Prognosis and predictive factors of conversion surgery for initially unresectable advanced colorectal cancer.

PURPOSE: The aim of this study was to report the outcomes of conversion surgery for initially unresectable advanced colorectal cancer and to identify factors that enable successful conversion surgery. METHODS: We compared the outcomes of patients with colorectal cancer with distant metastases, including extrahepatic metastases, who underwent upfront surgery, neoadjuvant chemotherapy, conversion surgery, and chemotherapy only at our department from 2007 to 2020. In addition, factors influencing the achievement of conversion surgery in patients who were initially unresectable were examined in univariate and multivariate analyses. RESULTS: Of 342 colorectal cancer patients with distant metastases treated during the study period, 239 were judged to be initially unresectable, and 17 (conversion rate: 7.1%) underwent conversion surgery. The prognosis for the conversion surgery group was better than that of the chemotherapy only group but worse than that of the upfront surgery group. In the conversion surgery group, the recurrence-free survival after resection was significantly shorter than that upfront surgery group and neoadjuvant chemotherapy group, and no patients have been cured. Among patients who were initially unresectable, left-sided primary cancer and normal CA19-9 level were identified as independent factors contributing to the achievement of conversion surgery in a multivariate analysis. CONCLUSIONS: Although relapse after conversion surgery is common, and no patients have been cured thus far, overall survival was better in comparison to patients who received chemotherapy only. Among unresectable cases, patients with left-sided primary cancer and normal CA19-9 levels are likely to be candidates for conversion surgery.

Analysis of patients with colorectal cancer shows a specific increase in serum anti-ING1 autoantibody levels.

Colorectal cancer (CRC) is the third most prevalent cancer in the world, yet the sensitivity and specificity of biomarkers for CRC diagnosis are insufficient. In the present study, we performed a protein microarray screening method to identify antibody markers for CRC. Inhibitor of growth family 1 (ING1) was identified as a candidate tumor antigen for CRC using protein microarrays (ProtoArray). Subsequent amplified luminescence proximity homogeneous assay-linked immunosorbent assay using recombinant ING1 protein showed that the serum levels of anti-ING1 antibodies were increased not only in patients with CRC but also in those with esophageal cancer (EC), gastric cancer (GC), breast cancer (BrC), and pancreatic cancer (PC) compared with those of healthy donors (HDs). Antibodies against the ING1 amino acids between 239 and 253 were present at significantly higher levels in patients with CRC than in those with EC, GC, BrC, or PC. Anti-ING1 antibody levels were significantly higher in the patients with CRC at any stages than in the HDs. Immunohistochemical staining revealed higher expression of ING1 protein in CRC cells than in the adjacent normal tissues. In luciferase reporter assays using a CRC cell line, ING1 augmented p53-mediated NOXA promoter activity but attenuated p53-stimulated Bax, p21, and PUMA promoter activities. Consequently, serum anti-ING1 antibodies can be used for sensitive and specific diagnoses of CRC.

[A Case of Primary Duodenal Adenocarcinoma in the Third Portion Treated with Partial Duodenectomy and Adjuvant Chemotherapy].

A 69-year-old man was referred for vomiting. CT and upper gastrointestinal endoscopy revealed a circumferential stenotic lesion in the third portion of the duodenum, and partial duodenectomy and lymph node dissection were performed for the diagnosis of duodenal adenocarcinoma. The histopathological diagnosis was pT3, pN0, pStage ⅡA(UICC 8th)well differentiated tubular adenocarcinoma. The patient was treated with FOLFOX as adjuvant chemotherapy and is alive 2 years and 4 months postoperatively without recurrence. Primary duodenal adenocarcinoma in the third portion is rare, and further case experience is required for selection of the operation and adjuvant therapy.

[A Case of Resection of Overlapping Ascending Colon Cancer and Primary Malignant Lymphoma of the Cecum].

