[Basics and Clinics of Cancer-Associated Venous Thromboembolism].

Cancer patients, especially active cancer patients have high risk of cancer-associated venous thromboembolism(VTE). Virchow's triad, hyper-coagulability, endothelial cell damage, and blood stasis are often found during cancer treatment. Tissue factor expressed on tumor cells activate coagulation, and decrease in antithrombotic activity by topical inflammation and platelet activation increase the risk of VTE. The risk of VTE is further enhanced by surgical intervention and chemotherapy. Anticoagulation is the most important treatment, however warfarin is not suitable for active cancer patients due to drug- drug interaction and gastrointestinal toxicity. In the Western countries, low molecular weight heparin (LMWH) is the standard choice for cancer-associated VTE. During anticoagulation, risk of recurrence of VTE and major bleeding is very high. Recently, direct oral anticoagulant(DOAC)has been introduced and widely used in Japan after the evidence of DOACs in cancer patients. Gastrointestinal bleeding is one of the frequent adverse events during DOAC treatment. Drug-drug interaction such as P-glycoprotein and CYP3A4 must be considered for safety treatment.

[Cross-Functional Project of Using Information-Sharing Tool for Metastatic Colorectal Cancer Patients in University Hospital].

Treatment for late-stage cancer patients should be discussed depending on the patients' will, however it is not sometimes fully discussed in our daily practice. Based on this background, the information-sharing tool for metastatic colorectal cancer patients, who are refractory to first-line and second-line chemotherapy and/or who are given a year to live, has been introduced in our university hospital since November 2019. To evaluate the utility of this tool, the influence of the tools on the outcome of the patients was evaluated. Regarding the comparison between the patients before and after the introduction of the information-sharing tool, the period between the day of the consent to the DNAR between the day of the death is longer in the patients after the introduction than those before the introduction(median 43 vs 6 days, p=0.025). The introduction of the information-sharing tool can provide the metastatic colorectal cancer patients with more opportunities to discuss how to spend the rest of their lives and with longer time at the place where they want to stay.

Evaluation of appropriate follow-up after curative surgery for patients with colorectal cancer using time to recurrence and survival after recurrence: a retrospective multicenter study.

INTRODUCTION: The follow-up schedule for colorectal cancer patients after curative surgery is inconsistent among the guidelines. Evaluation of time to recurrence (TTR) and survival after recurrence (SAR) may provide evidence for appropriate follow-up. METHODS: We assessed 3039 colon cancer (CC) and 1953 rectal cancer (RC) patients who underwent curative surgery between 2007 and 2008. We evaluated the pre- and post-recurrent clinicopathological factors associated with TTR and SAR in each stage of CC and RC. RESULTS: The recurrence rates of stages I, II, and III were 1.2%, 13.1%, and 26.3%, respectively, for CC, and 8.4%, 20.0%, and 30.4%, respectively, for RC. In CC patients, high carcinoembryonic antigen (CEA) level and lymphovascular invasion were independent predictors of short TTR. In RC patients, metastatic factors (liver metastasis in stage III) and venous invasion (stage III) were independent predictors of short TTR. The prognostic factors of SAR were age (stage II CC and stage III RC), female gender (stage III RC), high CEA level (stage II RC), histological type (stage III CRC), nodal status (stage III CC), recurrence within 1 year (stage III RC), M1b recurrence (stage II CRC), local recurrence (stage II CC), and no surgical resection after recurrence (stage II and III CRC). CONCLUSIONS: The follow-up schedule for stage I should be different from that for the other stages. We recommend that intensive follow-up is appropriate in stage III CC patients with undifferentiated adenocarcinoma or N2 nodal status, stage II RC patients with high preoperative CEA level, and stage III RC patients.

[Two Resected Cases of Non-Isolated Splenic Metastasis of Colon Cancer].

