Multiple metastases of human epidermal growth factor receptor 2­positive, hormone receptor­positive, pT1a pN0 breast cancer within 1 year after surgery: A case report.

Adjuvant chemotherapy is usually not considered for pT1a pN0 human epidermal growth factor receptor 2 (HER2)-positive breast cancer due to its low recurrence rate. The present report describes a case of pT1a hormone receptor-positive HER2-positive breast cancer with multiple recurrences in the axillary lymph nodes and liver within 1 year after radical surgery. A 58-year-old woman underwent left total mastectomy and sentinel lymph node biopsy for left breast cancer with pathological stage IA (pT1a pN0). The subtype corresponded to luminal B-like breast cancer with a nuclear grade of 3 and a Ki-67 labeling index of 37%. An aromatase inhibitor (letrozole) was planned to be administered for 5 years after surgery, but the patient was diagnosed with multiple liver and axillary lymph node metastases 11 months after surgery. After 1 year of chemotherapy (paclitaxel) in combination with anti-HER2 therapy (pertuzumab and trastuzumab), liver metastases resolved. A complete response of the liver lesion has been maintained 4 years after the anti-HER2 therapy initiation. The present case exhibited two poor prognostic factors: High Ki-67 labeling index and nuclear grade 3. Based on the 'Predict' tool, the present case would be expected to have a cancer-related mortality rate of 6% 10 years after surgery with adjuvant endocrine therapy. Although this value may be controversial for postoperative anti-HER2 therapy, the present case should not be considered to be a low-risk case. When the identification of high-risk pT1a pN0 HER2-positive breast cancer is possible, postoperative anti-HER2 therapy plus chemotherapy would be effective in decreasing the rate of recurrence.

Differential squamous cell fates elicited by NRF2 gain of function versus KEAP1 loss of function.

Clinical evidence has revealed that high-level activation of NRF2 caused by somatic mutations in NRF2 (NFE2L2) is frequently detected in esophageal squamous cell carcinoma (ESCC), whereas that caused by somatic mutations in KEAP1, a negative regulator of NRF2, is not. Here, we aspire to generate a mouse model of NRF2-activated ESCC using the cancer-derived NRF2L30F mutation and cancer driver mutant TRP53R172H. Concomitant expression of NRF2L30F and TRP53R172H results in formation of NRF2-activated ESCC-like lesions. In contrast, while squamous-cell-specific deletion of KEAP1 induces similar NRF2 hyperactivation, the loss of KEAP1 combined with expression of TRP53R172H does not elicit the formation of ESCC-like lesions. Instead, KEAP1-deleted cells disappear from the esophageal epithelium over time. These findings demonstrate that, while cellular NRF2 levels are similarly induced, NRF2 gain of function and KEAP1 loss of function elicits distinct fates of squamous cells. The NRF2L30F mutant mouse model developed here will be instrumental in elucidating the mechanistic basis leading to NRF2-activated ESCC.

Cross-Limb Vascular Shunting for Traumatic Popliteal Artery Injury.

BACKGROUND: Popliteal artery injury (PAI) is a challenging trauma that requires prompt and accurate treatment since the probability of lower-limb amputation increases with the ischemic time. Intravascular shunting and cross-limb vascular shunting (CLS) are used as temporary vascular shunting (TVS) methods to shorten the ischemic time for limb vascular injury. CLS involves sending blood from an artery in a healthy body part to a peripheral vessel in an injured part to immediately resume blood flow to the injured limb. For closed injuries including PAI, CLS may be performed without exploring and identifying the arterial stumps and it enables early reperfusion to the ischemic limb. We report the case series of traumatic PAI treated using CLS and verify the usefulness of CLS. METHODS: All patients with traumatic PAI treated with CLS at our institution between August 2013 and December 2021 were included. Demographic and clinical patient characteristics were extracted from the medical records. Comorbid injuries, severity of acute limb ischemia based on the Rutherford grading scale, time from injury to reperfusion by CLS, time from injury to completion of artery, and the use of fasciotomy were investigated. As outcomes, we investigated the presence or absence of lower extremity amputation during the course of treatment. RESULTS: We used CLS as treatment for 5 cases with traumatic PAI. Based on the Rutherford grading scale for acute limb ischemia, there were one limb with grade 2B and 4 with grade 3. Amputation of the lower extremities was avoided except for 1 extremity in which arterial reconstruction was not achieved due to unexplained cardiac arrest during surgery. CONCLUSIONS: CLS enables early reperfusion of the injured limb and is effective as a TVS method for traumatic PAI with severe ischemia or soft tissue damage.

