Immediate Versus Deferred Systemic Therapy in Patients With Mesothelioma

Area of Science:

• Oncology
• Thoracic Surgery
• Clinical Trials

Background:

• The 2018 ASCO guideline suggests expectant observation for asymptomatic, inoperable epithelioid malignant pleural mesothelioma (MPM) with low disease burden.
• Clinical characteristics and outcomes of MPM patients managed with initial observation and deferred treatment require evaluation.

Purpose of the Study:

• To evaluate clinical characteristics and outcomes in malignant pleural mesothelioma (MPM) patients managed with initial observation and deferred treatment initiation.
• To assess the impact of deferred systemic therapy on overall survival (OS) and progression-free survival (PFS) in selected MPM patients.

Main Methods:

• Retrospective collection of clinicodemographic and outcome data from patients with inoperable malignant pleural mesothelioma (MPM).
• Patients were categorized into two groups: immediate systemic treatment initiation versus observation with deferred treatment.
• Comparison of patient characteristics, treatment patterns, and survival outcomes between the immediate and deferred treatment groups.

Main Results:

• Of 222 advanced MPM patients, 15% (33 patients) were managed with deferred treatment.
• The deferred treatment group was older, less likely to have stage IV disease, and more often had epithelioid histology.
• Median overall survival (OS) was significantly longer in the deferred group (20.6 months) compared to the immediate treatment group (11.5 months); no significant difference in progression-free survival (PFS) was observed.

Conclusions:

• Deferral of systemic therapy and close observation may be a viable strategy for selected malignant pleural mesothelioma (MPM) patients.
• This approach did not negatively impact overall survival (OS) or physician-assessed progression-free survival (PFS) in this real-world analysis.