Current perioperative care in patients undergoing a beyond total mesorectal excision procedure for rectal cancer: What are the differences with the colorectal enhanced recovery after surgery protocol?

AIM: Patients requiring a beyond total mesorectal excision (bTME) procedure for locally advanced rectal cancer (LARC) and locally recurrent rectal cancer (LRRC) will probably benefit from enhanced recovery after surgery (ERAS) protocols. However, implementation of ERAS protocols in such groups of patients is considered challenging. The aims of this study were to evaluate ERAS-related outcomes of patients with LARC or LRRC undergoing bTME and to investigate the possibility of designing a tailored ERAS protocol. METHOD: This study was divided into four phases. Phase one consisted of a literature study to compare functional recovery and postoperative outcomes in patients undergoing bTME. In phase two, outcomes on ERAS care elements in bTME were retrospectively evaluated. In phase three, differences in ERAS-related outcomes and compliance of the colorectal ERAS protocol in patients who had undergone bTME were studied. In phase four, multidisciplinary team meetings were held to develop an ERAS protocol for bTME patients. RESULTS: Seven studies reported on ERAS-related outcomes in patients undergoing bTME. Median length of hospital stay was 9-19 days, median stay in the intensive care unit was 2-4 days and 30-day postoperative major complication rates were 22.6%-61.3%. Seventy-five bTME patients were included for retrospective analysis. In these patients, length of stay was 9.0 days and major postoperative complications were observed in 40.0%. The overall ERAS compliance was 44.4%. Compared with the colorectal ERAS protocol, the largest differences in management were observed in the use of epidural anaesthesia, the postoperative use of urethral catheters, oral intake and mobilization. CONCLUSION: Patients undergoing bTME for LARC or LRRC are substantially different from patients treated with the colorectal ERAS protocol, regarding ERAS-related outcomes. A tailored, multimodal ERAS protocol with specific modifications was developed by an expert multidisciplinary team for patients undergoing bTME for LARC or LRRC.

Modified FOLFOX6 with Cetuximab versus with Radiotherapy in Neoadjuvant Treatment of Locally Advanced Rectal Cancer: A Single-Center, Prospective, Randomized Controlled Trial.

In this trial, the feasibility and efficacy of neoadjuvant chemotherapy with targeted agents in the treatment of patients with locally advanced rectal cancer were evaluated. In this single-center, prospective, randomized controlled trial, we randomly assigned (1 : 1) patients with locally advanced rectal cancer with wild-type RAS/BRAF gene to two groups: 5 cycles of modified leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin combination regimen (modified FOLFOX6, mFOLFOX6) concurrent with 25 times radiotherapy or 5 cycles of mFOLFOX6 plus cetuximab, all with subsequent total mesorectal excision (TME) resection and adjuvant chemotherapy. We performed a random assignment by a computer-generated random number sequence. The primary end point was the R0 resection rate. The secondary end points were rates of pathologic complete response, downstaging, adverse events, postoperative complications, preventive enterostomy and low anterior resection syndrome. From January 6, 2020 to October 28, 2022, 80 patients were assigned and evaluated. In the mFOLFOX6-RT and mFOLFOX6-Cet groups, the rate of R0 resection was 96.7 and 96.9% (p = 1.000); the rate of pathological complete response (pCR) was 23.3 and 21.9% (p = 0.891); and the rate of downstaging (ypStage 0 to 1) was 53.3 and 53.1% (p = 1.000), respectively. No statistical differences between the two groups were observed in the incidence of adverse events and postoperative complications. Additionally, lower rates of preventive enterostomy and low anterior resection syndrome were shown in the mFOLFOX6-Cet group compared to the mFOLFOX6-RT group. The neoadjuvant treatment strategy of mFOLFOX6 with cetuximab is feasible and promising for patients with locally advanced rectal cancer, even superior to mFOLFOX6 with radiotherapy.

Age-related differences in progression patterns, follow-up strategies, and postoperative outcomes in locally advanced rectal cancer: insights from a large-scale validated study.

