Prognostic Value of KRAS Gene Mutation on Survival of Patients with Peritoneal Metastases of Colorectal Adenocarcinoma

Table 1

Patient and tumour characteristics and survival estimate rates (95% CI) at 36 months after diagnosis.

	Patients (%) (total = 149)	Cumulative survival 36 months (%)	Median	value	HR	95% CI
Sex
Men	85 (57%)	24	22	0.72	1
Women	64 (43%)	24	20		1.07	0.73–1.56
Age (years)
<50	17 (11.4%)	41	27	0.14	1
50–69	80 (53.7%)	26	23		1.76	0.88–3.52
>70	52 (34.9%)	16	16		1.29	0.66–2.54
Location
Right colon	64 (43%)	15	17	0.21	1
Left colon	64 (43%)	32	25		0.86	0.49–1.51
Rectum	21 (14%)	19	24		0.69	0.46–1.05
ECOG Index
0	34 (22.8%)	47	36	<0.001	1	1.47–4.19
1-2	115 (77.2%)	17	17		2.49
T stage
T3	68 (45.6%)	26	24	0.42	1
T4	81 (54.6%)	23	19		1.16	0.79–1.7
N stage
N0	27 (18%)	51	NR	<0.001	1	1.55–5.19
N1-2	122 (81%)	18	21		2.84
Time of diagnostics
Synchronic	77 (51.7%)	14	18	0.03	1
Metachronic	72 (48.3%)	26	26		0.65	0.44–0.96
Site of metastases
Peritoneum only	61 (40.9%)	33	25	0.01	1
Peritoneum + liver	51 (34.2%)	27	21		2.08	1.26–3.41
Peritoneum + lung	8 (5.4%)	12	15		2	0.89–4.5
Multiple	29 (19.5%)	6	13		1.27	0.8–2.01
Grade of differentiation
Well to moderate	111 (74.5%)	30	25	<0.001	1
Poor	38 (25.5%)	6	12		2.36	1.56–3.57
Histologic type
Classical adenocarcinoma	105 (70.5%)	31	27	<0.001	1
Mucinous	44 (29.5%)	9	12		2.54	1.7–3.8
KRAS status
WT-KRAS	74 (49.7%)	35	28	<0.001	1	1.48–3.2
MT-KRAS	75 (50.3%)	14	15		2.18
Peritoneal cancer index
1–10	46 (30.9%)	56	NR	<0.001	1
11–20 (a)	63 (42.3%)	10	22		7.43	4.16–13.24
>20 (b)	40 (28.8%)	0	13		2.59	1.53–4.36
Chemotherapy treatment
5-FU-based programs plus bevacizumab/cetuximab	103 (69.1%)	52	NR	<0.001	1
5-FU-based programs	46 (30.9%)	9	14		2.86	1.92–4.24
Primary tumour resection
Yes	130 (87.2%)	27	22	<0.001	1
No	19 (12.8%)	0	15		2.29	1.34–3.90
HIPEC
Yes	36 (75.8%)	64	60	<0.001	1
No	113 (24.2%)	11	15		5.45	2.98–10.04

The log-rank test was used to calculate values. HR: hazard ratio; 95% CI: 95% confidence interval; NR: not reached. Hazard ratio compares PCI: (a) PCI 11–20 versus PCI 1–10; (b) PCI >20 versus PCI 11–20.