Circulating cell-free DNA methylation patterns as non-invasive biomarkers to monitor colorectal cancer treatment efficacy without referencing primary site mutation profiles.

This study investigates methylation patterns in circulating cell-free DNA (ccfDNA) for their potential role in colorectal cancer (CRC) detection and the monitoring of treatment response. Through methylation microarrays and quantitative PCR assays, we analyzed 440 samples from The Cancer Genome Atlas (TCGA) and an additional 949 CRC samples. We detected partial or extensive methylation in over 85% of cases within three biomarkers: EFEMP1, SFRP2, and UNC5C. A methylation score for at least one of the six candidate regions within these genes' promoters was present in over 95% of CRC cases, suggesting a viable detection method. In evaluating ccfDNA from 97 CRC patients and 62 control subjects, a difference in methylation and recovery signatures was observed. The combined score, integrating both methylation and recovery metrics, showed high diagnostic accuracy, evidenced by an area under the ROC curve of 0.90 (95% CI = 0.86 to 0.94). While correlating with tumor burden, this score gave early insight into disease progression in a small patient cohort. Our results suggest that DNA methylation in ccfDNA could serve as a sensitive biomarker for CRC, offering a less invasive and potentially more cost-effective approach to augment existing cancer detection and monitoring modalities, possibly supporting comprehensive genetic mutation profiling.

Overcoming immunotherapy resistance and inducing abscopal effects with boron neutron immunotherapy (B-NIT).

Immune checkpoint inhibitors (ICIs) are effective against many advanced malignancies. However, many patients are nonresponders to immunotherapy, and overcoming this resistance to treatment is important. Boron neutron capture therapy (BNCT) is a local chemoradiation therapy with the combination of boron drugs that accumulate selectively in cancer and the neutron irradiation of the cancer site. Here, we report the first boron neutron immunotherapy (B-NIT), combining BNCT and ICI immunotherapy, which was performed on a radioresistant and immunotherapy-resistant advanced-stage B16F10 melanoma mouse model. The BNCT group showed localized tumor suppression, but the anti-PD-1 antibody immunotherapy group did not show tumor suppression. Only the B-NIT group showed strong tumor growth inhibition at both BNCT-treated and shielded distant sites. Intratumoral CD8+ T-cell infiltration and serum high mobility group box 1 (HMGB1) levels were higher in the B-NIT group. Analysis of CD8+ T cells in tumor-infiltrating lymphocytes (TILs) showed that CD62L- CD44+ effector memory T cells and CD69+ early-activated T cells were predominantly increased in the B-NIT group. Administration of CD8-depleting mAb to the B-NIT group completely suppressed the augmented therapeutic effects. This indicated that B-NIT has a potent immune-induced abscopal effect, directly destroying tumors with BNCT, inducing antigen-spreading effects, and protecting normal tissue. B-NIT, immunotherapy combined with BNCT, is the first treatment to overcome immunotherapy resistance in malignant melanoma. In the future, as its therapeutic efficacy is demonstrated not only in melanoma but also in other immunotherapy-resistant malignancies, B-NIT can become a new treatment candidate for advanced-stage cancers.

Fibroblast activation protein-targeted near-infrared photoimmunotherapy depletes immunosuppressive cancer-associated fibroblasts and remodels local tumor immunity.

BACKGROUND: Cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) play a critical role in tumor immunosuppression. However, targeted depletion of CAFs is difficult due to their diverse cells of origin and the resulting lack of specific surface markers. Near-infrared photoimmunotherapy (NIR-PIT) is a novel cancer treatment that leads to rapid cell membrane damage. METHODS: In this study, we used anti-mouse fibroblast activation protein (FAP) antibody to target FAP+ CAFs (FAP-targeted NIR-PIT) and investigated whether this therapy could suppress tumor progression and improve tumor immunity. RESULTS: FAP-targeted NIR-PIT induced specific cell death in CAFs without damaging adjacent normal cells. Furthermore, FAP-targeted NIR-PIT treated mice showed significant tumor regression in the CAF-rich tumor model accompanied by an increase in CD8+ tumor infiltrating lymphocytes (TILs). Moreover, treated tumors showed increased levels of IFN-γ, TNF-α, and IL-2 in CD8+ TILs compared with non-treated tumors, suggesting enhanced antitumor immunity. CONCLUSIONS: Cancers with FAP-positive CAFs in their TME grow rapidly and FAP-targeted NIR-PIT not only suppresses their growth but improves tumor immunosuppression. Thus, FAP-targeted NIR-PIT is a potential therapeutic strategy for selectively targeting the TME of CAF+ tumors.

