Chronicle: results of a randomised phase III trial in locally advanced rectal cancer after neoadjuvant chemoradiation randomising postoperative adjuvant capecitabine plus oxaliplatin (XELOX) versus control

[An update on total neoadjuvant treatment of adenocarcinoma of the rectum]

A major advance has been made in the management of rectal cancer, with the emergence in 2021 of total neoadjuvant treatment. The main publications from the RAPIDO and PRODIGE-23 trials reported a significant improvement in progression-free survival and the pathological complete response rate. The aim of this review is to synthesize recent data on neoadjuvant treatment of rectal cancer, to explain the long-term results of the RAPIDO and PRODIGE-23 trials, and to put them into perspective, considering current advances in de-escalation strategies. The update of the 5-year survival data from the RAPIDO trial highlights an increased risk of loco-regional relapse, with 11.7% of relapses in the experimental group and 8.1% in the control group, while the update of the PRODIGE-23 trial confirms the benefits of this treatment regimen, with a significant improvement in overall survival. In addition, the results of the OPRA and PROPSPECT trials confirm the benefit of total neoadjuvant treatment with induction chemotherapy, as well as the possibility of surgical de-escalation in the OPRA trial and radiotherapy in the PROSPECT trial. The challenge for the future is to identify patients who require total neoadjuvant treatment with the aim of curative surgery to obtain a cure without local or distant relapse, and those for whom therapeutic de-escalation can be envisaged.

The current multidisciplinary management of rectal cancer

Multidisciplinary management of rectal cancer has rapidly evolved over the last several years. This review describes recent data surrounding total neoadjuvant therapy, organ preservation, and management of lateral pelvic lymph nodes. It then presents our treatment algorithm for management of rectal cancer at The University of Texas MD Anderson Cancer Center in the context of this and other existing literature. As part of this discussion, the review describes how we tailor management based upon both patient and tumor-related factors in an effort to optimize patient outcomes.

Risk stratification of stage II rectal mucinous adenocarcinoma to predict the benefit of adjuvant chemotherapy following neoadjuvant chemoradiation and surgery

Background

The treatment strategy for stage II rectal mucinous adenocarcinoma (RMA) recommends neoadjuvant chemoradiotherapy (NCR) followed by total mesorectal excision (TME). However, the necessity of adjuvant chemotherapy (AC) remains controversial.

Materials and methods

Chi-square test was used to assess the relationship between pathological classification, AC and clinicopathological characteristics. Kaplan-Meier (KM) curves and the log-rank test were utilized to analyze differences in overall survival (OS) and cancer-specific survival (CSS) among different groups. Cox regression identified prognostic factors. Nomogram was established utilizing the independent prognostic factors. X-tile divided patients into three risk subgroups.

Results

Compared to RMA, rectal adenocarcinoma (RA) demonstrates longer OS and CSS in all and non-AC stage II patients, with no difference in OS and CSS for AC stage II patients. Propensity score matching analyses yielded similar results. Stratified analysis found that AC both improve OS of RA and RMA patients. Age, gender, pathologic T stage, regional nodes examined, and tumor size were identified as independent prognostic factors for RMA patients without AC. A nomogram was constructed to generate risk scores and categorize RMA patients into three subgroups based on these scores. KM curves revealed AC benefits for moderate and high-risk groups but not for the low-risk group. The external validation cohort yielded similar results.

Conclusions

In summary, our study suggests that, compared to stage II RA patients, stage II RMA patients benefit more from AC after NCR. AC is recommended for moderate and high-risk stage II RMA patients after NCR, whereas low-risk patients do not require AC.

Total Neoadjuvant Therapy (TNT) with Full Dose Concurrent Chemotherapy in Locally Advanced Rectal Adenocarcinoma Including Signet Ring and Mucinous Cancers

PURPOSE

Total neoadjuvant therapy (TNT) with pre-operative chemotherapy and chemoradiotherapy results in improved survival and is becoming the new standard of care in locally advanced rectal cancer (LARC). We describe our experience with TNT consisting of induction chemotherapy followed by chemoradiotherapy using full dose 5FU without oxaliplatin.

METHODS

Adults with biopsy-proven, newly diagnosed LARC with high-risk characteristics on pelvic MRI (T4a or T4b, extramural vascular invasion, N2, mesorectal fascia involvement, enlargement/tumor deposits on lateral lymph nodes) were included. The TNT protocol comprised of six biweekly courses of modified FOLFOX6 followed by pelvic RT with four concurrent cycles of biweekly 5-FU 2600 mg/m2 + LV 200 mg/m2 without oxaliplatin to complete 20 uninterrupted weeks of full dose 5FU. Surgery was planned 11-13 weeks after completing chemoradiotherapy.

RESULTS

Eighty-four LARC patients, including 26% with signet-ring cell carcinoma, with high-risk MRI characteristics were treated with the TNT protocol with a 96% completion rate. Significant (> grade 3) toxicities included neutropenia (23.8%), diarrhea (14.2%) anemia (10.7%), and two deaths. The median DFS at 2 years was 22.5 months with better survival noted for those who underwent surgery or had cCR (with NOM) compared to those who did not undergo surgery (due to progression, inadequate regression, or patient preference despite residual disease) -mDFS 27.7 months versus 11.4 months, p =  < 0.0001 and mOS 29.2 months versus 15 months p =  < 0.0001.

CONCLUSION

The hybrid TNT regimen was administered without significant dose delays or interruptions. Toxicity was manageable but with two treatment-related deaths. Ability to undergo surgery after TNT predicted for improved DFS and OS.

The role of adjuvant chemotherapy in rectal cancer patients with ypT0-2N0 after neoadjuvant chemoradiotherapy

Background

Neoadjuvant chemoradiotherapy has emerged as the established treatment for locally advanced rectal cancer. Nevertheless, there remains a debate regarding the necessity of adjuvant chemotherapy for patients with locally advanced rectal cancer who exhibit a favorable tumor response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery. Thus, the objective of this study is to investigate the impact of adjuvant chemotherapy on the oncological prognosis of rectal cancer patients who have a good response to neoadjuvant chemoradiotherapy.

Materials and methods

The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Articles were searched in the Web of Science, PubMed, and Cochrane Library databases. The primary outcomes assessed were 5-year overall survival, disease-free survival, cancer-specific survival, recurrence-free survival, local recurrence, and distant metastasis. The data was summarized using a random effects model.

Results

A meta-analysis was conducted using 18 retrospective studies published between 2009 and 2023. The studies included 9 from China and 5 from Korea, involving a total of 6566 patients with ypT0-2N0 rectal cancer after neoadjuvant chemoradiotherapy. The pooled data revealed that adjuvant chemotherapy significantly improved 5-year overall survival (OR=1.75, 95% CI: 1.15-2.65, P=0.008), recurrence-free survival (OR=1.73, 95% CI: 1.20-2.48, P=0.003), and reduced distant metastasis (OR=0.68, 95% CI: 0.51-0.92, P=0.011). However, adjuvant chemotherapy did not have a significant effect on disease-free survival, cancer-specific survival, and local recurrence in ypT0-2N0 rectal cancer. Subgroup analysis indicated that adjuvant chemotherapy was beneficial in improving overall survival for ypT1-2N0 rectal cancer (OR=1.89, 95% CI: 1.13-3.19, P=0.003).

Conclusion

The findings of the meta-analysis suggest that adjuvant chemotherapy may provide benefits in terms of oncological outcomes for rectal cancer patients with ypT0-2N0 after neoadjuvant chemoradiotherapy and radical surgery. However, further prospective clinical studies are needed to confirm these findings.

Adjuvant chemotherapy in patients with clinically node-negative but pathologically node-positive rectal cancer in the Netherlands: A retrospective analysis

INTRODUCTION

Accurate clinical staging of rectal cancer is hampered by suboptimal sensitivity of MRI in the detection of regional lymph node metastases. Consequently, some patients may be understaged and have been withheld neoadjuvant (chemo)radiotherapy in retrospect. Although Dutch guidelines do not advocate adjuvant chemotherapy (ACT) in rectal cancer, some of these clinically understaged patients receive ACT according to local policy. We aim to assess the benefit of ACT in these patients.

METHODS

Population-based data from patients with clinically node-negative (cN0) but pathologically node-positive (pN+) rectal cancer that underwent total mesorectal excision (TME) without neoadjuvant treatment between 2008 and 2018 were obtained from the Netherlands Cancer Registry. Missing data were handled by multiple imputation. Stabilised inverse probability treatment weighting (sIPTW) was used to balance clinical characteristics. Overall survival (OS) was compared in ACT and non-ACT patients.

