Surgical quality assessment for the prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for nonmetastatic right colon cancer (PIONEER study).

BACKGROUND: The modified complete mesocolic excision (mCME) procedure for right-sided colon cancer is a tailored approach based on the original complete mesocolic excision (CME) methodology. Limited studies evaluated the safety and feasibility of laparoscopic mCME using objective surgical quality assessments in patients with right colon cancer. The objectives of the PIONEER study were to evaluate oncologic outcomes after laparoscopic mCME and to identify optimal clinically relevant endpoints and values for standardizing laparoscopic right colon cancer surgery based on short-term outcomes of procedures performed by expert laparoscopic surgeons. MATERIALS AND METHODS: This is an ongoing prospective, multi-institutional, single-arm study conducted at five tertiary colorectal cancer centers in South Korea. Study registrants included 250 patients scheduled for laparoscopic mCME with right-sided colon adenocarcinoma (from the appendix to the proximal half of the transverse colon). The primary endpoint was 3-year disease-free survival. Secondary outcomes included 3-year overall survival, incidence of morbidity in the first 4 weeks postoperatively, completeness of mCME, central radicality, and distribution of metastatic lymph nodes. Survival data will be available after the final follow-up date (June 2024). RESULTS: The postoperative complication rate was 12.9%, with a major complication rate of 2.7%. In 87% of patients, central radicality was achieved with dissection at or beyond the level of complete exposure of the superior mesenteric vein. Mesocolic plane resection with an intact mesocolon was achieved in 75.9% of patients, as assessed through photographs. Metastatic lymph node distribution varied by tumor location and extent. Seven optimal clinically relevant endpoints and values were identified based on the analysis of complications in low-risk patients. CONCLUSIONS: Laparoscopic mCME for right-sided colon cancer produced favorable short-term postoperative outcomes. The identified optimal clinically relevant endpoints and values can serve as a reference for evaluating surgical performance of this procedure.

A qualitative exploration of exercise motivation among colorectal cancer survivors: an application of the theory of planned behavior.

PURPOSE: The purpose of this qualitative study was to use semi-structured interviews and thematic analysis to elicit key influencing factors (i.e., behavioral, normative, and control beliefs) related to physical activity and exercise in colorectal cancer survivors. METHODS: Colorectal cancer survivors (N = 17) were recruited from exercise programs designed for colorectal cancer survivors at the Yonsei Cancer Center, Seoul, South Korea. A purposive sampling method was used. Interview questions were informed by the theory of planned behavior (TPB). Semi-structured face-to-face interviews were conducted, and open-ended questions addressed the research question. Interviews were transcribed verbatim and analyzed using thematic analysis. RESULTS: Participants were on average 2.2 years post-treatment. The mean age of the sample was 55.9 years. Key behavioral, normative, and control beliefs emerged in the data. For behavioral beliefs, colorectal cancer survivors believed that exercise would result in physical and psychological improvements, and improve their bowel problems. For normative beliefs, most colorectal cancer survivors wanted their oncologists' approval for participation of exercise. Family members, more specifically the spouse, were also influencing factors for colorectal cancer survivors adopting physical activity. The most frequently mentioned control belief was that supervised exercise with an exercise specialist made exercise participation easier. CONCLUSIONS AND IMPLICATIONS: Beliefs identified in this study can inform TPB-based physical activity interventions tailored for colorectal cancer survivors. While information alone may not lead to behavior change, integrating these beliefs with other influential factors can potentially enhance intervention efficacy and promote physical activity in this population.

Long-term bowel functional outcomes following anal sphincter-preserving surgery for upper and middle rectal cancer: a single-center longitudinal study.

