Mesorectal pathologic assessment in two grades predicts accurately recurrence, positive circumferential margin, and correlates with survival

Role of Adjuvant Chemotherapy After Curative Resection in Stage II and III Rectal Cancer

INTRODUCTION

Patients with resected locally advanced rectal cancer (LARC) and an incomplete total mesorectal excision (TME) have worse oncologic outcomes. The associations between TME grade, adjuvant therapy receipt, and oncologic outcomes have not been well-studied. We aimed to determine the association between adjuvant chemotherapy and oncologic outcomes in patients who underwent neoadjuvant chemoradiation (CRT) or short-course radiotherapy (SCRT) followed by proctectomy and to evaluate this association stratified by TME grade.

MATERIALS AND METHODS

We analyzed a retrospective multi-institutional cohort of primary LARC patients diagnosed between 2010 and 2018 who received neoadjuvant CRT/SCRT followed by proctectomy. Complete TME was defined as complete mesorectal excision, and noncomplete TME was defined as near-complete or incomplete TME. We used adjusted Cox proportional hazards regression to test the association between adjuvant chemotherapy and mortality or locoregional recurrence (LRR) across groups.

RESULTS

We identified 746 eligible patients. On final pathology, 101 (13.5%) had noncomplete and 645 (86.5%) had complete TME. Rates of adjuvant chemotherapy receipt were similar between noncomplete and complete TME groups (70.3% and 69.5%, respectively). Mean follow-up interval was 35 mo. Adjuvant chemotherapy was associated with lower risk of mortality (HR 0.27, 95% CI 0.19-0.39, P < 0.001); the same association existed when stratifying patients by TME grade. For patients with a complete TME, adjuvant chemotherapy was associated with lower LRR (HR 0.08, 95% CI 0.01-0.56, P = 0.01). The LRR model for the noncomplete TME group did not converge due to few captured recurrences.

CONCLUSIONS

These data show an association between adjuvant chemotherapy and positive outcomes in LARC patients receiving neoadjuvant CRT/SCRT followed by proctectomy.

Meta-analysis of randomized clinical trials comparing robotic versus laparoscopic surgery for mid-low rectal cancers

INTRODUCTION

Robotic surgery (RS) is experiencing major development, particularly in the context of rectal cancer. The aim of this meta-analysis was to summarize data from the literature, focusing specifically on the safety and effectiveness of robotic surgery in mid-low rectal cancers, based on the hypothesis that that robotic surgery can find its most rational indication in this anatomical location.

METHOD

The meta-analysis was conducted according to the PRISMA 2000 recommendations, including all randomized trials that compared robotic surgery versus laparoscopic surgery (LS) that were found in the Medline-PICO, Cochrane Database, Scopus and Google databases. Data were extracted independently by two reviewers. The risk of bias was analyzed according to the Cochrane Handbook method and the certainty of the evidence according to the GRADE method. The analysis was carried out with R software Version 4.2-3 using the Package for Meta-Analysis "meta" version 6.5-0.

RESULTS

Eight randomized trials were included (with a total of 2342 patients), including four that focused specifically on mid-low rectal cancer (n=1,734 patients). No statistically significant difference was found for overall morbidity, intra-operative morbidity, anastomotic leakage, post-operative mortality, quality of mesorectal specimen, and resection margins. The main differences identified were a lower conversion rate for RS (RR=0.48 [0.24-0.95], p=0.04, I2=0%), and a longer operative time for RS (mean difference=39.11min [9.39-68.83], p<0.01, I2=96%). The other differences had no real clinical relevance, i.e., resumption of flatus passage (5hours earlier after RS), and lymph node dissection (one more lymph node for LS).

CONCLUSION

This meta-analysis does not confirm the initial hypothesis and does not show a statistically significant or clinically relevant benefit of RS compared to LS for mid-low rectal cancer.

