[Three Cases of Appendiceal Goblet Cell Adenocarcinoma in Our Institution].

Appendiceal goblet cell adenocarcinoma(AGCA)is a newly designated pathological term adopted in the 5th edition of the WHO classification. It is synonymous with goblet cell carcinoid, which was previously categorized as a part of appendiceal carcinoid. However, since 2018, it has been classified as a subtype of adenocarcinoma. We have experienced 3 cases of this relatively rare tumor, of which 2 were initially diagnosed with acute appendicitis and were diagnosed with AGCA by pathological examination after an emergency appendectomy. Each of them underwent additional ileocolic resection with lymph node dissection as the second surgery. In the 3rd case, an appendiceal tumor was detected during preoperative examinations for an ovarian tumor. Staging laparoscopy revealed comorbid peritoneal dissemination, and only the appendix and right ovary were removed in the consecutive surgery. The ovarian tumor was pathologically diagnosed as a metastasis of AGCA. In this case, the introduction of oxaliplatin-based systemic chemotherapy after surgery achieved a complete response after more than 2 years. Although no recurrence has been observed in all 3 cases to date, AGCA is considered highly malignant compared to conventional appendiceal carcinoids. Therefore, it is crucial to practice multidisciplinary treatments, including sufficient radical surgery based on a precise diagnosis of AGCA, as is performed for advanced colorectal cancer.

Helicobacter pylori-Negative Advanced Gastric Cancer Arising from the Gastric Mucosa without Inflammation, Atrophy, or Intestinal Metaplasia.

Gastric cancer is strongly associated with atrophic gastritis associated with Helicobacter pylori infection. The eradication of H. pylori has been reported to improve inflammation of the gastric mucosa, atrophy, and intestinal metaplasia and has also been shown to inhibit the development and growth of gastric cancer. Advanced gastric cancer from H. pylori-negative mucosa without inflammation, atrophy, or intestinal epithelialization is rarely found. We report on two cases of advanced gastric cancer without endoscopic evidence of gastric mucosal atrophy. One case was in the gastric angle 9 years after H. pylori eradication and the other case was in the pylorus of an uninfected stomach. Although gastric cancer is strongly associated with atrophic gastritis caused by H. pylori infection, postoperative histopathological examination of the stomach in both cases showed no inflammation, atrophy, or intestinal metaplasia. Poorly differentiated adenocarcinomas were confirmed at the microscopic level, and both cases were determined to be type 4 using the Borrmann classification. There is a body of evidence showing that H. pylori infection can cause gastric cancer and is the most prevalent infection-induced cancer in the world. The 2 cases here displayed different carcinogenesis than gastric mucosal atrophy caused by H. pylori infection. With the spread of H. pylori eradication treatments and an increasing number of uninfected patients, these case reports can contribute to future strategies for the diagnosis of gastric cancer.

[Three Cases of Colon Medullary Carcinoma in Our Institution].

Medullary carcinoma of the colorectum is a relatively new histological subtype that was first described in the eighth edition of the Japanese classification of colorectal, appendiceal, and anal carcinoma. In our institution, only 3 cases of medullary carcinoma have been diagnosed since 2013. Case #1 was a 93-year-old woman with type 1 ascending colon cancer; she received a right hemicolectomy. The tumor invaded the subserosal layer, but no lymph nodal metastasis was observed. Case #2 was a 91-year-old woman with obstructive ascending colon cancer. After intracolonic decompression using the transnasal ileus tube, she received a right hemicolectomy. This tumor also extended into the subserosal layer without lymph nodal metastasis. Case #3 was a 65-year-old woman with a family history of cancers; she received a right hemicolectomy for cecal cancer with an aberrant elevation of serum tumor markers such as CEA and CA19-9. The tumor invaded the subserosal layer with regional lymph nodal metastases. Notably, these 3 cases were females who had right-sided tumors and all showed diminished expressions of MLH1 and PMS2 mismatch repair-associated genes, together with epidemiological characteristics of medullary carcinoma. Herein, we report their pathological features along with the corresponding literature review.

False-Positive Cases of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomographic Scans in Metastasis of Esophageal Cancer.

