Incidental lung cancers and positive computed tomography images in people living with HIV

Implementation of a lung cancer screening initiative in HIV-infected subjects

In this pilot program of low-dose computed tomography (LDCT) for the screening of lung cancer (LC) in a targeted population of people with HIV (PWH), its prevalence was 3.6%; the number needed to screen in order to detect one case of lung cancer was 28, clearly outweighing the risks associated with lung cancer screening. While data from additional cohorts with longitudinal measurements are needed, PWH are a target population for lung cancer screening with LDCT.

Interstitial Lung Abnormalities in People With HIV Infection and Uninfected Controls

BACKGROUND

Chest computed tomography (CT) findings in well-treated people with HIV infection (PWH) remain poorly characterized.

METHODS

Cross-sectional analysis examining interstitial chest CT findings in PWH (n = 754) and uninfected controls (n = 470).

RESULTS

HIV infection was independently associated with 1.82 (95% CI, 1.18-2.88) and 5.15 (95% CI, 1.72-22.2) higher adjusted odds of any interstitial lung abnormality and findings suspicious for interstitial lung disease, respectively.

CONCLUSIONS

HIV infection was independently associated with interstitial lung abnormalities and findings suspicious for interstitial lung disease. Whether these abnormalities develop into more recognizable disease states over time is unknown but warrants further investigation.

[How to reduce lung cancer mortality among people living with HIV?]

Lung cancer is the leading cause of cancer related death among people living with HIV (PLHIV). Tobacco exposure is higher among PLHIV (38.5%) and mainly explains the increased risk of lung cancer. To reduce lung cancer mortality, two approaches need to be implemented: lung cancer screening with low-dose thoracic CT scan and smoking cessation. Low dose CT scan is feasible in PLHIV. The false positive rate is not higher than in the general population, except for cases with CD4 <200/mm³. The impact on survival remains to be assessed. Despite the high prevalence, smoking cessation research among PLHIV is scarce. Very low quality data from 11 studies showed that more intensive smoking cessation interventions were effective in achieving short-term abstinence. A single randomized phase 3 trial showed the superiority of varenicline compared to placebo in long-term smoking cessation. The maximum benefit of reducing lung cancer mortality should be obtained by combining smoking cessation and lung cancer screening.

Computed tomography quantification of emphysema in people living with HIV and uninfected controls

People living with HIV (PLWH) may be more susceptible to the development of emphysema than uninfected individuals. We assessed prevalence and risk factors for emphysema in PLWH and uninfected controls. Spirometry and chest computed tomography scans were obtained in PLWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) study and in uninfected controls from the Copenhagen General Population Study (CGPS) who were >40 years. Emphysema was quantified using a low attenuation area < −950 Hounsfield units (%LAA-950) and the 15th percentile density index (PD15) and assessed by semi-quantitative visual scales. Of 742 PLWH, 21.2% and 4.7% had emphysema according to the %LAA-950 threshold with cut-offs at 5% and 10%, respectively. Of 470 uninfected controls, these numbers were 24.3% (p=0.23) and 4.0% (p=0.68). HIV was not associated with emphysema (adjusted OR 1.25, 95% CI 0.68–2.36 for %LAA-950 >10%) by PD15 or by visually assessed emphysema. We found no interaction between HIV and cumulative smoking. Breathlessness and sputum production were more common in PLWH with emphysema, and emphysema seemed to be more prevalent in PLWH with airflow limitation. HIV was therefore not independently associated with emphysema, but the clinical impact of emphysema was greater in PLWH than in uninfected controls.

[Lung cancer in HIV-infected patients]

Until 1996, AIDS was the leading cause of deaths from HIV infection. In 2010, because of introduction of powerful antiretroviral therapies, AIDS represented less than 25% of deaths. Cancer has become the leading cause of death in this population, and, because of smoking and immunosuppression, lung cancer risk is more important than in general population. Furthermore, treatment is more difficult, due to potential interactions between antiretroviral and anticancer therapies, to comorbidities and to tumor aggressiveness. Research will focus on molecular biology, immunotherapies and lung cancer screening in order to improve survival of HIV patients with lung cancer. For all these reasons, HIV patients must be included in clinical trials.