Lymph node metastasis in T1 colorectal cancer: Risk factors and prediction model.

Endoscopic resection is typically performed for early T1 stage colorectal cancer (T1 CRC). Additional surgery is subsequently recommended based on pathological findings; however, the current criteria may result in overtreatment. The present study aimed to re-examine the reported risk factors for lymph node (LN) metastasis in T1 CRC and develop a prediction model using a large multi-institutional dataset. In this retrospective study, the medical records of 1,185 patients with T1 CRC who underwent surgery between January 2008 and December 2020 were investigated. Slides pathologically re-assessable for additional risk factors were re-examined. A total of 251 patients with inadequate data were excluded, and 934 patients were randomly assigned at a ratio of 3:1 to the training and validation datasets. In the univariate analysis, left-sided CRC (P=0.003), deep submucosal invasion depth (P=0.005), poor histological grade (P=0.020), lymphatic invasion (P<0.001), venous invasion (P<0.001) and tumor budding grade 2/3 (P<0.001) were significant risk factors for LN metastasis. A nomogram predicting LN metastasis was developed using these variables, with an area under the received operating characteristic curve (AUC) of 0.786. The nomogram was validated using a validation set with an AUC of 0.721, indicating moderate accuracy. No LN metastases were observed in patients with <90 points using the nomogram; therefore, patients with a low nomogram score may avoid undergoing surgical resection. Prediction of LN metastasis using this developed nomogram may help identify patients who are at high-risk who require surgery.

Ischemia prediction score (IsPS) in patients with strangulated small bowel obstruction: a retrospective cohort study.

BACKGROUNDS: Intestinal ischemia of strangulated small bowel obstruction (SSBO) requires prompt identification and early intervention. This study aimed to evaluate the risk factors and develop a prediction model of intestinal ischemia requiring bowel resection in SSBO. METHODS: This was a single-center, retrospective cohort study of consecutive patients underwent emergency surgery for SSBO from April 2007 to December 2021. Univariate analysis was performed to identify the risk factors for bowel resection in these patients. Two clinical scores (with contrasted computed tomography [CT] and without contrasted CT) were developed to predict intestinal ischemia. The scores were validated in an independent cohort. RESULTS: A total of 127 patients were included, 100 in the development cohort (DC) and 27 in the validation cohort (VC). Univariate analysis showed that high white blood cell count (WBC), low base excess (BE), ascites and reduced bowel enhancement were significantly associated with bowel resection. The ischemia prediction score (IsPS) comprised 1 point each for WBC ≥ 10,000/L, BE ≤ -1.0 mmol/L, ascites, and 2 points for reduced bowel enhancement. The simple IsPS (s-IsPS, without contrasted CT) of 2 or more had a sensitivity of 69.4%, specificity of 65.4%. The modified IsPS (m-IsPS, with contrasted CT) of 3 or more had a sensitivity of 86.7%, specificity of 76.0%. AUC of s-IsPS was 0.716 in DC and 0.812 in VC, and AUC of m-IsPS was 0.838 and 0.814. CONCLUSION: IsPS predicted possibility of ischemic intestinal resection with high accuracy and can help in the early identification of intestinal ischemia in SSBO.

[A Case of Long-Term Survival with Tumor Resection and DOX plus DTIC Therapy for Desmoid Tumor after FAP Surgery].

The patient is a 22-year-old, female. She had a family history of familial adenomatous polyposis(FAP)and a prophylactic total colorectal resection was performed for FAP at age of 18. She presented with fever and abdominal distention and palpated a mass with tenderness in the right lower abdomen. Contrast-enhanced CT scan of the abdomen showed a heterogeneous contrast effect around the tumor margins. With the diagnosis of intra-abdominal desmoid tumor, a partial duodenal resection, small bowel mass resection, and right fallopian tube resection were performed along with the tumor, and an artificial anus was created with the jejunum. Contrast-enhanced CT scan of the abdomen 16 months after resection of desmoid tumor showed a 6.5 cm long desmoid tumor recurrence in the mesentery. She received 5 courses of doxorubicin (DOX)plus dacarbazine(DTIC)therapy followed by continued NSAIDs. Seven years after the operation, she has been able to maintain the shrinkage of the recurrent tumor and is still on medication. Long-term surveillance is necessary because of the possibility of the appearance of other associated lesions in the future.

