Chemotherapy with preoperative radiotherapy in rectal cancer

Trends and Predictors of Total Neoadjuvant Therapy in Rectal Cancer: A Bi-National Registry Study Across Australia and New Zealand

BACKGROUND

Total Neoadjuvant Therapy (TNT) has significantly improved outcomes in locally advanced rectal cancer. Despite rising use and inclusion in international guidelines, adoption patterns in Australia and New Zealand (ANZ) remain unclear. This study determines bi-national patterns and predictors of TNT utilisation over a 6-year period.

METHODS

A retrospective population-based bi-national registry cohort study analysed data from the ANZ Bowel Cancer Outcome Registry from 2018 to 2024. Patients diagnosed with primary locally advanced rectal cancer (LARC) and treated with standard neoadjuvant therapy (SNT), consisting of long-course chemoradiotherapy or short-course radiotherapy, or TNT were included. The primary outcome was the incidence of TNT utilisation over time and determining pre-treatment predictive factors.

RESULTS

Of 33 270 patient entries, 3234 eligible LARC patients were identified, with 706 (21.8%) receiving TNT and 2528 (78.2%) receiving SNT. TNT usage increased from 11% in 2018 to 41% in 2023. On multivariable logistic regression, independent factors associated with decreased TNT use were older age (OR: 0.978, 95% CI: 0.970-0.985, p < 0.001), absence of multidisciplinary team discussion (OR: 0.113, 95% CI: 0.027-0.472, p = 0.003) and private health insurance (OR: 0.619, 95% CI: 0.441-0.869, p = 0.006). Factors associated with increased TNT use were clinical T4 tumours (OR: 2.020, 95% CI: 1.245-3.280, p = 0.004), node-positive status (OR: 1.481, 95% CI: 1.118-1.964, p = 0.006) and diagnosis during the years 2019-2023 (p < 0.05 for all).

CONCLUSIONS

TNT is increasingly used in surgical rectal cancer patients captured in the BCOR in ANZ. This study provides a baseline for future benchmarking patterns of rectal cancer management.

Short- and long-term outcomes of robot-assisted versus laparoscopic lateral lymph node dissection for rectal cancer

PURPOSE

The lateral pelvic cavity is an anatomically tricky site to access using a linear approach; therefore, robot-assisted lateral lymph node dissection (LLND) may be superior over existing laparoscopic procedures. In this study, we aimed to compare the short- and long-term outcomes of robot-assisted LLND (R-LLND) versus laparoscopic LLND (L-LLND) for locally advanced low rectal cancer and explore the potential advantages of robot-assisted surgery.

METHODS

This single-center, retrospective cohort study included patients aged ≥ 18 years who underwent minimally invasive total mesorectal excision (TME) plus LLND for low rectal adenocarcinoma. Patients were divided into L-LLND and R-LLND groups. The short- and long-term outcomes of the procedures were compared.

RESULTS

There were 41 patients in the L-LLND group and 21 in the R-LLND group. The incidence of postoperative complications was significantly lower in the R-LLND group (49% vs. 19%, p = 0.029), especially urinary retention (29% vs. 5%, p = 0.046). The median postoperative hospital stay was significantly shorter in the R-LLND group (22 vs. 15 days, p < 0.001). The 3-year relapse-free survival rates in the L-LLND and R-LLND groups were 75.3% (95% confidence interval [CI]: 58.9-85.9) and 65.7% (95% CI: 30.7-86.1), respectively. No significant differences were observed in long-term survival outcomes.

CONCLUSION

Patients with locally advanced rectal cancer who underwent TME plus R-LLND had a significantly lower incidence of postoperative complications and a significantly shorter postoperative hospital stay compared to those who underwent TME plus L-LLND. The long-term outcomes were comparable, and no oncological concerns associated with R-LLND were observed.

Evaluating the Impact of Induction and Consolidation Total Neoadjuvant Therapies Compared to Conventional Chemoradiotherapy for Locally Advanced Rectal Cancer: A Systematic Review and Network Meta-analysis

BACKGROUND

Total neoadjuvant therapy has been introduced to enhance oncological outcomes and minimize toxicity in locally advanced rectal cancer, but the superiority between the induction and consolidation of therapy remain unclear.

OBJECTIVE

To evaluate oncological and postoperative outcomes by comparing induction chemotherapy and consolidation chemotherapy with conventional chemoradiotherapy in patients with locally advanced rectal cancer.

DATA SOURCES

Systematic searches of PubMed, Embase, and Cochrane databases wereperformed for studies published from the database's inception until June 2023.

STUDY SELECTION

The inclusion criteria were patients diagnosed with rectal cancer. Interventions included induction chemotherapy and consolidation chemotherapy, and comparisons were specified as conventional neoadjuvant chemoradiotherapy.

MAIN OUTCOME MEASURES

Primary outcomes were the rates of pathologic or clinical complete response, postoperative results, chemoradiotherapy-related toxicity, and survival outcomes.

RESULTS

Thirty-three studies, encompassing patients from 1991 to 2021, were eligible for analysis. In network meta-analysis, a significantly increased OR for a pathologic complete response was observed in both the induction therapy group at 1.65 (95% credible interval, 1.18-2.30) and the consolidation therapy group at 1.87 (95% credible interval, 1.40-2.47) compared to conventional chemoradiotherapy. However, no difference was observed in complete response rates, postoperative results, or chemoradiotherapy-related toxicity grade 3 or higher between the groups. There were no differences among the groups in local recurrence, distant metastasis, or disease-free survival, whereas the induction group showed a nonsignificant improvement in overall survival.

LIMITATIONS

There was significant heterogeneity among the studies, and the short follow-up period in most studies limited the assessment of long-term survival outcomes.

CONCLUSIONS

Both induction and consolidation total neoadjuvant therapy increase the pathologic complete response rate in locally advanced rectal cancer without compromising safety or postoperative outcomes. However, total neoadjuvant therapy was not associated with a significant improvement in survival outcomes. Although total neoadjuvant therapy strategies for locally advanced rectal cancer are considered safe, additional long-term studies are needed.

TRIAL REGISTRATION NO

CRD42023445348.

Rectosigmoid Junction Cancer; The Role of Preoperative and Postoperative Radiation With Novel Nomogram in Predicting Survival in the United States

BACKGROUND

There is controversy and limited data the management of rectosigmoid junction cancer (RSJC), especially the role of radiation. We aim to investigate the role of preoperative and postoperative radiation in RSJC and whether this cancer should be treated as a colon cancer or as a rectal cancer.

METHODS

The data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and identified from 2000 to 2018.

RESULTS

Of the 50,779 patients, 87% were ≥50 years old, 56.2% were male, 80.8% were White. Regarding tumor characteristics, 76% were Grade II, while 22.7% had distant-stage. 16.4% of patients were treated with multimodal therapy (surgery with chemoradiation), 47.9% surgery alone, 6.5% of patients received preoperative radiation, and 9.9% received postoperative radiation. Regarding prognostic significance of pre-operative and postoperative radiation factors, we evaluated factors, such as age, gender, race, tumor size, histologic variants of adenocarcinoma, and tumor grade. Patients with distant-staged tumors who received preoperative radiation had lower mortality compared to those who received postoperative radiation (95% CI, 0.73 - 0.97, (hazard ratio (HR) = 0.85, p = 0.04). There were no survival differences for localized or regional disease regarding pre and postoperative radiation, or when sub-stratifying for any other significant demographic or tumor characteristics.

CONCLUSION

Surgery with adjuvant chemoradiation had the best prognosis for all demographic and tumor characteristics. Preoperative radiation had a good prognosis only in distant disease. However, further randomized evidence is required to demonstrate the efficacy of pre-and post-operative radiation in rectosigmoid junction cancer.

Contouring atlas and essential points for radiotherapy in rectal cancer

In the last decade, the role of radiotherapy in rectal cancer has changed significantly with the introduction of total neoadjuvant therapy (TNT) and nonoperative management (NOM). For the setting of irradiation field in rectal cancer, the pararectal, lateral lymph nodes, and those along the inferior mesenteric artery (IMA) are most important. In total mesorectal excision (TME), the root of the IMA is dissected. In the atlas of pelvic irradiation for rectal cancer, the setting of the upper margin of the mesorectum varies from atlas to atlas, and no atlas sets the upper margin of the mesorectum to the root of the IMA. In particular, there is no consensus on the definition of anatomical boundaries regarding the lymph nodes along the superior rectal artery (SRA). The upper margin of the irradiation field in clinical trials of preoperative radiotherapy and TNT is generally set at the level of the internal and external iliac artery branches, L5/S1, or S2/S3. However, it is not necessary to include the entire mesorectum to the root of the IMA in patients undergoing preoperative radiotherapy plus TME. Conversely, for patients receiving NOM, the irradiation field may have to include the mesorectum to the IMA root, though the incidence of lymph node metastasis and gastrointestinal adverse events merits consideration. It is increasingly important to determine the extent of clinical target volume around the SRA region and the setting of the upper margin of the irradiation field after formulating the treatment policy together with the surgeons and medical oncologists.

Total Neoadjuvant Therapy Versus Conventional Neoadjuvant Therapy for Rectal Cancer: Cost Analysis in a Public Healthcare System

PURPOSE

Total neoadjuvant therapy (TNT) has become the standard of care in locally advanced rectal cancer, but its economic impact is unclear. This study compares the cost of TNT with conventional neoadjuvant therapy (CNT), consisting of either short-course radiotherapy or long-course chemoradiotherapy, within a universally funded public healthcare system.

METHODOLOGY

A trial-based costing analysis was conducted from a third-party payer's perspective with a 2-year time horizon, following CHEERS guidelines. Consecutive patients with rectal cancer treated with neoadjuvant therapy from 2014 to 2023 were extracted from a multi-institutional database. Inpatient, outpatient, imaging and pathology resource costs were extracted and adjusted to 2024 AUD with a 5% discount rate. Primary outcomes were overall cost per cohort and mean per patient cost. Secondary outcomes were overall and mean cost per cost category. Sensitivity analysis explored the influence of discount rates and inflation methods.

RESULTS

Of 115 eligible patients, 60 (52.2%) received CNT and 55 (47.8%) received TNT. Overall treatment costs for the cohorts were $8 429 710.66 (CNT) and $6 992 616.67 (TNT), with mean per patient costs of $140 495.18 (CNT) and $127 138.48 (TNT). Overall per patient costs were $13 356.70 (9.51%) lower for TNT patients, mainly driven by lower mean inpatient costs ($78 523.53 vs. $96 843.08, 18.9%). TNT increased outpatient ($43 001.18 vs. $39 376.12, 9.21%), imaging ($4179.13 vs. $2973.61, 40.5%) and pathology ($1434.65 vs. $1302.38, 10.1%) costs. The results were robust to sensitivity analysis.

CONCLUSION

TNT is less costly than CNT within a universally funded public healthcare system, primarily due to reduced inpatient costs associated with higher rates of organ preservation.

