Tumor thickness as a novel risk factor for lymph node metastasis by superficial squamous cell carcinoma of head and neck.

Narrow-band imaging combined with magnified endoscopy has enabled the detection of superficial squamous cell carcinoma of the head and neck (SSCCHN) that has been resected with minimally invasive treatment, preserving vocalization and swallowing functions. However, risk factors of lymph node metastasis (LNM) must be identified, as some patients with LNM have a poor prognosis. From an initial 599 patients with 700 lesions who underwent trans-oral surgery in 27 Japanese hospitals (a nationwide registration survey), we enrolled 541 patients with 633 SSCCHNs, as indicated by central pathological diagnoses. All pathological specimens for each patient were examined using 20 pathological factors that are thought to affect the LNM of SSCCHN. In all, 24 (4.4%) of the 568 SSCCHNs exhibited LNM, and all 24 had at least one solitary nest of epithelial neoplastic cells present in the stroma, clearly separated from the intraepithelial carcinoma. Multivariate analysis also showed that tumor thickness (p = 0.0132, RR: 7.85, 95% confidence interval [CI]: 1.54-40.02), and an INFc pattern classified as infiltrating growth (INF) with unclear boundaries between tumor and non-tumor tissues (p = 0.0003, RR: 14.47, 3.46-60.46), and tumor budding (p = 0.0019, RR: 4.35, CI: 1.72-11.01) were significantly associated with LNM. Solitary nests may be indicative of LNM. In addition, tumor thickness was revealed to be a risk factor for LNM in SSCCHNs using pT factors that do not include an invasion depth element because of the anatomical absence of the muscularis mucosae.

Optimizing Organ Preservation Strategies through Chemotherapy-Based Selection in Esophageal Squamous Cell Carcinoma: Results from the CROC Multi-Institutional Phase II Clinical Trial.

PURPOSE: This study aimed to assess the viability of definitive chemoradiotherapy (dCRT) as an organ-preservation strategy for remarkable responders who were downstaged to stage IA after receiving induction chemotherapy for resectable esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: Chemotherapy-naïve patients with resectable ESCC (stage IB-III, UICC, International Cancer Control 7th edition) were eligible for the study. All patients received three cycles of DCF therapy (docetaxel 75 mg/m2 on day 1, cisplatin 75 mg/m2 on day 1, and 5-fluorouracil [5-FU] 750 mg/m2 on days 1-5, repeated every three weeks). A remarkable response was defined as a reduction of the tumor to T1, metastatic lymph nodes smaller than 1 cm on the short axis, and downstaging to stage IA after three cycles of DCF therapy. Remarkable responders then underwent dCRT, which included two courses of cisplatin 75 mg/m2 and 5-FU 1000 mg/m2 on days 1-4, repeated every four weeks, along with 50.4 Gy of concurrent radiotherapy. The primary endpoint was 1-year progression-free survival (PFS) in remarkable responders following DCF therapy and subsequent dCRT. Secondary endpoints included 3-year overall survival (OS) and esophagectomy-free survival (EFS). RESULTS: Of the 92 patients registered, 90 were analyzed. A remarkable response to three courses of DCF therapy was observed in 58.4% of patients. Among these responders, 89.8% achieved a complete response after dCRT. During the median follow-up period of 33 months (range: 1-85 months), the 1-year PFS was 89.8% (95% confidence interval = 77.2%-95.6%, primary endpoint), and the 3-year OS was 83.7%. The 3-year OS and EFS rates in the analysis group were 74.1% and 45.3%, respectively. An 18F-fluorodeoxyglucose-positron emission tomography response after two courses of DCF therapy was significantly associated with OS (p = 0.0049). CONCLUSIONS: In patients with resectable ESCC, dCRT for remarkable responders downstaging to stage IA after induction chemotherapy with three courses of DCF therapy is a feasible treatment option and provides an optimizing organ-preservation strategy of chemotherapy-based selection.

Remarkable response to capmatinib in a patient with intrahepatic cholangiocarcinoma harboring TFG-MET fusion.

