Prediction of the preoperative chemoradiotherapy response for rectal cancer by peripheral blood lymphocyte subsets

Predictive value of circulating lymphocyte subsets and inflammatory indexes for neoadjuvant chemoradiotherapy response in rectal mucinous adenocarcinoma patients: A machine learning approach

INTRODUCTION

In this study, we aimed to evaluate the predictive value of circulating lymphocyte subsets and inflammatory indexes in response to neoadjuvant chemoradiotherapy (NCRT) in patients with rectal mucinous adenocarcinomas (MACs).

METHODS

Rectal MAC patients who underwent NCRT and curative resection at Fujian Medical University Union Hospital's Department of Colorectal Surgery between 2016 and 2020 were included in the study. Patients were categorized into good and poor response groups based on their pathological response to NCRT. An independent risk factor-based nomogram model was constructed by utilizing multivariate logistic regression analysis. Additionally, the extreme gradient boosting (XGB) algorithm was applied to build a machine learning (ML)-based predictive model. Feature importance was quantified using the Shapley additive explanations method.

RESULTS

Out of the 283 participants involved in this research, 190 (67.1%) experienced an unfavorable outcome. To identify the independent risk factors, logistic regression analysis was performed, considering variables such as tumor length, pretreatment clinical T stage, PNI, and Th/Tc ratio. Subsequently, a nomogram model was constructed, achieving a C-index of 0.756. The ML model exhibited higher prediction accuracy than the nomogram model, achieving an AUROC of 0.824 in the training set and 0.762 in the tuning set. The top five important parameters of the ML model were identified as the Th/Tc ratio, neutrophil to lymphocyte, Th lymphocytes, Gross type, and T lymphocytes.

CONCLUSION

Radiochemotherapy sensitivity is markedly influenced by systemic inflammation and lymphocyte-mediated immune responses in rectal MAC patients. Our ML model integrating clinical characteristics, circulating lymphocyte subsets, and inflammatory indexes is a potential assessment tool that can provide a reference for individualized treatment for rectal MAC patients.

Programmed cell death ligand 1 expression on monocytes is inversely correlated with tumour response to preoperative chemoradiotherapy for locally advanced rectal cancer

AIM

The clinical efficacy of chemoradiotherapy (CRT) is largely dependent on host immune status. The aim of this study was to identify possible markers expressed on circulating mononuclear cells to predict tumour response in patients with locally advanced rectal cancer (LARC).

METHODS

Peripheral blood samples were obtained from 47 patients diagnosed with LARC before and after CRT. The numbers of lymphocytes and monocyte subsets were analysed using flow cytometry. Based on clinical and pathological findings, patients were classified as high or low responders.

RESULTS

Lymphocyte counts were markedly decreased after CRT. Total numbers of lymphocytes (p = 0.030) and CD4(+) T cells (p = 0.041) in post-CRT samples were significantly lower in low responders than in high responders. In contrast, monocyte counts were not reduced and the number of CD14^dim (+) CD16(+) nonclassical (patrolling) monocytes were somewhat increased after CRT (p = 0.050). Moreover, the ratios of programmed cell death ligand 1 (PD-L1) (+) cells on patrolling monocytes before and after CRT were significantly higher in low responders than in high responders (p = 0.0046, p = 0.0006). The same trend was observed for classical and intermediate monocytes. The expression of PD-L1 on patrolling monocytes before CRT correlated inversely with the number of T cells and natural killer (NK) cells after CRT. PD-L1(+) ratio in patrolling monocytes was an independent predictor for response to CRT.

CONCLUSION

Programmed cell death ligand 1 (PD-L1) expression on patrolling monocytes suppresses cell-mediated immunity in patients receiving CRT which could be related to tumour response, and may be a useful biomarker for decision-making in the management of patients with LARC.

Association of tumor deposits with tumor-infiltrating lymphocytes and prognosis in gastric cancer

Background

To investigate the relationship between tumor deposits (TDs) with the clinicopathological characteristics tumor-infiltrating lymphocytes (TILs) and prognosis of gastric cancer. Further analysis was done on the relationship between the number and maximum diameter of TDs with the clinicopathological characteristics and prognosis of gastric cancer.

Methods

The pathological findings of 369 patients with gastric cancer were retrospectively analyzed to observe the expression of TDs and the levels of stromal TILs. The relationship between TDs, clinicopathological characteristics, and levels of stromal TILs was compared using the chi-square test. Kaplan-Meier was used for survival analysis, and the log-rank test was used to determine the relationship between TDs and disease-free survival, cancer-specific survival, and overall survival. The prognostic value of TDs was assessed using multivariate Cox proportional hazards regression analysis. For further analysis, the optimal cutoff values for the number and maximum diameter of TDs were selected based on the receiver operating characteristic (ROC) curve.

