Approach to early-onset colorectal cancer: Clinicopathological, familial, molecular and immunohistochemical characteristics

Table 2 Clinical, pathological, and familial characteristics of the global group and the microsatellite stable and microsatellite instability groups n (%)

	Global	MSS	MSI	P (χ2)
Patients	45 (100)	29 (69)1	13 (31)1
Median age of onset (range, yr)	39 (25-45)	41 (25-45)	37 (32-42)	0.032
Sex
Male	23 (51)	13 (45)	7 (54)
Female	22 (49)	16 (55)	6 (46)	NS
Location
Right colon	20 (45)	11 (38)	9 (69)
Left colon	15 (33)	11 (38)	2 (16)
Rectum	10 (22)	7 (24)	2 (15)	NS
Tumor differentiation
Well	2 (4)	2 (7)	0 (0)
Moderate	36 (80)	23 (79)	10 (77)
Poor	7 (16)	4 (14)	3 (23)	NS
Mucin production	15 (33)	5 (17)	5 (39)	NS
“Signet ring” cells	4 (9)	0/29 (0)	4/13 (30)	0.006
Modified Astler Coller stage
A	3 (7)	2 (7)	0 (0)
B	17 (38)	12 (41)	5 (39)
C	15 (33)	7 (24)	6 (46)
D	10 (22)	8 (28)	2 (15)	NS
Associated polyps during follow-up	15 (33)	10 (35)	4 (31)	NS
Synchronous or metachronous CRCs	3 (7)	1 (3)	1 (8)	NS
Familial history of cancer
Lynch-related neoplasms in family	18 (40)	5 (17)	11 (85)	< 0.01
Lynch unrelated neoplasms	12 (27)	8 (28)	7 (54)	0.02
Sporadic cases	27 (60)	24 (83)	2 (15)	< 0.001

¹Proportions were calculated for 42 tumors;

²Statistical comparison between microsatellite stable (MSS) and microsatellite instability (MSI) groups was performed using Student´s t test. CRC: Colorectal cancer; NS: Not significant.