RESULTS

Of 34,724 patients, 13,861 had cN0 disease of whom 3016 were pN+ (21.8%). 1466 (48.6%) of these patients underwent upfront TME and were included. Median follow-up was 84 months (95% confidence interval [CI] 76-97) versus 79 months (95% CI 77-81) in patients that did (n = 290, 19.8%) and did not (n = 1176, 80.2%) receive ACT, respectively. After sIPTW adjustment, ACT was associated with improved OS (hazard ratio 0.70; 95% CI 0.49-0.99; p = 0.04). The estimated 5-year OS rate was 74.2% versus 65.3%, respectively.

CONCLUSION

In this population-based cohort of patients with cN0 but pN+ rectal cancer who underwent upfront TME, ACT was associated with a significant OS benefit. These data support to discuss ACT in this population.

Neoadjuvant S-1 and oxaliplatin plus bevacizumab therapy for high-risk locally advanced rectal cancer: A prospective multicenter phase II study

Aim

We report the short/mid-term results of surgery for high-risk locally advanced rectal cancer (LARC) after neoadjuvant chemotherapy (NAC, four courses of S-1 + oxaliplatin+ bevacizumab) without radiotherapy with the primary aim of ypT0-2.

Methods

High-risk LARC was defined as cT4b, mesorectal fascia (MRF) ≤1 mm (MRF+), or lateral lymph node metastasis (cLLN+) on high-resolution MRI. The planned 32 cases from April 2018 to December 2021 were all included.

Results

There were 10 patients at cT4b (31.2%), 26 MRF+ (81.3%), and 22 cLLN+ (68.8%). Thirteen (40.6%) underwent NAC after a colostomy for stenosis. NAC was completed in 26 (81.2%) cases. Grade 3 or higher adverse events occurred in six (18.7%). One patient developed progressive disease (3.2%). Eleven were ycT0-3MRF-LLN- (34.3%). Curative-intent surgery was performed on 31, with sphincter-preserving surgery in 20, abdominoperineal resection in nine, total pelvic exenteration in two, and lateral lymph node dissection in 24. Two had R1/2 resection (6.4%). A Grade 3 or higher postoperative complication rate occurred in 3.2%. Pathological complete response and ypT0-2 rates were 12.9% and 45.1%. Three-year disease-free survival rates (3yDFS) for ypT0-2 and ypT ≥3 were 81.2%, 46.6% (p = 0.061), and 3-year local recurrence rates (3yLR) were 0%, 48.8% (p = 0.015). 3yDFS for ycT0-3MRF-LLN- and ycT4/MRF+/LLN+ were 87.5%, 48.0% (p = 0.031) and 3yLR were 0%, 42.8% (p = 0.045).

Conclusion

NAC yielded a clinically significant effect in about half of high-risk LARC patients. If NAC alone is ineffective, radiotherapy should be added, even if extended surgery is intended.

The role of total neoadjuvant therapy in locally advanced rectal cancer: a survey of specialists attending the All-Ireland Colorectal Cancer Conference 2022 including lead investigators of OPRA, PRODIGE-23 and RAPIDO

BACKGROUND

The treatment of locally advanced rectal cancer (LARC) has evolved following recent landmark trials of total neoadjuvant therapy (TNT)-the delivery of preoperative chemotherapy sequenced with radiation.

AIM

To assess the preferences of colorectal surgery (CRS), radiation oncology (RO) and medical oncology (MO) specialists attending the All-Ireland Colorectal Cancer Conference (AICCC) 2022 regarding the neoadjuvant management of LARC.

METHODS

A live electronic survey explored the preferred treatment approach and TNT regimen for early-, intermediate-, bad-, and advanced-risk categories of rectal cancer according to the European Society of Medical Oncology (ESMO) guidelines. The survey was preceded by an update from lead investigators of TNT trials (OPRA, PRODIGE-23 and RAPIDO), who then participated in a multidisciplinary panel discussion.

RESULTS

Ten CRS, 7 RO and 15 MO (32 of 45 specialists) participated fully in the survey resulting in a response rate of 71%. Ninety-four percent, 76% and 53% of specialists preferred a TNT approach for patients with advanced, bad, and intermediate-risk rectal cancer, respectively. A consolidation TNT regimen of long-course chemoradiotherapy followed by chemotherapy was the most preferred regimen. Upfront surgery was preferred by 77% for early-risk disease.

CONCLUSION

This survey illustrated the general acceptance of TNT by rectal cancer specialists attending the AICCC as a valuable treatment strategy for higher-risk category LARC. Whilst the treatment of LARC changes, it remains best practice to individualize care, incorporating the selective use of TNT as discussed by an MDT and in keeping with the patient's goals of care.

Quality of Surgical Outcome Reporting in Randomised Clinical Trials of Multimodal Rectal Cancer Treatment: A Systematic Review

INTRODUCTION

Randomised controlled trials (RCTs) continue to provide the best evidence for treatment options, but the quality of reporting in RCTs and the completeness rate of reporting of surgical outcomes and complication data vary widely. The aim of this study was to measure the quality of reporting of the surgical outcome and complication data in RCTs of rectal cancer treatment and whether this quality has changed over time.

METHODS

Eligible articles with the keywords ("rectal cancer" OR "rectal carcinoma") AND ("radiation" OR "radiotherapy") that were RCTs and published in the English, German, Polish, or Italian language were identified by reviewing all abstracts published from 1982 through 2022. Two authors independently screened and analysed all studies. The quality of the surgical outcome and complication data was assessed based on fourteen criteria, and the quality of RCTs was evaluated based on a modified Jadad scale. The primary outcome was the quality of reporting in RCTs and the completeness rate of reporting of surgical results and complication data.

RESULTS

A total of 340 articles reporting multimodal therapy outcomes for 143,576 rectal cancer patients were analysed. A total of 7 articles (2%) met all 14 reporting criteria, 13 met 13 criteria, 27 met from 11 to 12 criteria, 36 met from 9 to 10 criteria, 76 met from 7 to 8 criteria, and most articles met fewer than 7 criteria (mean 5.5 criteria). Commonly underreported criteria included complication severity (15% of articles), macroscopic integrity of mesorectal excision (17% of articles), length of stay (18% of articles), number of lymph nodes (21% of articles), distance between the tumour and circumferential resection margin (CRM) (26% of articles), surgical radicality according to the site of the primary tumour (R0 vs. R1 + R2) (29% of articles), and CRM status (38% of articles).

CONCLUSION

Inconsistent surgical outcome and complication data reporting in multimodal rectal cancer treatment RCTs is standard. Standardised reporting of clinical and oncological outcomes should be established to facilitate comparing studies and results of related research topics.

Practice-changing clinical trials in radiation oncology for gastrointestinal malignancies in 2021-2023

Gastrointestinal cancers are one of the most frequent cancers and a leading cause of cancer deaths worldwide. We provide an overview of the most important practice-changing trials that were either published or presented at the international scientific meetings in 2021-2023. Highlights included reports on three phase III trials (CONCORDE/PRODIGE 26, ARTDECO, and a study by Xu et al.) that evaluated dose escalation in the definitive setting for locally advanced oesophageal cancers, as well as two phase III trials that evaluated the role of chemotherapy (neo-AEGIS) and targeted therapy (NRG/RTOG 1010) in the neoadjuvant setting for adenocarcinoma oesophageal cancers or gastroesophageal junction cancer. CheckMate 577 evaluated nivolumab in patients who had residual pathological disease after neoadjuvant chemoradiation followed by complete resection. The use of radiation therapy for borderline and locally advanced pancreatic cancer is also discussed (SMART and CONKO-007 trials). Stereotactic body radiation therapy followed by sorafenib was compared to sorafenib alone in patients with hepatocellular carcinoma in the NRG/RTOG 1112 study. New options in the management of rectal cancer are emerging such as total neoadjuvant treatment (PRODIGE 23, RAPIDO, PROSPECT), organ preservation (OPRA, OPERA), and the role of immunotherapy in patients with DNA mismatch-repair deficient/microsatellite instability. Finally, preliminary results of the ACT 4 trial that evaluated de-escalation in anal cancer are presented.

Protective effect of miR-18a in resected liver metastases of colorectal cancer and FOLFOX treatment

BACKGROUND

Colorectal cancer ranks second in terms of cancer associated deaths worldwide, whereas miRNA play a pivotal role in the etiology of cancer and its metastases.

