Long-term survival without recurrence after surgery for gastric yolk sac tumor-like carcinoma: a case report

Background Gastric yolk sac tumor (YST)-like carcinoma is extremely rare, and its prognosis is poor, because most patients have widespread metastases at the time of diagnosis. We report a case of gastric YST-like carcinoma with an adenocarcinoma component without metastases in which curative resection was performed. Case presentation A 77-year-old man complaining of melena and dizziness due to anemia was diagnosed with poorly differentiated adenocarcinoma in the gastric cardia, with a benign ulcer in the gastric body. He underwent total gastrectomy with D2 lymph node dissection for the tumor. Histological examination of the resected specimens revealed a mixture of reticular and glandular neoplastic components morphologically. In the reticular area, an endodermal sinus pattern and some Schiller-Duval bodies were confirmed. Gastric YST-like carcinoma with adenocarcinoma components, T2N0M0 Stage IB, was diagnosed. Immunohistochemical analysis showed that the YST was positive for carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP) and p53. In contrast, the adenocarcinoma was positive for p53 and negative for CEA and AFP. The patient remained healthy as of 7 years postoperatively, with no recurrence. Conclusions Routine medical examinations or endoscopic examinations for accidental symptom may be helpful for early diagnosis and good prognosis for gastric YST-like carcinoma, although the prognosis is generally poor

Targeting neutrophil extracellular traps with thrombomodulin prevents pancreatic cancer metastasis

Surgery is the only curative treatment option for pancreatic cancer, but patients often develop postoperative recurrence. Surgical invasiveness might be involved in the mechanism of recurrence. The associations among inflammation caused by surgery, neutrophils, and cancer metastasis were investigated. At first, neutrophil extracellular traps (NETs) were examined in clinical specimens, and NETs were observed around metastatic tumors. To explore how NETs were induced, neutrophils were cultured with pancreatic cancer or in cancer-conditioned medium. Neutrophils formed NETs when they were cultured with pancreatic cancer or even its conditioned medium. The effects of NETs on cancer cells were further investigated in vitro and in vivo. NETs induced the epithelial to mesenchymal transition in cancer cells and thereby promoted their migration and invasion. HMGB1 derived from NETs appeared to potentiate the malignancy of cancer cells. In a mouse model of liver metastasis with inflammation, NETs participated in the metastatic process by enhancing extravasation. Interestingly, thrombomodulin degraded HMGB1 and consequently inhibited the induction of NETs, thereby preventing pancreatic cancer metastasis to the liver. In conclusion, NETs interact reciprocally with pancreatic cancer cells, which play a pivotal role in inflammation-associated metastasis. Targeting NETs with thrombomodulin can be a novel strategy to improve the surgical outcome of pancreatic cancer patients

Oncolytic virus-mediated p53 overexpression promotes immunogenic cell death and efficacy of PD-1 blockade in pancreatic cancer

Immune checkpoint inhibitors, including anti-programmed cell death 1 (PD-1) antibody, provide improved clinical outcome in certain cancers. However, pancreatic ductal adeno-carcinoma (PDAC) is refractory to PD-1 blockade therapy due to poor immune response. Oncolytic virotherapy is a novel approach for inducing immunogenic cell death (ICD). We demonstrated the therapeutic potential of p53-expressing telo-merase-specific oncolytic adenovirus OBP-702 to induce ICD and anti-tumor immune responses in human PDAC cells with different p53 status (Capan-2, PK-59, PK-45H, Capan-1, MIA PaCa-2, BxPC-3) and murine PDAC cells (PAN02). OBP-702 significantly enhanced ICD with secretion of extracel-lular adenosine triphosphate and high-mobility group box pro-tein B1 by inducing p53-mediated apoptosis and autophagy. OBP-702 significantly promoted the tumor infiltration of CD8+ T cells and the anti-tumor efficacy of PD-1 blockade in a subcutaneous PAN02 syngeneic tumor model. Our results suggest that oncolytic adenovirus-mediated p53 overexpres-sion augments ICD and the efficacy of PD-1 blockade therapy against cold PDAC tumors. Further in vivo experiments would be warranted to evaluate the survival benefit of tumor-bearing mice in combination therapy with OBP-702 and PD-1 blockade

RNA editing facilitates the enhanced production of neoantigens during the simultaneous administration of oxaliplatin and radiotherapy in colorectal cancer