PURPOSE: Despite advances in neoadjuvant chemoradiotherapy and anal sphincter-preserving surgery for rectal cancer, bowel dysfunction is still unavoidable and negatively affects patients' quality of life. In this longitudinal study, we aimed to investigate the changes in bowel function with follow-up time and the effect of neoadjuvant chemoradiotherapy on bowel function following low anterior resection for rectal cancer. METHODS: In this study, 171 patients with upper or middle rectal cancer who underwent low anterior resection between 2012 and 2018 were included. Bowel function was assessed longitudinally with Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores every 6 months after restoration of bowel continuity. Patients with at least 2 follow-up visits were included. RESULTS: Overall, 100 patients received neoadjuvant chemoradiotherapy. Urgency, soilage, and fecal incontinence were noted within 24 months in the patients treated with neoadjuvant chemoradiotherapy. After 2 years of follow-up, significant bowel dysfunction and fecal incontinence were observed in the neoadjuvant chemoradiotherapy group. Low tumor level and neoadjuvant chemoradiotherapy were associated with delayed bowel dysfunction. CONCLUSION: Neoadjuvant chemoradiotherapy in combination with low tumor level was significantly associated with delayed bowel dysfunction even after 2 years of follow-up. Therefore, careful selection and discussion with patients are paramount.

Active involvement of patients, radiation oncologists, and surgeons in a multidisciplinary team approach: Guiding local therapy in recurrent, metastatic rectal cancer.

BACKGROUND: Despite the extensive implementation of an organized multidisciplinary team (MDT) approach in cancer treatment, there is little evidence regarding the optimal format of MDT. We aimed to investigate the impact of patient participation in MDT care on the actual application rate of metastasis-directed local therapy. METHODS: We identified all 1211 patients with locally advanced rectal cancer treated with neoadjuvant radiochemotherapy at a single institution from 2006 to 2018. Practice patterns, tumor burden and OMD state were analyzed in recurrent, metastatic cases. RESULTS: With a median follow-up of 60.7 months, 281 patients developed metastases, and 96 (34.2%), 92 (32.7%), and 93 (33.1%) patients had 1, 2-5, and >5 lesions, respectively. In our study, 27.1% were managed in the MDT clinic that mandated the participation of at least four to five board-certified multidisciplinary experts and patients in decision-making processes, while the rest were managed through diverse MDT approaches such as conferences, tumor board meetings, and discussions conducted via phone calls or email. Management in MDT clinic was significantly associated with more use of radiotherapy (p = 0.003) and more sessions of local therapy (p < 0.001). At the time of MDT clinic, the number of lesions was 1, 2-5, and >5 in 9 (13.6%), 35 (53.1%), and 19 (28.8%) patients, respectively. The most common states were repeat OMD (28.8%) and de novo OMD (27.3%), followed by oligoprogression (15%) and induced OMD (10.6%). CONCLUSION: Our findings suggest that active involvement of patients and radiation oncologists, and surgeons in MDT care has boosted the probability of using local therapies for various types of OMD throughout the course of the disease.

Pretreatment MRI-detected extramural venous invasion as a prognostic and predictive biomarker for neoadjuvant chemoradiotherapy in non-metastatic rectal cancer: a propensity score matched analysis.