AIMS

Studying the expression and cellular function of miR-18a in metastatic colorectal cancer and association to progression-free survival.

METHODS AND RESULTS

Colorectal liver metastases (N = 123) and primary colorectal cancer (N = 27) where analyzed by RT-PCR and correlated with clinical follow up data. Invasion and migration assays were performed with the liver metastatic cell line LIM2099 after miR-18a knockdown. Cell viability under FOLFOX treatment and knockdown was measured. We found that the expression of miR-18a was increased 4.38-fold in liver metastases and 3.86-fold in colorectal tumor tissue compared to healthy liver tissue and colorectal mucosa, respectively (p ≤ .001). Patients with a high miR-18a expression in liver metastases had a progression-free survival (PFS) of 13.6 months versus 8.9 months in patients with low expression (N = 123; p = .024). In vitro migration of LIM2099 cells was reduced after miR-18a knockdown and cell viability was significantly increased after miR-18a knockdown and treatment with folinic acid or oxaliplatin. Subgroup analysis of PFS revealed significant benefits for patients with high miR-18a expression receiving 5-FU, folinic acid or oxaliplatin.

CONCLUSIONS

High expression of miR-18a in colorectal liver metastases might have a protective effect after resection of metastases and FOLFOX treatment regarding PFS.

Phase II study of capecitabine-based concomitant chemoradiation followed by durvalumab as a neoadjuvant strategy in locally advanced rectal cancer: the PANDORA trial

BACKGROUND

This study investigated the efficacy of chemoradiotherapy (CRT) followed by durvalumab as neoadjuvant therapy of locally advanced rectal cancer.

PATIENTS AND METHODS

The PANDORA trial is a prospective, phase II, open-label, single-arm, multicenter study aimed at evaluating the efficacy and safety of preoperative treatment with durvalumab (1500 mg every 4 weeks for three administrations) following long-course radiotherapy (RT) plus concomitant capecitabine (5040 cGy RT in 25-28 fractions over 5 weeks and capecitabine administered at 825 mg/m2 twice daily). The primary endpoint was the pathological complete response (pCR) rate; secondary endpoints were the proportion of clinical complete remissions and safety. The sample size was estimated assuming a null pCR proportion of 0.15 and an alternative pCR proportion of 0.30 (α = 0.05, power = 0.80). The proposed treatment could be considered promising if ≥13 pCRs were observed in 55 patients (EudraCT: 2018-004758-39; NCT04083365).

RESULTS

Between November 2019 and August 2021, 60 patients were accrued, of which 55 were assessable for the study's objectives. Two patients experienced disease progression during treatment. Nineteen out of 55 eligible patients achieved a pCR (34.5%, 95% confidence interval 22.2% to 48.6%). Regarding toxicity related to durvalumab, grade 3 adverse events (AEs) occurred in four patients (7.3%) (diarrhea, skin toxicity, transaminase increase, lipase increase, and pancolitis). Grade 4 toxicity was not observed. In 20 patients (36.4%), grade 1-2 AEs related to durvalumab were observed. The most common were endocrine toxicity (hyper/hypothyroidism), dermatologic toxicity (skin rash), and gastrointestinal toxicity (transaminase increase, nausea, diarrhea, constipation).

CONCLUSION

This study met its primary endpoint showing that CRT followed by durvalumab could increase pCR with a safe toxicity profile. This combination is a promising, feasible strategy worthy of further investigation.

Adjuvant chemotherapy in locally advanced rectal cancer after neo-adjuvant concurrent chemoradiotherapy and surgery: A retrospective study in Vietnamese patients

Background

Advances in preoperative chemoradiotherapy and surgical techniques offered improvements in rates of locoregional recurrence but did not address distant metastasis. Traditionally, adjuvant chemotherapy has been administered with the goal of limiting systemic recurrences.

Objective

Evaluation of the efficacy and safety of adjuvant chemotherapy in patients with locally advanced rectal cancer after preoperative chemoradiotherapy and surgery.

Methods

From January 2017 to December 2018, 103 patients diagnosed with clinical stage II or III rectal cancer received adjuvant chemotherapy with capecitabine or XELOX regimens after neoadjuvant concurrent chemoradiotherapy and total mesorectal excision. Overall survival, disease-free survival, and toxicity were analyzed.

Results

The median follow-up time was 52.5 months (6.5-66.8 months). The mean 3-year disease-free survival and 3-year overall survival were 86.2% (95% CI: 82.8-89.6) and 92.2% (95% CI: 86.9-97.5), respectively. The rate of hematologic and nonhematologic toxicity was low, mostly grades 1 and 2 including anemia, leucopenia, thrombocytopenia, and liver enzymes elevations were 85.4, 50.5, 42.8, and 45.6%, respectively.

Conclusion

The capecitabine and XELOX regimen in adjuvant settings for rectal cancer patients receiving neoadjuvant chemoradiotherapy and surgery was a safe and effective modality. Further randomized trials need to be conducted to evaluate the role of postoperative therapy for these individuals.

Improved Survival After Adjuvant Therapy in Locally Advanced Rectal Cancer Patients With Pathologic Complete Response

BACKGROUND

The benefit of adjuvant therapy is unclear in patients with rectal cancer achieving a pathologic complete response after neoadjuvant chemoradiotherapy and total mesorectal excision.

OBJECTIVE

This study aimed to assess the benefit of adjuvant chemotherapy on survival among rectal cancer patients with a pathologic complete response after neoadjuvant chemoradiation.

DESIGN

Retrospective cohort study.

SETTING

National Cancer Database (2004-2017).

PATIENTS

Patients with clinical stage 2 or 3 rectal adenocarcinoma who underwent neoadjuvant chemoradiation (50-50.4 Gy in 25-28 fractions) followed by total mesorectal excision with a pathologic complete response were included.

INTERVENTION

Adjuvant chemotherapy.

MAIN OUTCOME MEASURES

Overall survival.

RESULTS

There were 20,518 patients and 2221 (11%) had a pathologic complete response after neoadjuvant chemoradiation. Of 2221 patients, 1441 (65%) did not receive adjuvant therapy and 780 (35%) did. Patients who received adjuvant therapy were more likely to be younger (median 58 vs 62 y), have private insurance (61% vs 49%), and have node-positive disease (57% vs 48%) (all p < 0.05). There were no differences in sex, race, Charlson-Deyo score, clinical T-stage, tumor size and differentiation, adequate lymphadenectomy (12 or more), or sphincter preservation between groups (all p > 0.05). Overall survival at 5, 10, and 14 years was significantly longer in the adjuvant group (93%, 85%, 83%, respectively) compared to patients who did not receive adjuvant therapy (87%, 67%, 51%, respectively) ( p < 0.001). In a subgroup analysis, adjuvant therapy was associated with improved survival in patients with clinical stage 2 and 3 rectal cancer ( p < 0.001). After adjusting for patient and tumor characteristics, omission of adjuvant chemotherapy was associated with significantly worse survival (HR 1.53, 95% 1.08-2.16).

LIMITATIONS

Selection bias, unknown perioperative morbidity, chemotherapy regimen, recurrence status, and other unidentified factors limiting survival analysis.

CONCLUSIONS

In patients with clinical stage 2 or 3 rectal cancer, adjuvant chemotherapy was associated with improved overall survival in patients achieving a pathological complete response after neoadjuvant chemoradiotherapy. See Video Abstract at http://links.lww.com/DCR/C139 .

