T3 Rectal Cancer Research Articles

Tolerability and safety of adjuvant chemoradiotherapy with S-1 after limited surgery for T1 or T2 lower rectal cancer.

Chemo-radiotherapy (CRT) after local excision for pT1 with high-risk features or pT2 rectal cancer is recommended as an optional treatment to achieve both curability and maintenance of quality of life. The aim of this study was to evaluate the short-term safety of combining limited surgery with adjuvant CRT for T1 or T2 lower rectal cancer. This was a multicenter, single-arm, prospective phase II trial. Patients diagnosed with lower rectal or anal canal cancer (clinical T1 or T2 with a maximum diameter of 30mm and N0 and M0) underwent local excision or endoscopic resection. Patients received CRT with S-1 (tegafur/gimeracil/oteracil) after confirmation of well- or moderately differentiated adenocarcinoma, and negative margins, and/or depth of submucosal invasion ≥ 1000µm or muscularis propria, and/or positive lymphovascular invasion, and/or tumor budding grade of 2/3. The primary endpoint was relapse-free survival. Secondary endpoints included overall and local relapse-free survival, safety, anal sphincter preservation rate, and anal function. Pathological diagnosis was T1 in 36 patients and T2 in 16 patients. Serious complications after surgery were not reported. The CRT completion rate per protocol was 86.5% (45/52). Thirty-two patients developed 54 events of CRT-related adverse events, including only one patient with a grade 3 event (stomatitis). The most common CRT-related adverse event was diarrhea (n = 14). No patients showed deterioration of anal function at 3years postoperatively. CRT with S-1 after limited surgery for T1 or T2 lower rectal cancer resulted in a low incidence of toxicities and maintenance of anal function.

Feasibility and outcomes of ERAS protocol in elective cT4 colorectal cancer patients: results from a single-center retrospective cohort study

BackgroundPrograms of Enhanced Recovery After Surgery reduces morbidity and shorten recovery in patients undergoing colorectal resections for cancer. Patients presenting with more advanced disease such as T4 cancers are frequently excluded from undergoing ERAS programs due to the difficulty in applying established protocols. The primary aim of this investigation was to evaluate the possibility of applying a validated ERAS protocol in patients undergoing colorectal resection for T4 colon and rectal cancer and to evaluate the short-term outcome.MethodsSingle-center, retrospective cohort study. All patients with a clinical diagnosis of stage T4 colorectal cancer undergoing surgery between November 2016 and January 2020 were treated following the institutional fast track protocol without exclusion. Short-term postoperative outcomes were compared to those of a control group treated with conventional care and that underwent surgical resection for T4 colorectal cancer at the same institution from January 2010 to October 2016. Data from both groups were collected retrospectively from a prospectively maintained database.ResultsEighty-two patients were diagnosed with T4 cancer, 49 patients were included in the ERAS cohort and 33 in the historical conventional care cohort. Both, the mean time of tolerance to solid food diet and postoperative length of stay were significantly shorter in the ERAS group than in the control group (3.14 ± 1.76 vs 4.8 ± 1.52; p < 0.0001 and 6.93 ± 3.76 vs 9.50 ± 4.83; p = 0.0084 respectively). No differences in perioperative complications were observed.ConclusionsResults from this cohort study from a single-center registry support the thesis that the adoption of the ERAS protocol is effective and applicable in patients with colorectal cancer clinically staged T4, reducing significantly their length of stay and time of tolerance to solid food diet, without affecting surgical postoperative outcomes.

Recurrence Outcomes Less Favorable in T1 Rectal Cancer than in T1 Colon Cancer.