Prognosis of Mesorectal Tumor Deposits in Patients with Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision

BACKGROUND

Tumor deposits (TDs) are associated with adverse prognostic factors and decreased survival in colon cancer. However, there is no information of their survival impact in rectal cancer with neoadjuvant chemoradiotherapy (n-CRT).

METHODS

Retrospective study in 223 patients with rectal cancer with n-CRT. A survival analysis of factors associated with decreased overall survival (OS) including TDs was performed.

RESULTS

From 223 patients, 131 (58.7%) were men, mean age 59.8 (± 13.06) years, and 42 (18.8%) of them revealed TDs. Survival analysis of TDs showed no association with mortality. Factors associated with decreased 5-year OS were the histologic grade (p = 0.42), perineural invasion (p = 0.001), and mesorectal quality (p = 0.067). Perineural invasion (HR = 2.335, 95% CI = 1.198-4.552) remained as independent factor in the multivariate analysis.

CONCLUSIONS

TDs were not associated with mortality in rectal cancer patients treated with n-CRT. Factors associated with decreased survival were inadequate mesorectal quality and perineural invasion.

Initial experience of Chinese surgical robot "Micro Hand S″ assisted versus open and laparoscopic total mesorectal excision for rectal cancer: Short-term outcomes in a single center

BACKGROUND

A Chinese surgical robot, Micro Hand S, was introduced for clinical use as a novel robotic platform. This study aimed to comprehensively compare the early experience of the Micro Hand S robot-assisted total mesorectal excision (TME) with conventional approaches.

METHODS

Between May 2017 and April 2018, 99 consecutive patients who underwent open, laparoscopic and Micro Hand S robot-assisted TME (O-/L-/RTME) for rectal cancer were included. Clinical and pathological outcomes were retrospectively analyzed. Surgical success as the primary endpoint was defined as the absence of (i) conversion, (ii) incomplete TME, (iii) involved circumferential and distal resection margins (CRM/DRM), (iv) severe complications.

RESULTS

The rate of surgical success was similar (89.7 vs. 86.4 vs. 84.6%, p = 0.851) in the three groups and the respective incidences were as follows: conversion (not applicable, 4.5 vs. 2.3%, p = 1.000), incomplete TME (6.9 vs. 6.8 vs. 3.8%, p = 0.980), involved CRM/DRM (0 vs. 2.3 vs. 3.8%, p = 0.592), severe complications (3.4 vs. 4.5 vs. 7.7%, p = 0.844). Compared with open and laparoscopic surgery, the robotic surgery was associated with longer operative time, less blood loss, earlier first flatus time and liquid intake time, and shorter length of hospital stay (p < 0.05).

CONCLUSIONS

The Micro Hand S assisted TME is safe and feasible, showing comparable outcomes than conventional approaches, with superiority in blood loss, recovery of bowel function, length of hospital stay, but with increased operative time.

Comparison of the operative outcomes and learning curves between laparoscopic and "Micro Hand S" robot-assisted total mesorectal excision for rectal cancer: a retrospective study

BACKGROUND

The Micro Hand S robot is a new surgical tool that has been applied to total mesorectal excision (TME) surgery for rectal cancer in our center. In this study, we compared the operative outcomes, functional outcomes and learning curves of the Micro Hand S robot-assisted TME (RTME) with laparoscopic TME (LTME).

METHODS

A total of 40 patients who underwent RTME and 65 who underwent LTME performed by a single surgeon between July 2015 and November 2018 were included in this retrospective study. Clinicopathologic characteristics, operative and functional outcomes, and learning curves were compared between the two groups. The learning curve was analyzed using the cumulative sum method and two stages (Phase 1, Phase 2) were identified and analyzed. All patients were followed up for at least 12 months.