Results

TDs were significantly associated with sex, lymphovascular invasion, perineural invasion, pathological T,N stage, and clinical stage (all P < 0.05). TILs levels are lower in TDs(+) group and higher in TDs(−) group. Compared with TDs(−) groups, TDs(+) group had poor disease-free survival, cancer-specific survival, and overall survival. TDs are negatively correlated with TILs, and TILs levels are lower in TDs(+) group and higher in TDs(−) group (P < 0.05). The samples are divided into the number of TDs (< 4 and ≥ 4) and the maximum diameter of TDs (< 7 mm and ≥ 7 mm). The number of TDs was significantly associated with pathological N stage (P < 0.05). The maximum diameter of TDs was significantly correlated with Lauren classification (P < 0.05) .TDs ≥ 4 had lower DFS, CSS, and OS (P < 0.05). The maximum diameter of TDs was not statistically significant with prognosis (P > 0.05).

Conclusion

TDs are independent prognosis predictors of gastric cancer. In the tumor microenvironment, TDs and TILs interact with each other to regulate the development of gastric cancer, thus affecting gastric cancer prognosis of patients. The number of TDs ≥ 4 has a worse prognosis compared to the number of TDs < 4.

Peripheral blood CD45RO+T cells is a predictor of the effectiveness of neoadjuvant chemoradiotherapy in locally advanced rectal cancer

To investigate the relationship between the changes in circulating CD45RO+T lymphocyte subsets following neoadjuvant therapy for rectal cancer in patients with locally advanced rectal cancer.The clinicopathological data of 185 patients with rectal cancer who received neoadjuvant therapy in the General Surgery Department of Beijing Chaoyang Hospital affiliated to Capital Medical University from June 2015 to June 2017 were analyzed. Venous blood samples were collected 1 week before neoadjuvant therapy and 1 week before surgery, and the expression of CD45RO+T was detected by flow cytometry. The receiver operating characteristic curve analysis was used to determine the optimal cut-off point of CD45RO+ratio. Log-rank test and multivariate Cox regression were used to analyze the overall survival rate (OS) and disease-free survival rate (DFS) associated with CD45RO+ratio.Circulating CD45RO+ratio of 1.07 was determined as the optimal cut-off point and CD45RO+ratio-high was associated with lower tumor regression grade grading (P = .031), T stage (P = .001), and tumor node metastasis (TNM) stage (P = .012). The 3-year DFS and OS rate in the CD45RO+ratio-high group was significantly higher than that in the CD45RO+ratio-low group (89.2% vs 60.1%, P<.001; 94.4% vs 73.2%, P<.001). The multivariate Cox analysis revealed that elevated CD45RO+ratio was an independent factor for better DFS (OR, 0.339; 95% CI, 0.153-0.752; P = .008) and OS (OR, 0.244; 95% CI,0.082-0.726; P = .011).Circulating CD45RO+ratio could predict the tumor regression grade of neoadjuvant therapy for rectal cancer, as well as long-term prognosis. These findings could be used to stratify patients and develop alternative strategies for adjuvant therapy.

Clinical significance of CD8+ and FoxP3+ tumor-infiltrating lymphocytes and MFG-E8 expression in lower rectal cancer with preoperative chemoradiotherapy

Preoperative chemoradiotherapy (CRT) for rectal cancer contributes to tumor down-staging and decreases locoregional recurrence. However, each patient shows a significantly different response to CRT. Therefore, the identification of predictive factors to CRT response would be beneficial to avoid unnecessary treatment. Cancer immunity in patients has been suggested to play an important role in the eradication of the tumor by CRT. In the present study, the utility of CD8⁺ and forkhead box P3 (FoxP3)⁺ tumor-infiltrating lymphocytes (TILs) and the expression of a novel immuno-regulatory factor, lactadherin (MFG-E8), in predicting CRT effectiveness in patients with rectal cancer was examined. A total of 61 patients with rectal cancer, who underwent curative resection following CRT were included in the study. The numbers of CD8⁺ and FoxP3⁺ TILs in a biopsy taken before CRT and MFG-E8 expression level in the specimens obtained at the time of the surgery after CRT were examined using immunohistochemical staining, and their association with clinicopathological characteristics, including patient survival, was determined. The tumors with more CD8⁺ TILs in the biopsy samples before CRT showed a significantly more favorable CRT response. The patients with tumors and a higher number of CD8⁺ TILs before CRT also exhibited significantly longer disease-free and overall survival times. Higher MFG-E8 expression level in post-CRT specimens was significantly associated with favorable CRT response; however, no significant association was found with any other clinicopathological characteristics, including survival time. The number of CD8⁺ TILs before CRT was a valuable predictor for CRT response and was associated with favorable prognosis in patients with lower rectal cancer and who were treated with CRT. High MFG-E8 expression level after CRT was also associated with a favorable CRT response.

