Identifying factors to predict treatment prognosis in EGFR positive non-small-cell lung cancer

The authors examined whether the lymphocyte to monocyte ratio (LMR) could predict outcome in patients with late stage EGFR positive non-small-cell lung cancer (NSCLC). They concluded LMR could be beneficial in predicting outcome for patients with EGFR positive NSCLC patients receiving first-line EGFR-TKIs.  

Some types of non-small-cell lung cancer are caused by a genetic mutation (change) called EGFR. Treatments to target this mutation are called EGFR-TKIs. Treating EGFR NSCLC with EGFR-TKIs can improve survival for certain patients. It is important now for practitioners to be able to predict if this treatment would be beneficial for a patient.

Lymphocytes are immune cells that are important for tumor cell death. Monocytes are other immune cells that are associated with tumor growth. Studies have shown that a high lymphocyte to monocyte ratio (LMR) is predictive of outcome in patients undergoing other types of treatment. It is not clear whether LMR is predictive of the effectiveness of EGFR-TKIs for patients with early stage NSCLC.

This study looked at whether there is an association between LMR and potential effectiveness of EGFR-TKIs. 253 patients with late-stage EGFR NSCLC were included. These patients were treated with first-line EGFR-TKIs.

At baseline (beginning of trial), 153 patients had high LMR and 100 patients had low LMR. Patients were separated into three groups based on their LMR and 1-month-to-baseline ratio (MBR, a measure of how the LMR changed over the month). Group 1 included patients with high LMR and high MBR. Group 2 included patients with either high LMR or MBR. Group 3 included patients with low LMR and low MBR. LMR after 1 month of treatment was high for 118 patients and low for 33 patients. 

Overall, average progression free survival (PFS, time from beginning trial until disease progression) was 10.3 months. Average overall survival (OS, time from beginning trial until death) was 22 months.

For group 1 patients, average PFS was 15.4 months and average OS was 32.6 months.

For group 2 patients, average PFS was 7.1 months and average OS was 13.7 months.

For group 3 patients, average PFS was 2 months and average OS was 5.1 months.

The authors concluded that high LMR at baseline and during treatment could be a good indicator of better survival chances.