Outcomes of adding induction chemotherapy to concurrent chemoradiotherapy for stage T3N0-1 nasopharyngeal carcinoma: a propensity-matched study

Figures & data

Table 1 Characteristics of stage T3N0-1 NPC treatment with IC + CC or CC before and after propensity score matching

Characteristics	Before propensity score matching					After propensity score matching
	IC + CC (n=260)		CC (n=427)		P-valuea	IC + CC (n=237)		CC (n=237)		P-valuea
	n	%	n	%		n	%	N	%
Gender					0.859					0.424
Male	181	69.6	300	70.3		161	67.9	169	71.3
Female	79	30.4	127	29.7		76	32.1	68	28.7
Age (years)					0.031					0.756
≤50	195	75.0	287	67.2		172	72.6	175	73.8
>50	65	25.0	140	32.8		65	27.4	62	26.2
Pathology typeb					0.884					0.724
Type I + II	8	3.1	14	3.3		5	2.1	3	1.3
Type III	252	96.9	413	96.7		232	97.9	234	98.7
Smoking					0.448					0.433
Yes	81	31.2	145	34.0		73	30.8	81	34.2
No	179	68.8	282	66.0		164	69.2	156	65.8
NPC family history					0.847					0.442
Yes	28	10.8	44	10.3		26	11	21	8.9
No	232	89.2	383	89.7		211	89	216	91.1
Pre-EBV DNA (copies/m	L)				<0.001					0.456
<4,000	144	55.4	311	72.8		142	59.9	134	56.5
≥4,000	116	44.6	116	27.2		95	40.1	103	43.5
N category					<0.001					0.111
N0	27	10.4	90	21.1		27	11.4	39	16.5
N1	233	89.6	337	78.9		210	88.6	198	83.5

Notes:

a P-values were calculated by using χ² test or Fisher exact test if indicated.

b Based on WHO histological type: I – differentiated keratinizing carcinoma, II – differentiated nonkeratinizing carcinoma, and III – undifferentiated non-keratinizing carcinoma.

Abbreviations: CC, concurrent chemotherapy; EBV DNA, Epstein–Barr virus deoxyribonucleic acid; IC, induction chemotherapy; NPC, nasopharyngeal carcinoma; WHO, World Health Organization.

Table 2 Patterns of treatment failure in 237 patient pairs with stage T3N0-1 NPC

Failure pattern	IC plus CC	CC	P-valuea	Total
Local/regional recurrence alone			0.081
Local	4	5		9
Regional	6	1		7
Local and regional	5	1		6
Total	15	7		22
Distant metastases alone			0.565
Bone	5	5		10
Lung	4	5		9
Liver	3	3		6
Brain	1	0		1
Multiorgan	3	0		3
Total	16	13		29
Distant metastases and recurrence	2	1		3
Total	33	21	0.083	54

Note:

a P-values were calculated by using χ² test or Fisher exact test if indicated.

Abbreviations: CC, concurrent chemotherapy; IC, induction chemotherapy; NPC, nasopharyngeal carcinoma.

Figure 1 Kaplan–Meier survival curves for IC plus CC and CC alone in 237 patient pairs.

Notes: (A) Overall survival; (B) locoregional relapse-free survival; (C) distant metastasis-free survival; (D) progression-free survival.
Abbreviations: CC, concurrent chemotherapy; IC, induction chemotherapy.

Table 3 Summary of prognostic factors in 237 patient pairs with stage T3N0-1 NPC by univariate analysis

