Sustaining Blood Lymphocyte Count during Preoperative Chemoradiotherapy as a Predictive Marker for Pathologic Complete Response in Locally Advanced Rectal Cancer

Abstract

PurposeThe objective of this study was to explore the relationship between the circulating lymphocyte level during preoperative chemoradiotherapy (CRT) and pathologic complete response (pCR) in locally advanced rectal cancer.Materials and MethodsFrom May 2010 to May 2013, 52 patients treated with preoperative CRT followed by surgery, were analysed. Patients received conventional fractionated radiotherapy (50-54 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. Absolute blood lymphocyte counts and their relative percentage in total white blood cell counts were obtained from complete blood count tests performed prior to and after 4, 8, and 12 weeks of CRT. We analysed the association between achieving pCR and change in blood lymphocyte level during CRT, as well as clinical parameters.ResultsAmong 52 patients, 14 (26.9%) had evidence of pCR. Sustaining the blood lymphocyte count during CRT (lymphocyte count at 4 weeks/baseline lymphocyte count > 0.35; odds ratio, 8.33; p=0.02) and initial carcinoembryonic antigen < 4.4 ng/mL (odds ratio, 6.71; p=0.03) were significantly associated with pCR in multivariate analyses.ConclusionSustaining blood lymphocyte count during preoperative CRT was predictive for pCR in rectal cancer. Further studies are warranted to investigate the association between pathologic responses and circulating lymphocyte count with its subpopulation during preoperative CRT.

Peripheral and Tissue Lymphocytes as Predictors of Pathological Response in Locally Advanced Rectal Cancer Post Neoadjuvant Chemoradiotherapy

“…In our study we found that a high pre-CRT total lymphocytes count in the peripheral blood of rectal cancer patients was significantly associated with pathological response and high regression rate, and this as reported by Kitayama et al, Choi [24] who failed to find significant correlation between baseline blood lymphocyte counts with pCR and he explained this because they excluded patients with baseline lymphopenia from their study populations before preoperative CRT. Lymphopenia initially and lymphopenia as treatment effect has a negative prognostic value in various settings and malignancies [25] It was previously demonstrated that the densities of CD4(+) and CD8(+) tumor-infiltrating lymphocytes (TIL) had significant association with the histological grade after CRT, also in achieving CR post CRT and the density of CD8(+)…”

Radiation-related lymphopenia as a new prognostic factor in limited-stage small cell lung cancer

“…Despite the small number of patients (n=10) with a min ALC<297 cells/μL, min ALC was significantly related to poor survival in multivariate analysis (P=0.038). Two small studies on lymphopenia and tumor response during RT seem to support this data, but few studies have examined survival prediction by lymphopenia during RT [8,22]. Post ALC was the strongest predictor of OS and PFS in LS-SCLC (P=0.016 and P=0.01, respectively).…”

Nodal tumor response according to the count of peripheral blood lymphocyte subpopulations during preoperative chemoradiotherapy in locally advanced rectal cancer

“…Circulating lymphocyte count in peripheral blood was found to be an important parameter to determine clinical outcomes in advanced rectal cancer [5]. We also recently confirmed that sustaining lymphocyte count during preoperative CRT could be a predictive factor in rectal cancer [6]. …”

“…Each subpopulation of lymphocytes has different immune functions and different responses to CRT [14]. In a previous study, we showed that change in lymphocytes during CRT was associated with a pCR in locally advanced rectal cancer [6]. This result inspired us to evaluate the relationship between subpopulations of lymphocytes and tumor response.…”