The tumor cell-intrinsic cGAS-STING pathway is associated with the high density of CD8+ T cells after chemotherapy in esophageal squamous cell carcinoma

BACKGROUND

Chemotherapy has the potential to induce CD8+ T-cell infiltration in the tumor microenvironment (TME) and activate the anti-tumor immune response in several cancers including esophageal squamous cell carcinoma (ESCC). The tumor cell-intrinsic cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been known as a critical component for regulating immune cell activation in the TME. However, its effect on the infiltration of immune cells induced by chemotherapy in the ESCC TME has not been investigated.

METHODS

We examined the effect of the tumor-cell intrinsic cGAS-STING pathway on the infiltration of CD8+ T cells induced by chemotherapy in ESCC using ESCC cell lines and surgically resected ESCC specimens from patients who received neoadjuvant chemotherapy (NAC).

RESULTS

We found that chemotherapeutic agents, including 5-fluorouracil (5-FU) and cisplatin (CDDP), activated the cGAS-STING pathway, consequently inducing the expression of type I interferon and T-cell-attracting chemokines in ESCC cells. Moreover, the tumor cell-intrinsic expression of cGAS-STING was significantly and positively associated with the density of CD8+ T cells in ESCC after NAC. However, the tumor cell-intrinsic expression of cGAS-STING did not significantly impact clinical outcomes in patients with ESCC after NAC.

CONCLUSION

Our findings suggest that the tumor cell-intrinsic cGAS-STING pathway might contribute to chemotherapy-induced immune cell activation in the ESCC TME.

[A Case of Perforation of the Duodenum during Chemotherapy with Ramucirumab plus Nab-Paclitaxel for Advanced Gastric Cancer]

A 70-year-old male patient was diagnosed with advanced gastric cancer with para-aortic lymph node metastasis. After diagnostic laparoscopy, the patient received 2 courses of neoadjuvant chemotherapy. Subsequently, distal gastrectomy, D2 plus para-aortic lymph node dissection, and Roux-en-Y reconstruction were performed. An enlarged lymph node(No. 16b2)was identified during surgery. The histopathological diagnosis revealed ypT4b, ypN3b, cM1(LYM; No. 16), Stage ⅣB. Chemotherapy with ramucirumab plus nab-paclitaxel was administered at 6 weeks postoperatively. However, after 2 courses of chemotherapy, the patient developed an abscess discharge from the wound, which was confirmed by an abdominal CT scan and diagnosed as an intra-abdominal abscess derived from duodenal perforation. The abscess was drained percutaneously. Subsequently, chemotherapy with nab-paclitaxel, nivolumab, and trifluridine/tipiracil hydrochloride was administered. After the appearance of brain metastases, the treatment was shifted to palliative care. The patient died 2 years and 7 months later from the primary disease.

A Potential Biomarker of Dynamic Change in Peripheral CD45RA-CD27+CD127+ Central Memory T Cells for Anti-PD-1 Therapy in Patients with Esophageal Squamous Cell Carcinoma

In order to develop a biomarker predicting the efficacy of treatments for patients with esophageal squamous cell carcinoma (ESCC), we evaluated the subpopulation of T cells in ESCC patients treated with chemotherapy (CT), chemoradiotherapy (CRT), and nivolumab therapy (NT). Fifty-five ESCC patients were enrolled in this study, and peripheral blood samples were collected before and after CT or CRT and during NT. Frequencies of memory, differentiated, and exhausted T cells were evaluated using flow cytometry among cStages, treatment strategies, pathological responses of CT/CRT, and during NT. The frequencies of PD-1⁺ or TIM-3⁺CD4⁺ T cells were significantly higher in patients with cStage IV. PD-1⁺CD4⁺ and TIM-3⁺CD8⁺ T-cell populations were significantly higher in patients treated with CRT but were not associated with treatment response. The frequencies of both CD4⁺ and CD8⁺ CD45RA^-CD27⁺CD127⁺ central memory T cells (T_CM) were significantly decreased during the course of NT in the progressive disease group. Taken together, the alteration in frequency of CD45RA^-CD27⁺CD127⁺ T_CM during NT may be a biomarker to predict its therapeutic response in ESCC patients.

Clinical usefulness of ramucirumab plus paclitaxel for unresectable and recurrent gastric cancer

Introduction Recently in Japan, Ramucirumab (RAM) became the first anti-angiogenic agent to be approved for second-line treatment of gastric cancer. In the present study, we aimed to evaluate the efficacy and safety of RAM plus paclitaxel (PTX) in patients with unresectable and recurrent gastric cancer in our institution.Patients and Methods The subjects were 11 patients with unresectable and recurrent gastric cancer who received RAM plus PTX as a second- or later-line treatment at our hospital between June 2015 and September 2017, after the failure of previously-attempted treatments. We assessed the efficacy and safety of RAM plus PTX, and also compared them between patients aged <75 years (n=6) and those aged ≥75 (n=5), by performing a retrospective analysis based on the data obtained from daily clinical practice for gastric cancer treatment.Results Objective tumor response was observed in one of the 11 patients (9.1%) with partial response, and disease control was seen in the remaining 10 (90.9%). The median overall survival (OS) and progression-free survival (PFS) of the patients were 20.8 months (95% CI 7.8-NA (not applicable)) and 11.3 months (95% CI 6.5-NA), respectively. There were no serious adverse events. The median OS for the <75 years group and ≥75 years group was NA (due to short follow-up period) and 20.8 months (p = 0.336), respectively, and their respective median PFS rates were 9.4 and 11.3 months (p = 0.492). The difference of rate of adverse events was not significant between the two age groups in the present study, though the number of adverse events was not sufficient.Conclusion The results of the present study suggest that the combination chemotherapy of RAM and PTX was effective in unresectable and recurrent gastric cancer patients as a second- or later-line therapy, and has been shown to be safe and feasible in elderly patients.

