Rumi Shin

Depth of mesorectal extension has prognostic significance in patients with T3 rectal cancer.

BACKGROUND: More than half of all rectal cancers are T3 lesions, but they are classified as a single-stage category. OBJECTIVE: The aim of this study was to validate prognostic significance of mesorectal extension depth in T3 rectal cancer. DESIGN: This study is a retrospective analysis of oncologic outcomes of patients with T3 rectal cancer grouped by mesorectal extension depth (T3a, <1 mm; T3b, 1–5 mm; T3c, 5–15 mm; T3d, >15 mm). SETTINGS: This study was conducted at a tertiary referral cancer hospital. PATIENTS: From 2003 to 2009, 291 patients who underwent a curative surgery were included. MAIN OUTCOME MEASURES: Oncologic outcomes in terms of disease-free survival were analyzed. RESULTS: The 5-year disease-free survival rate according to T3 subclassification was 86.5% for T3a, 74.2% for T3b, 58.3% for T3c, and 29.0% for T3d. It was significantly higher in T3a,b tumors than that in T3c,d tumors (77.6% vs 55.2%, p < 0.001). On univariate and multivariate analysis, prognostic factors affecting recurrence were preoperative CEA level ≥5ng/mL (HR 2.617, 95% CI 1.620–4.226), lymph node metastasis (HR 3.347, 95% CI 1.834–6.566), and mesorectal extension depth >5 mm (HR 1.661, 95% CI 1.013–2.725). In subgroup analysis, independent prognostic factors were preoperative CEA level and mesorectal extension depth >5 mm for 200 patients with ypT3 rectal cancer and preoperative CEA level and lymph node metastasis for 91 patients with pT3 rectal cancer. LIMITATIONS: This study lacks quality of surgery plane evaluation because of its retrospective nature. Moreover, pathologic examination was not done with a whole-mount section. CONCLUSIONS: Depth of mesorectal extension >5 mm is a significant prognostic factor in patients with T3 rectal cancer. Depth of mesorectal extension especially may be more important than the nodal status in predicting the oncologic outcome for patients who had received preoperative chemoradiotherapy.

Management of Appendicitis Presenting with Abscess or Mass

Purpose Management strategy in acute appendicitis patients initially presenting with abscess or mass is surrounded with controversy. This study was performed to identify the outcomes of management for this condition. Methods We retrospectively analyzed prospectively registered 76 patients (male:female = 39:37; mean age, 50.8 years) with appendicitis presenting with abscess or mass over a 9-year period at the Seoul National University Hospital. Patients were divided into three groups (emergency operation group, delayed operation group, and follow-up group), and clinical characteristics and outcomes of treatment were investigated. Results Twenty-eight patients (36.8%) underwent an emergency operation. Of the remaining 48 patients, 20 (41.7%) were initially treated with conservative management through the use of antibiotics only; the other 28 (58.3%) with and additional ultrasound-guided percutaneous drainage of the abscess. Twenty-six (54.2%) patients underwent planned operations after conservative management, and 22 (45.8%) were followed without surgery (median duration, 37.8 month), of which 3 (13%) underwent an appendectomy due to recurrent appendicitis (mean of 56.7 days after initial attack). There were no statistical differences in types of operation performed (appendectomy or ileocecectomy), postoperative complications, and postoperative hospital stay among the patients who underwent emergency operations, delayed operations and operations for recurrence during follow-up. Conclusion Although the recurrence rate was relatively low after conservative management for appendicitis patients presenting with abscess or mass, there was no difference in surgical outcome between the emergent, elective, or recurrent groups. Our results indicate that proper management of appendicitis with abscess or mass can be selected according to surgeons preference.

