Single-incision Laparoscopic Colonic Surgery: A Systemic Review, Meta-analysis, and Future Prospect.

Although single-incision laparoscopic surgery (SILS) has gained some attention as a feasible alternative to conventional multiport laparoscopic surgery (MPLS) in colonic surgery, it became less prevalent than expected. Hence, we conducted this systematic review to evaluate the feasibility, safety, and oncological outcomes of single-incision laparoscopic colectomy (SILC) with meta-analysis and discussion of the future prospect of SILS. The search was conducted from September to October 2023 using PubMed and the Cochrane Central Register of Controlled Trials. Articles on colorectal cancer comparing SILC with multiport laparoscopic colectomy (MPLC) from all randomized controlled trials and comparative studies with 50 patients or more per arm were examined. The primary outcomes were the intra- and postoperative complication rates, and the secondary outcomes were the perioperative and oncological outcomes. The trends of the SILS number in Japan and the trends of the number of articles on SILS in PubMed were also reviewed. There were no significant differences in perioperative complication rates, operative factors, and oncological outcomes between SILC and MPLC, although heterogeneity was observed mainly in operative factors and the total length of the skin incision was significantly shorter in SILC. Therefore, SILC is technically and oncologically feasible and safe when performed by experienced laparoscopic surgeons. The case number of SILS was gradually increasing but the rate of SILS was decreasing in Japan. The number of articles on SILS was also decreasing. SILS has gained foothold to some extent but has plateaued. The emerging new robotic platform may reappraise the concept of SILS.

[Questionnaire Survey on Oral Care and Oral Troubles for Patients with Gastric Cancer Received Chemotherapy].

BACKGROUND: The actual situation of oral care and oral troubles for patients with gastric cancer received chemotherapy is not clear. METHODS: Questionnaire survey in the form of oral questions was performed for patients with gastric cancer who received chemotherapy from December 2021 to February 2022. The relevance between the survey results and background factors was examined using the χ2 test. RESULTS: We performed the questionnaire survey for 36 patients. Of the 36 patients, 29 patients received dental check-up before starting chemotherapy. Fourteen of the 29 patients(48%)continued the dental check-up. Of 14 patients who continued the dental check-up, 9 patients were 65 years or older, while 14 of 15 patients who discontinued the dental check-up were 65 years or older. Continuity of dental check-up was low among the elderly patients. The rate of dysgeusia were 78 vs 30% in the patients who adopted and who did not adopt oral care other than toothbrushing(p=0.01). The frequency of oral troubles was dysgeusia(47%), stomatitis(42%), and dry mouth(36%). The severity of the oral troubles was, in order, dysgeusia, dry mouth, and pain. The most common side effect due to chemotherapy causing decreased food intake was dysgeusia. CONCLUSIONS: Dysgeusia was the most frequent and severe oral trouble.

[Regimen Selection by Narrative Approach in Patients with Advanced Gastric Cancer-Paclitaxel or Nab-Paclitaxel?]

BACKGROUND: According to the sixth Gastric Cancer Treatment Guideline, the regimen included nab-paclitaxel(nab-PTX) is a conditional recommendation as second-line treatment for advanced gastric cancer. However, the selection criteria of nab-PTX is not clear. METHOD: Questionnaire survey as narrative approach on the problems of paclitaxel premedication, the symptoms due to paclitaxel containing alcohol, and infusion time was conducted for patients who had been treated with paclitaxel. RESULTS: Thirty-six patients answered the questionnaire. Nonelderly patients(<65 years)or patients without comorbid medications complained of dissatisfaction with the inconvenience due to premedication significantly more than elderly patients(≥65 years)or patients with comorbid medications. Females or nonelderly patients were significantly more troubled by sleepiness due to premedication than males or elderly patients. Eight out of 11 patients who had visited hospital by driving a car for first-line treatment were troubled by prohibition of driving on the day of treatment. Thirty out of 36 patients answered that they would feel benefits from 30-minutes shortening of infusion time. CONCLUSION: Questionnaire survey suggests that we may select the patients for nab-PTX properly by clarifying the inconvenience of daily life associated with premedication, the way of transportation for visiting hospital, and the benefits by shortening of infusion time.

Early endpoints of a randomized phase II trial of preoperative chemotherapy with S-1/CDDP with or without trastuzumab followed by surgery for HER2-positive resectable gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis: Japan Clinical Oncology Group study JCOG1301C (Trigger Study).