Dysregulation of mesenchymal-epithelial transition factor (MET) gene due to amplification, mutation, and fusion has been reported in various types of human cancers. Recently, the efficacy of small-molecule tyrosine kinase inhibitors (TKIs) targeting MET has been demonstrated in a wide range of MET-dysregulated tumors. The majority of biliary tract cancers including intrahepatic cholangiocarcinoma (iCCA) are diagnosed at an advanced stage, and the utility of conventional chemotherapy is limited. Here, we present a case of metastatic iCCA harboring TFG-MET gene fusion, which demonstrated a remarkable response to treatment with capmatinib, a selective MET inhibitor. The patient was a 46-year-old man diagnosed with iCCA with hepatic, intraabdominal lymph nodes, and peritoneal metastases. Comprehensive genomic profiling (CGP) revealed TFG-MET gene fusion in his tumor. After becoming refractory to standard chemotherapy, he received capmatinib, which resulted in a marked shrinkage of the liver masses and lymph node metastases, as well as a drastic decrease in serum CA19-9 level. Our case reinforces the importance of CGP in exploring targeted therapy and supports the potential role of capmatinib in the treatment of tumors harboring MET fusions.

Multicenter retrospective analysis of complications and risk factors in endoscopic resection for esophageal cancer across Japan.

BACKGROUND: Endoscopic resection (ER) is a minimally invasive treatment for esophageal cancer that sometimes causes complications. To understand the real-world incidence and risk factors for these complications, a nationwide survey was conducted across Japan. METHODS: This retrospective multicenter study included patients who underwent ER for esophageal cancer from April 2017 to March 2018 (2017 complication analysis) and April 2021 to March 2022 (2021 complication analysis). The study assessed the complication rates and conducted risk factor analyses for endoscopic submucosal dissection (ESD) using data for these patients, with exclusions based on specific criteria to ensure data accuracy. RESULTS: In the 2021 complication analysis, there were two mortalities highly likely attributable (0.03%) to ER and one mortality possibly attributable (0.01%) to ER. Intraoperative perforation, delayed bleeding, and pneumonia occurred in 137 cases (1.8%), 44 cases (0.6%), and 130 cases (1.7%), respectively. In the multivariate analysis for complications after ESD, low ER volume of the facility was an independent risk factor for perforation, while lesion location in the cervical or upper thoracic esophagus was an independent factor for reduced risk of perforation. Age ≥ 80 years was a risk factor for pneumonia, while use of traction techniques was a factor for reduced risk of pneumonia. Lesions located in the middle thoracic esophagus had a lower risk of stricture, and the risk of stricture increased as the circumferential extent of the lesion increased. CONCLUSIONS: This large-scale study provided detailed insights into the complications associated with esophageal ER and identified significant risk factors.

Barriers and Facilitators to the Implementation of an Electronic Patient-Reported Outcome System at Cancer Hospitals in Japan.

Background and objective Implementing electronic patient-reported outcomes (ePROs) in oncology practice has shown substantial clinical benefits. However, it can be challenging in routine practice, warranting strategies to adapt to different clinical contexts. In light of this, this study aimed to describe the implementation process of the ePRO system and elucidate the provider-level implementation barriers and facilitators to a novel ePRO system at cancer hospitals in Japan. Methods We implemented an ePRO system linked to electronic medical records at three cancer hospitals. Fifteen patients with solid cancers at the outpatient oncology unit were asked to regularly complete the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE™) questionnaire and European Organization for Research and Treatment Core Quality of Life questionnaire (EORTC QLQ C30) by using the smartphone app between October 2021 and June 2022. Thirteen healthcare professionals were interviewed to identify implementation barriers and facilitators to the ePRO system by using the Consolidated Framework for Implementation Research framework. Results The healthcare professionals identified a lack of clinical resources and a culture and system that emphasizes treatment over care as the main barriers; however, the accumulation of successful cases, the leadership of managers, and the growing needs of patients can serve as facilitators to the implementation. Conclusions Our experience implementing an ePRO system in a few Japanese oncology practices revealed comprehensive barriers and facilitators. Further efforts are warranted to develop more successful implementation strategies.

Comparison of Effective Imaging Modalities for Detecting Gastric Neoplasms: A Randomized 3-Arm Phase II Trial.

