The pyruvate-GPR31 axis promotes transepithelial dendrite formation in human intestinal dendritic cells.

The intestinal lumen is rich in gut microbial metabolites that serve as signaling molecules for gut immune cells. G-protein-coupled receptors (GPCRs) sense metabolites and can act as key mediators that translate gut luminal signals into host immune responses. However, the impacts of gut microbe-GPCR interactions on human physiology have not been fully elucidated. Here, we show that GPR31, which is activated by the gut bacterial metabolite pyruvate, is specifically expressed on type 1 conventional dendritic cells (cDC1s) in the lamina propria of the human intestine. Using human induced pluripotent stem cell-derived cDC1s and a monolayer human gut organoid coculture system, we show that cDC1s extend their dendrites toward pyruvate on the luminal side, forming transepithelial dendrites (TED). Accordingly, GPR31 activation via pyruvate enhances the fundamental function of cDC1 by allowing efficient uptake of gut luminal antigens, such as dietary compounds and bacterial particles through TED formation. Our results highlight the role of GPCRs in tuning the human gut immune system according to local metabolic cues.

Frequent mutations that converge on the NFKBIZ pathway in ulcerative colitis.

Chronic inflammation is accompanied by recurring cycles of tissue destruction and repair and is associated with an increased risk of cancer1-3. However, how such cycles affect the clonal composition of tissues, particularly in terms of cancer development, remains unknown. Here we show that in patients with ulcerative colitis, the inflamed intestine undergoes widespread remodelling by pervasive clones, many of which are positively selected by acquiring mutations that commonly involve the NFKBIZ, TRAF3IP2, ZC3H12A, PIGR and HNRNPF genes and are implicated in the downregulation of IL-17 and other pro-inflammatory signals. Mutational profiles vary substantially between colitis-associated cancer and non-dysplastic tissues in ulcerative colitis, which indicates that there are distinct mechanisms of positive selection in both tissues. In particular, mutations in NFKBIZ are highly prevalent in the epithelium of patients with ulcerative colitis but rarely found in both sporadic and colitis-associated cancer, indicating that NFKBIZ-mutant cells are selected against during colorectal carcinogenesis. In further support of this negative selection, we found that tumour formation was significantly attenuated in Nfkbiz-mutant mice and cell competition was compromised by disruption of NFKBIZ in human colorectal cancer cells. Our results highlight common and discrete mechanisms of clonal selection in inflammatory tissues, which reveal unexpected cancer vulnerabilities that could potentially be exploited for therapeutics in colorectal cancer.

Identification of a unique subset of tissue-resident memory CD4+ T cells in Crohn's disease.

T cells differentiate into highly diverse subsets and display plasticity depending on the environment. Although lymphocytes are key mediators of inflammation, functional specialization of T cells in inflammatory bowel disease (IBD) has not been effectively described. Here, we performed deep profiling of T cells in the intestinal mucosa of IBD and identified a CD4+ tissue-resident memory T cell (Trm) subset that is increased in Crohn's disease (CD) showing unique inflammatory properties. Functionally and transcriptionally distinct CD4+ Trm subsets are observed in the inflamed gut mucosa, among which a CD-specific CD4+ Trm subset, expressing CD161 and CCR5 along with CD103, displays previously unrecognized pleiotropic signatures of innate and effector activities. These inflammatory features are further enhanced by their spatial proximity to gut epithelial cells. Furthermore, the CD-specific CD4+ Trm subset is the most predominant producer of type 1 inflammatory cytokines upon various stimulations among all CD4+ T cells, suggesting that the accumulation of this T cell subset is a pathological hallmark of CD. Our results provide comprehensive insights into the pathogenesis of IBD, paving the way for decoding of the molecular mechanisms underlying this disease.

Molecular and clinicopathological features of KIT/PDGFRA wild-type gastrointestinal stromal tumors.

