Prognostic Role of Preoperative Chemotherapy in Liver-Limited Metastasis from Gastric Cancer.

BACKGROUND: We investigated the prognostic role of preoperative chemotherapy in patients who underwent hepatectomy for liver-limited metastasis (LLM) from gastric cancer (GC). METHODS: A retrospective analysis was conducted for 52 consecutive patients who underwent macroscopically complete (R0 or R1) resection for synchronous or metachronous LLM from GC. RESULTS: Of the 52 patients, 18 (35%) received preoperative chemotherapy (PC group), while 34 (65%) underwent upfront surgery (US group). The PC group had a significantly longer overall survival than the US group (cumulative 5-year OS rate: 47.6% vs. 24.8%, p = 0.041). Multivariate analysis of OS revealed that preoperative chemotherapy was an independent favorable prognostic factor (hazard ratio: 0.445, p = 0.036). Patients showing a partial response to preoperative chemotherapy on RECIST had an improved OS compared with those exhibiting stable or progressive disease after preoperative chemotherapy and with US (p = 0.025), even among those with solitary LLM (p = 0.062) and multiple LLM (p = 0.026). At recurrence after hepatectomy for LLM, the PC group had a significantly higher incidence of solitary tumors than the US group (p = 0.043) and had a higher chance to undergo surgical resection for recurrent sites (p = 0.006). CONCLUSIONS: Preoperative chemotherapy can be recommended for patients with LLM from GC. The evaluation of the efficacy of preoperative chemotherapy offers additional information to determine the surgical indication for LLM.

Profiling of host genetic alterations and intra-tumor microbiomes in colorectal cancer.

Some bacteria are symbiotic in tumor tissues, and metabolites of several bacterial species have been found to cause DNA damage. However, to date, the association between bacteria and host genetic alterations in colorectal cancer (CRC) has not been fully investigated. We evaluated the association between the intra-tumor microbiome and host genetic alterations in 29 Japanese CRC patients. The tumor and non-tumor tissues were extracted from the patients, and 16S rRNA genes were sequenced for each sample. We identified enriched bacteria in tumor and non-tumor tissues. Some bacteria, such as Fusobacterium, which is already known to be enriched in CRC, were found to be enriched in tumor tissues. Interestingly, Bacteroides, which is also known to be enriched in CRC, was enriched in non-tumor tissues. Furthermore, it was shown that certain bacteria that often coexist within tumor tissue were enriched in the presence of a mutated gene or signal pathway with mutated genes in the host cells. Fusobacterium was associated with many mutated genes, as well as cell cycle-related pathways including mutated genes. In addition, the patients with a high abundance of Campylobacter were suggested to be associated with mutational signature 3 indicating failure of double-strand DNA break repairs. These results suggest that CRC development may be partly caused by DNA damage caused by substances released by bacterial infection. Taken together, the identification of distinct gut microbiome patterns and their host specific genetic alterations might facilitate targeted interventions, such as modulation of the microbiome in addition to anticancer agents or immunotherapy.

NQO1 as a Marker of Chemosensitivity and Prognosis for Colorectal Liver Metastasis.

BACKGROUND/AIM: This study aimed to evaluate how NAD(P)H: quinone oxidoreductase-1 (NQO1) affects survival after hepatectomy in patients with colorectal liver metastasis (CRLM). PATIENTS AND METHODS: A retrospective analysis was conducted of 88 consecutive patients who underwent hepatectomy for CRLM. Of the 88 patients, preoperative chemotherapy was administered to 30 patients. Immunohistochemistry of the resected specimens was conducted using monoclonal anti-NQO1 antibody. RESULTS: NQO1-positive expression in tumor cells of CRLM was associated with worse overall survival (p=0.026) and was an independent adverse prognostic factor in multivariate analysis (hazard ratio=5.296, p=0.007). Among 30 patients who received preoperative chemotherapy, patients with loss of NQO1 expression in non-neoplastic epithelial cells of the bile ducts (NQO1 polymorphism: n=19) showed significantly better response to preoperative chemotherapy for CRLM (p=0.004). CONCLUSION: NQO1-positive expression in tumor cells of CRLM may be an adverse prognostic factor after hepatectomy for CRLM.

Outcome of radical surgery for gallbladder carcinoma according to TNM stage: implications for adjuvant therapeutic strategies.