The patient was a 90-year-old man. He was referred to our department with a diagnosis of ascending colon cancer after lower gastrointestinal endoscopy for a positive stool occult blood test. Lower gastrointestinal endoscopy revealed a type 1 tumor 30 mm in the ascending colon and a type 3 tumor 50 mm in the cecum. Biopsy revealed Group 5(tub1)for the ascending colon lesion, but Group 2 for the cecum lesion. The patient was clinically diagnosed as having overlapping ascending colon cancer and cecum cancer, and a right hemicolectomy of the colon was performed. Histopathological examination revealed ascending colon cancer and primary malignant lymphoma of the cecum.

[A Case of Postoperative Lymph Node Metastatic Recurrence of Ascending Colon Cancer Invading the Primary Branch of Superior Mesenteric Artery during Hemodialysis].

A 58-year-old man with chronic renal disease underwent ileo-cecal resection with lymph node dissection for cancer of the ascending colon at his previous physician. The pathological diagnosis was pT3N0M0, pStage Ⅱa. One year and 7 months after surgery, he was diagnosed with local and lymph node recurrence and referred to our department. Contrast- enhanced CT revealed that an irregular nodal shadow 25 mm in size adjacent to the superior mesenteric artery and the transvers part of duodenum, which was suspicious for lymph node recurrence. We regarded this patient as marginally resectable and neoadjuvant treatment was considered, but because the patient was on dialysis, we decided to operate without pre-operative treatment. Surgical findings showed invasion of a recurrent lymph node into a primary branch of the superior mesenteric artery and vein. We temporarily blocked these vessels and cut off these vessels after checking that blood flow in the intestine was maintained by intravenous injection of ICG. The lymph node was also invading the uncinate process of the pancreas and the transvers part of duodenum, we performed partial resection of those organs. Pathology revealed no tumor exposure on the dissected surface and R0 resection was achieved. The patient received 5 courses of postoperative folinate/ uracil/tegafur therapy and is alive 1 year postoperatively without recurrence.

Oral antibiotics and a low-residue diet reduce the incidence of anastomotic leakage after left-sided colorectal surgery: a retrospective cohort study.

PURPOSE: Anastomotic leakage is a potential complication after colorectal surgery. We investigated the effects of oral antibiotics and a low-residue diet on the incidence of anastomotic leakage after left-sided colorectal surgery. METHODS: Outcomes were retrospectively compared between 64 patients who underwent mechanical bowel preparation alone (group A) and 183 patients who underwent mechanical bowel preparation with addition of oral kanamycin and metronidazole (group B) on the day before left-sided colorectal surgery. After surgery, patients in group A received a normal diet containing dietary fiber and those in group B received a low-residue diet. The primary outcome was the incidence of anastomotic leakage. Secondary outcomes were rates of other postoperative complications, length of postoperative hospital stay, and laboratory data. RESULTS: Anastomotic leakage, surgical site infection, and diarrhea were less common in group B than in group A (4.9% vs 18.8%, 6.6% vs 23.4%, and 25.7% vs 43.8%, respectively). Postoperative C-reactive protein levels were significantly lower in group B. The median postoperative hospital stay was significantly shorter in group B than in group A (8 days vs 9 days, P = 0.010). Adaptive double least absolute shrinkage and selection operator regression revealed that use of preoperative oral antibiotics and a postoperative low-residue diet were associated with lower incidence of anastomotic leakage (odds ratio 0.163, 95% confidence interval 0.062-0.430; P < 0.001). CONCLUSION: Oral antibiotics and a low-residue diet reduced the incidence of anastomotic leakage and shortened the postoperative hospital stay by 1 day.

Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke.

BACKGROUND: Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS. METHODS: Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay. RESULTS: The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297-311 of DIDO1, 426-440 of FOXJ2, and 607-621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case-control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS. CONCLUSIONS: Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

Clinical utility of transanal indocyanine green near-infrared fluorescence imaging for evaluation of colorectal anastomotic perfusion.