OBJECTIVES: This study evaluated pretreatment magnetic resonance imaging (MRI)-detected extramural venous invasion (pmrEMVI) as a predictor of survival after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Medical records of 1184 patients with rectal adenocarcinoma who underwent TME between January 2011 and December 2016 were reviewed. MRI data were collected from a computerized radiologic database. Cox proportional hazards analysis was used to assess local, systemic recurrence, and disease-free survival risk based on pretreatment MRI-assessed tumor characteristics. After propensity score matching (PSM) for pretreatment MRI features, nCRT therapeutic outcomes according to pmrEMVI status were evaluated. Cox proportional hazards analysis was used to identify risk factors for early recurrence in patients receiving nCRT. RESULTS: Median follow-up was 62.8 months. Among all patients, the presence of pmrEMVI was significantly associated with worse disease-free survival (DFS; HR 1.827, 95% CI 1.285-2.597, p = 0.001) and systemic recurrence (HR 2.080, 95% CI 1.400-3.090, p < 0.001) but not local recurrence. Among patients with pmrEMVI, nCRT provided no benefit for oncological outcomes before or after PSM. Furthermore, pmrEMVI( +) was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT. CONCLUSIONS: pmrEMVI is a poor prognostic factor for DFS and SR in patients with non-metastatic rectal cancer and also serves as a predictive biomarker of poor DFS and SR following nCRT in LARC. Therefore, for patients who are positive for pmrEMVI, consideration of alternative treatment strategies may be warranted. CLINICAL RELEVANCE STATEMENT: This study demonstrated the usefulness of pmrEMVI as a predictive biomarker for nCRT, which may assist in initial treatment decision-making in patients with non-metastatic rectal cancer. KEY POINTS: • Pretreatment MRI-detected extramural venous invasion (pmrEMVI) was significantly associated with worse disease-free survival and systemic recurrence in patients with non-metastatic rectal cancer. • pmrEMVI is a predictive biomarker of poor DFS following nCRT in patients with LARC. • The presence of pmrEMVI was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

Postchemoradiation magnetic resonance imaging circumferential resection margin predicts treatment failure after multidisciplinary directed sphincter preservation in low rectal cancer.

BACKGROUND: This study aimed to review the magnetic resonance imaging (MRI) features of patients with low rectal cancer (LRC) undergoing preoperative chemoradiotherapy (CRT) and investigate the risk factors for treatment failure after sphincter preserving surgery following preoperative CRT based on multidisciplinary approach. OBJECTIVES: Patients who underwent standard CRT and sphincter preserving radical surgery for LRC between January 2000 and December 2011 were retrospectively reviewed. Sphincter preservation failure (SPF) was defined as any one of the following: positive pathologic circumferential resection margin, local recurrence, failure to repair ileostomy, or permanent stoma formation due to anastomotic complications. RESULTS: Among the 191 patients, there were no overall significant differences between sphincter preservation success (n = 161) and SPF (n = 30) groups. SPF group showed a higher MRI circumferential resection margins (mrCRM) positive rate before and after CRT (before CRT: 33.3% vs. 16.1%, p = 0.027; after CRT: 23.3% vs. 6.2%, p = 0.002). Multivariate analysis showed that only mrCRM after CRT was associated with SPF (hazard ratio = 4.596, p = 0.005). SPF group showed worse 5-year cancer-specific survival (51% vs. 92.7%, p < 0.001). CONCLUSIONS: MRI-based assessment of the tumor after CRT plays a crucial role in predicting the success and feasibility of sphincter preservation as well as oncological outcomes in patients with LRC.

Short-Term Outcomes and Cost-Effectiveness between Long-Course Chemoradiation and Short-Course Radiotherapy for Locally Advanced Rectal Cancer.

PURPOSE: Long-course chemoradiotherapy (LCRT) has been widely recommended in a majority of rectal cancer patients. Recently, encouraging data on short-course radiotherapy (SCRT) for rectal cancer has emerged. In this study, we aimed to compare these two methods in terms of short-term outcomes and cost analysis under the Korean medical insurance system. MATERIALS AND METHODS: Sixty-two patients with high-risk rectal cancer, who underwent either SCRT or LCRT followed by total mesorectal excision (TME), were classified into two groups. Twenty-seven patients received 5 Gy×5 with two cycles of XELOX (capecitabine 1000 mg/m² and oxaliplatin 130 mg/m² every 3 weeks) followed by TME (SCRT group). Thirty-five patients received capecitabine-based LCRT followed by TME (LCRT group). Short-term outcomes and cost estimation were assessed between the two groups. RESULTS: Pathological complete response was achieved in 18.5% and 5.7% of patients in the SCRT and LCRT groups, respectively (p=0.223). The 2-year recurrence-free survival rate did not show significant difference between the two groups (SCRT vs. LCRT: 91.9% vs. 76.2%, p=0.394). The average total cost per patient for SCRT was 18% lower for inpatient treatment (SCRT vs. LCRT: $18787 vs. $22203, p<0.001) and 40% lower for outpatient treatment (SCRT vs. LCRT: $11955 vs. $19641, p<0.001) compared to LCRT. SCRT was shown to be the dominant treatment option with fewer recurrences and fewer complications at a lower cost. CONCLUSION: SCRT was well-tolerated and achieved favorable short-term outcomes. In addition, SCRT showed significant reduction in the total cost of care and distinguished cost-effectiveness compared to LCRT.

