Early detection of occupational cholangiocarcinoma in a high-risk patient under intensive surveillance: a case study.

BACKGROUND: Occupational cholangiocarcinoma is associated with exposure to organic solvents, such as dichloromethane (DCM) and 1,2-dichloropropane (DCP). This report describes a case of occupational cholangiocarcinoma detected through regularly imaging following the discovery of elevated serum γ-glutamyl trans peptidase (γ-GTP) levels revealed during regular checkup. CASE PRESENTATION: A 43-year-old man who had been working in a printing company with 15 years of exposure to organic solvents presented to our hospital owing to abnormalities found during a routine checkup. Ultrasound (US) imaging revealed thickening of the gallbladder wall accompanied by gallstones, although in the blood tests, γ-GTP levels were within normal range. Given the high risk of cholangiocarcinoma development, the patient underwent regular monitoring with abdominal US and blood tests at a local doctor's office. At the age of 48, his serum γ-GTP level mildly elevated for the first time, prompting the initiation of semi-annual magnetic resonance cholangiopancreatography (MRCP). By the age of 50 years, dilation in B8 was detected, and one and a half years later, a tumor on the central side of the B8 dilation appeared. The patient was diagnosed with intrahepatic cholangiocarcinoma, which was treated with anterior sectionectomy. Pathological examination revealed an adenocarcinoma with a papillary glandular ductal structure at the root of the B8. In addition, biliary intraepithelial neoplasia (BilIN) and dysplasia have been identified around the tumor and periphery bile ducts and in noncancerous bile ducts. Postoperatively, the patient received 6 months of adjuvant chemotherapy with S-1monotherapy. Eight months after surgery, the patient remained under observation with no signs of recurrence. CONCLUSIONS: We report a case of occupational cholangiocarcinoma detected during a prolonged period of regular follow-up after exposure to DCM and DCP. Given the delayed carcinogenesis process, occupational cholangiocarcinomas manifest long after exposure to organic solvents, therefore, ongoing screening is extremely important. Vigilance is essential to avoid underdiagnosis, particularly for individuals who are at an increased risk of developing this form of cancer. Continuous monitoring is key to the early detection and effective management of occupational cholangiocarcinoma.

Portal vein wedge resection and patch venoplasty with autologous vein grafts for hepatobiliary-pancreatic cancer.

BACKGROUND: Advanced hepatobiliary-pancreatic cancer often invades critical blood vessels, including the portal vein (PV) and hepatic artery. Resection with tumor-free resection margins is crucial to achieving a favorable prognosis in these patients. Herein, we present our cases and surgical techniques for PV wedge resection with patch venoplasty using autologous vein grafts during surgery for pancreatic ductal adenocarcinoma (PDAC) and perihilar cholangiocarcinoma (PhCC). CASE PRESENTATION: Case 1: 73-year-old female patient with PDAC; underwent subtotal stomach-preserving pancreatoduodenectomy, with superior mesenteric vein wedge resection and venoplasty with the right gonadal vein. Case 2: 67-year-old male patient with PDAC; underwent distal pancreatectomy and celiac axis resection, with PV wedge resection and venoplasty with the middle colic vein. Case 3: 51-year-old female patient with type IV PhCC; underwent left hepatectomy with caudate lobectomy and bile duct resection, with hilar PV wedge resection and venoplasty with the inferior mesenteric vein (IMV). Case 4: 69-year-old male patient with type IIIA PhCC; underwent right hepatopancreatoduodenectomy, with hilar PV resection and patch venoplasty with the IMV. All patients survived for over 12 months after the surgery, without local recurrence. CONCLUSIONS: PV wedge resection and patch venoplasty is a useful technique for obtaining tumor-free margins in surgeries for hepatobiliary-pancreatic cancer.

Crohn's disease-related anal fistula cancer diagnosed by examination under anesthesia: a case report.