With the implementation of screening programs worldwide, diagnosis of early-stage colorectal cancer steadily increased, including T1 cancer. Current T1 cancer treatment does not differ according to anatomic location. We therefore compared the disease-free survival of T1 cancer arising from the rectum versus the colon. The hospital-based study included subjects with T1 cancer at National Taiwan University Hospital from 2005 to 2014. Clinical, colonoscopy, and histopathology were reviewed for patients with a mean follow-up time of 7.1 (0.7-12.9) years. We conducted Kaplan-Meier analysis to compare the risk of recurrence by cancer location and Cox regression analysis to identify risk factors for T1 cancer recurrence. The final cohort included a total of 343 subjects with T1 cancer (mean age, 64.9± 11.7 years; 56.1% male), of whom 25 underwent endoscopic resection alone. Of the subjects who underwent surgery, 50 had lymph node metastasis and 268 did not. Kaplan-Meier analysis showed that the risk of recurrence was higher in T1 rectal cancer than T1 colon cancer (p=.022). Rectal location and larger neoplasm size were independent risk factors for recurrence, with hazard ratios of 4.84 (95% confidence interval, 1.18-19.92), and 1.32 (95% confidence interval, 1.06-1.65), respectively. The occurrence of advanced histology did not differ between T1 rectal and colon cancers (p=.58). T1 cancers arising from the rectum had less favorable recurrence outcomes than those arising from the colon. Further studies are needed to examine whether adjuvant radiotherapy or chemotherapy can reduce the risk of recurrence in T1 rectal cancer. Current T1 colorectal cancer treatment and surveillance do not differ according to anatomic location. Clinical, colonoscopy, and histopathology were reviewed for 343 patients with T1 cancer with a mean follow-up time of 7.1 years. Kaplan-Meier analysis showed that the risk of recurrence was higher in T1 rectal cancer than T1 colon cancer. Moreover, the rectal location was an independent risk factor for recurrence. T1 cancers from the rectum had less favorable recurrence outcomes than those arising from the colon. It is critical to clarify whether adjuvant therapy or more close surveillance can reduce recurrence risk in T1 rectal cancer.

Phase II trial of neoadjuvant mFOLFOX 6 with panitumumab (P) in T3 rectal cancer with clear mesorectal fascia (MRF) and KRAS, NRAS, BRAF, PI3KCA wild type (4WT). GEMCAD 1601 PIER trial.

3512 Background: Patients with advanced colorectal cancer with 4WT tumors achieve increased response rates with chemotherapy and anti-EGFR therapy as compared with chemotherapy alone. In clinically staged (c) T3 rectal cancer neoadjuvant oxaliplatin/fluoropyrimidine combination has shown to induce encouraging pathological complete response (pCR). We hypothesize that combining FOLFOX and P could improve outcomes in 4WT tumors. Methods: PIER was an investigator-initiated phase II, single-arm, multicentre clinical trial to evaluate the safety and efficacy of neoadjuvant mFOLFOX6 with P in pts &lt; 75-y, with 4WT rectal cancer of the middle third staged as T3 by centrally-reviewed magnetic resonance imaging (MRI) and clear MRF, who were candidate for a R0 resection with sphincter preservation surgery. Pts received 6 cycles and underwent re-staging with MRI and sigmoidoscopy. Pts without progression underwent total mesorectal excision 4 weeks after the last cycle. Patients with progression were treated with pre-op chemoradiotherapy. The primary endpoint was pCR. The study followed a 2-Stage Simon’s MiniMax design (P0 of 16%, P1 of 35%, alpha and beta of 0.1). The target sample size was 35 patients and if 9 or more achieved a pCR, the results would be compatible with efficacy. We present primary and early secondary endpoints. Results: Between 9/2017 and 6/2020, 90 patients were screened (56 excluded; 42 were excluded due to mutations, 12 were excluded due to discrepancies with central review of radiology) of whom 34 were enrolled. In the ITT population a pCR was observed in 11 pts (32.3%; [95% CI 17.39-50.53]) and a near-complete pathological response (Mandard 1+2) was observed 17 pts (52.9%). Clinical complete or near complete response was achieved in 50% and there were no progressions. R0 resection rate and pathological circumferential resection margin neg- were 100%. Full compliance with induction was 88%. Neoadjuvant G3/4 toxicity occurred in 54% and was consistent with FOLFOX/P safety profile. G3/4 postoperative related toxicity was 19% with one reoperation. Conclusions: The study met the threshold for efficacy. mFOLFOX6 with P as neoadjuvant therapy can be effective and safe without unexpected toxicities in mrT3, clear MRF and 4WT rectal cancer and resulted in a higher rate of pCR compared with our previous series (GEMCAD 0801; The Oncologist 2014) in a similar molecular-unselected population. This study was funded by Amgen S.A. Clinical trial information: NCT03000374.

