Single-incision laparoscopic surgery for benign multicystic mesothelioma of the peritoneum in a young man: A case report.

Benign multicystic peritoneal mesothelioma (BMPM) is a rare condition, particularly in men, and the preoperative diagnosis poses a challenge. Here, we present a case involving single-incision laparoscopic surgery (SILS) for BMPM in a 24-year-old man with a pelvic mass and a history of ulcerative colitis. Pelvic imaging revealed multifocal cysts, prompting the performance of SILS. The tumor was successfully resected with no residual lesions, and pathology confirmed the diagnosis of BMPM. This case represents the first documented instance of SILS being employed for BMPM in a man. BMPM, characterized by pelvic multifocal cysts, is a differential diagnosis, and SILS emerges as a viable option for both diagnosis and treatment.

Usefulness of real-time navigation using intraoperative ultrasonography for rectal cancer resection.

INTRODUCTION: At our institute, we usually perform robot-assisted surgery for rectal cancer as minimally invasive surgery. It is necessary to recognize the tumor edge accurately when deciding where to place the distal cutting line of the rectum. In this article, with video presentation, we demonstrate the usefulness of intraoperative sonography (IOUS) for detecting the rectal tumor site in robotic surgery. This is the first report to discuss the IOUS image of rectal cancer. MATERIALS AND SURGICAL TECHNIQUE: After mobilization of the rectum in robotic procedure, the rectum should be straightened. Drop the laparoscopic ultrasonography probe through the 12-mm assistant port and place it at the anterior wall of the rectum. By presenting operative and ultrasound findings simultaneously on a single monitor, the operator can recognize the tumor location accurately and decide on the cutting line. We report three cases in the supporting video presentation. DISCUSSION: Rectal tumors can be detected by IOUS, and this modality is effective for determining the cutting line of the rectum. Real-time navigation by IOUS can be performed noninvasively and easily, so it is expected to be helpful in cases of robotic rectal cancer resection.

Prognostic value of 18F-FDG PET/CT with texture analysis in patients with rectal cancer treated by surgery.

PURPOSE: The aim of this study was to evaluate the ability of texture analysis using pretreatment 18F-FDG PET/CT to predict prognosis in patients with surgically treated rectal cancer. METHODS: We analyzed 94 patients with pathologically proven rectal cancer who underwent pretreatment 18F-FDG PET/CT and were subsequently treated with surgery. The volume of interest of the primary tumor was defined using a threshold of 40% of the maximum standardized uptake value (SUVmax), and conventional (SUVmax, metabolic tumor volume [MTV], total lesion glycolysis [TLG]) and textural PET features were extracted. Harmonization of PET features was performed with the ComBat method. The study endpoints were overall survival (OS) and progression-free survival (PFS), and the prognostic value of PET features was evaluated by Cox regression analysis. RESULTS: In the follow-up period (median 41.7 [interquartile range, 30.5-60.4] months), 21 (22.3%) and 30 (31.9%) patients had cancer-related death or disease progression, respectively. Univariate analysis revealed a significant association of (1) MTV, TLG, and gray-level co-occurrence matrix (GLCM) entropy with OS; and (2) SUVmax, MTV, TLG, and GLCM entropy with PFS. In multivariate analysis including clinical characteristics, GLCM entropy (≥ 2.13) was the only relevant prognostic PET feature for poor OS (hazard ratio [HR]: 4.16, p = 0.035) and PFS (HR: 2.70, p = 0.046). CONCLUSION: GLCM entropy, which indicates metabolic intratumoral heterogeneity, was an independent prognostic factor in patients with surgically treated rectal cancer. Compared with conventional PET features, GLCM entropy has better predictive value and shows potential to facilitate precision medicine.

Definition and characterization of the descending branch of the left colic artery.

PURPOSE: The descending branch of the left colic artery (dLCA) is under-recognized and has not been clearly defined. The dLCA is often confused with the sigmoid artery (SA) originating from the left colic artery (LCA). We clarified the anatomical characteristics of the dLCA and searched for surrogate measures to identify it. METHODS: Arterial phase, venous phase, and three-dimensional images of abdominal arteries were created in 411 patients using contrast-enhanced computed tomography (CT). We analyzed the branching patterns of the inferior mesenteric artery (IMA) based on CT. The dLCA was defined as the artery originating from the LCA that flows into the marginal artery along the descending colon. We tested three candidate diagnostic measures for the dLCA using positional relationships and the segment length of vessels. RESULTS: Arteries from the LCA were present in 360 patients, among which 459 dLCAs and 165 SAs were identified in 333 and 146, respectively. By the first measure of identifying the artery with its root lateral to the inferior mesenteric vein (IMV) as the dLCA, the sensitivity, specificity, and accuracy rate were 94%, 87%, and 92%, respectively. The second measure of identifying the artery with its root higher than the root of the IMA as the dLCA and the third of identifying the artery with its root located > 27.6 mm from the root of LCA as the dLCA yielded lower accuracy rates (69% and 89%, respectively). CONCLUSION: Our study demonstrated that dLCAs are prevalent (93%) and may be easily found lateral to the IMV in clinical practice.

