Lung disease related to AIDS is an important factor in increasing the risk of lung cancer seen in people with HIV, US researchers report inAIDS. The study compared the incidence rates of lung cancer and the survival time of AIDS patients and HIV-negative individuals.
"We found that HIV infection alone was not an independent risk factor for lung cancer, but the amount of tobacco over time and AIDS, more episodes of pneumonia among HIV-infected adults were the main contributors to the development of lung cancer, "comment the authors.
The incidence of cancers associated with AIDS (especially Kaposi's sarcoma, non-Hodgkin lymphoma) markedly decreased since the introduction of effective antiretroviral therapy (HAART). However, several studies have reported increased incidence of lung cancer among people with HIV since the advent of HAART. It is unclear whether this increase is simply due to high smoking rates observed in people with HIV. There is some evidence that the immune suppression associated with HIV infection and pulmonary damage caused by infections such as AIDS-related pneumonia and PCP recurrent bacterial pneumonia may also be important risk factors for lung cancer.
Faced with such uncertainty, researchers designed a study to determine the incidence of risk and survival time for lung cancer factors among individuals enrolled in two longitudinal cohort studies of HIV infection, involving women (women HIV Study interdepartmental [ WIHS]) (n = 2549), men (multicenter AIDS cohort study [MACS]) (n = 4274]). Both population cohorts include a comparison of HIV-negative individuals at risk.
Patients were followed until September 2012. A total of 60 lung cancer incident (46 in people HIV, 14 in HIV negative participants) were recorded between coorte.r- participants The average age at diagnosis of lung cancer was 52 years among women with HIV and 51 years among HIV-negative women. For men, the average age of diagnosis was 50 years for those with HIV and 54 years for HIV-negative patients. All were smokers.
Overall, the incidence of lung cancer was significantly higher among women (IRR = 151,8 100.000 by) than men (IRR = 50,7 100.000 by) (p <0,001). Incidence was higher among patients with HIV (IRR = 119 100.000 by) compared with HIV-negative individuals (IRR = 45 100.000 by) (p = 0,001).
All cases of lung cancer occur in smokers. Thirty-one of 60 cases occurred in people who had accumulated at least thirty years of prior history of smoking. (A pack year is equivalent to smoking 20 cigarettes per day for one year). Package of ten or more years of smoking was significantly associated with the incidence of lung cancer in a multivariate analysis.
HIV infection was not associated with a significantly increased risk of lung cancer when the two cohorts were analyzed separately. It was only when the two cohorts were combined that HIV has become significantly associated with risk of lung cancer (IRR = 2,64, 95% CI, 1.43-5.21).
After controlling for potential confounders, combined cohort analysis showed that factors independently associated with lung cancer were age, low educational level, the intensity of smoking and a prior diagnosis of AIDS-related pneumonia.
"We found that about two-thirds of the effect of HIV infection has been explained by a previous diagnosis of pneumonia," the authors comment about AIDS. "Inflammatory lung disease and infections were shown as a performance factor a role in the development of lung cancer in the general population, and this was also observed among HIV-infected individuals, particularly in association with recurrent pneumonia."
31canceres of lung among women diagnosed with HIV, 20 had a previous diagnosis of AIDS, 14 of which involved an AIDS-related pneumonia. Of 15 cases of lung cancer among men with HIV, six individuals involved with the previous diagnosis of AIDS, three of which involved pneumonia.
Survival data were available for patients 56 45 and during follow-up of these individuals died. The mean survival time for women was 9,5 months, whereas men survived for an average of six months. The analysis of all 56 patients showed that the only factor associated with longer survival after diagnosis was 2001. A history of injecting drug use was associated with lower survival.
The researchers then restricted the analysis to the 42 patients with lung cancer with HIV. The only factor related with HIV regardless associated with lung cancer survival was an index of CD4 count below 200 cells / mm3 (HR = 2,55, 95% CI, 1,09 5,0.95).
"Our data suggest that the lung damage and inflammation associated with HIV infection may be causing increased risk of lung cancer, the investigators conclude. But it also noted, "to encourage and help young HIV-infected smokers to quit and support smoking cessation is essential to reduce the burden of lung cancer in this population."
Published: December 22 2015 Translated by Claudio Souza's originalPrevious AIDS-related pulmonary disease associated with lung cancer risk for people with HIVReview Mara Macedo
Hessol NA et al.Lung cancer incidence and survival among HIV-infected and uninfected women and men. The AIDS 29: 1183-93, 2015.