Gender Differences in Outcomes of Patients With Mesothelioma

Asbestos burden in lungs of non-occupationally exposed women from Broni (Pavia, Italy): a postmortem SEM-EDS study

Background

In Italy the incidence of malignant mesothelioma (MM) among women is remarkably high, due to the several contexts in which women had been exposed to asbestos. However, very few studies in literature focus on the inorganic lung content in women. The aim of this retrospective, observational study is to investigate the asbestos lung burden, in terms of concentration, dimensions and type of asbestos, in 42 women who died from MM and had been non-occupationally exposed to asbestos during the activity of the asbestos-cement plant located in Broni (Pavia, Northern Italy) where mainly chrysotile, crocidolite and amosite were used.

Methods

Lung samples taken during forensic autopsies have been digested using sodium hypochlorite and filtered through a cellulose-ester membrane. The filter was examined using a scanning electron microscope and the chemical composition of the fibers was analyzed using an electron dispersive spectroscopy. The number of detected inorganic fibers, asbestos fibers and asbestos bodies (ABs) were normalized to 1 gram of dry tissue.

Results

In six samples no asbestos has been detected. Overall, the most represented kind of asbestos was amosite, followed by crocidolite, tremolite/actinolite asbestos and chrysotile. The concentration of all inorganic fibers was significantly higher in women with environmental and household exposures compared with those with only environmental exposure (P=0.025), as well as the concentration of asbestos fibers (P=0.019) and ABs (P=0.049). We found a significant correlation between the concentration of asbestos fibers and the duration of exposure (rho =0.413, P=0.008), as well as with the latency of MM (rho =0.427, P=0.005). The distance of the residential address from the factory and the time spent daily in contact with asbestos did not influence the lung asbestos burden.

Conclusions

These results suggest the relevance of the lung clearance of asbestos, regarding mainly chrysotile. As a consequence, although scanning electron microscopy -energy dispersive X-ray spectroscopy (SEM-EDS) is considered the most reliable tool for assessing previous exposure to asbestos, its results should be interpreted with caution, especially in a legal context. In addition, our data confirm the relevance of environmental and household exposure in determining asbestos concentration in lungs and highlight the importance of household exposure.

A postmortem case control study of asbestos burden in lungs of malignant mesothelioma cases

BACKGROUND

Asbestos lung content is regarded as the most reliable tool for causal attribution of malignant mesothelioma (MM) to previous asbestos exposures. However, there is a lack of studies on asbestos burden in lungs of MM patients in comparison with healthy individuals. This study aims to provide such a comparison, investigating, as well, differences in asbestos lung burden with sex and time trends.

METHODS

Asbestos lung content has been assessed on formalin-fixed lung fragments using scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS) on individuals deceased from MM (cases) and healthy subjects without any lung disease who died from violent causes (controls) between 2005 and 2023.

RESULTS

Asbestos and asbestos bodies (ABs) were found, respectively, in 73.7% and 43.2% of cases and in 28 and 22% of controls; in MM cases the most represented asbestos types were crocidolite and amosite, whereas in controls it was tremolite-actinolite asbestos. The concentration of both asbestos fibers and ABs was statistically significantly higher in MM cases compared to controls. The mean asbestos fibers width was also significantly higher in cases than controls. Males and females with MM showed similar asbestos and ABs concentrations, but females had higher concentrations of chrysotile, and significantly lower fibers width compared to males. Time trends show that MM lung asbestos concentrations decreased starting in 2011.

DISCUSSION

The results suggest a correlation between asbestos burden in lungs and MM risk. The different concentration of chrysotile, as well as the different width of asbestos fibers in MM males and females might reflect a sex difference in response of the lung microenvironment to inhaled asbestos. Finally, this study provides the first pathological evidence of the effect of the ban of asbestos use, demonstrating a significant decrease of asbestos lung content after 2011.

Asbestos lung burden does not predicts survival in malignant pleural mesothelioma. A necropsy-based study of 185 cases

INTRODUCTION

Malignant pleural mesothelioma (MPM) is an asbestos-related disease with poor survival. The prognostic role of histological subtype is well established. Some studies (without a biological hypothesis) suggested that higher asbestos lung burden is associated with reduced survival.

OBJECTIVES

We performed a necropsy-based study of MPM patients to analyze the relationship between asbestos lung burden and survival.