The primary tumor location in colorectal cancer: A focused review on its impact on surgical management.

The primary tumor location (PTL) has attracted increasing attention in recent years for colorectal cancer (CRC) patients. Although the underlying mechanisms for differences caused by PTL remain still unclear, right-sided colon (RCC) and left-sided colon (LCC) are now considered as distinct entities because of their different molecular profile and clinical response to surgery and chemotherapy. In this article, we review the influence of PTL particularly on surgical management of primary and metastatic CRC settings. For nonmetastatic CRC, RCC could be a slightly superior prognostic factor after curative resection in stage I-II CRC, while RCC could be an inferior prognostic factor in stage III CRC with worse survival after recurrence, suggesting the oncological aggressiveness of recurrent RCC. For metastatic CRC, RCC could be a predictor of worse survival after hepatectomy of liver metastases from CRC with aggressive recurrence pattern and lower chance of re-resection. In lung metastases from CRC, the role of PTL still remains uncertain because of the limited number of studies. As to the impact of PTL on survival outcome after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for peritoneal metastases from CRC, a discrepancy exists among studies and further investigation will be needed. The very simple clinical factor of PTL could provide important information for the prediction of the survival outcome after surgery in CRC. Further clinical and basic research will facilitate the clinical application of PTL in a more specified and personalized manner.

Efficacy of intraperitoneally administered paclitaxel for colorectal cancer with peritoneal metastases.

PURPOSE: Prognosis after peritoneal metastases in colorectal cancer is worse than that after lung or liver metastases. Previously, we demonstrated the safety of intraperitoneal (ip) administration of paclitaxel (PTX) combined with mFOLFOX6/CapeOX plus bevacizumab for colorectal cancer with peritoneal metastasis in a phase-I trial. Here, we evaluated the efficacy of this chemotherapy. METHODS: We enrolled six patients with histologically confirmed peritoneal metastases secondary to colorectal cancer. PTX was administered through a peritoneal access port, in combination with oxaliplatin-based systematic chemotherapy. Response rate, progression-free survival, 1-year survival rate, frequency of improvement in peritoneal cancer index (PCI), and cytology in peritoneal lavage were evaluated. This study was registered in the University Hospital Medical Information Network Clinical Trial Registry on July 1, 2016 (UNIN000022924). RESULTS: Three patients received the mFOLFOX6-bevacizumab regimen, whereas the other three received the CapeOX-bevacizumab regimen. The response rate was 25%. PCI score improved in 50% of the cases. Peritoneal lavage cytology that was positive in five patients before initiating the chemotherapy turned negative during chemotherapy in all patients. One-year survival rate was 100%, progression-free survival was 8.8 months (range, 6.8-12 months), and median survival time was 29.3 months. CONCLUSION: The ip administration of PTX with systemic chemotherapy can potentially control peritoneal metastases in colorectal cancer.

The combination of temsirolimus and chloroquine increases radiosensitivity in colorectal cancer cells.

The PI3K/AKT/mTOR pathway and autophagy are known to play important roles in cancer radioresistance. The aim of the present study was to investigate whether the combination of temsirolimus (TEM), an mTOR inhibitor, and chloroquine (CQ), an autophagy inhibitor, can increase radiosensitivity in colorectal cancer (CRC) cells. The efficacies of TEM and/or CQ as radiosensitizers were examined using clonogenic assays in CRC cell lines SW480 and HT­29. The expression levels of the phosphorylated isoforms of S6 and 4E­BP1, downstream proteins of mTOR, as well as the expression levels of p62 and LC3, autophagy­related proteins, were assessed by western blot analysis. The formation of acidic organelles was detected in acridine orange­stained cells. Apoptosis and caspase activity were assessed using flow cytometry. The results revealed that ionizing radiation (IR) activated the downstream proteins of mTOR and induced autophagy. In the clonogenic assays, neither TEM nor CQ influenced the efficacy of IR, whereas their combination significantly increased the dose­dependent efficacy of IR. TEM inhibited phosphorylation of the downstream proteins of mTOR and induced autophagy. CQ inhibited autophagy in the late phase and did not influence the downstream proteins of mTOR. TEM and CQ inhibited both the phosphorylation of downstream proteins of mTOR and autophagy. Cell death analysis revealed that the combination of TEM and CQ strongly induced apoptosis in cells exposed to IR. In conclusion, the combination of TEM and CQ increased radiosensitivity in CRC cells through co­inhibition of mTOR and autophagy.

