Impact of sidedness of colorectal cancer on tumor immunity

Does side matter? Deciphering mechanisms that underpin side-dependent pathogenesis and therapy response in colorectal cancer

Colorectal cancer (CRC) is stratified by heterogeneity between disease sites, with proximal right-sided CRC (RCRC) multifactorial in its distinction from distal left-sided CRC (LCRC). Notably, right-sided tumors are associated with aggressive disease characteristics which culminate in poor clinical outcomes for these patients. While factors such as mutational profile and patterns of metastasis have been suggested to contribute to differences in therapy response, the exact mechanisms through which RCRC resists effective treatment have yet to be elucidated. In response, recent analyzes, including those utilizing whole genome sequencing, transcriptional profiling, and single-cell analyses, have demonstrated that key molecular differences exist between disease sites, with differentially expressed genes spanning a diverse range of cellular functions. Here, we review and contextualize the most recent data on molecular biomarkers found to exhibit discordance between RCRC and LCRC, and highlight candidates for further investigation, including those which present promise for future clinical application. Given the present disparity in survival outcomes for RCRC patients, we expect the prognostic biomarkers presented in our review to be useful in establishing future directions for the side-specific treatment of CRC.

Comparison of circulating immune signatures across different consensus molecular subtypes (CMS) and between left- and right-sided lesions in stage II colorectal cancer using single-cell mass cytometry

BACKGROUND

Patients with stage II colorectal cancer (CRC) show considerable variability in prognosis. Circulating immune cells play a vital role in systemic tumor surveillance. This study aimed to determine the clinical significance of the frequency and phenotype of circulating immune cell subsets in patients with stage II CRC.

METHODS

We applied a 37-marker-cell-lineage-agnostic panel to perform single-cell mass cytometry on peripheral blood mononuclear cells (PBMCs) from 73 patients with stage II CRC and 21 patients with stage III CRC. To categorize the stage II patients into consensus molecular subtypes (CMS), we performed RNA sequencing on tumor and adjacent normal tissues from 51 of the 73 patients. We then compared the immune cell phenotypes and frequencies based on tumor location and CMS classification in patients with stage II CRC. Wilcoxon test was employed to compare the mean frequencies of cell clusters between different tumor locations. Krustal-Wallis analysis with post-hoc Dunn test was used to assess differences across multiple CMS groups.

RESULTS

Stage II CRC patients with left- and right-sided tumors, as well as in different CMS groups, exhibit significantly different tumor characteristics. Single-cell mass cytometry revealed profound interpatient variability in immune cell subpopulation distribution and phenotypes in PBMCs in stage II CRC. We identified unique T:monocyte complexes in the peripheral blood of patients with stage II CRC, with significantly higher frequencies in these patients compared to those with stage III CRC. Left- and right-sided stage II CRCs differed in peripheral immunity. Patients with right-sided CRC had significantly higher frequencies of circulating CD8+CD27-CD28- immunosenescent T cell subsets compared to patients with left-sided CRC. Significant variations were observed in the subpopulations of the T:monocyte complex, T cells, and monocytes across different CMS groups Patients with CMS1 tumors (immune-active) exhibited significantly higher frequencies of CD4+ central memory and CD8+ terminal effector T cell: classical monocyte complexes, as well as CD8+ terminal effector T cells in the circulation.

CONCLUSIONS

The frequency and phenotype of circulating immune cells are influenced by tumor side and CMS subtypes in stage II CRC. These observations provide a basis for further investigation into the mechanisms linking tumors and systemic immunity.