Accuracy of High Resolution Multidetector Computed Tomography in the Local Staging of Rectal Cancer

Abstract Background Magnetic resonance imaging (MRI) is the gold standard for local staging of rectal cancer. Advanced computed tomography (CT) machines are now capable of high-resolution images of rectal cancer and utilized for CT perfusion. The possibility of local staging of rectal cancer by CT needs to be explored. Purpose The aim of the study is to evaluate accuracy of high-resolution CT for local rectal cancer staging. Methods A high-resolution CT was performed for local staging of rectal cancer in our study group of 93 patients, where 64 underwent primary surgery and 29 underwent surgery post neoadjuvant chemoradiotherapy (NACRT). Results In differentiating stages T2-and-less than T2 from T3–T4 rectal cancer, accuracy, sensitivity, specificity, and kappa score in overall patients were 91%, 87%, 94%, and 0.8; in primary surgery group were 89%, 76%, 94%, and 0.7; in NACRT group were 97%, 100%, 94%, and 0.9; in low rectal group were 94%, 89%, 97%, and 0.82, respectively. Conclusion High resolution CT is an accurate tool for local staging of rectal cancer.

T1 Rectal Adenocarcinoma: a Different Way to Measure Tumoral Invasion Based on the Healthy Residual Submucosa with Its Prognosis and Therapeutic Implications

BackgroundSurgical treatment of early rectal cancer T1 is either local excision or total mesorectal excision. The choice of surgery is based on the risk of metastatic lymph node involvement. The most important factor to consider is the degree of submucosal invasion. We present a different way to measure tumoral invasion derived from the measurement of the healthy residual submucosa with its prognosis and therapeutic implications MethodsObservational study of tumor submucosal invasion in patients undergoing transanal endoscopic microsurgery was conducted. Parameters evaluated are submucosal invasion, measuring the healthy residual submucosa at the point of maximum invasion; macroscopic morphology of the tumor; presence of muscularis mucosa, muscularis propria, and measurement of submucosa in the tumor area and the healthy area. The classification proposed is compared with the ones previously published. ResultsEighty consecutive patients diagnosed with T1 rectal cancer underwent transanal endoscopic microsurgery. Seventeen tumors (21.3%) were polypoid. En bloc resection was achieved in 77 (96.3%). The muscularis mucosa was present in 28 (35%), and the muscularis propria in 77 (96.3%) (p < 0.001). The healthy residual submucosa in the tumor area measured 2,343 ± 1,869 μm. Agreement was moderate with the Kikuchi classification (kappa 0.58) and very good with the Kudo classification (kappa 0.87). ConclusionsWe describe a method for measuring submucosal invasion in T1 rectal cancer which does not depend on the morphology of the lesion or on the presence of the muscularis mucosa. It can be applied to all T1 classifications of the digestive tract in which the muscularis propria is present.

MRI associated biomarker analysis for diagnosis of lymph node metastasis in T1-2 stage rectal cancer

Objective: To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment. Methods: Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors. Results: Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis (P<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology (P=0.002), including mucus or not (P<0.001), and MR-N evaluation (P<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95%CI: 0.720~0.852). Conclusions: Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.

Age-related differences in morbidity and mortality after surgery for primary clinical T4 and locally recurrent rectal cancer.

Outcomes in elderly patients (≥75years) with non-advanced colorectal cancer have improved. It is unclear whether this is also true for elderly patients with clinical T4 rectal cancer (cT4RC) or locally recurrent rectal cancer (LRRC). We aimed to compare age-related differences in morbidity and mortality after curative treatment for cT4RC and LRRC. All cT4RC and LRRC patients without distant metastasis who underwent curative surgery between 2005 and 2017 in the Catharina Hospital (Eindhoven, The Netherlands) were included. Morbidity and mortality were evaluated based on age (<75 and ≥75years) and date of surgery (2005-2011 and 2012-2017). Overall, 72 of 474 (15.2%) cT4RC and 53 of 293 (18.1%) LRRC patients were ≥75years. Nosignificantdifferences in the incidence of Clavien-Dindo I-IV complications were observed between age groups. However, in elderly cT4RC patients, cerebrovascular accidents occurred more frequently (4.2% vs. 0.5%, P=0.03). Between 2005-2011 and 2012-2017, 30-day mortality improved from 7.5% to 3.1% and from 10.0% to 0.0% in elderly cT4RC and LRRC patients, respectively. The 1-year mortality during 2012-2017 was worse in elderly than in younger patients (28.1% vs. 6.2%, P=0.001 for cT4RC and 27.3% vs. 13.8%, P=0.06 for LRRC). In elderly cT4RC and LRRC patients, 44.4% and 46.2% died due to non-cancer-related causes, while only 27.8% and 23.1% died due to disease recurrence, respectively. Although the 30-day mortality in elderly cT4RC and LRRC patients improved after curative treatment, the 1-year mortality in elderly patients continued to be high, which requires more awareness for the elderly after hospitalization.