PURPOSE: Outcomes following surgery for advanced gallbladder carcinoma remain unsatisfactory. This study aimed to determine the surgical outcome and effectiveness of adjuvant chemotherapy according to TNM stage in patients with gallbladder carcinoma. METHODS: A total of 200 patients undergoing surgery for gallbladder carcinoma were enrolled. Clinicopathological data were evaluated and surgical outcomes were compared between patients with and without adjuvant chemotherapy according to TNM stage. RESULTS: The 5-year overall survival (OS) after resection for patients with stage I (n = 27), IIA (n = 18), IIB (n = 28), IIIA (n = 25), IIIB (n = 43), IVA (n = 7), and IVB (n = 52) disease was 90.8%, 94.4%, 73.6%, 33.7%, 57.7%, 14.3%, and 11.8%, respectively (p < 0.001). R0 resection was performed in all patients with stage I or II disease, in 89.7% of those with stage III disease, and 69.5% of those with stage IV disease. For patients with stage III disease, adjuvant chemotherapy was associated with improved OS (5-year OS, 60.9% vs. 41.1%; p = 0.028) and was an independent prognostic factor (hazard ratio, 2.045; p = 0.039). For patients with stage IV disease, adjuvant chemotherapy appeared to affect OS (5-year OS, 25.1% vs. 5.3%; p = 0.041); R0 resection (hazard ratio, 1.882; p = 0.040) was the only independent prognostic factor. CONCLUSION: TNM stage clearly predicts survival after resection of gallbladder carcinoma. R0 resection with adjuvant chemotherapy is recommended for long-term survival in the multimodal management of patients with stage III or IV gallbladder carcinoma.

Activin a Receptor Type 2A Mutation Affects the Tumor Biology of Microsatellite Instability-High Gastric Cancer.

BACKGROUND: Activin A receptor type 2A (ACVR2A) is one of the most frequently mutated genes in microsatellite instability-high (MSI-H) gastric cancer. However, the clinical relevance of the ACVR2A mutation in MSI-H gastric cancer patients remains unclear. The aims of this study were to explore the effect of ACVR2A mutation on the tumor behavior and to identify the clinicopathological characteristics of gastric cancer patients with ACVR2A mutations. METHODS: An in vitro study was performed to investigate the biological role of ACVR2A via CRISPR/Cas9-mediated ACVR2A knockout MKN74 human gastric cancer cells. One hundred twenty-four patients with gastric cancer were retrospectively analyzed, and relations between MSI status, ACVR2A mutations, and clinicopathological factors were evaluated. RESULTS: ACVR2A knockout cells showed less aggressive tumor biology than mock-transfected cells, displaying reduced proliferation, migration, and invasion (P < 0.05). MSI mutations were found in 10% (13/124) of gastric cancer patients, and ACVR2A mutations were found in 8.1% (10/124) of patients. All ACVR2A mutations were accompanied by MSI. The 5-year overall survival rates of ACVR2A wild-type patients and ACVR2A-mutated patients were 57% and 90%, respectively (P = 0.048). Multivariate analysis revealed that older age (P = 0.015), distant metastasis (P < 0.001), and ACVR2A wild-type status (P = 0.040) were independent prognostic factors for overall survival. CONCLUSIONS: Our study demonstrated that gastric cancer patients with ACVR2A mutation have a significantly better prognosis than those without. Dysfunction of ACVR2A in MKN74 human gastric cancer cells caused less aggressive tumor biology, indicating the importance of ACVR2A in the progression of MSI-H tumors.

A giant pelvic solitary fibrous tumor with Doege-Potter syndrome successfully treated with transcatheter arterial embolization followed by surgical resection: a case report.

