Lung Cancer Risk in HIV May Be Lower Than Thought

Major Finding: HIV infection is associated with an 80% increase in the risk of incident lung cancer after controlling for smoking and other known risk factors.

Data Source: Data on 3,707 HIV-positive individuals and 5,980 HIV-negative controls.

Disclosures: The researchers said they had no disclosures.

The increased risk for lung cancer associated with HIV infection appears to be more modest than previous studies had indicated.

The finding is based on a study of nearly 14,000 veterans who were followed for a median of 8 years. After controlling for smoking status, age, chronic obstructive pulmonary disease, and race and ethnicity, HIV infection was associated with a 1.8-fold increase in the risk of lung cancer, Dr. Keith Sigel said at the Conference on Retroviruses and Opportunistic Infections.

Previous studies had suggested that HIV infection was associated with a 2.5-fold to 3.6-fold increase in the risk of lung cancer.

Dr. Sigel of the Mount Sinai School of Medicine, New York, and his colleagues used data from the Veterans Aging Cohort Study (VACS), a “virtual” cohort of 33,420 HIV-positive individuals and 66,840 HIV-negative controls matched by age, race, gender, and site.

The VACS data set does not include information on smoking status. In order to control for smoking status, the investigators combined the VACS data set with data from the 1999 Large Health Survey of Veteran Enrollees. The merged dataset included 3,707 HIV-infected individuals and 9,980 healthy controls.

The median age of individuals in the cohort was 48 years, and 98% were male. Minorities were well represented: 41% were white, 39% were black, 10% were Hispanic, and 10% were of other races or ethnicities.

There were some significant baseline differences between HIV-infected and uninfected individuals in the cohort. HIV-infected individuals were more likely to be current daily smokers (32% vs. 28%), were more likely to be drug abusers (16% vs. 10%), and were more likely to have lung cancer at the beginning of the study (16 vs. 38 individuals). Individuals with prevalent lung cancer were excluded from the study.

The unadjusted absolute incidence of lung cancer was 26 cases/10,000 person-years among individuals who were HIV positive and 15 cases/10,000 person-years among individuals who were HIV negative.

Although the observed 80% increase in the risk of lung cancer associated with HIV infection was statistically significant, several other independent predictors conferred much larger risks of lung cancer. Current daily smoking was associated with a 9.8-fold increase in risk, and current occasional smoking was associated with a 3.4-fold increase in risk. Also, Hispanic ethnicity was associated with a 60% decrease in the risk of incident lung cancer.

“Our results represent a more modest risk than previous adjusted analyses, which may reflect differences in methods in our case identification, the presence of matched HIV controls for comparison within our cohort, or potentially greater precision allowed by our sample size,” Dr. Sigel said.

Major Finding: HIV infection is associated with an 80% increase in the risk of incident lung cancer after controlling for smoking and other known risk factors.

Data Source: Data on 3,707 HIV-positive individuals and 5,980 HIV-negative controls.

Disclosures: The researchers said they had no disclosures.

The increased risk for lung cancer associated with HIV infection appears to be more modest than previous studies had indicated.

The finding is based on a study of nearly 14,000 veterans who were followed for a median of 8 years. After controlling for smoking status, age, chronic obstructive pulmonary disease, and race and ethnicity, HIV infection was associated with a 1.8-fold increase in the risk of lung cancer, Dr. Keith Sigel said at the Conference on Retroviruses and Opportunistic Infections.

Previous studies had suggested that HIV infection was associated with a 2.5-fold to 3.6-fold increase in the risk of lung cancer.

Dr. Sigel of the Mount Sinai School of Medicine, New York, and his colleagues used data from the Veterans Aging Cohort Study (VACS), a “virtual” cohort of 33,420 HIV-positive individuals and 66,840 HIV-negative controls matched by age, race, gender, and site.

The VACS data set does not include information on smoking status. In order to control for smoking status, the investigators combined the VACS data set with data from the 1999 Large Health Survey of Veteran Enrollees. The merged dataset included 3,707 HIV-infected individuals and 9,980 healthy controls.