BACKGROUND: This randomized phase II study explored the superiority of trastuzumab plus S-1 plus cisplatin (SP) over SP alone as neoadjuvant chemotherapy (NAC) for HER2-positive resectable gastric cancer with extensive lymph node metastasis. METHODS: Eligible patients with HER2-positive gastric or esophagogastric junction cancer and extensive lymph node metastasis were randomized to receive three or four courses of preoperative chemotherapy with SP (arm A) or SP plus trastuzumab (arm B). Following gastrectomy, adjuvant chemotherapy with S-1 was administered for 1 year in both arms. The primary endpoint was overall survival, and the sample size was 130 patients in total. The trial is registered with the Japan Registry of Clinical Trials, jRCTs031180006. RESULTS: This report elucidates the early endpoints, including pathological findings and safety. The study was terminated early due to slow patient accruals. In total, 46 patients were allocated to arm A (n = 22) and arm B (n = 24). NAC was completed in 20 patients (91%) in arm A and 23 patients (96%) in arm B, with similar incidences of grade 3-4 hematological and non-hematological adverse events. Objective response rates were 50% in arm A and 84% in arm B (p = 0·065). %R0 resection rates were 91% and 92%, and pathological response rates (≥ grade 1b in Japanese classification) were 23% and 50% (p = 0·072) in resected patients, respectively. CONCLUSIONS: Trastuzumab can be safely added to platinum-containing doublet chemotherapy as NAC, and it has the potential to contribute to higher antitumor activity against locally advanced, HER2-positive gastric or esophagogastric junction cancer with extensive nodal metastasis.

A patient alive without disease 32 months after conversion surgery following lenvatinib treatment for hepatocellular carcinoma with a tumor thrombus originating in the middle hepatic vein and reaching the right atrium via the suprahepatic vena cava: a case report.

Conversion surgery for initially unresectable hepatocellular carcinoma appears to be increasing in incidence since the advent of new molecular target drugs and immune checkpoint inhibitors; however, reports on long-term outcomes are limited and the prognostic relevance of this treatment strategy remains unclear. Herein, we report the case of a 75-year-old man with hepatocellular carcinoma, 108 mm in diameter, accompanied by a tumor thrombus in the middle hepatic vein that extended to the right atrium via the suprahepatic vena cava. He underwent conversion surgery after preceding lenvatinib treatment and is alive without disease 51 months after the commencement of treatment and 32 months after surgery. Just before conversion surgery, after 19 months of lenvatinib treatment, the main tumor had reduced in size to 72 mm in diameter, the tip of the tumor thrombus had receded back to the suprahepatic vena cava, and the tumor thrombus vascularity was markedly reduced. The operative procedure was an extended left hepatectomy with concomitant middle hepatic vein resection. The tumor thrombus was removed under total vascular exclusion via incision of the root of the middle hepatic vein. Histopathological examination revealed that more than half of the liver tumor and the tumor thrombus were necrotic.

[A Case of 30s Female with Advanced Anal Canal Adenocarcinoma Managed with Adolescent-And-Young-Adult Team].

A 30s female complaining of anal pain and melena was referred to our hospital. The support by adolescent-and-young- adult(AYA)team was initiated after the first encounter. Colonoscopic examination revealed an ulcerated tumor on the anterior wall of anal canal with its anal margin on anal verge and the tumor was diagnosed as an adenocarcinoma. Contrast- enhanced CT and MRI revealed adjacency of tumor and vagina, enlarged lymph nodes and multiple pulmonary nodules. 18F-fluorodeoxyglucose(FDG)-positron emission tomography(PET)additionally revealed tracer accumulation in left sciatica, which led us to the diagnosis of advanced anal cancer. We planned and safely performed concomitant partial vaginal resection in robot-assisted laparoscopic abdominoperineal resection for the palliative purpose after discussion on physical and psychosocial issues including stoma and fertility with the patient, her family and AYA members. The pathological diagnosis was pT4b(vagina)N1aM1b, pStage ⅣB, and the local margin was pathologically negative. The postoperative course was smooth and she was discharged on postoperative day 16. Fifty one days after operation, she started systemic chemotherapy after decision on not to take ovarian samples and continues systemic chemotherapy as of writing. Support by AYA team was effective to facilitate the patient's decision-making and the communication between the patient and the medical team.

[A Case of Diffuse Large B-Cell Lymphoma Which Was Diagnosed during the Best Supportive Care of Recurrent Ascending Colon Cancer].