Predicting pathological response to chemoradiotherapy for rectal cancer: a systematic review

Introduction: Pathological complete response (pCR) rates of approximately 20% following neoadjuvant long-course chemoradiotherapy for rectal cancer have given rise to non-operative or watch-and-wait (W&W) management. To improve outcomes there has been significant research into predictors of response. The goal is to optimize selection for W&W, avoid chemoradiotherapy in those who won't benefit and improve treatment to maximize the clinical complete response (cCR) rate and the number of patients who can be considered for W&W.Areas covered: A systematic review of articles published 2008-2018 and indexed in PubMed, Embase or Medline was performed to identify predictors of pathological response (including pCR and recognized tumor regression grades) to fluoropyrimidine-based chemoradiotherapy in patients who underwent total mesorectal excision for rectal cancer. Evidence for clinical, biomarker and radiological predictors is discussed as well as potential future directions.Expert opinion: Our current ability to predict the response to chemoradiotherapy for rectal cancer is very limited. cCR of 40% has been achieved with total neoadjuvant therapy. If neoadjuvant treatment for rectal cancer continues to improve it is possible that the treatment for rectal cancer may eventually parallel that of anal squamous cell carcinoma, with surgery reserved for the minority of patients who don't respond to chemoradiotherapy.

Clinical parameters predictive for sphincter-preserving surgery and prognostic outcome in patients with locally advanced low rectal cancer

Background

Although controversial, there are data suggesting that clinical parameters can predict the probability of sphincter preserving procedures in rectal cancer. The purpose of this study was to investigate the association between clinical parameters and the sphincter-preserving surgery rate in patients who had undergone neoadjuvant combination therapy for advanced low rectal cancer.

Methods

In this single center study, the charts of 540 patients with locally advanced rectal cancer who had been treated with induction chemotherapy-and/or neoadjuvant concomitant radiochemotherapy (nRCT) over an 11-year period were reviewed in order to identify patients with rectal cancer ≤6 cm from the anal verge, who had received the prescribed nRCT only. Univariate and multivariate analyses were used to identify pretreatment patient- and tumor associated parameters correlating with sphincter preservation. Survival rates were calculated using Kaplan-Meier analyses.

Results

Two hundred eighty of the 540 patients met the selection criteria. Of the 280 patients included in the study, 158 (56.4%) underwent sphincter-preserving surgery. One hundred sixty-four of 280 patients (58.6%) had a downsizing of the primary tumor (ypT < cT) and 39 (23.8%) of these showed a complete histopathological response (ypT0 ypN0). In univariate analysis, age prior to treatment, Karnofsky performance status, clinical T-size, relative lymphocyte value, CRP value, and interval between nRCT and surgery, were significantly associated with sphincter-preserving surgery. In multivariate analysis, age (hazard ratio (HR) = 1.05, CI95%: 1.02–1.09, p = 0.003), relative lymphocyte value (HR = 0.94, CI95%: 0.89–0.99, p = 0.029), and interval between nRCT and surgery (HR = 2.39, CI95%: 1.17–4.88, p = 0.016) remained as independent predictive parameters.

Conclusions

These clinical parameters can be considered in the prognostication of sphincter-preserving surgery in case of low rectal adenocarcinoma. More future research is required in this area.

Lymphocyte nadir predicts tumor response and survival in locally advanced rectal cancer after neoadjuvant chemoradiotherapy: Immunologic relevance

BACKGROUND AND PURPOSE

Neoadjuvant chemoradiation (nCRT) could reduce tumor infiltrating lymphocytes. We examined absolute lymphocyte count (ALC) nadir during nCRT, pathologic response and prognosis for locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

102 patients with LARC (cT3-4N0, or node-positive) treated between 2010 and 2015 with nCRT followed by complete resection were analyzed. The ALC value was obtained prior to, weekly during the treatment, and one month after nCRT. Associations of ALC nadir with immune cells' infiltrations, pathologic response and survival were analyzed.