Optimizing total neoadjuvant therapy in locally advanced rectal cancer: risk stratification should not be overlooked

Chemoradiotherapy plus total mesorectal excision has been established as the standard treatment for locally advanced rectal cancer (LARC) and can achieve satisfactory local control. However, systemic control of LARC, especially in patients with risk factors for poor prognosis, is still of concern. As application of total neoadjuvant therapy (TNT) has been proposed as a potential solution, a clearer risk stratification of LARC to guide individual treatment is needed. Combination therapy such as targeted therapy or immunotherapy can be used to increase treatment intensity for high-risk LARC. In this review, we evaluate recent trials of several treatment modalities, specifically focusing on intensified TNT regimens for high-risk LARC with the goal of summarizing optimal clinical strategies and future study designs.

Immunotherapy in microsatellite-stable colorectal cancer: Strategies to overcome resistance

Colorectal cancer (CRC) is among the foremost causes of cancer-related mortality worldwide; however, individuals with microsatellite-stable (MSS) disease-who constitute most CRC diagnoses-derive limited benefit from existing immunotherapeutic approaches. Here, we outline emerging methods designed to address the inherent resistance of MSS CRC to immune checkpoint inhibitors (ICIs). Recent findings emphasize how the immunosuppressive tumor microenvironment (TME) in MSS CRC, marked by diminished immunogenicity and high levels of regulatory T cells and myeloid-derived suppressor cells, restricts effective antitumor immune activity. Combination regimens that merge ICIs with chemotherapy, anti-angiogenic agents, or targeted blockade of pathways such as TGF-β and VEGF have shown encouraging early outcomes, including enhanced antigen presentation and T-cell penetration. Novel immunomodulatory platforms-such as epigenetic modifiers, oncolytic viruses, and engineered probiotic vaccines-are under assessment to further reprogram the TME and boost therapeutic efficacy. Concurrently, progress in adoptive cell therapies (for example, chimeric antigen receptor (CAR) T cells) and the development of cancer vaccines targeting tumor-associated and neoantigens promise to extend immune control over MSS CRC. In parallel, improving patient selection through predictive biomarkers-from circulating tumor DNA (ctDNA) to gene expression signatures and specific molecular subtypes-could refine individualized treatment strategies. Finally, interventions that alter the gut microbiome, including probiotics and fecal transplantation, serve as complementary tools to strengthen ICI responses. Taken together, these insights and combined treatment strategies lay the foundation for more successful immunotherapeutic interventions in MSS CRC, ultimately aiming to provide sustained clinical benefits to a broader spectrum of patients.

Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: long-term results of a randomized controlled trial

BACKGROUND AND PURPOSE

Short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are the primary neoadjuvant radiotherapy schedules for locally advanced rectal cancer. Recent research has questioned the efficacy of SCRT. This study presents an updated analysis of our previous research, extending the follow-up to evaluate 5-year outcomes by comparing the long-term results of these two strategies.

MATERIALS AND METHODS

This randomized controlled trial compared SCRT and LCRT in locally advanced middle or high rectal adenocarcinoma. The SCRT group received 25 Gy/5 fractions over 1 week plus CAPOX, while the LCRT group received 50-50.4 Gy/25-28 fractions over 5-5.5 weeks plus capecitabine. All patients received consolidation chemotherapy and then underwent delayed surgery after 8 weeks or more post-radiotherapy. The endpoints of this updated analysis include overall survival (OS),disease-free survival (DFS), locoregional recurrence (LR) and distant metastasis (DM).

RESULTS

Ninety-nine cases (45 LCRT, 54 SCRT) were followed for a median of 4.7 years. Five-year OS rates were 77.3% for LCRT vs. 65.6% for SCRT group (P = 0.4). The 5-year DFS rates were 69.6% for LCRT vs. 54.9% for SCRT (P = 0.07). Cox regression indicated no prominent difference between the two groups regarding OS, LR, or DM. Subgroup analysis demonstrated a significantly better DFS with LCRT compared to SCRT in male patients ([HR] = 2.48, 95%CI: 1.04-5.93, P = 0.03), patients under the age of 60 (HR = 3.19, 95%CI: 1.03-9.92, P = 0.04), and cT4 patients (HR not calculated: no events in LCRT group, P = 0.004).

CONCLUSION

DFS showed a trend in favor of the LCRT group, with LCRT being significantly superior among men, patients under 60, and cT4 stage. Despite being intensified, SCRT failed to achieve long-term outcomes comparable to LCRT. Further research is needed to compare these two approaches in the context of total neoadjuvant treatment.

TRIAL REGISTRATION DATA

IRCT2017110424266N3 (Registration date: 2017-11-12).  https://irct.behdasht.gov.ir/trial/20526 .

Clinical feasibility of treatment planning on a diagnostic CT scan without or with single fraction plan adaptation in patients with stage II/III rectal cancer

BACKGROUND

With the ultimate aim of reducing time to start radiotherapy treatment in patients with rectal cancer, this study explores the feasibility of omitting a planning CT scan (pCT), by utilizing the diagnostic CT scan (dCT) for treatment planning, with or without plan adaption using online adaptive radiotherapy.

METHODS

Fifteen rectal cancer patients, with both dCT and pCT available, were included. Target volumes and organs at risk (OARs) were delineated on both scans, followed by treatment planning based on the dCT contours. Plans were recalculated on the pCT to assess dosimetric differences for target volumes and OARs. Additionally, five patients with HyperSight CBCT scans underwent a similar planning process. An online adaptive treatment workflow was simulated using the Ethos system, where the dCT and its plan served as the reference, and the HyperSight CBCT was used for adaptation.

RESULTS

dCT-based plans showed adequate target volume coverage. However, when recalculated on the pCT, median coverage decreased for both CTV and PTV, and OAR doses increased. None of the 15 plans met prescribed constraints without online adaptive radiotherapy. In contrast, for all five patients in the adaptive workflow, the treatment plans met target volume coverage and OAR constraints.

CONCLUSION

Using dCT-based treatment planning is feasible for rectal cancer patients but requires at least one online adaptive session. A prospective trial (MEC 2023-0445) is ongoing in patients with rectal cancer, aiming to reduce time to start treatment, by omitting the pCT and using online adaptive radiotherapy workflow.

Neoadjuvant Treatment of Rectal Cancer: A Repeat UK-wide Survey After Implementation of National Intensity Modulated Radiotherapy Guidance

AIMS

Rectal cancer management has changed significantly in the last decade with the introduction of total neoadjuvant therapy (TNT), minimally invasive surgery, brachytherapy, and organ preservation. A national survey of intensity modulated radiotherapy (IMRT) was carried out in 2020 to support the development of national Royal College of Radiologists (RCR) guidance, published in 2021. We performed a repeat survey in collaboration with the RCR, to inform iterations of the RCR Guidance and establish treatment patterns across the UK to facilitate future research and development.

MATERIALS AND METHODS

A web-based survey was developed and tested by the authors prior to dissemination by the RCR to all UK radiotherapy centres. The repeat survey requested details and strategies of current radiotherapy techniques, including details on setup, doses, organs at risk, peer review, and verification, and asked for the standard management of 5 clinical cases within each multidisciplinary team (MDT) serving that radiotherapy centre. Descriptive statistical analysis was carried out.

RESULTS

In total, 42 of 60 (70%) of the NHS centres across the UK answered the repeat IMRT rectal survey, which reflected 70 MDTs answering the clinical scenarios questions. 100% of centres that responded are routinely using IMRT, with 95% of centres using it in all patients. Variation in treatment delivery has reduced since the previous survey. The greatest difference is still in the use of simultaneous integrated boost and definition of organs at risk. The management for the clinical cases was widely different, with answers generally equally distributed between 2-4 options. The highest-scoring treatment strategies ranged from 24% to 57%.

CONCLUSION

RCR guidance has helped standardise the delivery of radiotherapy to treat rectal cancer in the UK. The variation in neoadjuvant treatment represents an exciting, evolving time in rectal cancer management. Clinical trials are needed to further homogenise treatment, but a degree of national variation is likely to continue.

Baseline Magnetic Resonance Imaging Assessment of Circumferential Resection Margin Predicts Long-term Survival in Rectal Adenocarcinoma: Experience from a Tertiary Care Center

In rectal adenocarcinoma, the diagnostic accuracy of baseline MRI for predicting circumferential resection margin (CRM) is established. However, data regarding the role of baseline and post-neoadjuvant chemoradiotherapy (NACTRT) MRI-mesorectal fascia (MRI-MRF)-positive status in predicting long-term oncological outcomes is relatively scarce and heterogeneous. The objective of the study is to evaluate the long-term oncological survival outcomes of baseline and post-neoadjuvant chemoradiation (NACTRT) MRI-MRF as predictors of long-term survival outcomes, i.e., overall survival (OS), disease-free survival (DFS), and locoregional recurrence-free survival (LRFS). Single center retrospective analysis from a prospectively maintained database. Patients undergoing curative surgery for rectal adenocarcinoma either upfront or post-NACTRT between July 2013 and April 2014. Patients with cT3/cT4 or N + received NACTRT before surgery. The pre-NACTRT MRI was recorded as MRI 1-MRF and post-NACTRT MRI was recorded as MRI 2-MRF. MRI scans done at presentation irrespective of further treatment were labeled as MRI T-MRF. Out of 254 patients, 217 were eligible for analysis. The median follow-up duration is 132 months. Seventy-six percent of patients received NACTRT. Overall, recurrences were seen in 68/217 (31.3%) patients, with 18 local and 50 distant recurrences. Eighty-six (39.6%) deaths were recorded, most due to disease progression. The 5-year OS of the cohort was 69.1% (95% C.I 63–75.8); 5-year DFS was 67.4% (95% C.I 61.2–74.3); and the 5-year LRFS was 91% (95% C.I 87–95.2). MRI T-MRF status was significantly associated in predicting OS, DFS, and LRFS. MRI 1-MRF status is a strong predictor for OS and DFS. The MRI 2-MRF status is a weak predictor for OS and is not associated with DFS and LRFS. The path-CRM-positive status is a significant predictor of OS and DFS, however not for LRFS. Baseline MRI-MRF status is a robust and strong predictor of long-term survival outcomes (OS, DFS, LRFS). Patients with baseline MRI-CRM-positive status have poorer outcomes irrespective of neoadjuvant therapy and poor histology features.

Transanal total mesorectal excision for locally advanced rectal cancer following neoadjuvant chemoradiotherapy

PURPOSE

To examine the clinical impact of transanal total mesorectal excision (TaTME) for locally advanced rectal cancer after neoadjuvant chemoradiotherapy (NACRT).

METHODS

This retrospective study included 91 patients undergoing surgery for rectal cancer after NACRT between 2011 and 2022. Among them, 24, 22, and 45 patients underwent open (Open), conventional laparoscopic (Lap), and TaTME surgeries, respectively. We compared their clinical outcomes.

