Rare recurrence pattern after complete response to chemotherapy in a patient with rectal cancer: a case report.

BACKGROUND: Colorectal cancer (CRC) often metastasizes to the liver, lungs, lymph nodes, and peritoneum but rarely to the bladder, small intestine, and skin. We here report the rare metastasis of anal cancer in the left bladder wall, followed by metastases to the small intestine and skin, after abdominoperineal resection and left lateral lymph node dissection with chemotherapy in a patient with clinician Stage IVa disease. CASE PRESENTATION: A 66-year-old man presented with 1-month history of bloody stool and anal pain and diagnosed with clinical Stage IVa anal cancer with lymph node and liver metastases (cT3, N3 [#263L], M1a [H1]). Systemic chemotherapy led to clinical complete response (CR) for the liver metastasis and clinical near-CR for the primary tumor. Robot-assisted laparoscopic perineal rectal resection and left-sided lymph node dissection were performed. Computed tomography during 18-month postoperative follow-up identified a mass in the left bladder wall, which was biopsied with transurethral resection, was confirmed as recurrent anal cancer by histopathologic evaluation. After two cycles of systemic chemotherapy, partial resection of the small intestine was performed due to bowel obstruction not responding to conservative therapy. The histopathologic evaluation revealed lymphogenous invasion of the muscularis mucosa and subserosa of all sections. Ten months after the first surgery for bowel obstruction and two months before another surgery for obstruction of the small intestine, skin nodules extending from the lower abdomen to the thighs were observed. The histopathologic evaluation of the skin biopsy specimen collected at the time of surgery for small bowel obstructions led to the diagnosis of skin metastasis of anal cancer. Although panitumumab was administered after surgery, the patient died seven months after the diagnosis of skin metastasis. CONCLUSIONS: This case illustrates the rare presentation of clinical Stage IVa anal cancer metastasizing to the bladder wall, small intestine, and skin several years after CR to chemotherapy.

[A Case of Conversion Surgery for Unresectable Advanced Gastric Cancer of Which Metastatic Site Was Disappear by Chemotherapy but the Primary Site Was Enlarged after Five Years].

A 77-year-old man presented to our hospital with a chief complaint of stomachache. He received a diagnosis of unresectable advanced gastric cancer classified as cT3, N+, M1(LYM, HEP, OSS), Stage ⅣB. He underwent first-line chemotherapy with SOX, second-line treatment with PTX plus Ram, and third-line treatment with nivolumab. The primary tumor showed a reduction in size, and liver and lymph node metastases were not detectable. However, after 5 years of chemotherapy, a re- enlargement was observed in the primary gastric lesion without progression of liver and lymph node metastases. Subsequently, conversion surgery was performed. Based on the pathological analysis, the diagnosis was ypT1b2(SM2), N0(0/17), M0, ypStage ⅠA, R0. After nivolumab administration postoperatively for 5 months, chemotherapy was discontinued as there was no recurrence.

Three-year progression-free survival of a patient with concomitant mucinous adenocarcinoma of the colon with peritoneal dissemination and multiple myeloma who received lenalidomide: a case report.

BACKGROUND: Concomitant multiple myeloma (MM) and other primary malignancies is rare. Therefore, the treatment outcomes of patients with these conditions have not been well discussed. Lenalidomide is an oral thalidomide analog drug used for MM. Recently, the antitumor effect of lenalidomide has been gaining attention, and lenalidomide has been applied for managing solid tumors. The current case showed the treatment course of a patient treated with lenalidomide for concomitant MM and colon cancer with peritoneal dissemination. CASE PRESENTATION: A 74-year-old female patient receiving treatment for MM was diagnosed with mucinous adenocarcinoma of the transverse colon. The patient was clinically diagnosed with stage IIIC T4aN2M0 disease. Subsequently, laparoscopic colectomy with lymph node dissection was planned. However, intraperitoneal observation revealed peritoneal dissemination that had sporadically and widely spread. Therefore, palliative partial colectomy was performed to prevent future hemorrhage or obstruction. The patient was discharged on the 10th postoperative day without postoperative complication. Based on the patient's preference, lenalidomide was continually administered for MM without systemic chemotherapy. The patient survived for > 36 months without any signs of tumor progression. CONCLUSION: The current case first showed the treatment course of concomitant MM and colon cancer. The antitumor effect of lenalidomide can possibly contribute to 3-year progression-free survival in patients with mucinous adenocarcinoma of the colon with peritoneal dissemination.