Background: Locally advanced rectal cancer (LARC) presents significant treatment challenges, particularly as patient age may influence disease progression and treatment response. Understanding the differences in progression patterns and treatment outcomes between older patient (OP) and non-older patient (NOP) is essential for tailoring effective management strategies. Objectives: We aimed to explore the differences of progression pattern, postoperative treatment, and survival outcome between OP and NOP groups in LARC. Design/Methods: The random survival forest model was used to determine the probability of time-to-event occurrence every 3 months. Patients in the NOP and OP group were both categorized into three risk groups based on progression-free survival nomogram scores. We employed inverse probability of treatment weighting (IPTW) analysis and the Surveillance, Epidemiology, and End Results (SEER) database to verify our findings. Results: Our results revealed that Groups 1, 2, and 3 experienced peaks in progression within the first 24 months in NOP group. As for OP group, Group 4 reached a progression peak at the 18th month, Group 5 at the 12th month, and Group 6 at the 9th month. In NOP group, high-risk patients who underwent postoperative chemotherapy had significantly improved overall survival compared to those who did not. Additionally, postoperative chemotherapy did not significantly improve prognosis for patients in low-, moderate-, or high-risk groups of OP group. Finally, the validation results of IPTW analysis and SEER database showed compliance with our findings. Conclusion: For NOP group, we recommended close follow-up during the first 2 years. As for OP group, it was suggested to conduct close follow-up at the 18th, 12th, and 9th month for low-, moderate-, and high-risk groups, respectively. Furthermore, postoperative chemotherapy can provide survival benefits for patients in high-risk group of NOP group. However, OP group patients should be informed that the potential benefits of postoperative chemotherapy may be minimal.

Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer: Insights from the Western Australian Context.

BACKGROUND: Recent studies have associated total neoadjuvant therapy (TNT) with better treatment adherence, decreased toxicity, improved complete clinical response and anal sphincter preservation rates in patients with locally advanced rectal cancer (LARC). However, real-world experience with TNT in the management of LARC remains limited. AIM: This study aimed to evaluate the efficacy and safety outcomes of TNT for LARC in Western Australia. METHODS: Patients with LARC (cT2-4 and/or cN1-2) who underwent induction chemotherapy followed by neoadjuvant chemoradiotherapy or neoadjuvant chemoradiotherapy followed by consolidation chemotherapy, followed by surgery were recruited from two hospitals in Western Australia. Efficacy outcomes assessed included clinical response (complete, partial, no response), and pathologic complete response (pCR) rate, R0 resection rate, and R1 resection rate were evaluated. Those patients who achieved clinical complete response following TNT were given the option of active surveillance. The safety and tolerability of TNT were assessed. RESULTS: 32 patients with LARC were treated with TNT. In total, 17 patients (53%) received chemoradiotherapy followed by consolidation chemotherapy and 15 patients (47%) received induction chemotherapy followed by chemoradiotherapy. Nine (28%) of the patients with LARC treated with TNT had a complete clinical response, twenty-one (66%) patients had a partial clinical response, and two (6%) patients had no response to TNT. Of the 32 patients, 27 (84%) underwent surgery. There was a 100% R0 resection rate. The pCR rate was 15%. pCR, clinical response, and the R0 resection rate were similar between the two TNT regimens. TNT was well tolerated, with the majority of patients (88%) completing the chemotherapy course with grade 1 and 2 adverse effects. CONCLUSIONS: In conclusion, TNT emerges as a promising approach for the management of LARC. However, further research is warranted to refine the optimal TNT protocols, determine its long-term outcomes, and identify patient populations who would benefit the most from this innovative therapeutic strategy.

Impact of Sarcopenia on Treatment Outcomes and Toxicity in Locally Advanced Rectal Cancer.

Background and Objectives: Sarcopenia, a condition characterized by muscle mass loss, is prevalent in up to 68% of rectal cancer patients and has been described as a negative prognostic factor, impacting overall survival and tumor response. While there are extensive data on rectal cancer globally, only a handful of studies have evaluated the role of sarcopenia in locally advanced rectal cancer (LARC). Our study aimed to investigate the relationship between sarcopenia, overall response rate, and toxicity in patients who underwent total neoadjuvant treatment (TNT) for LARC. Materials and Methods: We performed a retrospective study of patients with rectal cancer treated with TNT and surgery with curative intent between 2021 and 2023 at Prof. Dr. Ion Chiricuta Institute of Oncology, Cluj-Napoca. Sarcopenia was assessed on MRI images by measuring the psoas muscle area (PMA) at the level of the L4 vertebra before and after neoadjuvant therapy. The primary endpoints were the overall complete response rate (oCR) and acute toxicity. Results: This study included 50 patients with LARC. The oCR rate was 18% and was significantly associated with post-treatment sarcopenia (OR 0.08, p = 0.043). Patients who did not achieve a clinical or pathologic complete response had, on average, an 8% muscle loss during neoadjuvant therapy (p = 0.022). Cystitis and thrombocytopenia were significantly associated with post-treatment sarcopenia (p = 0.05 and p = 0.049). Conclusions: Sarcopenia and loss of psoas muscle during neoadjuvant therapy were negatively associated with tumor response in locally advanced rectal cancer. Thrombocytopenia and cystitis are more frequent in sarcopenic than non-sarcopenic patients undergoing neoadjuvant chemoradiation for rectal cancer.

