Background
The descent of the small bowel into the pelvic dead space after extralevator abdominoperineal excision (ELAPE) presents a higher risk for postoperative complications. The aim of the ...present study was to evaluate the efficacy of pelvic peritoneum closure in preventing the small bowel from descending into the pelvic dead space and the potential consequences of this approach.
Methods
Patients with rectal cancer undergoing laparoscopic ELAPE from March 2014 to January 2019 were retrospectively investigated. Closure of the pelvic peritoneum (CPP) was routinely performed unless it was not feasible. All patients with pelvic peritoneum reconstruction were included in the CPP group, and patients without pelvic peritoneum reconstruction were included in the no-CPP group. The main outcomes included the incidences of the small bowel descending into the retro-urogenital space (space between the bladder/uterus and the sacrum on axial CT scans), perineal wound complications, perineal hernia, and small bowel obstruction (SBO).
Results
Of the 100 patients included, 79 received CPP, and 21 did not. Fewer patients with pelvic peritoneum closure had small bowels residing in the retro-urogenital space than patients without closure (17.7% vs 42.9%,
p
=0.014). The incidence of SBO was also lower in the CPP group (7.6% vs. 23.8%,
p
=0.034). Multivariable analysis showed that no-CPP (
p
=0.014) was an independent risk factor for the small bowel descending into the retro-urogenital space.
Conclusion
CPP may prevent the small bowel from descending into the retro-urogenital dead space in patients undergoing laparoscopic ELAPE without increasing the incidence of perineal wound complications. Prospective studies are warranted to confirm the efficacy of CPP in preventing SBO and perineal hernia.
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Groundwater hydrodynamics are significantly affected by the capillary effect when groundwater table approaches sand surface. A complex effective porosity was suggested to replace the specific yield ...to represent the capillary effect based on varieties of sand column experiments, and its estimation is based on the assumption that the response of time‐varying groundwater table is a simple harmonic motion. Nevertheless, groundwater hydrodynamics always consist of multiple harmonic components, which should be further examined. In this study, we first conducted laboratory sand column experiments with respect to different periodic oscillation conditions. Then, a fast Fourier transformation algorithm was applied to analyze the measured groundwater table, upon which the high order harmonic components under high frequency wave conditions was demonstrated. Subsequently, based on a perturbation approach, we presented a third order analytical solution of time‐varying groundwater table under a simple harmonic oscillation. The gradient descent method was applied to estimate the complex effective porosity by fitting the high order analytical solution to the experimental data. In addition, effects of various parameters, representing different driving head conditions and sediment properties, were testified through parametric studies, which demonstrates high order harmonic components should not be neglected under the conditions of large relative amplitude of driving head, short period oscillation, and the ratio of hydraulic conductivity to dynamic effective porosity being around 1 m/s, for example, in the scenarios of wave‐dominant swash zone. These new findings are of great importance to extend our understandings of the capillary effect on groundwater hydrodynamics.
Key Points
Sand column experiments were conducted to quantify the effects of high order components in groundwater table dynamics
High order analytical solution of the groundwater table under simple harmonic oscillation was presented based on a perturbation approach
The linear estimation approach is not suitable for estimating the complex effective porosity in the wave‐dominant swash zone
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Lateral pelvic lymph node metastasis is an important metastatic mode and a major cause of locoregional recurrence of mid-low rectal cancer. Recently, there is an East-West discrepancy in regard to ...the diagnosis, clinical significance, treatment and prognosis of lateral pelvic lymph node metastasis. In the West, lateral nodal involvement may represent systemic disease and preoperative chemoradiotherapy can sterilize clinically suspected lateral nodes. Thus, in many Western countries, the standard therapy for lower rectal cancer is total mesorectal excision with chemoradiotherapy, and pelvic sidewall dissection is rarely performed. In the East, and Japan in particular, however, there is a positive attitude in regard to lateral pelvic lymph node dissection (LPND). They consider that lateral pelvic lymph node metastasis is as regional metastasis, and the clinically suspected lateral nodes can not be removed by neoadjuvant chemoradiotherapy. The selective LPND after neoadjuvant chemoradiotherapy may be found to be
The effects of body mass index (BMI) in patients with rectal cancer have been poorly studied and are still controversial. In this study, we aimed to assess the effect of BMI on the long-term outcome ...in patients with rectal cancer after radical surgery.
Between April 2012 and December 2020, patients who received total mesorectal excision (TME) surgery were enrolled in the study. Patients were divided into four groups according to BMI level. Kaplan-Meier survival curves with log-rank tests were used to analyze overall survival (OS), Disease-free survival (DFS), local recurrence-free survival and distant metastasis-free survival. Univariate and multivariate analyses were performed to identify the risk factors associated with the long-term outcome. Nomograms were developed to predict the OS and DFS based on independent prognostic factors.