RESULTS

Operative time, blood loss, transfusion, morbidity, and hospital stay were significantly lower in the TaTME group than in the Open or Lap groups. The multivariate regression analyses identified only the TaTME approach as a significant factor for reducing morbidity. Both 3 yrear relapse-free survival (RFS) and local recurrence-free survival (LRFS) were significantly better in the TaTME group than in the Open or Lap groups (3 yr RFS: 94.7%, 80.4%, and 66.7%, and 3 yr LRFS: 100%, 90.5%, and 82.2% for the TaTME, Lap, and Open groups, respectively). Multivariate analyses of potential risk factors for recurrence identified body mass index, combined resection, and pathological stage, but not the TaTME approach, as significant predictors of recurrence.

CONCLUSION

TaTME reduced morbidity significantly in patients with locally advanced rectal cancer undergoing NACRT, compared with open or laparoscopic surgery.

Patterns of Care and Oncologic Outcomes after Pelvic Exenteration for Locally Advanced Rectal Cancer in the United States

BACKGROUND

Pelvic exenterations (PEs) are technically demanding procedures performed with curative intent for advanced malignancies to improve patient survival while balancing morbidity and functional outcomes. The majority of United States (US) data regarding PE for rectal cancers originate from single-center series.

OBJECTIVE

We aimed to investigate patterns of care and oncologic outcomes for primary rectal cancer patients undergoing PE in a national registry.

METHODS

The National Cancer Database (2004-2019) was queried for adults with a pT4 rectal adenocarcinoma. Logistic regression identified factors associated with positive margins. Multivariable Cox regression estimated treatment effects on overall survival (OS).

RESULTS

Of 673 patients (73% <65 years of age, 39% male, 82% White), median follow-up was 39 months. The majority received neoadjuvant chemotherapy (76%) and radiation (75%), while adjuvant chemotherapy (37%) and radiation (13%) were less common. Twenty-four percent had positive margins (R1 = 98, R2 = 11, R + NOS = 48). Univariable analysis demonstrated that only nodal involvement was associated with higher positive margin rates (odds ratio 1.75, 95% confidence interval [CI] 1.22-2.51). Five-year OS for R0 and R+ resections were 55% and 33%, respectively. On multivariable analysis, age <65 years (hazard ratio [HR] 0.73, 95% CI 0.53-0.99) and adjuvant chemotherapy (HR 0.62, 95% CI 0.47-0.82) were associated with improved OS, while N+ status (HR 2.13, 95% CI 1.67-2.70) and positive margins (HR 1.82, 95% CI 1.41-2.35) portended worse prognosis. No significant associations were observed between outcomes and institutional volume.

CONCLUSION

One in four US patients undergoing PE for locally advanced rectal cancer had an R+ resection regardless of center volume. Quality of surgical resection to achieve negative margins remains the most relevant prognostic factor.

Survival benefit and impact of adjuvant chemotherapy following neoadjuvant therapy in patients with locally advanced rectal cancer

The controversy surrounding the continuation of postoperative adjuvant chemotherapy (AC) for locally advanced rectal cancer patients who underwent neoadjuvant therapy (NAT) still existed. The study aimed to identify the individuals that would benefit from AC from those with stage ypII/III rectal cancer. Data for this retrospective study were obtained from the Surveillance, Epidemiology, and End Results (SEER) database and the local database. Subgroup differentiation of the beneficiary population by classification and regression tree analysis. The primary endpoint was overall survival (OS). 15,671 patients were included from the SEER database and 508 patients from local database. The proportions receiving AC were 41.9% in the SEER database and 77.6% in local database, respectively. Analysis results illustrated that the AC benefited population in the SEER database was characterized as: stage ypT4/N + patients (HR 0.75, 95% CI 0.69-0.82, p < 0.001); stage ypT3N0 patients aged 70 years or older (HR 0.69, 95% CI 0.56-0.83, p < 0.001). Moreover, stage ypT4/N + patients also significantly benefited from AC in local database (HR 0.48, 95% CI 0.31-0.74, p < 0.001). The analysis of the two databases showed that stage ypT3N0 patients aged < 70 years could not significantly benefit from AC (HR 0.90, p = 0.114 in the SEER database; HR 0.90, p = 0.960 in local database). Postoperative adjuvant chemotherapy provides a significant benefit in patients with stage ypT4/N + rectal cancer following neoadjuvant therapy. Our study discovered that locally advanced rectal cancer patients with aggressive tumors might benefit from postoperative adjuvant chemotherapy and prolonged the survival.

Learning curve analysis for prophylactic bilateral robot-assisted lateral lymph node dissection for lower rectal cancer: a retrospective study

BACKGROUND

Lateral lymph node dissection (LLND) is an important surgical procedure in the treatment of lower rectal cancer (RC). However, limited data are available regarding the learning curve for robot-assisted LLND (RA-LLND). This study aimed to evaluate the learning curve for prophylactic bilateral RA-LLND for lower RC.

METHODS

We retrospectively analyzed 58 consecutive patients with clinical stage II/III lower RC who had undergone prophylactic bilateral RA-LLND between July 2020 and June 2024. Cumulative sum (CUSUM) analysis was used to evaluate the learning curve for bilateral RA-LLND operative time.

RESULTS

The mean age of patients was 61.5 years, and mean body mass index was 23.4 kg/m2. The proportion of neoadjuvant therapy was 8.6%. Mean prophylactic bilateral RA-LLND operative time was 173.7 min. CUSUM analysis divided the learning curve for prophylactic bilateral RA-LLND operative time into three phases: initial learning phase (20 cases); competence phase (16 cases); and master/proficiency phase (subsequent cases). Mastery of surgical technique was achieved after performing the 36th case. Comparisons of surgical outcomes in terms of operative parameters and complications were made between phases 1 and 2 combined and phase 3. A significant reduction in mean prophylactic bilateral RA-LLND operative time was observed between phases 1 and 2 compared with phase 3 (P < 0.01). Mean blood loss was decreased in phase 3 (40.5 ml) compared to phases 1 and 2 combined (148.2 ml, P < 0.01). The frequencies of overall postoperative complications directly related to LLND and urinary dysfunction were significantly reduced in phase 3 compared to phases 1 and 2 combined (P = 0.04, and P = 0.02, respectively).

CONCLUSIONS

The three phases identified by CUSUM analysis represented characteristics of the learning curve for prophylactic bilateral RA-LLND. These data suggest that 20 cases are required for the early stage of the learning curve, whereas mastery level could be achieved after 36 cases.

Rectal cancer - French intergroup clinical practice guidelines for diagnosis, treatment, and follow-up (TNCD, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFP, RENAPE, SNFCP, AFEF, SFR, and GRECCAR)

BACKGROUND

This article summarizes the French intergroup guidelines regarding rectal adenocarcinoma (RA) management published in September 2023, available on the French Society of Gastroenterology website.

METHODS

This work was supervised by French medical and surgical societies involved in RA management. Recommendations were rated from A to C according to the literature until September 2023.

RESULTS

Based on the pretreatment work-up, RA treatment was divided into four groups. T1N0 can be treated by endoscopic or surgical excision alone if there is no risk factor for lymph node involvement. For T2N0, radical surgery with total mesorectal excision is recommended, but rectal conservation is possible for small tumors (<4cm) after complete/subcomplete response following chemoradiotherapy. For T12N+ or T3+any N, total neoadjuvant treatment (TNT) followed by radical surgery is the gold standard, but rectal conservation is possible for small tumors after complete/subcomplete response following TNT. T3N2 or T+any N are an indication for TNT followed by radical surgery. Immunotherapy shows promise for dMMR/MSI RA. For metastatic tumors, recommendations are based on less robust evidence and chemotherapy plays a major role.

CONCLUSION

These guidelines aim at providing a personalized therapeutic strategy and are constantly being optimized. Each case should be discussed by a multidisciplinary team.

The role of adjuvant chemotherapy in rectal cancer: A nationwide cohort study from the Netherlands

AIM

Treatment of rectal cancer has improved significantly over the past decades. However, the role of adjuvant chemotherapy remains a matter of debate. The aim of this study is to evaluate the association between adjuvant chemotherapy and overall survival of patients with rectal cancer.

METHOD

Data from the Netherlands Cancer Registry were used to evaluate all nonmetastatic pathological node-positive patients who underwent treatment for rectal cancer during the time period 2009-2020 in the Netherlands. Patients were grouped according to whether they received adjuvant chemotherapy. Patients were further divided into three groups according to the type of preoperative treatment. Propensity score matching (PSM) was applied based on patient-related variables, tumour-related variables and treatment-related variables. The matching procedure for PSM was done with nearest neighbour and without replacement employing a 1:1 ratio. Kaplan-Meier analysis was performed after PSM to compare overall survival.

RESULTS

A total of 7479 patients were included, of whom 865 (11.6%) underwent adjuvant chemotherapy. After PSM the no neoadjuvant treatment group included 240 patients per study arm, the neoadjuvant radiotherapy group 317 and the neoadjuvant chemoradiation group 182 patients. A significant difference in 5-year survival was found comparing adjuvant versus no adjuvant chemotherapy in all subgroups: no neoadjuvant treatment 54.6% vs. 40.8% (p = 0.003), neoadjuvant radiotherapy 77.0% vs. 53.9% (p < 0.001) and neoadjuvant chemoradiation 68.1% vs. 45.6% (p < 0.001).

CONCLUSION

Adjuvant chemotherapy was associated with an improved 5-year survival in all subgroups. The role of adjuvant chemotherapy in the treatment of rectal cancer should be reconsidered in node-positive patients.

Integrating radiomics, pathomics, and biopsy-adapted immunoscore for predicting distant metastasis in locally advanced rectal cancer

BACKGROUND

This study aimed to develop and validate a nomogram that utilized macro- and microscopic tumor characteristics at baseline, including radiomics, pathomics, and biopsy-adapted immunoscore (ISB), to accurately predict distant metastasis (DM) in patients with locally advanced rectal cancer (LARC) who underwent neoadjuvant chemoradiotherapy (nCRT).

MATERIALS AND METHODS

In total, 201 patients with LARC (91 months of median follow-up) were enrolled. Radiomics features were extracted from apparent diffusion coefficient maps and T2-weighted images. Pathomics features including global pattern (features of the entire image) and local pattern (features of the tumor nuclei) were extracted from whole-slide images of hematoxylin-eosin-stained biopsy specimens. ISB was calculated from the densities of CD3+ and CD8+ T cells in the tumor region using immunohistochemistry on biopsy specimens. The construction of a predictive model was carried out using the least absolute shrinkage and selection operator-Cox analysis, with performance metrics including the area under the curve (AUC) and concordance index (C-index) utilized for evaluation.

RESULTS

Compared with patients with moderate and high ISB, patients with low ISB exhibited significantly higher risk scores for radiomics and pathomics signatures. The nomogram showed respective C-indexes of 0.902 and 0.848 for 5-year DM-free survival in the training and test sets, along with corresponding AUC values of 0.950 and 0.872. Patients could be efficiently categorized into low- and high-risk groups for developing DM using the nomogram.

CONCLUSIONS

The nomogram integrating macroscopic radiological information and microscopic pathological information is effective for risk stratification at baseline in LARC treated with nCRT.

