Podoplanin expression in cancer-associated fibroblasts predicts unfavourable prognosis in patients with pathological stage IA lung adenocarcinoma

Prognostic value of predominant subtype in pathological stage II-III lung adenocarcinoma with epidermal growth factor receptor mutation

OBJECTIVES

This study extracted clinicopathological features associated with recurrence and evaluated the tumor microenvironment in consecutive cases with resected pathological stage II-III epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (EGFR-mt).

METHODS

Between January 2008 and November 2018, we retrospectively reviewed 387 consecutive patients with pathological stage II-III lung adenocarcinoma who underwent surgical resection. We examined the EGFR mutation status (wild-type or mutant) and the evaluated clinicopathological features of all patients. In addition, tumor-promoting cancer-associated fibroblasts (CAFs), tumor-associated M2 macrophages (TAMs), and tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment of EGFR-mt cells were evaluated by immunohistochemical analysis.

RESULTS

EGFR-mt (n = 124, 32 %) had more lymph node and pulmonary metastases than EGFR-wild-type lung adenocarcinoma (EGFR-wt) despite the smaller invasive component size. The disease-free survival (DFS) of patients with EGFR-mt tended to be shorter than that of patients with EGFR-wt. In the analysis according to the predominant subtype, EGFR-mt with papillary-predominant subtype had a significantly shorter 5-year DFS than that of EGFR-wt with papillary-predominant subtype (15.3 % vs. 44.1 %, p < 0.01). We observed no significant differences among the other subtypes. Multivariate analysis of DFS in patients with EGFR-mt revealed that male sex, pathological stage III, lymph node metastasis, pulmonary metastasis in the same lobe and non-acinar and non-lepidic predominant subtypes (papillary, solid, or micropapillary) were independent poor prognostic factors. Immunohistochemical analysis of EGFR-mt revealed that non-acinar- and non-lepidic-predominant subtypes were associated with a higher frequency of podoplanin-positive CAFs (36 % vs. 13 %, p = 0.01) and a higher median number of CD204-positive TAMs (61 vs. 49, p = 0.07) compared to the acinar- or lepidic-predominant subtypes.

CONCLUSIONS

Non-acinar and non-lepidic predominant subtypes were predictors of recurrence and had an aggressive tumor microenvironment in pathological stage II-III EGFR-mt.

Expression Profile of Microenvironmental Factors in the Interface Zone of Colorectal Cancer: Histological-Stromal Biomarkers and Cancer Cell-Cancer-Associated Fibroblast-Related Proteins Combined for the Assessment of Tumor Progression

INTRODUCTION

The characterization of tumor microenvironment (TME) related factors and their impact on tumor progression have attracted much interest. We investigated cancer cells and cancer-associated fibroblasts (CAFs) to evaluate biomarkers that are associated with neoplastic progression, observing them in different interface zones of colorectal cancer.

METHODS

On 357 CRC tissue microarrays, using immunohistochemistry, we examined the associations of podoplanin and α-SMA expressed in cancer cells and CAFs and evaluated them in different areas: tumor core, invasive front, tumor budding, tumor-stroma ratio (TSR) scoring, and desmoplastic stroma.

RESULTS

CAFs expressing α-SMA were found in more than 90% of the cases. Podoplanin+ was detected in cancer cells and CAFs, with positivities of 38.6% and 70%, respectively. Higher α-SMA+ CAFs and podoplanin+ cancer cells were observed predominantly at the TSR score area: 94.3% and 64.3% of cases, respectively. The status of podoplanin in CAFs+ was higher in the desmoplastic area (71.6%). Stroma-high tumors showed increased expression of α-SMA and podoplanin in comparison with stroma-low tumors. The status of podoplanin in cancer cells was observed in association with lymphatic invasion and distant metastasis.

CONCLUSION

The substance of the CRC was composed predominantly of the surrounding stroma-α-SMA+ CAFs. Podoplanin expressed in the prognosticator zones was associated with unfavorable pathological features. The combination of histologic and protein-related biomarkers can result in a tool for the stratification of patients with CRC.

