Abstract 110P
Background
In locally advanced rectal cancer (LARC), a high pre-treatment neutrophil-lymphocyte ratio (NLR) has been associated with poorer tumour response. Yet no studies have described the trend of NLR during neoadjuvant and adjuvant treatment for LARC and the correlations with clinicopathological factors. We hypothesized that NLR would be higher in smokers, poorer responders and those with a raised body mass index (BMI).
Methods
We examined NLR trends with a multilevel model for 29 prospective LARC patients across 6 timepoints throughout treatment: before neoadjuvant chemoradiation (T1), midpoint of chemoradiation (T2), post chemoradiation (T3), post-surgery (T4), midpoint of adjuvant chemotherapy (T5) and chemotherapy completion (T6). Variables collected included ethnic background, BMI, smoking status and pathological responses graded by Ryan tumour regression grade (TRG), ypT and nodal status.
Results
21 (72%) patients were male. Median age was 58 years. Asians comprised 52%. 13 (45%) patients had a smoking history. 21 (72%) patients had a BMI ≥ 25. 13 (45%) patients had TRG of 2-3 (poor response). 15 (52%) patients had ypT score of 0-2. 24 (83%) patients had no pathologic lymph nodes (ypN0). NLR increased at T2 (mean 4.4) and peaked at T4 post-surgery (mean 5.0) before declining at T6 at completion of chemotherapy (mean 3.5). Smokers had a higher but non-significant NLR at all timepoints except T1. NLR was higher in Caucasian patients at T2 to T5 and statistically significant at T2 (p = 0.013). There were no statistical differences in NLR between BMI, TRG and ypT subgroups. ypN0 patients had a higher NLR at all timepoints and were statistically significant at T5 (p = 0.04) and T6 (p = 0.002).
Conclusions
In LARC patients, NLR falls with adjuvant chemotherapy. Smokers and Caucasian patients exhibited a trend for higher NLR, consistent with the association between smoking and systemic inflammation and potential ethnic variations in blood cell indices. Contrary to our hypothesis, ypN0 status correlated with higher NLR. The impact of clinicopathological factors on NLR and its potential predictive utility for neoadjuvant and adjuvant therapy warrants ongoing evaluation.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.