Of 129 esophagectomies at our institute from June 2010 to March 2015, we experienced three preoperative positron emission tomography-computed tomographic (PET/CT) false positives. Bone metastasis was originally suspected in 2 cases, but they were later found to be bone metastasis negative after a preoperative bone biopsy and clinical course observation. The other cases suspected of mediastinal lymph node metastasis were diagnosed as inflammatory lymphadenopathy by a pathological examination of the removed lymph nodes. Conducting a PET/CT is useful when diagnosing esophageal cancer metastasis, but we need to be aware of the possibility of false positives. Therapeutic decisions should be made based on appropriate and accurate diagnoses, with pathological diagnosis actively introduced if necessary.

Feasibility of oral administration of S-1 as adjuvant chemotherapy in gastric cancer: 4-week S-1 administration followed by 2-week rest vs. 2-week administration followed by 1-week rest.

In 2006, the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) demonstrated that S-1 is an effective adjuvant therapy for gastric cancer. Following that study, S-1 has been used as the standard adjuvant therapy for gastric cancer in Japan. However, the 1-year completion rate was only 65.8% in the ACTS-GC study and feasibility remains a critical issue. We conducted a study to evaluate the feasibility of 2 weekly administration regimens of S-1 as adjuvant chemotherapy in gastric cancer. The criteria for eligibility included histologically proven stage II (excluding T1), IIIA or IIIB gastric cancer with D2 lymph-node dissection. The patients were randomly assigned to either arm A (S-1 administration for 4 weeks followed by 2 weeks of rest) or arm B (S-1 administration for 2 weeks followed by 1 week of rest). In each arm, treatment was continued for 12 months unless recurrence or severe adverse events were observed. The primary endpoint was feasibility (protocol treatment completion rate). The secondary endpoints were safety, relapse-free survival and overall survival. A total of 47 patients were assigned to arms A or B between May, 2008 and February, 2010. During the first interim analysis, the protocol treatment completion rates in arms A and B were 83 and 100%, respectively at 6 months and 49 and 89%, respectively, at 12 months (P=0.0046). Therefore, S-1 administration for 2 weeks followed by 1 week rest was more feasible as adjuvant chemotherapy in gastric cancer. Grade 3 adverse events in arm A included fatigue (8.0%), anorexia (8.0%), nausea (4.0%), vomiting (4.0%) and hand-foot syndrome (4.0%), whereas none were observed in arm B. There were no reported grade 4 adverse events in either arm. In conclusion, the 2-week S-1 administration followed by 1-week rest regimen appears to be a more feasible oral administration regimen for S-1 as adjuvant chemotherapy in gastric cancer.

Detection of serum MMPs in tumor-bearing hamsters.

BACKGROUND/PURPOSE: Matrix metalloproteinases (MMPs) have been implicated as playing an important role in cancer invasion and metastasis. MMPs have been identified in various malignancies, including pancreatic duct adenocarcinomas. METHODS: We investigated the circulating level of MMP-2 and MMP-9 in sera from Syrian golden hamsters into which hamster pancreatic duct adenocarcinoma tissues had been transplanted subcutaneously (HPDt hamsters). Northern blot analysis and gelatin zymographic analysis were performed to detect the expression of MMPs and that of tissue inhibitors of metalloproteinases (TIMPs) in HPDt hamsters. RESULTS: Northern analysis revealed overexpression of MMP-2, MMP-9, and TIMP-2 mRNAs in subcutaneous tumors of HPDt hamsters as compared with normal pancreatic tissue. Sera from HPDt hamsters possessed significantly higher levels of serum MMP-2 and MMP-9 than control sera, as determined by gelatin zymographic analysis, and there was a significant correlation between tumor growth and serum MMP levels. CONCLUSIONS: These results indicate that overexpression of MMP mRNAs is involved in the progression of pancreatic duct adenocarcinomas, and that MMP protein expression in hamster sera is associated with the presence of pancreatic duct adenocarcinoma cells. The findings also suggest that serum MMPs could be useful markers for monitoring patients with pancreatic duct adenocarcinomas.