TableS1. Clinicopathological characteristics of elderly patients (>70 years) according to 5-FU-based adjuvant chemotherapy

Adjuvant chemotherapy
Total
(n=213) / Yes
(n=73) / No
(n=140) / p-value
Number / Number / % / Number / %
Sex
Male / 117 / 47 / 40.2 / 70 / 59.8 / 0.045
Female / 96 / 26 / 27.1 / 70 / 72.9
Age
Median (range) / 74(71–92) / 73(71–85) / 76(71–92) / <0.001
Histologic differentiation
Well -differentiated / 24 / 11 / 45.8 / 13 / 54.2 / 0.459
Moderately- differentiated / 175 / 57 / 32.4 / 119 / 67.6
Poorly- differentiated / 8 / 4 / 50.0 / 4 / 50.0
Mucinous / 3 / 1 / 33.3 / 2 / 66.7
Others / 2 / 0 / 0 / 2 / 100
T stage
T3 / 193 / 61 / 31.6 / 132 / 68.4 / 0.011
T4 / 20 / 12 / 60.0 / 8 / 40.0
Number of lymph nodes harvested
Median and range / 21(4–65) / 19(2–50) / 20(2–65) / 0.673
Lymphovascular invasion or perineural invasion
Yes / 26 / 14 / 53.8 / 12 / 46.2 / 0.025
No / 187 / 59 / 31.6 / 128 / 68.4
Tumor location
Proximal / 99 / 31 / 31.3 / 68 / 68.7 / 0.396
Distal / 144 / 42 / 36.8 / 72 / 63.2
Bowel obstruction or tumor perforation
Yes / 17 / 8 / 47.1 / 9 / 52.9 / 0.247
No / 196 / 65 / 33.2 / 131 / 66.8
Serum CEA (ng/mL)
Median and range / 2.97(0–624.49) / 2.86(0–624.49) / 3.10(0–69.57) / 0.765
Microsatellite instability
MSI-high / 27 / 9 / 33.3 / 18 / 66.7 / 0.148
MSI-low / 8 / 2 / 25.0 / 6 / 75.0
MSS / 160 / 60 / 37.5 / 100 / 62.5
Unknown / 18 / 2 / 11.1 / 16 / 88.9
Treatment era
1998-2005 / 41 / 19 / 46.3 / 22 / 53.7 / 0.070
2006-2009 / 172 / 54 / 31.4 / 118 / 68.6

N/A, not assessed

TableS2. Correlation between several risk factors and cancer specific survival using simple linear and multiple Cox analyses in all patients (n=716)

Simple linear regression / Multipleregression
Variables / N / HR / 95% CI / p-value / HR / 95% CI / p-value
Adjuvant chemotherapy
Yes / 489 / 0.456 / 0.244-0.853 / 0.014 / 0.411 / 0.215-0.786 / 0.007
No / 227 / 1 / 1
T stage
T4 / 60 / 3.308 / 1.578-6.934 / 0.002 / 2.962 / 1.385-6.334 / 0.005
T3 / 656 / 1 / 1
Age
>70 years / 213 / 2.324 / 1.241-4.353 / 0.008
≤70 years / 503 / 1
Histologic differentiation
Poorly-differentiated / 22 / 1.868 / 0.451-7.740 / 0.389
Others / 694 / 1
Number of lymph node harvested
<12 / 106 / 1.393 / 0.641-3.017 / 0.400
≥12 / 610 / 1
Lymphovascular invasion or perineural invasion
Yes / 82 / 0.680 / 0.210-2.207 / 0.521
No / 634 / 1
Bowel obstruction or perforation
Yes / 35 / 4.301 / 1.904-9.718 / <0.001 / 3.464 / 1.500-7.998 / 0.004
No / 681 / 1 / 1
Tumor location
Distal / 413 / 1.312 / 0.688-2.503 / 0.410
Proximal / 303 / 1
Serum CEA
>5 ng/mL / 164 / 3.463 / 1.868-6.417 / <0.001 / 3.545 / 1.898-6.650 / <0.001
≤5 ng/mL / 552 / 1 / 1
Microsatellite instability
MSI-low or MSS / 515 / 1
MSI-high / 99 / 1.035 / 0.394-2.723 / 0.944
Treatment era
2006-2009 / 511 / 0.752 / 0.394-1.435 / 0.387
1999-2005 / 205 / 1

CEA, carcinoembryonic antigen; CI, confidence interval; HR, hazard ratio; MSI, microsatellite instability; MSS, microsatellite stable

TableS3. Clinicopathological characteristics of the patients with T4 disease according to 5-FU-based adjuvant chemotherapy

Adjuvant chemotherapy
Total
(n=60) / Yes
(n=50) / No
(n=10) / p-value*
Number / Number / % / Number / %
Sex
Male / 39 / 34 / 87.2 / 5 / 12.8 / 0.298
Female / 21 / 16 / 76.2 / 5 / 23.8
Age
>70 years / 17 / 9 / 52.9 / 8 / 47.1 / <0.001
≤70 years / 43 / 41 / 95.3 / 2 / 4.7
Histologic differentiation
Well -differentiated / 5 / 4 / 80.0 / 1 / 20.0 / 0.685
Moderately- differentiated / 47 / 39 / 83.0 / 8 / 17.0
Poorly- differentiated / 3 / 2 / 66.7 / 1 / 33.3
Mucinous / 4 / 4 / 100 / 0
Others / 1 / 1 / 100 / 0
Tumor location
Proximal / 27 / 24 / 88.9 / 3 / 11.1 / 0.488
Distal / 33 / 26 / 78.8 / 7 / 21.2
Hypertension
Yes / 16 / 12 / 75.0 / 4 / 25.0 / 0.433
No / 44 / 38 / 86.4 / 6 / 13.6
Diabetes mellitus
Yes / 13 / 10 / 76.9 / 3 / 23.1 / 0.675
No / 47 / 40 / 85.1 / 7 / 14.9
Underlying chronic disease (other than hypertension or diabetes mellitus) †
Yes / 6 / 5 / 83.3 / 1 / 16.7 / >0.99
No / 54 / 45 / 83.3 / 9 / 16.7
Limitation in basic ADLs‡
Yes / 1 / 1 / 100 / 0 / >0.99
No / 59 / 49 / 83.1 / 10 / 16.9
Treatment era
1998-2005 / 14 / 9 / 64.3 / 5 / 35.7 / 0.044
2006-2009 / 46 / 41 / 89.1 / 5 / 10.9

ADLs, activities of daily living

*P-values were calculated using Fisher’s exact test.

†These chronic diseases included old cerebrovascular accidents, chronic kidney disease, arrhythmia, and chronic obstructive pulmonary disease.

‡ADLs were evaluated with several factors including bathing, dressing, toileting, transfer, continence, and feeding (Katz et al., JAMA 1963).

Supplement Figure Legends

Fig S1. RFS according to adjuvant chemotherapy for all patients; (B) CSS according to adjuvant chemotherapy in all patients.

Fig S2.RFS according to adjuvant chemotherapy for patients with T4 disease; (B) CSS according to adjuvant chemotherapy in patients with T4 disease.

1