Curative immune checkpoint inhibitors therapy in patients with mismatch repair-deficient locally advanced rectal cancer: a real-world observational study.

BACKGROUND: Sustained clinical complete remissions were reported in all of 23 mismatch repair deficient/microsatellite instable (dMMR/MSI) locally advanced rectal cancer (LARC) patients treated with dostarlimab alone in a recent phase II study. These results led to off-label use of dostarlimab or other immune checkpoint inhibitors (ICIs) in dMMR/MSI-LARC even before regulatory approval. The present study [STAR(t)-IT-REDUCE] describes the outcome of dMMR/MSI-LARC patients treated with ICI in Italy. MATERIALS AND METHODS: Investigator-initiated, observational, retrospective-cohort, multicentric study of ICI treatment in dMMR/MSI-LARC. Patients were eligible if treated with ≥1 ICI dose from July 2022 to December 2023 (date of approval of dostarlimab for this indication in Italy). RESULTS: Seventeen dMMR/MSI-LARC patients (13 of 17 treatment-naïve) were eligible. Fourteen patients completed 6 months of treatment, two discontinued after four doses and one after five doses because of immune-related pneumonia, social constraints, or non-oncological bowel obstruction, respectively. Overall, 16 of 17 assessable patients [94.1%; 95% confidence interval (CI) 69.24% to 99.69%, 'ITT analysis'] achieved complete clinical response (cCR). Ten of 11 treatment-naïve patients completing 6 months of treatment had cCR (90.9%; 95% CI 57.12% to 99.52%, 'per-protocol analysis'). One patient with near-CR underwent rectal surgery and minimal residual intramucosal tumor was found. With a median follow-up of 9.5 months, no local relapse occurred. One patient developed unconfirmed lung metastases. Two grade 3 and no grade 4 adverse events were reported. CONCLUSION: The present STAR(t)-IT-REDUCE study documents the immunoablative and curative activity of ICI monotherapy in dMMR/MSI-LARC. Toxicity and compliance issues inherent to real-world practice are limited and do not affect achievement of initial complete tumor response but may limit response duration.

First in human intraarterial delivery of tislelizumab for the treatment of pMMR locally advanced rectal cancer: A single-arm, open label, phase II clinical trial.

BACKGROUND: Intravenous immune checkpoint inhibitors (ICIs) have shown efficacy in treating locally advanced rectal cancer (LARC), but concerns about systemic toxicity persist. This study developed a unique approach termed chemo-immuno-embolization with transcatheter rectal arterial intervention (CIETAI), aiming to enhance the anti-tumor response while minimizing systemic toxicity. METHOD: This is a prospective, single-arm, phase II clinical trial conducted in Daping hospital. Patients with previously untreated stage II/III LARC underwent preoperative CIETAI combined with PD-1 inhibitor tislelizumab plus oxaliplatin, followed by standard concomitant chemoradiotherapy (capecitabine and 50.4 Gy radiation). Intravenous tislelizumab was administered for an additional two cycles. RESULTS: Between January 2023 and December 2023, a total of 38 patients were enrolled. As the primary endpoint, 17 (44.74 %) patients achieved pathological complete response (TRG0), with a major pathologic response (MPR) rate of 65.79 %. The anal preservation rate was 84.21 % (32/38), and importantly, 15 of 21 patients with low rectal cancer achieved organ preservation with functional maintenance. Eight patients experienced grade 3-4 adverse events (AEs). All immune-related AEs were grade 1-2, with the most common being endocrine toxicity (5/6, 83.33 %). No grade 5 AEs occurred. CONCLUSION: This study provides preliminary evidence supporting the safety and efficacy of intraarterial tislelizumab delivery in the neoadjuvant setting for LARC. These promising results encourage further exploration in larger cohorts to validate the clinical impact of this novel CIETAI strategy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05957016.

Tailoring treatment for locally advanced rectal cancer.

The management of locally advanced rectal cancer (LARC) requires personalized treatment to improve outcomes and maintain quality of life. This narrative review examines the recent developments in management, focusing on non-operative management, radiotherapy choices or omission, chemotherapy sequencing, and the role of immunotherapy and brachytherapy boost. Non-operative management can be an option for select patients, and the use of long-course chemoradiation (LCCRT) with consolidation chemotherapy or brachytherapy boost has been shown to enhance rectal preservation rates. For patients requiring surgery, the choice between LCCRT and SCRT depends on the risk of local recurrence and patient preferences. MSI-high LARC patients benefit significantly from single-agent immunotherapy, and early clinical trials show promising results for the application of immunotherapy in MSS tumors. By stratifying patients based on individual and tumor risk factors, clinicians can tailor treatment plans to improve oncologic outcomes and quality of life for patients with LARC.

