Right-Sided Pleural Mesothelioma Versus Left-Sided Pleural Mesothelioma – Survival Time Differences

Malignant pleural mesothelioma (MPM) is a highly aggressive and rare type of asbestos-related cancer that develops from the pleura – a thin, shiny layer of membranous tissue that covers the lungs and the interior wall of the chest cavity. It carries a median survival of around 12-months post-diagnosis.

Sometimes, MPM develops on just one side of the chest and three studies have previously suggested that right-sided MPM is associated with poorer prognostic outcomes. Nonetheless, these studies were very small scale and estimates were not precise.

In order to test the hypothesis that patients with right-sided MPM experience a shorter life expectancy, a group of Turkish researchers analysed data pertaining to 5,064 cases in the US population that were tracked by the National Cancer Institute, between 1975-2003, under the Surveillance, Epidemiology, and End Results (SEER) Program.

A month ago, results were published as an abstract, in the Journal of Clinical Oncology.[i]

Parekh et al (2022) noted that the majority of patients found in the SEER database were male (81%), over 60 years of age (79.1%) and with mostly right-sided mesothelioma (58.9%). The average patient survival time in the study cohort was 8-months.

The researchers explored the association of clinical features (including tumour location) and mesothelioma-related death. The significance of laterality, as a prognostic indicator, was assessed at each stage of diagnosis.

Having made adjustments for age and gender, they discovered that right-sided MPM is an independent predictor of death in patients with regional/early-stage disease. In other words, they confirmed that right-sided involvement is independently associated with an increased risk of death in early-stage/localised sufferers.

The same could not be said for the cohort as a whole, i.e. accounting for distant spread/late-stage patients, for whom there was no statistically significant association between laterality and survival. The study authors reasoned that this lack of association could be explained by the overall shorter survival faced by the late-stage group.

Ultimately, research such as this latest clinical analysis should allow for more precise prognostication, which should in turn help consultants to make decisions regarding the most appropriate treatment options.


[i] Parkeh J et al., Laterality and survival in mesothelioma: A SEER database analysis. Journal of Clinical Oncology. 40, no. 16_suppl (June 01, 2022) e20594-e20594. <https://ascopubs.org/doi/pdf/10.1200/JCO.2022.40.16_suppl.e20594> accessed 13 July 2022.

Holly Zinc, ‘Is Right-Sided Pleural Mesothelioma Worse than Left-Sided?’ (29 June 2022 Surviving Mesothelioma) <https://survivingmesothelioma.com/is-right-sided-pleural-mesothelioma-worse-than-left-sided/> accessed 13 July 2022.