INTRODUCTION: The early detection of gastric neoplasms (GNs) leads to favorable treatment outcomes. The latest endoscopic system, EVIS X1, includes third-generation narrow-band imaging (3G-NBI), texture and color enhancement imaging (TXI), and high-definition white-light imaging (WLI). Therefore, this randomized phase II trial aimed to identify the most promising imaging modality for GN detection using 3G-NBI and TXI. METHODS: Patients with scheduled surveillance endoscopy after a history of esophageal cancer or GN or preoperative endoscopy for known esophageal cancer or GN were randomly assigned to the 3G-NBI, TXI, or WLI groups. Endoscopic observations were performed to detect new GN lesions, and all suspected lesions were biopsied. The primary endpoint was the GN detection rate during primary observation. Secondary endpoints were the rate of missed GNs, early gastric cancer detection rate, and positive predictive value for a GN diagnosis. The decision rule had a higher GN detection rate between 3G-NBI and TXI, outperforming WLI by >1.0%. RESULTS: Finally, 901 patients were enrolled and assigned to the 3G-NBI, TXI, and WLI groups (300, 300, and 301 patients, respectively). GN detection rates in the 3G-NBI, TXI, and WLI groups were 7.3, 5.0, and 5.6%, respectively. The rates of missed GNs were 1.0, 0.7, and 1.0%, the detection rates of early gastric cancer were 5.7, 4.0, and 5.6%, and the positive predictive values for the diagnosis of GN were 36.5, 21.3, and 36.8% in the 3G-NBI, TXI, and WLI groups, respectively. DISCUSSION: Compared with TXI and WLI, 3G-NBI is a more promising modality for GN detection.

Colorectal cancer harboring EGFR kinase domain duplication response to EGFR tyrosine kinase inhibitors.

Epidermal growth factor receptor kinase domain duplication (EGFR-KDD) is a rare, recurrent oncogenic variant that constitutively activates EGFR in non-small-cell lung cancer. Herein, we report the case of a 70-year-old man with resectable colorectal adenocarcinoma who underwent surgery followed by adjuvant therapy. He relapsed with multiple liver metastases and received standard chemotherapy until his disease became refractory. Comprehensive genomic profiling of his postoperative colorectal cancer tissue revealed EGFR-KDD. He was treated with an EGFR tyrosine kinase inhibitor (TKI), afatinib and achieved a partial response (- 55%) after 8 weeks; however, he developed massive malignant ascites after 13 weeks. Osimertinib, another EGFR-TKI, controlled his tumors for 9 months. Patient-derived cancer organoids from his malignant ascites confirmed sensitivity to EGFR-TKIs. The findings suggest that EGFR-TKIs can be a potential treatment option for this molecular subgroup.

Japanese Classification of Esophageal Cancer, 12th Edition: Part I.

This is the first half of English edition of Japanese Classification of Esophageal Cancer, 12th Edition that was published by the Japan Esophageal Society in 2022.

SMARCA4-Deficient Poorly Differentiated Adenocarcinoma of the Gallbladder.

ABSTRACT: A 64-year-old woman presented with chest pain while eating and was referred to our hospital. Physical examination revealed abdominal distension, tenderness, and lower-extremity edema. Imaging revealed a large gallbladder tumor infiltrating the liver, with ascites and pleural effusion. A biopsy confirmed a poorly differentiated adenocarcinoma with SMARCA4 deficiency (cT3N2M1, cStage IV). Chemotherapy was ineffective and led to tumor progression. The patient died 9 months later. Recently, attention has been paid to SMARCA4 deficiency, which is a genetic mutation found in tumors. Here, we report on poorly differentiated adenocarcinomas of the gallbladder based on imaging findings, including FDG PET.

Japanese Classification of Esophageal Cancer, 12th Edition: Part II.

This is the second half of English edition of Japanese Classification of Esophageal Cancer, 12th Edition that was published by the Japan Esophageal Society in 2022.

Low serum concentrations of bevacizumab and nivolumab owing to excessive urinary loss in patients with proteinuria: a case series.