Postoperative inpatient exercise facilitates recovery after laparoscopic surgery in colorectal cancer patients: a randomized controlled trial.

BACKGROUND: Early mobilization is an integral part of an enhanced recovery program after colorectal cancer surgery. The safety and efficacy of postoperative inpatient exercise are not well known. The primary objective was to determine the efficacy of a postoperative exercise program on postsurgical recovery of stage I-III colorectal cancer patients. METHODS: We randomly allocated participants to postoperative exercise or usual care (1:1 ratio). The postoperative exercise intervention consisted of 15 min of supervised exercise two times per day for the duration of their hospital stay. The primary outcome was the length of stay (LOS) at the tertiary care center. Secondary outcomes included patient-perceived readiness for hospital discharge, anthropometrics (e.g., muscle mass), and physical function (e.g., balance, strength). RESULTS: A total of 52 (83%) participants (mean [SD] age, 56.6 [8.9] years; 23 [44%] male) completed the trial. The median LOS was 6.0 days (interquartile range; IQR 5-7 days) in the exercise group and 6.5 days (IQR 6-7 days) in the usual-care group (P = 0.021). The exercise group met the targeted LOS 64% of the time, while 36% of the usual care group met the targeted LOS (colon cancer, 5 days; rectal cancer, 7 days). Participants in the exercise group felt greater readiness for discharge from the hospital than those in the usual care group (Adjusted group difference = 14.4; 95% CI, 6.2 to 22.6; P < 0.01). We observed a small but statistically significant increase in muscle mass in the exercise group compared to usual care (Adjusted group difference = 0.63 kg; 95% CI, 0.16 to 1.1; P = 0.03). CONCLUSION: Postsurgical inpatient exercise may promote faster recovery and discharge after curative-intent colorectal cancer surgery. TRIAL REGISTRATION: The study was registered at WHO International Clinical Trials Registry Platform (ICTRP; URL http://apps.who.int/trialsearch ); Trial number: KCT0003920 .

Palliative surgery as a bridge to systemic treatment for malignant bowel obstruction due to peritoneal metastases: A retrospective, case-control study.

BACKGROUND: High-quality data on palliative surgery in patients with malignant bowel obstruction (MBO) caused by peritoneal metastases (PM) are lacking. We aimed to determine the utility of palliative surgery for such patients. METHODS: We retrospectively analyzed patients considered for surgery for MBO, caused by PM, in our department from January 2019 to October 2020. None of them could tolerate a diet, despite conservative treatment. We investigated the clinical characteristics and perioperative outcomes and calculated overall survival (OS). Kaplan-Meier survival analysis was performed, with the log-rank test to evaluate differences in OS rates. Multivariate Cox regression was performed to determine prognostic factors. RESULTS: Sixty (67%) patients underwent surgery, whereas, 30 (33%) received the best supportive care (BSC) treatment. A better (p = 0.002) median OS was observed in patients undergoing surgery (3.9 months) than in those receiving BSC (2.6 months). Severe complications were observed in 12 (20%) patients, including 30-day mortality (7 patients). Forty-eight (80%) patients in the surgery group could tolerate a diet and the hospital stay (mean ± standard deviation) was 20.0 ± 23.1 days. Re-obstruction was observed in five (8.3%) patients after 78.6 ± 63.3 days. Patients in the postoperative chemotherapy group exhibited a better (p < 0.001) median OS (12.3 months) than did those in the no-postoperative chemotherapy group (3.5 months). Only postoperative chemotherapy (hazard ratio 0.264, 95% confidence interval 0.143-0.487, p < 0.001) was identified as an independent prognostic factor. CONCLUSIONS: Compared with BSC, surgery is associated with a better OS in patients with MBO due to PM. Surgery should be considered as a bridge to systemic treatment for such patients.