BACKGROUND: Solitary fibrous tumor (SFT), a mesenchymal fibroblastic tumor with a hypervascular nature, rarely develops in the pelvis. Resection of a giant SFT occupying the pelvic cavity poses an increased risk of developing massive hemorrhage during resection, although surgical resection is the most effective treatment method for this tumor to achieve a potential cure. SFT rarely develops with Doege-Potter syndrome, which is known as a paraneoplastic syndrome characterized by non-islet cell tumor hypoglycemia (NICTH) secondary to SFT that secretes insulin-like growth factor-II (IGF-II). We present a case of a giant pelvic SFT with Doege-Potter syndrome, which was successfully treated with transcatheter arterial embolization (TAE) followed by surgical resection. CASE PRESENTATION: A 46-year-old woman presented with a disorder of consciousness due to refractory hypoglycemia. Images of the pelvis showed a giant and heterogeneously hypervascular mass displacing and compressing the rectum. Endocrinological evaluation revealed low serum levels of insulin and C-peptide consistent with NICTH. Angiography identified both the inferior mesenteric artery and the bilateral internal iliac artery as the main feeders of the tumor. To avoid intraoperative massive bleeding, super-selective TAE was performed for the tumor 2 days prior to surgery. Hypoglycemia disappeared after TAE. The tumor was resected completely, with no massive hemorrhage during resection. Histologically, it was diagnosed as IGF-II-secreting SFT. Partial necrosis of the rectum in the specimen was observed due to TAE. The patient was followed up for 2 years and no evidence of disease has been reported. CONCLUSIONS: Preoperative angiography followed by TAE is an exceedingly helpful method to reduce intraoperative hemorrhage when planning to resect SFT occupying the pelvic cavity. Complications related to ischemia should be kept in mind after TAE, which needs to be planned within 1 or 2 days before surgery. TAE for tumors may be an option in addition to medical and surgical treatment for persistent hypoglycemia in Doege-Potter syndrome.

Clinicopathological Characteristics and Surgical Outcomes of Primary Cystic Duct Carcinoma: A Multi-institutional Study.

BACKGROUND: The role of surgery in the management of primary cystic duct carcinoma (CDC) remains unclear especially in advanced disease. This study aimed to evaluate long-term outcomes in patients undergoing surgery for primary CDC. METHODS: From a multi-institutional database, we identified 41 patients who underwent surgery for primary CDC, defined as a part of gallbladder carcinoma with the tumor centre located in the cystic duct. RESULTS: Of the 41 patients, 31 (75.6%) underwent preoperative biliary drainage for jaundice. Twenty-eight (68.3%) patients underwent extensive resection including major hepatectomy (n = 21), pancreaticoduodenectomy (n = 4), or both procedures (n = 3). Thirty-four (82.9%) patients had ≥ pT3 tumor, while 31 (75.6%) patients had involvement of contiguous organs/structures. Nodal and distant metastasis was found in 26 (63.4%) and 7 (17.1%) patients, respectively. Most patients (90.2%) had perineural invasion. Median overall survival was 23.7 months in all 41 patients. Factors independently associated with both overall and disease-specific survival were pN (P = 0.003 and P = 0.007, respectively) and pM (P = 0.003 and P = 0.013, respectively) classification. Median survival was 75.3, 17.7, and 5.2 months for patients with pN0M0 (n = 14), pN1/2pM0 or pN0pM1 (n = 21), and pN1/2pM1 (n = 6) disease, respectively (P < 0.001). CONCLUSIONS: Primary CDC is characterized by locally advanced disease with aggressive histopathological characteristics at surgery, leading to extensive resection during treatment. Surgery provides potential benefits for patients with pN0pM0 disease, whereas pN1/2 and/or pM1 status appear to have strong adverse effects on survival.

Inguinal Herniation After Living Donor Kidney Transplantation: A Case Report.

A 68-year-old male patient received a living donor kidney transplantation 8 years earlier for end-stage kidney disease secondary to IgA nephropathy. His post-transplantation follow-up had been routinely performed with laboratory examinations, ultrasound, and computed tomography (CT). His kidney graft function had been excellent and stable, as shown by a baseline serum creatinine level of 1.0 mg/dL. At referral, regular follow-up ultrasound and CT showed allograft hydroureteronephrosis. He did not have any complaints, but his physical examination revealed right inguinal bulging that was 3.5 × 3.5 cm. Abdominal enhanced CT revealed transplant allograft hydroureteronephrosis due to ipsilateral herniation of ureteroneocystostomy into the right inguinal canal. His serum creatinine level was slightly elevated (1.1 mg/dL). Then, he underwent an open right inguinal hernia repair. Paraperitoneal allograft hydroureteronephrosis and bladder herniation was confirmed at surgery, and hernioplasty with polypropylene mesh reinforcement was successfully performed. The postoperative course was uneventful. He was discharged on the seventh day after surgery. Six weeks after surgery, CT revealed disappearance of allograft hydroureteronephrosis and no sign of inguinal hernia recurrence with the serum creatinine stable at 1.0 mg/dL. Transplant ureteral obstruction due to inguinal hernia is a rare complication after kidney transplantation. However, transplant ureter or bladder herniation should be considered in the differential diagnosis of graft hydroureteronephrosis for preventing allograft loss.