Neoadjuvant chemoradiotherapy in combination with deep regional hyperthermia followed by surgery for rectal cancer: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Combining chemoradiotherapy (CRT) with deep regional hyperthermia (HT) shows promise for enhancing clinical outcomes in selected rectal cancer patients. This study aimed to integrate the evidence and evaluate the efficacy of this combined treatment approach. MATERIALS AND METHODS: A systematic search of the PubMed, Scopus, and Mendeley databases was performed. This review was conducted according to the PRISMA guidelines. The quality of studies was evaluated using the Newcastle-Ottawa scale (NOS). Random-effects meta-analyses (DerSimonian and Laird) were performed. The primary outcome was pathological complete response (pCR), and secondary endpoints were overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and toxicity. RESULTS: In total, 12 studies were included, mostly of moderate quality. Patients with locally advanced rectal cancer (LARC; n = 760) and locally recurrent rectal cancer (LRRC; n = 22) were eligible. The pooled pCR rate was 19% (95% confidence interval [CI]: 16-22%) among all 782 patients and 19% (95%CI:16-23%) among 760 LARC patients. Due to significant study heterogeneity, survival outcomes were pooled by excluding LRRC patients. The pooled 5­year OS rate among 433 LARC patients was 87% (95%CI: 83-90%). The pooled 5­year DFS and LRFS in LARC patients were 75% (95%CI: 70-80%) and 95% (95%CI: 92-97%), respectively. There was a lack of consistent reporting of HT treatment parameters and toxicity symptoms among the studies. CONCLUSION: The collective clinical evidence showed that neoadjuvant CRT combined with HT in rectal cancer patients is feasible, with a 19% pCR rate and excellent survival outcomes in long term follow-up.

Outcomes and failure patterns after chemoradiotherapy for locally advanced rectal cancer with positive lateral pelvic lymph nodes: a propensity score-matched analysis.

PURPOSE: This study aimed to use propensity score matching (PSM) to explore the long-term outcomes and failure patterns in locally advanced rectal cancer (LARC) patients with positive versus negative lateral pelvic lymph node (LPLN). MATERIALS AND METHODS: Patients with LARC were retrospectively divided into LPLN-positive and LPLN-negative groups. Clinical characteristics were compared between the groups using the chi-square test. PSM was applied to balance these differences. Progression-free survival (PFS) and overall survival (OS), and local-regional recurrence (LRR) and distant metastasis (DM) rates were compared between the groups using the Kaplan-Meier method and log-rank tests. RESULTS: A total of 651 LARC patients were included, 160 (24.6%) of whom had positive LPLN and 491 (75.4%) had negative LPLN. Before PSM, the LPLN-positive group had higher rates of lower location (53.1% vs. 43.0%, P = 0.025), T4 stage (37.5% vs. 23.2%, P = 0.002), mesorectal fascia (MRF)-positive (53.9% vs. 35.4%, P < 0.001) and extramural venous invasion (EMVI)-positive (51.2% vs. 27.2%, P < 0.001) disease than the LPLN-negative group. After PSM, there were 114 patients for each group along with the balanced clinical factors, and both groups had comparable surgery, pathologic complete response (pCR), and ypN stage rates. The median follow-up was 45.9 months, 3-year OS (88.3% vs. 92.1%, P = 0.276) and LRR (5.7% vs. 2.8%, P = 0.172) rates were comparable between LPLN-positive and LPLN-negative groups. Meanwhile, despite no statistical difference, 3-year PFS (78.8% vs. 85.9%, P = 0.065) and DM (20.4% vs. 13.3%, P = 0.061) rates slightly differed between the groups. 45 patients were diagnosed with DM, 11 (39.3%) LPLN-positive and 3 (17.6%) LPLN-negative patients were diagnosed with oligometastases (P = 0.109). CONCLUSIONS: Our study indicates that for LPLN-positive patients, there is a tendency of worse PFS and DM than LPLN-negative patients, and for this group patients, large samples are needed to further confirm our conclusion.

Node-sparing modified short-course Radiotherapy Combined with CAPOX and Tislelizumab for locally Advanced MSS of Middle and low rectal Cancer (mRCAT): an open-label, single-arm, prospective, multicentre clinical trial.