BACKGROUND: Although indocyanine green (ICG) fluorescence imaging has been reported to be useful for assessing colorectal perfusion, unstable quantification remains an issue. We performed ICG fluorescence observation from the luminal side and examined the usefulness of the transanal approach. METHODS: A total of 69 patients who underwent left-side colon surgery were enrolled in this cohort study. After the anastomosis had been constructed, ICG 0.2 mg/kg was injected intravenously. The anastomotic site was then observed by a scope inserted transanally. The following items were examined in the areas of the anastomotic site with the highest- and lowest-fluorescence intensity: maximum fluorescence (Fmax), time from ICG injection to Fmax (Tmax), time from start of dyeing to Fmax (ΔT), and the contrast pattern of the mucosa. RESULTS: Anastomotic leakage (AL) occurred in nine cases. Tmax and ΔT values of the lowest-fluorescence area in the distal intestine showed significant differences in the cases with AL (P = 0.015 and P = 0.040, respectively). Regarding the contrast pattern of the mucosa of the lowest-fluorescence area in the proximal and distal intestine, the patients in whom the vessels were not depicted in the area had a significantly higher incidence of AL than those in whom vessels were depicted in the area (P = 0.031 and P = 0.030, respectively). Some of the areas in which vessels were not depicted by ICG fluorescence observation from the luminal side corresponded to the points of leakage. There were heterogeneous changes that might not be grasped by observation from the serosal side. CONCLUSION: Transanal ICG fluorescence imaging can evaluate perfusion over the entire circumference of the anastomosis in detail and aid in assessing the risk of AL. Therefore, the examination of the detailed low-perfusion area enables us to take measures for AL and to search for safer operative managements.

[Long-Term Control of Metastatic Colon Cancer by Chemotherapy in a Patient on Hemodialysis].

A 54-year-old man receiving dialysis for diabetic nephropathy underwent surgery for sigmoid cancer. Nine months later, he was diagnosed with multiple liver metastases. He underwent 2 courses of FOLFIRI plus panitumumab(Pmab)as first-line therapy, 15courses of capecitabine plus bevacizumab(Bmab)as second-line therapy, and 27 courses of Pmab as third-line therapy. He developed various complications throughout the disease course, such as heart disease, diabetic gangrene in both legs, and abscess of liver metastasis. The tumor marker levels after each event were higher than the previous event and subsequently decreased with the resumption of chemotherapy. However, after 27 courses of Pmab, his liver and para-aortic lymph node metastases exacerbated, and he ultimately died from a poor general condition at 42 months after the initial recurrence of liver metastasis. Evidence regarding the safety and pharmacokinetics of chemotherapy in dialysis patients is insufficient at present. Herein, we report a case of metastatic colon cancer in a patient on hemodialysis along with a literature review.

Histone Demethylase LSD1 Inhibitors Prevent Cell Growth by Regulating Gene Expression in Esophageal Squamous Cell Carcinoma Cells.

BACKGROUND: The expression of genes can be influenced by the balance of histone acetylation and/or histone demethylation, with an imbalance of these processes possibly observed in many cancers. The histone demethylase LSD1 inhibitor activity is associated with selective transcriptional regulation and alterations in the gene expression. However, the exact mechanisms underlying the antitumor effects of LSD1 inhibitors are not fully understood. METHODS: The antitumor effects of NCL1, an LSD1 inhibitor, in esophageal squamous cell cancer (ESCC) cell lines were evaluated. A comprehensive analysis of the changes in the gene expression in ESCC cell lines induced by NCL1 was carried out using a microarray analysis. A loss-of-function assay using a siRNA analysis was performed to examine the oncogenic function of the gene. RESULTS: NCL1 strongly inhibited the cell growth of T.Tn and TE2 ESCC cells and induced apoptosis. According to the microarray analysis, 81 genes in the T.Tn cells and 149 genes in the TE2 cells were up- or down-regulated 2-fold or more by NCL1 exposure. Among these genes, 27 were contained in both cell lines and exhibited similar expression patterns. PHLDB2, one of the genes down-regulated by NCL1, was overexpressed in the ESCC tumor tissues. Moreover, a high expression level of PHLDB2 was found to be significantly correlated with poor prognosis. CONCLUSIONS: The present observations of the comprehensive analysis of the gene expression levels provide insight into the mechanisms underlying the antitumor effects of LSD1 inhibitors in ESCC patients.