Clinical Impact of Transanal Drainage Tube on Anastomosis Leakage Following Minimally Invasive Resection Without Diverting Stoma in Patients With Rectal Cancer: A Propensity Score-matched Analysis.

OBJECTIVES: As one of the most serious complications of rectal cancer (RC) surgery, preventing anastomotic leakage (AL) is crucial. Several studies have suggested a positive role of the transanal drainage tube (TaDT) in AL prevention. However, whether TaDT is beneficial for AL in patients with RC remains controversial. The present study aimed to evaluate the clinical impact of TaDT on AL following minimally invasive resection without diverting stoma (DS) in patients with RC. MATERIALS AND METHODS: We retrospectively analyzed 392 consecutive patients with RC who had undergone minimally invasive resection without DS between 2010 and 2021. Propensity score matching (PSM) was performed to reduce selection bias. AL was classified as grade A, B, or C. RESULTS: A TaDT was used in 214 patients overall. After PSM, we enrolled 316 patients (n=158 in each group). Before PSM, significant group-dependent differences were observed in terms of age, American Society of Anesthesiologists physical status, and the use of antiplatelet/anticoagulant agents. The frequency of AL was 7.3% in the overall cohort and was significantly lower in the TaDT group (3.7%) than in the non-TaDT group (11.8%). The rate of grade B AL was significantly lower in the TaDT group than in the non-TaDT group (before PSM, P <0.01; after PSM, P =0.02). However, no significant differences between groups were found for grade C AL. Moreover, multivariate analysis identified the lack of a TaDT as an independent risk factor for AL in the overall and matched cohorts [before PSM, odds ratio, 3.64, P <0.01; after PSM, odds ratio, 2.91, P =0.02]. CONCLUSION: These results indicated that TaDT may play a beneficial role in preventing AL, particularly of grade B, for patients with RC undergoing minimally invasive resection without DS. However, further randomized controlled trials, including patient-reported outcomes, are still needed to understand better the role of TaDT in preventing ALs in patients with RC undergoing minimally invasive resection without DS.

Impact of regional lymph node metastasis on pulmonary metastasis as the first recurrence site.

Little is known about the impact of regional lymph node metastasis (LNM) on the first recurrence sites following curative colorectal cancer (CRC) surgery. The present study aimed to clarify the relationship between regional LNM stratified by N status and the first recurrence pattern in patients with stage I-III CRC. We performed a retrospective analysis of 1181 consecutive patients with stage I-III CRC who underwent curative surgery between 2010 and 2018. The total sample size included 1181 patients who underwent elective stage I-III CRC surgery. Median follow-up time was 60 months, and median time to recurrence was 12 months. Overall, the numbers of liver recurrence and pulmonary recurrence were 94 (7.9%) and 70 (5.9%), respectively. Higher N status was significantly associated with increased risk of pulmonary recurrence (N0 vs. N1a, p = 0.02; N0 vs. N1b, p < 0.01; N0 vs. N2a, p < 0.01; N0 vs. N2b, p < 0.01) and worse pulmonary recurrence-free survival, but not other recurrences. In Non-LNM patients, on the other hand, advanced T status was associated with increased risk of pulmonary recurrence. The regional LNM was strongly associated with pulmonary metastasis as the first recurrence site following stage I-III CRC resection.

Aggressive surgical intervention may improve prognosis in patients with ovarian metastasis from colorectal cancer.

