UK Pemetrexed Trial Looks at Mesothelioma Prognostic Markers
The South West Area Mesothelioma and Pemetrexed (SWAMP) trial, ongoing in England, aims to examine different factors relating to malignant mesothelioma diagnosis, management, and outcomes. In a study published recently in the British Journal of Cancer, a research team followed 73 pleural mesothelioma patients (58 undergoing chemotherapy and 15 not receiving chemotherapy) for a minimum of 12 months. The team looked at patient radiographic marker and biomarkers to compare outcomes in the two groups. Outcomes were determined primarily by the endpoints time to progression (TTP) and overall survival (OS). Secondary endpoints were obtained by weighing patients’ TTP and OS against their biomarker levels at the start of the trial and following chemotherapy cycles.
The radiographic markers measured were linear pleural tumor measurement and tumor volume. They were measured using PET-CT scans. The biomarkers measured were neutrophil-lymphocyte ratio (NLR), mesothelin, and fibulin-3. They were obtained by blood samples.
Study results show that patients with a higher tumor volume had a significantly shorter median survival. Percentage change in tumor volume, however, was not significantly associated with survival or TTP. In other words, PET-CT strongly predicts mesothelioma patient survival, but does not indicate chemotherapy response.
A lower NLR was found to be an independent predictor of better survival and progression-free survival. Patients with NLR less than 4 had a median survival of 453 days compared to 257 days for patients with NLR greater than 4.
Mesothelin levels as measured pre-chemotherapy were not a significant predictor of survival, but falling mesothelin levels after chemotherapy were associated with longer TTP and longer OS. This suggests that mesothelin is useful for monitoring treatment response.
Fibulin-3 did not prove useful for predicting either survival or treatment response.
The researchers write that, “In summary, NLR is readily available in clinical practice and could assist clinicians when evaluating patients overall prognosis…There appears to be no role for routine interval PET-CT scan scanning in patients undergoing chemotherapy; however, change in serum mesothelin could be an indicator of treatment response and warrants further study.”
According to the researchers, malignant pleural mesothelioma remains universally fatal and has a median life expectancy of 9-14 months following diagnosis. Markers that predict prognosis and detect early treatment response in mesothelioma patients, they say, would enhance patient care.
You can read the full paper at nature.com.