Long-term activation of anti-tumor immunity in pancreatic cancer by a p53-expressing telomerase-specific oncolytic adenovirus.

BACKGROUND: Pancreatic cancer is an aggressive, immunologically "cold" tumor. Oncolytic virotherapy is a promising treatment to overcome this problem. We developed a telomerase-specific oncolytic adenovirus armed with p53 gene (OBP-702). METHODS: We investigated the efficacy of OBP-702 for pancreatic cancer, focusing on its long-term effects via long-lived memory CD8 + T cells including tissue-resident memory T cells (TRMs) and effector memory T cells (TEMs) differentiated from effector memory precursor cells (TEMps). RESULTS: First, in vitro, OBP-702 significantly induced adenosine triphosphate (ATP), which is important for memory T cell establishment. Next, in vivo, OBP-702 local treatment to murine pancreatic PAN02 tumors increased TEMps via ATP induction from tumors and IL-15Rα induction from macrophages, leading to TRM and TEM induction. Activation of these memory T cells by OBP-702 was also maintained in combination with gemcitabine+nab-paclitaxel (GN) in a PAN02 bilateral tumor model, and GN + OBP-702 showed significant anti-tumor effects and increased TRMs in OBP-702-uninjected tumors. Finally, in a neoadjuvant model, in which PAN02 cells were re-inoculated after resection of treated-PAN02 tumors, GN + OBP-702 provided long-term anti-tumor effects even after tumor resection. CONCLUSION: OBP-702 can be a long-term immunostimulant with sustained anti-tumor effects on immunologically cold pancreatic cancer.

Perioperative and Postoperative Continuous Nutritional Counseling Improves Quality of Life of Gastric Cancer Patient Undergoing Gastrectomy.

Post-gastrectomy syndrome (PGS) and body weight loss (BWL) decrease quality of life (QOL) and survival of the patient undergoing gastrectomy. We have introduced perioperative and post-discharge continuous nutritional counseling (CNC) to prevent BWL and improve QOL after gastrectomy. In the present study, we evaluated the effect of CNC on QOL using the Post-gastrectomy Syndrome Assessment Scale-45 (PGSAS-45). Eighty-three patients with gastric cancer (GC) who underwent curative gastrectomy between March 2018 and July 2019 were retrospectively analyzed. Patients received either pre-discharge nutritional counseling alone (control group, n = 45) or CNC (CNC group, n = 38) after gastrectomy. QOL at 12 months after gastrectomy was compared between the two groups. In QOL assessment, change in body weight (-7.98% vs. -12.77%, p = 0.0057), ingested amount of food per meal (7.00 vs. 6.07, p = 0.042) and ability for working (1.89 vs. 2.36, p = 0.049) were significantly better in CNC group than control group. Multiple regression analysis showed that CNC was a significantly beneficial factor for abdominal pain subscale (p = 0.028), diarrhea subscale (p = 0.047), ingested amount of food per meal (p = 0.012), Ability for working (p = 0.031) and dissatisfaction at the meal (p = 0.047). Perioperative and postoperative CNC could improve QOL in the patient undergoing gastrectomy in addition to preventing postoperative BWL.

Laparoscopic Resection Combined with a Transsacral Approach for a Recurrent Tailgut Cyst with a Refractory Fistula.

Tailgut cyst is a rare cystic disease of the anterior sacral surface and the remains of an embryonic tail gut. Tailgut cysts have a potential for malignancy, and complete resection with an adequate surgical margin is necessary. Even if incomplete resection does not result in recurrence of malignant disease, there is a risk of local infection leading to refractory fistulas. The optimal treatment for such refractory recurrent lesions has not been reported. We describe a case in which the combination of laparoscopic and transsacral approaches was effective for resecting a recurrent refractory fistula after incomplete resection of a tail gut cyst.