BACKGROUND: As the number of patients with inflammatory bowel disease (IBD) increases, the incidence of IBD-related colorectal cancer (CRC) is also on the rise. Crohn's disease (CD)-related CRC has been reported to have a poorer prognosis than sporadic CRC, and the early detection of CD-related CRC is difficult. Japanese patients with CD are reported to have a higher frequency of anorectal cancer than the Western population; however, methods for early diagnosis have not yet been established because of perianal pain during the examination. CASE PRESENTATION: We report a case of CD-related anal fistula cancer that was detected early by surveillance examination under anesthesia (EUA). The patient was a 37-year-old man, diagnosed with CD at the age of 15 years and started medical treatment. However, due to poor disease control, the intestinal tract remained highly inflamed and the patient continued to have over 10 bowel movements per day. He was referred to our hospital for surgical treatment after a colonoscopy (CS), which revealed multiple active ulcers and stenoses. Since three perianal seton drainage tubes had been placed around his anus since the age of 33 years, we decided to perform an EUA to rule out cancer coexistence in the anorectal region. After a random biopsy of the rectum by CS under general anesthesia, we resected and curetted multiple perianal fistulas as much as possible and reinserted the seton drainage tubes. Pathological examination of the fistula tract revealed adenocarcinoma in one tract, indicating the coexistence of anal fistula cancer. Based on the diagnosis of multiple intestinal stenoses and anal fistula cancer due to CD, we performed hand-assisted laparoscopic total colectomy, rectal amputation, extensive perineal resection, and reconstruction using a left rectus abdominis flap. CONCLUSION: In a long-term CD patient with anorectal lesions, we performed an EUA to diagnose the coexistence of anal fistula cancer at an early stage, and surgical resection was achieved. EUA is effective for the early detection and treatment of CD-related CRC and may contribute to an improved prognosis.

[A Case Report-A Successful Case of Distal Pancreatectomy with En Bloc Celiac Axis Resection for Locally Advanced Pancreatic Cancer with an Aberrant Right Hepatic Artery].

In cases of pancreatic cancer with anatomical variations of the hepatic artery, it is important to evaluate the hemodynamics of each case for surgical indication. We report the case of a 68-year-old man with locally advanced pancreatic cancer and an aberrant right hepatic artery who underwent distal pancreatectomy with celiac axis resection(DP-CAR). He was admitted to our institute due to abdominal discomfort. A CT scan showed pancreatic cancer invading the common hepatic artery. He underwent chemoradiotherapy with a diagnosis of locally advanced pancreatic cancer. After the tumor downstaging, we performed DP-CAR, which included a gastroduodenal artery and a proper hepatic artery resection. Even though delayed gastric emptying was observed after the operation, he was discharged on postoperative day 36.

[FOLFIRI plus RAM Therapy in Later Line of Unresectable Colorectal Cancer].

FOLFIRI plus ramucirumab(RAM)therapy has been reported to be effective and safe in the RAISE trial as second-line treatment for unresectable colorectal cancer. It is hypothesized that RAM may be effective in patients with PD treated with FOLFIRI plus bevacizumab(Bev)due to different mechanism of action from that of Bev, which is also an angiogenesis inhibitor. From January 2017 to December 2021, we conducted a retrospective study of 6 patients who had PD with 5-FU, oxaliplatin, irinotecan, or Bev as first or second-line treatment at our institution and who received FOLFIRI plus RAM in later line treatment. The 6 cases consisted of 3 patients in the third-line treatment, 1 patient in the fourth-line treatment, and 2 patients in the sixth-line treatment. The anti-tumor effect was PD in all cases in the third-line and fourth-line treatment, but the 2 patients of sixth-line treatment were controlled diseases.

Clinical outcomes of single incision laparoscopic surgery for colorectal cancer: A propensity score-matched analysis between well-experienced and novice surgeons.