SOBREVIDA MEJORADA DESPUS DE LA TERAPIA ADYUVANTE EN PACIENTES CON CNCER DE RECTO LOCALMENTE AVANZADO CON RESPUESTA PATOLGICA COMPLETA

ANTECEDENTES:En los pacientes con cáncer de recto que logran una respuesta patológica completa después de la quimiorradioterapia neoadyuvante y la escisión total del mesorrecto, el beneficio de la terapia adyuvante no está claro.OBJETIVO:Evaluar el beneficio de la quimioterapia adyuvante en la sobrevida de los pacientes con cáncer de recto con una respuesta patológica completa después de la quimiorradioterapia neoadyuvante.DISEÑO:Estudio de cohorte retrospectivo.ESCENARIO:Base de Datos Nacional de Cáncer (2004-2017).PACIENTES:Pacientes con adenocarcinoma rectal en estadio clínico 2 ó 3 que se sometieron a quimiorradiación neoadyuvante (50-50,4 Gy en 25-28 fracciones) seguida de escisión mesorrectal total con una respuesta patológica completa.INTERVENCIÓN:Quimioterapia adyuvante.PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida global.RESULTADOS:Hubo 20.518 pacientes y 2.221 (11%) tuvieron una respuesta patológica completa después de la quimiorradiación neoadyuvante. Entre estos 2221 pacientes, 1441 (65%) no recibieron terapia adyuvante y 780 (35%) sí. Los pacientes que recibieron terapia adyuvante tenían más probabilidades de ser más jóvenes (mediana de 58 frente a 62 años), tener un seguro privado (61% frente a 49%) y tener enfermedad con linfonodos positivos (57% frente a 48 %) (todos p < 0,05). No hubo diferencias en género, raza, puntuación de Charlson-Deyo, estadio T clínico, tamaño y diferenciación del tumor, linfadenectomía adecuada (≥12) o preservación del esfínter entre los grupos (todos p > 0,05). La sobrevida general a los 5, 10 y 14 años fue significativamente mayor en el grupo adyuvante (93%, 85%, 83%, respectivamente) en comparación con los pacientes que no recibieron terapia adyuvante (87%, 67%, 51% respectivamente) ( p < 0,001). En un análisis de subgrupos, la terapia adyuvante se asoció con una mejor sobrevida general en pacientes con cáncer de recto en estadio clínico 2 y 3 ( p < 0,001). Después de ajustar por las características del paciente y del tumor, la omisión de la quimioterapia adyuvante se asoció con una sobrevida global significativamente peor (HR 1,53, IC del 95%, 1,08-2,16).LIMITACIONES:Sesgo de selección; morbilidad perioperatoria desconocida, régimen de quimioterapia, estado de recurrencia y otros factores no identificados que limitan el análisis de sobrevida.CONCLUSIONES:En pacientes con cáncer de recto en estadio clínico 2 ó 3, la quimioterapia adyuvante se asoció con una mejor sobrevida general en pacientes que lograron una respuesta patológica completa después de la quimiorradioterapia neoadyuvante. Consulte Video Resumen en http://links.lww.com/DCR/C139 . (Traducción-Dr. Felipe Bellolio ).

pCR and 2-Year Disease-Free Survival: A Combination of the Two Endpoints as a New Classification for Locally Advanced Rectal Cancer Patients-An Updated Pooled Analysis of Eleven International Randomized Trials

LARC is managed by multimodal treatments whose intensity can be highly modulated. In this context, we need surrogate endpoints to help predict long-term outcomes and better personalize treatments. A previous study identified 2yDFS as a stronger predictor of OS than pCR in LARC patients undergoing neoadjuvant RT. The aim of this pooled analysis was to assess the role of pCR and 2yDFS as surrogate endpoints for OS in a larger cohort. The pooled and subgroup analyses were performed on large rectal cancer randomized trial cohorts who received long-course RT. Our analysis focused on the evaluation of OS in relation to the pCR and 2-year disease status. A total of 4600 patients were analyzed. Four groups were identified according to intermediate outcomes: 12% had both pCR and 2yDFS (the better); 67% achieved 2yDFS but not pCR (the good); 1% had pCR but not 2yDFS; and 20% had neither pCR nor 2yDFS (the bad). The pCR and 2yDFS were favorably associated with OS in the univariate analysis, and 2yDFS maintained a statistically significant association in the multivariate analysis independently of the pCR status. The combination of the pCR and 2yDFS results in a strong predictor of OS, whereas failure to achieve 2yDFS carries a poor prognosis regardless of the pCR status. This new stratification of LARC patients could help design predictive models where the combination of 2yDFS and pCR should be employed as the primary outcome.

Total neoadjuvant therapy versus chemoradiotherapy for locally advanced rectal cancer: Bayesian network meta-analysis

BACKGROUND

Total neoadjuvant therapy is a promising treatment for locally advanced rectal cancer, utilizing either short-course radiotherapy or long-course chemoradiotherapy, but their relative efficacy remains unclear. The aim of this Bayesian network meta-analysis was to investigate clinical outcomes amongst patients receiving total neoadjuvant therapy with short-course radiotherapy or long-course chemoradiotherapy, and those receiving long-course chemoradiotherapy alone.

METHODS

A systematic literature search was performed. All studies that compared at least two of these three treatments for locally advanced rectal cancer were included. The primary endpoint was the pathological complete response rate, and survival outcomes were adopted as secondary outcomes.

RESULTS

Thirty cohorts were included. Compared with long-course chemoradiotherapy, both total neoadjuvant therapy with long-course chemoradiotherapy (OR 1.78, 95 per cent c.i. 1.43 to 2.26) and total neoadjuvant therapy with short-course radiotherapy (OR 1.75, 95 per cent c.i. 1.23 to 2.50) improved the pathological complete response rate. Similar benefits were observed in the sensitivity and subgroup analyses, except for short-course radiotherapy with one to two cycles of chemotherapy. No significant differences in survival outcomes were found amongst the three treatments. Long-course chemoradiotherapy with consolidation chemotherapy (HR 0.44, 95 per cent c.i. 0.20 to 0.99) exhibited higher disease-free survival than long-course chemoradiotherapy alone.

CONCLUSION

Compared with long-course chemoradiotherapy, both short-course radiotherapy with greater than or equal to three cycles of chemotherapy and total neoadjuvant therapy with long-course chemoradiotherapy can improve the pathological complete response rate, and long-course chemoradiotherapy with consolidation chemotherapy may lead to a marginal benefit in disease-free survival. The pathological complete response rate and survival outcomes are similar for total neoadjuvant therapy with short-course radiotherapy or long-course chemoradiotherapy.

Adjuvant chemotherapy does not improve cancer-specific survival for pathologic stage II/III rectal adenocarcinoma after neoadjuvant chemoradiotherapy and surgery: evidence based on long-term survival analysis from SEER data

PURPOSE

Adjuvant chemotherapy is controversial in rectal cancer, especially after neoadjuvant chemoradiotherapy (NCRT). This retrospective study aims at evaluating adjuvant chemotherapy's long-term survival benefits in stage II and stage III rectal adenocarcinoma (RC).

METHODS

This study obtained data from the Surveillance, Epidemiology, and End Results (SEER) database registered between 2010 and 2015. The survival analyses used the Kaplan-Meier method and were compared by log-rank test. The factors that affect survival outcomes were analyzed by univariate and multivariate Cox regression. The propensity score matching (1:4) was used to ensure the balance of variables between different groups.

RESULTS

The median follow-up time for overall patients was 64 months. The 5-year overall survival (OS) and cancer-specific survival (CSS) rates were 51.3% and 67.4% in the adjuvant chemotherapy (-) group and 73.9% and 79.6% in the adjuvant chemotherapy ( +) group (p < 0.001, p = 0.002). However, subgroup analysis showed adjuvant chemotherapy after NCRT improved the 5-year OS but not CSS rates in stage II and stage III RC (p = 0.003, p = 0.004; p = 0.29, p = 0.3). Univariate and multivariate analyses found adjuvant chemotherapy after NCRT was an independent prognosis factor of OS but not CSS (HR 0.8, 95%CI 0.7-0.92, p < 0.001; p = 0.276).

CONCLUSION

The survival benefits from adjuvant chemotherapy were associated with the status of NCRT for pathological stage II and III RC. For patients who did not receive NCRT, adjuvant chemotherapy is needed to significantly improve long-term survival rates. However, adjuvant chemotherapy after NCRT did not significantly improve long-term CSS.

Preoperative chemoradiotherapy using tegafur/uracil, oral leucovorin, and irinotecan (TEGAFIRI) followed by oxaliplatin-based chemotherapy as total neoadjuvant therapy for locally advanced rectal cancer: the study protocol for a phase II trial

BACKGROUND

Total neoadjuvant therapy (TNT) is a novel treatment strategy that is an alternative to preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). However, an optimal protocol for TNT has not yet been established. The present study will be an open-label, single-arm, single-center trial to develop a new protocol.

METHODS

Thirty LARC patients at high risk of distant metastasis will receive CRT consisting of long-course radiation, concurrent with tegafur/uracil, oral leucovorin, irinotecan (TEGAFIRI), followed by mFOLFOX-6 or CAPOX before undergoing surgery.

DISCUSSION

Since previous findings showed a high percentage of grade 3-4 adverse events with the TEGAFIRI regimen for CRT and TNT, the primary outcome of this study will be safety and feasibility. Our regimen for CRT consists of the biweekly administration of irinotecan for good patient compliance. The novel combination approach of this treatment may improve the long-term outcomes of LARC.