RESULTS

Twenty-four (23.5%) and 60 (58.9%) patients achieved pathologic complete response and partial response respectively. Response rate was higher in high ALC nadir group than low nadir group (89.7% vs. 67.6%, p = 0.006). Compared to low ALC nadir group, increased tumor infiltrates of CD4+ (4% vs. 17.5%, p < 0.001), CD8+ (8% vs.30%, p < 0.001) T cells and CD68+ macrophages (6% vs. 25%, p < 0.001) were observed in high ALC nadir group. High ALC nadir [OR = 4.32 (95% CI, 1.22-15.26), p = 0.023] and well differentiation [OR = 10.53 (1.87-59.36), p = 0.008] were associated with pathologic response. Patients with high ALC nadir yielded better DFS [HR = 0.36 (0.16-0.81), p = 0.010] and OS [HR = 0.24 (0.08-0.69), p = 0.004].

CONCLUSIONS

Higher ALC nadir during nCRT is associated with a higher rate of pathologic response and better survival for LARC patients, suggesting that ALC may be a potential stratification strategy for LARC patients.

[Inflammatory and immune biomarkers of radiation response]

In radiotherapy, the treatment is adapted to each individual to protect healthy tissues but delivers most of time a standard dose according to the tumor histology and site. The only biomarkers studied to individualize the treatment are the HPV status with radiation dose de-escalation strategies, and tumor hypoxia with dose escalation to hypoxic subvolumes using FMISO- or FAZA-PET imaging. In the last decades, evidence has grown about the contribution of the immune system to radiation tumor response. Many preclinical studies have identified some of the mechanisms involved. In this context, we have realised a systematic review to highlight potential inflammatory and immune biomarkers of radiotherapy response. Some are inside the tumor microenvironment, as lymphocyte infiltration or PD-L1 expression, others are circulating biomarkers, including different types of hematological cells, cytokines and chemokines.

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

PURPOSE

The objective of this prospective study was to evaluate the relationship between the circulating lymphocyte subpopulation counts during preoperative chemoradiotherapy (CRT) and tumor response in locally advanced rectal cancer.

MATERIALS AND METHODS

From August 2015 to June 2016, 10 patients treated with preoperative CRT followed by surgery were enrolled. Patients received conventional fractionated radiotherapy (50.4 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. The absolute blood lymphocyte subpopulation was obtained prior to and after 4 weeks of CRT. We analyzed the association between a tumor response and change in the lymphocyte subpopulation during CRT.

RESULTS

Among 10 patients, 2 (20%) had evidence of pathologic complete response. In 8 patients with clinically node positive, 4 (50%) had nodal tumor response. All lymphocyte subpopulation counts at 4 weeks after CRT were significantly lower than those observed during pretreatment (p < 0.01). A high decrease in natural killer (NK) cell, count during CRT (baseline cell count - cell count at 4 weeks) was associated with node down staging (p = 0.034).

CONCLUSION

Our results suggest that the change of lymphocyte subset to preoperative CRT may be a predictive factor for tumor response in rectal cancer.

Outcomes of neoadjuvant chemoradiotherapy in Japanese locally advanced rectal carcinoma patients

Background

We investigated the efficacy and prognosis of neoadjuvant chemoradiotherapy (NACRT) for Japanese locally advanced rectal carcinoma patients.

Methods

Fifty-seven patients diagnosed with cT3-4 or any cT/cN+ disease using enhanced computed tomography or magnetic resonance imaging from 2002 to 2014 were enrolled. The male/female ratio was 42/15, and the median age was 67 years. Ra/Rb/Rb-P/P was expressed by 6/35/14/2 patients. Histological tumor types were tub1/tub2/por/muc in 22/30/4/1 patients. For NACRT, radiotherapy doses were 40–50.4 Gy chemotherapy consisted of 5′-DFUR, capecitabine, or S1.

Results

All 57 patients received curative surgical treatment. The anal preservation rate was 65.0 %. The ypStage of 0/I/II/IIIa/IIIb was 7/10/25/11/4 cases. The histological antitumor effect (HATE) was ≥grade (G) 2 and G3 in 31 (54.4 %) and 7 (12.3 %) cases, respectively. Postoperative complications occurred in 17 patients and exceeded GIII (Clavien–Dindo classification) in four patients. Recurrence was observed in 19 patients; the primary local recurrence rate was 5.3 %. The 3-year relapse-free survival (RFS) and overall survival (OS) rates were 64.8 and 95.5 %, respectively; the 5-year RFS and OS rates were 60.2 and 61.0 %, respectively. In multivariate analysis, ypN+ was a high-risk factor for distant organ recurrence. As predictive factors regarding the efficacy of NACRT, a neutrophil concentration <70 % and a neutrophil/lymphocyte ratio <3.0 in peripheral blood prior to treatment indicated that NACRT would be significantly more effective.

