Plasma Epstein-Barr virus DNA and risk of nasopharyngeal carcinoma in a prospective seropositive population

BMC Cancer

Table 3 Predictive value of EBV DNA for NPC development by different follow-up duration

Variables	> 2 years		> 3 years		> 4 years
	Adjusted HR(95%CIs)	*P-value*	Adjusted HR(95%CIs)	*P-value*	Adjusted HR(95%CIs)	*P-value*
≤3(undetectable)	Reference		Reference		Reference
> 3 (detectable)	10.878 (4.215–28.072)	< 0.0001^a	5.139 (1.136–23.252)	0.0336^a	4.054 (0.500–32.845)	0.1898^a
> 3–999	9.637 (3.491–26.607)	< 0.0001^b	2.785 (0.359–21.619)	0.3273^b	4.472 (0.552–36.257)	0.3739^b
≥1000	30.111 (3.662–247.587)		33.560 (3.996–281.872)		–

^aHRs are adjusted by sex, age, smoking status, NPC family history, salted food,education level; ^b P trend for the comparision among EBV DNA undetectable group, DNA levels at > 3–999 copies/ml and DNA levels ≥1000 copies/ml

ISSN: 1471-2407