BACKGROUND: Neoadjuvant chemoradiotherapy followed by total mesorectal excision is a standard treatment for locally advanced rectal cancer. Mismatch repair-deficient locally advanced rectal cancer (LARC) was highly sensitive to PD-1 blockade. However, most rectal cancers are microsatellite stable (MSS) or mismatch repair-proficient (pMMR) subtypes for which PD-1 blockade is ineffective. Radiation can trigger the activation of CD8 + T cells, further enhancing the responses of MSS/pMMR rectal cancer to PD-1 blockade. Radioimmunotherapy offers a promising therapeutic modality for rectal cancer. Progenitor T exhausted cells are abundant in tumour-draining lymph nodes and play an important role in immunotherapy. Conventional irradiation fields include the mesorectum and regional lymph nodes, which might cause considerable damage to T lymphocytes and radiation-induced fibrosis, ultimately leading to a poor response to immunotherapy and rectal fibrosis. This study investigated whether node-sparing modified short-course irradiation combined with chemotherapy and PD-1 blockade could be effective in patients with MSS/ pMMR LARC. METHODS: This was a open-label, single-arm, multicentre, prospective phase II trial. 32 LARC patients with MSS/pMMR will receive node-sparing modified short-course radiotherapy (the irradiated planned target volume only included the primary tumour bed but not the tumour-draining lymph nodes, 25 Gy/5f, 5 Gy/f) followed by CAPOX and tislelizumab. CAPOX and tislelizumab will be started two days after the completion of radiotherapy: oxaliplatin 130 mg/m2 intravenous infusion, day 1; capecitabine 1000 mg/m2 oral administration, days 1-14; and tislelizumab 200 mg, intravenous infusion, day 1. There will be four 21-day cycles. TME will be performed at weeks 14-15. We will collect blood, tumour, and lymphoid specimens; perform flow cytometry and in situ multiplexed immunofluorescence detection; and analyse the changes in various lymphocyte subsets. The primary endpoint is the rate of pathological complete response. The organ preservation rate, tumour regression grade, local recurrence rate, disease-free survival, overall survival, adverse effects, and quality of life will also be analysed. DISCUSSION: In our research, node-sparing modified radiotherapy combined with immunotherapy probably increased the responsiveness of immunotherapy for MSS/pMMR rectal cancer patients, reduced the occurrence of postoperative rectal fibrosis, and improved survival and quality of life. This is the first clinical trial to utilize a node-sparing radiation strategy combined with chemotherapy and PD-1 blockade in the neoadjuvant treatment of rectal cancer, which may result in a breakthrough in the treatment of MSS/pMMR rectal cancer. TRIAL REGISTRATION: This study was registered at www. CLINICALTRIALS: gov . TRIAL REGISTRATION NUMBER: NCT05972655. Date of registration: 31 July 2023.

CapeOX as neoadjuvant chemotherapy for locally advanced rectal cancer: might less be more?

BACKGROUND: Locally advanced rectal cancer (LARC) poses unique challenges in treatment, with current neoadjuvant chemoradiotherapy (NA-CRT) showing limitations. The CapeOX regimen emerges as a potential less aggressive neoadjuvant chemotherapy (NAC) for LARC. METHODS: We conducted a retrospective study involving treatment-naïve patients with LARC from March 2014 to March 2021 who received 2-4 cycles of CapeOX NAC followed by radical surgery. Treatment response was evaluated using tumor regression grade (TRG), MRI-based TRG (MRI-TRG), and Neoadjuvant Rectal (NAR) score. RESULTS: 94.7% of patients experienced symptom improvement and 96.4% achieved sphincter-preserving surgery. Post-NAC showed significant tumor regression and MRI confirmed a tumor length reduction (P < 0.001). Clinical and pathological staging discrepancies post-NAC suggest broader therapeutic advantages. 5-year overall and disease-free survival rates were 78.4% and 73.4%. NAR scores provided better prognostic accuracy than MRI-TRG. CONCLUSION: CapeOX NAC presents notable benefits for LARC patients and its clinical significance may be underestimated. The NAR score demonstrates superior prognostic value over MRI-TRG.

Combination of intravoxel incoherent motion histogram parameters and clinical characteristics for predicting response to neoadjuvant chemoradiation in patients with locally advanced rectal cancer.

