Nasopharyngeal carcinoma another tobacco-related disease
19 Apr 2021
There is robust evidence suggesting that smoking increases the risk of nasopharyngeal carcinoma (NPC) in men, according to a team of researchers.
The researchers conducted an individual participant data (IPD) meta-analysis of six eligible population-based cohorts in NPC-endemic regions, including two each in Guangzhou and Taiwan, and one each in Hong Kong and Singapore. These cohorts contributed to a total of 334,935 male participants.
Over 2,961,315 person-years of follow-up, 399 men developed NPC. Cox proportional hazard models applying one- and two-stage approaches showed that smokers had more or less 30-percent higher risk of developing NPC compared with never smokers (hazard ratio [HR]one-stage, 1.32, 95 percent confidence interval [CI], 1.07–1.63; p=0.0088; HRtwo-stage, 1.27, 95 percent CI, 1.01–1.60; p=0.04).
The risk increase appeared to be pronounced among ever smokers who consumed 16+ cigarettes/day (HRone-stage, 1.67, 95 percent CI, 1.29–2.16; p=0.0001) and among those who started smoking at a young age (<16 years; HRone-stage, 2.16, 1.33–3.50; p=0.0103), with dose-response relationships (p=0.0028 and p=0.0103, respectively).
Conversely, quitting (versus daily smoking) conferred nominal protection against the risk (stopped for 5+ years: HRone-stage, 0.91, 95 percent CI, 0.60–1.39; p=0.66; for former smokers: HRtwo-stage, 0.84, 0.61–1.14; p=0.26).
In light of the findings, the researchers recommended that NPC be added to the 12–16 cancer sites known to be tobacco-related cancers. In addition, they called for strong tobacco control policies, preventing young individuals from smoking, to reduce NPC risk in endemic regions.