Giant esophageal gastrointestinal stromal tumor: report of a case.

Gastrointestinal stromal tumors (GISTs) rarely arise in the esophagus, where carcinoma is the most common malignant neoplasm and leiomyoma is the most common benign tumor. Because of their rarity, the clinical course and treatment of esophageal GISTs are poorly understood. These lesions are generally thought to carry a poor prognosis, making the differential diagnosis of other common mesenchymal neoplasms essential, for both prognostic and therapeutic reasons. We report a case of successfully resected giant esophageal GIST, thought to be the largest resected GIST reported in Japan. The patient was a 65-year-old woman, in whom upper gastrointestinal endoscopy found a 180-mm submucosal tumor in the lower thoracic esophagus, extending just below the aortic arch. We diagnosed esophageal GIST, and the patient underwent middle and lower esophagectomy via left thoracotomy, followed by gastric tube reconstruction. The tumor was resected completely. Histopathological and immunohistochemical staining confirmed that the tumor was a high-risk lesion, and treatment with imatinib was initiated. Computed tomography showed liver metastasis 5 months later, but the patient is doing well 24 months after surgery.

Screening of alternative drugs to the tumor suppressor miR-375 in esophageal squamous cell carcinoma using the connectivity map.

OBJECTIVE: The aim of this study was to identify alternative compounds to the tumor suppressor miR-375 using the connectivity map (CMAP) and to validate the antitumor effects of the identified drugs in esophageal squamous cell carcinoma (ESCC). METHODS: Gene profiling of miR-375-treated TE2 and T.Tn cells was applied in order to search the CMAP database. Among the compounds identified using the CMAP, we focused on 8 drugs [(-)-epigallocatechin-3-gallate, metformin, rosiglitazone among others], excluding 2 drugs among the top 10 compounds. We evaluated whether these compounds possess tumor-suppressive functions in ESCC. RESULTS: A cytotoxicity assay showed that the sensitivity of TE2 and T.Tn cells treated with the 8 compounds was evaluated based on IC50 values of 42.9 µM to 3.8 mM. A cell cycle analysis revealed that the percentage of TE2 and T.Tn cells incubated with 6 compounds in the G0/G1 phase or the G2/M phase increased by approximately 40-80%. A TUNEL assay showed that the percentages of apoptotic cells treated with almost all compounds were significantly increased (p < 0.05) compared with the control cells. CONCLUSION: The CMAP database is a useful tool for identifying compounds affecting the same molecular pathways, particularly products that are difficult to apply via practical approaches, such as microRNAs.

A case of rectal metastasis of prostate cancer mimicking extramural growth-type rectal tumor.

Rectal metastases of prostate cancer are rare and may be difficult to diagnose. In this report, we describe a case in which an extramural growth-type rectal tumor was resected and pathologically diagnosed as prostate cancer metastasis. A 70-year-old man on hormone therapy for prostate cancer with seminal vesicle invasion and pelvic lymph node metastasis was referred to our department after an imaging scan showed an extramural growth-type rectal tumor. Endoscopic ultrasound-guided fine needle aspiration was considered for diagnosis, but the patient preferred an early resection without the exam, so surgery was performed. Histopathological examination revealed that the lesion was in the adventitia of the rectum and metastasis of prostate cancer. Metastatic lesions of prostate cancer are not indicated for resection. A detailed preoperative study with the possibility of prostate cancer metastasis in mind is necessary because it is relevant to choosing the treatment strategy.

The overall prevalence of metastasis in T1 esophageal squamous cell carcinoma: a retrospective analysis of 295 patients.