A NRF2-induced secretory phenotype activates immune surveillance to remove irreparably damaged cells.

While it is well established that the KEAP1-NRF2 pathway regulates the main inducible cellular response to oxidative stress, this cytoprotective function of NRF2 could become deleterious to the host if it confers survival onto irreparably damaged cells. In this regard, we have found that in diseased states, NRF2 promotes the transcriptional activation of a specific subset of the senescence-associated secretory phenotype (SASP) gene program, which we have named the NRF2-induced secretory phenotype (NISP). In two models of hepatic disease using Pten::Keap1 and Keap1::Atg7 double knockout mice, we found that the NISP functions in the liver to recruit CCR2 expressing monocytes, which function as immune system effector cells to directly remove the damaged cells. Through activation of this immune surveillance pathway, in non-transformed cells, NRF2 functions as a tumour suppressor to mitigate the long-term survival of damaged cells which otherwise would be detrimental for host survival. This pathway represents the final stage of the oxidative stress response, as it allows cells to be safely removed if the macromolecular damage caused by the original stressor is so extensive that it is beyond the repair capacity of the cell.

Malignant Glaucoma After Immediate Primary Phacoemulsification for Acute Primary Angle Closure: A Case Report.

Malignant glaucoma is characterized by ciliary block or aqueous misdirection, shallowing of the anterior chamber with elevated intraocular pressure (IOP), resistance to treatment, and rapid progression to blindness. However, the exact pathogenic mechanism is yet to be established. Here, we report a case of malignant glaucoma caused by immediate primary phacoemulsification for acute primary angle closure (APAC). A 90-year-old woman, who had experienced right eye pain and blurred vision one day prior, had a cataract in the same eye without phacodonesis. The right eye IOP was 39 mmHg, preoperative anterior chamber depth was 1.00 mm, and the axial length was 22.31 mm. We diagnosed APAC in the right eye and performed phacoemulsification. On postoperative day one, the IOP decreased to the normal range (15 mmHg), the anterior chamber deepened, and the angle became open. However, one week after phacoemulsification, the anterior chamber and angle became shallower and closer again. We diagnosed the patient with malignant glaucoma, performed hyaloid-zonulo-iridectomy, and administered 1% atropine eye drops postoperatively. As a result, the IOP was limited to a 10 mmHg range with an open angle and deep anterior chamber. Malignant glaucoma can be caused by immediate primary phacoemulsification for APAC.

A Point Mutation at C151 of Keap1 of Mice Abrogates NRF2 Signaling, Cytoprotection in Vitro, and Hepatoprotection in Vivo by Bardoxolone Methyl (CDDO-Me).

Bardoxolone methyl (CDDO-Me) is an oleanane triterpenoid in late-stage clinical development for the treatment of patients with diabetic kidney disease. Preclinical studies in rodents demonstrate the efficacy of triterpenoids against carcinogenesis and other diseases, including renal ischemia-reperfusion injury, hyperoxia-induced acute lung injury, and immune hepatitis. Genetic disruption of Nrf2 abrogates protection by triterpenoids, suggesting that induction of the NRF2 pathway may drive this protection. Herein, we examined the effect of a point mutation (C151S) in KEAP1, a repressor of NRF2 signaling, at cysteine 151 in mouse embryo fibroblasts and mouse liver. Induction of target gene transcripts and enzyme activity by CDDO-Me was lost in C151S mutant fibroblasts compared with wild-type. Protection against menadione toxicity was also nullified in the mutant fibroblasts. In mouse liver, CDDO-Me evoked the nuclear translocation of NRF2, followed by increased transcript and activity levels of a prototypic target gene, Nqo1, in wild-type, but not C151S mutant, mice. To test the role of KEAP1 Cys151 in governing the broader pharmacodynamic action of CDDO-Me, wild-type and C151S mutant mice were challenged with concanavalin A to induce immune hepatitis. Strong protection was seen in wild-type but not C151S mutant mice. RNA-seq analysis of mouse liver from wild-type, C151S mutant, and Nrf2-knockout mice revealed a vigorous response of the NRF2 transcriptome in wild-type, but in neither C151S mutant nor Nrf2-knockout, mice. Activation of "off-target" pathways by CDDO were not observed. These data highlight the singular importance of the KEAP1 cysteine 151 sensor for activation of NRF2 signaling by CDDO-Me. SIGNIFICANCE STATEMENT: KEAP1 serves as a key sensor for induction of the cytoprotective signaling pathway driven by the transcription factor NRF2. Mutation of a single cysteine (C151) in KEAP1 abrogates the induction of NRF2 signaling and its downstream cytoprotective actions in vitro and in vivo by bardoxolone methyl (CDDO-Me), a drug in late-stage clinical development. Further, at these bioeffective concentrations/doses, activation of "off-target" pathways by CDDO-Me are not observed, highlighting the singular importance of NRF2 in its mode of action.