Early outcome of the Korean Diagnosis-Related Groups payment system for appendectomy

Purpose The implementation of the Korean diagnosis-related groups (DRG) payment system has been recently introduced in selected several diseases including appendectomy in Korea. Here, we report the early outcomes with regard to clinical aspects and medical costs of the Korean DRG system for appendectomies in Seoul Metropolitan Government - Seoul National University Boramae Medical Center throughout comparing before and after introduction of DRG system. Methods The DRG system was applied since January 2013 at our institute. After the DRG system, we strategically designed and applied our algorithm for the treatment of probable appendicitis. We reviewed the patients who were treated with a procedure of appendectomy for probable appendicitis between July 2012 and June 2013, divided two groups based on before and after the application of DRG system, and compared clinical outcomes and medical costs. Results Total 416 patients were included (204 patients vs. 212 patients in the group before vs. after DRG). Shorter hospital stays (2.98 ± 1.77 days vs. 3.82 ± 1.84 days, P < 0.001) were found in the group after DRG. Otherwise, there were no significant differences in the perioperative outcomes and medical costs including costs for first hospitalization and operation, costs for follow-up after discharge, frequency of visits of out-patients clinic or Emergency Department or rehospitalization. Conclusion In the Korean DRG system for appendectomy, there were no significant differences in perioperative outcomes and medical costs, except shorter hospital stay. Further studies should be continued to evaluate the current Korean DRG system for appendectomy and further modifications and supplementations are needed in the future.

Does T3 Subdivision Correlate with Nodal or Distant Metastasis in Colorectal Cancer

Purpose We analyzed the clinical data of T3 colorectal cancer patients to assess whether T3 subdivision correlates with node (N) or metastasis (M) staging and stage-independent factors. Methods Five hundred fifty-five patients who underwent surgery for primary colorectal cancer from January 2003 to December 2009 were analyzed for T3 subdivision. T3 subdivision was determined by the depth of invasion beyond the outer border of the proper muscle (T3a, <1 mm; T3b, 1 to 5 mm; T3c, >5 to 15 mm; T3d, >15 mm). We investigated the correlation between T3 subdivision and N, M staging and stage-independent prognostic factors including angiolymphatic invasion (ALI), venous invasion (VI) and perineural invasion (PNI). Results The tumors of the 555 patients were subclassified as T3a in 86 patients (15.5%), T3b in 209 patients (37.7%), T3c in 210 patients (37.8%) and T3d in 50 patients (9.0%). The nodal metastasis rates were 39.5% for T3a, 56.5% for T3b, 75.7% for T3c and 74.0% for T3d. The distant metastasis rates were 7.0% for T3a 9.1% for T3b, 27.1% for T3c and 40.0% for T3d. Both N and M staging correlated with T3 subdivision (Spearmans rho = 0.288, 0.276, respectively; P < 0.001). Other stage-independent prognostic factors correlated well with T3 subdivision (Spearmans rho = 0.250, P < 0.001 for ALI; rho = 0.146, P < 0.001 for VI; rho = 0.271, P < 0.001 for PNI). Conclusion Subdivision of T3 colorectal cancer correlates with nodal and metastasis staging. Moreover, it correlates with other prognostic factors for colorectal cancer.

Clinical Features of Colorectal Cancer Detected by the National Cancer Screening Program

Purpose Since 2004, the National Cancer Screening Program of Korea has included colorectal cancer screening based on primary screening with the fecal occult blood test (FOBT). We report on the clinical features of colorectal cancer detected by the National Cancer Screening Program. Methods We retrospectively analyzed 577 patients who underwent elective surgery for colorectal cancer at the Seoul National University Hospital between January 2008 and December 2009. We compared the clinical features of colorectal cancers detected by the National Cancer Screening Program (NCSP group) with those of the control group in terms of age, gender, preoperative symptom, location of the tumor, surgical technique and tumor-node-metastasis (TNM) stage. Results Age, gender, location of the tumor and operation types were not different between the two groups. The proportion of asymptomatic patients was significantly higher in the NCSP group than it was in the control group (86.5% vs. 20.0%; P < 0.001). The proportion of less invasive lesions (T1 or T2) was significantly higher in the NCSP group (46.3% vs. 27.7%; P = 0.002). The pathologic stages of the colorectal cancers in the NCSP group were I, 40.3%; II, 17.9%; III, 40.3% and IV, 1.5% whereas in the control group, they were I, 20.8%; II, 32.9%; III, 34.9% and IV, 11.4%. The proportion of stage I cancer was significantly higher in the NCSP group than in the control group (40.3% vs. 20.8%; P = 0.006). Conclusion Our study demonstrates the FOBT in the NCSP is effective in early detection of colorectal cancer.