Approximately 10% of gastrointestinal stromal tumors (GISTs) harbor reportedly no KIT and PDGFRA mutations (wild-type GISTs). The clinicopathological features and oncologic outcomes of wild-type GISTs based on molecular profiles are unknown. We recruited 35 wild-type GIST patients from the two registry studies of high-risk GISTs between 2012 and 2015 and primary GISTs between 2003 and 2014. Molecular profiling of wild-type GISTs was performed by targeted next-generation sequencing (NGS) using formalin-fixed paraffin-embedded tumor samples. Among 35 wild-type GISTs, targeted NGS analysis detected NF1, SDH, or BRAF mutation: 16 NF1-GISTs with various NF1 mutations, 12 SDH-GISTs (4 with SDHA mutations, 4 with SDHB mutations, and 4 with SDHB-negative staining), and 5 BRAF-GISTs with the V600E mutation. Two GISTs showed no mutations based on our targeted NGS analysis. Additional gene mutations were infrequent in primary wild-type GISTs and found in TP53, CREBBP, CDKN2A, and CHEK2. Most NF1-GISTs were located in the small intestine (N = 12; 75%) and showed spindle cell features (N = 15; 94%) and multiple tumors (N = 6, 38%) with modest proliferation activities. In contrast, SDH-GISTs were predominantly found in the stomach (N = 11; 92%), exhibiting epithelioid cell (N = 6; 50%) and multiple (N = 6, 50%) features. The overall survival of patients with SDH-GISTs appeared to be better than that of BRAF-GISTs (p = 0.0107) or NF1-GISTs (p = 0.0754), respectively. In conclusion, major molecular changes in wild-type GISTs include NF1, SDH, and BRAF. NF1-GISTs involved multifocal spindle cell tumors in the small intestine. SDH-GISTs occurred in young patients and were multifocal in the stomach and clinically indolent.

The cytokine profile correlates with less tumor-infiltrating lymphocytes in luminal A breast cancer.

PURPOSE: Tumor-infiltrating lymphocyte (TIL) levels are prognostic and predictive factors for breast cancer. Unlike other subtypes, most luminal A breast cancers are immune deserts; however, the underlying mechanisms are poorly understood. METHODS: Immune-related cytokines, chemokines, and growth factors were measured in the sera of 103 patients with breast cancer using a multiplex panel. The TILs were evaluated for hotspot lesions. RESULTS: Circulating interleukin 1 receptor antagonist (IL-1ra), IL-8, IL-12, IL-17, macrophage inflammatory protein-1ß (MIP-1b), and platelet-derived growth factor B homodimer (PDGF-bb) concentrations were significantly associated with TIL levels. Cluster analysis using these six variables identified six clusters related to TIL levels. Breast cancers with high TILs (≥ 50%) were most frequent in cluster 3 (9 out of 15 cases, 60.0%), followed by cluster 1 (8 out of 34 cases, 23.5%), and the fewest in cluster 6 (1 out of 21 cases, 4.8%), whereas only one or three cases were present in clusters 2, 4, and 5 (p = 0.0064). Cluster 6, consisting mostly of luminal A (19 out of 21 cases, 90.5%), showed high levels of IL-12, IL-17, and PDGF-bb, and low levels of MIP-1b. CONCLUSION: We identified a luminal A-associated immunosuppressive cytokine signature in circulation. These results suggest that a tumor microenvironment with high levels of IL-17 and PDGF-bb, and low levels of MIP-1b in luminal A breast cancers results in low induction of TILs. Our data may partially explain the low TIL levels observed in the patients with luminal A breast cancer.