Background: Single incision laparoscopic surgery (SILS) is a recent advancement in minimally invasive techniques for colorectal cancer (CRC). However, SILS is a technically challenging procedure for novice surgeons. The aim of this study was to evaluate clinical outcomes of SILS for CRC performed by novice surgeons compared with those performed by well-experienced surgeons. Methods: We retrospectively analyzed 1004 consecutive patients with stage I-IV CRC who underwent SILS between May 2009 and December 2018, using propensity score-matched analysis. Results: After propensity score-matching, we enrolled 344 patients (n = 172 in each group). Before matching, significant group-dependent differences were observed in terms of age (P = 0.034) and tumor location (P < 0.001). After matching, preoperative clinical factors were similar between groups, but operative time was longer in the Novice group (213 vs 171 min, P < 0.001). Other operative factors and morbidity rates did not differ significantly between groups. The number of harvested lymph nodes was smaller in the Novice group (23 vs 25, P = 0.040), and the number of patients with lymph node metastases was smaller in the Novice group (57 vs 86, P = 0.002). The 3-year disease-free survival rate was 85.8% in the Novice group and 89.9% in the Experienced group (P = 0.512). Three-year overall survival rate was 92.2% in the Novice group and 90.0% in the Experienced group (P = 0.899). Conclusion: SILS for CRC was safely performed by novice surgeons under the guidance of well-experienced surgeons, and could provide satisfactory oncological outcomes.

Clinicopathological features of appendiceal goblet cell adenocarcinoma in Japan: a multicenter retrospective study.

PURPOSE: In the 5th edition of the World Health Organization classification, appendiceal goblet cell adenocarcinoma (GCA) is categorized separately from neuroendocrine tumors and other appendiceal adenocarcinomas. We clarified the clinicopathological characteristics of Japanese appendiceal GCA. METHODS: We designed a retrospective multicenter cohort study and retrieved the data of patients with appendiceal neoplasms and histologically diagnosed appendiceal goblet cell carcinoid (GCC) treated from January 2000 to December 2017 in Japan. The available GCC slides were reviewed and diagnosed with a new grading system of GCA. RESULTS: A total of 922 patients from 43 institutions were enrolled; of these, 32 cases were patients with GCC (3.5%), and 20 cases were ultimately analyzed. The 5-year survival rate was 61.4% (95% confidence interval: 27.4-83.2), and the median survival time was 93.1 months. For peritoneal metastasis, regional lymph node metastasis was a significant factor (p = 0.04), and Grade 3 was a potential factor (p = 0.07). No peritoneal metastasis was observed in either T1/2 patients (n = 2) or Grade 1 patients (n = 4). We were unable to detect any significant factors associated with regional lymph node metastasis. CONCLUSION: For peritoneal metastasis, regional lymph node metastasis was a significant factor, and Grade 3 was a potential factor.

[A Case of Locally Advanced Giant Sigmoid Colon Cancer Successfully Treated with Neoadjuvant Chemotherapy].

A 51-year-old woman presented to our hospital complaining of a lower abdominal mass and dysuria. She was diagnosed with advanced sigmoid colon cancer. The tumor was large, involving the bladder, and occupying the pelvic cavity. She received neoadjuvant chemotherapy with 4 courses of mFOLFOX6, in addition to panitumumab. The treatment resulted in a marked reduction of the tumor. A laparoscopic sigmoid colon resection, total cystectomy, neobladder reconstruction, complete uterine and bilateral adnexa resection and partial ileal resection were performed. The histopathological diagnosis was ypT4b(bladder), ypN0, ypStage Ⅱc, all with negative surgical margins. Adjuvant chemotherapy was not administered owing to the patient's refusal. She remained recurrence-free for 3 years of postoperative follow up.

Comparison of clinical outcomes of single-incision versus multi-port laparoscopic surgery for descending colon cancer: a propensity score-matched analysis.