PURPOSE: The current study aimed to investigate the prognostic clinicopathological factors of synchronous and metachronous ovarian metastasis (OM) from colorectal cancer (CRC) in patients with and without oophorectomy. METHODS: Female patients with OM from CRC who underwent primary tumor resection at our institution from January 2013 to December 2020 were evaluated. RESULTS: Of 661 female patients, 22 (3.3%) were diagnosed with OM. Among 22 patients with OM, 12 underwent OM resection. Twenty (91%) patients had extra OM upon diagnosis. Thirteen (59%) patients in the non-surgery group had peritoneal dissemination at surgery or on computed tomography scan or positron emission tomography-computed tomography. Two patients in the OM surgery group had emergency surgery because of abdominal pain. Four patients had postoperative complications, and the median duration of hospital admission was 16.5 days. The median survival time from OM diagnosis to mortality was 20.9 months. Then, the association between the clinicopathological factors and overall survival (OS) was investigated. Tumor location and surgery were found to be related to OS (p = 0.03, 0.006, respectively) in the univariate analysis. However, only surgery was associated with OS (p = 0.02) in the multivariate analysis. CONCLUSION: Surgery is an important prognostic clinicopathological factor of OM from CRC. OM tumors should be resected because OM surgery is less likely to cause complications and symptoms.

Single-incision laparoscopic surgery for intestinal intussusception due to neuroendocrine tumor.

BACKGROUND: Small intestinal neuroendocrine tumor (NET) is uncommon, but intestinal intussusception caused by NET is even rare. We report a rare case of single-incision laparoscopic surgery (SILS) for intestinal intussusception due to NET G1. CASE PRESENTATION: A 72-year-old woman presented with vomiting, diarrhea, and abdominal pain. Contrast-enhanced computed tomography (CT) revealed the target sign in the ascending colon. An enhanced nodule was detected at the lead point, leading us to suspect a tumor. Colonoscopy showed a tumor at the lead point of the intestinal intussusception. Histological findings led to a diagnosis of NET G1. Single-incision laparoscopic ileocecal resection with regional lymphadenectomy was then performed. The patient was discharged 10 days postoperatively with no complications. CONCLUSION: We achieved SILS with regional lymphadenectomy for preoperatively diagnosed intestinal intussusception due to NET G1. Although this condition is rare, surgeons should take this possibility into consideration in cases showing similar findings.

[A Case of Advanced Gastric Cancer in Which Tumor Relapse Was Observed after Discontinuation of Nivolumab Due to Complete Response, and for Which Re-Administration Was Initiated].

A 61-year-old male was diagnosed with unresectable advanced gastric cancer(cT4b[SI; panc], N+, M0, cStage ⅣA). However he was administered S-1 plus oxaliplatin as a primary treatment and ramucirumab plus paclitaxel as a secondary treatment, the primary tumor and lymph nodes were enlarged. We judged PD and switched to the third-line treatment with nivolumab. After starting nivolumab, both the primary tumor and the lymph nodes shrank, and the PET-CT scan after 24 courses showed no FDG accumulation in the primary tumor or lymph nodes, so we judged the response as CR. The patient requested discontinuation of nivolumab, and nivolumab administration was stopped. Twenty months later after nivolumab administration was discontinued, CT scan showed re-growth of the primary tumor, and nivolumab administration was resumed. After resumption, he received 22 courses of nivolumab for 10 months with maintenance of SD.

Laparoscopic Right Hemicolectomy With Complete Mesocolic Excision and Central Vascular Ligation Using a Right Colon Rotation Technique (Flip-Flap Method).

Background: Laparoscopic right hemicolectomy (Lap-RHC) with complete mesocolic excision (CME) and central vascular ligation (CVL) is technically challenging. A standardized procedure is thus needed to minimize technical hazards. Technique: We have developed the "flip-flap method," comprising repeated inversion and restoration of the mobilized right colon according to the anatomical complexity and vascularity in Lap-RHC, and showed that this technique is safe, feasible, and useful in terms of CME and CVL. Our study included 30 consecutive patients who underwent Lap-RHC using the flip-flap method between April 2018 and December 2020. The short-term surgical outcomes suggested this method was safe and feasible. We report herein the surgical procedure for this flip-flap method. The hepatic flexure is mobilized, then the ileocecal vessels are divided, and the cecum is separated from the retroperitoneal space. The mobilized right colon is rotated to the left of the superior mesenteric vein, continuing to separate the mesentery from right to left, and the right colic vessels are divided. If division of the right colic vessels is technically difficult, the inverted right colon is restored to its original position, and the right colon vessels are divided. Finally, the transverse mesenteric fat is dissected along the left edge of the superior mesenteric artery to the inferior border of the pancreas. Conclusions: We consider that the most useful point of this technique is the ability to develop an optimal operative field according to the anatomical complexity and vascularity of the individual, securing CME without unexpected bleeding or damage to other organs.