OBJECTIVES: T1 esophageal squamous cell carcinoma (ESCC) has a low, but still present, risk of lymph node (LN) metastasis. Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is often applied for T1 ESCC. To achieve successful treatment by EMR/ESD, the risk of LN metastases, LN recurrence, and hematological recurrence need to be better understood. The aim of this study was to determine the precise risk for metastasis in T1 ESCC. METHODS: We divided 295 patients with T1 ESCC who underwent surgery and/or ESD/EMR into 6 categories (m1, m2, m3, sm1, sm2, and sm3). Their risks of LN metastasis, LN recurrence, hematological recurrence, and the outcome were determined. RESULTS: The rates of LN metastasis and LN recurrence were 0% in m1 and m2, 9% in m3, 16% in sm1, 35% in sm2, and 62% in sm3 cases. The incidence of hematological recurrence was 0% in m1, m2, m3, and sm1 cases; 9% in sm2 cases; and 13% in sm3 cases. The overall risk of metastasis was 9% in m3, 16% in sm1, 38% in sm2, and 64% in sm3 patients. The 5-year disease-specific survival rates were 100% in m1, m2, and m3; 90.9% in sm1; 78.8% in sm2; and 68.6% in sm3 patients. Statistically, both lymphatic and venous invasion were selected as predictive markers for metastasis. In m3 patients, positivity for either of these had an odds ratio for metastasis of 7.333 (P = 0.093). CONCLUSIONS: Our study provides a precise assessment of the comprehensive risk of metastasis and feasible predictive markers for T1 ESCC.

Primary esophageal adenocarcinoma arising from heterotopic gastric mucosa: report of a case.

Adenocarcinoma arising from heterotopic gastric mucosa (HGM) is exceedingly rare. This report presents the case of a 57-year-old male who presented with the chief complaint of dysphagia. Endoscopy and computed tomography revealed a locally advanced tumor of the cervical esophagus and swollen mediastinal lymph nodes. He underwent chemoradiotherapy followed by esophagectomy with three-field lymph node dissection. The resected tumor was a circumferentially scarred lesion located 1.5 cm from the proximal margin. The tumor was identified to be a well-differentiated adenocarcinoma arising from HGM with invasion to the muscularis propria. Postoperative chemoradiotherapy was performed because positive surgical margins were observed in the resected tissue. The patient has remained alive for more than 4 years after surgery, without any evidence of recurrence.

Preoperative evaluation of vascular anatomy of right colic vessels using enhanced computed tomographic colonography.

PURPOSE: The purpose of this study is to define the blood vessels from a surgical perspective and show the frequency of vascular anatomical anomalies as well as the positional relationship with the surrounding organs, including the number of jejunal veins that cross the dissection area in our series. MATERIALS AND METHODS: From January 2016 to December 2018, 126 patients who received ileocecal resection or right hemicolectomy for colonic cancer in our institution were retrospectively analyzed by preoperative enhanced computed tomographic colonography images that were obtained using an 80-detector row CT scanner and workstation. The ileocolic artery/vein, right colic artery/vein and middle colic artery/vein were defined as the vessels that flow directly from or into the superior mesenteric artery/vein. All colic veins that flowed into the gastro-colic trunk were defined as accessory right colic veins. RESULTS: The accessory right colonic vein existed more than two in 62.6% of cases. In 11 cases (8.9%), the inflow point of the ileocecal vein was on the ventral side of the pancreas. There was one jejunal vein that straddled the dissection area in 31% and two in 6.3%. CONCLUSION: This study elucidated the vascular anatomy and positional relationship with surrounding organs that is required in central vascular ligation during complete mesocolic excision for right sided colon cancer.

Lowering the setting value of the esophageal endoscopic submucosal dissection device enabled tissue damage control in vitro porcine model.