Factors	n	4-year OS (%)	P-valuea	4-year LRFS (%)	P-valuea	4-year DMFS (%)	P-valuea	4-year PFS (%)	P-valuea
Gender			0.871		0.393		0.419		0.178
Male	300	91.7		95.7		94.6		91.4
Female	144	93		92.3		92.1		84.6
Age (years)			0.861		0.620		0.828		0.603
≤50	347	92.4		94.9		93.7		89.5
>50	127	91		94.1		94.3		88.5
Pathological type			0.37		0.465		0.416		0.286
Type I + II	8	100		100		100		100
Type III	466	91.9		94.6		93.8		89
Smoking			0.705		0.831		0.551		0.694
Yes	154	93.1		95.2		94.2		90.8
No	320	91.6		94.4		93.7		88.5
NPC family history			0.346		0.091		0.236		0.913
Yes	47	85.2		100		91.4		91.4
No	427	92.7		94.1		94.2		89
Pre-EBV DNA			0.887		0.358		0.044		0.118
<4,000	276	93.3		95.8		95.5		91.3
≥4,000	198	90.5		93.1		91.6		86.4
Chemotherapy			0.794		0.138		0.582		0.223
IC plus CC	237	91.7		92.7		93.5		87.5
CC	237	92.6		96.8		94.3		91.1
N category			0.732		0.598		0.373		0.226
N0	66	92.9		95.2		95.5		92.2
N1	408	92		94.6		93.6		88.7

Note:

a P-values were calculated by using the unadjusted log-rank test.

Abbreviations: CC, concurrent chemotherapy; DMFS, distant metastasis-free survival; EBV DNA, Epstein–Barr virus deoxyribonucleic acid; IC, induction chemotherapy; LRFS, locoregional relapse-free survival; NPC, nasopharyngeal carcinoma; OS, overall survival; PFS, progression-free survival.

Table 4 Summary of prognostic factors in 237 patient pairs with stage T3N0-1 NPC by multivariate analysis

Factors	OS			LRFS			DMFS			PFS
	HR	95% CI	P-valuea	HR	95% CI	P-valuea	HR	95% CI	P-valuea	HR	95% CI	P-valuea
Gender	0.86	0.39–1.89	0.713	1.79	0.69–4.70	0.234	1.73	0.73–4.12	0.215	1.82	0.94–3.53	0.076
Age (years)	1.10	0.53–2.29	0.808	1.26	0.54–2.96	0.595	0.90	0.39–2.02	0.793	1.16	0.64–2.11	0.618
Pathological type	–	–	0.979	–	–	0.989	–	–	0.972	–	–	0.962
Smoking	0.81	0.37–1.79	0.608	1.40	0.53–3.76	0.499	1.59	0.67–3.81	0.295	1.45	0.73–2.85	0.286
NPC family history	1.57	0.60–4.06	0.357	–	–	0.976	1.88	0.72–4.92	0.202	0.94	0.37–2.38	0.901
Pre-EBV DNA	1.05	0.38–0.83	0.897	1.35	0.61–2.99	0.459	2.08	1.00–4.32	0.05	1.48	0.85–2.57	0.164
Chemotherapy	0.90	0.53–2.08	0.760	1.91	0.85–4.33	0.119	1.23	0.61–2.48	0.569	1.40	0.81–2.42	0.229
N category	1.17	0.45–3.10	0.745	1.05	0.30–3.64	0.945	1.29	0.38–4.38	0.683	1.40	0.54–3.60	0.485

Note:

a P-values were calculated by using an adjusted Cox proportional hazard model with the forward conditional method.

Abbreviations: DMFS, distant metastasis-free survival; EBV DNA, Epstein–Barr virus deoxyribonucleic acid; HR, hazard ratio; LRFS, locoregional relapse-free survival; NPC, nasopharyngeal carcinoma; OS, overall survival; PFS, progression-free survival.

Table 5 Grade 3–4 hematological toxicities in 237 patient pairs with stage T3N0-1 NPC

Hematological toxicity	IC plus CC	CC	P-value
Leucopenia	82 (34.6%)	38 (16.0%)	<0.001
Neutropenia	97 (40.9%)	14 (5.9%)	<0.001
Anemia	10 (4.2%)	4 (1.7%)	0.104
Thrombocytopenia	27 (11.4%)	22 (9.3%)	0.451

Note: P-values were calculated by using χ² test or Fisher exact test if indicated.

Abbreviations: CC, concurrent chemotherapy; IC, induction chemotherapy; NPC, nasopharyngeal carcinoma.