Impact of adjuvant chemotherapy on long-term overall survival in patients with high-risk stage II colon cancer: a nationwide cohort study

Figures & data

Figure 1. Flow chart.

Figure 2. a. Kaplan-Meier survival curve of 408 eligible high-risk UICC stage II colon cancer patients. b. Kaplan-Meier survival curve of 182 eligible high-risk UICC stage II colon cancer patients with pT4 tumors.

Table 1. The distribution of high-risk features in 939 patients with UICC stage II colon cancer alive 90 days after resection.

High-risk feature	Total		Individual subtotals without other high-risk features
	N	(%)	N	(% of total)
Emergency presentation	271	(28.9)	169	(62.4)
Bowel obstruction	193	(20.6)	121	(62.7)
Perforation	45	(4.8)	24	(53.3)
Other	33	(3.5)	24	(70.6)
Anastomotic leakage	157	(16.7)	120	(76.4)
Grade B	6	(0.6)	5	(83.3)
Grade C	151	(16.1)	115	(76.2)
Lymph node yield < 12	85	(9.1)	59	(69.4)
pT4	554	(59.0)	436	(78.7)
Signet cell carcinoma	18	(1.9)	16	(88.9)
Multiple			139	(.)

Numbers and percentages do not reach 939 as some high-risk features overlap.

Table 3. Type of adjuvant chemotherapy in 939 patients with high-risk UICC stage II colon cancer.

	Eligible for chemotherapy		Not eligible for chemotherapy
	N = 408	(43.5%)	N = 531	(56.5%)
No chemotherapy	207	(50.7)	438	(82.5)
Chemotherapy	201	(49.3)	93	(17.5)
FOLFOX	19	(9.5)	13	(14.0)
CAPOX	26	(12.9)	14	(15.0)
Capecitabine	111	(55.2)	54	(58.1)
Fluorouracil	23	(11.4)	3	(3.2)
Not specified	22	(10.9)	9	(9.7)

Eligible refers to patients <75 years of age with proficient mismatch repair gene expression and a performance status less than 3.

Table 2. Differences in 408 eligible patients with high-risk UICC stage II colon cancer according to administration of adjuvant chemotherapy.

	Adjuvant chemotherapy		No adjuvant chemotherapy		p
	N = 201	(49.3%)	N = 207	(50.7%)
Age, median (IQR)	66	(60–70)	68	(62–71)	0.004
Gender					0.039
Female	93	(46.3)	75	(36.2)
Male	108	(53.7)	132	(63.8)
Year of diagnosis					0.891
2014	52	(25.9)	54	(26.1)
2015	39	(19.4)	43	(20.8)
2016	40	(19.9)	45	(21.7)
2017	44	(21.9)	37	(17.9)
2018	26	(12.9)	28	(13.5)
WHO Performance status					<0.001
0	158	(78.4)	127	(61.4)
1	37	(18.4)	56	(27.1)
2	6	(3.0)	24	(11.6)
Charlson comorbidity index score					0.043
0	138	(68.7)	134	(64.7)
1–2	52	(25.9)	47	(22.7)
3+	11	(5.5)	26	(12.6)
Surgical procedure					0.316
Right colectomy	86	(42.8)	70	(33.8)
Left colectomy	27	(13.4)	38	(18.4)
Sigmoid colectomy	72	(35.8)	77	(37.2)
Colectomy	12	(6.0)	15	(7.2)
Other	4	2.0)	7	(3.4)
Surgical approach					0.130
Open	60	(29.9)	81	(39.1)
Laparoscopic	124	(61.7)	113	(54.6)
Robot assisted	17	(8.5)	13	(6.3)
High-risk features					<0.001
Emergency presentation	33	(16.4)	36	(17.4)
Anastomotic leakage	10	(5.0)	56	(27.1)
Lymph node yield < 12	5	(2.5)	21	(10.1)
pT4	124	(61.7)	58	(28.0)
Multiple	29	(14.4)	36	(17.4)

Eligible refers to patients <75 years of age with proficient mismatch repair gene expression and a performance status less than 3.

Data availability statement

Due to the nature of the research and due to ethical and legal restrictions, data is not available.