One of the complications of esophageal endoscopic submucosal dissection (ESD) is postoperative stricture formation. Stenosis formation is associated with inflammation and fibrosis in the healing process. We hypothesized that the degree of thermal damage caused by the device is related to stricture formation. We aimed to reveal the relationship between thermal damage and setting value of the device. We energized a resected porcine esophagus using the ESD device (Flush Knife 1.5). We performed 10 energization points for 1 s, 3 s, and 5 s at four setting values of the device. We measured the amount of current flowing to the conducted points and the temperature and evaluated the effects of thermal damage pathologically. As results, the mean highest temperatures for 1 s were I (SWIFT Effect3 Wat20): 61.19 °C, II (SWIFT Effect3 Wat30): 77.28 °C, III (SWIFT Effect4 Wat20): 94.50 °C, and IV (SWIFT Effect4 Wat30): 94.29 °C. The mean heat denaturation areas were I: 0.84 mm2, II: 1.00 mm2, III: 1.91 mm2, and IV: 1.54 mm2. The mean highest temperature and mean heat denaturation area were significantly correlated (P < 0.001). In conclusion, Low-current ESD can suppress the actual temperature and thermal damage in the ESD wound.

A double-scope technique enabled a patient with an esophageal plastic fork foreign body to avoid surgery: a case report and review of the literature.

Foreign body ingestion is a common problem, and endoscopic removal is often performed with ancillary equipment. However, long, sharp foreign bodies are much more difficult to remove endoscopically than other objects and require emergent surgery. A 68-year-old man with a history of distal gastrectomy accidentally swallowed a plastic fork. He complained of chest pain at the visit. The plastic fork was located between the thoracic esophagus and remnant stomach. Endoscopic removal of the plastic fork was considered difficult, and surgery was deemed necessary. However, we were able to avoid surgery to remove the object using two endoscopes with hoods and a polypectomy snare. The first endoscope covered the sharp edge with a hood, and the snare grasped the neck of the plastic fork. The second endoscope covered the remaining sharp tip. A single operator held the two endoscopes and the snare and pulled them out together. This new double-scope technique is simple and useful for removing long, sharp foreign bodies, such as forks, from the esophagus.

Why is endosonography insufficient for residual diagnosis after neoadjuvant therapy for esophageal cancer? Solutions using muscle layer evaluation.

BACKGROUND: The diagnosis of residual tumors using endoscopic ultrasound (EUS) after neoadjuvant therapy for esophageal cancer is considered challenging. However, the reasons for this difficulty are not well understood. AIM: To investigate the ultrasound imaging features of residual tumors and identify the limitations and potential of EUS. METHODS: This exploratory prospective observational study enrolled 23 esophageal squamous cell carcinoma patients receiving esophagectomy after neoadjuvant therapy [15 patients after neoadjuvant chemotherapy (NAC) and 8 patients after chemoradiotherapy (CRT)] at the Department of Surgery, Chiba University Hospital, between May 2020 and October 2021. We diagnosed the T stage for specimens using ultrasound just after surgery and compared ultrasound images with the cut surface of the fixed specimens of the same level of residual tumor. The ratio of esophageal muscle layer defect measured by ultrasound was compared with clinicopathological factors. Furthermore, the rate of reduction for the muscle layer defect was evaluated using EUS images obtained before and after neoadjuvant therapy. RESULTS: The accuracy of T stage rate was 61% (n = 14/23), which worsened after CRT (38%, n = 3/8) than after NAC (73%, n = 11/15) because of overstaging. Moreover, pT0 could not be diagnosed in all cases. The detection rate of residual tumor for specimens using ultrasound retrospectively was 75% (n = 15/20). There was no correlation between after-NAC (79%, n = 11/14) and after-CRT (67%, n = 4/6) detection rate. The detection of superficial and submucosal types was poor. The pathologic tumor size and pathological response were correlated. Tumor borders were irregular and echogenicity was mixed type after CRT. There was a correlation between the pT stage (pT0/1 vs pT2/3) and the length of muscle layer circumference (P = 0.025), the length of muscle layer defect (P < 0.001), and the ratio of muscle layer defect (P < 0.001). There was also a correlation between the pT stage and the rate of muscle layer defect reduction measured by EUS (P = 0.001). CONCLUSION: Compared to pathological images, some tumors are undetectable by ultrasound. Focusing on the esophageal muscle layer might help diagnose the depth of the residual tumor.