[Laparoscopic Endoscopic Cooperative Surgery(LECS)for Duodenal Tumors]

We report 2 cases of superficial non-ampullary duodenal tumor resected using laparoscopic endoscopic cooperative surgery( LECS). A man in his5 0's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the anal side of the papilla of Vater that measured 5 mm. We performed LECS, and pathologic examination revealed tubular adenoma with no tumor cellsat the edge of the specimen. A man in his 80's underwent screening esophagogastroduodenoscopy. Endoscopy revealed a 0-Ⅱc lesion at the posterior wall above the papilla of Vater that measured 10 mm. The biopsy showed a well-differentiated adenocarcinoma. We performed LECS, and the pathological examination revealed a tubular adenocarcinoma in the mucosal layer with no carcinoma cells at the edge of the specimen. As the treatment strategy for superficial duodenal tumors has not established yet, further accumulation of cases and investigation are necessary.

[A Case of Rectal Colon Cancer with Paraneoplastic Cerebellar Degeneration]

A case complicated with colorectal and prostate cancers in paraneoplastic(subacute)cerebellar degeneration(PCD)is extremely rare. We report a retrospective case of rectal carcinoma with paraneoplastic cerebellar degeneration. A 79-year-old man with Parkinson's disease was unable to walk because of paralysis. Brain MRI showed cerebellar atrophy. He was admitted to our hospital for anal bleeding and was diagnosed with colon cancer. An associated diagnosis of PCD was made. After resection, his paralysis and dysarthria were resolved to the extent of beingable to walk and speak fluently. Brain MP-RAGE showed no findings suggestive of metastasis or atrophy. He was treated surgically, which resulted in a transient improvement in PCD symptoms. Per blood testing, cytokines IL-6 and IL-10 were lower postoperatively. Immunosuppressive levels of myeloid- derived suppressor cells(MDSCs)were lower compared with the preoperative values. Thus, innate immunocompetence and resolution of paralysis followed the surgical intervention.

Neuroendocrine tumor of the extrahepatic bile duct: A case report

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Neuroendocrine tumors of the extrahepatic bile ducts are extremely rare neoplasms.

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They most commonly occur in young females and usually present with painless jaundice.

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Preoperative diagnosis is difficult because the findings are similar to other biliary malignancies.

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Surgical resection is considered to be the only curative treatment.

Introduction

Neuroendocrine tumors (NETs) of the extrahepatic bile ducts are extremely rare neoplasms arising from endocrine cells and have variable malignant potential. They most commonly occur in young females and usually present with painless jaundice.

Presentation of case

Here we present the case of an asymptomatic 57-year-old woman with NET of the common bile duct that was incidentally discovered on abdominal ultrasound during a medical examination. She was admitted to our hospital with a diagnosis of hepatic hilar tumor. Computed tomography revealed the tumor surrounding the hepatic hilum and duodenum. Magnetic resonance cholangiopancreatography revealed a filling defect of the common bile duct with morphology suggestive of external compression. Endoscopic ultrasound confirmed a submucosal tumor of the duodenal bulb measuring 30 × 20 mm in size. The patient qualified for surgery with a preoperative diagnosis of submucosal tumor of the duodenal bulb. Intraoperative examination revealed that the tumor location involved the common bile duct and/or cystic duct with no signs of invasion to other organs or metastatic lymph nodes. Excision of the biliary ducts and tumor was followed by Roux-en-Y anastomosis. Histological results showed NET grade 1.

Discussion

Preoperative diagnosis of NETs is difficult because of their rarity. A definitive diagnosis is usually established intraoperatively or after histopathological evaluation.

Conclusion

For these tumors, surgical resection is currently the only treatment modality for achieving a potentially curative effect and prolonged disease-free survival.

Pseudocirrhosis caused by regorafenib in an advanced rectal cancer patient with multiple liver metastases

A 70-year-old man who was diagnosed with unresectable advanced rectal cancer with multiple liver metastases, received oxaliplatin-based treatment with bevacizumab as first-line chemotherapy and irinotecan-based treatment with bevacizumab as second-line chemotherapy for a total of 17 months. The patient was treated with regorafenib (160 mg/day for 3 weeks) as third-line chemotherapy. Following completion of one course of regorafenib treatment, the patient complained of abdominal distension. Computed tomography (CT) examination identified liver atrophy and massive ascites, while no such symptoms were observed prior to the regorafenib treatment. Blood testing revealed increases in the aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels. The patient was admitted to the Aizu Medical Center (Aizuwakamatsu, Japan). Approximately 2,000 ml of ascitic fluid were aspirated daily for 1 week by abdominal puncture. The patient was administered oral diuretics, including 20 mg/day of furosemide and 25 mg/day of spironolactone. Albumin was administered to correct the albumin deficit. The levels of AST, ALT and ALP were decreased from the peak value reported on admission and the patient was discharged from our hospital 16 days following treatment initiation. The CT examination after 1 month revealed that the volume of the liver had been restored and the ascites had disappeared. Furthermore, almost all the liver metastases were reduced in size. The carcinoembryonic antigen level, which was elevated prior to regorafenib treatment, also decreased to normal.