Association of neutrophil-to-lymphocyte ratio, radiotherapy fractionation/technique, and risk of development of distant metastasis among patients with locally advanced rectal cancer.

BACKGROUND: We investigated the prognostic impact of the neutrophil-to-lymphocyte ratio (NLR) in patients with locally advanced rectal cancer (LARC) and whether modifiable factors in radiotherapy (RT) influenced the NLR. METHODS: Data of 1386 patients who were treated with neoadjuvant RT and concurrent or sequential chemotherapy for LARC between 2006 and 2019 were evaluated. Most patients (97.8%) were treated with long-course RT (LCRT; 50-50.4 Gy in 25-28 fractions) using three-dimensional conformal radiotherapy (3D-CRT) (n = 851) or helical tomotherapy (n = 504), and 30 patients underwent short-course RT (SCRT; 25 Gy in 5 fractions, followed by XELOX administration for 6 weeks). Absolute neutrophil and lymphocyte counts were obtained at initial diagnosis, before and during the preoperative RT course, and after preoperative concurrent chemoradiotherapy. The primary endpoint was distant metastasis-free survival (DMFS). RESULTS: The median follow-up time was 61.3 (4.1-173.7) months; the 5-year DMFS was 80.1% and was significantly associated with the NLR after RT but not before. A post-RT NLR ≥ 4 independently correlated with worse DMFS (hazard ratio, 1.42; 95% confidence interval, 1.12-1.80), along with higher ypT and ypN stages. Post-RT NLR (≥ 4) more frequently increased following LCRT (vs. SCRT, odds ratio [OR] 2.77, p = 0.012) or helical tomotherapy (vs. 3D-CRT, OR 1.29, p < 0.001). CONCLUSIONS: Increased NLR after neoadjuvant RT is associated with increased distant metastasis risk and poor survival outcome in patients with LARC. Moreover, high NLR following RT is directly related to RT fractionation, delivery modality, and tumor characteristics. These results are hypothesis-generating only, and confirmatory studies are required.

Single-incision laparoscopic surgery compared to conventional laparoscopic surgery for appendiceal mucocele: a series of 116 patients.

BACKGROUND: Although the safety and feasibility of conventional laparoscopic surgery (CLS) for appendiceal mucocele (AM) has been reported, studies on single-incision laparoscopic surgery (SILS) for AM have not been reported. Here, we aimed to compare the perioperative and short-term outcomes between SILS and CLS for AM and to evaluate the oncological safety of SILS. METHODS: We retrospectively analyzed the medical records of patients, diagnosed based on computed tomography findings, who underwent laparoscopic surgery for AM between 2010 and 2018 at one institution. We excluded patients strongly suspected of having malignant lesions and those with preoperative appendiceal perforation. Patients were divided into two groups-CLS and SILS. Pathological outcomes and long-term results were investigated. The median follow-up period was 43.7 (range: 12.3-118.5) months. RESULTS: Ultimately, 116 patients (CLS = 68, SILS = 48) were enrolled. Patient demographic characteristics did not differ between the groups. The preoperative mucocele diameter was greater in the CLS than in the SILS group (3.2 ± 2.9 cm vs. 2.3 ± 1.4 cm, P = 0.029). More extensive surgery (right hemicolectomies and ileocecectomies) was performed in the CLS than in the SILS group (P = 0.014). Intraoperative perforation developed in only one patient per group. For appendectomies and cecectomies, the CLS group exhibited a longer operation time than the SILS group (63.3 ± 24.5 min vs. 52.4 ± 17.3 min, P = 0.014); the same was noted for length of postoperative hospital stay (2.9 ± 1.8 days vs. 1.7 ± 0.6 days, P < 0.001). The most common AM etiology was low-grade appendiceal mucinous neoplasm (71/116 [61.2%] patients); none of the patients exhibited mucinous cystadenocarcinoma. Among these 71 patients, there were 8 patients with microscopic appendiceal perforation or positive resection margins. No recurrence was detected. CONCLUSIONS: SILS for AM is feasible and safe perioperatively and in the short-term and yields favorable oncological outcomes. Despite the retrospective nature of the study, SILS may be suitable after careful selection of AM patients.