Anti-tumor effect of antibody-drug conjugate targeting cell adhesion molecule 1 on GIST cells representing small intestinal GIST.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the alimentary tract. The prognosis depends on the primary site, and small intestinal GISTs have a worse prognosis than gastric GISTs. Molecularly targeted drugs to inhibit tyrosine kinase activity of KIT were used for unresectable or recurrent GISTs. However, secondary resistance to the drugs is often acquired, and treatments based on other mechanisms are needed. Previously, we reported that cell adhesion molecule 1 (CADM1) was highly expressed in most of small intestinal GISTs but not in most of gastric GISTs. In the present study, we examined whether the antibody-drug conjugate (ADC) with anti-CADM1 antibody and monomethyl auristatin E (anti-CAD-ADC) shows anti-tumor effect on CADM1-expressing human GIST cells. The ADC adhibited in this study was previously used for CADM1-expressing human mesothelioma cells and showed anti-tumor effect for them in vitro. GIST-T1 cell line of gastric origin which scarcely expresses CADM1 and GIST-T1 cells transfected with CADM1 cDNA (GIST-T1-CAD cells) which highly expresses CADM1 and represents small intestinal GIST were used. In vitro, anti-CAD-ADC showed remarkable cytotoxic activity on GIST-T1-CAD cells, but control ADC did not. Both anti-CAD-ADC and control ADC did not show anti-tumor effect on original GIST-T1 cells. When GIST-T1-CAD cells were subcutaneously injected to the nude mice, intravenous administration of anti-CAD-ADC showed inhibitory effect for tumor enlargement. Tumor of GIST-T1 cells grew even after anti-CAD-ADC injection. When GIST-T1-CAD cells were injected into peritoneal cavity of the SCID mice, intraperitoneal administration of anti-CAD-ADC showed reduction of the peritoneal tumor. On the other hand, peritoneal tumor grew after control ADC administration. Tissue and organ damage due to administration of anti-CAD-ADC was not apparent by macroscopic and histological examinations in mice. These results indicate that anti-CAD-ADC could have apparent anti-tumor effect on CADM1-expressing human GIST cells both in in vitro and in vivo mouse models.

The impact of contour maps on estimating the risk of gastrointestinal stromal tumor recurrence: indications for adjuvant therapy: an analysis of the Kinki GIST registry.

INTRODUCTION: Contour maps enable risk classification of GIST recurrence in individual patients within 10 postoperative years. Although contour maps have been referred to in Japanese guidelines, their usefulness and role in determining indications for adjuvant therapy is still unclear in Japanese patients. The aims of this study are to investigate the validity of contour maps in Japanese patients with GIST and explore the new strategy for adjuvant therapy. MATERIALS AND METHODS: A total of 1426 Japanese GIST patients who were registered to the registry by the Kinki GIST Study Group between 2003 and 2012 were analyzed. Patients who had R0 surgery without perioperative therapy were included in this study. The accuracy of contour maps was validated. RESULTS: Overall, 994 patients have concluded this study. Using contour maps, we validated the patients. The 5-year recurrence-free survival rates of patients within the GIST classification groups of 0-10%, 10-20%, 20-40%, 40-60%, 60-80%, 80-90%, and 90-100% were 98.1%, 96.6%, 92.3%, 48.0%, 37.3%, 41.0% and 42.4%, respectively. We confirmed that this classification by contour maps was well reflected recurrence prediction. Further, in the high-risk group stratified by the modified National Institutes of Health consensus criteria (m-NIHC), the 10-year RFS rate was remarkably changed at a cutoff of 40% (0-40% group vs. 40-100% group: 88.7% vs. 50.3%, p < 0.001). CONCLUSION: Contour maps are effective in predicting individual recurrence rates. And it may be useful for the decision of individual strategy for high-risk patients combined with m-NIHC.

English version of Japanese Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) issued by the Japan Society of Clinical Oncology.

The Japan Society of Clinical Oncology Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) have been published in accordance with the Minds Manual for Guideline Development 2014 and 2017. A specialized team independent of the working group for the revision performed a systematic review. Since GIST is a rare type of tumor, clinical evidence is not sufficient to answer several clinical and background questions. Thus, in these guidelines, we considered that consensus among the experts who manage GIST, the balance between benefits and harms, patients' wishes, medical economic perspective, etc. are important considerations in addition to the evidence. Although guidelines for the treatment of GIST have also been published by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO), there are some differences between the treatments proposed in those guidelines and the treatments in the present guidelines because of the differences in health insurance systems among countries.