Role of mast cell in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

The pro-tumor effects of mast cell (MC) in the tumor microenvironment (TME) are becoming increasingly clear. Recently, MC were shown to contribute to tumor malignancy by supporting the migration of tumor-associated macrophages (TAMs), suggesting a relationship with tumor immunity. In the current study, we aimed to examine the correlation between MC infiltration and neoadjuvant chemoradiotherapy (nCRT) response for locally advanced rectal cancer (LARC). Ninety-five LARC patients who recieved nCRT were enrolled in this study. Protein levels of the MC marker tryptase and TAM marker CD206 were evaluated with immunohistochemistry (IHC). The correlation between MC infiltration and prognostic factors was evaluated. The effects of MCs on the malignant potential were examined using in vitro proliferation and invasion assays with a colorectal cancer (CRC) cell line (HCT-116). Following nCRT, 31.6% of resected LARC patient specimens were positive for MC infiltration by tryptase IHC analysis. MC infiltration was significantly correlated with nCRT response. The 5-year disease-free survival (DFS) rate was significantly lower in the MC-positive group compared with the MC-negative group (52.3% vs. 76.8%). Univariate and multivariate analyses revealed that MC infiltration was the independent prognostic indicator for DFS. MC infiltration was significantly correlated with CD206 expression, and therefore TAMs. In vitro experiments suggested that tumor activated mast cells could promote CRC cell malignant behavior via production of macrophage inhibitory factor. MC infiltration in LARC patients was positively correlated with TAM infiltration and resistance to nCRT, and was also an independent poor prognostic indicator.

Immunohistochemistry Expression of Programmed Death-Ligand 1 in Colorectal Carcinoma among Nigerians

BACKGROUND

Colorectal carcinoma (CRC) is the most common gastrointestinal malignancy in Nigeria with a dismal 5-year survival rate. Interactions between the CD8+ T-lymphocytes and the immune checkpoints such as cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed death-ligand 1 (PD-L1) expressions are important. Novel antibodies have been developed against these immune checkpoints and have been found to improve clinical outcome in many solid organ malignancies.

AIM

We aimed to determine immunohistochemical expression of PD-L1 in resected CRC cases assembled on tissue microarray blocks.

METHODS

Representative blocks and clinical information of resected CRC cases between 2010 and 2019 were retrieved from the archives of our department. Tissue microarray (6 × 4) blocks were constructed with 2 mm core needles. Immunohistochemistry using anti-PD-L1 rabbit monoclonal antibody (clone EPR19759 #213524, 1:200 Abcam, MA, USA) was carried out according to manufacturer's instruction.

RESULTS

The study included 170 cases, of which 144 cases had sufficient tissue for analysis. The peak incidence was observed in the 50-59 age group. Approximately 80.1% of the cases were in T3 and T4 stages. Only 8 (5.6%) out of 144 cases were positive for PD-L1. All the PD-L1 positive cases were either right-sided CRC (6/68) or rectal cancer (2/3). Of the seven positive cases with available histological grading, four were poorly differentiated/mucinous variants and three cases were moderately differentiated.

CONCLUSION

PD-L1 expression in CRC was low (5.6%) and showed strong associations with higher tumor grades (P < 0.013), right-sided tumors (P < 0.002), and rectal cancer. There was no association with age, tumor stage, and lymph node status.

PD-L1 Expression in Colorectal Carcinoma Correlates with the Immune Microenvironment

INTRODUCTION/BACKGROUND

Colorectal carcinoma (CRC) is a common malignancy, with its diverse clinical, pathological, and molecular features. The immune microenvironment of a tumor comprises of interplay between various cells and molecules, and has a significant role in deciding the tumor behavior and overall prognosis. PD-L1 (programmed cell death ligand-1) has been implicated in the regulation of the tumor immune microenvironment (TIME). There is limited data regarding the correlation of PD-L1 expression with immune cell profile in CRCs, especially in the Indian setting. The study aimed to assess the PD-L1 expression in CRC tumor cells and its association with TIME, mismatch repair (MMR), and various other clinicopathological parameters.

METHODS

This is a hospital-based, cross-sectional observational study. PD-L1 expression was assessed at the protein level by immunohistochemistry and mRNA level by qRT-PCR. Immune cell markers (CD4, CD8, CD20, FOXP3, and CD163) were interpreted using the ImageJ Fiji platform.

RESULTS

Of the 104 cases, 21% were PD-L1 positive and were more common in right-sided CRCs. PD-L1 positive cases showed significantly higher concentrations of all T-cell subsets (CD4+ , CD8+ , and FOXP3+), CD20+ B-cells, and CD163+ macrophages were noted. No statistical significance was seen between PD-L1 expression with clinical profile, pathological subtype, grade or stage, mismatch repair status (proficient vs deficient), and survival.