TRIAL REGISTRATION

Japan Registry of Clinical Trials jRCTs031210660.

A systematic review and network meta-analysis of randomised controlled trials comparing neoadjuvant treatment strategies for stage II and III rectal cancer

AIM

Multiple neoadjuvant therapy strategies have been used and compared for rectal cancer and there has been no true consensus as to the optimal neoadjuvant therapy regimen. The aim is to identify and compare the neoadjuvant therapies available for stage II and III rectal cancer.

DESIGN

A systematic literature review was performed, from inception to August 2022, of the following databases: MEDLINE, EMBASE, Science Citation Index Expanded, Cochrane Library. Only randomized controlled trials comparing neoadjuvant therapies for stage II and III rectal cancer were considered. Stata was used to draw network plots, and a Bayesian network meta-analysis was conducted through models utilizing the Markov Chain Monte Carlo method in WinBUGS.

RESULTS

A total of 58 articles were included based on 41 randomised controlled trials, reporting on 12,404 participants that underwent 15 neoadjuvant treatment regimens. No significant difference was identified between treatments for major or total postoperative complications, anastomotic leak rates, or sphincter-saving surgery. Straight to surgery (STS) ranked as best treatment for preoperative toxicity but ranked worst treatment for positive resection margins and complete response. STS had significantly increased positive resection margins compared to long-course chemoradiotherapy with short-wait (LCCRT-SW) or long-wait (LCCRT-LW) to surgery, or short-course radiotherapy with short-wait (SCRT-SW) or immediate surgery (SCRT-IS). LCCRT-SW or LCCRT-LW resulted in significantly increased complete response rates compared to STS. LCCRT-LW significantly improved 2-year overall survival compared to STS, SCRT-IS, SCRT-SW. Total neoadjuvant therapy regimes with short-course radiotherapy followed by consolidation chemotherapy (SCRT-CT-SW), induction chemotherapy followed by long-course chemoradiotherapy (CT-LCCRT-S), long-course chemoradiotherapy followed by consolidation chemotherapy (LCCRT-CT-S), significantly improved positive resection margins, complete response, and disease-free survival compared to STS. Chemotherapy with monoclonal antibodies followed by long-course chemoradiotherapy (CT+MAB-LCCRT+MAB-S) significantly improved complete response and positive resection margins compared to STS, and 2-year disease-free survival compared to STS, SCRT-IS, SCRT-SW, SCRT-CT-SW, LCCRT-SW, LCCRT-LW. CT+MAB-LCCRT+MAB-S ranked as best treatment for disease-free survival and overall survival.

CONCLUSIONS

Conventional neoadjuvant therapies with short-course radiation or long-course chemoradiotherapy have oncological benefits compared to no neoadjuvant therapy without increasing perioperative complication rates. Prolonged wait to surgery may improve oncological outcomes. Total neoadjuvant therapies provide additional benefits in terms of complete response, positive resection margins, and disease-free survival. Monoclonal antibody therapy may further improve oncological outcomes but currently is only applicable to a small subgroup of patients and requires further validation.

The impact of adjuvant chemotherapy on survival in mucinous and non-mucinous rectal adenocarcinoma patients after TME surgery

INTRODUCTION

The value of adjuvant chemotherapy for rectal cancer patients is debated and varies in different subgroups. One such subgroup is mucinous adenocarcinoma (MAC), which is more treatment resistant compared to non-mucinous adenocarcinoma (NMAC). To date, mucinous histology is not taken into account when deciding on adjuvant treatment strategy. This is the first study to exclusively include patients with rectal cancer, then separate MAC and NMAC and compare the survival in patients that had or did not have adjuvant chemotherapy.

MATERIAL AND METHODS

The study included retrospective register data from 365 Swedish patients with stage II-IV rectal adenocarcinoma, 56 patients with MAC and 309 patients with NMAC. All patients were considered curative, had surgery with total mesorectal excision in 2004-2013, and were followed up until death or 2021.

RESULTS

Patients with MAC that had adjuvant chemotherapy had better overall survival (OS, HR 0.42; CI 95%: 0.19-0.93; p = 0.032) and a trend towards better cancer-specific survival (CSS, HR 0.41 CI 95%: 0.17-1.03; p = 0.057) compared to patients without chemotherapy (HR 0.42; CI 95%: 0.19-0.93; p = 0.032). The difference in OS was still significant even after adjusting for sex, age, stage, differentiation, neoadjuvant chemotherapy and preoperative radiotherapy (HR 0.40; CI 95%: 0.17-0.92; p = 0.031). There was no such difference in the NMAC patients except in the stage-by-stage subgroup analyses where patients in stage IV had better survival after adjuvant chemotherapy.

CONCLUSIONS

There may be a difference in treatment response to adjuvant chemotherapy between MAC and NMAC patients. Patients with MAC could possibly benefit from adjuvant chemotherapy in stages II-IV. Further studies are however needed to confirm these results.

Chemotherapy Duration for Various Indications in Colorectal Cancer: a Review

PURPOSE OF REVIEW

The treatment of colorectal cancer (CRC) has evolved and become more personalized during the past several years. For example, depotentiation/reduced duration of systemic therapies has proven to be beneficial in both advanced and early stages of the disease.

RECENT FINDINGS

In particular, recent randomized studies of stage III and high-risk stage II CRC showed that a shorter duration (3 months), when compared to the historical 6-month comparator, provides nearly similar overall survival (OS) and disease-free survival (DFS). In the setting of advanced, inoperable CRC, a relatively short induction phase (six to eight cycles) followed by biological agents is the current standard of care in RAS wild-type (wt). versus RAS mutated cases. With regard to potentially operable stage IV disease (with the aim of converting liver metastases to operability), a relatively short number of cycles (four to six cycles) should be offered with re-staging and re-evaluation for surgery as soon as possible in most cases. For inoperable liver metastases, a relatively intensive triplet or doublet plus targeted therapy may attain conversion in some cases and may even result in cure. Rectal cancer treatment continues to be a complex disease in terms of treatment and oncological results. Recent data seem to showcase the benefits of more prolonged sequential strategies (total neoadjuvant therapy, all treatment delivered before surgery, to reduce the risk of distant metastases and local control). In recent years, different strategies regarding treatment intensity have been employed in CRC in adjuvant and metastatic setting. Introduction of triplets as first-line therapy for colon cancer and as induction phase for rectal cancer are now therapeutic options. Conversely in stage II disease or low-risk stage III resected CRC, a reduced chemotherapy length is a new standard of care.

An International Multicenter Prospective Study Evaluating the Long-term Oncological Impact of Adjuvant Chemotherapy in ypN+ Rectal Cancer

OBJECTIVE

To assess the oncological benefit of adjuvant chemotherapy (AC) in node positive (ypN+) rectal cancer after neoadjuvant chemoradiotherapy and radical surgery.

BACKGROUND

The evidence for AC after total mesorectal excision for locally advanced rectal cancer is conflicting and the net survival benefit is debated.

METHODS

An international multicenter comparative cohort study was performed comparing oncological outcomes in tertiary rectal cancer centers from the Netherlands and France. Patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by total mesorectal excision surgery and with positive lymph nodes on histologic examination (ypN+) were included for analysis. Kaplan-Meier curves were generated to compare disease-free (DFS) and overall survival in AC and non-AC groups.

RESULTS

Of 1265 patients screened, a total of 239 rectal cancer patients with ypN+ disease were included. Demographic and clinical characteristics were similar in both groups. Higher systemic recurrence rates were observed in the non-AC group compared with those who received AC [32.0% (n=40) vs 17.5% (n=11), respectively, P =0.034]. DFS at 1 and 5 years postoperatively were significantly better in the AC group (92% vs 80% at 1 year; 72% vs 51% at 5 years, P =0.024), whereas no difference in overall survival was observed.

CONCLUSIONS

In this multicenter comparative cohort study, we identified an oncological benefit of AC in both systemic recurrence and DFS in ypN+ rectal cancer patients. From this data, systemic chemotherapy continues to confer oncological benefit in locally advanced ypN+ rectal cancer.

Is There a Role for Adjuvant Chemotherapy in Pathologic Node-Negative Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiation Therapy?

BACKGROUND

Neoadjuvant chemoradiation therapy (NCRT, 5-fluorouracil and radiation) followed by resection and adjuvant chemotherapy (AC) is one of the standard treatment paradigms for locally advanced rectal adenocarcinoma. However, the utility of AC in patients with pathologic lymph node (pLN)-negative disease is unclear. Our aim is to assess the value of AC stratified by pLN status.