[A Case of Surgery for Skin Metastasis of Papillary Thyroid Carcinoma in a Very Elderly Patient to Improve the Quality of Life].

The patient was a 100-year-old woman who underwent right lobe thyroidectomy for papillary thyroid cancer in another hospital around 1990. She developed local recurrence in 2010 and underwent anterior tracheal local recurrence resection in May 2017. Subsequently, metastases were confirmed in the lateral cervical lymph nodes, but the patient only received TSH suppression because of her advanced age. Multiple pulmonary metastases developed in November 2020 and supraclavicular lymph node metastases in July 2021, but the patient was under the care of a visiting physician on best supportive care. The patient was referred to our hospital in January 2022 due to the appearance of a cutaneous mass in the sternal incision area, which gradually increased in size. A well-mobile, well-defined, spherical mass was found in the sternotomy area. The maximum diameter was 19 mm. The cytological findings were consistent with cutaneous metastasis of papillary thyroid carcinoma. As the patient was elderly and had multiple pulmonary metastases, she was temporarily observed. However, by June 2022, the mass had increased from 19 mm to 33 mm with cutaneous discoloration. There was no tendency for multiple pulmonary metastases to grow during this period. The decision was made to operate in order to prevent a decline in quality of life due to self-destruction of the cutaneous metastasis. The tumor was removed under general anesthesia, including the cutaneous discoloration, and reconstructed with a rhomboid skin flap. Post-operatively, there was no local recurrence or significant increase in pulmonary metastases. It is suggested that resection of cutaneous metastasis of malignant tumors may be effective in preserving quality of life even in a 100-year-old elderly patient like the present case and should be considered as an indication.

[A Case of Right Hemicolectomy for Inflammatory Myofibroblastic Tumor Arising in the Right Transverse Colon].

The patient was a 21-year-old male. He presented with right lower abdominal pain and showed tenderness in the same area. An abdominal contrast-enhanced CT examination revealed a 45 mm tumor that continuously stained in the right transverse colon. The patient presented with tenderness and rebound tenderness. Due to a suspected submucosal tumor, laparotomy was performed and an elastic hard tumor of 5 cm in size was found on the serous membrane side of the right transverse colon. As malignancy could not be ruled out, a right hemicolectomy with lymph node dissection was performed. The pathological diagnosis was an inflammatory myofibroblastic tumor(IMT), characterized by the proliferation of spindle- shaped spindle-shaped fibroblast-like cells with inflammatory cell infiltration. As of 9 years post-surgery, there has been no recurrence. However, long-term surveillance is necessary.

[Long-Term Survival of a Patient with Advanced Antral Gastric Cancer Successfully Treated with Multidisciplinary Therapy].

We report the case of long-term survival of a patient with advanced antral gastric cancer with multiple paraaortic lymph nodes metastasis who was successfully treated with multidisciplinary therapy. A 70-year-old female was admitted to our hospital complaining of vomiting. Upper gastrointestinal endoscopy revealed a Type 3 tumor in the gastric antrum. Computed tomography(CT)showed a marked decrease in the size of the primary gastric tumor and lymph nodes after 9 courses of mFOLFOX6 therapy. Subsequently, 7 courses of paclitaxel plus ramucirumab(PTX plus Rmab)therapy and 10 courses of nivolumab therapy were administered. After nivolumab therapy, marked shrinkage of the lymph nodes was observed on CT. Distal gastrectomy with D2(+ #16a2+b1)lymph node dissection was performed. The pathological finding was ypT0N1M0 with a Grade 3 effect of the chemotherapy. After 6 months of adjuvant chemotherapy with S-1, CT revealed supraclavicular lymph node metastases. After 4 courses of nivolumab therapy, CT showed a marked increase in the size of the lymph node. Consequently, the regimen was changed to irinotecan. After 16 courses of irinotecan therapy, CT showed a marked shrinkage in the size of the lymph node. The patient is currently alive with no signs of recurrence for 5 years, ie, since the initiation of the multidisciplinary therapy.

[An Experience of Multidisciplinary Treatment for Advanced Esophageal Cancer with Tumor Perforation during Preoperative Chemotherapy].

Perforation of esophageal cancer is one of the fatal oncologic emergencies, and a prompt and accurate treatment strategy is required. Here, we report a case of advanced esophageal cancer that had perforated during preoperative chemotherapy and was successfully resected with multidisciplinary treatment. The prognosis of perforated esophageal cancer can be expected to improve by multidisciplinary treatment appropriately combining initial treatment for infection control and subsequent cancer treatment.