METHODS

We selected subjects from two series of necropsies: residents in Brescia province (North-West Italy) and workers (or persons living with them) employed in the Monfalcone shipyards (North-East Italy). Asbestos fibers (AF) and bodies (AB) in lung samples were counted using a scanning electron and an optical microscope respectively. Separately in the two series, we analyzed median survival time and fitted multivariable Cox regression models (adjusted for gender, period and age at diagnosis, and morphology) to calculate hazard ratios (HR) and 95% confidence intervals (CI) for three levels of AF counts (reference: <1 million fibers per gram of dry lung tissue).

RESULTS

We analyzed 185 necropsies, 83 in Brescia and 102 in Monfalcone. Despite a much higher lung burden in Monfalcone patients, median survival was slightly shorter in Brescia (8.3 months) than in Monfalcone (10.2 months). In Brescia, for medium (1-9.9) and high (10+) fiber burden HRs were 0.91 (95% CI 0.54-1.53) and 1.23 (95% CI 0.41-3.70). In Monfalcone, the corresponding HRs were 1.18 (95% CI 0.59-2.35) and 1.63 (95% CI 0.77-3.45).

CONCLUSION

No relationship between asbestos lung burden and survival was found. Histological subtype was the strongest prognostic determinant.

Survival of Korean Patients with Malignant Pleural Mesothelioma Compensated for the Asbestos Injury Relief

Background: The purpose of this study was to identify the epidemiologic characteristics and prognostic factors for malignant pleural mesothelioma in Korea, which are currently insufficient. The data were derived from malignant mesothelioma patients who registered under the Asbestos Injury Relief Act; Methods: A total of 728 patients received compensation from the Asbestos Injury Relief Act due to malignant mesothelioma between 2011 and 2015. Of these, 313 patients (43.0%) with malignant pleural mesothelioma were included in the study. The study variables were sex (male, female), age at diagnosis (<59, 60–69, ≥70), smoking history (yes, no), surgery (yes, no), chemotherapy (yes, no), occupational exposure to asbestos (yes, no), and histological subtype (epithelioid, nonepithelioid); Results: Median survival of mesothelioma was 8.0 months (95% confidence interval: 6.2 to 9.8). The 1-year, 2-year, and 5-year survival rates (%) were 43.5%, 23.6%, and 12.5%, respectively. In multivariate analysis of Cox’s proportional hazards model; sex, age, smoking history, occupational asbestos exposure, and histological subtype were not significant prognostic factors, but surgery and chemotherapy combined was a significant predictor; Conclusions: Although the representativeness of these data is limited, our study estimates the epidemiologic characteristics of malignant pleural mesothelioma. Non-occupational exposure had a similar prognosis to occupational asbestos exposure, and there was no sex difference. In addition, it was found that receiving a combination of surgery and chemotherapy affects the survival rate, but there is a limitation in that factors such as performance status, comorbidities, and stage that contribute to survival are not considered.

Loculations and Associated Risk Factors of Childhood Pleural Tuberculosis

Background: Pleural loculation in childhood pleural tuberculosis (TB) remains a problem in practice, it is usually associated with failure drainage. Therefore, to improve the management of childhood pleural TB, a retrospective study was conducted to identify the risk factors associated with loculated effusion in childhood pleural TB. Methods: Between January 2006 and December 2019, consecutive children (≤15 years old) with tuberculous pleural effusion (definite and possible) were included for further analysis. The demographic, clinical, laboratory, and radiographic features were collected from the medical records. Univariate and multivariate logistic regressions were used to explore the factors associated with the presence of pleural loculation in children with pleural TB. Results: A total of 154 children with pleural TB (definite, 123 cases; possible, 31 cases) were included in our study and then were classified as loculated effusion (n = 27) and non-loculated effusion (n = 127) groups by chest X-ray or ultrasonography. Multivariate analysis revealed that male gender (age-adjusted OR = 3.903, 95% CI: 1.201, 12.683), empyema (age-adjusted OR = 4.499, 95% CI: 1.597, 12.673), peripheral monocytes ≤0.46 × 10⁹/L (age-adjusted OR = 4.122, 95% CI: 1.518, 11.193) were associated with the presence of loculated effusion in children with pleural TB. Conclusion: In conclusion, several characteristics, such as male gender, empyema, and peripheral monocyte count have been identified as risk factors for pleural loculation in children with pleural TB. Our findings may be helpful to improve the management of pleural loculation in childhood pleural TB.