METHODS

The US Rectal Cancer Consortium database (2007-2017) was retrospectively reviewed for patients with clinical stage II and III rectal adenocarcinoma who received neoadjuvant chemoradiation (NACR) and curative-intent resection. Those who received neoadjuvant systemic chemotherapy or underwent local resection were excluded. Patients were categorized by pLN status. Primary outcome was overall survival (OS).

RESULTS

Of 213 patients, 70% had pLN-negative disease and 30% pLN-positive disease. Median age was 57 years, 65% were male, and median follow-up was 31 months. Among patients with pLN-negative disease, 74% received AC. Receipt of AC was not associated with improved 5-year OS (82% versus 74%, respectively; p = 0.16). This finding persisted on multivariable analysis. Of patients with pLN-positive disease, 83% received AC. Patients with pLN-positive disease demonstrated improved 5-year OS with receipt of AC (72% compared with 0% with no adjuvant chemotherapy, p = 0.04).

CONCLUSION

After receiving neoadjuvant chemoradiation, adjuvant chemotherapy for patients with pLN-negative disease does not appear to be associated with improved survival. Further validation and prospective studies are needed to evaluate the utility of adjuvant chemotherapy in this setting.

Strategies to Optimize Treatment for Locally Advanced Rectal Cancer

Neoadjuvant long-course concurrent chemoradiation plus surgery, followed by optional adjuvant chemotherapy, is a standard of care for locally advanced rectal cancer (LARC). However, this traditional approach has several limitations, including low pathological complete response (pCR) (10-25%), high metastasis rate (30-35%), and highly inconsistent compliance with adjuvant chemotherapy (25-75%). Treatment modalities for LARC have dramatically evolved in recent years. Multiple clinical trials have focused on optimizing strategies to achieve a win-win situation for oncologic outcomes and functions. Here, we review the latest studies into optimizing neoadjuvant treatment for LARC.

Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

Background

For rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Methods

The study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan-Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).

Results

Of 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.

Conclusion

Adjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Acute toxicities of patients with locally advanced rectal cancer treated with intensified chemoradiotherapy within the CAO/ARO/AIO-12 trial: comparing conventional versus VMAT planning at a single center

In locally advanced rectal cancer (LARC) neoadjuvant chemoradiotherapy is regarded as standard treatment. We assessed acute toxicities in patients receiving conventional 3D-conformal radiotherapy (3D-RT) and correlated them with dosimetric parameters after re-planning with volumetric modulated arc therapy (VMAT). Patients were randomized within the multicenter CAO/ARO/AIO-12 trial and received 50.4 Gy in 28 fractions and simultaneous chemotherapy with fluorouracil and oxaliplatin. Organs at risk (OAR) were contoured in a standardized approach. Acute toxicities and dose volume histogram parameters of 3D-RT plans were compared to retrospectively calculated VMAT plans. From 08/2015 to 01/2018, 35 patients with LARC were treated at one study center. Thirty-four patients were analyzed of whom 1 (3%) was UICC stage II and 33 (97%) patients were UICC stage III. Grade 3 acute toxicities occurred in 5 patients (15%). Patients with acute grade 1 cystitis (n = 9) had significantly higher D_mean values for bladder (29.4 Gy vs. 25.2 Gy, p < 0.01) compared to patients without bladder toxicities. Acute diarrhea was associated with small bowel volume (grade 2: 870.1 ccm vs. grade 0-1: 647.3 ccm; p < 0.01) and with the irradiated volumes V5 to V50. Using VMAT planning, we could reduce mean doses and irradiated volumes for all OAR: D_mean bladder (21.9 Gy vs. 26.3 Gy, p < 0.01), small bowel volumes V5-V45 (p < 0.01), D_mean anal sphincter (34.6 Gy vs. 35.6 Gy, p < 0.01) and D_mean femoral heads (right 11.4 Gy vs. 25.9 Gy, left 12.5 Gy vs. 26.6 Gy, p < 0.01). Acute small bowel and bladder toxicities were dose and volume dependent. Dose and volume sparing for all OAR could be achieved through VMAT planning and might result in less acute toxicities.

Pathologic Implications of Radial Resection Margin and Perineural Invasion to Adjuvant Chemotherapy after Preoperative Chemoradiotherapy and Surgery for Rectal Cancer: A Multi-Institutional and Case-Matched Control Study

We assessed the exact role of adjuvant chemotherapy after neoadjuvant chemoradiotherapy (CRT) and surgery in rectal cancer patients with positive surgical margin or perineural invasion (PNI). This multi-institutional study included 1799 patients with rectal cancer at cT3-4N0-2M0 stages. Patients were divided into two groups. The high-risk group had a positive margin and/or perineural invasion. The low-risk group showed no positive margin or PNI. Propensity-score matching analysis was performed, and a total of 928 patients, with 464 in each arm, were evaluated. The high-risk group showed significant differences in overall survival (OS, 73.4% vs. 53.9%, p < 0.01) and recurrence-free survival (RFS, 52.7% vs. 40.9%, p = 0.01) at five years between the adjuvant chemotherapy arm and observation arm. The low-risk group showed no significant differences in 5-year OS (p = 0.61) and RFS (p = 0.75) between the two arms. Multivariate analyses showed that age, pathologic N stage, and adjuvant chemotherapy were significantly correlated with OS and RFS in the high-risk group (all p < 0.05). Adjuvant chemotherapy improved OS and RFS more significantly in rectal cancer patients with positive surgical margin or PNI than in those with negative surgical margin and PNI.

Is short-course radiotherapy and total neoadjuvant therapy the new standard of care in locally advanced rectal cancer? A sensitivity analysis of the RAPIDO clinical trial

BACKGROUND

The results of the RAPIDO trial have been accepted as evidence in favour of short-course radiotherapy (SC-RT) followed by chemotherapy before total mesorectal excision in high-risk locally advanced rectal cancer. A noteworthy concern is that the RAPIDO trial did not ensure that all patients in the control arm received adjuvant chemotherapy. This may bias statistical estimates in favour of the experimental arm if adjuvant chemotherapy is active in rectal cancer. Moreover, the 5-year update revealed an increase in the risk of local relapse in the experimental arm.

MATERIALS AND METHODS

We carried out sensitivity analyses to determine how plausible effects of adjuvant chemotherapy, adjusted by the proportion of patients in the standard arm receiving adjuvant treatment, would have influenced the observed treatment effect estimate of the RAPIDO trial. The most plausible values for the benefit of adjuvant chemotherapy were determined by Bayesian re-analysis of a prior meta-analysis.

RESULTS

The meta-analysis suggested that oxaliplatin/fluorouracil-based adjuvant chemotherapy may improve disease-free survival (DFS) in rectal cancer although the signal is weak [hazard ratio (HR) 0.84, 95% credible interval, 0.57-1.15]; probability of benefit (HR <1) was 91.2%. In the sensitivity analysis, the HR for disease-related treatment failure would remain <1, thus favouring total neoadjuvant therapy (TNT), on most occasions, but the null hypothesis would not have been rejected in various credible settings. For the RAPIDO data to be consistent with the null effect, a moderate benefit of adjuvant chemotherapy (HR for DFS between 0.75 and 0.80) and 70%-80% of exposed participants would suffice.

CONCLUSION

The decision to make adjuvant chemotherapy optional in the standard arm may have biased the results in favour of the experimental arm, in a scenario in which TNT does not offset the increase in local recurrences after SC-RT.

A prognostic nomogram for stage II/III rectal cancer patients treated with neoadjuvant chemoradiotherapy followed by surgical resection

Background

The purpose of this study was to develop a large population-based nomogram incorporating the log odds of positive nodes (LODDS) for predicting the overall survival (OS) of stage II/III rectal cancer patients treated with neoadjuvant chemoradiotherapy (NCRT) followed by surgical resection.

Methods

The Surveillance, Epidemiology, and End Results database was used to collect information on patients diagnosed with stage II/III rectal cancer between 2010 and 2015 and treated with NCRT followed by surgical resection. The Cox regression analyses were performed to determine the independent prognostic factors. In this study, LODDS was employed instead of American Joint Committee on Cancer (AJCC) 7th N stage to determine lymph node status. Then a nomogram integrating independent prognostic factors was developed to predict the 24-, 36-, and 60-month overall survival. The receiver operating characteristic (ROC) curves and calibration curves were used to validate the nomogram. Furthermore, patients were stratified into three risk groups (high-, middle-, and low-risk) based on the total points obtained from the nomogram. And Kaplan–Meier curves were plotted to compare the OS of the three groups.