We report 2 resected cases of patients with non-isolated splenic metastasis of colon cancer. Case 1: A 67-year-old man who underwent partial transverse colectomy and partial hepatectomy for transverse colon cancer and liver metastasis. Approximately 18 months after the operation, splenectomy and partial hepatectomy were performed for metastasis to the spleen and liver. After partial hepatectomy for another recurrence, no signs of new recurrence have been observed for 42 months after splenectomy. Case 2: A 53-year-old woman who presented with bloating. CT and MRI scans revealed masses of the ileocecum, both ovaries, and spleen. We performed right hemicolectomy, total hysterectomy, bilateral salpingo-oophorectomy, pelvic lymphadenectomy, para-aortic lymphadenectomy, omentectomy, and splenectomy. Histological findings showed cecal cancer metastasizing to the bilateral ovaries and spleen. Metastatic splenic tumor is relatively rare(0.3-7.3%). Splenectomy was reported to be an effective treatment modality for isolated splenic metastasis, while that for non-isolated metastasis is uncertain. Surgical resection should be considered even in non-isolated splenic metastasis cases because of the evidence of long-term survival in case 1.

[A Resected Case of Castleman's Disease That Was Difficult to Diagnose Preoperatively].

A 70-year-old man was referred to our hospital and admitted after abdominal computed tomography(CT)examination revealed a tumor in the retroperitoneum. The specific blood test findings were poor, and surveillance CT demonstrated a wellcircumscribed, enhanced mass measuring 40mm with calcification behind the horizontal portion of the duodenum. The tumor presented with a slightly high signal in low signal, T2 in T1, and it showed a diffusion decrease in DWI; the simple abdominal MRIrevealed heterogeneous accumulation of SUVmax 3.0 only for the lesion in FDG/PET-CT. Specific findings did not lead to a diagnosis, although EUS-FNA lower aspiration biopsy cytology was performed. Laparoscopic tumorectomy was performed to help determine the treatment strategy. Histopathological examination indicated that the tumor was composed of multiple lymph follicles with concentric layers of mantle zone cells, showing an onion skin-like lesion and atrophic germinal centers. The germinal centers had penetrating arterioles with hyalinized vessel walls, and Castleman's disease(hyaline vascular type)was therefore diagnosed. In this case, it was difficult to diagnose Castleman's disease before surgery. Surgical excision is a diagnostic as well as a curative method for management of this disease.

[Pathological Complete Response in a Case of Advanced Esophageal Cancer with Widespread Lymph Node Metastases Treated Using Preoperative Chemotherapy with Docetaxel, Cisplatin, and 5-FU(DCF therapy)].

The patient was a 66-year-old woman, who was diagnosed with cT3N3M0, cStage III esophageal cancer with widespread lymph node metastases in the mediastinum and abdomen. She was treated with 2 courses of chemotherapy with docetaxel/ cisplatin/5-FU(DCF therapy). CT and FDG PET-CT showed a significant reduction in both the primary tumor and the metastatic lymph nodes following treatment. We performed subtotal esophagectomy and gastric tube reconstruction with lymphadenectomy. The histopathological findings showed no residual viable tumor cells or foreign body-type giant cells with necrosis. The pathological effect of chemotherapy was defined as Grade 3(pCR). Our case suggested that DCF chemotherapy is potentially a very effective treatment for advanced esophageal cancer with widespread lymph node metastases.

[Surgical Resection for Advanced Gastric Cancer with Portal Vein Tumor Embolus - Two Cases].

Gastric cancer with portal tumor embolus is rare and there is no definite strategy for its surgical resection. We report 2 cases ofgastric cancer with portal vein tumor embolus treated using gastrectomy and thrombectomy. Case 1: The patient was a 56- year-old man. We performed total gastrectomy, distal pancreatectomy, splenectomy, and thrombectomy. The patient was treated with 4 courses ofS -1 plus CDDP chemotherapy followed by S-1 administration. Eight months after surgery, CT revealed metastasis in the left adrenal gland and he died 2 years after surgery. Case 2: The patient was a 57-year-old man. We performed total gastrectomy, distal pancreatectomy, splenectomy, partial resection of the transverse colon, and thrombectomy. The patient was treated using adjuvant S-1 chemotherapy followed by UFT administration for 3 years. The patient has been alive with no tumor recurrence for the past 10 years. If there is no other therapeutic option for portal vein embolus, gastrectomy with thrombectomy could increase the possibility oflong -term survival.