Blood total lymphocyte count (TLC) before treatment had been reported to be play an important role in tumor immune response. The study aimed to evaluate whether the change of TLC was correlate with tumor regression grade (TRG) after neoadjuvant treatment in locally advanced rectal cancer patients.
TLC before and after neoadjuvant therapy were collected from available 307 patients in FOWARC study. The ratio of TLC reduction after neoadjuvant therapy was calculated. TRG 0-1 was defined as good responder. The correlation between TRG and the ratio of lymphocyte reduction was evaluated.
Of the 307 patients, 153 patients were good responder (TRG 0-1), and 154 had poor response (TRG 2-3). The base-line TLC before neoadjuvant therapy have no significant difference (p = 0.296) between good and poor responders. After neoadjuvant therapy, 85% of patients experienced TLC reduction. TLC after neoadjuvant treatment was lower in good response group than that of poor response group, with a median TLC of 1.08 and 1.29, respectively (p = 0.011). In the group with neoadjuvant chemotherapy alone, TLC reduction was more obvious in good responder. The median ratio of TLC reduction after neoadjuvant were 39.41% and 33.33% in good and poor responder group, respectively (p = 0.037).
|Items||Good response group||Poor response group|
|Ratio of TLC reduction of all 307 patients||36.00% ± 3.06%||36.00% ± 2.99%||32.00% ± 2.99%||16.00% ± 5.955|
|Ratio of TLC reduction in chemotherapy group||27.0% ± 4.16%||9.78% ± 5.16%||11.04% ± 3.58||5.06% ± 6.46%|
|TLC before neoadjuvant||2.003 ± 0.056||2.041 ± 0.048|
|TLC after neoadjuvant||1.263 ± 0.044||1.427 ± 0.056|
TLC reduction is more apparent in patients with good response after neoadjuvant treatment. The consumption of lymphocytes might indicate the immune response inside tumors after neoadjuvant treatment, which could be a predictor of sensitivity to preoperative therapy.
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All authors have declared no conflicts of interest.