Long-term outcomes of surgical resection for T1b gallbladder cancer: an institutional evaluation.

BACKGROUND: There is no comprehensive agreement concerning the overall performance of radical resection for T1b gallbladder cancer (GBC). This research focused on addressing whether T1b GBC may spread loco-regionally and whether radical resection is necessary. METHODS: A retrospective analysis was conducted of 1032 patients with GBC who underwent surgical resection at our centre and its affiliated institutions between January 1982 and December 2018. A total of 47 patients with T1b GBC, 29 (62%) of whom underwent simple cholecystectomy and 18 (38%) of whom underwent radical resection with regional lymph node dissection, were enrolled in the study. RESULTS: GBC was diagnosed pre-operatively in 16 patients (34%), whereas 31 patients (66%) had incidental GBC. There was no blood venous or perineural invasion in any patient on histology evaluation, except for lymphatic vessel invasion in a single patient. There were no metastases in any analysed lymph nodes. The open surgical approach was more prevalent among the 18 patients who underwent radical resection (open in all 18 patients) than among the 29 patients who underwent simple cholecystectomy (open in 21; laparoscopic in 8) (P = 0.017). The cumulative 10- and 20-year overall survival rates were 65 and 25%, respectively. The outcome following simple cholecystectomy (10-year overall survival rate of 66%) was akin to that following radical resection (64%, P = 0.618). The cumulative 10- and 20-year disease-specific survival rates were 93 and 93%, respectively. The outcome following simple cholecystectomy (10-year disease-specific survival rate of 100%) was equivalent to that following radical resection (that of 86%, P = 0.151). While age (> 70 years, hazard ratio 5.285, P = 0.003) and gender (female, hazard ratio 0.272, P = 0.007) had a strong effect on patient overall survival, surgical procedure (simple cholecystectomy vs. radical resection) and surgical approach (open vs. laparoscopic) did not. CONCLUSIONS: Most T1b GBCs represent local disease. As pre-operative diagnosis, including tumour penetration of T1b GBC, is difficult, the decision of radical resection is justified. Additional radical resection is not required following simple cholecystectomy provided that the penetration depth is restricted towards the muscular layer and that surgical margins are uninvolved.

[Long-Term Survival after Surgery with Postoperative Chemotherapy for Perihilar Cholangiocarcinoma with Residual Invasive Carcinoma at Ductal Resection Margins-A Case Report].

A 64-year-old man with liver dysfunction was given a diagnosis of perihilar cholangiocarcinoma(Bismuth type Ⅳ). The tumor was predominantly right-sided and invaded to the bifurcation of the right and left portal veins. After confirming sufficient liver functional reserve and future liver remnant, the patient underwent extended right hepatectomy, extrahepatic bile duct resection, and portal vein resection and reconstruction. Intraoperative examination of frozen sections revealed the presence of residual invasive carcinoma on both the hepatic and duodenal sides of the ductal resection margins. However, we did not perform pancreaticoduodenectomy or additional resection of the margin-positive proximal bile duct considering the curability and invasiveness of these procedures. He received postoperative chemotherapy with biweekly gemcitabine plus cisplatin for 1 year, followed by gemcitabine monotherapy for 1 year, and S-1 monotherapy has been performed since then. He remains alive and well with no evidence of disease 63 months after surgery.

[A Case of Umbilical Metastasis from Pancreatic Cancer after Surgery].

The patient was a 63-year-old woman with diagnosis of pancreatic cancer. Abdominal CT showed pancreatic head tumor and paraaortic lymph node metastasis. We performed chemotherapy with nab-paclitaxel plus gemcitabine. After 5 courses of chemotherapy, the tumor reduced in size. Pancreaticoduodenectomy followed by adjuvant chemotherapy with S-1 was performed. Fourteen months after surgery, umbilical metastasis(Sister Mary Joseph's nodule: SMJN)was found in the umbilicus near the abdominal incisional hernia. There was no evidence of metastasis except in the umbilicus, we performed the umbilical tumor resection and abdominal incisional hernia repair. Pathological diagnosis was pancreatic cancer metastasis. Although following chemotherapy, multiple skin metastases was found in the lower abdomen 3 months after umbilical resection. We performed skin metastases resection to relieve pain and symptoms of bleeding. But she died 29 months after the initial therapy(7 months after umbilical resection).