Management of bone loss in acute severe open tibial fractures: a retrospective study of twenty nine cases-a treatment strategy with bone length preservation.

PURPOSE: The present study investigated the outcomes of bone loss associated with acute open tibial fractures classified as Gustilo-Anderson classification grade III B (GIIIB) using a bone length preservation strategy. METHODS: Among acute GIIIB open tibial fractures, 29 limbs of 29 patients requiring bone loss treatment were included. The reconstruction methods for bone loss were selected among the Masquelet technique (MT), bone transport (BT), acute shortening followed by gradual lengthening (ASGL), and free vascularized fibula graft (FVFG). Primary outcome measures were the rate of bone union and time to bone union. RESULTS: The median radiographic apparent bone gap (RABG) was 46.75 mm. Bone loss was treated with ASGL only in two patients in whom it was not possible to cover large soft tissue defects by a single free latissimus dorsi (LD) myocutaneous flap (with the serratus anterior (SA) muscle). The other 27 patients underwent soft tissue reconstruction and bone loss treatment with the preservation of bone length, including the MT for 23, BT for six, and FVFG for one. The bone union rate was 75.9%, and the median time to bone union was six months. Salvage surgeries were performed on all seven patients with nonunion; all of whom eventually achieved bony union. CONCLUSION: Bone loss associated with acute GIIIB open tibial fractures were treated with "bone length preservation" if the size of the soft tissue defect was less than the size that was covered by a single LD myocutaneous flap (with the SA muscle).

Molecular Basis of the KEAP1-NRF2 Signaling Pathway.

Transcription factor NRF2 (NF-E2-related factor 2) is a master regulator of cellular responses against environmental stresses. NRF2 induces expression of detoxification and antioxidant enzymes and suppresses inductions of pro-inflammatory cytokine genes. KEAP1 (Kelch-like ECH-associated protein 1) is an adaptor subunit of CULLIN 3 (CUL3)-based E3 ubiquitin ligase. KEAP1 regulates the activity of NRF2 and acts as a sensor for oxidative and electrophilic stresses. NRF2 has been found to be activated in many types of cancers with poor prognosis. Therapeutic strategies to control NRF2-overeactivated cancers have been considered not only by targeting cancer cells with NRF2 inhibitors or NRF2 synthetic lethal chemicals, but also by targeting host defense with NRF2 inducers. Understanding precise molecular mechanisms how the KEAP1-NRF2 system senses and regulates the cellular response is critical to overcome intractable NRF2-activated cancers.

Clinical significance of postoperative subcutaneous emphysema after video-assisted thoracoscopic surgery for esophageal cancer.

BACKGROUND: Postoperative subcutaneous emphysema (SE) is a possible complication of thoracoscopic or laparoscopic surgery. This study investigated the risk factors and clinical significance of SE after video-assisted thoracoscopic surgery for esophageal cancer (VATS-e). METHODS: This study included 135 patients who underwent VATS-e with artificial CO2 pneumothorax. Based on the X-ray images on the first postoperative day, patients were divided into two groups: N/L group (no SE or SE localized at the thoracic area, n = 65) and SE group (SE extended to the cervical area, n = 70). We compared clinicopathological features, surgical findings, and short-term outcomes between the two groups. RESULTS: In SE group, there were more patients who received neoadjuvant chemotherapy compared to N/L group. SE group had significantly lower preoperative body mass index. SE group had more frequently two-lung ventilation than N/L group. Multivariate analysis demonstrated that low BMI, NAC, and two-lung ventilation were independent risk factors for SE extended to the cervical area. Although pulmonary complication was relatively frequent in SE group, there were no significant differences in surgical outcomes between two groups, and all patients had SE disappeared within 21 days without serious complications. CONCLUSIONS: Despite extension to the cervical area, SE had a modest impact on the short-term result of VATS-e with artificial CO2 pneumothorax.