The median age of individuals in the cohort was 48 years, and 98% were male. Minorities were well represented: 41% were white, 39% were black, 10% were Hispanic, and 10% were of other races or ethnicities.

There were some significant baseline differences between HIV-infected and uninfected individuals in the cohort. HIV-infected individuals were more likely to be current daily smokers (32% vs. 28%), were more likely to be drug abusers (16% vs. 10%), and were more likely to have lung cancer at the beginning of the study (16 vs. 38 individuals). Individuals with prevalent lung cancer were excluded from the study.

The unadjusted absolute incidence of lung cancer was 26 cases/10,000 person-years among individuals who were HIV positive and 15 cases/10,000 person-years among individuals who were HIV negative.

Although the observed 80% increase in the risk of lung cancer associated with HIV infection was statistically significant, several other independent predictors conferred much larger risks of lung cancer. Current daily smoking was associated with a 9.8-fold increase in risk, and current occasional smoking was associated with a 3.4-fold increase in risk. Also, Hispanic ethnicity was associated with a 60% decrease in the risk of incident lung cancer.

“Our results represent a more modest risk than previous adjusted analyses, which may reflect differences in methods in our case identification, the presence of matched HIV controls for comparison within our cohort, or potentially greater precision allowed by our sample size,” Dr. Sigel said.

Major Finding: HIV infection is associated with an 80% increase in the risk of incident lung cancer after controlling for smoking and other known risk factors.

Data Source: Data on 3,707 HIV-positive individuals and 5,980 HIV-negative controls.

Disclosures: The researchers said they had no disclosures.

The increased risk for lung cancer associated with HIV infection appears to be more modest than previous studies had indicated.

The finding is based on a study of nearly 14,000 veterans who were followed for a median of 8 years. After controlling for smoking status, age, chronic obstructive pulmonary disease, and race and ethnicity, HIV infection was associated with a 1.8-fold increase in the risk of lung cancer, Dr. Keith Sigel said at the Conference on Retroviruses and Opportunistic Infections.

Previous studies had suggested that HIV infection was associated with a 2.5-fold to 3.6-fold increase in the risk of lung cancer.

Dr. Sigel of the Mount Sinai School of Medicine, New York, and his colleagues used data from the Veterans Aging Cohort Study (VACS), a “virtual” cohort of 33,420 HIV-positive individuals and 66,840 HIV-negative controls matched by age, race, gender, and site.

The VACS data set does not include information on smoking status. In order to control for smoking status, the investigators combined the VACS data set with data from the 1999 Large Health Survey of Veteran Enrollees. The merged dataset included 3,707 HIV-infected individuals and 9,980 healthy controls.

The median age of individuals in the cohort was 48 years, and 98% were male. Minorities were well represented: 41% were white, 39% were black, 10% were Hispanic, and 10% were of other races or ethnicities.

There were some significant baseline differences between HIV-infected and uninfected individuals in the cohort. HIV-infected individuals were more likely to be current daily smokers (32% vs. 28%), were more likely to be drug abusers (16% vs. 10%), and were more likely to have lung cancer at the beginning of the study (16 vs. 38 individuals). Individuals with prevalent lung cancer were excluded from the study.

The unadjusted absolute incidence of lung cancer was 26 cases/10,000 person-years among individuals who were HIV positive and 15 cases/10,000 person-years among individuals who were HIV negative.

Although the observed 80% increase in the risk of lung cancer associated with HIV infection was statistically significant, several other independent predictors conferred much larger risks of lung cancer. Current daily smoking was associated with a 9.8-fold increase in risk, and current occasional smoking was associated with a 3.4-fold increase in risk. Also, Hispanic ethnicity was associated with a 60% decrease in the risk of incident lung cancer.

“Our results represent a more modest risk than previous adjusted analyses, which may reflect differences in methods in our case identification, the presence of matched HIV controls for comparison within our cohort, or potentially greater precision allowed by our sample size,” Dr. Sigel said.