Administration of adjuvant oxaliplatin to patients with stage III colon cancer is affected by age and hospital

Figures & data

Table I. Characteristics of patients with resected stage III colon cancer, by adjuvant treatment (n = 1140).

	OX (n = 533) n (%)	nOX (n = 145) n (%)	NoCT (n = 462) n (%)	p-value*
Gender Male Female	302 (57) 231 (43)	77 (53) 68 (47)	228 (49) 234 (51)	0.070
Age < 70 70–74 ≥ 75	413 (77) 84 (16) 36 (7)	49 (34) 29 (20) 67 (46)	69 (15) 62 (13) 331 (72)	< 0.0001
SES Low Intermediate High Institutions Unknown	83 (16) 226 (43) 194 (36) 13 (2) 17 (3)	33 (23) 59 (40) 39 (27) 4 (3) 10 (7)	142 (31) 151 (32) 119 (26) 27 (6) 23 (5)	< 0.0001
Comorbidity 0 1 ≥ 2 Unknown	231 (43) 144 (27) 150 (28) 8 (2)	43 (30) 40 (27) 61 (42) 1 (1)	84 (18) 98 (21) 269 (58) 11 (3)	< 0.0001
T stage 1 2 3 4 Unknown	7 (1) 56 (11) 395 (74) 41 (8) 34 (6)	9 (6) 14 (10) 104 (72) 12 (8) 6 (4)	7 (2) 37 (8) 332 (72) 42 (9) 44 (9)	0.013
N stage 1 2	345 (65) 188 (35)	100 (69) 45 (31)	333 (72) 129 (28)	0.045
Subsite Proximal colon Distal colon Other/NOS	266 (50) 258 (48) 9 (2)	89 (61) 55 (38) 1 (1)	277 (60) 177 (38) 8 (2)	0.002
Differentiation grade Well/moderate Poor/undifferentiated Unknown	399 (75) 105 (20) 29 (5)	105 (72) 32 (22) 8 (6)	301 (65) 125 (27) 36 (8)	0.010
Period of diagnosis 2008–2009 2010–2011	263 (49) 270 (51)	88 (61) 57 (39)	207 (45) 255 (55)	0.004

NoCT, no chemotherapy; nOX, non-oxaliplatin-based chemotherapy; OX, oxaliplatin-based chemotherapy. *p-value indicates significance of the χ²-test.

Figure 1. Observed and expected proportions of patients receiving oxaliplatin-based chemotherapy (dotted dark grey) and non- oxaliplatin-based chemotherapy (shaded light grey) among patients with resected stage III colon cancer, by hospital of treatment and age group; expected proportions based on casemix adjustment for gender, age, SES, comorbidity, T stage, N stage, subsite, differentiation grade and period of diagnosis (A: n = 531; B: n = 175; C: n = 434).

Table II. Crude percentages and odds ratios^a for receipt of oxaliplatin-based adjuvant chemotherapy among patients with stage III colon cancer treated with adjuvant chemotherapy (n = 678).

	Crude %	Odds ratio (95% CI)
Gender Male Female	80 77	1.00 (reference) 1.08 (0.69–1.72)
Age < 70 70–74 ≥ 75	89 74 35	1.00 (reference) 0.37 (0.21–0.64) 0.06 (0.03–0.11)
SES Low Intermediate High Institutions Unknown	72 79 83 76 63	1.00 (reference) 1.24 (0.68–2.29) 1.47 (0.76–2.83) 0.43 (0.11–1.62) 0.82 (0.27–2.45)
Comorbidity 0 1 ≥ 2 Unknown	84 78 71 89	1.00 (reference) 0.91 (0.51–1.61) 0.86 (0.49–1.49) 0.95 (0.11–8.48)
T stage 1 2 3 4 Unknown	44 80 79 77 85	0.15 (0.04–0.50) 1.08 (0.50–2.36) 1.00 (reference) 1.79 (0.74–4.33) 1.68 (0.54–5.16)
N stage 1 2	78 81	1.00 (reference) 1.18 (0.72–1.93)
Subsite Proximal colon Distal colon Other/NOS	75 82 90	1.00 (reference) 1.40 (0.87–2.26) 2.07 (0.22–19.06)
Differentiation grade Well/moderate Poor/undifferentiated Unknown	79 77 78	1.00 (reference) 0.90 (0.51–1.60) 1.14 (0.42–3.09)
Period of diagnosis 2008–2009 2010–2011	75 83	1.00 (reference) 2.08 (1.26–3.44)
Hospital of treatment A B C D E F G H I J	84 90 92 82 75 81 67 74 64 69	0.59 (0.20–1.75) 1.82 (0.50–6.59) 1.95 (0.70–5.47) 1.00 (reference) 0.54 (0.22–1.31) 0.93 (0.37–2.33) 0.35 (0.14–0.85) 0.53 (0.22–1.26) 0.26 (0.10–0.69) 0.39 (0.15–1.04)

^aAdjusted for all variables listed.