Long-term oncologic outcomes of single-incision laparoscopic surgery for colon cancer.

BACKGROUND: Studies find similar perioperative outcomes between single-incision laparoscopic surgery (SILS) and conventional laparoscopic surgery (CLS) for colon cancer. However, few have reported long-term outcomes of SILS versus CLS. We aimed to compare long-term postoperative and oncologic outcomes as well as perioperative outcomes between SILS and CLS for colon cancer. METHODS: A total of 641 consecutive patients who underwent laparoscopic surgery for colon cancer from July 2009 to September 2014 were eligible for the study. Data from 300 of these patients were used for analysis after propensity score-matching (n = 150 per group). Variables associated with short- and long-term outcomes were analyzed. RESULTS: The SILS group had a shorter mean total incision length, less postoperative pain, and a similar mean rate of incisional hernia (2.7% versus 3.3%) compared with the CLS group. The 7-year overall and disease-free survival rates were 92.7% versus 94% (p = 0.673) and 85.3% versus 84.7% (p = 0.688) in the SILS and CLS groups, respectively. CONCLUSIONS: Compared with CLS, SILS for colon cancer appeared to be safe in terms of perioperative and long-term postoperative and oncologic outcomes. The results suggested that SILS is a reasonable treatment option for colon cancer for a selected group of patients.

Three-dimensional anatomy of the Denonvilliers' fascia after micro-CT reconstruction.

An understanding of the anatomy of the Denonvilliers' fascia is essential for successful surgical outcomes for patients with rectal cancer in the mid- to lower regions, especially near the seminal vesicles and prostate in males. Whether the correct surgical plane during a total mesorectal excision should be anterior or posterior to the Denonvilliers' fascia is currently under debate. This study aimed to investigate the Denonvilliers' fascia using micro-computed tomography (micro-CT) to acquire three-dimensional images nondestructively for assessments of the relationship between the Denonvilliers' fascia, the mesorectal fascia, and neurovascular bundles to elucidate the correct anterior total mesorectal excision plane. Eight specimens were obtained bilaterally from four fresh human cadavers. Four specimens were stained with phosphotungstic acid to visualize the soft tissue, and micro-CT images were obtained; the other four specimens were stained with Masson's trichrome to visualize connective tissue. Micro-CT images corroborate that the Denonvilliers' fascia consists of a multilayered structure that separates the rectum from the seminal vesicles and the prostate. Specimens stained with Masson's trichrome showed that the urogenital neurovascular bundle located at the posterolateral corner of the prostate is separated from the mesorectum by the Denonvilliers' fascia. For the preservation of autonomic nerves necessary for urogenital function and optimal oncologic outcomes in patients with rectal cancer, a successful mesorectal excision requires a dissection plane posterior to the Denonvilliers' fascia.

Postoperative bleeding in essential thrombocytosis patients with colorectal cancer: Case report and literature review.

