Predicting survival in malignant pleural mesothelioma using routine clinical and laboratory characteristics

Air pollution and survival in patients with malignant mesothelioma and asbestos-related lung cancer: a follow-up study of 1591 patients in South Korea

BACKGROUND

Despite significant advancements in treatments such as surgery, radiotherapy, and chemotherapy, the survival rate for patients with asbestos-related cancers remains low. Numerous studies have provided evidence suggesting that air pollution induces oxidative stress and inflammation, affecting acute respiratory diseases, lung cancer, and overall mortality. However, because of the high case fatality rate, there is limited knowledge regarding the effects of air pollution exposures on survival following a diagnosis of asbestos-related cancers. This study aimed to determine the effect of air pollution on the survival of patients with malignant mesothelioma and asbestos-related lung cancer.

METHODS

We followed up with 593 patients with malignant mesothelioma and 998 patients with lung cancer identified as asbestos victims between 2009 and 2022. Data on five air pollutants-sulfur dioxide, carbon monoxide, nitrogen dioxide, fine particulate matter with a diameter < 10 μm, and fine particulate matter with a diameter < 2.5 μm-were obtained from nationwide atmospheric monitoring stations. Cox proportional hazard models were used to estimate the association of cumulative air pollutant exposure with patient mortality, while adjusting for potential confounders. Quantile-based g-computation was used to assess the combined effect of the air pollutant mixture on mortality.

RESULTS

The 1-, 3-, and 5-year survival rates for both cancer types decreased with increasing exposure to all air pollutants. The estimated hazard ratios rose significantly with a 1-standard deviation increase in each pollutant exposure level. A quartile increase in the pollutant mixture was associated with a 1.99-fold increase in the risk of malignant mesothelioma-related mortality (95% confidence interval: 1.62, 2.44). For lung cancer, a quartile increase in the pollutant mixture triggered a 1.87-fold increase in the mortality risk (95% confidence interval: 1.53, 2.30).

CONCLUSION

These findings support the hypothesis that air pollution exposure after an asbestos-related cancer diagnosis can negatively affect patient survival.

Occupational and Environmental Asbestos Exposure and Survival of Patients with Asbestos-Related Cancer: A Follow-Up Study on Patients with Malignant Mesothelioma and Asbestos-Related Lung Cancer in Korea

Malignant mesothelioma and asbestos-related lung cancer are typically associated with a poor prognosis. However, it has been observed that some patients with these cancers survive significantly longer than the average survival period. While many preliminary studies have investigated factors influencing patient survival, the specific impact of asbestos exposure has not been thoroughly explored. We followed up with 546 patients with malignant mesothelioma and 902 patients with asbestos-related lung cancer, all identified as asbestos victims between 2009 and 2021. In both malignant mesothelioma and asbestos-related lung cancer, patients with occupational asbestos exposure exhibited not only shorter median survival times but also lower 3- and 5-year survival rates compared to those with environmental exposure. Additionally, a longer duration of occupational exposure and closer proximity to the source of asbestos were linked to shorter survival times and lower survival rates. Among the patients with occupational asbestos exposure, the highest hazard ratios (HRs) were observed in those who worked in the production of asbestos-containing products across both cancer types. In contrast, significant HRs were only noted in mesothelioma patients who lived near asbestos industries, slate houses, and redevelopment areas, within the environmentally exposed group.

CAMK2D: a novel molecular target for BAP1-deficient malignant mesothelioma

Malignant mesothelioma (MMe) is a rare but aggressive malignancy. Although the molecular genetics of MMe is known, including BRCA1-associated protein-1 (BAP1) gene alterations, the prognosis of MMe patients remains poor. Here, we generated BAP1 knockout (BAP1-KO) human mesothelial cell clones to develop molecular-targeted therapeutics based on genetic alterations in MMe. cDNA microarray and quantitative RT-PCR (qRT-PCR) analyses revealed high expression of a calcium/calmodulin-dependent protein kinase type II subunit delta (CAMK2D) gene in the BAP1-KO cells. CAMK2D was highly expressed in 70% of the human MMe tissues (56/80) and correlated with the loss of BAP1 expression, making it a potential diagnostic and therapeutic target for BAP1-deficient MMe. We screened an anticancer drugs library using BAP1-KO cells and successfully identified a CaMKII inhibitor, KN-93, which displayed a more potent and selective antiproliferative effect against BAP1-deficient cells than cisplatin or pemetrexed. KN-93 significantly suppressed the tumor growth in mice xenografted with BAP1-deficient MMe cells. This study is the first to provide a potential molecular-targeted therapeutic approach for BAP1-deficient MMe.

Factors affecting the life expectancy in malignant pleural mesothelioma: Our 10 years of studies and experience

Malignant pleural mesothelioma (MPM) is an aggressive tumor with a poor prognosis. In our study, we aimed to investigate the specific clinical, laboratory, and radiological features of the tumor and the prognostic effect of SUVmax (maximum standardized uptake values) according to PET/CT (positron emission tomography). Demographic, therapeutic, clinical, and survival information of patients diagnosed with histologically-validated pleural mesothelioma in our hospital between January 2010 to December 2019 will be retrospectively scanned from the hospital records. A total of 116 patients, 61 men (52.6%), and 55 women (47.4%), were analyzed. Thirty five patients (30.2%) were over the age of 65. Percentage of patients over 65 years of age, neutrophil count, and PET SUV Max values, asbestos exposure and pleural thickening rate were significantly higher in the deceased patients' group than in the living patients' group (P = .042, P = .039, P = .002, P = .004, P = .037). T stage (tumor stage), N stage (lymph nodes stage), metastasis stage, and Grade distribution were significantly higher in the deceased patients' group than in the living patients' group (P < .000, P < .000, P = .003, P < .000). The rates of chemotherapy and surgical treatment, right lung location, and epithelioid pathology were significantly lower in the deceased patients' group compared to the living patients' group (P = .016, P = .030, P = .018, P = .008). The mean follow-up time was 13 months. Key determinants of survival in MPM include age, male gender, neutrophil increase, pleural thickening, high PET SUV max values, stage, histological type, asbestos exposure, and treatment regimen.

Fibrosis in Mesothelioma: Potential Role of Lysyl Oxidases

Immunotherapies (such as checkpoint inhibitors) and standard chemotherapies (such as cisplatin) have limitations in the successful treatment of malignant pleural mesothelioma (MPM). Fibrosis is the accumulation of collagen in the extracellular matrix (ECM) of tissues, making them denser than that of healthy tissues and thereby affecting drug delivery and immune cell infiltration. Moreover, fibrosis severely affects the patient's breathing and quality of life. The production of collagen and its assembly is highly regulated by various enzymes such as lysyl oxidases. Many solid tumors aberrantly express the family of lysyl oxidases (LOX/LOXL). This review examines how LOX/LOXLs were found to be dysregulated in noncancerous and cancerous settings, discusses their roles in solid tumor fibrosis and pathogenesis and explores the role of fibrosis in the development and poor clinical outcomes of patients with MPM. We examine the current preclinical status of drugs targeting LOX/LOXLs and how the incorporation of such drugs may have therapeutic benefits in the treatment and management of patients with MPM.