Perineal Squamous Cell Carcinoma Arising in an Epidermal Cyst.

A 90-year-old Japanese woman who had been aware of a subcutaneous mass on the right perineal region for 5 years was referred to our hospital for further examination and treatment because of the rapid growth of the mass and bleeding that began 3 months earlier. A biopsy of the mass revealed a diagnosis of well-differentiated squamous cell carcinoma. On preoperative examination, the tumor was 90×40 mm in size and was suspected to have partially invaded the levator ani muscle and external sphincter. Since a preoperative cardiac evaluation indicated severe aortic stenosis, we performed transcatheter aortic valve implantation. A radical resection was then performed with general anesthesia. The skin and subcutaneous tissue defects were reconstructed with a posterior gluteal-thigh propeller flap, and a sigmoid colostomy was created. The patient had a good postoperative course and was transferred to a rehabilitation facility 28 days after the surgery. Epidermal cysts are a common benign tumor, and clinicians should keep in mind that these cysts can become malignant.

p53-Armed Oncolytic Virotherapy Improves Radiosensitivity in Soft-Tissue Sarcoma by Suppressing BCL-xL Expression.

Soft-tissue sarcoma (STS) is a heterogeneous group of rare tumors originating predominantly from the embryonic mesoderm. Despite the development of combined modalities including radiotherapy, STSs are often refractory to antitumor modalities, and novel strategies that improve the prognosis of STS patients are needed. We previously demonstrated the therapeutic potential of two telomerase-specific replication-competent oncolytic adenoviruses, OBP-301 and tumor suppressor p53-armed OBP-702, in human STS cells. Here, we demonstrate in vitro and in vivo antitumor effects of OBP-702 in combination with ionizing radiation against human STS cells (HT1080, NMS-2, SYO-1). OBP-702 synergistically promoted the antitumor effect of ionizing radiation in the STS cells by suppressing the expression of B-cell lymphoma-X large (BCL-xL) and enhancing ionizing radiation-induced apoptosis. The in vivo experiments demonstrated that this combination therapy significantly suppressed STS tumors' growth. Our results suggest that OBP-702 is a promising antitumor reagent for promoting the radiosensitivity of STS tumors.

Omental Abscess after Laparoscopic Proximal Gastrectomy Successfully Treated with Percutaneous Drainage.

We report the case details of a 65-year-old Japanese man with an omental abscess that was discovered 43 days after he underwent a laparoscopic proximal gastrectomy for gastric cancer. His chief complaint was mild abdominal pain that had persisted for several days. The abscess was diagnosed as a rare postoperative complication. We hesitated to perform a reoperation given the invasiveness of general anesthesia and surgery, plus the possibility of postoperative adhesions and because the patient's general condition was stable and he had only mild abdominal pain. Percutaneous drainage using a 10.2-F catheter was performed with the patient under conscious sedation and computed tomography-fluoroscopy guidance, with no complications. After the procedure, the size of the abscess cavity was remarkably reduced, and 23 days later the catheter was withdrawn.

[Novel Therapy Targeting the Cancer Microenvironment Using Near-Infrared Photoimmunotherapy Leading to Tumor Immune Activation].

Near-infrared photoimmunotherapy(NIR-PIT)is a novel cancer treatment modality that employs antibody-IRDye700DX (IR700)conjugates. Recently, the clinical application of NIR-PIT has received approval in Japan for patients with inoperable head and neck cancer, specifically targeting the human epidermal growth factor receptor(hEGFR). Furthermore, NIR-PIT extends beyond the scope of tumor antigens and can be employed to eliminate specific host cells that contribute to the creation of immune-permissive environments supporting tumor growth. One of the distinguishing features of NIR-PIT is its ability to selectively eliminate various cell types within the tumor microenvironment(TME)by specifically targeting distinct antigens. By employing podoplanin(PDPN)-targeted NIR-PIT, PDPN-expressing fibroblasts were selectively eradicated, resulting in the suppression of tumor progression and a notable extension of overall survival. Additionally, we investigated the efficacy of depleting myeloid-derived suppressor cells(MDSCs)using NIR-PIT. This approach led to the selective elimination of MDSCs within tumors, and remarkable abscopal effects were observed in bilateral tumor models. Hence, NIR-PIT holds immense promise for the treatment of diverse cancer types by precisely targeting tumor cells, fibroblasts, and immune cells.