PURPOSE: Proteinuria can cause interindividual variability in the pharmacokinetics of therapeutic antibodies and may affect therapeutic efficacy. Here, we measured the serum and urinary concentrations of bevacizumab (BV) and nivolumab (NIVO) in patients with proteinuria and reported a case series of these patients. METHODS: Thirty-two cancer patients who received BV every 3 weeks or NIVO every 2 weeks between November 2020 and September 2021 at Kyoto University Hospital were enrolled in this study. The serum and urinary concentrations of BV and NIVO were measured using liquid chromatography-tandem mass spectrometry. RESULTS: We divided the BV-treated patients and the NIVO-treated patients into two groups based on the urine protein-creatinine ratio (UPCR): UPCR 1 g/g or higher (BV, n = 9; NIVO, n = 3) and UPCR less than 1 g/g (BV, n = 14; NIVO, n = 6). Serum concentrations of the therapeutic antibodies adjusted by their doses were significantly lower in both BV- and NIVO-treated patients with UPCR 1 g/g or higher compared to those with less than 1 g/g. In patients with UPCR 1 g/g or higher, urinary concentrations of the therapeutic antibodies adjusted by their serum concentrations and urinary creatinine concentrations tended to increase. CONCLUSION: This case-series study suggests a possibility of reduction in serum concentrations of BV and NIVO in patients with proteinuria by urinary excretion of these drugs.

Response to capmatinib in a patient with neuroendocrine carcinoma of the gallbladder origin harboring MET amplification.

Neuroendocrine carcinoma (NEC) of the gallbladder origin is particularly rare, accounting for only 0.38% of primary malignancies of the gallbladder, and standard therapies are limited. The MET gene encodes the tyrosine kinase receptor, c-Met. Pathogenic variants of MET, such as MET exon 14 skipping and MET amplification, result in excessive downstream signaling that promotes tumor progression. A MET inhibitor, capmatinib, blocks signaling of c-Met and has been approved by the Food and Drug Administration for non-small cell lung cancer with MET exon 14 skipping. The effectiveness of capmatinib has been reported in other cancers with MET amplification, but NEC with MET variants has not been reported. Here, we present a case of a 72-year-old woman with NEC of the gallbladder with multiple liver and lymph node metastases, who was resistant to conventional chemotherapy including carboplatin plus etoposide as first-line treatment and irinotecan as second-line treatment, but she responded to capmatinib. After 6 weeks of treatment, CT scan showed a partial response (80% reduction in size), but after 13 weeks, regrowth of liver metastasis was observed. Herein, we report a meaningful efficacy of capmatinib to the patient of NEC of the gallbladder origin with MET amplification.

Remarkable response as a new indicator for endoscopic evaluation of local efficacy of non-surgical treatments for esophageal cancer.

In Japan, standard of care of the patients with resectable esophageal cancer is neoadjuvant chemotherapy (NAC) followed by esophagectomy. Patients unfitted for surgery or with unresectable locally advanced esophageal cancer are generally indicated with definitive chemoradiotherapy (CRT). Local disease control is undoubtful important for the management of patients with esophageal cancer, therefore endoscopic evaluation of local efficacy after non-surgical treatments must be essential. The significant shrink of primary site after NAC has been reported as a good indicator of pathological good response as well as favorable survival outcome after esophagectomy. And patients who could achieve remarkable shrink to T1 level after CRT had favorable outcomes with salvage surgery and could be good candidates for salvage endoscopic treatments. Based on these data, "Japanese Classification of Esophageal Cancer, 12th edition" defined the new endoscopic criteria "remarkable response (RR)", that means significant volume reduction after treatment, with the subjective endoscopic evaluation are proposed. In addition, the finding of local recurrence (LR) at primary site after achieving a CR was also proposed in the latest edition of Japanese Classification of Esophageal Cancer. The findings of LR are also important for detecting candidates for salvage endoscopic treatments at an early timing during surveillance after CRT. The endoscopic evaluation would encourage us to make concrete decisions for further treatment indications, therefore physicians treating patients with esophageal cancer should be well-acquainted with each finding.

Proteinuria frequency and subsequent renal dysfunction in bevacizumab-treated patients: a single center, retrospective, observational study.