Impact of the COVID-19 pandemic on colorectal cancer surgery in Japan: Clinical Study Group of Osaka University-A multicenter retrospective study.

Aim: Due to the overwhelming spread of SARS-CoV-2 and its disruption of the healthcare system, delays and reduced numbers were reported for colorectal cancer screening, colonoscopies, and surgery during the COVID-19 pandemic. This multicenter retrospective study investigated the still poorly understood impact of the COVID-19 pandemic on colorectal cancer treatment in Japan. Methods: This study was organized by the Clinical Study Group of Osaka University, which comprised 32 major institutions in Osaka. We retrospectively analyzed the number of surgeries and colonoscopies performed and the characteristics of patients who underwent surgery for colorectal cancer between March 2019 and February 2021. We compared data collected before and during the COVID-19 pandemic. We also assessed the methods used for detecting colorectal cancer, including fecal occult blood test, abdominal symptoms, and anemia. Results: The COVID-19 pandemic caused reductions in the annual numbers of surgeries (3569 vs 3198) and colonoscopies (67 622 vs 58 183) performed in the 2020 fiscal year, compared to the 2019 fiscal year. During the COVID-19 pandemic, a significantly lower proportion of patients were treated for clinical stages ≤I (24.2% vs 26.9%; P = .011), compared to the proportion treated before the pandemic. Fecal occult blood tests for detecting colorectal cancer were used significantly less frequently during the COVID-19 pandemic (26.2% vs 29.6%; P = .002). These trends were more significant in larger institutions. Conclusion: The COVID-19 pandemic reduced the number of colonoscopies and surgeries performed for colorectal cancer and hindered the detection of asymptomatic early-stage cancers, and its impact varied by hospital size.

Robotic complete mesocolic excision of right-sided colon cancer with bulky lymph node metastases using the da Vinci® Si™ system: A case report.

Reports on robotic surgery in the treatment of right-sided colorectal cancer most commonly use the da Vinci® Xi™ system; however, with the increasing popularity of robotic surgery for the treatment of colon cancer, it is likely to be performed using the da Vinci Si™ and X™ systems. The present study reported the case of a 63-year-old woman who underwent complete mesocolic excision (CME) with the da Vinci Si system involving a rotation technique for ascending colon cancer with bulky lymph node metastasis to the anterior pancreas. Robot-assisted right hemicolectomy was planned for this patient with T4aN2bM0, stage IIIc cancer. A lap protector and EZ access (Hakko Co. Ltd.) were fixed in the umbilical incision, and the da Vinci camera port was placed just off-center at the EZ access to allow the camera port to be repositioned by rotating it. The medial approach was used. The bulky metastatic lymph nodes at the head of the pancreas were dissected after ligating the right colic artery and vein. During CME, rotation of the EZ access was used to avoid interference between the robotic arms. The right colon was released from the retroperitoneum and resected. A functional end-to-end anastomosis was created, and right colectomy was successfully completed. The total operation time was 271 min and the console time with the da Vinci Si system was 140 min. The patient was discharged on postoperative day 8 without complications. In conclusion, robotic right colectomy was successfully performed and rotation of the EZ access facilitated robotic surgery using the da Vinci Si system.

Risk Factors for Predicting Lymph Node Metastasis in Submucosal Colorectal Cancer.

Objectives: The cornerstone of treating colorectal cancer (CRC) is generally a surgical resection with lymph node (LN) dissection. The tools for predicting lymph node metastasis (LNM) in submucosal (SM) CRC are useful to avoid unnecessary surgical resection. Methods: Retrospectively, we analyzed 526 consecutive patients with SM CRC who underwent surgical resection at the Osaka International Cancer Institute, Osaka University Hospital, and Minoh City Hospital, Japan, between 1984 and 2012. The Osaka International Cancer Institute group and the Osaka University Hospital group were randomly divided into a training set and a test set of 2:1. The prediction model was validated in Minoh City Hospital. Results: We partitioned patients using three risk factors involved in the presence or absence of LNM in SM CRC: lymphatic invasion (Ly), budding grade (BD) and the depth of submucosal invasion (DSI) (cut-off value 2789 µm) that were significantly different in the multivariate analysis. As a result, a predictive model of "LNM <5%" when "Ly negative and DSI <2789 µm" was evaluated. We similarly partitioned by DSI 3000 µm as easy-to-evaluate values in clinical use. We developed the additional model for predicting LNM is 1.05%, that is, LNM <5%, when there are "Ly negative and DSI <3000 µm." Conclusions: As a limitation, only patients who underwent surgical resection were included in this study. This predictive model could help clinicians and CRC patients decide on the additional surgery required after endoscopic resection.