Rare case of rectal carcinoid with synchronous primary carcinoid tumors of the lung misdiagnosed as lung metastases.

A 68-year-old woman was referred to our hospital for rectal surgery after a pathological diagnosis of rectal carcinoid with venous invasion following endoscopic submucosal dissection of a 5 mm-sized submucosal tumor in the lower rectum. Chest CT showed nodules in the left upper lobe and right lower lobe, but positron emission tomography and somatostatin receptor scintigraphy showed no hyperaccumulation in the lung nodules. CT-guided needle biopsy was performed on the nodular lesion in the left upper lobe, which showed focal growth of tumor cells with a high N/C ratio and positive synaptophysin, leading to a diagnosis of pulmonary metastasis of rectal carcinoid. Since the patient was asymptomatic and did not wish to undergo surgery or chemotherapy, she was followed up strictly with sufficient informed consent. Three years have passed since the diagnosis, and there is no tendency for the lung metastasis to increase, and no other new lesions have been observed. The disease had not progressed and remained stable. Therefore, immunohistological analysis of the lung biopsy specimen was performed again, which was positive for TTF-1 and negative for CDX2. Consequently, the diagnosis was changed to primary lung carcinoid tumors, and the patient remains under follow-up with no disease progression.

Surgical repair for a parahiatal hernia with an esophageal hiatal hernia: A case report and literature review.

INTRODUCTION AND IMPORTANCE: A parahiatal hernia (PH) is a rare diaphragmatic hernia (DH) adjacent to but separated from the esophageal hiatus. The surgical repair for PH needs primary suture closure or complicated hernioplasty and the addition of an anti-reflux procedure. This report describes a case of PH with a symptomatic esophageal hiatal hernia managed using three-dimensional (3D) laparoscopy. CASE PRESENTATION: A 65-year-old woman with back pain and breathlessness was referred to our hospital for a DH. Computed tomography showed a diaphragmatic defect on the left side of the esophageal hiatus. Upper gastrointestinal endoscopy and 24-hour esophageal impedance-pH monitoring showed a symptomatic esophageal hiatal hernia. Laparoscopic repair for both hernias was performed using 3D laparoscopy. The DH orifice was located in the left crus of the diaphragm, and it was separated from the esophageal hiatus. These findings showed that this DH was a PH. The PH was repaired with primary suturing, and a hiatoplasty was performed. Toupet fundoplication was performed with a 270° posterior wrap of the gastric fornix. The patient has remained asymptomatic a year after surgery without any complications. CLINICAL DISCUSSION: 3D laparoscopy provides significant advantages in surgeries requiring precise suturing. PH repairs require complex procedures, including mesh repair or suturing. Approximately 44 % of PH cases also necessitate fundoplication. 3D laparoscopy was useful for the present case. CONCLUSIONS: A rare PH and a symptomatic type 1 hiatal hernia were repaired with 3D laparoscopy, which is helpful for PH treatment in cases requiring complicated procedures.

Robot-assisted laparoscopic surgery for rectal cancer in a patient with a horseshoe kidney: A case report.

A 52-year-old, Japanese man presented to the hospital with a complaint of anal bleeding, and detailed examination resulted in a diagnosis of locally advanced rectal cancer. The patient underwent total neoadjuvant therapy followed by short-course radiation therapy and consolidation chemotherapy, which provided a partial response. After preoperative contrast-enhanced computed tomography showed a horseshoe kidney, robot-assisted, precise, laparoscopic, low anterior resection with D3 dissection and ileostomy construction was performed. The horseshoe renal isthmus was elevated surrounding the inferior mesenteric artery, and the left ureter and seminal vessels ran in front of the kidney. The hypogastric nerve traveled ventral to the horseshoe kidney. With robotic surgery, it was possible to perform more precise surgery while recognizing vascular and nerve anatomy in a rectal cancer patient with a horseshoe kidney due to good three-dimensional visibility and articulated forceps manipulation.