BACKGROUND: The clinical impact of single-incision laparoscopic surgery (SILS) for descending colon cancer (DCC) is unclear. The aim of this study was to evaluate the clinical outcomes of SILS for DCC compared with multi-port laparoscopic surgery (MPLS). METHODS: We retrospectively analyzed 137 consecutive patients with stage I-III DCC who underwent SILS or MPLS at two high-volume multidisciplinary tertiary hospitals between April 2008 and December 2018, using propensity score-matched analysis. RESULTS: After propensity score-matching, we enrolled 88 patients (n = 44 in each group). SILS was successful in 97.7% of the matched cohort. Compared with the MPLS group, the SILS group showed significantly less blood loss and a greater number of harvested lymph nodes. Morbidity rates were similar between groups. Recurrence pattern did not differ between groups. No significant differences were found between groups in terms of 3-year disease-free and overall survivals. CONCLUSION: SILS appears safe and feasible and can provide satisfactory oncological outcomes for patients with DCC.

Comparison of clinical outcomes of single-incision versus multi-port laparoscopic surgery for rectosigmoid or upper rectal cancer.

BACKGROUND: Single-incision laparoscopic surgery (SILS) for rectal cancer is technically challenging, and its clinical impact is unclear. The aim of this study was to evaluate clinical outcomes of SILS for rectal cancer compared with multi-port laparoscopic surgery (MPLS). PATIENTS AND METHODS: We retrospectively analyzed 357 consecutive patients with stage I-III rectal cancer located in the rectosigmoid or upper rectum who underwent SILS or MPLS between January 2012 and December 2016, using propensity score-matched analysis. RESULTS: After propensity score-matching, we enrolled 204 patients (n = 102 per group). Before matching, significant group-dependent differences were observed in tumor location (p < 0.001). After matching, preoperative clinical factors were similar between groups. SILS was successful in 73.5% of cases, an additional port was required in 23.5%, and 2.9% were converted to open surgery. Compared to the MPLS group, the SILS group showed shorter operative time (192 vs. 211 min, p = 0.015) and shorter postoperative hospital stay (9 vs. 11 days, p = 0.038). Other operative factors and morbidity rates did not differ significantly between groups. The number of harvested lymph nodes was smaller in the SILS group (24) than in the MPLS group (27, p = 0.008). Postoperative recurrence did not differ between groups, either before or after matching. No significant differences in 3-year disease-free, 3-year local recurrence-free, or 5-year overall survival were found between groups. CONCLUSIONS: SILS is safe, is feasible, and offers satisfactory oncological outcomes in selected patients with rectosigmoid or upper rectal cancer.

Vascular variants in laparoscopic extended right hemicolectomy with central vascular ligation for right colon cancer.

PURPOSE: To evaluate the right colic vascularity, focusing on the confluences of veins. METHODS: The subjects of this retrospective study were 100 patients who underwent laparoscopic extended right hemicolectomy (Lap-ERHC) between April 2015 and September 2020, at our hospitals. Veins draining into the superior mesenteric vein (SMV) included the ileocecal vein (ICV), the right colic vein (RCV), the middle colic vein (MCV), and the gastrocolic trunk of Henle (GCT). Veins draining into vessels other than the SMV were defined as accessory colic veins (aICV, aRCV or aMCV). RESULTS: The GCT, aRCV, and aMCV were found in 86, 89, and 15 patients, respectively. In 66 patients with one aRCV, drainage was split as the anterior superior pancreaticoduodenal vein (ASPDV) in 12, the right gastroepiploic vein (RGEV) in 7, and the GCT in 47. In 23 patients with two aRCVs, drainage was split as the ASPDV in 4, the RGEV in 1, the GCT in 11, and the ASPDV and GCT in 7. In 14 patients with one aMCV, drainage was split as the GCT in 8, the splenic vein in 5, and the first jejunal vein (FJV) in 1. One patient had two aMCVs, draining into the GCT and the FJV. CONCLUSIONS: The findings of our evaluation of vascular anatomy, focusing on confluences of the colic veins, provides useful information for colorectal surgeons.

A Phase II Study of Dose-reductive XELOX Plus Bevacizumab in Elderly or Vulnerable Patients With Metastatic Colorectal Cancer (MCSGO-1202).