INTRODUCTION AND IMPORTANCE: Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by increased platelet count and a high risk of bleeding or thrombotic events due to platelet dysfunction. Patients with ET are treated according to their risk of complications with cytoreductive or anti-aggregant treatment. Neither guidelines for oncologic patients nor perioperative management of patients with ET have been determined. CASE PRESENTATION: A 41-year-old female patient with ET who had alternating constipation and diarrhea was referred after a screening colonoscopy diagnosing a locally advanced rectosigmoid junction colon adenocarcinoma with liver metastases. Systemic preoperative chemotherapy was indicated. The patient underwent laparoscopic low anterior resection plus volume-preserving right lobectomy of the liver. Postoperative bleeding of the internal iliac artery (IIA) associated with hematoma at the lower pelvic cavity was diagnosed and treated by interventional radiology; the patient was discharged without other complications 16 days after surgery. CLINICAL DISCUSSION: ET has been related to the development of hematologic complications or second non-hematologic malignancies. A systematic review was conducted to seek guidance for the management of such patients in the perioperative period. Special perioperative care must be taken, and complications management should avoid further hemorrhages or cloth formation. CONCLUSION: Under oncologic and hematological guidance, minimally invasive surgery and non-invasive management of complications are advised in the lack of published perioperative management guidelines of ET patients with colorectal cancer.

Intergranular Corrosion and Microstructural Evolution in a Newly Designed Al-6Mg Alloy.

In this work, the microstructure and corrosion behavior of a novel Al-6Mg alloy were investigated. The alloy was prepared by casting from pure Al and Mg+Al2Ca master alloy. The ingots were homogenized at 420 °C for 8 h, hot-extruded and cold-rolled with 20% reduction (CR20 alloy) and 50% reduction (CR50 alloy). The CR50 alloy exhibited a higher value of intergranular misorientation due to a higher cold rolling reduction ratio. The average grain sizes were 19 ± 7 µm and 17 ± 9 µm for the CR20 and CR50 alloys, respectively. An intergranular corrosion (IGC) behavior was investigated after sensitization by a nitric acid mass-loss test (ASTM G67). The mass losses of both the CR20 and CR50 alloys were similar at early periods of sensitization, however, the CR20 alloy became more susceptible to IGC as the sensitization time increased. Grain size and ß phase precipitation were two critical factors influencing the IGC behavior of this alloy system.

Outcomes of robotic partial excision of the levator ani muscle for locally advanced low rectal cancer invading the ipsilateral pelvic floor at the anorectal ring level.

PURPOSE: The purpose of this study is to evaluate partial excision of the levator ani muscle (PELM) enables preservation of anal sphincter function although levator ani muscle (LAM) was invaded. METHODS: Functional outcomes and oncologic outcomes of 23 consecutive patients who underwent robotic PELM for low rectal cancer at the anorectal ring level invading or abutting the ipsilateral LAM are analysed. RESULTS: Secured resection margins were achieved, especially for the circumferential resection margin. During a median follow-up of 44 months, the 3-year local recurrence rate was 14.4%. Among patients who underwent diverting ileostomy closure, mean Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores were 68.3 ± 11.9 and 10.7 ± 5.3, respectively, at 1 year after closure. CONCLUSION: PELM is a sphincter-preserving alternative to abdominoperineal resection (APR) or extralevator APR for low rectal cancer invading the ipsilateral LAM at the level of the anorectal ring.

Association of perioperative serum carcinoembryonic antigen level and recurrence in low-risk stage IIA colon cancer.

BACKGROUND: The purpose is to investigate prognosis according to serum CEA levels before and after surgery in patients with stage IIA colon cancer who do not show high-risk features. METHODS: Among the patients diagnosed with colon adenocarcinoma between April 2011 and December 2017, 462 patients were confirmed as low-risk stage IIA after surgery and enrolled. The ROC curve was used to determine cut-off values of pre- and postoperative CEA. Patients were classified into three groups using these new cut-off values. RESULTS: All recurrence occurred in 52 of 463 patients (11.2%). However, recurrence in group H was 15.9%, which was slightly higher than the other two groups (P = 0.04). Group L and M showed 10.5% and 12.8% overall survival, group H was higher at 21.0% (P = 0.005). Recurrence was the only risk factor in group H was significantly higher in group L (HR 2.008, 95% CI, 1.123-3.589, P = 0.019). Mortality was similar to recurrence (HR 1.975, 95% CI 1.091-3.523, P = 0.044). CONCLUSION: Among patients with low-risk stage IIA colon cancer, recurrence and mortality rates were higher when perioperative serum CEA levels were above a certain level. Therefore, high CEA level should be considered a high-risk feature and adjuvant chemotherapy should be performed.