Intensity-modulated radiation therapy can reduce acute toxicities in long-course neoadjuvant radiation therapy combined with S-1 for locally advanced rectal cancer

BACKGROUND

The purpose of this study was to compare outcomes and adverse events between three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) in patients undergoing long-course neoadjuvant radiation therapy (NA-RT) for locally advanced rectal adenocarcinoma (LARC).

METHODS

We retrospectively analyzed a total of 47 consecutive patients who received NA-RT for LARC between January 2011 and September 2022. Seven and 40 patients were diagnosed with clinical stages II and III, respectively. The prescribed dose per fraction was 1.8 Gy for total doses of 45 or 50.4 Gy. Seventeen and 30 patients received 3D-CRT and IMRT, respectively. NA-RT was delivered with concurrent chemotherapy of oral administration of S-1.

RESULTS

Planned NA-RT was completed without any treatment interruption in 43 of the 47 patients. Two patients experienced treatment interruption, and two patients discontinued due to grade ≥ 3 toxicities. No significant differences were observed between patients receiving 3D-CRT and IMRT in local control, progression-free survival, and overall survival (P = 0.488, 0.259, and 0.636, respectively). Patients receiving IMRT showed significantly fewer non-hematological grade ≥ 2 acute toxicities than those receiving 3D-CRT (33.3% vs. 70.6%, P = 0.018). In addition, patients who received IMRT tended to have less intestinal toxicity of grade ≥ 2 than those who received 3D-CRT (P = 0.057).

CONCLUSION

IMRT significantly reduced grade ≥ 2 acute toxicities without compromising oncologic outcomes compared to 3D-CRT. Therefore, IMRT may be considered as a current standard treatment in the total neoadjuvant therapy era.

Impact of MRI risk assessment on the survival benefits of neoadjuvant chemoradiotherapy in patients with stage II-III rectal cancer: A retrospective cohort study

PURPOSE

To investigate whether MRI risk factors can be used to predict clinical outcomes and whether MRI risk assessment can be used to select stage II-III rectal cancer patients who may benefit from neoadjuvant chemoradiotherapy (nCRT).

METHODS AND MATERIALS

A total of 947 rectal cancer patients who underwent total mesorectal excision (TME) were retrospectively recruited. An MRI scoring system was established using the cumulative score of three risk factors (mesorectal fascia involvement, extramural venous invasion, and tumour deposits). Patients with mrT3c-T4 stage, N2 stage, or any risk factors were considered MRI high-risk cases of rectal cancer. Cox regression analysis was used to identify independent risk factors for overall survival (OS) and disease-free survival (DFS). Kaplan-Meier curves were generated to show the benefits of nCRT after propensity score matching (PSM).

RESULTS

OS and DFS were more favourable in the MRI low-risk group than in the MRI high-risk group, and the MRI scoring system facilitated prognostic stratification in stage II-III rectal cancer patients. NCRT significantly improved 3-year OS (89.1 % versus 78.8 %, p = 0.001) and 3-year DFS (73.4 % versus 68.0 %, p = 0.030) in the MRI high-risk group. After PSM, OS and DFS were improved in the MRI high-risk group with an MRI score of 1 (OS: HR = 0.432 [95 % CI: 0.214-0.871], p = 0.019; DFS: HR = 0.477 [95 % CI: 0.275-0.825], p = 0.008) and an MRI score of 2 (OS: HR = 0.276 [95 % CI: 0.130-0.586], p = 0.001; DFS: HR = 0.358 [95 % CI: 0.182-0.705], p = 0.003), whereas MRI low-risk patients did not obtain any survival benefit from nCRT.

CONCLUSIONS

MRI-defined high-risk patients with MRI scores of 1 or 2 may benefit from nCRT. Baseline MRI should be given more consideration in nCRT decision-making.

Prognostic Significance of Desmoplastic Reaction After Neoadjuvant Chemoradiotherapy in Advanced Rectal Cancer

BACKGROUND

Desmoplastic reaction is recognized as a prognostic factor in colorectal cancer. However, its significance in locally advanced rectal cancer after neoadjuvant chemoradiotherapy remains underexplored.

OBJECTIVE

To assess the prognostic value of desmoplastic reaction in specimens from patients with advanced rectal cancer after chemoradiotherapy.

DESIGN

This was a retrospective study.

SETTINGS

This study was conducted at a single comprehensive cancer center.

PATIENTS

The study included 255 patients with advanced rectal cancer who underwent fluoropyrimidine-based chemoradiotherapy followed by total mesorectal excision from 2005 to 2014. Desmoplastic reaction was classified into mature, intermediate, and immature categories based on histological analysis.

MAIN OUTCOME MEASURES

The primary outcomes were recurrence-free survival and overall survival.

RESULTS

Desmoplastic reaction was classified as mature (69.0%), intermediate (5.5%), or immature (25.5%). The mature group had a higher percentage of good responders (34.1%) compared with the intermediate (0%) and immature (4.6%) groups ( p < 0.0001). The mature group correlated with better outcomes, with a higher 5-year recurrence-free survival (85.4%) and overall survival (93.0%) as compared with intermediate (45.1% and 76.2%, respectively) and immature (65.8% and 88.8%, respectively) groups. In the multivariable analysis, intermediate/immature desmoplastic reaction was significantly associated with poorer recurrence-free survival ( p = 0.03). Among poor responders, intermediate/immature desmoplastic reaction was associated with poorer recurrence-free survival ( p = 0.03). Adjuvant chemotherapy did not significantly improve the 5-year recurrence-free survival rate for the mature group (adjuvant chemotherapy vs no chemotherapy, 86.4% vs 84.8%; p = 0.64), with worse trends observed in the intermediate/immature combined group (55.9% vs 69.4%, respectively, p = 0.27).

LIMITATIONS

The limitations include the subjective nature of the desmoplastic reaction assessment and the retrospective design of the study.

CONCLUSIONS

Desmoplastic reaction in surgical specimens after chemoradiotherapy is associated with responses to chemoradiotherapy and serves as a significant prognostic factor in advanced rectal cancer, particularly for those responding poorly to chemoradiotherapy. See Video Abstract .

IMPORTANCIA PRONSTICA DE LA REACCIN DESMOPLSICA TRAS LA QUIMIORRADIOTERAPIA NEOADYUVANTE EN EL CNCER RECTAL AVANZADO

ANTECEDENTES:La reacción desmoplásica se reconoce como un factor pronóstico en el cáncer colorrectal. Sin embargo, su importancia en el cáncer rectal localmente avanzado después de la quimiorradioterapia neoadyuvante sigue sin explorarse.OBJETIVO:Evaluar el valor pronóstico de la reacción desmoplásica en muestras de pacientes con cáncer rectal avanzado después de la quimiorradioterapia.DISEÑO:Este es un estudio retrospectivo.ESCENARIO:Este estudio se llevó a cabo en un solo centro oncológico integral.PACIENTES:El estudio incluyó a 255 pacientes con cáncer rectal avanzado que se sometieron a quimiorradioterapia basada en fluoropirimidina seguida de una escisión mesorrectal total entre 2005 y 2014. La reacción desmoplásica se clasificó en categorías madura, intermedia e inmadura según el análisis histológico.RESULTADOS PRINCIPALES:Los resultados primarios fueron la supervivencia sin recurrencia y la supervivencia general. RESULTADOS: La reacción desmoplásica se clasificó como madura (69,0%), intermedia (5,5%) o inmadura (25,5%). El grupo maduro tuvo un mayor porcentaje de buenos respondedores (34,1%) en comparación con los grupos intermedio (0%) e inmaduro (4,6%) (p < 0,0001). El grupo maduro se correlacionó con mejores resultados, con una mayor supervivencia libre de recurrencia a 5 años (85,4%) y supervivencia general (93,0%) en comparación con los grupos intermedio (45,1% y 76,2%, respectivamente) e inmaduro (65,8% y 88,8%, respectivamente). En el análisis multivariable, la reacción desmoplásica intermedia/inmadura se asoció significativamente con una peor supervivencia libre de recurrencia ( p = 0,03). Entre los malos respondedores, la reacción desmoplásica intermedia/inmadura se asoció con una peor supervivencia libre de recurrencia (p = 0,03). La quimioterapia adyuvante no mejoró significativamente la tasa de supervivencia sin recurrencia a 5 años para el grupo maduro (quimioterapia adyuvante vs. ninguna quimioterapia, 86,4% vs. 84,8%; p = 0,64), observándose tendencias peores en el grupo combinado intermedio/inmaduro (55,9% vs. 69,4%, respectivamente, p = 0,27).LIMITACIONES:Las limitaciones incluyen la naturaleza subjetiva de la evaluación de la reacción desmoplásica y el diseño retrospectivo del estudio.CONCLUSIONES:La reacción desmoplásica en muestras quirúrgicas después de la quimiorradioterapia se asocia con respuestas a la quimiorradioterapia y sirve como un factor pronóstico significativo en el cáncer rectal avanzado, particularmente para aquellos que responden mal a la quimiorradioterapia. (Traducción-Yesenia Rojas-Khalil ).

The Avocado Sign: A novel imaging marker for nodal staging in rectal cancer

OBJECTIVES

To evaluate the diagnostic performance of the Avocado Sign, a novel contrast-enhancement-based MR imaging marker, for prognostication of mesorectal lymph node spread in rectal cancer.

METHODS

This retrospective study included 106 patients with rectal cancer who underwent MRI examination. The Avocado Sign, defined as a hypointense core within an otherwise homogeneously hyperintense lymph node on contrast-enhanced T1-weighted images, was assessed. Of the cohort, 77 patients received neoadjuvant chemoradiotherapy followed by restaging MRI. Histopathological examination served as the reference standard. Diagnostic metrics were calculated and compared between subgroups using chi-square tests. Interobserver agreement was evaluated using Cohen's kappa.

RESULTS

The Avocado Sign demonstrated high diagnostic accuracy for predicting lymph node involvement, with an overall sensitivity of 88.7%, specificity of 84.9%, PPV of 85.5%, NPV of 88.2%, and accuracy of 86.8%. The area under the ROC curve was 0.87. Subgroup analysis revealed excellent performance in both patients undergoing surgery alone (sensitivity 100%, specificity 83.3%) and those receiving neoadjuvant therapy (sensitivity 84.2%, specificity 85.4%). Interobserver agreement was almost perfect (κ = 0.92).

CONCLUSION

The Avocado Sign is a promising imaging predictor for mesorectal lymph node status in rectal cancer. Its straightforward application, high reproducibility, and remarkable diagnostic accuracy underline its potential to refine MRI staging. However, further validation in larger, prospective multicenter studies is warranted to confirm these findings and assess their impact on clinical decision-making.

KEY POINTS

Question Can the Avocado Sign on contrast-enhanced MRI improve mesorectal lymph node staging in rectal cancer independently of classical morphological criteria? Findings The Avocado Sign demonstrated high sensitivity (88.7%) and specificity (84.9%) as a standalone marker for predicting mesorectal lymph node involvement. Clinical relevance Incorporating contrast-enhanced sequences and the Avocado Sign into MRI protocols enhances nodal staging accuracy in rectal cancer, potentially informing treatment decisions. Further validation is required to confirm its effectiveness and compare it with existing criteria.