BACKGROUND/AIM: This phase II study (MCSGO-1202) aimed to evaluate the initial dose reduction of oxaliplatin in XELOX plus bevacizumab therapy. PATIENTS AND METHODS: This was a phase II, multicenter, open-label, single-arm, prospective, study conducted at 14 Japanese institutions. The study included patients with metastatic colorectal cancer (mCRC) with performance status (PS) of 1 or 2 who had not undergone chemotherapy. Patients received oxaliplatin (100 mg/m2) plus bevacizumab (7.5 mg/kg) on day 1 and capecitabine (2,000 mg/m2/day) on days 1-14 of a 21-day cycle. The primary endpoint was the objective response rate. The secondary endpoints were progression-free and overall survival, 1-year survival rate, disease control rate, dose intensity, and adverse events. RESULTS: Between April 2012 and March 2016, 56 patients were enrolled. The median age was 71 years (range=44-85 years), and the majority (90.6%) had a PS of 1. A complete response was observed in three patients (5.7%), partial response in 24 (45.3%), stable disease in 22 (43.4%), and progressive disease in one (1.9%). The median progression-free survival and overall survival were 11.4 and 26.5 months, respectively. The most common grade 3-4 adverse events were leucopenia (15.1%), neutropenia (9.4%), neuropathy (9.4%). CONCLUSION: The dose-reduction strategy of oxaliplatin was effective for elderly or vulnerable patients with mCRC.

Single-Incision Laparoscopic Cholecystectomy: a Single-Centre Experience of 1469 Cases.

BACKGROUND: Despite having once been extensively used for cosmetics or pain reduction, the use of single-incision laparoscopic cholecystectomy (SILC) has declined in recent years due to technical difficulties and a reported increase in complications. Since the introduction of SILC in 2009, our hospital has been actively involved with this technique. Our experience suggests that SILC is not a difficult procedure and can be safe and useful, with particularly excellent cosmetic outcomes. This study retrospectively details the outcomes of SILC at our hospital. METHOD: Data on 1469 cases of SILC performed on a waitlist basis at Osaka Police Hospital from May 2009 to December 2020 were collected and retrospectively analysed. RESULTS: The median operative time and blood loss were 96 min and 0 mL, respectively. A total of 46 patients (3.1%) required conversion surgery, including 36 needing additional ports and 10 requiring laparotomy. Intraoperative complications included common bile duct injury in 1 patient (0.07%) and right hepatic artery injury in 1 patient (0.07%), with no other organ injury. Postoperative Clavien-Dindo 3 or higher complications were observed in 18 patients (1.2%). Incisional hernias occurred in 15 patients (1.0%). The median postoperative hospital stay was 3 days. CONCLUSION: This study showed that SILC can be performed safely without any increase in complications, as reported previously. Granted that it is performed safely, SILC may be a useful technique due to its superior cosmetic outcomes or pain reduction.

Laparoscopic mesh removal for mesh infection related to pararectal incision of previous appendectomy after laparoscopic total extraperitoneal inguinal hernia repair: A case report.

A 67-year-old man with a history of appendectomy 40 years ago underwent single-incision laparoscopic surgery for total extraperitoneal inguinal hernia repair. Postoperatively, the pararectal incisional scar obtained from the appendectomy was infected; thus, antibiotic therapy and drainage were performed. However, the infection persisted. After 5 postoperative months, the mesh was laparoscopically removed at a sufficient distance from the infected site. No enterocutaneous fistula was observed. After 1 year and 10 months, no recurrence of hernia or infection was observed. Thus, laparoscopic mesh removal is feasible. Infection of a 40-year-old incision rarely results in mesh infection. Therefore, in pararectal incision, the extent of mesh coverage should be considered; if the overlap is large, changing the technique by not covering the incision may be necessary.

Effectiveness of frailty screening and perioperative team management of colectomy patients aged 80 years or more.