A case of non-Hodgkin lymphoma of the upper gingiva with minimal residual disease detected in cryopreserved ovarian tissue: A case report.

Recently, more than 200 live births following ovarian tissue cryopreservation (OTC) and transplantation in cancer survivors have been reported worldwide. However, cancer survivors with minimal residual disease (MRD) in cryopreserved ovarian tissue are at the risk of relapse through the graft. Here, we report a rare case of a 19-year-old female patient with non-Hodgkin lymphoma who had MRD in the ovary harvested for OTC. The patient was diagnosed with aggressive B-cell lymphoma after gingival biopsy. The 18F-fluoro-2-deoxy-D-glucose positron emission tomography scan performed before OTC showed no viable lesions in either ovary. However, on histological evaluation, we detected infiltration of lymphoma cells in the ovary. Informed consent about MRD is required even if there is no evidence of MRD in the ovary before OTC. Patients whose cryopreserved ovaries have MRD may require the development of alternative assisted reproductive technologies such as in vitro growth or artificial ovary.

Combination of pimitespib (TAS-116) with sunitinib is an effective therapy for imatinib-resistant gastrointestinal stromal tumors.

Despite the effectiveness of imatinib, most gastrointestinal stromal tumors (GISTs) develop resistance to the treatment, mainly due to the reactivation of KIT tyrosine kinase activity. Sunitinib, which inhibits the phosphorylation of KIT and vascular endothelial growth factor (VEGF) receptor, has been established as second-line therapy for GISTs. The recently-developed heat shock protein 90 (HSP90) inhibitor pimitespib (PIM; TAS-116) demonstrated clinical benefits in some clinical trials; however, the effects were limited. The aim of our study was therefore to clarify the effectiveness and mechanism of the combination of PIM with sunitinib for imatinib-resistant GISTs. We evaluated the efficacy and mechanism of the combination of PIM with sunitinib against imatinib-resistant GIST using imatinib-resistant GIST cell lines and murine xenograft models. In vitro analysis demonstrated that PIM and sunitinib combination therapy strongly inhibited growth and induced apoptosis in imatinib-resistant GIST cell lines by inhibiting KIT signaling and decreasing auto-phosphorylated KIT in the Golgi apparatus. In addition, PIM and sunitinib combination therapy enhanced antitumor responses in the murine xenograft models compared to individual therapies. Further analysis of the xenograft models showed that the combination therapy not only downregulated the KIT signaling pathway but also decreased the tumor microvessel density. Furthermore, we found that PIM suppressed VEGF expression in GIST cells by suppressing protein kinase D2 and hypoxia-inducible factor-1 alpha, which are both HSP90 client proteins. In conclusion, the combination of PIM and sunitinib is effective against imatinib-resistant GIST via the downregulation of KIT signaling and angiogenic signaling pathways.

Long-term outcomes of a phase II study of neoadjuvant imatinib in large gastrointestinal stromal tumors of the stomach.