OBJECTIVE: To explore the value of histogram parameters derived from intravoxel incoherent motion (IVIM) for predicting response to neoadjuvant chemoradiation (nCRT) in patients with locally advanced rectal cancer (LARC). METHODS: A total of 112 patients diagnosed with LARC who underwent IVIM-DWI prior to nCRT were enrolled in this study. The true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and microvascular volume fraction (f) calculated from IVIM were recorded along with the histogram parameters. The patients were classified into the pathological complete response (pCR) group and the non-pCR group according to the tumor regression grade (TRG) system. Additionally, the patients were divided into low T stage (yp T0-2) and high T stage (ypT3-4) according to the pathologic T stage (ypT stage). Univariate logistic regression analysis was implemented to identify independent risk factors, including both clinical characteristics and IVIM histogram parameters. Subsequently, models for Clinical, Histogram, and Combined Clinical and Histogram were constructed using multivariable binary logistic regression analysis for the purpose of predicting pCR. The area under the receiver operating characteristic (ROC) curve (AUCs) was employed to evaluate the diagnostic performance of the three models. RESULTS: The values of D_ kurtosis, f_mean, and f_ median were significantly higher in the pCR group compared with the non-pCR group (all P < 0.05). The value of D*_ entropy was significantly lower in the pCR group compared with the non-pCR group (P < 0.05). The values of D_ kurtosis, f_mean, and f_ median were significantly higher in the low T stage group compared with the high T stage group (all P < 0.05). The value of D*_ entropy was significantly lower in the low T stage group compared with the high T stage group (P < 0.05). The ROC curves indicated that the Combined Clinical and Histogram model exhibited the best diagnostic performance in predicting the pCR patients with AUCs, sensitivity, specificity, and accuracy of 0.916, 83.33%, 85.23%, and 84.82%. CONCLUSIONS: The histogram parameters derived from IVIM have the potential to identify patients who have achieved pCR. Moreover, the combination of IVIM histogram parameters and clinical characteristics enhanced the diagnostic performance of IVIM histogram parameters.

Prediction and validation of pathologic complete response for locally advanced rectal cancer under neoadjuvant chemoradiotherapy based on a novel predictor using interpretable machine learning.

BACKGROUND: Precise evaluation of pathological complete response (pCR) is essential for determining the prognosis of patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy (NCRT) and can offer clues for the selection of subsequent treatment strategies. Most current predictive models for pCR focus primarily on pre-treatment factors, neglecting the dynamic systemic changes that occur during neoadjuvant chemoradiotherapy, and are constrained by low accuracy and lack of integrity. PURPOSE: This study devised a novel predictor of pCR using dynamic alterations in systemic inflammation-nutritional marker indexes (SINI) during neoadjuvant therapy and developed a machine-learning model to predict pCR. METHODS: Two cohorts of patients with LARC from center one from 2012 to 2017 and from center two from 2020 to 2023 were integrated for analysis. This study compared dynamic changes in blood indexes before and after neoadjuvant therapy and surgical operation. A least absolute shrinkage and selection operator (LASSO) regression analysis was conducted to mitigate collinearity and identify key indexes, constructing the SINI. Univariate and multiple logistic regression analyses were used to identify the independent risk factors associated with pCR. Additionally, 10 machine learning algorithms were employed to develop predictive models to assess risk. The hyperparameters of the machine learning models were optimized using a random search and 10-fold cross-validation. The models were assessed by examining various metrics, including the area under the receiver operating characteristic curves (AUC), the area under the precision-recall curve (AUPRC), decision curve analysis, calibration curves, and the precision and accuracy of the internal and external validation cohorts. Additionally, Shapley's additive explanations (SHAP) were employed to interpret the machine learning models. RESULTS: The study cohort comprised 677 patients from the center one and 224 patients from the center two. Six key indexes were identified, and a predictive index, SINI, was constructed. Univariate and multiple logistic regression analyses revealed that SINI, clinical T-stage, clinical N-stage, tumor size, and the distance from the anal verge were independent risk factors for pCR in patients with LARC following NCRT. The mean AUC value of the extreme gradient boosting (XGB) model in the 10-fold cross-validation of the training set was 0.877. The XGB model demonstrated superior performance in the internal and external validation sets. Specifically, in the internal test set, the XGB model achieved an AUC of 0.86, AUPRC of 0.707, accuracy of 0.82, and precision of 0.80. In the external validation set, the XGB model exhibited an AUC of 0.83, AUPRC of 0.702, accuracy of 0.81, and precision of 0.81. Additionally, the predictions generated by the XGB model were analyzed using SHAP. CONCLUSION: This study involved developing and validating an XGB model using SINI to predict pCR in patients with LARC. Besides, a SINI-based machine learning model shows promise in accurately predicting pCR following NCRT in patients with resectable LARC, offering valuable insights for personalized treatment approaches.

Replacing manual planning with automatic iterative planning for locally advanced rectal cancer VMAT treatment.