Early-stage T1b adenocarcinoma arising in the remnant cystic duct after laparoscopic cholecystectomy: a case report and literature review.

BACKGROUND: The cystic duct has been included in the staging classification scheme for gallbladder cancer since the 2010 publication of the AJCC Cancer Staging Manual (7th edition). To our knowledge, only seven other cases of adenocarcinoma arising in the remnant cystic duct following cholecystectomy have been reported in the English-language literature, and none has been reported as primary early-stage T1b remnant cystic duct cancer (CDC). We report, herein, a case of primary adenocarcinoma arising in the remnant cystic duct in a patient with history of laparoscopic cholecystectomy for gallstone disease. CASE PRESENTATION: An 81-year-old female presented with abdominal pain. Her medical history included a laparoscopic cholecystectomy for cholecystolithiasis two years prior. Jaundice was observed; imaging studies suggested that this was caused by choledocholithiasis. Blood chemistry findings showed severe liver dysfunction. Endoscopic retrograde cholangiography revealed haemobilia from the common bile duct with no evidence of choledocholithiasis. A bile sample showed Papanicolaou class IV cytology. As the extent of tumour spread was undetermined by abdominal ultrasonography and endoscopic ultrasonography, peroral cholangioscopy (POCS) was performed, which revealed tiny papillary lesions within the confluence of cystic duct, and fine granular lesions in the centre of bile ducts, signifying early-stage remnant CDC. Extrahepatic bile duct resection with regional lymphadenectomy was done. Histopathological findings revealed a 42-mm tubular adenocarcinoma originating from the remnant cystic duct with the considerable shallow spread across the extrahepatic bile ducts. It invaded the fibromuscular layer, with no lymphovascular or perineural invasion, no lymph node metastasis (13 nodes examined), and uninvolved surgical resection margin (R0 resection), and was staged as pT1bN0M0, Stage I. CONCLUSIONS: Primary early-stage T1b remnant CDC is an uncommon condition for which early diagnosis is challenging; if intraoperatively recognized, it can complicate surgery. Our experience of this case and an overview of the English literature suggest that POCS is an efficient tool to diagnosis this tumour and assess its spread along the extrahepatic bile ducts.

Lymphatic spread of T2 gallbladder carcinoma: Regional lymphadenectomy is required independent of tumor location.

BACKGROUND: This study aimed to investigate the incidence and distribution of regional lymph node metastasis according to tumor location, and to clarify whether tumor location could determine the extent of regional lymphadenectomy in patients with pathological T2 (pT2) gallbladder carcinoma. METHODS: In total, 81 patients with pT2 gallbladder carcinoma (25 with pT2a tumors and 56 with pT2b tumors) who underwent radical resection were enrolled. Tumor location was determined histologically in each gallbladder specimen. RESULTS: Survival after resection was significantly worse in patients with pT2b tumors than those with pT2a tumors (5-year survival, 72% vs. 96%; p = 0.027). Tumor location was an independent prognostic factor on multivariate analysis (hazard ratio, 14.162; p = 0.018). The incidence of regional lymph node metastasis was significantly higher in patients with pT2b tumors than in those with pT2a tumors (46% vs. 20%; p = 0.028). However, the number of positive nodes was similar between the two groups (median, 2 vs. 2; p = 0.910). For node-positive patients with pT2b tumors, metastasis was found in every regional node group (12%-63%), whereas even for node-positive patients with pT2a tumors, metastasis was observed in regional node groups outside the hepatoduodenal ligament. CONCLUSIONS: Tumor location in patients with pT2 gallbladder carcinoma can predict the presence or absence of regional lymph node metastasis but not the number and anatomical distribution of positive regional lymph nodes. The extent of regional lymphadenectomy should not be changed even in patients with pT2a tumors, provided that they are fit enough for surgery.

[Surgical Resection after Transarterial Chemoembolization for Hepatocellular Carcinoma with Bile Duct Tumor Thrombus-Report of a Long-Term Survivor].