Jejuno-jejunal fistula induced by magnetic necklace ingestion

We describe the case of a 19-year-old mentally challenged woman who developed jejuno-jejunal fistula following ingestion of a magnetic necklace. This case report demonstrates the necessity of prompt treatment when the ingested intestinal foreign body is suspected to be multiple magnets, even if there are no sharp edges; and even when it seems the object could be evacuated spontaneously. Ingested magnets are capable of attracting each other across the bowel wall, leading to serious intestinal complications such as pressure necrosis, perforation, fistula formation, or intestinal obstruction.

Unexpected Appendiceal Pathologies and Their Changes With the Expanding Use of Preoperative Imaging Studies

Purpose The preoperative diagnosis of acute appendicitis is often challenging. Sometimes, pathologic results of the appendix embarrass or confuse surgeons. Therefore, more and more imaging studies are being performed to increase the accuracy of appendicitis diagnoses preoperatively. However, data on the effect of this increase in preoperative imaging studies on diagnostic accuracy are limited. We performed this study to explore unexpected appendiceal pathologies and to delineate the role of preoperative imaging studies in the diagnosis of acute appendicitis. Methods The medical records of 4,673 patients who underwent an appendectomy for assumed appendicitis between 1997 and 2012 were reviewed retrospectively. Pathological results and preoperative imaging studies were surveyed, and the frequencies of pathological results and preoperative imaging studies were investigated. Results The overall rate of pathology compatible with acute appendicitis was 84.4%. Unexpected pathological findings, such as normal histology, specific inflammations other than acute appendicitis, neoplastic lesions, and other pathologies, comprised 9.6%, 3.3%, 1.2%, and 1.5%, respectively. The rate of unexpected pathological results was significantly reduced because of the increase in preoperative imaging studies. The decrease in normal appendices contributed the most to the reduction while other unexpected pathologies did not change significantly despite the increased use of imaging studies. This decrease in normal appendices was significant in both male and female patients under the age of 60 years, but the differences in females were more prominent. Conclusion Unexpected appendiceal pathologies comprised 15.6% of the cases. Preoperative imaging studies reduced them by decreasing the negative appendectomy rate of patients with normal appendices.

Predictors of Morbidity and Mortality After Surgery for Intestinal Perforation

Purpose An intestinal perforation is a rare condition, but has a high mortality rate, even after immediate surgical intervention. The clinical predictors of postoperative morbidity and mortality are still not well established, so this study attempted to identify risk factors for postoperative morbidity and mortality after surgery for an intestinal perforation. Methods We retrospectively analyzed the cases of 117 patients who underwent surgery for an intestinal perforation at a single institution in Korea from November 2008 to June 2014. Factors related with postoperative mortality at 1 month and other postoperative complications were investigated. Results The mean age of enrolled patients was 66.0 ± 15.8 years and 66% of the patients were male. Fifteen patients (13%) died within 1 month after surgical treatment. Univariate analysis indicated that patient-related factors associated with mortality were low systolic and diastolic blood pressure, low serum albumin, low serum protein, low total cholesterol, and high blood urea nitrogen; the surgery-related factor associated with mortality was feculent ascites. Multivariate analysis using a logistic regression indicated that low systolic blood pressure and feculent ascites independently increased the risk for mortality; postoperative complications were more likely in both females and those with low estimated glomerular filtration rates and elevated serum C-reactive protein levels. Conclusion Various factors were associated with postoperative clinical outcomes of patients with an intestinal perforation. Morbidity and mortality following an intestinal perforation were greater in patients with unstable initial vital signs, poor nutritional status, and feculent ascites.

Rectal Perforation Caused by Anal Stricture After Hemorrhoid Treatment

Inappropriate therapies for hemorrhoids can lead to various complications including anorectal stricture. We report a patient presenting with catastrophic rectal perforation due to severe anal stricture after inappropriate hemorrhoid treatment. A 67-years old man with perianal pain visited the emergency room. The hemorrhoids accompanied by constipation, had tortured him since his youth. Thus he had undergone injection sclerotherapy several times by an unlicensed therapist and hemorrhoidectomy twice at the clinics of private practitioners. His body temperature was as high as 38.5℃. The computed tomographic scan showed a focal perforation of posterior rectal wall. The emergency operation was performed. The fibrotic tissues of the anal canal were excised. And then a sigmoid loop colostomy was constructed. The patient was discharged four days following the operation. This report calls attention to the enormous risk of unlicensed injection sclerotherapy and overzealous hemorrhoidectomy resulting in scarring, progressive stricture, and eventual rectal perforation.

