Microsatellite instability is biased in Amsterdam II-defined Lynch-related cancer cases with family history but is rare in other cancers: a summary of 1000 analyses

Table 4 Factors associated with MSI-H in colorectal cancers (n = 466)

	n	MSI positive		Univariate analysis		Multivariate analysis
	n	n	%	Odd’s ratio (95% confidence interval)	P value	Odd’s ratio (95% confidence interval)	P value
Patient
Age
≤ 50y.o.	86	19	22.1%	2.11 (1.17–3.82)	0.02
> 50y.o	380	45	11.8%
Gender
Male	283	36	12.7%	0.81 (0.48–1.37)	0.49
Female	183	28	15.3%
Personal and/or family history
AII criteria
(+)	40	17	42.5%	5.96 (3.00–11.87)	< 0.0001
(−)	426	47	11.0%
rB guidelines
(+)	259	51	19.7%	3.66 (1.93–6.94)	< 0.0001
(−)	207	13	6.3%
≥ 3 LS(rB)-related cancers# in FDR, SDR and TDR
(+)	51	17	33.3%	3.91 (2.03–7.55)	0.0001
(−)	415	47	11.3%
≥ 3 any cancers in FDR, SDR and TDR
(+)	120	27	22.5%	2.43 (1.41–4.18)	0.002
(−)	346	37	10.7%
Colorectal cancer patient in FDR
(+)	132	30	22.7%	2.60 (1.52–4.44)	0.001	9.98 (1.47–205.1)	0.046
(−)	334	34	10.2%
Colorectal cancer
Location
Right-side colon	155	42	27.1%	4.88 (2.80–8.51)	< 0.0001	5.21(2.61–10.81)	< 0.0001
Left-side colon	311	22	7.1%
Stage
Early	39	12	30.8%	3.21 (1.55–6.65)	0.003
Advanced	427	52	12.2%
Multiplicity (simultaneous + metachronous)
(+)	49	15	30.6%	3.31 (1.70–6.47)	0.001
(−)	417	49	11.8%
Purpose of MSI test
Genetic counseling	127	53	41.7%	21.36 (10.74–42.40)	< 0.0001	24.98 (10.07–70.08)	< 0.0001
Companion diagnostics	339	11	3.2%

MSI-H high frequency of microsatellite instability, AII Amsterdam II, rB revised Bethesda, LS Lynch syndrome

ISSN: 1471-2407