Detection, Role and Prognostic Value of Cancer-associated Fibroblasts in Colorectal Cancer

Cancer-associated fibroblasts (CAFs) - mesenchymal cells in the tumor stroma, play one of the leading roles in tumor progression in many different tumors, including colorectal cancer. Scientists have described many markers for CAFs, but none of them is specific. We performed immunohistochemistry tests using five antibodies (αSMA, POD, FAP, PDGFRα, PDGFRβ) to investigate CAFs in three zones of 49 colorectal adenocarcinomas: apical, central, and invasive edge. We revealed the reliable correlation between high PDGFRβ and PDGFRα value in the apical zone and deeper invasion (T3-T4) (p = 0.0281 and p = 0.0137). High αSMA level in apical zone (p = 0.0001), αSMA level in central zone (p = 0.019), POD level in apical zone (p = 0.0222), POD level in central zone (p = 0.0206) and PDGFRβ level in apical zone (p = 0.014) correlated reliably with the presence of metastasis in lymphatic nodules. For the first time, focused on the inner layer of CAF adjacent to tumor complexes. We observed that cases with inner αSMA expression were significantly more often (p = 0.023) characterized by the presence of regional lymph node metastasis compared with cases with mix of CAF markers (p = 0.007) and with cases with inner POD expression (p = 0.024). The found relationships between the level of markers and the presence of metastases indicate their clinical significance.

Research Progress on Therapeutic Targeting of Cancer-Associated Fibroblasts to Tackle Treatment-Resistant NSCLC

Non-small cell lung cancer (NSCLC) accounts for most lung cancer cases and is the leading cause of cancer-related deaths worldwide. Treatment options for lung cancer are no longer limited to surgery, radiotherapy, and chemotherapy, as targeted therapy and immunotherapy offer a new hope for patients. However, drug resistance in chemotherapy and targeted therapy, and the low response rates to immunotherapy remain important challenges. Similar to tumor development, drug resistance occurs because of significant effects exerted by the tumor microenvironment (TME) along with cancer cell mutations. Cancer-associated fibroblasts (CAFs) are a key component of the TME and possess multiple functions, including cross-talking with cancer cells, remodeling of the extracellular matrix (ECM), secretion of various cytokines, and promotion of epithelial-mesenchymal transition, which in turn provide support for the growth, invasion, metastasis, and drug resistance of cancer cells. Therefore, CAFs represent valuable therapeutic targets for lung cancer. Herein, we review the latest progress in the use of CAFs as potential targets and mediators of drug resistance for NSCLC treatment. We explored the role of CAFs on the regulation of the TME and surrounding ECM, with particular emphasis on treatment strategies involving combined CAF targeting within the current framework of cancer treatment.

Cancer-associated fibroblasts in breast cancer: Challenges and opportunities

The tumor microenvironment is proposed to contribute substantially to the progression of cancers, including breast cancer. Cancer-associated fibroblasts (CAFs) are the most abundant components of the tumor microenvironment. Studies have revealed that CAFs in breast cancer originate from several types of cells and promote breast cancer malignancy by secreting factors, generating exosomes, releasing nutrients, reshaping the extracellular matrix, and suppressing the function of immune cells. CAFs are also becoming therapeutic targets for breast cancer due to their specific distribution in tumors and their unique biomarkers. Agents interrupting the effect of CAFs on surrounding cells have been developed and applied in clinical trials. Here, we reviewed studies examining the heterogeneity of CAFs in breast cancer and expression patterns of CAF markers in different subtypes of breast cancer. We hope that summarizing CAF-related studies from a historical perspective will help to accelerate the development of CAF-targeted therapeutic strategies for breast cancer.

Prognostic Value of Podoplanin in Various Tumors

Background:

The prognostic significance of podoplanin (PDPN) in tumor cells for cancer patients’ survival remains controversial. Therefore, we performed this meta-analysis to clarify the relationship between the podoplanin-positive tumor cells and cancer prognosis.

Method:

Eligible studies were identified by searching the Pubmed and EBSCO online databases up to August 2019. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to evaluate the correlation between podoplanin expression and overall survival (OS) and/or disease-free survival (DFS) and odds ratios (ORs) with 95% CIs severed as the summarized statistics for clinicopathological characteristic.

Results:

A total of 2155 patients from 21 eligible studies were included. The results revealed that high expression of podoplanin was associated with a poor survival rate in cancer patients. Further subgroup analysis stratified by tumor type showed that podoplanin-positive tumor cell infiltration had a negative prognostic effect associated with survival in esophageal cancer and oropharyngeal cancer. In addition, high expression of these cells was significantly associated with N stage, T stage, TNM stage and vascular invasion.

