Evaluating the benefit of adjuvant chemotherapy in patients with ypT0–1 rectal cancer treated with preoperative chemoradiotherapy

Table 1 Clinicopathological characteristics of the study patients

Variables		ACTx (n = 413)	No ACTx (n = 107)	P value
Age, mean ± SD, yr		58 ± 10.1	63.4 ± 11.0	< 0.001
Sex, n (%)				0.659
	Male	243 (58.8)	66 (61.7)
	Female	170 (41.2)	41 (38.3)
cT category, n (%)				< 0.001
	cT1–2	83 (20.1)	48 (44.9)
	cT3–4	330 (79.9)	59 (55.1)
cN category, n (%)				< 0.001
	cN-	65 (15.7)	34 (31.8)
	cN+	348 (84.3)	73 (68.2)
Type of surgery, n (%)				< 0.001
	Radical resection	378 (91.5)	64 (59.8)
	Local excision	35 (8.5)	43 (40.2)
Number of examined LNs, mean ± SD1		14.7 ± 6.9	14.6 ± 6.3	0.892
pT category, n (%)				0.099
	ypT0	294 (71.2)	67 (62.6)
	ypTis–1	119 (28.8)	40 (37.4)
pN category1, n (%)				0.201
	ypN0	347 (91.8)	62 (96.9)
	ypN+	31 (8.2)	2 (3.1)
Lymphovascular invasion, n (%)		4 (1)	-	0.339
Follow-up duration mean ± SD, months		72.1 ± 33.0	66.4 ± 30.3	0.105

¹Only for radical resection.

SD: Standard deviation; ACTx: Adjuvant chemotherapy; LN: Lymph node.

Table 2 Sites of initial recurrence according to the status of adjuvant chemotherapy

Variables		ACTx (n = 413)	No ACTx (n = 107)	P value
Recurrence, n (%)		43 (10.4)	8 (7.4)
Type of recurrence, n (%)				0.009
	Local recurrence	3 (0.7)	4 (3.7)
	Distant metastasis	40 (9.7)	4 (3.7)
Sites of distant metastasis1, n (%)
	Liver	8 (20)	1 (12.5)
	Lung	23 (57.5)	2 (25)
	Distant lymph nodes	6 (15)	1 (12.5)
	Bone	4 (10)	-
	Brain	1 (2.5)	-
	Ovary	1 (2.5)	-

¹Among patients with distant metastasis.

ACTx: Adjuvant chemotherapy.

Table 3 Risk factors associated with recurrence-free survival

		Univariate		Multivariate
		HR	P value	HR	95%CI	P value
Adjuvant chemotherapy			0.459			0.608
	No	1		1
	Yes	1.331		1.226	0.563–2.671
Sex			0.582
	Male	1
	Female	1.77			0
cT category			0.082			0.035
	cT1–2	1		1
	cT3–4	2.031		2.565	1.06–6.156
cN category			0.399
	cN−	1
	cN+	0.756
Type of surgery			0.927
	Local excision	1
	Radical resection	1.038
ypT stage			0.389
	ypT0	1
	ypTis–1	0.757

HR: Hazard ratio; CI: Confidence interval.

Table 4 Risk factors associated with overall survival

		Univariate		Multivariate
		HR	P value	HR	95% CI	P value
Adjuvant chemotherapy			0.306			0.484
	No	1		1
	Yes	0.729		0.797	0.422–1.504
Age		1.047	0.001	1.052	1.022–1.084	0.001
Sex			0.156			0.213
	Male	1		1
	Female	0.668		0.701	0.400–1.227
cT category			0.122			0.029
	cT1–2	1		1
	cT3–4	1.757		2.268	1.085–4.741
cN category			0.475
	cN−	1
	cN+	1.296
Type of surgery			0.692
	Local excision	1
	Radical resection	1.174
ypT stage			0.612
	ypT0	1
	ypTis–1	0.861

HR: Hazard ratio; CI: Confidence interval.