Robotic surgery for clinical T4 rectal cancer: short- and long-term outcomes.

The optimal surgical approach for clinical T4 (cT4) rectal cancer is unknown. This study was conducted to clarify short- and long-term outcomes of robotic surgery for cT4 rectal cancer. In our retrospective cohort study, we enrolled patients who underwent robotic surgery for cT4 rectal cancer within 15cm from the anal verge between 2011 and 2018. The short- and long-term outcomes were evaluated. Of a total of 122 eligible patients, 70 (57%) had cT4a tumors and 52 (43%) had cT4b tumors. Thirty-five patients (29%) had distant metastasis and 21 (17%) underwent preoperative chemoradiotherapy. Thirty-four patients (28%) underwent combined resection of adjacent organs and 43 (35%) underwent lateral lymph node dissection. The median operative time was 288min and the median blood loss was 11ml. No patients required conversion to open surgery. The incidences of postoperative complications of grades II, III, and IV or more according to the Clavien-Dindo classification were 17.2%, 3.5%, and 0%, respectively. Seventy-three patients (60%) had pathological T4 tumors, and the incidence of positive resection margins was 4.9%. The median follow-up time was 42.9months. The 3-year overall survival, disease-free survival, and cumulative local recurrence rates were 87.5%, 70.4%, and 4.0%, respectively. The short- and long-term outcomes of robotic surgery for cT4 rectal cancer were favorable. Robotic surgery is considered to be a useful approach for cT4 rectal cancer.

Intentional Watch &amp;amp; Wait or Organ Preservation Following Neoadjuvant Chemoradiotherapy Plus Consolidation Capeox for Mri-Defined Low-Risk Rectal Cancer: Findings from a Prospective Phase 2 Trial (PKUCH-R01 Trial, NCT02860234)

Background: Clinical T2 or early T3 rectal cancers can be managed by definitive rectal resection and achieve high clinical complete response (cCR) with chemoradiation, thereby facilitating an intentional watch-and-wait (W&W) or organ-preservation strategy. We assessed the efficacy of neoadjuvant chemoradiation plus consolidation CAPEOX in MRI-defined low-risk rectal cancer to ascertain the proportion of patients who can achieve cCR and receive a W&W or organ-preservation approach. Methods: This prospective, single-arm, phase 2 trial enrolled patients with cT2/T3a/T3b low-risk rectal cancers that were pre-staged by magnetic resonance imaging (MRI), after excluding patients with local or systemic high-risk factors, such as mesorectal fascia, extramural vessel invasion, or mucinous differentiation. All patients concurrently received chemoradiation, followed by four 3-week cycles of the CAPEOX regimen. Following reassessment by the multidisciplinary team, patients with cCR or near-cCR received W&W/organ-preservation surgery. The primary endpoint was the 3-year organ-preservation rate. Findings: Of the 64 participants, 58 completed the treatment, with 6·4% and 33·9% grade 3–4 toxicities in the radiotherapy and consolidation CAPEOX phases, respectively, during a median follow-up of 32·7 (interquartile range [IQR] 4·3–60·3) months. Initial cCR, near-cCR, and non-cCR occurred in 33 (51·5%), 13 (20·3%), and 18 (28·2%) patients, respectively. Of the 31 cCR and seven near-cCR cases managed by WW 8 and 20 patients received local excision and radical resection, respectively, including six of seven patients with local regrowth salvage. One patient died of postoperative complications. Lung metastasis occurred in one patient with W&W and one patient with local excision, with no local recurrence and an estimated 3-year organ-preservation rate of 68·8%. The estimated 3-year CSS, non-regrowth disease-free survival, and stoma-free survival were 95·8%, 93·8%, and 84·3%, respectively. Interpretation: Chemoradiotherapy with consolidation CAPEOX for MRI-defined low-risk rectal cancer achieves high cCR and organ-preservation rate. Intentional W&W might be a safe strategy for this patient subgroup. Trial Registration: This study is registered at ClinicalTrials.gov with the identifier NCT02860234. Funding: Supported by The Beijing Municipal Science & Technology Commission Capital Clinical Research Special Fund (Z151100004015105); National Natural Science Foundation of China (81773214); Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support, code: (ZYLX202116) Declaration of Interest: None to declare. Ethical Approval: The protocol and the later amendments were approved by the ethics committee of Peking University Cancer Hospital on August 06, 2016 and on December 17, 2018, respectively.