Cost-Effectiveness of Total Neoadjuvant Therapy With Selective Nonoperative Management for Locally Advanced Rectal Cancer: Analysis of Data From the Organ Preservation for Rectal Adenocarcinoma Trial

PURPOSE

The clinical efficacy of total neoadjuvant therapy (TNT) followed by selective nonoperative management (NOM) for locally advanced rectal cancer (LARC) was examined in the Organ Preservation for Rectal Adenocarcinoma (OPRA) trial. We investigated the cost and quality-of-life implications of adopting this treatment approach.

METHODS

We analyzed clinical, cost, and quality-of-life outcomes for TNT with selective NOM in comparison with chemoradiotherapy (CRT)-surgery-adjuvant chemotherapy (standard of care [SOC]) using data from OPRA, prospective cohorts, and published studies. Cost-effectiveness was evaluated over varying willingness-to-pay thresholds, and sensitivity analyses evaluated cost-effectiveness for different surgical contexts and SOC variants as well as a 10-year time horizon.

RESULTS

SOC was dominated by TNT with selective NOM in the base case analysis. TNT in which CRT was followed by consolidation chemotherapy (CNCT) was the least costly at $89,712 in Medicare proportionate US dollars (MP$), followed by TNT in which induction chemotherapy was followed by CRT (INCT) at MP$90,259 and SOC at MP$98,755. INCT was the preferred strategy, with 4.56 quality-adjusted life years, followed by CNCT at 4.42 and SOC at 4.29. TNT with selective NOM dominated SOC in all sensitivity analyses except when SOC omitted adjuvant chemotherapy without an impact on disease-free survival. CNCT was more cost effective than SOC when the proportion of patients entering NOM after TNT was ≥22% or ≥43%, for SOC with and without adjuvant therapy, both well below the rates seen in OPRA.

CONCLUSION

TNT with selective NOM is cost effective. The cost-effectiveness of CNCT with NOM relative to SOC is dependent on CNCT being made available to a sufficiently large proportion of patients with LARC. Additional analyses are needed to validate these findings from a societal perspective and in the context of other emerging treatment paradigms for LARC.

Clinical Association of Negative Lymph Nodes With Adjuvant Chemotherapy in Patients With T3N0 Rectal Cancer

Background: The use of adjuvant chemotherapy in patients with stage T3N0 rectal cancer following total mesorectal excision (TME) is debated. This study is aimed at investigating the clinical significance of negative lymph node (NLN) counts in patients with T3N0 rectal cancer, particularly in relation to adjuvant chemotherapy. Methods: This retrospective analysis examined 311 patients with T3N0 rectal cancer who underwent radical resection at the Sixth Affiliated Hospital of Sun Yat-sen University between August 2014 and December 2021. The optimal cutoff for NLN counts was determined using receiver operating characteristic (ROC) curves. Clinicopathological characteristics and clinical outcomes were compared between the high and low NLN groups. Overall survival (OS) and disease-free survival (DFS) were used to evaluate the efficacy of adjuvant chemotherapy. Results: The optimal cutoff for NLNs was 21. Of the 311 patients, 141 were categorized into the high NLN group and 170 into the low NLN group. Patients with NLNs ≥ 21 had significantly better 5-year OS (99.3% vs. 88.2%, p < 0.05) and 5-year DFS (92.2% vs. 79.4%, p < 0.05) compared to those with low NLNs. Multivariate Cox analysis revealed that NLN count was an independent prognostic factor for OS (hazard ratio (HR) = 0.078, 95% confidence interval (CI): 0.011-0.582, p = 0.013) and DFS (HR = 0.417, 95% CI: 0.213-0.815, p = 0.011). Subgroup analysis indicated that adjuvant chemotherapy significantly improved OS (p < 0.05) and DFS (p < 0.05) in the low NLN group. Conclusion: NLN count is an independent prognostic factor in patients with T3N0 rectal cancer. Patients with low NLN counts (NLN < 21) may benefit from adjuvant chemotherapy.

Comparison of Standard Neoadjuvant Therapy and Total Neoadjuvant Therapy in Terms of Effectiveness in Patients Diagnosed with Locally Advanced Rectal Cancer

Background/Objectives: The study aimed to compare the treatment effectiveness of patients with locally advanced rectal cancer undergoing standard neoadjuvant therapy or total neoadjuvant therapy. It also sought to identify prognostic factors for disease-free survival and overall survival and parameters predictive of pathological complete response. Materials and Methods: A retrospective analysis was conducted on 239 patients diagnosed with locally advanced rectal cancer between 2016 and 2022 at several medical centers in Turkey. Clinical data, including neoadjuvant chemoradiotherapy types, chemotherapy regimens, surgical outcomes, and survival metrics, were collected. Statistical analyses included chi-square tests, Kaplan-Meier survival analysis, and Cox proportional hazard models to evaluate prognostic factors for disease-free survival and overall survival and logistic regression to identify predictors of pathological complete response. Results: Among 239 patients, 46.9% received total neoadjuvant therapy, while 53.1% underwent standard neoadjuvant therapy. Total neoadjuvant therapy was associated with a significantly higher pathological complete response rate (45.5% vs. 14.9% in standard neoadjuvant therapy; p < 0.001) and longer disease-free survival (median 124.2 vs. 72.4 months). The 3-year overall survival rate for all patients was 90.7%, and disease-free survival was 76.8%. Multivariate analysis identified pathological complete response (HR: 2.34), total neoadjuvant therapy (HR: 5.12), and type of surgery (HR: 8.12) as independent prognostic factors for disease-free survival, and pathological complete response and absence of lymphovascular invasion as independent prognostic factors for overall survival. Logistic regression analysis showed that total neoadjuvant therapy (OR: 4.40) and initial neoadjuvant chemotherapy (OR: 2.02) were independent predictors of achieving pathological complete response. Conclusions: Total neoadjuvant therapy significantly improves pathological complete response rates, disease-free survival, and overall survival in patients with locally advanced rectal cancer compared to standard neoadjuvant therapy. Total neoadjuvant therapy and achieving pathological complete response are strong independent prognostic factors for both disease-free survival and overall survival, suggesting that a more intensive neoadjuvant approach may lead to better outcomes in locally advanced rectal cancer. The increased pathological complete responses rate with total neoadjuvant therapy has created an opportunity for the development of new treatment modalities and the advancement of non-surgical management strategies in the future.

Prognosis and quality of life in patients with locally advanced rectal cancer after abdominoperineal resection in the CAO/ARO/AIO-04 randomized phase 3 trial

Low anterior resection (LAR) and abdominoperineal resection (APR) are the two main surgical procedures after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. APR is associated with poorer prognosis; however existing data do not consider intensified CRT (5-Fluorouracil (5-FU)/Oxaliplatin + radiation) protocols. Clinicopathological data of patients treated with APR and LAR from the CAO/ARO/AIO-04 trial were analysed in terms of prognostic parameters and quality of life (QoL). Based on higher response rate after intensified CRT, subgroup analyses were performed. Data from n = 1173 patients were assessed. APR after preoperative CRT was associated with a significantly worse overall survival (p = 0.0056), disease-free survival (p < 0.0001) and local recurrence rate (p = 0.0047). Clinicopathological data including clinical T stage (p < 0.000001), grading (p = 0.0038), postoperative lymph node (LN) positivity (p = 0.013), and number of positive LN (p = 0.0049) significantly differed between procedures and showed higher values in APR patients. The quality of total mesorectal excision (TME) was significantly better (p < 0.0001) and complete resection rates were higher (p = 0.0022) in LAR compared to APR patients. Subgroup analyses showed worse LR rates in APR patients after standard CRT (5-FU mono and radiation) but not after intensified CRT. After 3 years, role functioning (p = 0.019) and physical functioning (p = 0.001) had a slightly poorer outcome in APR patients. The poorer prognosis of patients undergoing APR for locally advanced rectal cancer may be explained by clinicopathological characteristics. Intensified CRT may compensate for the higher risk of LR after APR in patients with worse TME quality. QoL in APR patients was comparable to LAR patients.

Analysis of clinical and pathological prognostic factors of survival in rectal adenocarcinoma treated with preoperative radiochemotherapy

PURPOSE

To identify the prognostic variables related to the survival of patients operated on for adenocarcinoma of the rectum who underwent preoperative radiochemotherapy (RCT).

METHODS

We studied 70 patients from the Discipline of Surgical Gastroenterology at Escola Paulista de Medicina from 2000 to 2019, with rectal cancer located up to 10 cm from the anal verge and with stages II or III, submitted to preoperative RCT and curative surgery (R0) and with follow-up of at least 12 months. Clinical restaging was performed four to six weeks after the end of neoadjuvant treatment to characterize the degree of clinical tumor regression. Surgery by laparotomy or videolaparoscopy was performed six to 12 weeks after RCT. Primary endpoint were: overall survival (OS), disease-free survival (DFS), metastasis-free survival (MSS), and neoplasm-specific survival (SEN). These were compared with gender, age, carcinoembryonic antigen (CEA) dosage, distance from the tumor to the anal verge, radiation dose, radiotherapy-surgery interval, clinical regression, type of surgery, pT and pN TNM stage tumor, number of nodes, circumferential resection margin, and complete pathological response. Survival was assessed by Kaplan-Meier curves. Univariate and multivariate Cox analyses were calculated to identify factors associated with survival outcomes.

RESULTS

The mean follow-up time was 62 months. The pathological complete response rate was 18.6%. Univariate cox regression showed a significant relationship of CEA equal to or greater than 4 ng/mL with DFS and MFS, pT3/pT4 staging with DFS, MFS and SEN, pN1/N2 with DFS, MFS and SEN and stages II and III with DFS and MFS. Multivariate regression found that CEA, pT, and pN staging are independent prognostic factors for DFS, MFS, and SEN.

CONCLUSION

Carcinoembryonic antigen level prior to radiotherapy, pT staging and pN staging were independent prognostic factors for survival in patients with rectal adenocarcinoma who are treated with preoperative radiochemotherapy.

Radioresistance in rectal cancer: can nanoparticles turn the tide?

Rectal cancer accounts for over 35% of the worldwide colorectal cancer burden representing a distinctive subset of cancers from those arising in the colon. Colorectal cancers exhibit a continuum of traits that differ with their location in the large intestine. Due to anatomical and molecular differences, rectal cancer is treated differently from colon cancer, with neoadjuvant chemoradiotherapy playing a pivotal role in the control of the locally advanced disease. However, radioresistance remains a major obstacle often correlated with poor prognosis. Multifunctional nanomedicines offer a promising approach to improve radiotherapy response rates, as well as to increase the intratumoral concentration of chemotherapeutic agents, such as 5-Fluorouracil. Here, we revise the main molecular differences between rectal and colon tumors, exploring the complex orchestration beyond rectal cancer radioresistance and the most promising nanomedicines reported in the literature to improve neoadjuvant therapy response rates.