Identification of the Minimum Combination of Serum microRNAs to Predict the Recurrence of Colorectal Cancer Cases.

BACKGROUND: Serum microRNAs (miRNAs) have been recognized as potential stable biomarkers for various types of cancer. Considering the clinical applications, there are certain critical requirements, such as minimizing the number of miRNAs, reproducibility in a longitudinal clinical course, and superiority to conventional tumor markers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9. This study aimed to identify serum miRNAs that indicate the recurrence of colorectal cancer (CRC), surpassing inter-tumor heterogeneity. METHODS: We conducted an analysis of 434 serum samples from 91 patients with CRC and 71 healthy subjects. miRNAs were obtained from Toray Co., Ltd, and miRNA profiles were analyzed using a three-step approach. miRNAs that were highly expressed in patients with CRC than in the healthy controls in the screening phase, and those that were highly expressed in the preoperative samples than in the 1-month postoperative samples in the discovery phase, were extracted. In the validation phase, the extracted miRNAs were evaluated in 323 perioperative samples, in chronological order. RESULTS: A total of 12 miRNAs (miR-25-3p, miR-451a, miR-1246, miR-1268b, miR-2392, miR-4480, miR-4648, miR-4732-5p, miR-4736, miR-6131, miR-6776-5p, and miR-6851-5p) were significantly concordant with the clinical findings of tumor recurrence, however their ability to function as biomarkers was comparable with CEA. In contrast, the combination of miR-1246, miR-1268b, and miR-4648 demonstrated a higher area under the curve (AUC) than CEA. These three miRNAs were upregulated in primary CRC tissues. CONCLUSION: We identified ideal combinatorial miRNAs to predict CRC recurrence.

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.

Oncological outcomes following minimally invasive surgery for pathological N2M0 colorectal cancer: A propensity score-matched analysis.

INTRODUCTION: Whether minimally invasive surgery (MIS) is safe and effective for patients with N2M0 colorectal cancer (CRC) remains controversial. This study aimed to compare short- and long-term outcomes between MIS and open surgery (Open) groups for patients with pathological (p)N2M0 CRC, and evaluate the oncological outcomes of MIS for pN2M0 CRC. MATERIALS AND METHODS: We retrospectively analyzed 125 consecutive patients with pN2M0 CRC who underwent curative surgery between 2010 and 2017, using propensity score-matching (PSM) analysis. RESULTS: Median follow-up was 59.4 months. After PSM, we enrolled 68 patients (n = 34 in each group). The conversion rate was 9.6% for the entire patient cohort and 5.9% for the matched cohort. In colon cancer (CC), short-term outcomes were similar between groups. On the other hand, in rectal cancer (RC), estimated blood loss, rate of anastomosis leakage, and length of postsurgical stay were lower in the MIS group than the Open group. R0 resection was achieved in all patients with MIS. No surgical mortality was encountered in any group. No significant differences were found between groups in terms of 3-year local recurrence rate, overall survival, cancer-specific survival, or recurrence-free survival among the entire patient cohort or the matched cohort, regardless of the primary tumor site (CC or RC). Surgical approach (MIS vs Open) had no significant influence on survival outcomes. CONCLUSIONS: MIS is a safe and effective option for patients with pN2M0 CRC, with acceptable short- and long-term outcomes comparable to the open approach. MIS can be considered for patients with pN2M0 CRC.

A case in which the ileocolic vein draining into the gastrocolic trunk of Henle could be diagnosed preoperatively: a rare anatomical case report.

BACKGROUND: Numerous variations in vascular anatomy have been reported in the right colon. The ileocolic vein (ICV) generally drains directly into the superior mesenteric vein (SMV), and is an important landmark for laparoscopic surgery in right colon cancer. We present here a patient with a vascular anomaly of the ICV that was diagnosed on preoperative imaging. CASE PRESENTATION: A 65-year-old woman was diagnosed with transverse colon cancer by colonoscopy. Preoperative computed tomography scan showed that the ICV drained into the gastrocolic trunk of Henle (GCT) rather than the SMV. Single-incision laparoscopic transverse colectomy with D3 lymph node dissection was performed, dividing the middle colic vein (MCV) and preserving the right gastroepiploic vein (RGEV), anterior superior pancreaticoduodenal vein (ASPDV), GCT and ICV. The intraoperatively identified venous anatomy was consistent with the preoperative evaluation, and the RGEV, ASPDV and ICV were found to form the GCT. CONCLUSION: We report a rare vascular anatomical anomaly that was diagnosed preoperatively, facilitating safe and successful single-incision laparoscopic surgery with D3 lymph node dissection.