RESULTS

The clinicopathologic characteristics of the two groups were similar. The learning curve was 17 cases for RTME and 34 cases for LTME. Compared with LTME, RTME was associated with less blood loss (148.2 vs. 195.0 ml, p = 0.022), and shorter length of hospital stay (9.5 vs. 12.2 days, p = 0.017), even during the learning period. With the accumulation of experience, the operative time decreased significantly from Phase 1 to Phase 2 (RTME, 360.6 vs. 323.5 min, p = 0.009; LTME, 338.1 vs. 301.9 min, p = 0.005), whereas other outcomes did not differ significantly.

CONCLUSIONS

Micro Hand S robot-assisted TME is safe and feasible even during the learning period, with outcomes comparable to laparoscopic surgery but superior in terms of blood loss, length of hospital stay, and learning curve. Trial registration Clinicaltrial.gov, NCT04836741, retrospectively registered on 5 April 2021.

Dual modal spectroscopic tissue scanner for colorectal cancer diagnosis

BACKGROUND

Margin status is an important prognostic factor for treating colorectal cancer. This study aimed to investigate the usefulness of a multimodal spectroscopic tissue scanner for real-time cancer diagnosis without tissue staining.

PATIENTS AND METHODS

Diffuse reflectance spectra (DRS) and fluorescence spectra (FS) of < 1-mm-sized paired cancer and normal mucosa tissue were acquired using custom-built spectroscopic tissue scanners. For FS, we analyzed wavelengths and intensities at peaks and highest intensities near (± 1.25 nm) the known fluorescence spectral peaks of collagen (380 nm), reduced nicotinamide adenine dinucleotide (NADH, 460 nm), and flavin adenine dinucleotide (FAD, 550 nm). For DRS, we performed a similar analysis near the peaks of strong absorbers, oxyhemoglobin (oxyHb; 414 nm, 540 nm, and 576 nm) and deoxyhemoglobin (deoxyHb; 432 nm and 556 nm). Logistic regression analysis for these parameters was performed in the testing set.

RESULTS

We acquired 17,735 spectra of cancer tissues and 9438 of normal tissues from 30 patients. Intensity peaks of representative normal spectra for FS and DRS were higher than those of representative cancer spectra. Logistic regression analysis showed wavelength and intensity at peaks, and the intensities of the peak wavelength of NADH, FAD, deoxyHb, and oxyHb had significant coefficients. The area under the receiver operating characteristic curve was 0.927. The scanner had 100%, 64.3%, and 85.3% sensitivity, specificity, and accuracy, respectively.

CONCLUSIONS

The spectroscopic tissue scanner has high sensitivity and accuracy and provides real-time intraoperative resection margin assessments and should be further investigated as an alternative to frozen section.

The relationship between mesorectal grading and oncological outcome in rectal adenocarcinoma

AIM

The prognostic association between mesorectal grading and oncological outcome in patients undergoing resection for rectal adenocarcinoma is controversial. The aim of this retrospective chart review was to determine the individual impact of mesorectal grading on rectal cancer outcomes.

METHOD

We compared oncological outcomes in patients with complete, near-complete and incomplete mesorectum who underwent rectal excision with curative intent from 2009 to 2014 for Stage cI-III rectal adenocarcinoma. We also assessed the independent association of mesorectal grading and oncological outcome using multivariate models including other relevant variables.

RESULTS

Out of 505 patients (339 men, median age of 60 years), 347 (69%) underwent a restorative procedure. There were 452 (89.5%), 33 (6.5%) and 20 (4%) patients with a complete, near-complete and incomplete mesorectum, respectively. Local recurrence was seen in 2.4% (n = 12) patients after a mean follow-up of 3.1 ± 1.7 years. Unadjusted 3-year Kaplan-Meier analysis by mesorectal grade showed decreased rates of overall, disease-free and cancer-specific survival and increased rates of overall and distant recurrence with a near-complete mesorectum, while local recurrence was increased in cases of an incomplete mesorectum (all P < 0.05). On multivariate analyses, a near-complete mesorectum was independently associated with decreased cancer-specific survival (hazard ratio 0.26, 95% CI 0.1-0.7; P = 0.007). There were no associations between mesorectal grading and overall survival, disease-free survival, overall recurrence or distant recurrence (all P > 0.05).