Conclusion:

Our study suggests the over-expression of podoplanin might be a significant prognostic indicator for patients with esophageal and oropharyngeal cancer.

Podoplanin expression in cancer-associated fibroblasts predicts unfavorable prognosis in node-negative breast cancer patients with hormone receptor-positive/HER2 - negative subtype

BACKGROUND

Podoplanin expression in cancer-associated fibroblasts (CAFs) has been proposed as an indicator for poor prognosis in patients with invasive breast carcinomas, but little is known about its clinical significance in node-negative breast cancer patients with hormone receptor (HR) + /HER2  - subtype, who are expected to have a favorable prognosis.

METHODS

Immunohistochemical analyses were performed on 169 resected specimens of node-negative invasive carcinoma of no special type with HR + /HER2 - subtype using antibodies for podoplanin. When more than 10% of CAFs showed immunoreactivity with podoplanin as strong as that of internal positive controls, the specimens were judged as podoplanin-positive.

RESULTS

Podoplanin-positive status in CAFs was observed in 16.0% (27 of 169 cases) and it associated with high Ki67 labeling index (LI) (> 30%) (p = 0.03), higher stromal tumor-infiltrating lymphocytes (p < 0.001) and progesterone receptor-negative status (p = 0.045). Log-rank test showed that podoplanin-positive status in CAFs correlated with shorter disease-free survival (DFS) (p = 0.007) and disease-specific survival (DSS) (p < 0.001). Univariate analysis showed a significant correlation between shorter DFS and podoplanin-positive status in CAFs (hazard ratio [HR] = 3.380; p = 0.012), the presence of lymphatic invasion (HR = 5.621; p < 0.001), high Ki67 LI (HR = 5.217; p < 0.001), and histological grade III (HR = 3.748; p = 0.008). According to Cox multivariate analysis, podoplanin-positive status in CAFs had the most significant effect on shorter DSS (HR = 37.759; p = 0.003) followed by high Ki67LI (HR = 27.664; p = 0.007).

CONCLUSION

Podoplanin expression in CAFs could be an independent predictor for poor prognosis in node-negative breast cancer patients with HR + /HER2 - subtype.

Single-cell RNA sequencing reveals distinct tumor microenvironmental patterns in lung adenocarcinoma

Recent developments in immuno-oncology demonstrate that not only cancer cells, but also the tumor microenvironment can guide precision medicine. A comprehensive and in-depth characterization of the tumor microenvironment is challenging since its cell populations are diverse and can be important even if scarce. To identify clinically relevant microenvironmental and cancer features, we applied single-cell RNA sequencing to ten human lung adenocarcinomas and ten normal control tissues. Our analyses revealed heterogeneous carcinoma cell transcriptomes reflecting histological grade and oncogenic pathway activities, and two distinct microenvironmental patterns. The immune-activated CP²E microenvironment was composed of cancer-associated myofibroblasts, proinflammatory monocyte-derived macrophages, plasmacytoid dendritic cells and exhausted CD8+ T cells, and was prognostically unfavorable. In contrast, the inert N³MC microenvironment was characterized by normal-like myofibroblasts, non-inflammatory monocyte-derived macrophages, NK cells, myeloid dendritic cells and conventional T cells, and was associated with a favorable prognosis. Microenvironmental marker genes and signatures identified in single-cell profiles had progonostic value in bulk tumor profiles. In summary, single-cell RNA profiling of lung adenocarcinoma provides additional prognostic information based on the microenvironment, and may help to predict therapy response and to reveal possible target cell populations for future therapeutic approaches.

Expression of EMT-Related Genes in Hybrid E/M Colorectal Cancer Cells Determines Fibroblast Activation and Collagen Remodeling