BACKGROUND: Neoadjuvant treatment is recommended for large GISTs due to their friability and risk of extensive operations; however, studies on the indications and long-term results of this approach are lacking. METHODS: Patients with large (≥ 10 cm) gastric GISTs were enrolled from multiple centers in Korea and Japan after a pathologic confirmation of c-KIT ( +) GISTs. Imatinib (400 mg/d) was given for 6-9 months preoperatively, and R0 resection was intended. Postoperative imatinib was given for at least 12 months and recommended for 3 years. RESULTS: A total of 56 patients were enrolled in this study, with 53 patients receiving imatinib treatment at least once and 48 patients undergoing R0 resection. The 5-year overall survival and progression-free survival rates were 94.3% and 61.6%, respectively. Even patients with stable disease by RECIST criteria responded well to preoperative imatinib treatment and could undergo R0 resection, with most being evaluated as partial response by CHOI criteria. The optimal reduction in tumor size was achieved with preoperative imatinib treatment for 24 weeks or more. No resumption of imatinib treatment was identified as an independent prognostic factor for recurrence after R0 resection. No additional size criteria for a higher risk of recurrence were identified in this cohort with a size of 10 cm or more. CONCLUSIONS: Neoadjuvant imatinib treatment is an effective treatment option for gastric GISTs 10 cm or larger. Postoperative imatinib treatment is recommended even after R0 resection to minimize recurrence.

Sunitinib therapy for imatinib-resistant and/or intolerant gastrointestinal stromal tumors: comparison of safety and efficacy between standard and reduced dosage regimens.

BACKGROUND: Sunitinib therapy for patients with imatinib-resistant and/or intolerant gastrointestinal stromal tumors (GISTs) often causes severe adverse events (AEs) that lead to treatment discontinuation. METHODS: We retrospectively reviewed the clinical records of imatinib-resistant and/or intolerant GIST patients who underwent sunitinib therapy in our institutions between 2007 and 2020. Forty-one patients were enrolled and divided into two groups on the basis of the starting dosage: the standard dosage group (50 mg/day, 21 patients) and the reduced dosage group (37.5 mg/day, 20 patients). Tolerability, safety and clinical efficacy of the two groups were compared. RESULTS: Three patients (14%) in the standard dosage group and another three (15%) in the reduced dosage group (P = 1.000) discontinued sunitinib therapy because of AEs. The incidences of grade 3 or more severe treatment-related AEs were 90 and 75%, respectively (P = 0.238). Two possible treatment-related deaths were noted in the standard dosage group. Clinical efficacy was comparable between the two groups: median time to treatment failure and overall survival were 4.5 months [interquartile range (IQR), 3.6-9.0] and 13.7 months (IQR, 7.5-22.9) in the standard dosage group and 4.6 months (IQR, 2.7-17.0) and 13.4 months (IQR, 9.3-36.8) in the reduced dosage group, respectively. CONCLUSIONS: The reduced dosage of 37.5 mg sunitinib tended to decrease toxicity and the incidences of severe AEs and treatment-related deaths. This reduced dosage regimen showed equivalent clinical efficacy including patient survival. The reduced dosage of 37.5 mg sunitinib can be adopted as an alternative therapy for patients with imatinib-resistant and/or intolerant GISTs.

Characterization of cell line with dedifferentiated GIST-like features established from cecal GIST of familial GIST model mice.

Approximately 40 families with multiple gastrointestinal stromal tumors (GISTs) and germline c-kit gene mutations have been reported. Three knock-in mouse models have been generated, and all the models showed a cecal GIST. In the present study, we established a cell line derived from cecal GIST in a familial GIST model mouse with KIT-Asp818Tyr. Since the established cells showed spindle-shaped morphology with atypical nuclei, and since immunohistochemistry revealed that they were positive for α-SMA but negative for KIT, CD34 and desmin, the phenotypes of the cells were reminiscent of dedifferentiated GIST-like ones but not the usual GIST-like ones. Gene expression analysis showed that the cell line, designated as DeGISTL1 cell, did not express c-kit gene apparently, but highly expressed HSP90 families and glutaminase 1. Pathway analysis of the cells revealed that metabolic pathway might promote their survival and growth. Pimitespib, a heat shock protein 90α/ß inhibitor, and Telaglenastat, a selective glutaminase 1 inhibitor, inhibited proliferation of DeGISTL1 cells and the combination of these showed an additive effect. DeGISTL1 cells might be a good model of dedifferentiated GISTs, and combination of Pimitespib and Telaglenastat could be a possible candidate for treatment strategy for them.