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.

Impact of antithrombotic agents on short-term outcomes following minimally invasive colorectal cancer surgery: a propensity score-matched analysis.

BACKGROUND: It remains unclear whether minimally invasive colorectal cancer (CRC) surgery under the suitable management of perioperative antithrombotic therapy (ATT) is safe and feasible in patients treated with chronic ATT. The present study aimed to assess the impact of ATT on short-term outcomes following minimally invasive CRC surgery. METHODS: We retrospectively analyzed 1495 consecutive patients who underwent elective minimally invasive CRC surgery between 2011 and 2021, using propensity score-matched analysis. RESULTS: Overall, 230 patients had chronically received ATT. After propensity score matching, we enrolled 412 patients (n = 206 in each group). Before matching, significant group-dependent differences were observed in terms of sex (p < 0.01), age (p < 0.01), American Society of Anesthesiologists' physical status (p < 0.01), body mass index (p < 0.01), and pathological N classification (p = 0.03). The frequencies of overall postoperative complications, bleeding events, and thromboembolic events were significantly higher in the ATT group than in the Non-ATT group (p < 0.01). After matching, no significant differences were found between the groups in terms of clinical or surgical characteristics, or in terms of the frequency of overall postoperative complications, bleeding events, thromboembolic events, length of postoperative stay, or any other postoperative complication. Multivariate analysis identified no significant risk factors for postoperative bleeding events or severe postoperative complications associated with ATT. CONCLUSIONS: Patients treated with chronic ATT showed acceptable short-term outcomes for minimally invasive CRC surgery compared with those not receiving ATT. Minimally invasive CRC surgery appears safe and feasible under the suitable management of perioperative ATT regardless of whether the patient has a history of ATT.

Impact of prior abdominal surgery on short-term outcomes following laparoscopic colorectal cancer surgery: a propensity score-matched analysis.

BACKGROUND: Whether laparoscopic surgery after prior abdominal surgery (PAS) is safe and feasible for colorectal cancer (CRC) remains controversial. The present study aimed to evaluate the impact of PAS on short-term outcomes following laparoscopic CRC surgery. METHODS: We performed retrospective analysis used propensity score-matched analysis to reduce the possibility of selection bias. Participants comprised 1284 consecutive patients who underwent elective laparoscopic CRC surgery between 2010 and 2020. Patients were divided into two groups according to PAS. Patients with PAS were then matched to patients without these conditions. Short-term outcomes were evaluated between groups in the overall cohort and matched cohort, and risk factors for conversion to laparotomy and severe postoperative complications were analyzed. RESULTS: After propensity score matching, we enrolled 762 patients (n = 381 in each group). Before matching, significant group-dependent differences were observed in sex, age, primary tumor site, pathological (p) T stage, and type of procedure. No significant difference was found between groups in terms of rate of conversion to laparotomy, estimated blood loss, rate of extended resection, length of postoperative stay, and postoperative complications. After matching, estimated operative time was significantly longer in the PAS group (p = 0.01). Significant differences were found between groups in terms of reason for conversion to laparotomy. Multivariate analyses identified significant risk factors for conversion to laparotomy as pT stage ≥ 3 (odds ratio [OR] 2.36; 95% confidence interval [CI] 1.05-5.26) and body mass index ≥ 25 kg/m2 (OR 3.56; 95% CI 1.07-11.7). Multivariate analyses identified rectum in the primary tumor site as the only significant risk factor for severe postoperative complications (OR 2.37; 95% CI 1.08-5.20). CONCLUSIONS: Laparoscopic CRC surgery after PAS showed acceptable short-term outcomes compared to Non-PAS. The laparoscopic approach appears safe and feasible for CRC regardless of whether the patient has a history of PAS.