The influence of neoadjuvant chemoradiation for lower rectal cancer on urinary function.

BACKGROUND: It is unclear whether neoadjuvant chemoradiation for lower rectal cancer causes a deterioration in urinary function. This study aimed to prospectively compare the postoperative urinary function of patients with lower rectal cancer treated by surgery after neoadjuvant chemoradiation with that of patients treated with surgery alone. METHOD: Urinary function was assessed before treatment and 1, 3, and 6 months after surgery by calculating the changes in the scores of the seven items of the International Prostatic Symptom Score (incomplete emptying, frequency, intermittency, urgency, weak stream, straining, and nocturia) and Quality of life index. RESULTS: Among 123 patients with lower rectal cancer treated with chemoradiotherapy plus surgery and surgery alone between 2014 and 2016, 29 eligible patients in the surgery after neoadjuvant chemoradiation group and 34 eligible patients in the surgery alone group were analyzed. The changes in each item score at 1, 3, and 6 months after surgery were similar between the two treatment groups. The scores of all items were already recovered at 6 months after surgery, except for weak stream and straining in the Surgery + chemoradiotherapy group and nocturia in the Surgery-alone group. CONCLUSION: Neoadjuvant chemoradiotherapy for lower rectal cancer did not affect postoperative urinary function.

Safety of intraperitoneal paclitaxel combined with conventional chemotherapy for colorectal cancer with peritoneal carcinomatosis: a phase I trial.

PURPOSE: Peritoneal carcinomatosis of colorectal cancer origin is associated with poor prognosis. With regard to ovarian, gastric, and pancreatic cancer, the safety and efficacy of intraperitoneal administration of paclitaxel (ip PTX) has been demonstrated. This drug can be administered easily and repeatedly through a catheter into the peritoneal cavity. In this phase I study, we evaluated the safety of ip PTX combined with 5-fluorouracil, folinic acid, oxaliplatin, and bevacizumab (mFOLFOX6-bevacizumab) or capecitabine, oxaliplatin, and bevacizumab (CapeOX-bevacizumab) for colorectal cancer with peritoneal metastasis. METHODS: Colorectal cancer patients with histologically confirmed peritoneal carcinomatosis were enrolled. After the implantation of a peritoneal access port, 20 mg/m2 of ip PTX was administered weekly, in combination with mFOLFOX6-bevacizumab or CapeOX-bevacizumab. Primary endpoint was the safety of the combination chemotherapy. RESULTS: Among the six patients enrolled, three received the mFOLFOX6-bevacizumab plus ip PTX regimen and three received the CapeOX-bevacizumab plus ip PTX regimen. Dose-limiting toxicity was not observed. Overall, grade 3 adverse events, such as leukopenia and neutropenia, were observed in two of three patients (66.7%) for each chemotherapeutic regimen, but no grade 4 adverse events were observed. Moreover, adverse events associated with the peritoneal access port, such as infection or occlusion of the catheter, were not observed. CONCLUSIONS: The adverse events of mFOLFOX6-bevacizumab or CapeOX-bevacizumab in combination with ip PTX were considered similar to those described in previous studies of oxaliplatin-based treatment alone. 1 year after the start of chemotherapy, the efficacy of ip PTX will be evaluated as a secondary outcome.

Colon cancer with perforation.

Perforation of the colon is a rare complication for patients with colon cancer and usually requires emergent surgery. The characteristics of perforation differ based on the site of perforation, presenting as either perforation at the cancer site or perforation proximal to the cancer site. Peritonitis due to perforation tends to be more severe in cases of perforation proximal to the cancer site; however, the difference in the outcome between the two types remains unclear. Surgical treatment of colon cancer with perforation has changed over time. Recently, many reports have shown the safety and effectiveness of single-stage operation consisting of resection and primary anastomosis with intraoperative colonic lavage. Under certain conditions, laparoscopic surgery can be feasible and help minimize the invasion. However, emergent surgery for colon cancer with perforation is associated with a high rate of mortality and morbidity. The long-term prognosis seems to have no association with the existence of perforation. Oncologically curative resection may be warranted for perforated colon cancer. In this report, we perform a literature review and investigate the characteristics and surgical strategy for colon cancer with perforation.