A multifunctional metal-based nanozyme for CT/PTI-guided photothermal/starvation/chemodynamic therapy against colon tumor

Colon cancer is a major global health threat. Early detection and treatment are crucial for improving survival rates. Conventional methods, like colonoscopies and CT scans, have limitations, emphasizing the need for innovative strategies. This study introduces an IP6-coated nanozyme, CeO2@Au@IP6 (CeAIP), for diagnosing and treating colon cancer. IP6 inhibits cancer cell growth and improves the stability and dispersibility of the nanozyme. The peroxidase activity of cerium dioxide (CeO2) alleviates tumor hypoxia and generates toxic hydroxyl radicals. Gold nanoparticles (Au NPs) utilize the surface plasmon resonance (SPR) effect for photothermal therapy (PTT) and exhibit peroxidase- and glucose oxidase-like activities. This combination enhances the therapeutic effects of PTT, starvation therapy (ST), and chemodynamic therapy (CDT), while also enabling dual-modality CT/PT imaging. CeAIP NPs effectively treat colon cancer with PTT, ST, and CDT under 808 nm near-infrared laser irradiation. This integrated nanozyme-based approach offers hope for early detection and treatment of colon cancer, potentially improving cure rates.

Organ Function Preservation in Locally Advanced Low Rectal Cancer Through Total Neoadjuvant Therapy: A Case Report and Literature Review

Locally advanced rectal cancer (LARC) is a common malignancy that is often managed with neoadjuvant radiotherapy to downstage the tumor and increase the rate of complete response. Recent evidence suggests that total neoadjuvant therapy (TNT) may further improve complete response rates and overall survival compared to conventional treatment methods. This case report describes a 61-year-old male patient with LARC who achieved a clinical complete response following TNT. The treatment regimen followed the CinClare study protocol, which included radiotherapy targeting both the rectum and regional lymph nodes, in combination with chemotherapy consisting of irinotecan and capecitabine. After concurrent chemoradiotherapy, the patient underwent six additional cycles of consolidation chemotherapy, leading to a near-complete clinical response. This case demonstrates the potential effectiveness of a high-intensity, dose-dense regimen involving synchronous radiotherapy followed by a six-cycle consolidation chemotherapy course aimed at optimizing organ preservation. This approach highlights a novel model for enhancing organ preservation in patients with low-grade LARC.

Margin matters: analyzing the impact of circumferential margin involvement on survival and recurrence after incomplete total mesorectal excision for rectal cancer

BACKGROUND

Incomplete mesorectal excision during rectal cancer surgery often leads to positive circumferential margins, with uncertain prognostic impacts. This study examines whether negative margins can mitigate the poorer prognosis typically associated with incomplete total mesorectal excision (TME) in rectal cancer surgery, thus potentially challenging the prevailing emphasis on complete mesorectal excision.

PATIENTS AND METHODS

A retrospective analysis was conducted on patients who underwent proctectomy for rectal adenocarcinoma with incomplete TME at a single center from 2010 to 2022. Patients were stratified by margin status as determined by pathologic analysis into three groups: involved, not involved with closest margin distance ≤ 2 mm, and not involved with closest margin distance > 2 mm. Outcomes included recurrence and survival. Effects of neoadjuvant therapy protocols on margin status were also assessed.

RESULTS

From 2010 to 2022, 7941 patients underwent proctectomy for rectal cancer, with 236 (3%) having incomplete TME. The median age of these patients was 64 years, and 63% were male. Overall, margin involvement was observed in 54 (23%) patients. The median tumor size was 3.05 cm (interquartile range (IQR): 2-6) for the whole group. Involved margins (23.2%) had reduced overall survival (60.5 months versus 87.3 months, p < 0.001), increased local recurrence (20.4% versus 9.4%, p = 0.024), and lower disease-free survival (45.2 versus 58.9 months, p = 0.006) versus uninvolved margins. Margin involvement was prognostic for decreased survival even after adjusting for confounders (p < 0.05). Among uninvolved margins, distance (> 2 mm versus ≤ 2 mm) did not affect outcomes. Total neoadjuvant therapy (versus standard chemoradiation) was associated with lower involved margins (p = 0.007).

CONCLUSIONS

Positive margins retain negative prognostic impact with incomplete TME. Optimization of surgical resection remains vital. Total neoadjuvant therapy was associated with a lower rate of margin involvement.

Who is a candidate at the initial presentation? Prediction of positive lateral lymph node and survival after dissection

Metastatic lateral pelvic lymph node (LPN) in rectal cancer has a significant clinical impact on the prognosis and treatment strategies. But there are still debates regarding prediction of lateral pelvic lymph node metastasis and its oncological impact. This review explores the evidence for predicting lateral pelvic lymph node metastasis and survival in locally advanced rectal cancer. Until now many studies have reported that magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) are considered as essential tools for predicting metastatic LPN, with MRI-based size criteria, particularly the short-axis diameter of LPN. But several studies have reported that the addition of tumor location or artificial intelligence (AI) can further enhance diagnostic accuracy. Western practices focus more on neoadjuvant chemoradiation (nCRT), while Eastern countries focus more on lateral pelvic lymph node dissection (LPND). LPND has been shown to reduce lateral local recurrence (LLR) rates compared to total mesorectal excision (TME) alone, particularly in patients with enlarged LPNs, but its impact on overall survival is uncertain. The decision to perform LPND should be individualized according to LPN size and response to nCRT; and through selective LPND based on those criteria, patients could achieve a balance between the benefit of local control and the risk of surgical complications from LPND, such as sexual and urinary dysfunction.

Assembly Regulates Gamma Radiation Polymerization of Polytelluoxane

Regulating chemical drug's responsiveness to gamma radiation is crucial for achieving better therapeutic effects in cancer treatment. Most research focused on thermodynamic chemical structure design, while little attention was paid to kinetic regulate strategy, which possesses greater universality and security. In this study, we achieved a kinetic-based regulate strategy of gamma radiation reaction, through the construction of microphase environment during polymerization of polytelluoxane (PTeO). We designed hydrophobic segments forming large compound micelles (LCMs) assembly to create kinetically favorable higher concentration for radiation-induced reaction. It exhibited a > ten times higher responsiveness and, as far as we know, merely required a minimum dosage of 5 Gy for polymerization to occur. What's more, by taking advantages of the assembly change with Te-O hydrophilic segments and gamma radiation, polymerization became milder with lower polydispersity than previous methods. Such kinetic-based regulate strategy could offer a novel perspective on the design of radiation-responsive chemoradiotherapy and other radiation-induced chemical process.

Impact of adjuvant chemotherapy on survival in ypT0-2 N0 rectal cancer

PURPOSE

The role of adjuvant chemotherapy in rectal cancer patients downstaged to ypT0-2 N0 after neoadjuvant chemoradiotherapy (CRT), and surgery is still debated. This study investigates the impact of adjuvant chemotherapy on survival outcomes in this patient population.

METHODS

This retrospective study analyzed hospital records of rectal cancer cases from Shefa Al Orman Cancer Hospital between January 2016 and December 2020, focusing on patients downstaged to ypT0-2 N0 after neoadjuvant CRT and surgery. Patients were divided into two groups based on whether they received adjuvant chemotherapy. Baseline characteristics, DFS, and OS were compared, and survival factors were analyzed using univariate and multivariate Cox regression.

RESULTS

Eighty-five patients met the inclusion criteria; 55 received adjuvant chemotherapy, and 30 did not. The median age was 52, but those receiving adjuvant therapy were younger (47 vs. 60 years, P = 0.006). No significant differences were observed in sex, tumor location, or pathology between groups. Although adjuvant chemotherapy showed a trend toward better 3-year DFS (89.5% vs. 81.9%, P = 0.153) and OS (88.1% vs. 84.6%, P = 0.654), these differences were not statistically significant. Univariate and multivariate analyses confirmed no significant effect of adjuvant chemotherapy on DFS or OS, nor were any other variables significantly associated with survival.

CONCLUSION

Adjuvant chemotherapy did not significantly improve DFS or OS in rectal cancer patients downstaged to ypT0-2 N0 following neoadjuvant CRT and surgery. Further studies are needed to define the role of adjuvant therapy in this group.

Advantages of Robotic Total Mesorectal Excision With Partial Prostatectomy Compared With Open Surgery for Rectal Cancer: A Single-Center Retrospective Cohort Study

AIM

Robotic total mesorectal excision (TME) with resection of adjacent organs has been increasingly used for locally advanced rectal cancer; however, few studies have focused on robotic TME with partial prostatectomy. Therefore, this study aimed to demonstrate the advantages of robotic TME with partial prostatectomy compared with open surgery for rectal cancer.

METHOD

This retrospective cohort study examined consecutive patients with rectal cancer who underwent robotic or open TME with partial prostatectomy at a high-volume center in Japan from April 2003 to March 2022. The patients were divided into robotic (n = 14) and open (n = 11) surgery groups. The short- and long-term outcomes of these patients were compared.

RESULTS

More transabdominal partial prostatectomies were performed in the robotic surgery group than in the open surgery group (71.4% vs. 9.1%, p = 0.001). Moreover, sphincter-preserving surgery was performed in 35.7% of patients in the robotic surgery group. The robotic surgery group had shorter operative times (401 min vs. 435 min, p = 0.047), less blood loss (56 mL vs. 484 mL, p < 0.001), lower complication rates (28.6% vs. 72.7%, p = 0.047), and shorter postoperative hospital stays (8 days vs. 18 days, p < 0.001) than the open surgery group. No significant differences were observed in the positive radial margin rate (7.1% vs. 9.1%, p = 1.000) or long-term outcomes between the two groups.

CONCLUSION

Compared with open surgery, robotic TME with partial prostatectomy facilitates transabdominal partial prostatectomy, resulting in more sphincter-preserving surgeries and better short-term outcomes.

Outcomes of Distal Rectal Cancer Patients Who Did Not Qualify for Watch-and-Wait: Comparison of Intersphincteric Resection Versus Abdominoperineal Resection

INTRODUCTION

Total mesorectal excision (TME) with intersphincteric resection and handsewn coloanal anastomosis (ISR-CAA) has been shown to be oncologically safe in patients with distal rectal cancer treated with preoperative chemoradiation. The introduction of the watch-and-wait (WW) strategy for rectal cancer patients with a clinical complete response to neoadjuvant therapy is changing the profile of patients undergoing TME surgery immediately following neoadjuvant treatment. The outcomes of ISR-CAA for patients with locally advanced rectal cancers not qualifying for WW have not been investigated.

METHODS

We conducted a retrospective analysis comparing the outcomes of ISR-CAA and abdominoperineal resection (APR) in patients with distal rectal cancer treated with neoadjuvant therapy and not qualifying for WW, at a comprehensive cancer center with an established WW program. The primary outcome was local recurrence-free survival.

RESULTS

Sixty-seven patients had ISR-CAA and 79 had APR. Median follow-up was 61.1 months. The two groups were similar in sex, tumor stage, grade, and distance from the anal verge, but patients in the APR group were older on average. An R0 resection was achieved in 94% of ISR-CAA patients and 91% of APR patients. Patients in the ISR-CAA group had a lower 5-year rate of local recurrence-free survival (79% vs. 93%; p = 0.038) compared with the APR group; however, 5-year disease-free survival did not differ significantly between groups (67% for ISR-CAA and 64% for APR; p = 0.19).