Submucosal Enhancing Stripe as a Contrast Material-enhanced MRI-based Imaging Feature for the Differentiation of Stage T0-T1 from Early T2 Rectal Cancers.

Background Accurate differentiation of stage T0-T1 rectal tumors from stage T2 rectal tumors facilitates the selection of appropriate surgical treatment. MRI is a recommended technique for local staging, but its ability to distinguish T1 from T2 tumors is poor. Purpose To explore the value of a submucosal enhancing stripe (SES), an uninterrupted enhancing band between the rectal tumor and the muscular layer on contrast material-enhanced T1-weighted images, as a potential imaging feature to differentiate T0-T1 from T2 rectal tumors. Materials and Methods This retrospective study included patients with pT0-T1 and pT2 rectal tumors who underwent pretreatment MRI and rectal tumor resection between January 2012 and November 2019. Two radiologists independently evaluated tumor characteristics (SES; status of muscularis propria [SMP]; and tumor shape, location, and size) at MRI. The associations of clinical and imaging characteristics with stage T0-T1 or T2 tumors were assessed, β values were calculated, and predictive models were built. The diagnostic accuracies for the differentiation of T0-T1 tumors from T2 tumors with SES and SMP were compared. Results Data from 431 patients (mean age, 60 years ± 10 [standard deviation]; 261 men) were evaluated. SES (β = 3.9; 95% CI: 3.1, 4.7; P < .001), SMP (β = 1.3; 95% CI: 0.7, 1.9; P < .001), and carpetlike shape (β = 1.6; 95% CI: 0.5, 2.8; P = .01) were independent factors distinguishing T0-T1 tumors from T2 tumors. The diagnostic accuracy was 87% (95% CI: 84, 90; 376 of 431) for SES and 67% (95% CI: 63, 72; 290 of 431) for SMP (P < .001). Conclusion Submucosal enhancing stripe (SES) at contrasted-enhanced MRI, status of muscularis propria (SMP) on T2-weighted images, and tumor shape can serve as independent imaging features to differentiate stage T0-T1 rectal tumors from stage T2 rectal tumors. Moreover, SES is a more accurate feature than is SMP. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Diagnostic Value of Multi-Parameter MRI in Sub-Stage of T3 Rectal Cancer

The paper aims to explore the diagnostic value of multi-parameter MRI in sub-stage of T3 rectal cancer. According to the results of clear pathological evaluation, 52 patients were divided into T3I and T3II groups according to the maximum mesorectum depth of tumor infiltration. The χ2 test was used to compare the differences of the overall morphology index, morphological index of the extramural strips, type of time-signal intensity curve (TIC), and the location index of DWI diffusion-limited distribution between the two groups. The independent sample t was used to test and compare the differences in semi-quantitative parameters of DCE between the two lesion groups. The pathological results were used as the dependent variables, the indicators mentioned above with statistical differences were used as the independent variables, and a Logistic regression model was established to construct joint parameters and evaluate its diagnostic efficacy. The differences in the circumferential diameter of lesions and morphological index of extramural strips (p &lt; 0.01), and DWI diffusion restricted distribution index (p &lt; 0.01) of the two groups were statistically significant. The difference in the DCE semiquantitative parameter early enhancement ratio (EER) (p &lt; 0.01) between the two groups. The maximum Youden index of a newly-constructed parameter diagnosis combination: circumferential diameter of lesions + extramural strips + distribution locations of limited diffusion on DWI + EER was 0.73, the area under receiver operating characteristic curve(ROC) was 0.887 and the diagnostic sensitivity and specificity were 85.24% and 87.34%. By making full use of multi-parameter information, combined with morphological index of extramural strips, circumferential diameter of lesions, EER and distribution locations of the diffusion-limited of DWI as evaluation indexes, it can provide a high diagnostic efficiency for the sub-stage of T3 rectal cancer.