Short- and Long-term Outcomes of Minimally Invasive Versus Open Multivisceral Resection for Locally Advanced Colorectal Cancer.

BACKGROUND: Colorectal cancer invading the adjacent organs/structures is detected in 5% to 20% of all surgical interventions performed for the management of colorectal cancer. OBJECTIVE: Our purpose is to verify the safety and feasibility of laparoscopic surgery for the treatment of locally advanced colorectal cancer invading the adjacent organs. DESIGN: This is a retrospective study. SETTINGS: The study was conducted at a single institution in Japan. PATIENTS: We compared the morbidity, appropriate oncological resection, and disease-free survival of laparoscopic and open multivisceral resection in patients with colorectal carcinoma in the period between 2007 and 2015. MAIN OUTCOME MEASURES: The primary outcome measures were curative resection rate, morbidity rate, and recurrence of laparoscopic and open multivisceral resection in patients with colorectal cancer. RESULTS: Thirty-one patients received laparoscopic surgery, and 50 received open surgery. The amount of blood loss was smaller in the laparoscopic group than in the open group (60 vs 595 mL, p < 0.01). Curative surgery was performed in 46 patients of the open group (92.0%) and in 30 patients of the laparoscopic group (96.8%). Days until oral intake (5 vs 7 days, p < 0.01) and postoperative hospital stay (14 vs 19 days, p < 0.01) were shorter in the laparoscopic group. Overall morbidity was not different between the groups (22.5% vs 40.0%). Three-year disease-free survival rates were 62.7% in the open group and 56.7% in the laparoscopic group (p = 0.5776). LIMITATION: This study was a retrospective small study conducted at a single institute. CONCLUSION: Laparoscopic multivisceral resection may be a safe, less invasive alternative to open surgery, with less blood loss and shorter hospital stay, and was not inferior to open surgery based on long-term oncological end points. See Video Abstract at http://links.lww.com/DCR/A785.

Efficacy of 18-fluoro deoxy glucose-positron emission tomography computed tomography for the detection of colonic neoplasia proximal to obstructing colorectal cancer.

Identification of secondary colonic neoplasia proximal to obstructing colorectal cancer is essential for determining the range of colorectal resection.We examined the accuracy of 18-fluoro deoxy glucose-positron emission tomography (FDG-PET) for detection of colonic neoplasia.We recruited patients with obstructing colorectal cancer from our registry. Preoperative FDG-PET was performed, and the detection rate for colonic neoplasia was estimated. Preoperative colonoscopy or postoperative colonoscopy within a year after operation was employed as the indexed standard.Ninety-three patients were included in this study. Colonic neoplasia proximal to obstruction was confirmed in 83 cases. The sensitivity and positive predictive value of FDG-PET were 25.3% and 77.8%, respectively. The sensitivity was higher in larger lesions (3.2% for <5 mm, 29.4% for 6-10 mm, 45.5% for 11-20 mm, and 71.4% for >21 mm) and in higher pathological grade lesions (14.6% for low-grade adenoma, 38.5% for high-grade adenoma, 66.7% for carcinoma in situ, and 100% for invasive carcinoma). The round shape in PET images was a predictor for neoplasia, with an area under the curve of 0.75293 at an aspect ratio of 1.70.FDG-PET should be used as a screening modality for invasive colorectal cancer (CRC) proximal to obstructing colorectal cancer.

High-risk Stage II Colorectal Cancers Carry an Equivalent Risk of Peritoneal Recurrence to Stage III.

BACKGROUND/AIM: Several risk factors for recurrence have been identified in stage II colorectal cancer. However, in contrast to stage III, the benefits of adjuvant chemotherapy for these patients remain controversial. We hypothesized that the different impacts of chemotherapy may be due to different patterns of recurrence between these stages. The aim of this study was to characterize recurrence in high-risk stage II colorectal cancer (CRC) in comparison with stage III. PATIENTS AND METHODS: A total of 442 patients with curatively resected stage III and high-risk stage II CRCs were evaluated. The recurrence site and frequency were compared between these stages. The risk factors of recurrence by site were identified using multivariate analyses. RESULTS: During the follow-up (median: 6.4 years), 31% of stage III and 13% of high-risk stage II patients manifested recurrence. Recurrence in the liver, lung, and distant lymph nodes was significantly more frequent in stage III (18%, 12%, 11%) than in high-risk stage II (7%, 6%, 3%). Stage III was independently associated with recurrence in these organs. In contrast, the rate of peritoneal recurrence was 5% in both stages. CONCLUSION: Clinicians should be aware that high-risk stage II CRC has a similar risk of postoperative recurrence in the peritoneum to Stage III CRC.

