Epidemiology

Smoking and HCV infection increase the risk of non-Hodgkin lymphoma

Last Updated: 2005-07-01 15:41:42 -0400 (Reuters Health)

By Megan Rauscher

NEW YORK (Reuters Health) - Results of an Italian case-control study confirm that heavy smoking doubles the risk of developing non-Hodgkin lymphoma (NHL). The study also shows that hepatitis C virus (HCV)-positive individuals who are heavy smokers have an approximately 4-fold elevated risk of NHL.

"Smoking is a well-documented risk factor for several cancers, but the role of cigarette smoking in the etiology of NHL is inadequately understood," lead researcher Dr. Renato Talamini from the National Cancer Institute in Aviano told Reuters Health. HCV has been associated with NHL, he noted, but the interplay between tobacco use and HCV has not been studied.

Dr. Talamini and his colleagues studied relationships between HCV, smoking habits and NHL in 225 consecutive patients hospitalized with a new diagnosis of NHL and 504 matched control patients hospitalized for a wide range of acute, non-neoplastic, non-immune, non-tobacco-related conditions.

Compared with never smokers, current smokers of 20 or more cigarettes per day had an odds ratio for NHL of 2.10, the investigators report in the July 1st issue of the International Journal of Cancer. This finding was consistent for both sexes and all age groups.

The odds ratio for NHL was 2.64 for HCV seropositivity.

"The effects of tobacco smoking and HCV infection seemed to act independently on NHL risk, leading to a grossly elevated risk for heavy smokers who are HCV positive," Dr. Talamini told Reuters Health. "Tobacco and HCV seem to act at different stages of the process of NHL carcinogenesis."

Summing up, the researcher noted that about 5% to 10% of NHL cases could be prevented by persuading people to quit smoking and by integrated policies and health programmes aimed at reducing HCV infection.

"Health professionals could play a key role in reducing NHL incidence in the population," Dr. Talamini contends, by promoting healthy lifestyles and behaviours, engaging in anti-smoking campaigns, providing support for people who are quitting, and, in the absence of proven HCV vaccine, promoting interventions against risky behaviours including intravenous drug use and unprotected sexual intercourse.

Int J Cancer 2005;115:606-610.