CONCLUSIONS

The local recurrence rate after ISR-CAA may be higher than after APR for patients without a clinical complete response to neoadjuvant therapy requiring TME surgery.

Early Outcomes of Preoperative Short Course Radiotherapy With Simultaneous Integrated Boost and Response-adapted Chemotherapy for Advanced Rectal Cancer

BACKGROUND AND PURPOSE

Limited evidence exists for dose escalation in neoadjuvant short course radiotherapy (SCRT) for rectal cancer. With enhanced imaging and radiotherapy techniques over the past decades along with the valuable endpoint of pathological complete response (pCR), we believe SCRT with simultaneous integrated boost could potentially provide deeper pathological responses and improve local control.

METHODS AND MATERIALS

Between January 2020 and December 2022, locoregional-advanced rectal cancer patients that were treated with neoadjuvant SCRT with simultaneous integrated boost up to 5.5-6Gy per fraction with five daily fractions followed by response-adapted chemotherapy was retrospectively reviewed. The pCR rates, R0 resection rates, tumor downstaging, toxicities, and early pattern of recurrence are reported.

RESULTS

Among the 76 patients, 67 (88%) were able to undergo curative intent surgery. R0 resection was achieved in 99% (n = 66) of patients with pCR rates of 28% (n = 19). Forty-six percent (n = 31) of patients had significant pathological downstaging (ypT2N0) and 55% (n = 37) of patients had both T and N downstaging. Most common grade 3 or above radiotherapy-related side-effects were proctitis, rectal pain, and dermatitis found in 5% (n = 4), 3% (n = 2) and 3% (n = 2) of patients, respectively. Grade 3 or above surgical complications were observed in 15% (n = 10) of patients. There were no treatment-related deaths. With a median follow-up of 27 months, only 6% (n = 4) had local recurrence after surgery.

CONCLUSIONS

Neoadjuvant short course radiotherapy with simultaneous boost for rectal cancer is feasible with no added toxicities. Patients who underwent surgery achieve a high R0 resection and pCR rates. Early data suggest low rates of locoregional recurrence. Further follow-up and research is needed to validate and optimize the dose, method, and schedule of dose escalation.

Comparison of robotic and laparoscopic approaches in short- and long-term outcomes of lateral pelvic lymph node dissection for advanced rectal cancer: a Japanese multicenter study

BACKGROUND

Lateral pelvic lymph node dissection (LPND) is a challenging surgical technique with complex anatomy and narrow pelvic manipulation. The outcomes of robotic and laparoscopic surgery for LPND are still unclear.

METHODS

We retrospectively reviewed 169 consecutive patients who underwent rectal cancer surgery with LPND between 2016 and 2023. Patients were divided into two groups according to whether LPND was performed by robotic surgery (R group, n = 40) or laparoscopic surgery (L group, n = 129). Clinicopathological feature and outcomes were compared between groups.

RESULTS

Frequency of surgery with combined resection of adjacent structures (5.0% vs. 19.4%, p = 0.023), frequency of patients with distant metastasis (5.0% vs. 19.4%, p = 0.028), and estimated blood loss from bilateral LPND (74 mL vs. 132 mL, p = 0.013) were all lower in the R group than in the L group. Type of surgical approach did not correlate with postoperative complications. Median follow-up was 31.0 months (range, 1.0-69.0 months). No patients in the R group experienced local recurrence, compared to 4.6% in the L group. Multivariate analysis revealed laparoscopic surgery (odds ratio 3.687, 95% confidence interval 1.505-6.033; p = 0.004) as an independent predictor of poor relapse-free survival.

CONCLUSIONS

Robotic surgery for LPND appears to have good prognostic value in some, but not all, oncologic cases. However, large prospective studies are desirable to validate these findings.

Nonoperative management of rectal cancer

The management of locally advanced rectal cancer has changed drastically in the last few decades due to improved surgical techniques, development of multimodal treatment approaches and the introduction of a watch and wait (WW) strategy. For patients with a complete response to neoadjuvant treatment, WW offers an opportunity to avoid the morbidity associated with total mesorectal excision in favor of organ preservation. Despite growing interest in WW, prospective data on the safety and efficacy of nonoperative management are limited. Challenges remain in optimizing multimodal treatment regimens to maximize tumor regression and in improving the accuracy of patient selection for WW. This review summarizes the history of treatment for rectal cancer and the development of a WW strategy. It also provides an overview of clinical considerations for patients interested in nonoperative management, including restaging strategies, WW selection criteria, surveillance protocols and long-term oncologic outcomes.

Lateral lymph node metastasis without mesenteric lymph node involvement in middle-low rectal cancer: Results of a multicentre lateral node collaborative group study in China

BACKGROUND

Characteristics and prognoses of lateral lymph node (LLN) metastasis but not mesenteric lymph node (LN) metastasis are poorly understood. This study explored patterns of mesenteric and LLN metastases in rectal cancer patients.

METHOD

This retrospective, multicentre study was conducted at three institutions and included patients who underwent total mesorectal excision (TME) with lateral lymph node dissection (LLND) for rectal cancer (n = 271).

RESULTS

Among the patients with LLN metastases, 210 patients (77.5 %) with clinical stage T3-4 disease and 157 patients (57.9 %) with clinical stage N1-N2 disease underwent TME as well as LLND. The prognoses of patients with metastasis confined to LLNs were significantly better than those of patients with both mesenteric and LLN metastases (3-year overall survival: 85.0 % vs. 51.0 %, p = 0.005; 3-year disease-free survival: 75.0 % vs. 26.5 %, p = 0.003) and were similar to those of patients with metastasis confined to mesenteric LNs (3-year overall survival: 85.0 % vs. 83.8 %, p = 0.607; 3-year disease-free survival 75.0 % vs. 68.8 %, p = 0.717). Patients with metastases confined to LLN had a lower proportion of poor histological types (20.0 % vs. 65.3 %, p = 0.002), lymphatic invasion (20.0 % vs. 59.2 %, p = 0.036) and number of LLN metastases (1.6 vs 2.7, p = 0.004), and all metastases were confined to the internal iliac or obturator region (100.0 % vs. 77.6 %, p = 0.008) compared to patients with both mesenteric and LLN metastasis.

CONCLUSIONS

Approximately a quarter of patients with rectal cancer have LLN metastases but no mesenteric LN metastases. These patients have favourable pathological features and prognoses and can be managed and treated for mesenteric LN metastasis.

Neoadjuvant immunotherapy for dMMR and pMMR colorectal cancers: therapeutic strategies and putative biomarkers of response

Approximately 15% of locally advanced colorectal cancers (CRC) have DNA mismatch repair deficiency (dMMR), resulting in high microsatellite instability and a high tumour mutational burden. These cancers are frequently sensitive to therapy with immune-checkpoint inhibitors (ICIs) in the metastatic setting. This sensitivity seems to be even more pronounced in locally advanced disease, and organ preservation has become a realistic aim in ongoing clinical trials involving patients with dMMR rectal cancer. By contrast, metastatic CRCs with proficient DNA mismatch repair (pMMR) are generally resistant to ICIs, although a proportion of locally advanced pMMR tumours seem to have a high degree of sensitivity to ICIs. In this Review, we describe the current and emerging clinical evidence supporting the use of neoadjuvant ICIs in patients with dMMR and pMMR CRC, and the potential advantages (based on a biological rationale) of such an approach. We discuss how neoadjuvant 'window-of-opportunity' trials are being leveraged to progress biomarker discovery and we provide an overview of potential predictive biomarkers of response to ICIs, exploring the challenges faced when evaluating such biomarkers in biopsy-derived samples. Lastly, we describe how these discoveries might be used to drive a rational approach to trialling novel immunotherapeutic strategies in patients with pMMR CRC, with the ultimate aim of disease eradication and the generation of long-term immunosurveillance.

Effects of Adjuvant Chemotherapy on Oncologic Outcomes in Patients With Stage ⅡA Rectal Cancer Above the Peritoneal Reflection Who Did Not Undergo Preoperative Chemoradiotherapy

PURPOSE

This study aimed to evaluate the effects of adjuvant chemotherapy (AC) on oncologic outcomes for patients with stage IIA upper rectal cancer and to investigate whether AC is associated with improved survival outcomes.

METHODS

This retrospective study comprised 432 patients with rectal cancer above the peritoneal reflection who had undergone curative resection without preoperative chemoradiotherapy between 2008 and 2016. This study cohort was divided according to whether AC was received (AC group) or not (no-AC group). Risk factors included obstruction, perforation, poorly-differentiated tumor, lympho-vascular invasion, perineural invasion, resection margin involvement, and < 12 lymph nodes harvested.

RESULTS

Among the 432 patients, 279 (64.6%) had received AC. The AC group had significantly higher 5-year overall survival (OS) rates than those of the no-AC group (93.2% vs. 84.6%, P = .001). Among patients with ≥ 1 risk factors, the AC group (n = 123) had significantly higher rates of 5-year recurrence-free survival (RFS) (81.6% vs. 64.1%, P = .01) and 5-year OS (88.8% vs. 69.0%, P = .001) than those of the no-AC group (n = 59). No significant difference in survival outcomes was observed between the 2 groups in patients aged > 65 years.

CONCLUSION

AC was significantly associated with better 5-year RFS and 5-year OS rates in patients with stage IIA rectal cancer above peritoneal reflection who did not receive preoperative chemoradiotherapy, especially in those with ≥ 1 risk factors.

Neoadjuvant chemoradiotherapy is associated with prolonged relapse free survival in patient with MRI-detected extramural vascular invasion (mrEMVI) positive rectal cancer: A multicenter retrospective cohort study in Japan

PURPOSE

Neoadjuvant chemoradiotherapy (nCRT) is employed for the local control of locally advanced rectal cancer; however, its prognostic impact is limited and often impairs pelvic organ function. Therefore, careful patient selection is essential. This study aimed to investigate the impact of nCRT on relapse-free survival (RFS) by stratifying patients according to MRI detected circumferential resection margin (mrCRM) or extramural vascular invasion (mrEMVI), as the ability of MRI findings to identify patients who will have beneficial outcomes from nCRT is uncertain.

METHODS

We retrospectively analyzed patients with clinical stage II-III lower rectal cancer who underwent surgical resection with or without nCRT between 2010 and 2011 at 69 hospitals in Japan. The impact of nCRT on RFS was evaluated using multivariable Cox regression models in the entire cohort and in subgroups stratified by mrCRM or mrEMVI status.

RESULTS

In the entire cohort (nCRT, n = 172; surgery alone, n = 503), nCRT showed a trend toward improved RFS, although the difference was not statistically significant (HR, 0.74; 95 % CI, 0.54-1.03; P = 0.074). Among mrCRM-negative and mrEMVI-negative patients, there were no significant differences in RFS between the nCRT and surgery-alone groups. Among mrCRM-positive patients, nCRT tended to improve the RFS (HR, 0.70; 95 % CI, 0.46-1.06; P = 0.089). Among mrEMVI-positive patients, nCRT significantly prolonged the RFS (HR, 0.62; 95 % CI, 0.38-1.00; P = 0.048).