Epiretinal Membrane Surgery for a Patient with Dyskinesia Related to Parkinson's Disease Using Intravenous Dexmedetomidine Administration.

General anesthesia is usually selected when patients cannot remain still during surgery with local anesthesia. However, damage to the lungs from positive pressure ventilation under general anesthesia is a major concern in patients with Parkinson's disease. We report a case in which dyskinesia related to Parkinson's disease was attenuated by intravenous dexmedetomidine (DEX) administration, following which epiretinal membrane (ERM) and inner limited membrane peeling could be smoothly performed. A 68-year-old woman with systemic dyskinesia related to Parkinson's disease underwent cataract surgery for her right eye with local anesthesia (topical anesthesia with 4% lidocaine and sub-Tenon's anesthesia with 2% lidocaine and 30% nitrous oxide inhalation). During the surgery, continuous involuntary facial movement related to Parkinson's disease remained uncontrollable. One week later, she underwent cataract surgery and pars plana vitrectomy for the ERM of her left eye. In addition to local anesthesia (topical anesthesia with 4% lidocaine and retrobulbar anesthesia with 2% lidocaine and 30% nitrous oxide inhalation), the patient received intravenous DEX, which halted movement from the beginning of surgery until the end. Therefore, ERM surgery was performed without the influence of dyskinesia. This case highlights that intravenous DEX administration can inhibit dyskinesia related to Parkinson's disease during ERM surgery, which is among the most delicate microscopic procedures performed in ophthalmological settings. Additional studies are required to examine the actual effectiveness of DEX administration in patients with Parkinson's disease-related dyskinesia undergoing ophthalmological procedures.

Tolerability of neoadjuvant chemotherapy for esophageal cancer in elderly patients over 76 years of age.

Although the Japan Clinical Oncology Group trial demonstrated that neoadjuvant chemotherapy (NAC) with 5-fluorouracil plus cis-diamminedichloroplatinum had significant survival benefits, it excluded elderly patients aged ≥ 76 years. Therefore, our study aimed to evaluate the tolerability of NAC in elderly patients with esophageal cancer. Classified 174 patients with clinical stage II/III esophageal cancer who underwent esophagectomy from 2010 to 2020 into the E (aged ≥ 76 years; 55 patients) and Y (aged < 76; 119 patients) groups, and retrospectively investigated for clinicopathological findings, tolerability of NAC, relative dose intensity (RDI) and short- and long-term result. Patients who received NAC were fewer in the E group than in the Y group (51% vs 77%, p = 0.001). The E group had relatively lower completion rate of NAC (71% vs 85%, p = 0.116) and significantly lower mean RDI of 5-fluorouracil and cis-diamminedichloroplatinum than the Y group (73% vs 89%, p < 0.001). However, histological and radiological were comparable between both groups. Severe adverse events (grade ≥ 3) were relatively frequent (E, 42.9%; Y, 27.5%, p = 0.091), especially, neutropenia was significantly more frequent in the E group (25.0% vs 7.7%, p = 0.022). There were no differences in the incidence of postoperative complications between with and without NAC in both E and Y groups. Elderly patients with esophageal cancer might be more susceptible to toxicity of NAC. Hence, adequate case selection and careful of dose reduction are needed for elderly with esophageal cancer.

Three-dimensional heads-up surgery in ab-interno trabeculotomy: Image processing-assisted trabeculotomy.

PURPOSE: We compared the visibility and surgeon posture between image-processing-assisted trabeculotomy (IP-LOT) using the NGENUITY® 3D visual system and conventional microsurgery (microscope-assisted trabeculotomy; MS-LOT). METHODS: IP-LOT was performed for five pig eyes. The visibility of the trabecular mesh work was evaluated on images of the trabecular mesh work and the posterior surface of the cornea (Cor) obtained under three different conditions. Images were then analyzed using ImageJ® to measure differences in luminance between the trabecular mesh work and Cor. IP-LOT was also performed for eleven human eyes, and the data were analyzed using the same approach as that used for the pig eyes. The length from the surgeon's abdomen to the operative eye (working distance) during MS-LOT and IP-LOT was measured for 12 different surgeons and compared to evaluate surgeon posture. RESULTS: Image processing significantly increased the difference in luminance between the trabecular mesh work and Cor in both pig and human eyes (p < 0.05). Moreover, the working distance in IP-LOT was significantly shorter than that in MS-LOT (p < 0.05). CONCLUSION: Our findings suggest that the NGENUITY® 3D visual system provides better trabecular mesh work visibility than a normal microscope in conventional surgical methods, and it allows surgeons to operate without moving far from the operative eye.