Plasma trough concentration of imatinib and its effect on therapeutic efficacy and adverse events in Japanese patients with GIST.

BACKGROUND: Imatinib mesylate (IM) is the standard chemotherapy for patients with gastrointestinal stromal tumors (GISTs) and has a favorable safety profile. Pharmacokinetics (PK), such as plasma trough concentration (Cmin), varies among patients, requiring the need for therapeutic drug monitoring (TDM) during IM administration. Despite some reports from overseas, the relationship between Cmin, adverse events (AEs), and treatment efficacy in Japanese patients with GIST has still been lacking. This study aimed to investigate the relationship between IM plasma concentration and AEs in Japanese patients with GISTs. METHODS: This retrospective study analyzed the data of 83 patients who underwent IM treatment for GISTs at our institution between May 2002 and September 2021. RESULTS: The IM Cmin was associated with any grade of AEs (with AEs vs. without AEs = 1294 (260-4075) vs. 857 (163-1886) ng/mL, P < 0.001), edema (with edema vs. without edema = 1278 (634-4075) vs. 1036 (163-4069) ng/mL, P = 0.017), and fatigue (with fatigue vs. without fatigue = 1373 (634-4069) vs. 1046 (163-4075) ng/mL, P = 0.044). Moreover, a Cmin ≥ 1283 ng/mL was a risk factor for severe AEs. The median progression-free survival (PFS) was 3.04 years in the lowest Cmin tertile (T1, < 917 ng/mL) compared with 5.90 years for T2 and T3 (P = 0.010). CONCLUSION: Edema and fatigue are potentially associated with IM plasma trough concentrations of ≥ 1283 ng/mL in Japanese patients with GISTs. Further, maintaining an IM plasma trough concentration above 917 ng/mL may improve PFS.

Primordial follicles remaining in young cancer survivors who received chemotherapy.

AIM: Ovarian tissue cryopreservation (OTC) is performed for fertility preservation in cancer patients undergoing chemotherapy. Although anti-Müllerian hormone is used as a marker for ovarian reserve, serum levels do not always correlate with the number of follicles. Additionally, the follicle development stage most affected by chemotherapy is unclear. We examined the association between serum anti-Müllerian hormone levels and the number of remaining primordial follicles after chemotherapy, as well as which follicle stage is most affected by chemotherapy before ovarian cryopreservation. METHODS: Thirty-three patients who underwent OTC were divided into the chemotherapy (n = 22) and non-chemotherapy (n = 11) groups; their ovarian tissues underwent histological examination. Pathological ovarian damage induced by chemotherapy was assessed. Ovarian volumes were estimated from weights. We compared the number of follicles at each developmental stage as a percentage of primordial follicles between the groups. The relationship between serum anti-Müllerian hormone level and primordial follicle density was analyzed. RESULTS: The chemotherapy group had a significantly lower serum anti-Müllerian hormone level, ovarian volume, and density of developing follicles than the non-chemotherapy group. Serum anti-Müllerian hormone levels correlated with primordial follicle density only in the non-chemotherapy group. The chemotherapy group had significantly lower numbers of primary and secondary follicles. CONCLUSIONS: Chemotherapy induces ovarian damage and follicle loss. However, serum anti-Müllerian hormone level does not always reflect the number of primordial follicles after chemotherapy, and chemotherapy more significantly affects primary and secondary follicles than primordial follicles. Many primordial follicles remain in the ovary after chemotherapy, supporting OTC for fertility preservation.

Frequency and Distribution of Sheet and Nodular Calcification in Coronary Arteries in Japanese Patients.