Over-diagnosis for preoperative T staging of colorectal cancer - A case series.

INTRODUCTION: Recent progressive imaging technology such as multiplanar reconstruction on computed tomography (CT) and colonoscopy has made preoperative T staging of colorectal cancer (CRC) more accurate. Nevertheless, it is still difficult to make a correct diagnosis in some cases. The aim of this case study was to investigate the accuracy of T staging diagnosis in patients with CRC who underwent curative operations and to identify the causes of preoperative over-diagnosis. METHOD: Medical charts of 1013 colorectal cancer patients who underwent a curative operation in the University of Tokyo Hospital between January 2011 and December 2016 were analyzed retrospectively. We defined a two-level or more difference between clinical and pathological T stages as over-diagnosis or under-diagnosis. RESULTS: Nine patients were over-diagnosed in T stage preoperatively. The rate of over-diagnosis was 0.9%. At least three main factors for over-diagnosis were identified: close-to-circumferential or obstructive lesion; a rough appearance in the adipose tissues around the tumor on CT; and a tumor with a depressed structure. CONCLUSIONS: Clinical T stage is overestimated with a marked difference from pathological T stage in approximately 1% of CRC patients. Further progress in diagnostic modalities is required for more accurate staging.

Elevated risk of stoma outlet obstruction following colorectal surgery in patients undergoing ileal pouch-anal anastomosis: a retrospective cohort study.

PURPOSE: Stoma outlet obstruction (SOO) is a complication following colorectal surgery that requires stoma creation. We aimed to clarify the SOO incidence and identify risk factors for SOO after stoma surgery in patients with ulcerative colitis (UC) or rectal cancer. METHODS: The study included 345 patients with sporadic rectal cancer (n = 301) or UC (n = 44) who underwent stoma surgery between 2012 and 2017. Univariate and multivariate analyses were performed to identify risk factors for SOO. RESULTS: The SOO incidences were 27.3% (n = 12) in patients with UC and 5.6% (n = 17) in patients with sporadic rectal cancer. A multivariate analysis identified UC and loop ileostomy as independent risk factors for SOO. Subanalyses revealed that loop ileostomy was an independent risk factor for patients with UC or sporadic rectal cancer. Most patients who developed SOO were successfully managed with tube drainage through the stoma. However, stoma closure was performed earlier than originally planned in two patients. Among the 29 patients with SOO, 22 (75.9%) developed SOO within 2 weeks postoperatively; the median period between stoma creation and SOO was 6 (range 3-41) days. CONCLUSIONS: UC and loop ileostomy are independent risk factors for postoperative SOO.

Phase I/II Study of Preoperative Chemoradiotherapy With TEGAFIRI for Locally Advanced Rectal Cancer.

INTRODUCTION: Chemoradiotherapy (CRT) is the standard treatment for locally advanced rectal cancer; however, the optimal chemotherapy sequence to administer simultaneously with radiotherapy remains unclear. We conducted a phase I/II study to test a new regimen, TEGAFIRI (combination tegafur, uracil [UFT], leucovorin [LV], irinotecan), for patients with locally advanced rectal cancer. PATIENTS AND METHODS: A total of 22 patients with locally advanced lower rectal adenocarcinoma were enrolled in the present study. The radiation dose was 50.4 Gy in 28 fractions. UFT (300 mg/m2/d) and LV (75 mg/body weight/d) were administered orally 3 times daily. Irinotecan was administered as an intravenous infusion at 3 escalating dose levels. The initial dose was 50 mg/m2 (level 1; n = 7), the intermediate was 70 mg/m2 (level 2; n = 8), and the maximum was 80 mg/m2 (level 3; n = 7). The drug was administered on days 1, 15, 29, and 43. RESULTS: Dose-limiting toxicity was not observed at any dosing level. The most frequent adverse event was leukopenia (50%), followed by diarrhea (45.5%), anal pain (31.8%), and neutropenia (27.3%). All were well-managed with the appropriate drugs. The total pathologic complete response rate was 22.7%, and the proportion of good responders was 28.6%, 50%, and 71.4% at levels 1, 2, and 3, respectively. None of the patients experienced local recurrence. The 5-year relapse-free and overall survival rates were 80.4% and 80.8%, respectively. CONCLUSION: TEGAFIRI is a promising CRT regimen that results in marked tumor regression and good local control. Moreover, its adverse events are well-tolerated.