Local excision for T1 rectal tumours: are we getting better?

The objective was to assess the effect of three different surgical treatments for T1 rectal tumours, radical resection (RR), open local excision (open LE) and laparoscopic local excision (laparoscopic LE), on overall survival (OS). Adults from the National Cancer Database (2008-2016) with a diagnosis of T1 rectal cancer were stratified by treatment type (LE vs RR). We assumed that laparoscopic LE equates to transanal minimally invasive surgery (TAMIS) or transanal endoscopic microsurgery. The primary outcome was 5-year OS. Subgroup analyses of the LE group stratified by time period [2008-2010 (before TAMIS) vs 2011-2016 (after TAMIS)] and approach (laparoscopic vs open) were performed. Among 10053 patients, 6623 (65.88%) underwent LE (74.33% laparoscopic LE vs 25.67% open LE) and 3430 (34.12%) RR. The use of LE increased from 52.69% in 2008 to 69.47% in 2016, whereas RR decreased (P<0.001). In unadjusted analysis, there was no significant difference in 5-year OS between the LE and RR groups (P=0.639) and between the two LE time periods (P=0.509), which was consistent with the adjusted analysis (LE vs RR, hazard ratio 1.05, 95% CI 0.92-1.20, P=0.468; 2008-2010 LE vs 2011-2016 LE, hazard ratio 1.09, 95% CI 0.92-1.29, P=0.321). Laparoscopic LE was associated with improved OS in the unadjusted analysis only (P=0.006), compared to the open LE group (hazard ratio 0.94, 95% CI 0.78-1.12, P=0.495). This study supports the use of a LE approach for T1 rectal tumours as a strategy to reduce surgical morbidity without compromising survival.

Oncological Outcomes of Transanal Endoscopic Microsurgery Plus Adjuvant Chemoradiotherapy for Patients with High-Risk T1 and T2 Rectal Cancer.

Background: Radical surgery is recommended for high-risk pathological stage T1 (pT1) or pT2 rectal cancer after transanal endoscopic microsurgery (TEM). However, in clinical practice, many patients may unfit or decline radical surgery. In recent years, adjuvant chemoradiotherapy (CRT) after TEM was considered as an alternative to radical surgery for these patients. This study aimed to assess oncological outcomes of adjuvant CRT after TEM for high-risk early rectal cancer. Materials and Methods: We collected retrospectively data of 97 patients who underwent TEM with pT1 and pT2 between January 2008 and December 2018. Of these, 35 patients were excluded. Of the remaining 62 patients, 42 were managed by TEM alone and 20 by TEM plus adjuvant CRT. Demographics, recurrence, and survival were analyzed between the two groups. Results: At a median follow-up of 52.5 months, the 3-year local recurrence-free survival and disease-free survival (DFS) in TEM alone group were significantly lower than those in TEM+CRT group (66.6% versus 93.3%, P = .035; 63.7% versus 93.3%, P = .022). Although the 3-year overall survival in TEM+CRT group was higher than TEM alone group (100% versus 83.3%), the difference was not statistically significant (P = .13). The local recurrence rate in TEM alone was 31%, compared with 5% in TEM+CRT group (P = .025). Multivariate analysis showed that adjuvant CRT was an independent prognostic factor for DFS (hazard ratio: 0.094; 95% confidence interval: 0.001-0.764; P = .027). Conclusions: Our study suggests that adjuvant CRT after TEM may be an alternative for pT1 high-risk and T2 rectal cancer who are not suitable or unwilling to undergo salvage radical surgery.