CONCLUSIONS

The present study showed a relatively lower frequency of PD-L1 in CRC from the Eastern Indian cohort. The immune cell concentration in the present study was calculated using image analysis-based objectivised methods. Significant correlation of PD-L1 expression in tumor cells with the tumor-infiltrating immune cells indicated its crucial role in the pathobiology of CRC especially by regulating the TIME. Considering the therapeutic implication of PD-L1 in various malignancies, it may be one of the crucial therapeutic targets in a proportion of cases.

Label-free quantification of imaging features in the extracellular matrix of left and right-sided colon cancer tissues

The molecular pathogenesis of colorectal cancer is known to differ between the right and left side of the colon. Several previous studies have focussed on the differences in clinicopathological features, proteomic and genetic biomarkers, the composition of gut microbiota, response to therapy, and the characteristics of the tumour microenvironment. However, the morphology and density of collagen in the extracellular matrix (ECM) have not been studied intensively. In this study, we employed 2-photon laser scanning microscopy (2PLSM) to visualise the intrinsic second-harmonic generation (SHG) signal emitted by collagen fibres in the heterogeneous ECM of human colon tumour tissues. Through texture analysis of the SHG signal, we quantitatively distinguished the imaging features generated by structural differences of collagen fibres in healthy colon and cancers and found marked differences. The fibres inside of tumours exhibited a loss of organisation, particularly pronounced in right-sided colon cancer (RSCC), where the chaotic regions were significantly increased. In addition, a higher collagen content was found in left-sided colon cancer (LSCC). In future, this might aid in subclassification and therapeutic decisions or even in designing new therapy regimens by taking into account the differences between collagen fibres features between colon tumours located at different sides.

Role of stromal PD-L1 expression in colorectal liver metastasis

BACKGROUND AND AIM

The outcomes of immune checkpoint blockade for colorectal cancer (CRC) treatment are unsatisfactory. Furthermore, the efficacy of immune checkpoint blockade for liver metastasis of various cancer is poor. Here, we investigated the relationship between stromal programmed death-ligand 1 (PD-L1) expression and the prognosis of patients with colorectal cancer liver metastasis (CRLM).

METHODS

The present study enrolled 84 CRLM patients who underwent surgery (R0) for CRC. Immunohistochemistry was performed to analyze stromal PD-L1 expression in CRLM.

RESULTS

Stromal PD-L1 was expressed in 52.3% of CRLM samples, which was associated with fewer not optimally resectable metastases (p = 0.04). Stromal PD-L1 also tended to associate with a lower tumor grade (p = 0.08). Stromal PD-L1-positive patients had longer overall survival (p = 0.003). Multivariate analysis identified stromal PD-L1 expression (p = 0.008) and poorer differentiation (p < 0.001) as independent prognostic indicators. Furthermore, stromal PD-L1 expression was correlated to a high number of tumor-infiltrating lymphocytes (TILs). Stromal PD-L1- and low TIL groups had shorter OS than stromal PD-L1 + and high TIL groups (46.6% vs. 81.8%, p = 0.05) Stromal PD-L1-positive patients had longer disease-free survival (DFS) (p = 0.03) and time to surgical failure (p = 0.001). Interestingly, stromal PD-L1 expression was positively related to the desmoplastic subtype (p = 0.0002) and inversely related to the replacement subtype of the histological growth pattern (p = 0.008).

CONCLUSIONS

Stromal PD-L1 expression may be a significant prognostic marker for CRLM.

Multicenter study of prognostic factors in paraaortic lymph node dissection for metastatic colorectal cancer

Purpose

The role of paraaortic lymph node dissection (PALND) in colorectal cancer (CRC) has been less evaluated than surgical treatments for other distant metastases. We evaluated surgical outcomes after PALND and identified prognostic factors.

Methods

The medical records of patients who underwent PALND for paraaortic lymph node metastasis (PALNM) were reviewed retrospectively. All patients were categorized into the M1a group (isolated PALNM, n = 27), and the M1bc group (distant metastases other than PALNM, n = 26). Three severity factors (PALNM-SF: number of harvested paraaortic lymph nodes [hLN], ≥14; number of metastatic paraaortic lymph nodes [mLN], ≥5; and lymph nodes ratio [mLN/hLN], ≥0.5) were defined to determine their effects on survival.