Upfront chemotherapy and short-course radiotherapy with delayed surgery for locally advanced rectal cancer with synchronous liver metastases.

BACKGROUND: The optimal treatment of locally advanced rectal cancer with synchronous liver metastases remains controversial. In this study, we aimed to evaluate the safety, efficacy, and oncologic outcomes of upfront chemotherapy and short-course radiotherapy with delayed surgery in patients with locally advanced rectal cancer and synchronous liver metastases. METHODS: Forty-four patients who underwent upfront chemotherapy and short-course radiotherapy with delayed surgery for locally advanced rectal cancer (cT3/4, <2.0 mm from the mesorectal fascia) with synchronous liver metastases between January 2010 and June 2017 were reviewed retrospectively. Primary and metastatic liver lesions were resected with curative intent. Upfront chemotherapy and short-course radiotherapy were administered. Thereafter, restaging, surgery only, or additional chemotherapy followed by surgery was performed. RESULTS: At the time of initial diagnosis, 20 patients had <3 liver metastases; 24 patients had ≥3 liver metastases. Twenty-three patients had hemi-liver metastases; 21 patients had bilobar liver metastases. R0 resection of rectal lesions was achieved in 43 patients. Synchronous R0 resection of liver metastases was achieved in 41 patients. Postoperative complications (Clavien-Dindo Grade ≥ III) were noted in 5 patients. Grade 3/4 adverse events were observed in 26 patients. All adverse events were managed effectively with medication and supportive care. The 3-year overall survival and progression-free survival rates were 65.3% and 26.9%, respectively. CONCLUSION: Upfront chemotherapy and short-course radiotherapy with delayed surgery appear to be safe and effective in patients with locally advanced rectal cancer and synchronous liver metastases without substantially increasing treatment induced morbidity.

Can better surgical outcomes be obtained in the learning process of robotic rectal cancer surgery? A propensity score-matched comparison between learning phases.

BACKGROUND: Although studies of robotic rectal cancer surgery have demonstrated the effects of learning on operation time, comparisons have failed to demonstrate differences in clinicopathological outcomes between unadjusted learning phases. This study aimed to investigate the learning curve of robotic rectal cancer surgery for clinicopathological outcomes and compare surgical outcomes between adjusted learning phases. Study design We enrolled 506 consecutive patients with rectal adenocarcinoma who underwent robotic resection by a single surgeon between 2007 and 2018. Risk-adjusted cumulative sum (RA-CUSUM) for surgical failure was used to analyze the learning curve. Surgical failure was defined as the occurrence of any of the following: conversion to open surgery, severe complications (Clavien-Dindo grade ≥ 3a), insufficient number of harvested lymph nodes (LNs), or R1 resection. Comparisons between learning phases analyzed by RA-CUSUM were performed before and after propensity score matching. RESULTS: In RA-CUSUM analysis, the learning curve was divided into two learning phases: phase 1 (1st-177th cases, n = 177) and phase 2 (178th-506th cases, n = 329). Before matching, patients in phase 2 had deeper tumor invasion and higher rates of positive LNs on pretreatment images and preoperative chemoradiotherapy. After matching, phase 1 (n = 150) and phase 2 (n = 150) patients exhibited similar clinical characteristics. Phase 2 patients had lower rates of surgical failure overall and these components: conversion to open surgery, severe complications, and insufficient harvested LNs. CONCLUSIONS: For robotic rectal cancer surgery, surgical outcomes improved after the 177th case. Further studies by other robotic surgeons are required to validate our results.