Results

A total of 3829 patients were included in the study. Race, sex, age, marital status, T stage, tumor grade, tumor size, LODDS, CEA level, and postoperative chemotherapy were identified as independent prognostic factors, based on which the prognostic nomogram was developed. The area under curve values of the nomogram for the 24-, 36-, and 60-month OS in the training cohort were 0.736, 0.720, and 0.688, respectively; and 0.691, 0.696, and 0.694 in the validation cohort, respectively. In both the validation and training cohorts, the calibration curves showed a high degree of consistency between actual and nomogram-predicted survival rates. The Kaplan–Meier curves showed that the three risk groups had significant differences in overall survival (P < 0.001).

Conclusion

A large population-based nomogram incorporating LODDS was developed to assist in evaluating the prognosis of stage II/III rectal cancer patients treated with NCRT followed by surgical resection. The nomogram showed a satisfactorily discriminative and stable ability to predict the OS for those patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01710-z.

Oncologic benefit of adjuvant chemotherapy for locally advanced rectal cancer after neoadjuvant chemoradiotherapy and curative surgery with selective lateral pelvic lymph node dissection: An international retrospective cohort study

INTRODUCTION

Intensive local treatment comprising total mesorectal excision (TME) with selective lateral pelvic lymph node dissection (LPND) after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) has received attention among clinicians treating rectal cancer. It remains unclear whether adjuvant chemotherapy (ACT) after intensive local treatment is beneficial for these patients. We evaluated the oncologic benefit of ACT for patients with LARC who received intensive local treatment.

MATERIALS AND METHODS

This international multicentre retrospective cohort study included 737 patients treated in Japan and Korea between 2010 and 2017. The effectiveness of ACT on recurrence-free survival (RFS) was evaluated using univariable and multivariable Cox proportional hazards models, with subgroup analyses to identify subpopulations potentially benefiting from ACT.

RESULTS

The median follow-up was 49 months; the 5-year RFS and local recurrence rates for the entire cohort were 72.1% and 4.9%, respectively; 514 patients (69.7%) received adjuvant chemotherapy, without an oncologic benefit (hazard ratio, 1.14; 95% confidence interval [CI]: 0.79-1.68) demonstrated in the multivariable Cox regression analysis. In subgroup analyses, the distributions of the 95% CI in patients aged ≥70 years and those with ypStage 0 tended to place a disproportionate emphasis that favoured the non-ACT treatment strategy.

CONCLUSION

Despite achieving good local control with intensive local treatment strategy, the effectiveness of ACT for the LARC patients with CRT followed by TME with selective LPND was not proved. Elderly patients and those with ypStage0 may not receive benefit from ACT after CRT and TME ± LPND.

Assessment of Textbook Oncologic Outcomes Following Proctectomy for Rectal Cancer

BACKGROUND

Outcomes of rectal adenocarcinoma vary considerably. Composite "textbook oncologic outcome" (TOO) is a single metric that estimates optimal clinical performance for cancer surgery.

METHODS

Patients with stage II/III rectal adenocarcinoma who underwent single-agent neoadjuvant chemoradiation and proctectomy within 5-12 weeks were identified in the National Cancer Database (NCDB). TOO was defined as achievement of negative distal and circumferential resection margin (CRM), retrieval of ≥ 12 nodes, no 90-day mortality, and length of stay (LOS) < 75th percentile of corresponding year's range. Multivariable logistic regression was used to identify predictors of TOO.

RESULTS

Among 318,225 patients, 8869 met selection criteria. Median age was 62 years (IQR 54-71), and 5550 (62.6%) were males. Low anterior resection was the most common procedure (LAR, 6,037 (68.1%) and 3084 (34.8%) were treated at a high-volume center (≥ 20 rectal resections/year). TOO was achieved in 3967 patients (44.7%). Several components of TOO were achieved commonly, including negative CRM (87.4%), no 90-day mortality (98.0%), no readmission (93.0%), and no prolonged hospitalization (78.8%). Logistic regression identified increasing age, non-private insurance, low-volume centers, open approach, Black race, Charlson score ≥ 3, and abdominoperineal resection (APR) as predictors of failure to achieve TOO. Over time, TOOs were attained more commonly which correlated with increased minimally invasive surgery (MIS) adoption. TOO achievement was associated with improved survival.

CONCLUSIONS

Rectal adenocarcinoma patients achieve TOO uncommonly. Treatment at high-volume centers and MIS approach were among modifiable factors associated with TOO in this study.

Multicenter, Randomized, Phase III Trial of Short-Term Radiotherapy Plus Chemotherapy Versus Long-Term Chemoradiotherapy in Locally Advanced Rectal Cancer (STELLAR)

PURPOSE

To ascertain if preoperative short-term radiotherapy followed by chemotherapy is not inferior to a standard schedule of long-term chemoradiotherapy in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

Patients with distal or middle-third, clinical primary tumor stage 3-4 and/or regional lymph node-positive rectal cancer were randomly assigned (1:1) to short-term radiotherapy (25 Gy in five fractions over 1 week) followed by four cycles of chemotherapy (total neoadjuvant therapy [TNT]) or chemoradiotherapy (50 Gy in 25 fractions over 5 weeks, concurrently with capecitabine [chemoradiotherapy; CRT]). Total mesorectal excision was undertaken 6-8 weeks after preoperative treatment, with two additional cycles of CAPOX (intravenous oxaliplatin [130 mg/m², once a day] on day 1 and capecitabine [1,000 mg/m², twice a day] from days 1 to 14) in the TNT group and six cycles of CAPOX in the CRT group. The primary end point was 3-year disease-free survival (DFS).

RESULTS

Between August 2015 and August 2018, a total of 599 patients were randomly assigned to receive TNT (n = 302) or CRT (n = 297). At a median follow-up of 35.0 months, 3-year DFS was 64.5% and 62.3% in TNT and CRT groups, respectively (hazard ratio, 0.883; one-sided 95% CI, not applicable to 1.11; P < .001 for noninferiority). There was no significant difference in metastasis-free survival or locoregional recurrence, but the TNT group had better 3-year overall survival than the CRT group (86.5% v 75.1%; P = .033). Treatment effects on DFS and overall survival were similar regardless of prognostic factors. The prevalence of acute grade III-V toxicities during preoperative treatment was 26.5% in the TNT group versus 12.6% in the CRT group (P < .001).

CONCLUSION

Short-term radiotherapy with preoperative chemotherapy followed by surgery was efficacious with acceptable toxicity and could be used as an alternative to CRT for locally advanced rectal cancer.

A practical framework for the targeted use of total neoadjuvant therapy for rectal cancer

Total neoadjuvant therapy (TNT) for rectal cancer is the preoperative delivery of radiation or chemoradiotherapy as well as systemic chemotherapy for the purpose of improving treatment completion rates and decreasing toxicity, maximizing the primary tumor response, and improving survival for patients with rectal cancer. This review summarizes the data surrounding TNT, including several recent randomized controlled trials. Moreover, it reviews the literature regarding high-quality surgery and the role of radiation and chemotherapy in the treatment of rectal cancer in the modern era. Finally, it presents an evidence-based protocol for the selective use of TNT in the treatment of patients with rectal cancer.

SEOM-GEMCAD-TTD clinical guidelines for localized rectal cancer (2021)

The management of localized rectal cancer requires a multidisciplinary approach to optimize outcomes, reduce morbidity and prevent under or overtreatments. While early stages may obtain benefit of local resections without any additional therapies, locally advanced rectal cancer becomes a challenge defining the better sequential strategy of surgery, radiotherapy and chemotherapy. The latest results of international phase III studies have positioned the total neoadjuvant therapy as a potential new standard of care in high risk rectal cancers, however, the best schedule is still not well defined.