[A Case of Anal Canal Adenocarcinoma with Perianal Pagetoid Spread without a Macroscopic Finding].

We report a case of anal canal cancer with Pagetoid spread without a macroscopic skin lesion. A 54-year-old man was admitted to a hospital with complaints of bloody stools. Endoscopic examination revealed a polyp in the anal canal, and endoscopic mucosal resection was performed. Pathological examination revealed an adenocarcinoma accompanied by Pagetoid spread and the positive surgical margin. We additionally performed trans-anal resection twice, but the resected horizontal margin was positive. Mapping biopsy of rectal mucosa and perianal skin revealed adenocarcinoma in only rectal mucosa. Abdominoperineal resection was performed. Histopathological examination showed invasive adenocarcinoma with pagetoid spread and that the surgical margin was negative. Pagetoid spread of anal canal adenocarcinoma usually showed macroscopic abnormal findings, but in this case, there was no skin lesion. It suggests that preoperative mapping biopsy is helpful for determining the excision range. It is necessary to keep in mind that anal canal adenocarcinoma with no skin lesion may cause Pagetoid spread.

[A Case of Malignant Rectal B Cell Lymphoma That Was Difficult to Differentiate from Rectal Neuroendocrine Tumor].

A 74-year-old woman with a chief complaint of hematochezia was admitted to our hospital. Colonoscopy revealed a 2 cm submucosal tumor with an erosion in the Rb of the rectum. Biopsy showed various inflammatory cell clusters, but no malignant findings. Thoracoabdominal CT and abdominal MRI showed no abnormal findings other than that of rectal wall thickening. Somatostatin receptor scintigraphy performed on suspected rectal NET showed no abnormal accumulation. A total of 3 biopsies were performed, but a definitive diagnosis was not confirmed, and transanal rectal mucosal resection was performed for diagnostic purposes. Immunohistochemistry showed CD20(+)and bcl-2(+), and the lesion was diagnosed as malignant rectal B cell lymphoma. For 1 year postoperatively, the patient showed no recurrence. For this case, biopsy often failed to confirm a definitive diagnosis on rectal submucosal tumors. If the tumor is >1 cm in diameter in a rectal NET, a rectal resection with lymph node dissection is required, and anal function may be impaired. Local tumor excision for diagnosis and treatment may be worthwhile in rectal submucosal tumors if pre-resection diagnosis with biopsy is difficult.

[A Case of Nivolumab Responding to Multiple Lymph Node Metastases during Multidisciplinary Treatment for Esophageal Cancer].

In nivolumab therapy for unresectable advanced esophageal cancer, there are a few cases that show a complete response, and long-term survival can be expected in such cases. Here, we report a case in which nivolumab had a complete response to multiple lymph node metastases during multidisciplinary treatment for esophageal cancer and survived for a relatively long period despite being elderly. Examination of complete response cases provides us with significant insights in considering the unexplained biomarkers of immune checkpoint inhibitors and treatment discontinuation during complete response.

The efficiency of 18F-FDG-PET/CT in the assessment of tumor response to preoperative chemoradiation therapy for locally recurrent rectal cancer.