Role of robotic surgery as an element of Enhanced Recovery After Surgery protocol in patients undergoing pancreatoduodenectomy.

BACKGROUND: Although the current trend in pancreatoduodenectomy (PD) has shifted from open surgery to minimally invasive surgery (MIS), evidence on the role of MIS as an element of Enhanced Recovery After Surgery (ERAS) in PD is limited. This study aimed to investigate the effect of robotic surgery using the ERAS protocol on the outcomes of patients undergoing PD. METHODS: This retrospective study included 252 patients who underwent open PD (OPD) or robotic PD (RPD) managed using the ERAS protocol between January 2017 and March 2023. Outcomes stratified by the surgical approach were compared. Multivariable analyses were performed to evaluate the effect of ERAS items, including robotic surgery, on outcomes after PD. RESULTS: Of 252 patients, 202 (80.2%) underwent OPD, and 50 (19.2%) underwent RPD. Multivariable analyses demonstrated that perioperative management center support (odds ratio [OR], 2.85; 95% CI, 1.14-7.72; P = .025), robotic surgery (OR, 6.40; 95% CI, 1.94-26.1; P = .002), early solid intake (OR, 2.84; 95% CI, 1.46-5.63; P = .002), and early drain removal (OR, 3.77; 95% CI, 2.04-7.06; P < .001) were significant ERAS items related to early discharge after PD. CONCLUSION: Our study demonstrated that employing the ERAS protocol for OPD and RPD is feasible and safe. Moreover, our results suggested the role of robotic surgery as an element of the ERAS protocol for PD. A combination of ERAS protocols and MIS may be safe and feasible for accelerating postoperative recovery after PD.

Subtotal esophagectomy and concurrent reconstruction with free jejunal flap for primary esophageal cancer after pancreatoduodenectomy.

BACKGROUND: Pancreatoduodenectomy and subtotal esophagectomy are widely considered the most invasive and difficult surgical procedures in gastrointestinal surgery. Subtotal esophagectomy after pancreatoduodenectomy is expected to be extremely difficult due to complicated anatomical changes, and selecting an appropriate intestinal reconstruction method will also be a difficult task. Therefore, perhaps because the method is considered impossible, there have been few reports of subtotal esophagectomy after pancreatoduodenectomy. CASE PRESENTATION: A 73-year-old man with a history of pancreatoduodenectomy was diagnosed with superficial thoracic esophageal squamous cell carcinoma. Definitive chemoradiation therapy was recommended at another hospital; however, he visited our department to undergo surgery. We performed the robot-assisted thoracoscopic subtotal esophagectomy. There were some difficulties with the reconstruction: the gastric tube could not be used, the reconstruction was long, and the organs reconstructed in the previous surgery had to be preserved. However, the concurrent reconstruction was achieved with the help of a free jejunal flap and vascular reconstruction. All reconstructions from the previous surgery, including the remnant stomach, were preserved via regional abdominal lymph node dissection. After reconstruction, intravenous indocyanine green showed that circulation in the reconstructed intestines was preserved. On postoperative day 1, no recurrent nerve paralysis was observed during laryngoscopy. The patient could start oral intake smoothly 2 weeks after surgery and did not exhibit any postoperative complications related to the reconstruction. The patient was transferred to another hospital on postoperative day 21. CONCLUSIONS: Owing to the free jejunal flap interposition method, we safely performed one stage subtotal esophagectomy and concurrent reconstruction, preservation of the remnant stomach, and pancreaticobiliary reconstruction in patients with a history of pancreatoduodenectomy. We believe that this method is acceptable and useful for patients undergoing complicated reconstruction.

Epidural versus patient-controlled intravenous analgesia on pain relief and recovery after laparoscopic gastrectomy for gastric cancer: randomized clinical trial.

