Having a higher metabolic tumor volume (MTV) before starting therapy is associated with worse prognosis in patients with non-small cell lung cancer (NSCLC) who receive first-line treatment with pembrolizumab, according to research published in Cancers.
Higher MTV was associated with inferior progression-free survival (PFS) and overall survival (OS), researchers found. They also discovered that a higher bone marrow-to-liver ratio (BLR) was associated with poor prognosis.
For this study, the researchers retrospectively evaluated the clinical implications of quantitative biomarkers derived from pretreatment PET/CT scans in 85 patients who received first-line pembrolizumab alone (15 patients) or in combination with chemotherapy (70 patients).
The biomarkers assessed included total MTV, BLR, maximum and mean standardized uptake value, total lesion glycolysis, and spleen-to-liver ratio.
At a median follow-up of 12 months, patients with a lower MTV had significantly longer PFS and OS, as well as a significantly higher disease control rate (DCR).
The median PFS was 10 months for patients with an MTV of 70 mL or less and 4 months for patients with an MTV greater than 70 mL (P =.001). The median OS was not reached and 10 months, respectively (P =.004). The DCR was 81% and 53%, respectively (P =.007).
Patients with a lower BLR had significantly better PFS and OS but not DCR. The median PFS was 8 months for patients with a BLR of 1.06 or less and 4 months for patients with a BLR greater than 1.06 (P =.034). The median OS was 19 months and 6 months, respectively (P =.005). The DCR was 71% and 61%, respectively (P =.317).
The researchers noted that patients with an MTV greater than 70 mL had better prognosis if their BLR was 1.06 or less.
These results suggest that PET/CT-derived biomarkers can aid therapeutic decision-making in patients with NSCLC receiving immune checkpoint inhibitors (ICIs), according to the researchers.
They added that these findings have implications for clinical practice and made the following recommendations:
- PET/CT should be performed at baseline in all patients with advanced NSCLC receiving ICIs
- Patients with a high MTV should receive chemotherapy and ICIs in combination rather than ICIs alone
- Patients at risk for early progression, as identified by PET/CT-derived biomarkers, should be monitored more closely during initial therapy.
Lang D, Ritzberger L, Rambousek V, et al. First-line pembrolizumab mono- or combination therapy of non-small cell lung cancer: Baseline metabolic biomarkers predict outcomes. Cancers. Published online December 3, 2021. doi:10.3390/cancers13236096