Results

The 5-year overall survival (OS) of the M1a and M1bc groups were 61.1% and 6.4%, respectively (P = 0.0013). The 5-year disease-free survival (DFS) of the M1a group was 47.4%, and the 3-year DFS of the M1bc group was 9.1% (P < 0.001). Patients with 2 or more PALNM-SFs showed worse OS than those with 1 PALNM-SF (P = 0.017). In multivariate analysis, M1bc (non-isolated PALNM) was the only significant factor for survival. In the M1a group, patients with 2 or more PALNM-SFs showed significantly worse survival than those with a single PALNM-SF. In multivariate analysis, 2 or more PALNM-SF was a significant factor for survival.

Conclusion

PALND for CRC provided favorable outcomes in the survival of an isolated PALNM, although this was uncertain for non-isolated PALNMs. The PALNM-SFs helped assess the prognosis after PALND.

Impact of Postoperative Naples Prognostic Score to Predict Survival in Patients with Stage II-III Colorectal Cancer

BACKGROUND

The Naples prognostic score (NPS) is a scoring system that reflects a patient's systemic inflammatory and nutritional status. This study aimed to evaluate whether postoperative NPS is effective in assessing the prognosis of stage II-III colorectal cancer (CRC) patients compared with preoperative NPS.

METHODS

Between 2005 and 2012, a total of 164 patients diagnosed with stage II-III CRC, who underwent curative resection followed by adjuvant chemotherapy, were divided into two groups: Group 0-1 (NPS = 0-2) and Group 2 (NPS = 3 or 4). Preoperative NPS was calculated based on the results before surgeries, and postoperative NPS was assessed using the results obtained before adjuvant chemotherapy.

RESULTS

The overall survival of Group 0-1 was higher than that of Group 2 in both pre- and postoperative NPS assessments. According to the ROC curve analysis, the Area Under the Curve (AUC) ratio for postoperative NPS was 0.64, compared with 0.57 for preoperative NPS, 0.52 for the preoperative neutrophil-lymphocyte ratio (p = 0.032), and 0.51 for the preoperative platelet-lymphocyte ratio (p = 0.027).

CONCLUSIONS

Postoperative NPS is effective in predicting the prognosis of stage II-III CRC patients who underwent curative resection followed by adjuvant chemotherapy. The use of NPS could be beneficial in evaluating the prognosis of CRC patients after surgeries.

Laterality influence on gene expression of DNA damage repair in colorectal cancer

Colorectal carcinoma (CRC) is the third most common malignancy worldwide, and second in number of deaths in the world. The molecular pathogenesis of CRC is heterogeneous and can affect several genes. Moreover, genomic instability is recognized as an important part of CRC carcinogenesis and is tightly connected to DNA damage response. DNA damage repair (DDR) pathways are intrinsically associated with cancer development and establishment. Traditionally, CRC is considered as one coherent disease, however, new evidence shows that left and right-sided CRC present differences observed in clinical settings, as well as in pre-clinical studies. Therefore, this study aimed to investigate the impact of DDR transcriptional profiles on survival in different sublocations of the colon and rectum using Cox regression, survival analysis and differential gene expression. Right side colon (RSC) has DDR genes' expression associated only with higher risk of death, while left side colon (LSC) and Rectum have most genes' expression associated with lower risk. The pattern is the same with survival analysis. All significant DDR genes had lower expression associated with better survival in RSC, as opposed to LSC and Rectum. Our results demonstrate that RSC is distinctively different from LSC and Rectum. LSC and Rectum have similar DDR expression profiles.

Role of IDO expression in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND

The role of the immune system in locally advanced rectal cancer (LARC) following preoperative chemoradiotherapy (CRT) has been widely investigated in recent years. This study examined the prognostic significance of indoleamine-pyrrole 2,3-dioxygenase (IDO) expression in patients with LARC who received preoperative CRT.

METHODS

Ninety patients with LARC who underwent preoperative CRT and curative resection were enrolled. IDO and programmed death-ligand 1 (PD-L1) expression was evaluated by immunohistochemistry.