Collagen, the main non-cellular component of the extracellular matrix (ECM), is profoundly reorganized during tumorigenesis and has a strong impact on tumor behavior. The main source of collagen in tumors is cancer-associated fibroblasts. Cancer cells can also participate in the synthesis of ECM; however, the contribution of both types of cells to collagen rearrangements during the tumor progression is far from being clear. Here, we investigated the processes of collagen biosynthesis and remodeling in parallel with the transcriptome changes during cancer cells and fibroblasts interactions. Combining immunofluorescence, RNA sequencing, and second harmonic generation microscopy, we have explored the relationships between the ratio of epithelial (E) and mesenchymal (M) components of hybrid E/M cancer cells, their ability to activate fibroblasts, and the contributions of both cell types to collagen remodeling. To this end, we studied (i) co-cultures of colorectal cancer cells and normal fibroblasts in a collagen matrix, (ii) patient-derived cancer-associated fibroblasts, and (iii) mouse xenograft models. We found that the activation of normal fibroblasts that form dense collagen networks consisting of large, highly oriented fibers depends on the difference in E/M ratio in the cancer cells. The more-epithelial cells activate the fibroblasts more strongly, which correlates with a dense and highly ordered collagen structure in tumors in vivo. The more-mesenchymal cells activate the fibroblasts to a lesser degree; on the other hand, this cell line has a higher innate collagen remodeling capacity. Normal fibroblasts activated by cancer cells contribute to the organization of the extracellular matrix in a way that is favorable for migratory potency. At the same time, in co-culture with epithelial cancer cells, the contribution of fibroblasts to the reorganization of ECM is more pronounced. Therefore, one can expect that targeting the ability of epithelial cancer cells to activate normal fibroblasts may provide a new anticancer therapeutic strategy.

Cancer-Associated Fibroblasts: Accomplices in the Tumor Immune Evasion

Simple Summary

A growing number of studies suggest that cancer-associated fibroblasts (CAFs) modulate both myeloid and lymphoid cells through secretion of molecules (i.e., chemical function) and production of the extracellular matrix (ECM), i.e., physical function. Even though targeting functions CAFs is a relevant strategy, published clinical trials solely aimed at targeting the stroma showed disappointing results, despite being based on solid preclinical evidence. Our review dissects the interactions between CAFs and immune cells and explains how a deeper understanding of CAF subpopulations is the cornerstone to propose relevant therapies that will ultimately improve survival of patients with cancer.

Abstract

Cancer-associated fibroblasts (CAFs) are prominent cells within the tumor microenvironment, by communicating with other cells within the tumor and by secreting the extracellular matrix components. The discovery of the immunogenic role of CAFs has made their study particularly attractive due to the potential applications in the field of cancer immunotherapy. Indeed, CAFs are highly involved in tumor immune evasion by physically impeding the immune system and interacting with both myeloid and lymphoid cells. However, CAFs do not represent a single cell entity but are divided into several subtypes with different functions that may be antagonistic. Considering that CAFs are orchestrators of the tumor microenvironment and modulate immune cells, targeting their functions may be a promising strategy. In this review, we provide an overview of (i) the mechanisms involved in immune regulation by CAFs and (ii) the therapeutic applications of CAFs modulation to improve the antitumor immune response and the efficacy of immunotherapy.

Machine learning-based histological classification that predicts recurrence of peripheral lung squamous cell carcinoma

BACKGROUND

Cancer tissue is composed of both a cancer cell component and a stromal component. The aim of this study was to investigate if the component ratio predicts a prognosis for lung squamous cell carcinoma (SqCC) patients by using a machine learning method.

METHODS

A total of 135 peripheral SqCC cases (tumor size: 3-5 cm) were enrolled in this study. The areas of the cancer cell component, the necrotic component, and the stromal component were accurately measured via a machine learning method. Each case was divided into the following three subtypes: 1) predominant cancer cell, 2) predominant necrosis, and 3) predominant stroma. The study examined if a particular subtype had prognostic significance.

RESULTS

The number of cases per subtype of predominant cancer cell, predominant necrosis, and predominant stroma was 59, 6, and 70, respectively. Patients with the predominant stroma subtype had a significantly shorter recurrence free survival (RFS) than did those with the predominant cancer cell subtype (5-yr RFS: 42.3 % vs. 84.3 %,p < 0.01). Also, in pathological stage I patients, the 5-year RFS rate for the predominant stroma subtype was significantly shorter (5-yr RFS: 64.3 % vs. 88.4 %, p < 0.01). In the multivariate analysis of p-stage I patients, the predominant stroma subtype was confirmed to be an independent prognostic factor for RFS (p < 0.01).

CONCLUSION

Using machine learning, the study confirmed that the predominant stroma subtype was an independent factor for RFS, suggesting that the ratio of the stromal component correlates with the malignant potential of SqCC.

