	P = .157	P = .400	P = .121
Polyp size
≤5 mm	32	94.3	59.6	60.3	71.4
6–9 mm	24	91.3	55.0	55.7	67.3
Mixed^b	9	91.3	55.8	58.4	68.5
		P = .127	P = .013	P = .020	P = .014
Metachronous tumors
No	35	89.2	52.6	52.7	64.8
Yes	30	97.9	64.1	65.5	75.8
		P < .001	P < .001	P < .001	P < .001

↵a Other included 3 Asian, 6 Hispanic, and 1 unknown.
↵b Cases in which multiple polyps were found that included both categories of size or location were excluded.