CONCLUSION

Mesorectal grading is independently associated with oncological outcome. It provides unique information for optimizing surgical quality in rectal cancer.

Overweight but not obesity is associated with decreased survival in rectal cancer

Aim of the study

To analyse the influence of overweight and obesity in disease-specific survival (DSS) in rectal cancers at stages I–III in a population with high prevalence of overweight/obesity.

Material and methods

The population (N = 304) consisted of Mexican patients with stage I–III rectal cancer during the period between 2009 and 2015. Patients were divided based on their body mass index (BMI) into normal weight 18–25 kg/m², overweight 25–29 kg/m², and obesity BMI > 30 kg/m² groups. Comparison of clinicopathologic features and survival analysis were performed.

Results

The median age was 58 years (interquartile range [IQR] 50–65) and the mean BMI was 26.03 ±4.06 kg/m². Patients in the obesity and overweight groups received a lower proportion of preoperative treatment and had a higher proportion of patients in stage II. Overweight patients had a lower baseline neutrophil/lymphocyte ratio and lower survival rate than patients with normal weight and with obesity (mean survival of 69.5 months vs. 81.15 months and 86.4 months, respectively). The estimated five-year DSS was 51% for the overweight group, 81% for the normal group, and 82% for the obesity group (p = 0.026).

Conclusions

Patients with stage I–III rectal cancer in the overweight group showed a lower DSS compared to groups with normal weight and with obesity, with the last two being similar.

Mismatch repair protein expression and intratumoral budding in rectal cancer are associated with an increased pathological complete response to preoperative chemoradiotherapy: A case-control study

AIM

To determine whether the association of rectal adenocarcinoma with a defective-mismatch repair system (dMMR) was associated with a pathological complete response (pCR) to preoperative chemoradiotherapy.

METHODS

A case-control study was designed with the aim of determining if patients with rectal adenocarcinoma with dMMR had an associated high pCR rate in response to neoadjuvant chemoradiotherapy (nCRT).

RESULTS

Seventy-two cases with pCR were compared against 144 controls without pCR. Across 216 cases, the mean age was 56.8 years, 140 (64.8%) were men, and 63 (29.2%) demonstrated the dMMR system. The pCR was associated with G1 tumors, dMMR, the absence of vascular invasion, and low tumor budding in the pretreatment biopsy. In a multivariant analysis, the factors associated with pCR were dMMR (OR: 2.61; 95%CI: 1.355-5.040, P = 0.004) and a low degree of tumor budding (OR: 2.52; 95%CI: 1.366-4.894, P = 0.025).

CONCLUSION

We found an independent association between dMMR and a low rate of tumor budding, with a higher rate of pCR, in the basal biopsies of patients with rectal carcinoma subjected to nCRT.

Pre-operative Neutrophils/Lymphocyte Ratio in Rectal Cancer Patients with Preoperative Chemoradiotherapy

BACKGROUND

Several studies have reported that an elevation in neutrophils/lymphocyte ratio (NLR) is correlated with poor survival in patients with colorectal cancer, but in rectal cancer (RC), it has been reported only in a few studies. It is necessary to separate colon cancer and rectal cancer to clarify the prognostic significance of NLR, especially in patients who received chemoradiotherapy.

METHODS

It is a comparative, observational retrospective study of a cohort of 175 patients. We grouped the patients into two based on their NLR (0-3 vs. > 3) to correlate with disease-specific survival (DSS) and pathologic complete response (pCR).