Whether a nodular calcification (NC), which is the precursor to intracoronary thrombosis, is focally or diffusely distributed in the coronary tree has major implications for ongoing efforts to identify. This study aimed to investigate the frequency and spatial distribution patterns of sheet calcification (SC) and NC in a 3-vessel examination of autopsied human hearts.A total of 323 coronary artery specimens from 110 cadavers were obtained from autopsy cases. After fixation and decalcification, the coronary artery trees were cut every 5 mm into 4-µm transverse cross-sections for histological assessment. An SC was defined as a plate-like calcification of > 1 quadrant of the vessel or > 3 mm in diameter, and NC as nodular calcium deposits separated by fibrin, and a deposit size > 1 mm in diameter.Of the 6,306 histological cross-sections, SCs and NCs were identified in 1,627 (26%) and 233 (4%) cross-sections, respectively. SCs and NCs had a similar distribution pattern in all 3 coronary arteries. In the left anterior descending artery (LAD), NCs were predominantly located in the proximal segment: the first 45 mm from the LAD ostium (72%) and the first 60 mm from the LAD ostium (84%), respectively. However, NCs were evenly distributed throughout the length of the coronary artery in the right coronary artery (RCA) and left circumflex artery (LCX).NCs coexisted with SCs, and tended to cluster in predictable parts within the proximal segments of the LAD, but were evenly distributed throughout the RCA and LCX in coronary arteries from cadavers.

[Port Site Recurrence After Laparoscopic Nephrectomy for Renal Cell Carcinoma --Report of Two Cases and Literature review-].

CASE 1: A male in his 60s underwent a right transperitoneal laparoscopic partial nephrectomy procedure for a right renal tumor. Rupture of a renal cyst located close to the tumor occurred intraoperatively. The histopathological diagnosis was clear cell renal cell carcinoma (CCRCC), pT1aN0M0, G2, v0, with negative resection margins. At 84 months after surgery, computed tomography (CT) revealed a 10 mm mass in the rectus abdominis muscle at the camera port site used for the partial nephrectomy. An open lumpectomy was then performed and the histopathological diagnosis was CCRCC. One year later, a 40 mm sized mass was detected in the mesentery of the small intestine by CT, which was removed laparoscopically with part of the mesentery and diagnosed as CCRCC. Since that surgery, the patient has been free from recurrence for 8 years. CASE 2: A male in his 60s underwent a left retroperitoneal laparoscopic nephrectomy procedure for a left renal tumor. The histopathological diagnosis was CCRCC, pT1aN0M0, G1, v0, with negative resection margins. At 31 months after surgery, CT revealed a 32 mm mass in the retroperitoneal cavity at the right hand port site used for the laparoscopic nephrectomy. The mass was removed with part of the twelfth rib and erector spinae muscles in a lump, and the histopathological diagnosis was CCRCC. Since that surgery, the patient has been free from recurrence for 19 months. For the treatment of solitary port site recurrence of renal cell carcinoma after a laparoscopic radical/partial nephrectomy, we recommend surgical resection for a good prognosis.

Long-term adjuvant therapy for high-risk gastrointestinal stromal tumors in the real world.

PURPOSE: Three years of adjuvant imatinib is the standard therapy for gastrointestinal stromal tumors (GISTs) with high-risk features. The prognostic effects of long-term adjuvant therapy are unknown. PATIENTS AND METHODS: The prospective registry study recruited 515 patients with high-risk GISTs between Dec. 2012 and Dec. 2015 were analyzed. The primary endpoint was recurrence-free survival (RFS), and secondary endpoints include overall survival (OS) and safety. The study was designed to compare RFS after 3.5 years of 3-year adjuvant therapy (3.0 ± 0.5 years: 3-year group) with that of more than 3.5 years (median 5.2 years: longer group). RESULTS: Five-year RFS and 5-year OS were 68.2% (95% confidence interval [CI] 63.8-72.1) and 92.3% (95% CI 89.5-94.4), respectively. The recurrence rate during adjuvant was estimated to be 2.9/100 person-years (95% CI 2.0-4.1) and those after the end of adjuvant, which appeared similar irrespective of the adjuvant duration or reason to stop adjuvant, were estimated 12.0/100 person-years (95% CI 10.2-14.0). The 5-year RFS rates of 3-year and longer groups were 78.7% (95% CI 70.8-84.7) and 92.7% (95% CI 85.2-96.4), respectively. RFS after 3.5 years of the longer group was significantly better than that of the 3-year group (adjusted hazard ratio [HR] 0.56; 95% CI 0.39-0.78; P < 0.001). CONCLUSION: The recurrence risk of high-risk GISTs after adjuvant therapy is similar irrespective of the adjuvant duration and imatinib adjuvant may not cure but may delay recurrence. RFS after long-term adjuvant therapy appeared better than that after 3-year adjuvant.