RESULTS

Clinicopathological factors did not significantly differ between patients with positive or negative IDO expression, excluding the correlation of positive IDO expression with better tumor differentiation (p = 0.02). IDO expression was not associated with pathological response (p = 0.44), but it was associated with PD-L1 expression. The 5-year overall survival (OS) rate was significantly worse in the IDO-positive group than in the IDO-negative group (64.8% vs. 85.4%, p = 0.02). Univariate analysis identified IDO and PD-L1 expression (p = 0.02), surgical procedure (p = 0.01), final pathological stage (p = 0.003), lymph node metastasis (p < 0.001), and lymphatic invasion (p = 0.002) as significant prognostic factors for OS. Multivariate analysis revealed that IDO expression (HR: 7.10, p = 0.0006), surgical procedure (HR: 5.03, p = 0.01), lymph node metastasis (HR: 2.37, p = 0.04) and lymphatic invasion (HR: 4.97, p = 0.01) were independent prognostic indicators. Disease-free survival was not correlated with IDO or PD-L1 expression.

CONCLUSIONS

IDO expression in patients with LARC who received preoperative CRT could be a potential prognostic indicator. IDO expression could be a useful marker for specifying individual treatment strategies in LARC.

CXCL8 expression is associated with advanced stage, right sidedness, and distinct histological features of colorectal cancer

CXCL8 is an inflammatory chemokine elevated in the colorectal cancer (CRC) tumour microenvironment. CXCR2, the major receptor for CXCL8, is predominantly expressed by neutrophils. In the cancer setting, CXCL8 plays important roles in neutrophil chemotaxis, facilitating angiogenesis, invasion, and metastasis. This study aimed to assess the spatial distribution of CXCL8 mRNA expression in CRC specimens, explore associations with clinical characteristics, and investigate the underlying biology of aberrant CXCL8 levels. CXCR2 expression was also assessed in a second cohort of unique CRC primary tumours and synchronously resected matched liver metastases. A previously constructed tissue microarray consisting of a cohort of stage I-IV CRC patients undergoing surgical resection with curative intent (n = 438) was probed for CXCL8 via RNAscope®. Analysis was performed using HALO® digital pathology software to quantify expression in the tumour and stromal compartments. Scores were assessed for association with clinical characteristics. Mutational analyses were performed on a subset of these patients to determine genomic differences in patients with high CXCL8 expression. A second cohort of stage IV CRC patients with primary and matched metastatic liver tumours was stained via immunohistochemistry for CXCR2, and scores were assessed for clinical significance. CXCL8 expression within the stromal compartment was associated with reduced cancer-specific survival in the first cohort (p = 0.035), and this relationship was potentiated in right-sided colon cancer cases (p = 0.009). High CXCL8 within the stroma was associated with driving a more stromal-rich phenotype and the presence of metastases. When stromal CXCL8 scores were combined with tumour-infiltrating macrophage counts or systemic neutrophil counts, patients classified as high for both markers had significantly poorer prognosis. CXCR2+ immune cell infiltration was associated with increased stromal invasion in liver metastases (p = 0.037). These data indicate a role for CXCL8 in driving unfavourable tumour histological features and promoting metastases. This study suggests that inhibiting CXCL8/CXCR2 should be investigated in patients with right-sided colonic disease and stroma-rich tumours.

The Role of Tumor Microenvironment and Immune Response in Colorectal Cancer Development and Prognosis

Colorectal cancer (CRC) is one of the most common cancers worldwide. The patient’s prognosis largely depends on the tumor stage at diagnosis. The pathological TNM Classification of Malignant Tumors (pTNM) staging of surgically resected cancers represents the main prognostic factor and guidance for decision-making in CRC patients. However, this approach alone is insufficient as a prognostic predictor because clinical outcomes in patients at the same histological tumor stage can still differ. Recently, significant progress in the treatment of CRC has been made due to improvements in both chemotherapy and surgical management. Immunotherapy-based approaches are one of the most rapidly developing areas of tumor therapy. This review summarizes the current knowledge about the tumor microenvironment (TME), immune response and its interactions with CRC development, immunotherapy and prognosis.