BACKGROUND: Locally recurrent rectal cancer (LRRC) remains a major problem after curative resection of primary rectal cancer. A noninvasive, prognostic biomarker with which to accurately evaluate disease status and assess the treatment response is critically needed to optimize treatment plans. This study assesses the effectiveness of PET/CT evaluation of preoperative chemoradiation therapy (CRT) in patients with LRRC. METHODS: Since 2004, we have been performing preoperative CRT to improve local tumor control and survival. Between 2004 and 2013, 40 patients with LRRC underwent preoperative CRT (radiation: 50 Gy/25 fractions; chemotherapy: irinotecan plus UFT [tegafur and uracil]/leucovorin) and radical surgery, and underwent 18F-FDG-PET/CT before and 3 weeks after the completion of CRT. The maximum standardized uptake values (SUVmax) of the pre-CRT scan (Pre-SUV) and the post-CRT scan (Post-SUV) were measured. The predictive value of the 18F-FDG-PET and CT/MRI response assessments was evaluated. RESULTS: The mean Pre-SUV was significantly higher than the Post-SUV (8.2 ± 6.1, vs. 3.8 ± 4.0; P < 0.0001). Following CRT, 17/40 patients (42.5%) were classified as responders according to the Mandard tumor regression grade (TRG1-2). The mean Post-SUV was significantly lower in responders than in nonresponders (2.0 ± 1.7 vs. 5.1 ± 3.9; P = 0.0038). Pathological response was not correlated with the response as evaluated by CT (P > 0.9999) or MRI (P > 0.9999). Multivariate regression analysis identified Post-SUV as an independent predictor of local re-recurrence-free survival (P = 0.0383) and for overall survival (P = 0.0195). CONCLUSIONS: PET/CT is useful in assessing tumor response to preoperative CRT for LRRC and predicting prognosis after surgery.

Comparison of Clinical Outcomes Between Laparoscopic and Open Extensive Resection for Complicated Appendicitis: Retrospective Observational Study.

BACKGROUND: The feasibility and safety of laparoscopic extensive resection (ER) for complicated appendicitis (CA) has not been clarified. We assessed the feasibility of laparoscopic ER versus open ER for CA. METHODS: We retrospectively enrolled consecutive 983 patients who underwent emergency surgery for appendicitis, including 91 patients who underwent ER for CA, between April 2007 and October 2019. RESULTS: Thirty-three patients underwent laparoscopic ER, and 58 patients underwent open ER. There were no significant differences in the reasons for performing ER between laparoscopic ER and open ER. The rates of suspicious for malignant tumor did not differ between laparoscopic and open ER [15.2% (5/33) vs. 17.2% (10/58)]. Blood loss was less in laparoscopic ER than in open ER (P=0.028). Superficial surgical site infection was less frequent in laparoscopic ER than in open ER (P=0.047). In addition, laparoscopic ER tended to be associated with a shorter hospital stay, lower rate of postoperative ileus, and higher rate of intra-abdominal abscess. CONCLUSION: Laparoscopic ER is feasible, and it is associated with less intraoperative blood loss and a lower frequency of postoperative superficial surgical site infection than open ER.

[A Case of Recurrent Hepatocellular Carcinoma Successfully Treated by Radiation Therapy].

We report a case of recurrent hepatocellular carcinoma(HCC)successfully treated by radiation therapy. A 79-year-old woman was diagnosed with HCC and underwent liver resection. Seven months after resection, CT and MRI detected a new HCC, and she had a surgery again. One year after the surgery, CT and MRI detected local recurrence, and she underwent the third operation. Three months after the operation, the third liver recurrence was treated by transcatheter arterial chemoembolization( TACE). Four months later, a new lesion was detected and treated by stereotactic body radiation therapy(SBRT) twice. She remains alive without recurrence 27 months after the last radiation therapy. Very few evidence is reported of radiation therapy for HCC, but this case suggests that radiation therapy provides a benefit for patients with HCC after other treatments.

Surgical technique for mesorectal division during robot-assisted laparoscopic tumor-specific mesorectal excision (TSME) for rectal cancer using da Vinci Si surgical system: the simple switching technique (SST).

In a narrow pelvic cavity, performing sufficient tumor-specific mesorectal excision (TSME) is difficult. Even in robot-assisted laparoscopic surgery (RALS), mesorectal division is difficult in a narrow pelvic cavity. To overcome this difficulty, we invented a novel method of mesorectal division. In this new approach, we switched the fenestrated bipolar forceps and the double-fenestrated forceps with each other so that both instruments were placed on the same (right) side of the patient. After the mesorectal fat and vessels were coagulated using the fenestrated bipolar forceps, coagulated tissues were divided using the monopolar scissors in the same direction. We named this technique the "simple switching technique (SST)". We retrospectively collected data and evaluated the usefulness of SST in 24 consecutive patients who underwent RALS TSME between July 2018 and January 2020. Twelve patients underwent SST, and 12 patients underwent other conventional surgical methods (non-SST). The median operation time for mesorectal division was 809.5 s (range 395-1491 s) in the SST group and 985.5 s (range 493-2353 s) in the non-SST group. The coefficient of variation for non-SST was 0.545, which was > 1.5 times the coefficient of 0.360 for SST. Although no significant differences were found for operation time for mesorectal division, the operation time for mesorectal division by SST tended to be shorter than by non-SST (P = 0.157). No significant differences were found regarding short-term outcomes between the groups. SST is feasible and can be an optional method of mesorectal division in RALS TSME.