BACKGROUND: Epidural analgesia (EDA) is a main modality for postoperative pain relief in major open abdominal surgery within the Enhanced Recovery After Surgery protocol. However, it remains unclear whether EDA is an imperative modality in laparoscopic gastrectomy (LG). This study examined non-inferiority of patient-controlled intravenous analgesia (PCIA) to EDA in terms of postoperative pain and recovery in patients who underwent LG. METHODS: In this open-label, non-inferiority, parallel, individually randomized clinical trial, patients who underwent elective LG for gastric cancer were randomized 1:1 to receive either EDA or PCIA after surgery. The primary endpoint was pain score using the Numerical Rating Scale at rest 24 h after surgery, analysed both according to the intention-to-treat (ITT) principle and per protocol. The non-inferiority margin for pain score was set at 1. Secondary outcomes were postoperative parameters related to recovery and adverse events related to analgesia. RESULTS: Between 3 July 2017 and 29 September 2020, 132 patients were randomized to receive either EDA (n = 66) or PCIA (n = 66). After exclusions, 64 patients were included in the EDA group and 65 patients in the PCIA group for the ITT analysis. Pain score at rest 24 h after surgery was 1.94 (s.d. 2.07) in the EDA group and 2.63 (s.d. 1.76) in the PCIA group (P = 0.043). PCIA was not non-inferior to EDA for the primary endpoint (difference 0.69, one side 95% c.i. 1.25, P = 0.184) in ITT analysis. Postoperative parameters related to recovery were similar between groups. More EDA patients (21 (32.8%) versus 1 (1.5%), P < 0.001) developed postoperative hypotension as an adverse event. CONCLUSIONS: PCIA was not non-inferior to EDA in terms of early-phase pain relief after LG.Registration number: UMIN000027643 (https://www.umin.ac.jp/ctr/index-j.htm).

Ramucirumab in second­line advanced colorectal cancer therapy: A study on therapeutic outcomes and hepatic sinusoidal platelet aggregation.

The present study investigated the role of ramucirumab (RAM) in treating liver metastases (LMs) as a second-line or salvage treatment in patients with advanced CRC. Of the 36 patients, 21 (58%) received RAM plus folinic acid, fluorouracil and irinotecan (FOLFIRI) as second-line treatment, whereas 15 (42%) received it in a salvage setting. The median overall survival time was 23 months [95% confidence interval (CI), 12-34 months] for those in the second-line treatment group and 8 months (95% CI, 5-19 months) for those in the salvage treatment group. Of the 36 patients, 14 (39%) underwent surgical resection of LMs during chemotherapy. A total of 6 patients underwent surgical resection for LMs for the first time during second-line RAM plus FOLFIRI (RAM-LM); of the remaining 8 patients, 6 underwent resection of LMs during first-line bevacizumab (BEV)-based chemotherapy (BEV-LM). Immunohistochemical analysis of CD42b showed that the platelet aggregation score (CD42b score), which ranges from 0 (absence of deposition) to 3 (presence of linear deposition), tended to decrease with the increasing duration of treatment with both RAM and BEV. Although there was no significant difference in the mean duration of anti-VEGF antibody treatment between the BEV-LM and RAM-LM groups, the median CD42b score was higher in the RAM-LM group (median CD42b score, 3; range, 0-3) compared with that in the BEV-LM group (median CD42b score, 1; range, 0-3; P=0.01), suggesting that RAM induces a different degree of platelet aggregation in liver sinusoids compared to BEV.

A multi-center, prospective, clinical study to evaluate the anti-reflux efficacy of laparoscopic double-flap technique (lD-FLAP Study).

Background: Double-flap technique (DFT) is a reconstruction procedure after proximal gastrectomy (PG). We previously reported a multi-center, retrospective study in which the incidence of reflux esophagitis (RE) (Los Angeles Classification ≥Grade B [LA-B]) 1 year after surgery was 6.0%. There have been many reports, but all of them were retrospective. Thus, a multi-center, prospective study was conducted. Methods: Laparoscopic PG + DFT was performed for cT1N0 upper gastric cancer patients. The primary endpoint was the incidence of RE (≥LA-B) 1 year after surgery. The planned sample size was 40, based on an estimated incidence of 6.0% and an upper threshold of 20%. Results: Forty patients were recruited, and 39, excluding one with conversion to total gastrectomy, received protocol treatment. Anastomotic leakage (Clavien-Dindo ≥Grade III) was observed in one patient (2.6%). In 38 patients, excluding one case of postoperative mortality, RE (≥LA-B) was observed in two patients (5.3%) 1 year after surgery, and the upper limit of the 95% confidence interval was 17.3%, lower than the 20% threshold. Anastomotic stricture requiring dilatation was observed in two patients (5.3%). One year after surgery, body weight change was 88.9 ± 7.0%, and PNI <40 and CONUT ≥5, indicating malnutrition, were observed in only one patient (2.6%) each. In the quality of life survey using the PGSAS-45 questionnaire, the esophageal reflux subscale score was 1.4 ± 0.6, significantly better than the public data (2.0 ± 1.0; p = 0.001). Conclusion: Laparoscopic DFT showed anti-reflux efficacy. Taken together with the acceptable incidence of anastomotic stricture, DFT can be an option for reconstruction procedure after PG.