A total of 688 patients were included in this study. The median follow-up time was 69 months. The 5-year OS rates of the control, underweight, overweight and obese groups were 79.2%, 62.2%, 88.7% and 86.3%, respectively. The 5-year DFS rates were 74.8%, 58.2%, 80.5% and 81.4%, respectively. Overweight (HR 0.534; 95% CI 0.332-0.860, p = 0.010) was an independent protective factor for OS and DFS (HR 0.675; 95% CI 0.461-0.989, p = 0.044). Underweight was an independent risk factor for DFS (HR = 1.623; 95% CI 1.034-2.548; p = 0.035), and had a trend to be an independent risk factor for OS (HR 1.594; 95% 0.954-2.663; p = 0.075). Nomograms were established to predict the 2-year OS, 5-year OS, 2-year DFS and 5-year DFS with an area under curve (AUC) of 0.767, 0.712, 0.746 and 0.734, respectively.
For rectal cancer patients after radical surgery, overweight was an independent protective factor for OS and DFS. Underweight was an independent risk factor for DFS and had a trend to be an independent risk factor for OS. Nomograms incorporating BMI and other prognostic factors could be helpful to predict long-term outcome.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
The aim of this study was to identify the indications and oncological outcomes of selective lateral lymph node dissection (sLLND) in rectal cancer patients.
Methods
A retrospective study ...was conducted on consecutive patients with rectal cancer who had standard total mesorectal excision and sLLND at our institution. Clinicopathological characteristics and oncological outcomes were analyzed. We performed subgroup analysis and multivariate analysis based on patients with or without preoperative chemoradiotherapy to identify the related risk factors.
Results
A total of 77 consecutive patients with TME and sLLND were included. Twenty-two (28.6%) patients with pathological positive lateral lymph nodes metastasis (LLNM) were identified. Forty-seven (61%) patients accepted neoadjuvant chemoradiotherapy (nCRT). The pretreatment maximum short-axis diameters of LLN (≥ 8 mm) were the independent risk factors for LLNM among patients with LLN ≥ 5 mm. Lymph node metastasis were significantly higher in patients with pretreatment LLN ≥ 8 mm than in patients with LLN 5–8 mm (63% vs. 10%,
p
< 0.001). The receiver operating curve analysis suggested that the optimal cutoff value of LLN short-axis diameter for predicting LLNM was 8 mm. At a median follow-up of 42 months (range 6–140 months) 3 (3.9%) patients with lateral pelvic recurrence were observed. The 3-year cumulative overall survival in patients with LLNM and patients without LLNM was 76.7% and 89.8%, respectively (
p
= 0.01). The 3-year cumulative disease-free survival was 53.6% in patients with LLNM and 88.3% in patients without LLNM (
p
= 0.008).
Conclusion
Patients with LLNM had a worse prognosis. The pretreatment maximum short-axis diameter of LLN (≥ 8 mm) should be considered as an indication for sLLND.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
For patients with low- and intermediate-risk stage II/III rectal cancer, current studies have reached a consensus that preoperative radiotherapy may be dispensed with, and neoadjuvant chemotherapy ...(NCT) alone might achieve an accepted local control. Our previous phase II study has evidenced that the morphological response of NCT could be better judged at a relatively early stage. Low- and intermediate-risk stage II/III rectal cancer patients could achieve a high rate of tumor shrinkage and downgrade after only 4 cycles of NCT and obvious tumor morphological changes could be observed after 2 cycles of NCT. However, there is still a lack of more detailed stratification and evidence for pathological criteria. The aim of the present study (comparison of the pathological response to 2 or 4 cycles of neoadjuvant CAPOX in II/III rectal cancer patients with low/intermediate risks, COPEC trial) is to determine the pathological tumor regression grade (pTRG) rate of 2 or 4 cycles of NCT in low- and intermediate-risk stage II/III rectal cancer and verify the feasibility of early identification of chemotherapy-insensitive population.
This is a multicenter, prospective, non-inferior, randomized controlled trial (RCT) initiated by West China Hospital of Sichuan University and designed to be conducted in fourteen hospitals around China. Eligible patients will be centrally randomized into 2 or 4 cycles of CAPOX in a 1:1 ratio using the central automated randomization system offered by the O-trial online system ( https://plus.o-trial.com/ ) and accept total mesorectal excision after 2 or 4 cycles of CAPOX (oxaliplatin 130 mg/m
, once daily on day 1, every 21 days and capecitabine 1000 mg/m
, twice daily on days 1 to 14, every 21 days). The primary endpoint is the proportion of patients with pathological no-tumor regression (pTRG 3), which is determined postoperatively by each sub-center and verified by the primary center.