PURPOSE: To develop and implement a fully automatic iterative planning (AIP) system in the clinical practice, generating volumetric-modulated arc therapy plans combined with simultaneous integrated boost technique VMAT (SIB-VMAT) for locally advanced rectal cancer (LARC) patients. METHOD: The designed AIP system aimed to automate the entire planning process through a web-based service, including auxiliary structure generation, plan creation, field configuration, plan optimization, dose calculation, and plan assessment. The system was implemented based on the Eclipse scripting application programming interface and an efficient iterative optimization algorithm was proposed to reduce the required iterations in the optimization process. To verify the performance of the implemented AIP system, we retrospectively selected a total of 106 patients and performed dosimetric comparisons between the automatic plans (APs) and the manual plans (MPs), in terms of dose-volume histogram (DVH) metrics, homogeneity index (HI), and conformity index (CI) for different volumes of interest. RESULT: The AIP system has successfully created 106 APs within clinically acceptable timeframes. The average planning time per case was 36.8 ± 6.5 min, with an average iteration number of 6.8 (±1.1) in plan optimization. Compared to MPs, APs exhibited better performance in the planning target volume conformity and hotspot control ( p < 0.001 $p < 0.001$ ). The organs at risk (OARs) sparing was significantly improved in APs, with mean dose reductions in the femoral heads, the bone marrow, and the SmallBowel-Avoid of 0.53 Gy, 1.18 Gy, and 1.00 Gy, respectively ( p < 0.001 $p < 0.001$ ). Slight improvement was also observed in the urinary bladder V 40 Gy ${{V}_{40{\mathrm{\ Gy}}}}$ and the small bowel D 2 cc ( p < 0.001 ) ${{D}_{2{\mathrm{\ cc}}}}\ (p < 0.001)$ . Additionally, quality variation between plans from different planners was observed in DVH metrics while the APs represented better plan quality consistency. CONCLUSION: An AIP system has been implemented and integrated into the clinical treatment planning workflow. The AIP-generated SIB-VMAT plans for LARC have demonstrated superior plan quality and consistency compared with the manual counterparts. In the meantime, the planning time has been reduced by the AIP approach. Based on the reported results, the implemented AIP framework has been proven to improve plan quality and planning efficiency, liberating planners from the laborious parameter-tuning in the optimization phase.

The Role of Frailty in the Treatment of Locally Advanced Rectal Cancer.

Owing to the gradual aging of today's population, an increase in the prevalence of frailty syndrome has been noticed. This complex state of health, characterized by decreased resilience and tolerance with concurrent increased vulnerability to stressors and adverse health-related factors, has drawn researchers' attention in recent years. Rectal cancer, which constitutes ~30% of all colorectal cancers, is a disease noticeably related to the elderly. In its locally advanced form, it is conventionally treated with trimodal therapy-neoadjuvant chemoradiotherapy followed by total mesorectal excision and adjuvant chemotherapy. Despite its good clinical outcomes and improvement in rectal cancer local control, as evidenced by clinical trials, it remains unclear if all frail patients benefit from that approach since it may be associated with adverse side effects that cannot be handled by them. As old patients, and frail ones even more noticeably, are poorly represented in the clinical trials describing outcomes of the standard treatment, this article aims to review the current knowledge on the trimodal therapy of rectal cancer with an emphasis on novel approaches to rectal cancer that can be implemented for frail patients.

Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: How to Select the Most Suitable?

Rectal cancer shows specific characteristics in terms of pattern of recurrence, which occurs commonly at both local and distant sites. The standard of care for locally advanced rectal cancer (LARC) including neoadjuvant chemoradiotherapy, followed by surgery based on the total mesorectal excision principles leads to a reduction in the rates of local recurrences to 6-7% at 5 years. However, the outcomes among those with high-risk lesions remain unsatisfactory. On the contrary, neoadjuvant chemoradiotherapy results in long-term morbidities among those with low-risk lesions. Furthermore, the overall survival benefit of neoadjuvant therapy is still a subject to be debated, except for patients with complete or near-complete response to neoadjuvant therapy. Total neoadjuvant therapy (TNT) is a new paradigm of management of high-risk rectal cancer that includes early administration of the most effective systemic therapy either before or after neoadjuvant radiotherapy with or without chemotherapy prior to surgery with or without adjuvant chemotherapy. TNT potentially improves disease-free survival, even though whether it can prolong survival has been debatable. Recently, neoadjuvant chemotherapy only has been proved to be non-inferior to neoadjuvant chemoradiotherapy in patients with low-risk lesions. This review intends to review the current evidences of neoadjuvant therapy and propose a more customized paradigm of management of LARC.

Impact of Dose-Escalated Chemoradiation on Pathological Complete Response in Patients with Locally Advanced Rectal Cancer.