A 70s male, who had undergone single-incision laparoscopic ileocecal resection for ascending colon cancer with pathological diagnosis of T3N3M0, Stage Ⅲc(without adjuvant chemotherapy), had enhanced-computed tomography(CT)for 3-month follow-up and a hepatic low-density area, an newly emergent nodule behind inferior vena cava and distal ileal tumor were found. Three months later, enhanced CT showed that the distal ileal tumor got exponentially larger and the diagnosis of"malignant lymphoma"was suspected. The patient became sepsis, so we planned and safely performed partial resection of the tumor. The pathological diagnosis was diffuse large B-cell lymphoma. Postoperative course was smooth except for the Clostridium difficile colitis and he was discharged on postoperative day 19. Although the regrowth of the remnant tumor was observed soon after surgery, partial response was confirmed after introduction of systemic chemotherapy. When we cope with malignant lymphoma of small intestine, we need to keep it in mind that surgery is an option for the prevention of perforation and bacterial translocation.

[A Case of Fibromatosis-Like Tumor Which Was Difficult to Differentiate from Local Recurrence of Ascending Colon Cancer].

A 60s female, who had undergone single-incision laparoscopic ileocecal resection for ascending colon cancer with pathological diagnosis of T3N1bM0, Stage Ⅲb, followed by adjuvant therapy with 8 courses CAPOX 2 years ago, had enhanced- computed tomography(CT)for follow-up and a 15-mm nodule near anastomotic site was found. 18F-fluorodeoxyglucose (FDG)-positron emission tomography(PET)CT revealed abnormal accumulation of 18F-FDG only to the lesion and diagnosis of"anastomotic recurrence"was made. We planned and safely performed resection of the anastomotic site and the nodule. The pathological diagnosis was fibromatosis-like tumor without evidence of recurrence, and margin was negative. Postoperative course was smooth and she was discharged on postoperative day 9. When we diagnose local recurrence, we need to keep it in mind that fibromatosis is one of the differential diagnoses, although its incidence rate is low.

Comparison of the effects of open and laparoscopic approach on body composition in gastrectomy for gastric cancer: A propensity score-matched study.

Aim: To compare the effects of open (OG) and laparoscopic gastrectomy (LG) on body composition and muscle strength. Methods: This study performed a propensity score matching analysis using cases from a large-scale, multicenter, phase III randomized controlled trial concerning oral nutritional supplements after gastrectomy and analyzed both the whole and matched cohorts. Measurements of body composition and hand grip strength (HGS) were performed at baseline (preoperatively) and at 1, 2, 3, 6, and 12 months after gastrectomy. Results: Of 835 patients, 275 and 560 underwent OG and LG, respectively. Skeletal muscle mass (SMM) and HGS loss were significantly lesser in the LG group than in the OG group. The propensity score-matched analysis, including 120 pairs of patients, confirmed that the % SMM loss values at 1, 2, 3, 6, and 12 POM were -4.5%, -4.0%, -4.7%, -4.6%, and -5.8% in the OG group and -3.0%, -1.9%, -2.4%, -2.2%, and -2.7% in the LG group, respectively. The % SMM loss was significantly lesser in the LG group than in the OG group (repeated measures ANOVA p < 0.001). The HGS loss was non-significantly smaller in the LG group than in the OG group. Conclusion: Skeletal muscle mass loss was significantly lesser in the LG group than in the OG group in both cohorts, indicating that LG may be more effective than OG for maintaining muscle mass.

Association between the antiadhesion membrane and small bowel obstruction after open gastrectomy: A supplemental analysis of the randomized controlled JCOG1001 trial.

Aim: Postoperative small bowel obstruction (SBO) is one of the major complications that is mainly caused by postoperative adhesion. Recently, the antiadhesion membrane has become popular for postoperative SBO prevention. However, its efficacy is yet to be confirmed in the gastric cancer surgery field. Here, we conducted the supplemental analysis of the randomized controlled trial JCOG1001 to investigate the efficacy of the antiadhesion membrane on SBO prevention in patients with open gastrectomy for gastric cancer. Methods: Of the 1204 patients enrolled in JCOG1001, 1200 patients were included. The development of SBO of Grade ≥ IIIa according to the Clavien-Dindo classification was recorded. Univariable and multivariable analyses were performed using the Fine and Gray model to determine the risk factors for SBO. Results: Fifty-one patients developed SBO (median follow-up duration: 5.6 years). Total gastrectomy, combined resection, and blood loss significantly increased the risk for SBO development in the univariable analysis. Large amount of blood loss was independently associated with SBO development in the multivariable analysis (hazard ratio [HR], 3.089; 95% confidence interval [CI], 1.562-6.109, p = 0.0012). Antiadhesion membrane did not reduce the risk for SBO (HR, 1.299; 95% CI 0.683-2.470; p = 0.4246). In the patients belonging to subgroup analyses who received distal and total gastrectomy, the antiadhesion membrane was not associated with the incidence of SBO. Conclusions: Antiadhesion membrane did not decrease SBO occurrence rate after open gastrectomy. Therefore, the use of antiadhesion membrane would not be effective for preventing SBO in gastric cancer surgery.