LBA21 Neoadjuvant mFOLFIRINOX and preoperative chemoradiation (CRT) versus preoperative CRT in patients with T3-4 rectal cancer: Surgical and quality of life results of PRODIGE 23 phase III trial

LBA21 Neoadjuvant mFOLFIRINOX and preoperative chemoradiation (CRT) versus preoperative CRT in patients with T3-4 rectal cancer: Surgical and quality of life results of PRODIGE 23 phase III trial

Evaluation of the Extent of Mesorectal Invasion and Mesorectal Fascia Involvement in Patients with T3 Rectal Cancer With 2-D and 3-D Transrectal Ultrasound: A Pilot Comparison Study With Magnetic Resonance Imaging Findings

The aim of this study was to determine the value of 2-D and 3-D transrectal ultrasound (TRUS) in assessing the extent of mesorectal invasion (EMI) and mesorectal fascia involvement (MRF+) in patients with T3 rectal tumours. We retrospectively evaluated 80 patients with T3 stage rectal cancer who were pre-operatively evaluated by 2-D and 3-D TRUS before neoadjuvant chemoradiotherapy by using magnetic resonance imaging (MRI) as a reference standard. The T3 stage was subdivided into T3 ab (EMI ≤5 mm) and T3 cd (EMI >5 mm). The consistency assessment of the T3 sub-staging and MRF+ was compared between 2-D and 3-D TRUS using Cohen's kappa statistic. The concordance of the T3 sub-staging based on EMI was excellent between the 3-D TRUS and MRI (κ = 0.84) and good between the 2-D TRUS and MRI (κ = 0.67). For the assessment of MRF+ (κ = 0.82), 3-D TRUS and MRI showed excellent concordance. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 3-D TRUS for MRF+ assessment was 95.3%, 86.5%, 89.1% and 94.1%, respectively. The agreement between 3-D TRUS and MRI for the assessment of T3 sub-staging and MRF status was better in low rectal cancer (both κ = 0.85) than in middle (κ = 0.79 and 0.77) rectal cancer. Compared with MRI, 3-D TRUS has more advantages in the sub-staging of T3 rectal cancer and the assessment of MRF+ than those of 2-D TRUS, especially in low rectal cancer. For patients with T3 rectal cancer, 3-D TRUS may well complement MRI for selecting the appropriate treatment.

Feasibility of laparoscopic-assisted transanal pelvic exenteration in locally advanced rectal cancer with anterior invasion.

Transanal (Ta) pelvic exenteration is a promising, minimally invasive method for treating locally advanced colorectal cancer. However, since it is technically difficult to perform, Ta pelvic exenteration is rarely reported in locally advanced T4 rectal cancer cases. The aim of this study was to evaluate the feasibility of transabdominal laparoscopy-assisted Ta pelvic exenteration. Six patients (4 males and 2 females) had laparoscopy-assisted Ta total or posterior pelvic exenteration for locally advanced or recurrent colorectal cancer cases at the Nagasaki University Hospital between September 2018 and August 2019. Clinical and pathological outcomes were measured and analyzed. The median operation time and intraoperative blood loss were 481 (range 456-709) minutes and 352.5 (range 257-1660) ml, respectively. R0 resection was achieved in all cases, and no patient required open surgery. Two patients had grade 3 complications (Clavien-Dindo) or higher. There was no mortality, and no reoperation was required. The results suggest that laparoscopic-assisted Ta pelvic exenteration is an acceptable procedure, may help overcome the current technical difficulties, and may improve outcomes in patients with locally advanced rectal cancer.

Incidence and Pattern of Nodal Metastasis in Colon and Rectal Cancer: a Study of 1012 Cases from Thailand