Efficacy and safety of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors.

BACKGROUND: Regorafenib is an oral multi-kinase inhibitor that has been established as third-line treatment for patients after the failure of imatinib and sunitinib. However, since clinical data of regorafenib in the Japanese population are still lacking, the management of regorafenib is mainly based on the clinical experience of each oncologist. The aim of this study was to evaluate the efficacy and safety of regorafenib in a Japanese population. METHODS: Thirty-three patients treated with regorafenib for metastatic and recurrent gastrointestinal stromal tumors were retrospectively enrolled. This study investigated the anti-tumor effect, including overall survival, progression-free survival, and safety, which was evaluated based on the incidence of adverse events. RESULTS: The median overall survival of patients treated with regorafenib was 23.8 months and the 1-year overall survival rate was 80.0%, the median progression-free survival was 7.1 months and the 1-year progression-free survival rate was 40.2%. The responses to regorafenib were partial response in 3 cases (9.1%), stable disease in 17 (51.5%), progressive disease in 10 (30.3%), and non-evaluable in 3 (9.1%). The disease control rate was 54.0%. Treatment-related adverse events were reported in all patients, with the most common being hand-foot syndrome (72.7%), followed by liver damage (36.4%) and diarrhea (27.3%), and six patients (20.0%) were discontinued due to adverse events. CONCLUSION: This is the first report of Japanese patients with gastrointestinal stromal tumors treated with regorafenib. Regorafenib showed efficacy and a manageable safety profile in Japanese patients with advanced gastrointestinal stromal tumors, which was comparable with previous studies.

Real-world data on the efficacy and safety of adjuvant chemotherapy in Japanese patients with a high-risk of gastrointestinal stromal tumor recurrence.

BACKGROUND: Complete surgical resection is the only treatment for resectable gastrointestinal stromal tumors (GISTs). Three-year adjuvant chemotherapy (AC) is recommended for patients with high-risk GISTs. However, there are scarce data on this topic in Japan. We aimed to study the efficacy and safety of AC in Japanese patients with high-risk GISTs. METHODS: Patients with high-risk GISTs who received complete resections during 1992-2019 in our hospitals were included in this retrospective study. We evaluated patients' treatments with or without AC, completion rates, adverse events (AEs), recurrence-free survival (RFS), and overall survival (OS). RESULTS: Overall, 89 patients categorized as high risk were enrolled in this study. Fifty-five patients received AC (AC group), and 34 patients did not receive AC (control group). Twenty-three (41.8%) patients experienced Common Terminology Criteria for Adverse Events Grade 2 or higher AEs. At a median follow-up of 61.6 months, 41 (74.5%) patients completed the planned treatment (including six patients with ongoing treatment), whereas 14 (25.4%) patients did not complete the treatment owing to the development of AEs (nine patients), patients' request (three patients), recurrence (one patient), and mutational analysis (one patient). Comparing the data between the treatment and control groups, the RFS rate was significantly better for the AC group (P < 0.001). However, there was no significant difference in the OS rate between the two groups. CONCLUSION: Postoperative AC was well tolerated by Japanese patients at an acceptable rate, and its use may reduce the risk of recurrence in patients with high-risk GISTs.