Phase II study of S-1 plus docetaxel as first-line treatment for older patients with advanced gastric cancer (OGSG 0902).

BACKGROUND: Although there is insufficient evidence for the treatment of older patients with advanced gastric cancer, fluorouracil combined with platinum chemotherapy has been recognized as a standard first-line treatment for such populations in Japan despite the lack of efficacy and toxicity data. METHODS: Patients aged 75 years or older with advanced gastric cancer were enrolled. S-1 plus docetaxel (docetaxel: 40 mg/m2, day 1; S-1: 80 mg/m2, days 1-14; q21 days) was repeated every 3 weeks. The primary endpoint was overall response rate. Secondary endpoints were safety, progression-free survival, time to treatment failure, and overall survival. The sample size was calculated as 30 under the hypothesis of an expected response rate of 40% and a threshold response rate of 20%, at a power of 90% and a two-sided alpha value of 5%. RESULTS: From February 2010 to January 2015, 31 patients were enrolled and assessed for efficacy and toxicity. The response rate was 45.2% (95% CI 27.3%-64.0%; p = 0.001) and it exceeded the expected response rate set at 40%. Median progression-free survival was 5.8 months, the 1-year survival rate was 58.1%, and the median survival time was 16.1 months. The major grade 3/4 adverse events were neutropenia (58%), febrile neutropenia (13%), anemia (10%), anorexia (10%), and fatigue (6%). CONCLUSIONS: These findings indicate that S-1 plus docetaxel as first-line treatment for older patients is feasible and that it has promising efficacy against advanced gastric cancer.

Effects of postoperative oral elemental nutritional supplement on skeletal muscle loss after gastrectomy for gastric cancer.

BACKGROUND: We previously showed that daily nutritional intervention with an oral elemental diet (ED) at 300 kcal/day for 6-8 weeks postoperatively decreased the percentage of body weight loss (%BWL), and that the effect was maintained for 1 year. This post hoc analysis aimed to determine whether this intervention decreased skeletal muscle mass loss 1-year post-gastrectomy. METHODS: Data from consecutive, untreated patients with histopathologically confirmed stage I-III gastric adenocarcinoma who planned to undergo total gastrectomy (TG) or distal gastrectomy (DG) and were enrolled in a previously published randomized trial were used. The primary endpoint was the percentage of skeletal muscle mass index (%SMI) loss from baseline at 1 year postoperatively, based on abdominal computed tomography images obtained preoperatively and at 1 year postoperatively. RESULTS: The overall median %SMI loss was lower in the ED versus control group, but the difference was not significant. The difference in %SMI loss in the ED and control groups was greater in patients with TG (10.1 vs. 13.0; P = 0.12) than in those with DG (5.5 vs. 6.8; P = 0.69). A correlation was observed between %BWL and %SMI loss in both groups (ED group, coefficient 0.591; control group, coefficient 0.644; P < 0.001 for both). Type of gastrectomy (coefficient 7.38; P = 0.001) and disease stage (coefficient - 6.43; P = 0.04) were independent predictors of postoperative skeletal muscle mass loss. CONCLUSION: ED administration for 6-8 weeks following gastrectomy had no inhibitory effect on skeletal muscle loss at 1 year postoperatively. CLINICAL TRIAL REGISTRATION: UMIN000023455.

Phase II Study of Intraperitoneal Administration of Paclitaxel Combined with S-1 and Cisplatin for Gastric Cancer with Peritoneal Metastasis.