Most cases of colorectal cancers (CRCs) are microsatellite stable (MSS), which frequently demonstrate lower response rates to immune checkpoint inhibitors (ICIs). RNA editing produces neoantigens by altering amino acid sequences. In this study, RNA editing was induced artificially by chemoradiation therapy (CRT) to generate neoantigens in MSS CRCs. Altogether, 543 CRC specimens were systematically analyzed, and the expression pattern of ADAR1 was investigated. In vitro and in vivo experiments were also performed. The RNA editing enzyme ADAR1 was upregulated in microsatellite instability-high CRCs, leading to their high affinity for ICIs. Although ADAR1 expression was low in MSS CRC, CRT including oxaliplatin (OX) treatment upregulated RNA editing levels by inducing ADAR1. Immunohistochemistry analyses showed the upregulation of ADAR1 in patients with CRC treated with CAPDX (capecitabine +OX) radiation therapy relative to ADAR1 expression in patients with CRC treated only by surgery (p <0.001). Compared with other regimens, CRT with OX effectively induced RNA editing in MSS CRC cell lines (HT29 and Caco2, p <0.001) via the induction of type 1 interferon-triggered ADAR1 expression. CRT with OX promoted the RNA editing of cyclin I, a neoantigen candidate. Neoantigens can be artificially induced by RNA editing via an OX-CRT regimen. CRT can promote proteomic diversity via RNA editing

腎摘除術後の対側腎の代償性肥大と腎機能の変移

腎摘除術後の対側腎の体積と腎機能の変移を検討した.対象は腎細胞癌で腎摘除術を受け, 対側腎に明らかな異常がなく, 当院で少なくとも2年以上経過観察している25例であった.25例中12例で毎年CT検査を受けていた.腎の体積は造影CT上の腎の3方向の径を測定し楕円体体積の公式に当てはめて求めた。対側腎の体積は術後3年目まで増加し, 術前体積(100%)に比べて2～7年後の平均最終体積は120%であった.対側腎の腎摘前の体積と術後の最終体積の間に有意な相関はなかったが, 術前に小さい腎は腎摘後の最終体積比率が大きい傾向にあった.血清クレアチニン値は術後1年目に有意に増加したが, 1年目の値に比べてその後数年の経過で有意に低下した.つまり, 代償性腎肥大と腎機能の改善は術後数年以内に完成されるものの, 腎肥大に比べて血清クレアチニン値の改善は遅れた.この理由として, 術後早期の腎血漿流量の増加に伴って代償性腎肥大は起こるが, 糸球体濾過率の上昇は2-一一3年遅れるため, 上昇していた血清クレアチニン値の低下も遅れたことが考えられた.We studied the changes in the serum creatinine level and the volume of the remaining kidney following nephrectomy using contrast-enhanced compounded tomogram (CT) scans. Twenty-five patients undergoing nephrectomy for renal cell carcinoma without obvious disease in the remaining kidney were carefully followed for a period of at least two years at our hospital. Twelve patients received follow-up CT scans each year after nephrectomy. The ellipsoid volume of the kidney was calculated by measuring the 3-dimensional size on CT scans. The mean relative volume (%) of the remaining kidney increased up to year 3 postoperatively, and the final mean relative volume at varying periods from years 2 to 7 was 120%. Kidneys that were smaller prior to nephrectomy showed a tendency to have a larger final relative volume after nephrectomy, although there was no significant correlation between the kidney volume prior to nephrectomy and at final measurement. The mean serum creatinine level was significantly increased at one year after nephrectomy, but it decreased significantly over time. Therefore, both compensatory renal hypertrophy and improved renal function seemed to be established within several years after nephrectomy. However, the improvement of serum creatinine was delayed compared with the increase of kidney volume. That is, renal plasma flow might be increased early by compensatory renal hypertrophy, followed within a few years by an increase in glomerular filtration and a decrease of serum creatinine

Accreditation as a qualified surgeon improves surgical outcomes in laparoscopic distal gastrectomy

Purpose: The Endoscopic Surgical Skill Quantification System for qualified surgeons (QSs) was introduced in Japan to improve surgical outcomes. This study reviewed the surgical outcomes after initial experience performing laparoscopic distal gastrectomy (LDG) and evaluated the improvement in surgical outcomes following accreditation as a QS. Methods: Eighty-seven consecutive patients who underwent LDG for gastric cancer by a single surgeon were enrolled in this study. The cumulative sum method was used to analyze the learning curve for LDG. The surgical outcomes were evaluated according to the two phases of the learning curve (learning period vs. mastery period) and accreditation (non-QS period vs. QS period). Results: The learning period for LDG was 48 cases. Accreditation was approved at the 67th case. The operation time and estimated blood loss were significantly reduced in the QS period compared to the non-QS period (230 vs. 270 min, p Conclusions: Experience performing approximately 50 cases is required to reach proficiency in LDG. After receiving accreditation as a QS, the surgical outcomes, including the complication rate, were improved