BACKGROUND: We aimed to clarify usefulness of the modified Frailty Index 11 (mFI-11) for assessing risk of postoperative complications (POCs) and effectiveness of perioperative management team (POMT) intervention for improving postoperative status of frail aged patients requiring colorectal cancer (CRC) surgery. METHODS: We compared, retrospectively, surgical outcomes among 151 consecutive CRC surgery patients aged ≥80 years. Patients were grouped by mFI-11 scores and by POMT intervention (vs. no POMT intervention). RESULTS: POCs were more prevalent, postoperative stays were longer, and discharge status was poorer among high-risk (mFI-11 ≥ 3/11) patients without POMT intervention than among low-risk (mFI-11 ≤ 2/11) patients (p = 0.04, p = 0.02, p < 0.01). Multiple POCs occurred less frequently and performance of activities of daily living was better for high-risk patients with (vs. those without) POMT intervention (p = 0.04, p = 0.03). CONCLUSION: POMT intervention appears beneficial for frail aged patients scheduled for CRC surgery.

Long-term outcomes of single-incision versus multiport laparoscopic colectomy for colon cancer: results of a propensity score-based analysis.

BACKGROUND: Long-term outcomes of single-incision laparoscopic colectomy (SILC) for colon cancer (CC), as practiced in real-world settings, especially in relation to disease stage, have not been established. We examined, retrospectively, both short- and long-term outcomes of SILC versus those of multiport laparoscopic colectomy (MPLC) performed for CC in a propensity-score-matched cohort. METHODS: The study involved 263 patient pairs matched 1:1 from among 691 patients who, between January 2008 and May 2014, underwent either SILC or MPLC for a primary solitary CC at our hospital. Short-term and long-term operative outcomes were compared between the two groups. RESULTS: Operation time was the only surgical outcome that varied significantly between the two groups (p = 0.0004). Overall 5-year cancer-specific survival (CSS) in the SILC group was 93.7 (95% CI 89.6-96.2)%, and CSS per pathological stage (I, II and III) was 98.5 (90.0-99.8)%, 96.0 (88.2-98.7)%, and 88.3 (79.6-93.6)%, respectively, whereas overall 5-year CSS in the MPLC group was 93.3 (89.4-95.9)%, and CSS per pathological stage was 100%, 95.4 (88.3-98.3)%, and 84.1 (74.1-90.8)% (p = 0.5278, 0.2679, 0.7666, and 0.9073), respectively. Overall 3-year disease-free survival (DFS) in the SILC group was 94.0 (90.2-96.4)%, and 3-year DFS per pathological stage was 98.6 (90.4-99.8)%, 90.1 (81.4-95.0)%, and 79.0 (69.4-86.2)%, respectively, whereas overall 3-year DFS in the MPLC group was 93.2 (89.4-95.7)%, and 3-year DFS per pathological disease stage was 100%, 94.5 (87.4-97.7)% and 75.5 (64.7-83.8)% (p = 0.2829, 0.7401, 0.4335 and 0.8518), respectively. Thus, oncological outcomes did not differ significantly between groups. Incisional hernia occurred in 21 (8.0%) SILC group patients and 17 (6.5%) MPLC group patients, without a significant between-group difference (p = 0.6139). CONCLUSION: Our data indicate that perioperative and oncological outcomes of SILC performed for CC are comparable to those of MPLC performed for CC.

Circulating MicroRNAs in Gastrointestinal Cancer.

Gastrointestinal cancer (GIC) is a common disease and is considered to be the leading cause of cancer-related death worldwide; thus, new diagnostic and therapeutic strategies for GIC are urgently required. Noncoding RNAs (ncRNAs) are functional RNAs that are transcribed from the genome but do not encode proteins. MicroRNAs (miRNAs) are short ncRNAs that are reported to function as both oncogenes and tumor suppressors. Moreover, several miRNA-based drugs are currently proceeding to clinical trials for various diseases, including cancer. In recent years, the stability of circulating miRNAs in blood has been demonstrated. This is of interest because these miRNAs could be potential noninvasive biomarkers of cancer. In this review, we focus on circulating miRNAs associated with GIC and discuss their potential as novel biomarkers.

Single-port laparoscopic extended right hemicolectomy with complete mesocolic excision and central vascular ligation using a right colon rotation technique (flip-flap method).