Conclusions

NACRT was effective in reducing local recurrence but did not suppress distant organ recurrence in Japanese locally advanced rectal carcinoma patients. A further investigation of an extension of the NACRT regimen is required.

Analysis of tumor-infiltrating gamma delta T cells in rectal cancer

AIM: To investigate the regulatory effect of Vδ1 T cells and the antitumor activity of Vδ2 T cells in rectal cancer.

METHODS: Peripheral blood, tumor tissues and para-carcinoma tissues from 20 rectal cancer patients were collected. Naïve CD4 T cells from the peripheral blood of rectal cancer patients were purified by negative selection using a Naive CD4⁺ T Cell Isolation Kit II (Miltenyi Biotec). Tumor tissues and para-carcinoma tissues were minced into small pieces and digested in a triple enzyme mixture containing collagenase type IV, hyaluronidase, and deoxyribonuclease for 2 h at room temperature. After digestion, the cells were washed twice in RPMI1640 and cultured in RPMI1640 containing 10% human serum supplemented with L-glutamine and 2-mercaptoethanol and 1000 U/mL of IL-2 for the generation of T cells. Vδ1 T cells and Vδ2 T cells from tumor tissues and para-carcinoma tissues were expanded by anti-TCR γδ antibodies. The inhibitory effects of Vδ1 T cells on naïve CD4 T cells were analyzed using the CFSE method. The cytotoxicity of Vδ2 T cells on rectal cancer lines was determined by the LDH method.

RESULTS: The percentage of Vδ1 T cells in rectal tumor tissues from rectal cancer patients was significantly increased, and positively correlated with the T stage. The percentage of Vδ2 T cells in rectal tumor tissues from rectal cancer patients was significantly decreased, and negatively correlated with the T stage. After culture for 14 d with 1 μg/mL anti-TCR γδ antibodies, the percentage of Vδ1 T cells from para-carcinoma tissues was 21.45% ± 4.64%, and the percentage of Vδ2 T cells was 38.64% ± 8.05%. After culture for 14 d, the percentage of Vδ1 T cells from rectal cancer tissues was 67.45% ± 11.75% and the percentage of Vδ2 T cells was 8.94% ± 2.85%. Tumor-infiltrating Vδ1 T cells had strong inhibitory effects, and tumor-infiltrating Vδ2 T cells showed strong cytolytic activity. The inhibitory effects of Vδ1 T cells from para-carcinoma tissues and from rectal cancer tissue were not significantly different. In addition, the cytolytic activities of Vδ2 T cells from para-carcinoma tissues and from rectal cancer tissues were not significantly different.

CONCLUSION: A percentage imbalance in Vδ1 and Vδ2 T cells in rectal cancer patients may contribute to the development of rectal cancer.

An 80-gene set to predict response to preoperative chemoradiotherapy for rectal cancer by principle component analysis

Preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer not only improves the postoperative local control rate, but also induces downstaging. However, it has not been established how to individually select patients who receive effective preoperative CRT. The aim of this study was to identify a predictor of response to preoperative CRT for locally advanced rectal cancer. This study is additional to our multicenter phase II study evaluating the safety and efficacy of preoperative CRT using oral fluorouracil (UMIN ID: 03396). From April, 2009 to August, 2011, 26 biopsy specimens obtained prior to CRT were analyzed by cyclopedic microarray analysis. Response to CRT was evaluated according to a histological grading system using surgically resected specimens. To decide on the number of genes for dividing into responder and non-responder groups, we statistically analyzed the data using a dimension reduction method, a principle component analysis. Of the 26 cases, 11 were responders and 15 non-responders. No significant difference was found in clinical background data between the two groups. We determined that the optimal number of genes for the prediction of response was 80 of 40,000 and the functions of these genes were analyzed. When comparing non-responders with responders, genes expressed at a high level functioned in alternative splicing, whereas those expressed at a low level functioned in the septin complex. Thus, an 80-gene expression set that predicts response to preoperative CRT for locally advanced rectal cancer was identified using a novel statistical method.