Functional remodeling of intraperitoneal macrophages by oncolytic adenovirus restores anti-tumor immunity for peritoneal metastasis of gastric cancer.

Intraperitoneal tumor-associated macrophages (TAMs) are involved in evading anti-tumor immunity and promoting the peritoneal metastasis (PM) of gastric cancer (GC). Oncolytic viruses are known to induce the activation of host anti-tumor immunity in addition to tumor lysis. This study investigated whether a wild-type p53-loading telomerase-specific oncolytic adenovirus (OBP-702) could elicit the remodeling of intraperitoneal macrophages and enhance the efficacy of immune therapy. Increased numbers of CD163 TAMs and few CD8+ lymphocytes were immunohistochemically observed in clinical samples with PM, which suggested that TAMs were associated with the suppression of anti-tumor immunity. OBP-702 induced immunogenic cell death and upregulated PD-L1 expression in human and murine GC cell lines. Intraperitoneal administration of OBP-702 increased recruitment of CD8+ lymphocytes into the PM via the functional remodeling of intraperitoneal macrophages from TAM toward a pro-inflammatory phenotype, resulting in significantly suppressed tumor growth for the in vivo model. Furthermore, the combination of intraperitoneal OBP-702 with anti-programmed cell death-1 antibody enhanced anti-tumor immunity and prolonged the survival of mice bearing PM. Intraperitoneal immunotherapy using OBP-702 restores anti-tumor immunity via the remodeling of intraperitoneal macrophages in addition to direct tumor lysis and cooperates with immune checkpoint inhibitors to suppress PM in GC.

Near-infrared Photoimmunotherapy Targeting Cancer-Associated Fibroblasts in Patient-Derived Xenografts Using a Humanized Anti-Fibroblast Activation Protein Antibody.

Esophageal cancer remains a highly aggressive malignancy with a poor prognosis, despite ongoing advancements in treatments such as immunotherapy. The tumor microenvironment, particularly cancer-associated fibroblasts (CAF), plays a crucial role in driving the aggressiveness of esophageal cancer. In a previous study utilizing human-derived xenograft models, we successfully developed a novel cancer treatment that targeted CAFs with near-infrared photoimmunotherapy (NIR-PIT), as an adjuvant therapy. In this study, we sought to translate our findings toward clinical practice by employing patient-derived xenograft (PDX) models and utilizing humanized mAbs, specifically sibrotuzumab, which is an antihuman fibroblast activation protein (FAP) Ab and already being investigated in clinical trials as monotherapy. PDX models derived from patients with esophageal cancer were effectively established, preserving the expression of key biomarkers such as EGFR and FAP, as observed in primary tumors. The application of FAP-targeted NIR-PIT using sibrotuzumab, conjugated with the photosensitizer IR700DX, exhibited precise binding and selective elimination of FAP-expressing fibroblasts in vitro. Notably, in our in vivo investigations using both cell line-derived xenograft and PDX models, FAP-targeted NIR-PIT led to significant inhibition of tumor progression compared with control groups, all without inducing adverse events such as weight loss. Immunohistologic assessments revealed a substantial reduction in CAFs exclusively within the tumor microenvironment of both models, further supporting the efficacy of our approach. Thus, our study demonstrates the potential of CAF-targeted NIR-PIT employing sibrotuzumab as a promising therapeutic avenue for the clinical treatment of patients with esophageal cancer.