INTRODUCTION: Single-port laparoscopic extended right hemicolectomy with complete mesocolic excision and central vascular ligation is technically challenging, and a standardized procedure is needed to minimize technical hazards. TECHNIQUE: As a first step, the hepatic flexure is mobilized from the duodenum, and the third part of the duodenum and pancreatic head was exposed. Next, the ileocecal vessels are divided at the root using a medial-to-lateral approach, and the cecum is separated from the retroperitoneal space. This process completes the mobilization of the right colon. In the second step, the omental bursa is opened, and the inferior border of the pancreas is exposed. The mobilized right colon is turned around to the left of the superior mesenteric vein, continuing to separate the mesentery from right to left side, and the right colic vessels are divided at the roots. The inverted right colon is restored to its original position, and the mesenteric fat is dissected along the left edge of the superior mesenteric artery to the inferior border of the pancreas. RESULTS: A total of 57 consecutive patients with advanced hepatic flexure colon cancer (n = 24) and transverse colon cancer (n = 33) underwent S-ERHC. The conversion rate to open surgery was 5.3%. Operative time, blood loss, and number of harvested lymph nodes were 232 min (interquartile range [IQR], 184-277 min), 5 mL (IQR, 5-66 mL), and 30 (IQR, 22-38), respectively. According to the Clavien-Dindo classification, the grade ≥ 2 complication rate was 10.5%. Median duration of hospitalization was 9 days (IQR, 7-13 days). CONCLUSIONS: Single-port laparoscopic extended right hemicolectomy using a right colon rotation technique is safe, feasible, and useful. This technique of repeating the inversion and restoration of the right colon may help avoid bleeding and damage to other organs and facilitate reliable lymph node dissection.

Risk Factors for Lymph Node Metastasis in Pathological T1b Colorectal Cancer.

BACKGROUND/AIM: The rate of lymph node metastasis (LNM) of colorectal carcinoma (CRC) with a submucosal (SM) invasion depth of 1000 µm or more can reach 12.5%, which is the most common reason for additional resection in daily practice. Other studies have reported that the rate of LNM is less than 2%, regardless of the depth of invasion, if the lesions show good histology, lymphovascular infiltration is negative, and tumor budding is limited. The purpose of this study was to investigate new risk factors for LNM in T1b colorectal cancer. PATIENTS AND METHODS: The 239 patients who were diagnosed with pathological T1b CRC after colorectal surgical resection at the Osaka Police Hospital in Japan between January 2008 and December 2018 were retrospectively reviewed in this study. RESULTS: The LNM rate was 11.3% (27/239). The variables identified as being significant factors using multivariate analysis were: i) lymphatic invasion (Ly)-positive [odds ratio (OR)=5.97; 95% confidence interval (CI)=2.27-15.74], ii) female gender (OR=3.49; 95%CI=1.38-8.85), and iii) left-sided colorectal involvement (OR=4.98; 95%CI=1.22-20.39). If none of these risk factors were present with T1b, the LNM rate was 0% (0/28). CONCLUSIONS: Ly-positive, female gender, and left-sided colorectal involvement could be risk factors for LNM in T1b CRC.

[Effect of Endoscopic Resection on Prognosis in T1b Colorectal Cancer].

With the advancement of endoscopic resection(ER)of colorectal cancer, surgical resection after ER has been increasing. This study evaluated the effects of initial ER on short- and long-term outcomes in T1b colorectal cancer. This retrospective cohort study enrolled patients with pathological T1b colorectal cancer who underwent colorectal surgical resection between 2008 and 2018. A total of 239 eligible patients were divided into 2 groups: patients initially treated using surgical resection with lymph node dissection(LND)(surgery alone, n=142)and patients treated using initial ER and additional surgical resection with LND(surgery after ER, n=97). No significant differences were observed in short-term outcomes(ie, operative time, blood loss, or postoperative complications)or the long-term outcomes(ie, recurrence rate, overall survival rate, or recurrence free survival rate)between groups.