BACKGROUND: Intraperitoneal chemotherapy is promising for gastric cancer with peritoneal metastasis. Although a phase III study failed to show a statistically significant superiority of intraperitoneal paclitaxel combined with S-1 and intravenous paclitaxel, the sensitivity analysis suggested clinical efficacy. Thus, attempts to combine intraperitoneal paclitaxel with other systemic therapies with higher efficacy have been warranted. We sought to explore the efficacy of intraperitoneal paclitaxel with S-1 and cisplatin. PATIENTS AND METHODS: Gastric cancer patients with peritoneal metastasis were enrolled in the phase II trial. In addition to the established S-1 and cisplatin regimen every 5 weeks, intraperitoneal paclitaxel was administered on days 1, 8, and 22 at a dose of 20 mg/m2. The primary endpoint was overall survival rate at 1 year after treatment initiation. Secondary endpoints were progression-free survival and toxicity. RESULTS: Fifty-three patients were enrolled and fully evaluated for efficacy and toxicity. The 1-year overall survival rate was 73.6% (95% confidence interval 59.5-83.4%), and the primary endpoint was met. The median survival time was 19.4 months (95% confidence interval, 16.1-24.6 months). The 1-year progression-free survival rate was 49.6% (95% confidence interval, 34.6-62.9%). The incidences of grade 3/4 hematological and non-hematological toxicities were 43% and 47%, respectively. The frequent grade 3/4 toxicities included neutropenia (25%), anemia (30%), diarrhea (13%), and anorexia (17%). Intraperitoneal catheter and implanted port-related complications were observed in four patients. There was one treatment-related death. CONCLUSIONS: Intraperitoneal paclitaxel combined with S-1 and cisplatin is well tolerated and active in gastric cancer patients with peritoneal metastasis.

Association between methicillin-resistant Staphylococcus aureus nasal carriage and infection after pancreatic surgery.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infections after pancreatectomy are relatively rare; however, they can be fatal when associated with pseudoaneurysms. For the past 12 years, we have been investigating nasal MRSA carriage by polymerase chain reaction testing, postoperatively in patients admitted to the intensive care units, to prevent nosocomial infections. Here, we investigated the relationship between MRSA nasal carriage and postoperative MRSA infection at the surgical site, following pancreatectomy. METHODS: This single-center retrospective study analyzed 313 pancreatectomies (220 pancreaticoduodenectomies and 93 distal pancreatectomies), performed at our hospital between January 2011 and June 2022. The incidence of surgical site infection (SSI) and postoperative MRSA infection were compared between the nasal MRSA-positive and nasal MRSA-negative groups. RESULTS: MRSA nasal carriage was identified in 24 cases (7.6%), and the frequency of SSIs in the nasal MRSA-positive and MRSA-negative groups were 50% and 36.7%, respectively, with no significant difference (p = .273). However, the frequency of MRSA infection among the SSI cases was significantly higher in the nasal MRSA-positive group (16.7%) than in the nasal MRSA-negative group (1.7%) (p = .003). CONCLUSION: It should be noted that MRSA carriers have a significantly higher frequency of MRSA-positive SSIs.

Intravascular Large B-Cell Lymphoma in Acute Hypoxic Respiratory Failure.

Intravascular large B-cell lymphoma, an extranodal large B-cell lymphoma, is a rare hematological malignancy with only a few reports of lung involvement. We report a case of intravascular large B-cell lymphoma with acute hypoxic respiratory failure and interstitial lung disease diagnosed via random skin biopsies. A 54-year-old woman presented with fever, cough, and dyspnea. Computed tomography imaging revealed findings concerning interstitial lung disease. The patient's respiratory status worsened despite the treatment with antibiotics and steroids. Generalized edema and thrombocytopenia also developed. Intravascular large B-cell lymphoma was clinically suspected and ultimately diagnosed by skin biopsy, although she had no apparent skin lesions. The patient's condition considerably improved after chemotherapy. Intravascular large B-cell lymphoma should be considered in patients with acute respiratory failure and interstitial lung lesions.

Multicenter phase II study of capecitabine plus oxaliplatin in older patients with advanced gastric cancer: the Tokyo Cooperative Oncology Group (TCOG) GI-1601 study.