Comparison of the guidelines for colorectal cancer in Japan, the USA and Europe.

Colorectal cancer (CRC) is one of the most common cancers globally as well as in Japan and has shown a pattern of increasing incidence and mortality rates. Therefore, guidelines for CRC are considered to be crucial for establishing standard medical treatment not only in Japan but also around the world. In this article, we explain the features of the representative guidelines in Japan (Japanese Society for Cancer of the Colon and Rectum [JSCCR]), the USA (National Comprehensive Cancer Network [NCCN]) and Europe (European Society for Medical Oncology [ESMO]) and review the differences among these guidelines for CRC. We focus, in particular, on the descriptions of local treatments, including endoscopic treatment for CRC and transanal excision for lower rectal cancer; surgical treatments with lymph node dissection, including management of lower rectal cancer with lateral lymph node metastasis and laparoscopic surgery; and chemotherapy. Although the guidelines share basic principles, some details are different. Consulting the guidelines of various regions from around the world may aid in more precise and effective examination of the details and backgrounds of our own native guidelines.

Learning Curve of Robotic Rectal Surgery With Lateral Lymph Node Dissection: Cumulative Sum and Multiple Regression Analyses.

OBJECTIVE: This study aimed to assess the learning curve of robotic rectal surgery, a procedure that has gained increasing focus in recent years because it is expected that the advanced devices used in this approach provide advantages resulting in a shorter learning curve than that of laparoscopic surgery. However, no studies have assessed the learning curve of robotic rectal surgery, especially when lateral lymph node dissection is required. DESIGN: This was a nonrandomized, retrospective study from a single institution. SETTING: All consecutive patients who underwent robotic rectal or sigmoid colon surgery by a single surgeon between February 2012 and July 2016 in the University of Tokyo Hospital were enrolled. The learning curve for console time was assessed using a cumulative sum analysis and multiple linear regression analysis. PARTICIPANTS: A total of 131 consecutive patients underwent robotic rectal or sigmoid colon surgery performed by a single experienced surgeon. Of these, 41 patients received lateral lymph node dissection. RESULTS: A cumulative sum plot for console time demonstrated that the learning period could be divided into 3 phases: Phase I, Cases 1 to 19; Phase II, Cases 20 to 78; and Phase III, Cases 79 to 131. Multiple linear regression analysis indicated that console time decreased significantly from one phase to another (Phase I-II, Δconsole time 83.0 minutes; Phase II-III, Δconsole time 40.1 minutes). Other factors affecting console time included body mass index, operative procedure, and lateral lymph node dissection, but not neoadjuvant therapy (such as chemoradiotherapy) or depth of invasion. Lateral lymph node dissection required an additional 138.4 minutes. CONCLUSIONS: Our findings suggest that the first phase of the learning curve consists of the first 19 cases, which seems sufficient to master the manipulation of robotic arms and to understand spatial relationships unique to the robotic procedure.

Prognostic impact of doublecortin-like kinase 1 expression in locally advanced rectal cancer treated with preoperative chemoradiotherapy.

Preoperative chemoradiotherapy (CRT) is a standard therapy for locally advanced rectal cancer; however, the response varies depending on cases. Therefore, CRT-response predictors need to be elucidated. Cancer stem cells (CSCs), comprising a small part of tumors, are associated with tumor progression and recurrence due to their self-renewal and proliferation abilities. Doublecortin-like kinase 1 (DCLK1) is one of the several putative CSC markers; however, the clinical impact of its expression in rectal cancer has not been evaluated. The aim of this study was to clarify the clinical impact of DCLK1 expression in rectal cancer. We immunohistochemically evaluated DCLK1 expression in surgical specimens of 106 rectal cancer patients, including those who underwent preoperative CRT. The correlations between DCLK1 expression, and clinicopathological features and patient prognosis were then assessed. In rectal cancer patients treated with preoperative CRT, DCLK1 expression was significantly correlated with lymph node metastasis (p = 0.02) and poor cancer-specific survival (p = 0.049). However, in patients treated without preoperative therapy, no such correlation was found. DCLK1 expression can be associated with lymph node metastasis and poor cancer-specific survival in rectal cancer patients who receive CRT.