COPEC trial is designed to verify that the preoperative CAPOX chemotherapy for low- and intermediate-risk stage II/III rectal cancer could achieve a good response judgment after 2 cycles and obtain the tumor pathological response rate after 2 cycles of CAPOX. We hope the COPEC trial could help in establishing a consensus standard of low- and intermediate-risk rectal cancer and the early identification of stage II/III rectal patients with low- and intermediate-risk who are poorly responding to NCT.
Clinicaltrial.gov NCT04922853. Registered on June 4, 2021.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•The melting point of bulk Fe (1815.8K), which is strikingly close to the experimental data (1811K), has been predicted in this work.•Two different inner structures including fivefold twinning and ...lamellar structure have been found.•Surface premelting and internal defect have been observed visually during the melting process of fivefold and lamellar structure.
Continuous melting and cooling of isolated fcc-Fe nanoparticles with 59–9577 atoms are studied by Molecular Dynamics (MD) simulation with Sutton–Chen potential. An energy minimization process was employed to obtain the stable solid structure for simulation of melting. The energy-minimized nanoparticles show lower potential energy and radius compared with the counterparts without energy minimizing. The size dependence of melting point shows perfect linear variation with N−1/3 for particles above a limit of 113 atoms. The bulk melting temperature of 1833.3K, which is close to the experimental data (1811K for bcc and 1800.8K for fcc), has been predicted by a linear relationship. Two different inner structures, including five-fold twinning and lamellar structures, have been found to be the initial stable configurations prior to melting, and both surface premelting and internal defects were verified as the origins for melting behavior.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
IntroductionNeoadjuvant chemotherapy (NAC) has been demonstrated effective in several tumours, but its benefit has not yet been elucidated in colorectal cancer, especially locally advanced colorectal ...cancer (LACRC).Methods and analysisThis is a single-arm, open-label, prospective phase II exploratory clinical trial. Patients with LACRC will receive four cycles of NAC with 5-fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI), followed by operation and then adjuvant chemotherapy with capecitabine and oxaliplatin for two to five cycles or single-agent capecitabine for five cycles, or observation. The primary endpoint is the rate of tumour regression grade (TRG) 0–2 in the resected tumour tissue, which is evaluated by experienced pathologists according to the Ryan R TRG grading system. Secondary endpoints include objective response rate, pathologic complete response, microscopically complete resection rate, progression-free survival, distant metastasis-free survival, overall survival, toxicity and compliance to study treatment, molecular markers, quality of life to study treatment and the number of patients with 30-day postoperative mortality. The objective of this study is to analyse the efficacy and safety of FOLFOXIRI as the NAC regimen in patients with LACRC and to identify a promising treatment strategy in this setting.Ethics and disseminationWritten informed consent will be required from and provided by all patients enrolled. The study protocol has been approved by the independent ethics committee of West China Hospital, Sichuan University (approval number: 2021403). This study will demonstrate the potential benefit of NAC with the FOLFOXIRI regimen. Results will be shared with policymakers and the academic community to promote the clinical management of colon cancer.Trial registration numberNCT05018182.
Purpose
As a kind of secondary tumor of the ovary, ovarian metastasis from colorectal cancer (OMCRC) happens rarely. Prognostic factors of OMCRC are still undetermined. This study was conducted to ...analyze clinical characteristics and prognostic factors of OMCRC patients.
Methods
Data of patients with OMCRC were collected retrospectively from four large-capacity hospitals in China. Kaplan-Meier method was applied to estimate disease-specific overall survival (OS), and multivariate Cox regression analysis was used to identify prognostic factors. A novel nomogram was developed to estimate individual survival probability, whose performance was internally validated using concordance index (C-index) and calibration curve.
Results
Totally, 162 cases were eligible, with a median age at diagnosis of 49 years old. The median size of ovarian metastases was 9.0 cm (95% CI: 8.5–10.4 cm). 93.8% of patients received surgery of ovarian metastases. Median time from CRC diagnosis to metachronous ovarian metastasis was 13.0 months (95% CI: 13.5–17.7 months). Median OS after ovarian metastasis diagnosis was 26.0 months (95% CI: 22.3–29.7 months). Integrating univariate and multivariate analyses, eight factors (including age, menopausal status, primary tumor location, N stage of primary tumor, surgery of primary tumor, differentiation grade, bilateral metastasis, and systemic chemotherapy) were used to develop a novel nomogram, with a C-index of 0.65 (95% CI: 0.595–0.705). Calibration curves indicated relatively good agreement between predicted and actual survival.
Conclusions
This nomogram could be a promising tool to help clinicians to estimate individual survival outcome of patients with OMCRC. Further study is warranted to validate the practicality of this model.
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