BACKGROUND: Capecitabine plus oxaliplatin (CapeOX) is a standard treatment option for advanced gastric cancer (AGC). We conducted a prospective multicenter phase II study to evaluate the efficacy and safety of CapeOX as a first-line therapy for AGC in older patients. METHODS: Chemotherapy-naive patients aged ≥ 70 years with AGC were eligible. Initial treatment comprised capecitabine (2000 mg/m2 on days 1-14) and oxaliplatin (130 mg/m2 on day 1) every 3 weeks. After the initial feasibility assessment, the dose was reduced considering toxicity (capecitabine, 1500 mg/m2 on days 1-14; and oxaliplatin, 100 mg/m2 on day 1 every 3 weeks). The primary endpoint was overall survival (OS). RESULTS: In total, 108 patients were enrolled, of whom 104 were evaluated. Thirty-nine patients received the original-dose treatment, whereas 65 received the reduced-dose treatment. The median OS, progression-free survival (PFS), and time to treatment failure (TTF) were 12.9 (95% CI 11.6-14.8), 5.7 (95% CI 5.0-7.0), and 4.3 (95% CI 3.9-5.7) months, respectively, for all patients; 13.4 (95% CI 9.5-16.0), 5.8 (95% CI 4.1-7.8), and 5.3 (95% CI 3.5-7.2) months in the original-dose group; and 12.8 (95% CI 11.3-15.3), 5.7 (95% CI 4.4-7.0), and 4.1 (95% CI 3.7-5.7) months in the reduced-dose group. The most common grade 3/4 toxicities were neutropenia (17.9%), anemia (12.8%), and thrombocytopenia (12.8%) in the original-dose group and neutropenia (13.8%) and anorexia (12.3%) in the reduced-dose group. CONCLUSIONS: These findings demonstrate CapeOX's efficacy and safety in older AGC patients.

Identifying Risk Factors of Complications following Total Gastrectomy for Gastric Cancer: Comparison between Splenectomy and Spleen-Preserving Surgery - A Supplementary Analysis of JCOG0110.

INTRODUCTION: Splenectomy for proximal gastric cancer was found to offer no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). Although many studies have explored risk factors for morbidities following total gastrectomy, none have assessed the risk factors for postoperative complications in spleen-preserving total gastrectomy. METHODS: Using data from 505 patients enrolled in a previous randomized trial, risk factors for postoperative complications were identified by multivariable logistic regression analysis. Then, the risk factors were assessed separately between splenectomy and spleen-preserving total gastrectomy. RESULTS: Postoperative complications were identified in 119 patients (23.6%) and were more common following splenectomy than following spleen-preserving surgery (30.7% and 16.1%, respectively, p < 0.01). Multivariable analysis revealed that age ≥65 years (p = 0.032), body mass index ≥25 (p = 0.003), and blood loss ≥350 (p = 0.019) were independent risk factors for postoperative complications in the entire cohort. Among them, only body mass index was a significant independent risk factor for complications in both spleen preservation (p = 0.047) and splenectomy groups (p = 0.017). CONCLUSION: Risk factors for postoperative complications were essentially the same between splenectomy and spleen preservation. Being overweight increased the risk of postoperative complications.

The effect of specimen processing time on HER2 expression in gastric cancer and esophagogastric junction cancer: a single-center retrospective observational study.

BACKGROUND: Recent developments in the field of companion diagnosis and molecular-targeting therapeutic agents have helped in developing treatments targeting human epidermal growth factor receptor 2 (HER2) in gastric cancer (GC) and esophagogastric junction cancer (EGJC), and the importance of accurate diagnosis of HER2 expression is increasing. However, the HER2-positivity rate significantly differs among reports in GC and EGJC, and factors that affect HER2-positivity require elucidation. METHODS: The present study retrospectively examined factors related to HER2-positivity in a single institution, including age, sex, body mass index, the American Society of Anesthesiologists physical status, tumor information, and surgery information, including time to specimen processing. RESULTS: Our study included 165 patients tested for HER2 using GC and EGJC surgery specimens among the 1,320 patients who underwent gastrectomy from January 2007 to June 2022. In total, 35 (21.2%) and 130 (78.8%) patients were HER2-positive and -negative, respectively. Multivariate analysis revealed that intestinal type (odds ratio [OR]: 3.41, 95% confidence interval [CI]: 1.44-8.09, p = 0.005), pM1 (OR: 3.99, 95% CI: 1.51-10.55, p = 0.005), and time to specimen processing of < 120 min (OR: 2.65, 95% CI: 1.01-6.98, p = 0.049) were independent factors that affected HER2-positivity. CONCLUSIONS: The outcomes of the present study indicated that intestinal type, pM, and time to specimen processing are important factors affecting HER2-positive rates in GC and EGJC. Therefore, the risk of false-negative HER2 results may be reduced by decreasing the time required to process the resected specimen. Additionally, accurate diagnosis of HER2 expression may increase the opportunity to administer molecular-targeted drugs that can expect therapeutic effects to patients appropriately. TRAIL REGISTRATION: Retrospectively registered.