TRIM29 is differentially expressed in colorectal cancers of different primary locations and affects survival by regulating tumor immunity based on retrospective study and bioinformatics analysis

Background

In colorectal cancer (CRC) patients, different primary tumor locations caused distinct prognosis and clinicopathological features. It is necessary to identify specific tumor markers according tumor site. Our previous work has identified differentially expressed genes between CRC and adjacent normal tissues, in which only TRIM29 was differently expressed between right colon cancer (RCC) and left colon cancer (LCC) patients. Rectal cancer (RECC) was not included in this latter study and the effects of TRIM29 on the survival with RCC and LCC patients were not investigated. This study further verified TRIM29 expression through Gene Expression Omnibus (GEO) database and our retrospective study. The role of TRIM29 on survival according tumor sites was also explored. Furthermore, the molecular mechanisms of TRIM29 were explored.

Methods

The GEO dataset was used to confirm the differential expression of TRIM29 in proximal and distal cancers. Moreover, TRIM29 were assess using immunohistochemistry (IHC) in 227 cases to observe the correlation between TRIM29 and tumor site. The relationship between TRIM29 and the clinicopathologic features was investigated according tumor sites. Furthermore, the disease-free survival (DFS) and overall survival (OS) was analyzed using the Kaplan-Meier method to assess the prognostic value of TRIM29. Finally, bioinformatics analysis was used to explore the molecular mechanisms. The Tumor-Immune System Interactions and Drug Bank database (TISIDB) was used to analyze the correlations between TRIM29 expression and tumor immune functions. The correlation of TRIM29 with tumor infiltrating lymphocytes or mismatch-repair-proficient/mismatch-repair-deficient (pMMR/dMMR) status was also investigated.

Results

TRIM29 expression was significantly higher in patients with RCC (P<0.001). RCC patients with high TRIM29 tended to be older, male, in stage III-IV, with N+ staging, and intestinal obstruction (P<0.001, P<0.001, P<0.001, P<0.001, and P=0.010, respectively). High TRIM29 expression was associated with an increased risk of recurrence/metastasis and death, only in RCC patients (P=0.020 and P<0.001). Functional annotations and immune activity analysis showed that TRIM29 is related to tumor infiltrating lymphocytes and immune dysfunction.

Conclusions

TRIM29 plays varying roles in patients with different tumor sites. TRIM29 is correlated with the clinicopathological features and prognosis in RCC patients. Indeed, TRIM29 may serve as a new biomarker for RCC patients.

Alterations of circulating lymphocyte subsets in patients with colorectal carcinoma

Introduction

Cellular immune response to cancer is known to be of great importance for tumor control. Moreover, solid tumors influence circulating lymphocytes, which has been shown for several types of cancer. In our prospective study we elucidate changes in lymphocyte subsets in patients with colorectal carcinoma compared to healthy volunteers.

Methods

Flow cytometry was performed at diagnosis of colon carcinoma to analyze B cells, T cells and NK cells including various subtypes of each group. Univariate and multivariate analyses including age, gender, tumor stage, sidedness and microsatellite instability status (MSI) were performed.

Results

Forty-seven patients and 50 healthy volunteers were included. Median age was 65 years in patients and 43 years in the control group. Univariate analysis revealed lower total lymphocyte counts, lower CD4 + cells, CD8 + cells, B cells and NKs including various of their subsets in patients. In multivariate analysis patients had inferior values of B cells, CD4 + cells and NK cells and various subsets, regardless of age and gender. Naïve, central memory and HLADR + CD8 + cells showed an increase in patients whereas all other altered subsets declined. MSI status had no influence on circulating lymphocytes except for higher effector memory CD8 + cells in MSI-high patients. Localization in the left hemicolon led to higher values of total cytotoxic T cells and various T cell subsets.

Conclusion

We found significant changes in circulating lymphocyte subsets in colon carcinoma patients, independent of physiological alterations due to gender or age. For some lymphocyte subsets significant differences according to tumor localization or MSI-status could be seen.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00262-021-03127-8.

Stromal tumor-infiltrating lymphocytes level as a prognostic factor for resected intrahepatic cholangiocarcinoma and its prediction by apparent diffusion coefficient

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) are a prognostic factor or an indicator of chemotherapy response for various malignancies. The aim of this study was to investigate the prognostic impact of TILs in resected intrahepatic cholangiocarcinoma (IHCC). We also investigated the usefulness of the apparent diffusion coefficient (ADC) in diffusion-weighted magnetic resonance imaging (DW-MRI) to predict TILs.