Locally advanced rectal cancer requires a multimodal treatment. Radiotherapy is being explored for intensification to improve the rates of pathological complete responses (ypCR rates) which are correlated with better outcomes. This study reports a comparison between standard versus escalated doses in a preoperative scenario. The ypCR rates, toxicity, postoperative complications, and disease-free and overall survival at 5 years are described. From 2012 to 2019, 99 patients were analyzed retrospectively: standard arm (mean of 47.5 Gy) vs. dose-escalated arm (mean of 54.3 Gy). All patients were treated with 3DRT in 25 fractions, with concomitant capecitabine and surgery performed according to the total mesorectal excision principles in both arms. The ypCR was reported using the "College of American Pathologist grades"; the gastrointestinal (GI) and genitourinary (GU) toxicity was reported using the "Common Terminology Criteria for Adverse Events" (CTCAE 4.0). The ypCR rates were higher in the dose-escalated group (25% vs. 10.64%; p = 0.07), with a lower rate of non-treatment response (61.36% vs. 38.64%; p = 0.11). No statistical differences between the arms were found in terms of the oncological outcomes, postoperative complications (p = 0.15), second surgeries (p = 0.62), or deaths (p = 0.62). The CTCAE acute GI and GU toxicity were grade I or II in both arms. Our study presents a long-term follow-up in comparative cohorts.

Total Neoadjuvant Therapy Versus Neoadjuvant Chemoradiation for Locally Advanced Rectal Cancer: A Multi-Institutional Real-World Study.

Total neoadjuvant therapy (TNT) has emerged as a promising approach for managing locally advanced rectal cancer (LARC), aiming to enhance resectability, increase pathological complete response (pCR), improve treatment compliance, survival, and sphincter preservation. This study compares the clinical outcomes of TNT, with either induction or consolidation chemotherapy, to those of the standard chemoradiotherapy (CRT). In this retrospective multi-institutional study, patients with stage II-III LARC who underwent CRT or TNT from seven oncology centers between 2021 and 2024 were retrospectively analyzed. The TNT group was categorized into induction or consolidation groups based on the sequence of chemotherapy and radiotherapy. Clinical and pathological data and treatment outcomes, including pCR, event-free survival (EFS), and overall survival (OS), were analyzed. Among the 276 patients, 105 received CRT and 171 underwent TNT. The TNT group showed significantly higher pCR (21.8% vs. 2.9%, p < 0.001) and lower lymphatic (26.3% vs. 42.6%, p = 0.009), vascular (15.8% vs. 32.7%, p = 0.002), and perineural invasion rates (20.3% vs. 37.6%, p = 0.003). Furthermore, 16.9% of TNT patients opted for non-operative management (NOM), compared to 0.9% in the CRT group (p < 0.001). The median interval between the end of radiotherapy and surgery was longer in the TNT group (17.6 weeks vs. 8.8 weeks, p < 0.001). The 3-year EFS was 58.3% for CRT and 71.1% for TNT (p = 0.06). TNT is associated with higher pCR, lower lymphatic and vascular invasion rates, and higher rates of NOM compared to CRT. This supports the use of TNT as a viable treatment strategy for LARC, offering potential benefits in quality of life.

B7H3 Immune Checkpoint Overexpression Is Associated with Decreased Complete Response Rates to Neoadjuvant Therapy in Locally Advanced Rectal Cancer.

BACKGROUND AND OBJECTIVES: Rectal cancer accounts for approximately one-third of colorectal cancers, with over 340,000 deaths globally in 2022. Despite advancements in treatment, the five-year overall survival for locally advanced rectal cancer (LARC) remains at 74%, with significant morbidity. B7H3 (CD276), an immune checkpoint protein, plays a role in tumor progression and resistance to therapy, and correlates with poor prognosis in various cancers, including colorectal cancer. This study aims to evaluate the expression of B7H3 in LARC and its impact on overall complete response (oCR) rates to neoadjuvant therapy. METHODS: A retrospective study was conducted on 60 patients with LARC who received neoadjuvant chemoradiation (nCRT) followed by total mesorectal excision (TME). B7H3 expression was assessed using immunohistochemistry on surgical specimens. Expression levels were categorized as high or low based on a composite score, and their association with oCR rates was analyzed. RESULTS: High B7H3 expression was observed in 60% of patients, with 73.5% showing expression in more than 50% of tumor cells. Patients who achieved oCR had significantly lower B7H3 expression compared to those with residual disease (p < 0.001). No nuclear expression of B7H3 was detected. No significant correlation was found between B7H3 expression and other clinicopathological variables, except for a higher likelihood of non-restorative surgery in patients with elevated B7H3 levels (p = 0.049). Mucinous adenocarcinoma had high expression of B7H3. CONCLUSIONS: Elevated B7H3 expression is associated with reduced oCR rates in LARC, highlighting its potential role as a prognostic biomarker. Further studies with larger cohorts are warranted to validate these findings and explore B7H3-targeted therapies as a treatment strategy for LARC.