A new monitoring tool CLIP test for progression of oxaliplatin-induced peripheral neuropathy: A multicenter prospective study.

INTRODUCTION: Oxaliplatin-induced peripheral neuropathy (OIPN) is a common adverse events that can limit a patient's quality of life during/after chemotherapy. However, no appropriate methods have been established yet for monitoring the risk of progression of OIPN. METHODS: A simple assessment tool using gem clips, the CLIP test, was established and its performance in predicting the risk of progression to ≥grade 2 peripheral sensory neuropathy (CTCAE ver. 4.0) was investigated in patients receiving chemotherapy with oxaliplatin. RESULTS: Among 101 patients included in this study, 71 patients developed CTCAE ≥grade 1 peripheral neuropathy (grade 1, n = 67; grade 2, n = 4) at a median of 63 (range, 14-259) days after the start of treatment. Of the 67 patients with grade 1 peripheral neuropathy, 17 showed progression to ≥grade 2 neuropathy after a median interval of 84 (range, 21-246) days. Of these patients, 27 showed a positive result of the CLIP test at a median of 91 (range, 14-224) days, excluding one patient who already showed a positive result of the test at the baseline. Therefore, the risk ratio for the development of CTCAE ≥grade 2 peripheral neuropathy was 8.3 in the patients who showed a positive result on the CLIP test. Multivariate analysis confirmed that a positive results on the CLIP test was significantly correlated with the risk of future development of CTCAE ≥grade 2 peripheral neuropathy (odds ratio, 9.37; P = 0.002). CONCLUSION: A positive result on the CLIP test predict is predictive of the risk of progression of OIPN during chemotherapy with oxaliplatin.

Efficacy of Negative Pressure Wound Therapy Followed by Delayed Primary Closure for Abdominal Wounds in Patients with Lower Gastrointestinal Perforations: Multicenter Prospective Study.

OBJECTIVES: The efficacy of negative pressure wound therapy (NPWT) and its application to severely contaminated wounds sustained during surgery remain to be established. Here, we evaluated the efficacy of utilizing NPWT until delayed primary closure (DPC) by assessing the infection rates in patients with lower gastrointestinal perforations. METHODS: This prospective multicenter cohort study included 56 patients that underwent abdominal surgery for lower gastrointestinal perforations in eight institutions, from February 2016 to May 2017. All patients received NPWT after surgery before attempting DPC. The extent of peritonitis was categorized according to Hinchey's classification. Patients in stages II-IV were included. RESULTS: Five patients had surgical site infections (SSIs) during NPWT and did not receive a DPC (9%). Of the 51 patients that received DPCs, 44 had no infection (91%) and 7 developed SSIs after the DPC (13.7%). For stages II, III, and IV, the SSI rates were 0%, 22.6%, and 35.7%, respectively; the median (range) times to wound healing were 15 (10-36), 19 (11-99), and 19 (10-53) days, respectively. There were no significant differences between the stages. CONCLUSIONS: NPWT followed by DPC resulted in low infection rates in each peritonitis stage. This approach appears promising as an alternative to traditional DPC alone for treating lower gastrointestinal perforations.

[A Case of Advanced Gastric Cancer with Peritoneal Metastasis Achieved Pathological Complete Response by Chemotherapy(SOX Regimen)].

A 68-year-old woman was presented with anorexia. Upper gastrointestinal endoscopy revealed type 4 gastric cancer at corpus of the stomach. Peritoneal metastasis was detected by staging laparoscopy. After a diagnosis of cT4aN1M1, cStage ⅣB advanced gastric cancer, we performed chemotherapy(SOX regimen; S-1 100 mg/body on day 1-14, followed by 7 days of rest, oxaliplatin 130 mg/m2 on day 1). After the 3 courses of chemotherapy, the primary tumor had been reduced. Second staging laparoscopy revealed no peritoneal metastasis. Then, we performed total gastrectomy with D2 lymph node dissection. Histopathological examination revealed no residual cancer cells, indicating a pathological complete response (Grade 3). We report a case of advanced gastric cancer with peritoneal metastasis achieved pathological complete response by chemotherapy.