Intertwined leukocyte balances in tumours and peripheral blood as robust predictors of right and left colorectal cancer survival

BACKGROUND

Colorectal cancer (CRC) accounts for 9.4% of overall cancer deaths, ranking second after lung cancer. Despite the large number of factors tested to predict their outcome, most patients with similar variables show big differences in survival. Moreover, right-sided CRC (RCRC) and left-sided CRC (LCRC) patients exhibit large differences in outcome after surgical intervention as assessed by preoperative blood leukocyte status. We hypothesised that stronger indexes than circulating (blood) leukocyte ratios to predict RCRC and LCRC patient outcomes will result from combining both circulating and infiltrated (tumour/peritumour fixed tissues) concentrations of leukocytes.

AIM

To seek variables involving leukocyte balances in peripheral blood and tumour tissues and to predict the outcome of CRC patients.

METHODS

Sixty-five patients diagnosed with colon adenocarcinoma by the Digestive Surgery Service of the La Paz University Hospital (Madrid, Spain) were enrolled in this study: 43 with RCRC and 22 with LCRC. Patients were followed-up from January 2017 to March 2021 to record overall survival (OS) and recurrence-free survival (RFS) after surgical interventions. Leukocyte concentrations in peripheral blood were determined by routine laboratory protocols. Paraffin-fixed samples of tumour and peritumoural tissues were assessed for leukocyte concentrations by immunohistochemical detection of CD4, CD8, and CD14 marker expression. Ratios of leukocyte concentration in blood and tissues were calculated and evaluated for their predictor values for OS and RFS with Spearman correlations and Cox univariate and multivariate proportional hazards regression, followed by the calculation of the receiver-operating characteristic and area under the curve (AUC) and the determination of Youden’s optimal cutoff values for those variables that significantly correlated with either RCRC or LCRC patient outcomes. RCRC patients from the cohort were randomly assigned to modelling and validation sets, and clinician-friendly nomograms were developed to predict OS and RFS from the respective significant indexes. The accuracy of the model was evaluated using calibration and validation plots.

RESULTS

The relationship of leukocyte ratios in blood and peritumour resulted in six robust predictors of worse OS in RCRC: CD8⁺ lymphocyte content in peritumour (CD8_pt, AUC = 0.585, cutoff < 8.250, P = 0.0077); total lymphocyte content in peritumour (CD4CD8_pt, AUC = 0.550, cutoff < 10.160, P = 0.0188); lymphocyte-to-monocyte ratio in peritumour (LMR_pt, AUC = 0.807, cutoff < 3.185, P = 0.0028); CD8⁺ LMR in peritumour (CD8MR_pt, AUC = 0.757, cutoff < 1.650, P = 0.0007); the ratio of blood LMR to LMR in peritumour (LMR_b/LMR_pt, AUC = 0.672, cutoff > 0.985, P = 0.0244); and the ratio of blood LMR to CD8⁺ LMR in peritumour (LMR_b/CD8MR_pt, AUC = 0.601, cutoff > 1.485, P = 0.0101). In addition, three robust predictors of worse RFS in RCRC were found: LMR_pt (AUC = 0.737, cutoff < 3.185, P = 0.0046); LMR_b/LMR_pt (AUC = 0.678, cutoff > 0.985, P = 0.0155) and LMR_b/CD8MR_pt (AUC = 0.615, cutoff > 1.485, P = 0.0141). Furthermore, the ratio of blood LMR to CD4⁺ LMR in peritumour (LMR_b/CD4MR_pt, AUC = 0.786, cutoff > 10.570, P = 0.0416) was found to robustly predict poorer OS in LCRC patients. The nomograms showed moderate accuracy in predicting OS and RFS in RCRC patients, with concordance index of 0.600 and 0.605, respectively.

CONCLUSION

Easily obtainable variables at preoperative consultation, defining the status of leukocyte balances between peripheral blood and peritumoural tissues, are robust predictors for OS and RFS of both RCRC and LCRC patients.