Objective: Lymph node (LN) metastasis is a key to determine prognosis and adjuvant treatment for resectable colorectal cancer. This study aimed to determine and compare the incidence and pattern of LN metastasis between colon cancer and rectal cancer.Methods: Medical and pathological reports of patients with stage I-III colorectal adenocarcinoma undergoing oncological resection between 2009 and 2013 at the Faculty of Medicine Siriraj Hospital were reviewed. The incidence and pattern of LN metastasis related to tumor staging between colon cancer and rectal cancer were analyzed.Results: This study included 1012 cases (502 colon cancer and 510 rectal cancer). Compared with rectal specimens, colonic specimens had a larger tumor size (5.8 cm vs 5.0 cm; P&lt;0.001), more T4 lesion (24% vs 6.3%; P&lt;0.001) and more LNs harvested (24 vs 18; P&lt;0.001). Nodal metastases were found in 552 specimens (54.5%). The rate of LN metastasis was 14.3% for T1 tumors, 25.6% for T2 tumors, 61.2% for T3 tumors, and 65.6% for T4 tumors. There was no significant difference in the overall rate of nodal metastasis between colon cancer and rectal cancer (52.6% vs 56.5%; P=0.22), but rectal cancer had more N2 staging (31% vs 22.5%; P=0.002). Rectal cancer yielded more median number of positive LN (4 vs 3; P=0.002) with a greater LN ratio (0.22 vs 0.12; P&lt;0.001) than colon cancer. Based on the depth of tumor invasion, T3 rectal cancer had a significantly higher rate of LN metastasis (66.8% vs 55.7%; P=0.004) and a greater LN ratio (0.23 vs 0.10; P&lt;0.001) than T3 colon cancer.Conclusion: Although colon cancer had a larger tumor size and a higher percentage of deeper invasion, rectal cancer were associated with a higher number of positive LN, more N2 status and a greater LN ratio - especially T3 lesion.

Single-port robotic transanal minimally invasive surgery (SPR-TAMIS) approach to local excision of rectal tumors.

Trans-anal excision is the surgical treatment of choice for endoscopically unresectable rectal polyps, early rectal cancers, small carcinoid tumors, and other low-risk tumors. The single-port robotic (SPR) platform is the newest development in robotic surgery capable of performing trans-anal minimally invasive surgery (TAMIS). In theory, the single incision design would naturally lend itself to the size limitation of the anal canal, but in practice, this method has not been tested. Herein we describe the techniques and first reports of performing TAMIS using the SPR platform. We describe in detail how to perform the SPR-TAMIS technique using lessons and experience gained from performing this on five patients who had endoscopically unresectable rectal polyps or T1 rectal cancers. Each patient was followed for a minimum of 30days and was seen in clinic post-operatively. A retrospective chart review was performed to obtain information on technical success, anatomic measurements, and reported complications. The SPR TAMIS was successfully performed on all five patients without any reported complications. All underwent a non-piecemeal excision and had return of regular bowel function at 30-day follow-up. All patients were discharged from the hospital the same day as their operation. SPR-TAMIS is a novel, safe, and feasible procedure capable of achieving non-piecemeal resections of low-risk rectal tumors. Further study needs to be conducted to determine complication rates, functional and oncologic outcomes, and ensure the long-term safety profile.

Risk Factors for Severe Complications After Laparoscopic Surgery for T3 or T4 Rectal Cancer for Chinese Patients: Experience from a Single Center.

BackgroundPatients with rectal cancer are usually at advanced stage with or beyond serosa invasion in China. Severe complications after laparoscopic rectal surgery leads to prolonged hospitalization and high medical cost. This study aimed to explore risk factors for severe complications after laparoscopic surgery of T3 or T4 rectal cancer.Material/MethodsA total of 287 patients diagnosed with T3 or T4 rectal cancer were enrolled from the Department of Gastrointestinal Surgery of Anhui Provincial Hospital from February 2012 to February 2017. Univariate analysis and multivariable logistic regression model were used to analyze the risk factors for severe complications (Clavien-Dindo grade ≥III) after laparoscopic surgery.ResultsEighteen patients (6.25%) had severe complications; 15 patients were categorized as Clavien-Dindo grade III, and 3 patients were categorized as Clavien-Dindo grade IV. Univariate analysis showed that male gender, high preoperative white blood cells (WBC), diabetes mellitus, pulmonary dysfunction, and tumor distance from anus were associated with increased risk of severe complications after laparoscopic surgery for rectal cancer. Multivariate analysis showed that preoperative WBC ≥6.9×109/L (OR=5.54 (1.58–19.45), P=0.008), diabetes mellitus (OR=13.07 (3.31–51.67), P=0.000) and pulmonary dysfunction (OR=7.75 (1.69–35.63), P=0.008) were independent risk factors for postoperative severe complications.ConclusionsPreoperative high white blood cells, diabetes mellitus and pulmonary dysfunction were independent risk factors for severe complications after laparoscopic surgery for T3 or T4 rectal cancer.