Table 4 Univariable and multivariable Cox regression models of factors affecting overall survival.

Age

764

1.03

1.02–1.04

<0.001

0.99

0.98–1.00

0.009

Primary tumour location

Right colon

291

1

1

Left colon

206

0.78

0.64–0.95

0.012

1.08

0.87–1.34

0.475

Rectum

262

0.65

0.54–0.78

<0.001

1.00

0.81–1.22

0.972

Unknown

5

2.18

0.81–5.87

0.123

1.87

0.69–5.09

0.222

Tumour grade

Low

466

1

1

High

216

1.87

1.57–2.22

<0.001

1.57

1.30–1.90

<0.001

Not available

82

2.52

1.97–3.22

<0.001

1.56

1.19–2.04

0.001

Presentation of metastases

Synchronous

509

1

1

Metachronous

255

0.81

0.68–0.95

0.012

1.20

1.00–1.44

0.050

Number of metastatic sites

1

366

1

1

2

273

1.65

1.36–1.93

<0.001

1.28

1.07–1.54

0.008

3–5

125

2.09

1.68–2.60

<0.001

1.51

1.20–1.90

<0.001

ECOG PS^a

0

252

1

1

1

243

2.57

2.09–3.17

<0.001

1.95

1.56–2.43

<0.001

2–4

269

6.65

5.38–8.21

<0.001

2.85

2.23–3.65

<0.001

Type of treatment^a

Systemic therapy only

334

1

1

Metastasectomy

213

0.18

0.14–0.23

<0.001

0.23

0.18–0.30

<0.001

Best supportive care

217

2.60

2.18–3.11

<0.001

2.56

2.01–3.27

<0.001

Mutation groups

BRAF-V600Emt

123

1

1

RASmt

365

0.46

0.37–0.57

<0.001

0.48

0.38–0.62

<0.001

RAS&BRAFwt

220

0.40

0.31–0.52

<0.001

0.43

0.33–0.56

<0.001

Not tested

56

1.48

1.07–2.05

0.018

0.67

0.44–1.00

0.051

MMR status

pMMR

585

1

1

dMMR

58

1.43

1.07–1.92

0.016

0.51

0.36–0.70

<0.001

Not tested

121

2.02

1.64–2.50

<0.001

1.14

0.88–1.48

0.307