Reduced risk of CIN2+ recurrence in women immunized with a 9-valent HPV vaccine post-excision: Retrospective cohort study

Figures & data

Figure 1. Flowchart of cohort study.

HPV – human papillomavirus.

Table 1. Baseline clinical a demographic characteristic for eligible and matched cohorts by 9vHPV vaccination status.

		Before matching			Matched cohorts
Characteristics		Unvaccinated (N = 366)	Vaccinated (N = 49)	Standardized difference	Unvaccinated (N = 98)	Vaccinated (N = 49)	Standardized difference
Age (years)		35.7 (9.0)	33.0 (6.3)	0.35	33.1 (6.4)	33.0 (6.3)	0.02
	<20	2 (0.5)	0 (0.0)	0.44
	20–30	101 (27.6)	17 (34.7)		34 (34.7)	17 (34.7)	0.00
	30–40	158 (43.2)	25 (51.0)		50 (51.0)	25 (51.0)
	40–50	88 (24.0)	7 (14.3)		14 (14.3)	7 (14.3)
	50–60	11 (3.0)	0 (0.0)
	>60	6 (1.6)	0 (0.0)
Folllow-up (months)		44.2 (33.2)	30.3 (20.8)	0.50	30.5 (23.2)	30.3 (20.8)	0.01
	<12	63 (17.2)	8 (16.3)	0.86	16 (16.3)	8 (16.3)	0.00
	12–24	62 (16.9)	16 (32.7)		32 (32.7)	16 (32.7)
	24–36	43 (11.7)	11 (22.4)		22 (22.4)	11 (22.4)
	36–48	52 (14.2)	6 (12.2)		12 (12.2)	6 (12.2)
	48–60	49 (13.4)	1 (2.0)		2 (2.0)	1 (2.0)
	>60	97 (26.5)	7 (14.3)		14 (14.3)	7 (14.3)
Comorbidity	No	299 (81.7)	42 (85.7)	0.11	79 (80.6)	42 (85.7)	0.14
	yYs	67 (18.3)	7 (14.3)		19 (19.4)	7 (14.3)
Smoker	No	69 (18.9)	17 (34.7)	0.36	13 (13.3)	17 (34.7)	0.52
	Yes	54 (14.8)	6 (12.2)		19 (19.4)	6 (12.2)
	Missing	243 (66.4)	26 (53.1)		66 (67.3)	26 (53.1)
Nulliparity	Yes	90 (24.6)	27 (55.1)	0.66	30 (30.6)	27 (55.1)	0.51
	No	276 (75.4)	22 (44.9)		68 (69.4)	22 (44.9)
CIN at LEEP	CIN2	169 (46.2)	19 (38.8)	0.15	45 (45.9)	19 (38.8)	0.14
	CIN3+	197 (53.8)	30 (61.2)		53 (54.1)	30 (61.2)
Cone margin	Negative	284 (77.6)	44 (89.8)	0.33	72 (73.5)	44 (89.8)	0.43
	Positive	82 (22.4)	5 (10.2)		26 (26.5)	5 (10.2)
HPV genotypes	HPV16/18+	178 (48.6)	11 (22.4)	0.57	38 (38.8)	11 (22.4)	0.39
	Other 12 HR ones	121 (33.1)	25 (51.0)		34 (34.7)	25 (51.0)
	Undetected	67 (18.3)	13 (26.5)		26 (26.5)	13 (26.5)

Data are presented in n (%) or mean (standard deviation).

Standardized differences quantify the difference between groups divided by the pooled standard deviation; a value > 10% (>0.10) is a meaningful difference between vaccinated and unvaccinated women.

CIN – cervical intraepithelial neoplasia.

CIN2/CIN3+ – cervical intraepithelial neoplasia of grade 2/grade 3 or worse.

LEEP – loop electrosurgical excision procedure.

HR – high risk.

HPV – human papillomavirus.

Figure 2. Probability of CIN2+ recurrence in 9vHPV-vaccinated and unvaccinated women relative to time since conization.

9vHPV – 9-valent vaccine against human papillomavirus infection.

Table 2. Poisson regression model to assess the relevant risk factors for CIN2 recurrence.

Risk factors		N° of women	N° of recurrence	IR/100,000 person-days	aIRR (95% CI)	p-value
9vHPV vaccination	No	98	16	18	ref
	Yes	49	1	2	0.10 (0.01–0.88)	0.038
Comorbidity	No	121	14	13	ref
	Yes	26	3	13	0.93 (0.25–3.48)	0.916
Smoker	No	30	1	3	ref
	Yes	25	4	16	2.90 (0.28–29.82)	0.371
	Missing	92	12	15	2.61 (0.30–22.48)	0.383
Nulliparity	Yes	57	6	12	ref
	No	90	11	13	0.36 (0.10–1.27)	0.114
CIN at LEEP	CIN2	64	4	7	ref
	CIN3+	83	13	16	3.34 (0.60–12.95)	0.081
Cone margin	Negative	116	9	8	ref
	Positive	31	8	28	3.31 (1.21–9.05)	0.020
HPV genotypes	HPV16/18+	49	7	15	ref
	Other 12 HR ones	59	9	16	1.10 (0.39–3.08)	0.862
	Undetected	39	1	3	0.17 (0.02–1.62)	0.125

IR – incidence rate.

aIRR – adjusted incidence rate ratio.

HPV16/18+ – at least one of both HPV genotypes with or without any other HR HPV genotypes.

Other 12 HR – at least one of the other non-HPV16 or HPV18 genotypes: 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and/or 68.

CIN – cervical intraepithelial neoplasia.

CIN2/CIN3+ – cervical intraepithelial neoplasia of grade 2/grade 3 or worse.

LEEP – loop electrosurgical excision procedure.

HPV – human papillomavirus.

HR – high risk.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.