Acute Onset of Dense Vitreous Hemorrhage Associated with Retinal Arterial Macroaneurysm on the Optic Disc.

We present a rare case of acute onset of dense vitreous hemorrhage (VH) associated with ruptured retinal arterial macroaneurysm (RAM) on the optic disc. A 63-year-old Japanese man had undergone phacoemulsification combined with pars plana vitrectomy (PPV) including internal limiting membrane peeling in the right eye for a macular hole approximately 1 year before presentation. His decimal best-corrected visual acuity (BCVA) in the right eye was stable at 0.8 with no recurrence of macular hole. He visited our hospital emergently prior to his regular postoperative visit for a sudden decrease in visual acuity in the right eye. Clinical examinations and imaging tests revealed dense VH in the right eye, and we could not observe the fundus. B-mode ultrasonography of the right eye showed dense VH without retinal detachment and a bulge on the optic disc. His BCVA decreased to hand movement in the right eye. He had no medical history of hypertension, diabetes, dyslipidemia, antithrombotics, or ocular inflammation in both eyes. Accordingly, we performed PPV on the right eye. During vitrectomy, we found a RAM on the optic disc with retinal hemorrhage on the nasal side. We carefully reviewed the preoperative color fundus photographs and noticed that RAM was not present on the optic disc at the time of his visit 4 months earlier. After surgery, his BCVA improved to 1.2, the color of the RAM on the optic disc changed to grayish yellow, and optical coherence tomography images showed a shrunken RAM. RAM on the optic disc could cause VH early after its onset.

Prognosis of anal canal adenocarcinoma versus lower rectal adenocarcinoma in Japan: a propensity score matching study.

PURPOSE: Anal canal adenocarcinoma (AC) is rare and its surgical outcomes and prognostic factors (PFs) are not well understood. The aim of this retrospective study was to identify the characteristics and PFs of AC, using population-based data in Japan. METHODS: Patients with AC (n = 390) or lower rectal adenocarcinoma (LR) (n = 12,477) diagnosed between1991 and 2006 were enrolled in this study. We compared the clinical- and patient-related factors of the two diseases and then examined propensity score matching, overall survival (OS), and PFs. RESULTS: AC tended to develop more often in women and in patients of advanced age. Macroscopically, AC was of an unclassified type and microscopically, it was of high-grade histological types such as mucinous adenocarcinoma, poorly differentiated adenocarcinoma (por), or signet-ring cell carcinoma (sig), with a high frequency of inguinal node metastasis (P < 0.05). The 5 year OS rates were 56.9% for AC and 67.9% for LR (P = 0.002). The PFs of AC were a high-grade histological type (por/sig), T, N, and M. CONCLUSIONS: AC has a significantly worse prognosis than LR. Moreover, the AC lymph node metastatic sites for AC, especially the inguinal nodes, are different from those for LR.

Co-expression of mesothelin and CA125/MUC16 is a prognostic factor for breast cancer, especially in luminal-type breast cancer patients.

The expression of mesothelin correlates with a poor prognosis in patients with breast cancer. Since mesothelin plays a role in cancer metastasis in association with CA125, we herein examined the expression of mesothelin and CA125, and the clinicopathological meaning and prognosis of the co-expression of mesothelin and CA125 in breast cancer. Our results showed that among 478 patients, mesothelin and CA125 were co-expressed in 48 (10 %), mesothelin only in 75 (16 %), CA125 only in 217 (45 %), and neither in 234 (49 %). A high correlation was observed between the expression of mesothelin and CA125 (P =0.0004). The co-expression of mesothelin and CA125 correlated with poor patient relapse-free survival (RFS) (P = 0.0001) and was identified as an independent predictor of RFS by Cox's multivariate analysis. In conclusion, this is the first to report the prognostic significance of the co-expression of mesothelin and CA125 in breast cancer. The co-expression of mesothelin and CA125 may be clinically useful for prognostication after surgical therapy in patients with breast cancer.

Efficacy of treatment with corticosteroids for fibrotic hypersensitivity pneumonitis: a propensity score-matched cohort analysis.