Gene expression profiling by targeted RNA sequencing in pathological stage I lung adenocarcinoma with a solid component

OBJECTIVES

Solid predominant adenocarcinoma is considered an independent predictor of an unfavorable prognosis in patients with stage I lung adenocarcinoma (LUAD). Furthermore, solid minor components are related to poor prognosis in patients with stage I LUAD. Therefore, it is imperative to elucidate the molecular determinants of the malignant potential of solid components (SC). Several studies reported the gene expression profiling specific for lepidic predominant adenocarcinoma or solid predominant adenocarcinoma, however; there is no report identifying the differentially expressed genes (DEGs) between SC and acinar component (AC) within the same tumor tissue in pathological (p)-stage I LUAD patients.

MATERIALS AND METHODS

LUAD tissue samples containing both SC and AC were obtained from 8 patients with p-stage I LUAD and each component was microdissected. Targeted RNA sequencing was performed by a high-throughput chip-based approach.

RESULTS

In total, 1272 DEGs were identified, including 677 upregulated genes and 595 downregulated genes in SC compared with AC. The most highly upregulated gene was TATA binding protein associated factor 7 (TAF7) and the most highly downregulated gene was homeobox B3 (HOXB3), which acts as a metastasis suppressor. A protein-protein interaction (PPI) network analysis of upregulated genes in SC identified ribosomal protein S27a (RPS27a) as a hub gene with the highest degree. First neighbors of RPS27a included PSMA6, which is a highly promising target for lung cancer. The subnetwork of PD-L1 had 10 first neighbors, including CMTM6, which enhances the ability of PD-L1-expressing tumor cells to inhibit T cells. The staining score for PD-L1 in SC was significantly higher than that in AC by immunohistochemistry (p = 0.001).

CONCLUSION

Our results revealed several new DEGs and key PPI network in SC compared to AC, contributing to understanding the biological features of SC and providing therapeutic targets for early-stage LUAD with SC in the future.

Expression of Podoplanin in Sinonasal Squamous Cell Carcinoma and Its Clinical Significance

BACKGROUND

It was recently suggested that the upregulation of podoplanin (PDPN) in cancer cells plays a significant role in tumor invasion and metastasis and that it is significantly associated with poor prognosis in oral, cutaneous, and esophageal squamous cell carcinoma. The aim of this study was to investigate the expression pattern of PDPN in sinonasal squamous cell carcinoma (SNSCC) and to evaluate its role as a prognostic factor for survival outcome.

PATIENTS AND METHODS

This study included 59 subjects with SNSCC. We retrospectively collected the clinical features of these patients from medical records and retrieved the associated formalin-fixed, paraffin-embedded tissues for PDPN immunohistochemical staining. Furthermore, PDPN expression was analyzed in relation to the patients' clinicopathological features and prognosis.

RESULTS

We observed positive staining for PDPN in both cancer cells and stromal cancer-associated fibroblasts (CAFs). Positive expression of PDPN in cancer cells of patients with SNSCC was significantly correlated with the primary tumor site (p = 0.009) and local recurrence (p = 0.024). In addition, patients with PDPN-positive cancer cells had significantly lower overall survival (OS) and disease-free survival (DFS) rates than did patients with PDPN-negative cancer cells (both p < 0.05). Multivariate analysis revealed that PDPN expression in cancer cells was an independent prognostic factor for both OS (p = 0.038) and DFS (p = 0.039).

CONCLUSIONS

Our findings demonstrated that PDPN overexpression may be both an independent prognostic biomarker and a therapeutic target in SNSCC.

Thrombosis Risk Associated with Head and Neck Cancer: A Review

Venous thromboembolism (VTE) is a common complication for cancer patients. VTE-associated risk varies according to the type of tumor disease. Head and neck cancer is a common cancer worldwide, and most tumors are squamous cell carcinomas due to tobacco and alcohol abuse. The risk of VTE associated with head and neck (H&N) cancer is considered empirically low, but despite the high incidence of H&N cancer, few data are available on this cancer; thus, it is difficult to state the risk of VTE. Our review aims to clarify this situation and tries to assess the real VTE risk associated with H&N cancer. We report that most clinical studies have concluded that there is a very low thrombosis risk associated with H&N cancer. Even with the biases that often exist, this clinical review seems to confirm that the risk of VTE was empirically hypothesized. Furthermore, we highlight that H&N cancer has all the biological features of a cancer associated with a high thrombosis risk, including a strong expression of procoagulant proteins, modified thrombosis/fibrinolysis mechanisms, and secretions of procoagulant microparticles and procoagulant cytokines. Thus, this is a paradoxical situation, and some undiscovered mechanisms that could explain this clinical biological ambivalence might exist.