RESULTS

The average NLR was 2.65 + 1.32 (range 0.58-6.89), and 144 (82.3%) patients had an NLR of 0-3. The median follow-up was 33.53 months. There were no differences in pCR between the two groups. The 5-year DSS was 78.8%. NLR did not correlate with survival. Mesorectal quality, pT3-4 tumors, lymph node metastasis, lymphovascular invasion, perineural invasion, positive margins and recurrence were statistically significant predictors of increased mortality in univariate analysis. In multivariate analysis, only overall recurrence correlated with poor survival. The analysis of the association of NLR with outcomes with different cut points (2.0, 2.5, 4 and 5) did not show differences in DSS and pCR.

CONCLUSION

In our cohort, the NLR did not serve as a prognostic marker in patients with locally advanced rectal cancer and who received chemoradiotherapy and did not correlate with pCR as well.

GOLPH3 overexpression correlates with poor response to neoadjuvant therapy and prognosis in locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) combined with surgery is a standard therapy for locally advanced rectal cancer (LARC). The aim of this study was to assess the expression of GOLPH3 (Golgi phosphoprotein 3), a newly found oncogene, in LARC as well as its relationship with nCRT sensitivity and prognosis. We retrospectively analyzed 148 LARC cases receiving nCRT and total mesorectal excision (TME). Immunohistochemistry was used to assess GOLPH3 and mTOR (mammalian target of rapamycin) in tumor tissues. Then, the associations of GOLPH3 with pathological characteristics and prognosis of rectal cancer were assessed. The 148 cases included 77 with high GOLPH3 expression (52.03%), which was associated with tumor invasive depth and lymphatic metastasis. Cases with high GOLPH3 expression had 2.58 and 2.71 fold higher local relapse and distant metastasis rates compared with the low expression group. Correlation analyses showed that GOLPH3 was an independent indicator for judging tumor down-staging and postoperative TRG (tumor regression grade), indicating it could predict nCRT sensitivity. In addition, GOLPH3 expression was associated with mTOR levels. Multiple-factor analysis indicated that GOLPH3 was an independent prognosis indicator for 5 year-DFS (disease free survival) and OS (overall survival) in LARC. These results reveal that GOLPH3 is an independent predictive factor for nCRT sensitivity and prognosis in LARC, with a mechanism related to mTOR.

Extramural perineural invasion in pT3 and pT4 rectal adenocarcinoma as prognostic factor after preoperative chemoradiotherapy

Perineural invasion (PNI) is widely studied in malignant tumors, and its prognostic significance is well demonstrated in the head and neck and prostate carcinomas, but its significance in rectal cancer is controversial. Most studies have focused on evaluating mural PNI (mPNI); however, extramural PNI (ePNI) may influence the prognosis after rectal cancer resection. We evaluated the prognostic value of ePNI compared with mPNI and with non-PNI, in rectal resections after preoperative chemoradiotherapy in 148 patients with pT3 and pT4 rectal carcinomas. PNI was identified in 35 patients (23.6%), 60% of which were in the mPNI group. Factors associated with PNI were tumor invasion depth, lymph node metastasis, lymphovascular invasion, and venous invasion; patients with PNI were more likely to have positive resection margins (65.7% versus 11.6%). ePNI, compared with mPNI, was associated with female sex (64.3% versus 28.6%), positive surgical margins (42.8% versus 28.6%), recurrence (50% versus 28.6%), and death (92.9% versus 28.6%). The 5-year disease-specific survival rate was 78.1% for patients without PNI, compared with 63.7% for the mPNI group and 26.4% for the ePNI group (P<.001). On multivariate analysis, the independent adverse prognostic factors were ePNI (odds ratio [OR], 22.17; 95% confidence interval [CI], 17.03-24.58; P<.001), overall recurrence (OR, 9.19; CI, 6.11-10.63; P=.002), clinical stage IV (OR, 8.56; CI, 6.34-9.47; P=.003), and positive surgical margin (OR, 3.95; CI, 2.00-4.28; P=.047). In conclusion, we demonstrated the prognostic effect of ePNI for disease-specific survival in surgically resected pT3-pT4 rectal cancer patients with preoperative chemoradiotherapy.