METHODS

We enrolled 23 patients with IHCC who underwent initial hepatic resection in Tokushima University Hospital from 2006 to 2017. We evaluated stromal TILs in the tumor marginal area and central area in surgical specimens. Patients were divided into low vs high stromal TILs groups. We analyzed the patients' clinicopathological factors, including prognosis, according to the degree of stromal TILs. We also analyzed the correlation between stromal TILs and the minimum ADC value.

RESULTS

Stromal TILs in the marginal area reflected overall survival more accurately than that in the central area. Additionally, marginal low TILs was significantly associated with lymph node metastasis and portal vein invasion. Both overall- and disease-free survival rates in the marginal low TILs group were significantly worse than those in the marginal high TILs group (P < 0.05). In the multivariate analysis, marginal low TILs were an independent prognostic factor for both overall- and disease-free survival (P < 0.05), and marginal low TILs were significantly associated with lower minimum ADC values (P < 0.02).

CONCLUSIONS

Stromal TILs, especially in the marginal area, might demonstrate prognostic impact in patients with IHCC. Moreover, the ADC values from MRI may predict TILs in IHCC tumor tissue.

Preoperative lymphocyte/C-reactive protein ratio and its correlation with CD8+ tumor-infiltrating lymphocytes as a predictor of prognosis after resection of intrahepatic cholangiocarcinoma

PURPOSE

To clarify whether the preoperative lymphocyte/C-reactive protein (CRP) ratio (LCR) is a prognostic factor for patients with intrahepatic cholangiocarcinoma (IHCC), and investigate its mechanism via tumor-infiltrating lymphocytes.

METHODS

The subjects of this retrospective study were 42 patients who had undergone hepatectomy for IHCC. We divided the patients into low LCR and high LCR groups (cutoff value: 8780) and analyzed their overall survival (OS) and disease-free survival (DFS) with respect to LCR and other clinicopathological factors. We also investigated the levels of stromal tumor-infiltrating lymphocytes (TILs) and CD8⁺ TILs in surgical specimens, and the relationship between LCR and TILs.

RESULTS

A low LCR was identified in 21 patients and was significantly correlated with older age, a high CRP-albumin ratio, and advanced disease stage, and was a prognostic factor for OS and DFS. Multivariate analysis revealed that a low LCR was an independent prognostic factor for worse OS (HR 10.40, P = 0.0077). Although the LCR and levels of stromal TILs were not significantly related, LCR and levels of CD8⁺ TILs were significantly related (P = 0.0297).

CONCLUSION

The preoperative LCR may predict the postsurgical prognosis of patients with IHCC and reflect the CD8⁺ TILs.

Colorectal Cancer, Gut Microbiota and Traditional Chinese Medicine: A Systematic Review

Based on the study and research on the pathogenesis of colorectal cancer, the types and functions of gut microbiota, and its role in guiding and regulating the occurrence and development of diseases, we have explored the mechanism of traditional Chinese medicine in the treatment of colorectal cancer by regulating the gut microbiota. Genetic variation, abnormal responses of innate and adaptive immunity, mucosal barrier dysfunction, imbalance of intestinal microbial colonization, personal and environmental risk factors are the main pathogenesis of colorectal cancer. The gut microbiota mainly includes Sclerotium (including Clostridium, Enterococcus, Lactobacillus and Ruminococcus) and Bacteroides (including Bacteroides and Prevotella), which have biological antagonism, nutrition for the organism, metabolic abilities, immune stimulation, and ability to shape cancer genes functions to body. The gut microbiota can be related to the health of the host. Current studies have shown that Chinese herbal compound, single medicinal materials, and monomer components can treat colorectal cancer by regulating the gut microbiota, such as Xiaoyaosan can increase the abundance of Bacteroides, Lactobacillus, and Proteus and decrease the abundance of Desulfovibrio and Rickerella. Therefore, studying the regulation and mechanism of gut microbiota on colorectal cancer is of great benefit to disease treatment.