BACKGROUND: Fibrotic hypersensitivity pneumonitis (HP) is a chronic interstitial lung disease caused by allergic responses to repeated exposures to a causative antigen. Therapeutic evidence of the use of corticosteroids to treat fibrotic HP remains lacking, although corticosteroids are recognized as a major treatment option. The purpose of this study was to evaluate the efficacy of corticosteroid treatment in patients with fibrotic HP in a propensity score-matched cohort. METHODS: A retrospective review of the medical records from 2005 to 2019 in a single center was conducted, and 144 patients with fibrotic HP were identified. Semiquantitative scores for lung abnormalities on HRCT were evaluated. Patients who received (PDN group) and did not receive (non-PDN group) corticosteroid treatment were matched using a propensity score method. Survival rates, serial changes in pulmonary function and annual changes in HRCT scores were compared in the matched cohort. RESULTS: In the matched analysis, 30 individuals in the PDN group were matched with 30 individuals in the non-PDN group, the majority of whom had ILD without extensive fibrosis. The survival rate was significantly better in the PDN group (P = 0.032 for the stratified Cox proportional hazards model; HR, 0.250). The absolute changes in FVC at 6, 12, and 24 months from baseline were significantly better in the PDN group. Fewer patients in the PDN group experienced annual deterioration, as reflected in the HRCT score, due to ground-glass attenuation, consolidation, reticulation, traction bronchiectasis and honeycombing. CONCLUSION: We demonstrated that corticosteroids improved survival and slowed fibrotic progression in a matched cohort, the majority of whom had ILD without extensive fibrosis. Fibrotic HP with less severe fibrosis may benefit from corticosteroid treatment. We propose that the early initiation of corticosteroids should be considered for fibrotic HP when worsening fibrosis is observed.

Incidence and changing patterns of uveitis in Central Tokyo.

PURPOSE: The patterns of uveitis in Tokyo have recently changed due to advances in examination tools. We aimed to investigate the changes in the patterns of uveitis between 2004-2015 and 2016-2018. METHODS: We retrospectively reviewed the data of 732 patients who visited the Uveitis Clinic at the University of Tokyo Hospital between January 2016 and December 2018. Background characteristics, laboratory results, and imaging findings were analysed. We compared the incidences of uveitis in 2016-2018 and 2004-2015 to identify changes in the patterns. RESULTS: The most frequent diagnoses were sarcoidosis (8.9%), herpetic iridocyclitis (6.7%), intraocular lymphoma (5.5%), Vogt-Koyanagi-Harada disease (4.8%), unclassified acute anterior uveitis (4.6%), Behçet's disease (4.5%), bacterial endophthalmitis (2.9%), and Posner-Schlossman syndrome (2.6%). Suspected sarcoidosis (20.9%) was the most common cause of unclassified uveitis. The incidence of intraocular lymphoma was significantly higher in 2016-2018 than in 2004-2015. Between 2004 and 2018, herpetic iridocyclitis, bacterial endophthalmitis, and juvenile chronic iridocyclitis exhibited an increasing trend, and the incidences of Posner-Schlossman syndrome, unclassified acute anterior uveitis, Behçet's disease, and Vogt-Koyanagi-Harada disease exhibited a decreasing trend. CONCLUSION: The changing patterns of uveitis were characterised by increases in the incidence of intraocular lymphoma. This may be attributed to recent advances in examination tools, the changes in the referred patient population, and the aging Japanese population.

Different role of MSLN and CA125 co-expression as a prognostic predictor between perihilar and distal bile duct carcinoma.

Recent studies have suggested that the interaction of mesothelin (MSLN) and cancer antigen 125 (CA125) enhances tumor metastases. The aim of the present study was to clarify the impact of MSLN and CA125 co-expression on the prognosis of patients with extrahepatic bile duct carcinoma (BDC). Tissue samples from patients who underwent surgical resection between 2007 and 2015 for perihilar or distal BDC were immunohistochemically examined. The expression levels of MSLN and CA125 in tumor cells were analyzed. The expression in <50% and ≥50% of the total tumor cells were defined as low- and high-level expression, respectively. Tissue samples were obtained from 31 patients with perihilar BDC and 43 patients with distal BDC. Lymph node metastases were associated with MSLN and CA125 co-expression in patients with perihilar BDC (P=0.002), while there was no association between lymph node metastasis and co-expression in patients with distal BDC (P=0.362). MSLN and CA125 co-expression was associated with a worse overall survival rate in patients with perihilar BDC (5-year overall survival rate, co-expression positive vs. negative, 24 vs. 63%; P=0.038). To the best of our knowledge, the present study is the first to report an association between co-expression of MSLN and CA125 with a poor prognosis in patients with perihilar BDC. The current findings suggested that the significance of co-expression differed according to the BDC location.