CONCLUSIONS

Compared to surgery alone, nCRT did not significantly improve RFS in the overall population but significantly improved RFS in mrEMVI-positive patients.

Prognostic impact of lateral sentinel lymph node biopsy using indocyanine green on oncological outcomes for clinical stage II/III lower rectal cancer without suspected lateral lymph node metastasis

PURPOSE

Sentinel lymph node biopsy (SLNB) can detect occult nodal metastasis. We have previously reported the safety and feasibility of indocyanine green (ICG)-guided SLNB for clinical stage II/III lower rectal cancer (RC). However, little is known about the influence of lateral pelvic SLNB using ICG on oncological outcomes. The present study aimed to evaluate the prognostic impact of lateral pelvic SLNB on oncological outcomes compared with prophylactic lateral lymph node dissection (LLND).

METHODS

Participants comprised consecutive patients with clinical stage II/III lower RC who underwent lateral pelvic SLNB or prophylactic LLND (Non-SLNB) between January 2010 and December 2020. The primary outcome measure was the 5-year cumulative incidence of local recurrence (LR). Secondary endpoints included cancer-specific survival (CSS), overall survival (OS), recurrence-free survival (RFS), local recurrence-free survival (LRFS), and distant recurrence-free survival (DRFS).

RESULTS

Among the 150 eligible patients included, 79 patients underwent lateral pelvic SLNB. Of those 79 patients, 4 patients who were SLNB-positive underwent LLND. LLND was omitted for the 75 patients who were SLNB-negative. Median follow-up was 61.0 months (range, 1.3-143.2 months). The overall recurrence rate was 30.7% (46 patients), with LR in 12.0% (18 patients). LR comprised lateral lymph node recurrence in 2.6% and central pelvic recurrence in 9.4%. No significant differences were seen between groups in terms of the frequency of LR or in CSS, OS, RFS, LRFS, or DRFS.

CONCLUSION

Oncological outcomes were not different between the SLNB and Non-SLNB groups. ICG-guided SLNB appears promising as a method for determining indications for LLND.

Evaluating complete response rates and predictors in total neoadjuvant therapy for rectal cancer

BACKGROUND

There is a paradigm shift in the management of locally advanced rectal cancer (LARC) from conventional neoadjuvant treatment to total neoadjuvant therapy (TNT). Despite its growing acceptance, there are limited studies that have examined its effects on disease presentation. In addition, it is important to determine the factors that play a role in complete response (CR). Our previous data from 119 patients revealed that the CR rate was 37%, and low rectal tumors and the absence of extramural vascular invasion (EMVI) were predictors of CR. Unfortunately, there continues to be a lack of data, and reliable markers are still needed to consistently identify the best respondents. Therefore, this study aimed to determine the factors associated with CR. Moreover, this study hypothesized that both predictive factors and the CR ratio might evolve over time because of the growing patient population.

METHODS

This retrospective study included patients who completed TNT for LARC at our tertiary care center between 2015 and 2022. The primary outcome was to determine the predictors of CR. The secondary outcomes were the 2-year disease-free survival (DFS) rate and overall survival (OS) rate. CR consists of patients who sustained clinical CR (cCR) for at least 12 months under watch and wait or had pathologic CR (pCR) after surgery.

RESULTS

Of 339 patients with LARC, 208 (61.3%) successfully completed TNT. Among 208 patients, 57 (27.4%) achieved cCR, and 166 (80.0%) sustained cCR without tumor regrowth after 1 year. The remaining 151 patients (72.6%) underwent surgery, and 42 patients had pCR. The final CR rate was 42.3%. The median age of the patients was 56 years (IQR, 49-66). Moreover, 132 participants (63.5%) were male, whereas 76 participants (36.5%) were female. The median tumor size was 4.95 cm (IQR, 3.60-6.43), with most tumors in the low rectum (119 [57.2%]). Based on the MRI findings, the mesorectal facia (MRF) involvement rate was 25.0% (n = 52), and EMVI was observed in 43 patients (20.7%). Low rectal tumors, the absence of MRF involvement, and the absence of EMVI were predictors of CR. With a median follow-up of 24.7 months, 2-year DFS and OS were significantly higher among patients with CR than among patients with incomplete response (91.3% vs 71.0% [P < .01] and 98.8% vs 90.2% [P = .03], respectively).

CONCLUSION

An increasing CR rate was observed in our updated dataset compared with that in our previous study. In addition to previously identified predictors, low tumor location, and the absence of EMVI, the absence of MRF involvement was determined as a predictor of CR. Our findings offer valuable insights into clinical practice and help clinicians set clear expectations when counseling patients.

Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy for initially unresectable locally advanced colon cancer: short-term outcomes of an open-label, single-centre, randomised, controlled, phase 3 trial

Background

Neoadjuvant chemotherapy (NACT) is commonly used to downstage the tumor in locally advanced colon cancer (LACC) and improve the R0 resection rate. Neoadjuvant chemoradiotherapy (NACRT) is the standard treatment for locally advanced rectal and esophageal cancers, but its benefits in LACC remain poorly understood. This study aimed to compare the effects and safety of NACRT and NACT on R0 resection and survival rates in initially unresectable LACC.

Methods

This was an open-label, single-center, randomized, controlled trial conducted between May 11, 2019 and May 30, 2022. Forty-five patients with initially unresectable LACC were randomly allocated to the NACT (control, n = 20) or NACRT (research, n = 25) group. The NACT group received XELOX (oxaliplatin 100-130 mg/m2, qd, d1, every 3 weeks; and capecitabine 1000 mg/m2, bid, d1-d14, every 3 weeks) for 4 cycles. The NACRT group, in addition to chemotherapy, received daily irradiation (GTV 45-50 Gy/25 F; CTV 42.5-45 Gy/25 F). Surgery was scheduled 6-12 weeks after neoadjuvant treatment and adjuvant chemotherapy was administered if the patient developed resectable LACC. The primary endpoint was the 5-year overall survival (OS) rate. The secondary outcomes included the 3-year progression-free survival (PFS) and R0 resection rates. This study was registered with ClinicalTrials.gov (NCT03970694).

Findings

In short-term outcome analysis, NACRT significantly improved the R0 resection rate (80% for NACRT vs. 20% for NACT, P < 0.001). The NACRT and NACT groups had a 3-year OS of 87.6% and 75% (P = 0.037) and a 3-year PFS of 76% and 45% (P = 0.049), respectively. The 5-year OS was not reached. In the NACRT group, no local or regional recurrence was observed in patients who underwent surgery during the follow-up period, compared to two patients in the NACT group. Both NACT and NACRT were well tolerated, with no significant differences in severe adverse events. The most commonly observed grade 3-4 AE was myelosuppression (39% for NACRT and 47% for NACT, P = 0.609). No grade 5 AEs were observed between the two groups.

Interpretation

Adding radiation to NACT increased the R0 resection rate, prolonged the PFS, and potentially improved OS in selected patients with initially unresectable LACC. The trial findings indicate that this approach is safe, feasible, and may confer a survival benefit.

Funding

This study was supported by grants from the National Natural Science Foundation of China (82373213 to Dr Gao, 82202952 to Dr Wang); and the Natural Science Foundation of Guangdong Province (2023A1515010290 to Dr Chang). Funding sources were not involved in the study design, data collection, analysis and interpretation, writing of the report, or decision to submit the article for publication.

Neoadjuvant Treatment in Rectal Cancer

A major advance in rectal cancer was the evidence supporting short-course radiotherapy and long-course chemoradiotherapy. Both have been shown to improve local outcomes. Total neoadjuvant therapy (TNT) is the new kid on the block that provides further benefit of improving local responses as well as reducing systemic relapses, thus increasing overall survival. Details of the four key TNT trials are discussed. They pave the way for nonoperative management for patients who achieve clinical complete responses.

Pathologic Outcomes of Short-Course and Long-Course Radiotherapy for Locally Advanced Rectal Cancers Treated With Total Neoadjuvant Therapy

INTRODUCTION

Total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is now the standard of care. Randomized trials suggest the use of short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are oncologically equivalent.

OBJECTIVE

To describe pathologic outcomes after surgical resections of patients receiving SCRT versus LCRT as part of TNT for LARC.

PARTICIPANTS

All patients with LARC treated at a single tertiary hospital who underwent proctectomy after completing TNT were included. Patients were excluded if adequate details of TNT were not available in the electronic medical record.

RESULTS

A total of 53 patients with LARC were included. Thirty-nine patients (73.5%) received LCRT and 14 (26.4%) received SCRT. Forty-nine patients (92.5%) were clinical stage III (cN1-2) prior to treatment. The average lymph node yield after proctectomy was 20.9 for SCRT and 17.0 for LCRT (P = .075). Of the 49 patients with clinically positive nodes before treatment, 76.9% of those who received SCRT and 72.2% of those who received LCRT achieved pN0 disease after TNT. Additionally, there were no significant differences in rates of pathologic complete response between patients who received SCRT and LCRT, 7.1% and 12.8%, respectively (P = .565).

CONCLUSION

Pathologic outcomes of patients with LARC treated with SCRT or LCRT, as part of TNT, may be similar. Further prospective trials are needed to assess long-term clinical outcomes and to determine best treatment protocols.

Pathologic Complete Response, Total Neoadjuvant Therapy and the Survival Paradox in Locally Advanced Rectal Cancer

BACKGROUND

Pathologic complete response (pCR) after preoperative chemoradiation (nCRT) correlates with improved overall survival for patients with locally advanced rectal cancers (LARCs). Escalation protocols including total neoadjuvant therapy (TNT), which delivers multi-agent chemotherapy and chemoradiation before surgery, are associated with increased complete response rates. However, TNT is not associated with improved overall survival. The authors hypothesized that the route to pCR may be an important predictor of oncologic outcome.

METHODS

Adults with LARC between 2006 and 2017 were identified in the National Cancer Database. The cohort was limited to those who received neoadjuvant radiation (45-70 Gy) and underwent proctectomy.

RESULTS

Of 25,880 patients, 16 % received TNT and 84 % had nCRT followed by either multi-agent (27 %), single-agent (14 %), or no adjuvant chemotherapy (44 %). Overall, 18 % achieved pCR, with higher rates in the TNT cohort than in the nCRT (18 %) or multi-agent (14 %) chemotherapy cohorts. With control for covariates, the OS in the pCR cohort was similar for the patients that received single-agent therapy and those that received multi-agent adjuvant therapy, and superior to the TNT and no adjuvant therapy cohorts. Conversely, among the patients who did not achieve pCR, those who received single-agent chemotherapy had OS comparable with those who had multi-agent adjuvant therapy and TNT, which was better than no adjuvant therapy.

CONCLUSION

Patients achieving pCR after TNT had worse OS than those who had CRT alone, suggesting that the neoadjuvant route by which pCR is achieved is prognostically relevant. Therefore, in the era of neoadjuvant therapy escalation, pCR does not necessarily portend a uniformly favorable prognosis.