Comparative Study of Organoids from Patient-Derived Normal and Tumor Colon and Rectal Tissue

Colon and rectal tumors, often referred to as colorectal cancer, show different gene expression patterns in studies that analyze whole tissue biopsies containing a mix of tumor and non-tumor cells. To better characterize colon and rectal tumors, we investigated the gene expression profile of organoids generated from endoscopic biopsies of rectal tumors and adjacent normal colon and rectum mucosa from therapy-naive rectal cancer patients. We also studied the effect of vitamin D on these organoid types. Gene profiling was performed by RNA-sequencing. Organoids from a normal colon and rectum had a shared gene expression profile that profoundly differed from that of rectal tumor organoids. We identified a group of genes of the biosynthetic machinery as rectal tumor organoid-specific, including those encoding the RNA polymerase II subunits POLR2H and POLR2J. The active vitamin D metabolite 1α,25-dihydroxyvitamin D3/calcitriol upregulated stemness-related genes (LGR5, LRIG1, SMOC2, and MSI1) in normal rectum organoids, while it downregulated differentiation marker genes (TFF2 and MUC2). Normal colon and rectum organoids share similar gene expression patterns and respond similarly to calcitriol. Rectal tumor organoids display distinct and heterogeneous gene expression profiles, with differences with respect to those of colon tumor organoids, and respond differently to calcitriol than normal rectum organoids.

Plocabulin Displays Strong Cytotoxic Activity in a Personalized Colon Cancer Patient-Derived 3D Organoid Assay

Plocabulin is a novel microtubule-disrupting antitumor agent of marine origin that is currently undergoing phase II clinical trials. Plocabulin has potent antiproliferative and antiangiogenic actions in carcinoma cell lines and has antitumor activity in xenografted mice. Here, we used three-dimensional (3D) tumor organoids derived from three colorectal cancer (CRC) patients to study the effect of plocabulin in a personalized assay system that ensures dose dependence and high reproducibility. The cytotoxicity of plocabulin was an order of magnitude higher than that of the active irinotecan derivative SN38 (7-ethyl-10-hydroxy-camptothecin) in tumor organoids at different passages. Moreover, plocabulin maintained its strong cytotoxic activity in wash-out experiments, in which a short pulse treatment of tumor organoids was as efficient as continuous treatment. Our data show that plocabulin has a very potent cytotoxic action in CRC patient-derived tumor organoids, supporting ongoing clinical trials with plocabulin and the use of organoid assays to provide personalized validation of antitumor drugs.

Transanal access for rectal tumors: the simultaneous use of a flexible endoscope and SILS

The authors report that TEM with a single-incision laparoscopic surgery (SILS) port can be facilitated by the use of a colonoscope instead of a conventional laparoscopic camera. The colonoscope can be inserted through one of the SILS channels and has the added benefit of flexibility, insufflation, irrigation, suction, and an operative port.

[Transanal resection using a single port trocar: a new approach to NOTES]

INTRODUCTION

The morbidity and mortality, along with the functional changes that arise from radical surgery of rectal cancer, has led to an increasing interest in local treatment in the early stages of cancer of the rectum. Conventional transanal surgery has a high recurrence rate, for this reason transanal endoscopic microsurgery (TEM) is considered the treatment of choice in the last few years in large rectal adenomas and in early rectal cancer (low risk T1).

PATIENTS AND METHOD

We have intervened five patients, four with a diagnosis of villous adenoma of the rectum, and one in situ rectal carcinoma, using this new transanal approach, with a single port device.

RESULTS

The locations of the lesions were in the mid-rectum, at a mean distance of 9 cm (range 6-10) from the anal margin. All of them were situated in the posterior side. The resection margins were negative in all cases. The mean size of the adenomas was 4 cm, three being sessile shaped, and one with a short, thick pedicle (>1cm); the size of the carcinoma was 3 cm. The mean surgical time was 55 minutes. All the patients were discharged 48 hours after the surgical procedure.

CONCLUSION

We believe that the transanal endoscopic approach with a single port device is a simple, easily reproducible and cost-effective procedure when compared to TEM.