Inter- and intra-tumoural heterogeneity in cancer-associated fibroblasts of human pancreatic ductal adenocarcinoma

Cancer‐associated fibroblasts (CAF) are orchestrators of the pancreatic ductal adenocarcinoma (PDAC) microenvironment. Stromal heterogeneity may explain differential pathophysiological roles of the stroma (pro‐ versus anti‐tumoural) in PDAC. We hypothesised that multiple CAF functional subtypes exist in PDAC, that contribute to stromal heterogeneity through interactions with cancer cells. Using molecular and functional analysis of patient‐derived CAF primary cultures, we demonstrated that human PDAC‐derived CAFs display a high level of inter‐ and intra‐tumour heterogeneity. We identified at least four subtypes of CAFs based on transcriptomic analysis, and propose a classification for human PDAC‐derived CAFs (pCAFassigner). Multiple CAF subtypes co‐existed in individual patient samples. The presence of these CAF subtypes in bulk tumours was confirmed using publicly available gene expression profiles, and immunostainings of CAF subtype markers. Each subtype displayed specific phenotypic features (matrix‐ and immune‐related signatures, vimentin and α‐smooth muscle actin expression, proliferation rate), and was associated with an assessable prognostic impact. A prolonged exposure of non‐tumoural pancreatic stellate cells to conditioned media from cancer cell lines (cancer education experiment) induced a CAF‐like phenotype, including loss of capacity to revert to quiescence and an increase in the expression of genes related to CAF subtypes B and C. This classification demonstrates molecular and functional inter‐ and intra‐tumoural heterogeneity of CAFs in human PDAC. Our subtypes overlap with those identified from single‐cell analyses in other cancers, and pave the way for the development of therapies targeting specific CAF subpopulations in PDAC. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Podoplanin-positive cancer-associated fibroblasts predict poor prognosis in lung cancer patients

Background

Cancer-associated fibroblasts (CAFs) are a heterogeneous population, and different subpopulations play differential roles in tumor microenvironment. However, the prognostic role of podoplanin-positive CAFs in human lung cancer still remains controversial.

Methods

Herein, we performed a meta-analysis including 12 published studies with 1,802 patients identified from PubMed and EBSCO to assess the prognostic impact of podoplanin-positive CAFs in lung cancer patients.

Results

We found that podoplanin⁺ fibroblast infiltration significantly decreased overall survival (OS), disease-free survival (DFS), and progression-free survival in patients. In stratified analyses, podoplanin⁺ fibroblast infiltration was significantly associated with worse OS and DFS in both squamous cell carcinoma and adenocarcinoma of lung. In addition, high density of podoplanin-positive CAFs significantly correlated with unfavorable clinicopathological features such as lymph node metastasis, and lymphatic, vascular, and pleural invasion of patients.

Conclusion

Podoplanin⁺ fibroblast infiltration leads to worse clinical outcome in lung cancer patients, implicating that it is a valuable prognostic biomarker and targeting it may have a potential for effective treatment.

Generation of sphingosine-1-phosphate is enhanced in biliary tract cancer patients and is associated with lymphatic metastasis

Lymphatic metastasis is known to contribute to worse prognosis of biliary tract cancer (BTC). Recently, sphingosine-1-phosphate (S1P), a bioactive lipid mediator generated by sphingosine kinase 1 (SPHK1), has been shown to play an important role in lymphangiogenesis and lymph node metastasis in several types of cancer. However, the role of the lipid mediator in BTC has never been examined. Here we found that S1P is elevated in BTC with the activation of ceramide-synthetic pathways, suggesting that BTC utilizes SPHK1 to promote lymphatic metastasis. We found that S1P, sphingosine and ceramide precursors such as monohexosyl-ceramide and sphingomyelin, but not ceramide, were significantly increased in BTC compared to normal biliary tract tissue using LC-ESI-MS/MS. Utilizing The Cancer Genome Atlas cohort, we demonstrated that S1P in BTC is generated via de novo pathway and exported via ABCC1. Further, we found that SPHK1 expression positively correlated with factors related to lymphatic metastasis in BTC. Finally, immunohistochemical examination revealed that gallbladder cancer with lymph node metastasis had significantly higher expression of phospho-SPHK1 than that without. Taken together, our data suggest that S1P generated in BTC contributes to lymphatic metastasis.