Short-term outcomes of robotic-assisted versus conventional laparoscopic-assisted surgery for rectal cancer: a propensity score-matched analysis.

It remains controversial whether the advantages of robotic-assisted surgery are beneficial for rectal cancer (RC). The study aimed to evaluate the short-term outcomes of robotic-assisted rectal surgery (RARS) compared with those of conventional laparoscopic-assisted rectal surgery. We retrospectively analyzed 539 consecutive patients with stage I-IV RC who had undergone elective surgery between January 2010 and December 2020, using propensity score-matched analysis. After propensity score matching, we enrolled 200 patients (n = 100 in each groups). Before matching, significant group-dependent differences were observed in terms of age (p = 0.04) and body mass index (p < 0.01). After matching, clinicopathologic outcomes were similar between the groups, but estimated operative time was longer and postoperative lymphorrhea was more frequent in the RARS group. Estimated blood loss, rate of conversion to laparotomy, and incidence of anastomotic leakage or reoperation were significantly lower in the RARS group. No surgical mortality was observed in either group. No significant differences were observed in terms of positive resection margins or number of lymph nodes harvested. RARS was safe and technically feasible, and achieved acceptable short-term outcomes. The robotic technique showed some advantages in RC surgery that require validation in further studies.

Pan-cancer methylome analysis for cancer diagnosis and classification of cancer cell of origin.

The accurate and early diagnosis and classification of cancer origin from either tissue or liquid biopsy is crucial for selecting the appropriate treatment and reducing cancer-related mortality. Here, we established the CAncer Cell-of-Origin (CACO) methylation panel using the methylation data of the 28 types of cancer in The Cancer Genome Atlas (7950 patients and 707 normal controls) as well as healthy whole blood samples (95 subjects). We showed that the CACO methylation panel had high diagnostic potential with high sensitivity and specificity in the discovery (maximum AUC = 0.998) and validation (maximum AUC = 1.000) cohorts. Moreover, we confirmed that the CACO methylation panel could identify the cancer cell type of origin using the methylation profile from liquid as well as tissue biopsy, including primary, metastatic, and multiregional cancer samples and cancer of unknown primary, independent of the methylation analysis platform and specimen preparation method. Together, the CACO methylation panel can be a powerful tool for the classification and diagnosis of cancer.

[Outcome of Hepatectomies for Non-Colorectal Liver Metastases].

We performed 16 cases of non-colorectal liver metastasis resection(19 resections)between January 2011 and December 2021. Among the 16 cases, the primary lesions were as follows: gastric cancer in 7 cases; GIST in 2 cases; and neuroendocrine tumor, renal cancer, pancreatic cancer(acinic cell carcinoma), cholangiocarcinoma, breast cancer, ovarian cancer, and leiomyosarcoma in 1 case each. The median time from primary lesion resection to the diagnosis of liver metastasis was 20.6 months. In cases of neuroendocrine tumors and renal cancer, hepatectomy was performed with a preoperative diagnosis of hepatocellular carcinoma. Four cases underwent laparoscopic hepatectomy, and 10 cases underwent anatomical liver resection. Postoperative chemotherapy was performed in 8 cases. Recurrence of liver metastasis was observed in 7 cases. One case of gastric cancer and 1 case of neuroendocrine tumor underwent repeat hepatectomy. The median relapse-free survival was 13.8 months, and the median overall survival was 55.7 months.

[A Case of Synchronous Secondary Lymph Node Metastasis in the Mesentery of the Ileum with cCR Achievement after Surgery for Sigmoid Colon Cancer].

A 71-year-old woman was hospitalized with loose stools and lightheadedness. She was subsequently diagnosed with sigmoid colon cancer for which we performed a laparoscopic sigmoid colectomy, small intestine partial resection, partial bladder resection, and open conversion. The intraoperative findings and histopathological analysis showed secondary lymph node metastasis in the mesentery of the ileum, and the surgery resulted in R2 resection. Chemotherapy(CAPOX plus Bev) was initiated thereafter, and the L-OHP and Bev were discontinued over time. A complete response was achieved at 1 year postoperative. Capecitabine alone was continued, and no signs of recurrence were noted at 2 years postoperative.