Abstract B140: Autologous human growing tumor model and its immunological relevance for cancer immunology research

Background: Tumors grow in accordance with immunoediting. If we can see the changes of immune characteristics in the microenvironment during tumor growth, we can have much information of the mechanism of immunoediting. Peritoneal tumor cells from colorectal cancers are mostly derived from the shedding of tumor cells exposed on the visceral peritoneum. After the surgical removal of the primary tumors of which cells are exposed on the visceral peritoneum (T4 stage) but without macroscopic tumor seedings in the peritoneal cavity, some patients experience peritoneal recurrence but others do not. This implies that in the patients with future peritoneal recurrences the microscopic tumor cells in the peritoneal cavity have already been immunoedited. In addition, ascites and peritoneal immune cells are components of tumor microenvironment during peritoneal tumor growth if the peritoneal cavity is not contaminated by microorganisms by bowel perforation. And ascites and peritoneal cells are appropriate materials for immediate analysis after collection. Therefore, if we establish peritoneal immune characteristics of each T4 patient and compare those between the recurred and non-recurred patients in the peritoneal cavity afterwards, we can hold the clues of immunoediting during the peritoneal tumor growth. In this study we tested this autologous human growing tumor model for the relevance of research subject for cancer-associated immune response, as a pilot study. Method: Ascites and peritoneal cells were collected during the operation of colon cancer patients. If blood were mixed during the collection, the ascites and cells were discarded. The patients, whose ascites and peritoneal cells had been harvested, were classified into four groups (PC stages) according to the progression of peritoneal tumor growth on the basis of pathological report. SE-(serosa exposure negative; no tumor cells in peritoneal cavity) is a group of patients without exposure of cancer cells to peritoneal cavity (T3 or lower T stage). SE+(serosa exposure positive; microscopic tumor cells in peritoneal cavity) is a group of patients of T4 lesion without peritoneal seedings. l-PC represents localized peritoneal seedings which could be removed entirely during surgery. g-PC is a group of generalized peritoneal seeding. We performed ELISA and flow cytometry analysis as well as immune cell activation. Result: Of the 10 cytokines assayed in ascites, IL10, IL6 and TGF-beta increased according to the tumor progression in the peritoneal cavity, while the other cytokines (IL2, IL4, IL5, IL12, IL17, TNF and IFN-gamma) did not show any changes. Of the 42 SE+ patients, eleven experienced peritoneal recurrences. Mean IL10 (42 vs 24 pg/mL) and IL6 (2,092 vs 4472 pg/mL) levels of patients with peritoneal recurrence were higher than those without recurrence although we could not have significance (P = 0.113 and 0.180 each, Mann-Whitney U test). Activation of peritoneal cells by LPS increased IL6 as well as IL10 while activation by antiCD3 and antiCD28 did not. Intracellular IL10 was stained in T cells while IL6 in CD14 cells after LPS stimulation. Moreover, although ascitic IL6 increased up to tens of thousands pg/mL in g-PC patients, the blood level stayed at tens pg/mL. This means the ascites and peritoneal immune cells belong to a microenvironment which is seldom reflected in peripheral blood. Conclusion: This model showed the possibility of relevance to explore cancer-associated immune response in the tumor microenvironment during tumor growth in colorectal cancer. It is expected that further studies will provide much information of the mechanism of suppression of anti-tumor immune response. And the results derived from this model can help to extend understandings of immunoediting in primary tumors, metastatic tumors and, further, in other cancers. Citation Format: Seung Chul Heo, Sang Mok Lee, Beonghoon Sohn, Ji-Eun Kim, Rumi Shin. Autologous human growing tumor model and its immunological relevance for cancer immunology research [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B140.