BACKGROUND: Proteinuria is a common adverse event observed during treatment with antivascular endothelial growth factor (VEGF) antibodies. Proteinuria is a risk factor for renal dysfunction and cardiovascular complications in patients with chronic kidney disease. However, the association between anti-VEGF antibody-induced proteinuria and renal dysfunction or cardiovascular complications remains unclear. METHODS: This retrospective, observational study included patients with cancer that were treated with bevacizumab (BV) at Kyoto University Hospital (Kyoto, Japan) between January 2006 and March 2018. Adverse event rates were compared between patients who developed qualitative ≥ 2 + proteinuria and those who developed < 1 + proteinuria. Adverse events were defined as renal dysfunction (i.e., ≥ 57% decrease in the eGFR, compared to the rate at the initial treatment) and hospitalization due to BV-associated cardiovascular complications and other adverse events. RESULTS: In total, 734 patients were included in this analysis. Renal dysfunction was more common in patients with ≥ 2 + proteinuria than in those with < 1 + proteinuria (13/199, 6.5% vs. 12/535, 2.3%). Seven of these 13 patients with ≥ 2 + proteinuria had transient reversible renal dysfunction. Only four (2.0%) patients had BV-associated renal dysfunction. Of the 734 patients, six patients, 16 patients, and 13 patients were hospitalized because of the adverse events of cardiovascular complications, thromboembolisms, and cerebrovascular complications, respectively. No relationship was observed between these adverse events and proteinuria. CONCLUSION: BV treatment-induced proteinuria was not associated with renal dysfunction or other adverse events. Continuing BV with caution is a possible treatment option, even after proteinuria develops, in patients with cancer and a limited prognosis.

Recurrence-free survival as a surrogate endpoint for overall survival after neoadjuvant chemotherapy and surgery for oesophageal squamous cell carcinoma.

BACKGROUND: Overall survival is considered as one of the most important endpoints of treatment efficacy but often requires long follow-up. This study aimed to determine the validity of recurrence-free survival as a surrogate endpoint for overall survival in patients with surgically resectable advanced oesophageal squamous cell carcinoma (OSCC). METHODS: Patients with OSCC who received neoadjuvant cisplatin and 5-fluorouracil, or docetaxel, cisplatin and 5-fluorouracil, at 58 Japanese oesophageal centres certified by the Japan Esophageal Society were reviewed retrospectively. The correlation between recurrence-free and overall survival was assessed using Kendall's τ. RESULTS: The study included 3154 patients. The 5-year overall and recurrence-free survival rates were 56.6 and 47.7% respectively. The primary analysis revealed a strong correlation between recurrence-free and overall survival (Kendall's τ 0.797, 95% c.i. 0.782 to 0.812) at the individual level. Subgroup analysis showed a positive relationship between a more favourable pathological response to neoadjuvant chemotherapy and a higher τ value. In the meta-regression model, the adjusted R2 value at the institutional level was 100 (95% c.i. 40.2 to 100)%. The surrogate threshold effect was 0.703. CONCLUSION: There was a strong correlation between recurrence-free and overall survival in patients with surgically resectable OSCC who underwent neoadjuvant chemotherapy, and this was more pronounced in patients with a better response to neoadjuvant chemotherapy.

Patient survey on cancer genomic medicine in Japan under the national health insurance system.

In Japan, comprehensive genomic profiling (CGP) tests have been reimbursed under the national health care system for solid cancer patients who have finished standard treatment. More than 50,000 patients have taken the test since June 2019. We performed a nation-wide questionnaire survey between March 2021 and July 2022. Questionnaires were sent to 80 designated Cancer Genomic Medicine Hospitals. Of the 933 responses received, 370 (39.7%) were web based and 563 (60.3%) were paper based. Most patients (784, 84%) first learned about CGP tests from healthcare professionals, and 775 (83.1%) gave informed consent to their treating physician. At the time of informed consent, they were most worried about test results not leading to novel treatment (536, 57.4%). On a scale of 0-10, 702 respondents (75.2%) felt that the explanations of the test result were easy to understand (7 or higher). Ninety-one patients (9.8%) started their recommended treatment. Many patients could not receive recommended treatment because no approved drugs or clinical trials were available (102/177, 57.6%). Ninety-eight patients (10.5%) did not wish their findings to be disclosed. Overall satisfaction with the CGP test process was high, with 602 respondents (64.5%) giving a score of 7-10. The major reason for choosing 0-6 was that the CGP test result did not lead to new treatment (217/277, 78.3%). In conclusion, satisfaction with the CGP test process was high. Patients and family members need better access to information. More patients need to be treated with genomically matched therapy.

Successful Management of Malignant Pericarditis Using Nivolumab for Metastatic Esophageal Squamous Cell Carcinoma.

