Can pretreatment platelet-to-lymphocyte and neutrophil-to-lymphocyte ratios predict long-term oncologic outcomes after preoperative chemoradiation followed by surgery for locally advanced rectal cancer?

PURPOSE

Systemic inflammation is associated with various malignancies, including colorectal cancer, as possible prognostic predictors. We aimed to evaluate the correlation of pretreatment the platelet-to-lymphocyte (PLR) and the neutrophil-to-lymphocyte (NLR) ratio with long-term oncologic outcomes and pathologic complete response (pCR) in locally ad vanced rectal cancer patients who received neoadjuvant concurrent chemoradiotherapy (CRT) followed by curative resection.

METHODS

Between October 1996 and December 2015, 168 rectal cancer patients treated with preoperative CRT followed by surgery were enrolled. The set cut-off/mean PLR and NLR were 170 and 2.8. We analyzed the relationship between PLR, NLR, and the 5-year overall survival (OS), disease-free survival (DFS), and pCR rate.

RESULTS

The 5-year OS rates were 75.9% and 59.8% in the highand low-PLR groups. The 5-year DFS rates were 62.9% and 50.8% in the high- and low-PLR groups, with no significant difference. In addition, the 5-year OS rates were 75.7% and 58.4%, and the 5-year DFS rates were 62.5% and 50.0% in the high- and low-NLR groups, respectively, both without any significant difference. Multivariate analysis showed only pretreatment PLR as an independent prognostic factor for OS (hazard ratio, 1.850; 95% confidence interval, 1.041-3.287; P=0.036), and both serologic markers were not independent prognostic factors for 5-year DFS.

CONCLUSION

Neither PLR nor NLR was associated with 5-year DFS nor pCR to neoadjuvant CRT. Only pretreatment PLR can be used in predicting OS in locally advanced rectal cancer patients who received neoadjuvant CRT followed by curative resection.