A 78-year-old woman with jaundice was referred to our hospital. On admission, serological testing for viral hepatitis was negative and serum levels of AFP and PIVKA-Ⅱ were elevated(925 ng/mL and 6,820 mAU/mL, respectively). Computed tomography revealed a main tumor measuring 3 cm in size at segment 1 of the liver and bile duct tumor thrombus extending to the right hepatic duct. A diagnosis of hepatocellular carcinoma with a bile duct tumor thrombus was made. After endoscopic biliary drainage for obstructive jaundice and transarterial chemoembolization for the lesions, she underwent left hepatectomy, resection of the caudate lobe, extrahepatic bile duct resection, and cholecystectomy. The hepatic side of the extrahepatic bile duct was transected at the confluence of the right anterior and posterior ducts because invasion of the tumor thrombus to the right hepatic duct was suspected on cholangioscopy. Histological examination revealed the tumor to be a moderately differentiated hepatocellular carcinoma with bile duct tumor thrombus. Surgical margins were negative, and vascular invasion was not found. She remains alive and well with no evidence of disease 64 months after hepatectomy.

[A Case of Peritoneal Recurrence of Invasive Ductal Carcinoma Derived from Intraductal Papillary Mucinous Neoplasm after Surgery Treated with Palliative Radiation Therapy and Chemotherapy].

An 82-year-old man with a diagnosis ofintraductal papillary mucinous carcinoma(IPMC)underwent pancreaticoduodenectomy followed by adjuvant chemotherapy with S-1. Six months after surgery, he had upper abdominal pain, and CT demonstrated a recurrent intraabdominal tumor located at the surgical incision scar. It was diagnosed as a solitary peritoneal recurrence, and palliative radiation therapy at a dose of 30 Gy was performed for the relief of abdominal pain after administration ofoxycodone. He was free ofpain without pharmacological therapy and received subsequent chemotherapy with nabpaclitaxel plus gemcitabine(GnP). He remains free ofpain and alive without progression ofthe disease 24 months after recurrence. Hypofractionated-accelerated radiotherapy is feasible and results in pain relief for local recurrence of IPMC.

[A Case of Peritoneal Metastases after Radiofrequency Ablation for Liver Metastasis from a Pancreatic Neuroendocrine Tumor].

A 77-year-old woman presented with peritoneal metastases from a pancreatic neuroendocrine tumor(p-NET). At the age of 56 years, she underwent distal pancreatectomy for p-NET, which was pathologically diagnosed as G2. She underwent right hemihepatectomy for liver metastasis(S6)from the p-NET 10 years post-pancreatectomy. Eight years post-hepatectomy, radiofrequency ablation(RFA)was attempted for liver metastasis(S4)from the p-NET. However, RFA was not completed because of hematoma development along the needle tract of RFA. She underwent partial hepatectomy for this lesion 6 months post-RFA. Two years post-RFA, localized peritoneal metastases on the right diaphragm were detected. She underwent en bloc tumor resection with partial resection of the diaphragm. She remains alive and well with no evidence of disease 2 years post-resection of the peritoneal metastases from the p-NET.

Different Roles of Sphingosine Kinase 1 and 2 in Pancreatic Cancer Progression.

BACKGROUND: Pancreatic cancer is a disease with poor prognosis, and development of new treatments is necessary. Sphingosine-1-phosphate (S1P), a bioactive lipid mediator produced by sphingosine kinases (SphK1 and SphK2), plays a critical role in progression of many types of cancer. However, little is known about the role of sphingosine kinases in pancreatic cancer. This study investigated the roles of sphingosine kinases in pancreatic cancer progression. MATERIALS AND METHODS: S1P levels in pancreatic cancer and noncancerous pancreatic tissue were measured in 10 patients. We generated PAN02 murine pancreatic cancer cell lines with a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system genes 9 (Cas9)-mediated deletion of SphK1 or SphK2 and assessed cell growth and migration. In an animal model, we assessed the survival of mice injected with PAN02 cells intraperitoneally. RESULTS: S1P levels in the pancreatic cancer tissue were significantly higher than those in noncancerous tissue. SphK1 knockout (KO) cells showed greater proliferation and migration than wild type (WT) cells, and SphK2 KO cells showed less proliferation and migration than WT cells. Animal experiments showed that the survival of mice injected with SphK1 KO cells was significantly shorter than those injected with WT cells, and the survival of mice injected with SphK2 KO cells was longer than those injected with WT cells. Surprisingly, cytotoxic assay using gemcitabine showed that SphK1 KO cells survived less than WT cells, and SphK2 KO cells survived more than WT cells. CONCLUSIONS: S1P produced by SphK1 and SphK2 may have different functions in pancreatic cancer cells. Targeting both SphK1 and SphK2 may be a potential strategy for pancreatic cancer treatment.