Esophageal cancer is a malignant disease with a poor prognosis and is one of the most common causes of cardiac metastasis. Malignant pericarditis may cause the repetitive accumulation of pericardial effusion, which can occasionally pose a clinical challenge. We herein report a case of malignant pericarditis in a patient with metastatic esophageal squamous cell carcinoma with cardiac tamponade, which was successfully managed with single pericardial drainage and systemic nivolumab monotherapy. This is the first case report to suggest that systemic therapy with nivolumab is a promising option for the management of malignant pericarditis.

Association between continuous cessation or reduction of drinking alcohol and improvement of multiple dysplastic lesions in patients with esophageal squamous cell carcinoma after endoscopic resection.

BACKGROUND: Multiple development of squamous cell carcinoma (SCC) in the upper aerodigestive tract has been explained by the 'field cancerization phenomenon' associated with alcohol drinking. Squamous dysplastic lesion is clinically visualised as a Lugol-voiding lesion (LVL) by chromoendoscopy. Whether cessation or reduction of alcohol drinking improves multiple LVL and reduces the risk of field cancerization has not been elucidated. METHODS: We analysed 330 patients with newly diagnosed superficial esophageal SCC (ESCC) enrolled in the cohort study. The grade of LVL was assessed in all patients every 6 months. We instructed the patients to stop smoking and drinking and recorded their drinking and smoking status every 6 months. RESULTS: Among 330 patients, we excluded 98 with no LVL or no drinking habit. Of the remaining 232 patients, 158 continuously ceased or reduced their drinking habit. Patients who ceased or reduced their drinking habit significantly showed improvement in the grade of LVL. Multivariate analysis showed that continuous cessation or reduction of drinking habit improved the grade of LVL (hazard ratio [HR] = 8.5, 95% confidence interval [CI] 1.7-153.8, p = 0.0053). Higher grade of LVL carried a high risk of multiple ESCC and head and neck SCC (HNSCC) (HR = 3.7, 95% CI 2.2-6.4, p < 0.0001). Improvement in LVL significantly decreased the risk of multiple ESCC and HNSCC (HR = 0.2, 95% CI 0.04-0.7, p = 0.009). CONCLUSIONS: This is the first report indicating that field cancerization was reversible and cessation or reduction of drinking alcohol could prevent multiple squamous dysplastic lesion and multiple ESCC and HNSCC development. CLINICAL TRIALS REGISTRY NUMBER: UMIN000001676.

Removal rate of 5-fluorouracil and its metabolites in patients on hemodialysis: a report of two cases of colorectal cancer patients with end-stage renal failure.

PURPOSE: Hyperammonemia is a serious adverse effect of 5-fluorouracil (5FU) administration. Hemodialysis can be used for its management, but detailed data on the concentrations and removal rate of 5FU and its metabolites during hemodialysis remain unclear. Here, we present two cases of hemodialysis patients with end-stage renal disease who received concurrent 5FU infusion. METHODS: Blood samples were collected from the hemodialysis circuit before and after the dialyzer during day 2 hemodialysis sessions, and from the internal shunt just before and after day 4 hemodialysis sessions. The serum levels of 5FU and its metabolites-α-fluoro-ß-alanine (FBAL) and monofluoroacetate (FA)-were measured using liquid chromatography-tandem mass spectrometry. RESULTS: Seven sets of blood samples were collected for case 1; the removal rates (mean ± standard deviation) of 5FU and FBAL by the dialyzer were 81.2 ± 23.2% and 96.1 ± 8.6%, respectively (p < 0.001). Three sets of blood samples were collected for case 2; the removal rates of 5FU and FBAL were 81.7 ± 3.9% and 94.8 ± 2.7%, respectively (p = 0.03). Twenty-seven sets of blood samples were collected for case 1; reductions in blood FBAL and FA levels were 49.3 ± 8.8% (p < 0.001) and 64.2 ± 30.3% (p = 0.04), respectively. Bayesian estimation yielded similar results. Three sets of blood samples were collected for case 2; reductions in the blood FBAL and FA levels were 49.9 ± 6.9% and 50.6 ± 33.0%, respectively. CONCLUSION: In this study, 5FU and its metabolite FBAL were directly removed from the blood by approximately 90% during hemodialysis, and the blood levels of FBAL and FA were reduced by approximately 50% with a single hemodialysis session.