Over the past several years, researchers have proposed a number of prognostic systems for patients with non-small cell lung cancer, many of which require extensive laboratory testing or genomic analysis. But it doesn’t have to be that complex, according to new research.

Researchers from The First Affiliated Hospital of Jinzhou Medical University in China identified a simple measure of systemic inflammation that effectively stratifies patients into three categories that predict disease-free and overall survival before surgery.

Non-small cell lung cancer. (Source: Creative Commons)

Accurate prognostic systems allow physicians to better select therapies to manage patients with NSCLC and enable patients to better understand their risks and make informed treatment decisions. Researchers dubbed the prognostic system COP-LMR (combination of platelet count and lymphocyte to monocyte ratio).

The study enrolled 1120 patients, 728 men and 392 women, with an average age of 60 years. Of those patients, 477 were stage I, 237 patients stage II and 406 stage IIIA. The system assigned 2 points to 138 patients with both a platelet count greater than 30x104 mm-3 and lymphocyte to monocyte ratio below 3.6, 1 point to the 459 with one of the factors, and 0 points to the 523 patients with neither factor.   

Over a median follow-up period of 45 months, 643 patients died and the five-year overall survival rate was 44.5%. COP-LMR score correlated strongly with five-year survival. The group of patients with a score of 2 had five-year survival of 21.9% compared to 39.4% and 54.8% for those with scores of 1 and 0, respectively. The scores also predicted disease-free survival as well as survival within groups of patients with tumors of the same pathological stage.

The researchers noted that tumor cells often induce platelet aggregation and previous studies have found that elevated platelet counts have predictive value in a variety of cancers. The lymphocyte to monocyte ratio provides an index of systemic inflammation. Higher lymphocytes levels indicate a stronger immune response to cancer, while elevated monocyte levels have been associated with poor outcomes in several malignancies. Monocytes are precursors of tumor-associated macrophages, high levels of which appear to promote angiogenesis, invasiveness and poor survival.

While neither platelets nor the lymphocyte to monocyte ratio alone serve as reliable independent prognostic factors, their combination did predict both disease-free survival and overall survival, according to the study.

The researchers concluded that “COP-LMR is easy to routinely assess because of its low cost and convenience. Moreover, repeat measurements of COP-LMR can be easily performed before and after surgery.”

They recommended that computed tomography and magnetic resonance imaging could be useful adjuncts to COP-LMR. As a measure that effectively divides NSCLC patients into three groups prior to surgery, COP-LMR provides a novel prognostic factor for survival after surgery, the researchers said.