The Evolving Neoadjuvant Treatment Paradigm for Patients with Locoregional mismatch Repair Proficient Rectal Cancer

OPINION STATEMENT

The standard of care for locally advanced rectal cancer (LARC) has included preoperative chemoradiation, total mesorectal excision surgery and post operative adjuvant chemotherapy based on histopathology. The current therapeutic landscape in LARC has many different options with different directions of travel - depending on the goal of treatment. Enthusiasm for delivering total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is increasing in the light of recently published randomised phase III trials - RAPIDO and PRODIGE-23. There is a wide diversity of different potential schedules and a multitude of approaches, which include induction neoadjuvant chemotherapy (NACT) with a range of chemotherapy options (CAPEOX, FOLFOX, FOLFOXIRI) and a varying duration of 6-18 weeks, or consolidation NACT. These schedules either precede or follow short-course preoperative radiation therapy (SCPRT) using 5 × 5Gy or long-course chemoradiation (LCCRT) using 45-60Gy respectively. The different strategies of induction and consolidation neoadjuvant chemotherapy have been compared and have similar long-term outcomes, but consolidation chemotherapy may facilitate organ-sparing. The results are driving novel paradigms with both intensification and de-intensification treatment strategies. The ideal combination, sequence or duration of such a TNT approach remains undefined. As yet, there are no robust clinical, genetic, molecular, immune or imaging features (alone or integrated), which either direct or aid these choices. Currently, the selection of neoadjuvant treatment is driven by the impact on avoidance or feasibility of surgery or reducing the risk of metastases rather than prevention of local recurrence. Most believe that TNT will improve overall survival, despite the present lack of evidence. Both the inherent heterogeneity in LARC and the observed range of different responses underline the need for response biomarkers to individually tailor therapy rather than 'a one size fits all' approach.

Cancer patient survival can be parametrized to improve trial precision and reveal time-dependent therapeutic effects

Individual participant data (IPD) from oncology clinical trials is invaluable for identifying factors that influence trial success and failure, improving trial design and interpretation, and comparing pre-clinical studies to clinical outcomes. However, the IPD used to generate published survival curves are not generally publicly available. We impute survival IPD from ~500 arms of Phase 3 oncology trials (representing ~220,000 events) and find that they are well fit by a two-parameter Weibull distribution. Use of Weibull functions with overall survival significantly increases the precision of small arms typical of early phase trials: analysis of a 50-patient trial arm using parametric forms is as precise as traditional, non-parametric analysis of a 90-patient arm. We also show that frequent deviations from the Cox proportional hazards assumption, particularly in trials of immune checkpoint inhibitors, arise from time-dependent therapeutic effects. Trial duration therefore has an underappreciated impact on the likelihood of success.

Analysis of more than 150 Phase 3 oncology clinical trials supports parametric statistical analysis, significantly increasing the precision of small early-phase trials and relating deviations from the Cox proportional hazards model to trial duration.

A Postsurgical Prognostic Nomogram for Locally Advanced Rectosigmoid Cancer to Assist in Patient Selection for Adjuvant Chemotherapy

Background

The perioperative treatment model for locally advanced rectosigmoid junction cancer (LARSC) has not been finalized; whether this model should refer to the treatment model for rectal cancer remains controversial.

Methods

We screened 10,188 patients with stage II/III rectosigmoid junction adenocarcinoma who underwent surgery between 2004 and 2016 from the National Cancer Institute Surveillance, Epidemiology, and End Results database. Among them, 4,960 did not receive adjuvant chemotherapy, while 5,228 did receive adjuvant chemotherapy. Propensity score matching was used to balance the two groups for confounding factors, and the Kaplan-Meier method and log-rank test were used for survival analysis. Cox proportional hazards regression analysis was used to identify independent prognostic factors and build a predictive nomogram of survival for LARSC. X-tile software was used to divide the patients into three groups (low, medium, and high) according to their risk scores. 726 patients in our hospital were included for external validation.

Results

LARSC patients did not show a benefit from neoadjuvant radiotherapy (P>0.05). After further excluding patients who received neoadjuvant radiotherapy, multivariate analysis found that age, grade, tumor size, T stage, and log odds of positive lymph nodes were independent prognostic factors for patients without adjuvant chemotherapy and were included in the nomogram. The C-index of the model was 0.690 (95% confidence interval: 0.668–0.712). We divided the patients into low, moderate, and high risk subgroups based on prediction scores of the nomogram. We found that adjuvant chemotherapy did not improve the prognosis of low risk patients, while moderate and high risk patients benefited from adjuvant therapy. External validation data found that moderate, and high risk patients also benefited from AT.

Conclusion

Direct surgery plus adjuvant chemotherapy may be the best perioperative treatment for LARSC. Moreover, adjuvant chemotherapy is only recommended for moderate and high risk patients as it did not benefit low risk patients.

Debating Pros and Cons of Total Neoadjuvant Therapy in Rectal Cancer

Simple Summary

Rectal cancers represent one third of all colorectal tumours. Patients diagnosed with localised colon cancer undergo surgery upfront, likely followed by adjuvant chemotherapy. Those diagnosed with localised rectal cancer, however, frequently benefit from neoadjuvant treatments with either radiotherapy or chemoradiotherapy before undergoing surgery. On the other hand, the benefit of adjuvant chemotherapy in this setting is more controversial. The main challenges in treating patients affected by rectal cancer encompass: decreasing the risks of local relapse and distant metastases, preserving the sphincter and minimising treatment-associated functional sequelae, and improving overall survival. Some of these fuelled the concept of total neoadjuvant therapy, namely giving all available treatments including radiotherapy and systemic chemotherapy before surgery. Here, we critically review the pros and cons of such a treatment strategy, but also discuss the biological rational to support neoadjuvant treatment intensification.

Abstract

Recently, two large, randomised phase III clinical trials of total neoadjuvant therapy (TNT) in locally advanced rectal cancer were published (RAPIDO and PRODIGE 23). These two trials compared short-course radiotherapy (SCRT) followed by chemotherapy with standard chemoradiotherapy (CRT) and chemotherapy followed by CRT with standard CRT, respectively. They showed improvement in some of the outcomes such as distant recurrence and pathological complete response (pCR). No improvement, however, was observed in local disease control or the de-escalation of surgical procedures. Although it seems lawful to integrate TNT within the treatment algorithm of localised stage II and III rectal cancer, many questions remain unanswered, including which are the optimal criteria to identify patients who are most likely to benefit from this intensive treatment. Instead of providing a sterile summary of trial results, we put these in perspective in a pros and cons manner. Moreover, we discuss some biological aspects of rectal cancer, which may provide some insights into the current decision-making process, and represent the basis for the future development of alternative, more effective treatment strategies.

Evaluating the benefit of adjuvant chemotherapy in patients with ypT0–1 rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND

Adjuvant chemotherapy (ACTx) is recommended in rectal cancer patients after preoperative chemoradiotherapy (PCRT), but its efficacy in patients in the early post-surgical stage who have a favorable prognosis is controversial.

AIM

To evaluate the long-term survival benefit of ACTx in patients with ypT0–1 rectal cancer after PCRT and surgical resection.

METHODS

We identified rectal cancer patients who underwent PCRT followed by surgical resection at the Asan Medical Center from 2005 to 2014. Patients with ypT0–1 disease and those who received ACTx were included. The 5-year overall survival (OS) and 5-year recurrence-free survival (RFS) were analyzed according to the status of the ACTx.

RESULTS

Of 520 included patients, 413 received ACTx (ACTx group) and 107 did not (no ACTx group). No significant difference was observed in 5-year RFS (ACTx group, 87.9% vs no ACTx group, 91.4%, P = 0.457) and 5-year OS (ACTx group, 90.5% vs no ACTx group, 86.2%, P = 0.304) between the groups. cT stage was associated with RFS and OS in multivariate analysis [hazard ratio (HR): 2.57, 95% confidence interval (CI): 1.07–6.16, P = 0.04 and HR: 2.27, 95%CI: 1.09–4.74, P = 0.03, respectively]. Furthermore, ypN stage was associated with RFS and OS (HR: 4.74, 95%CI: 2.39–9.42, P < 0.00 and HR: 4.33, 95%CI: 2.20–8.53, P < 0.00, respectively), but only in the radical resection group.

CONCLUSION

Oncological outcomes of patients with ypT0–1 rectal cancer who received ACTx after PCRT showed no improvement, regardless of the radicality of resection. Further trials are needed to evaluate the efficacy of ACTx in these group of patients.

Cost Effectiveness of Watch and Wait Versus Resection in Rectal Cancer Patients with Complete Clinical Response to Neoadjuvant Chemoradiation

BACKGROUND

Watch and wait (WW) protocols have gained increasing popularity for patients diagnosed with locally advanced rectal cancer and presumed complete clinical response after neoadjuvant chemoradiation. While studies have demonstrated comparable survival and recurrence rates between WW and radical surgery, the decision to undergo surgery has significant effects on patient quality of life. We sought to conduct a cost-effectiveness analysis comparing WW with abdominoperineal resection (APR) and low anterior resection (LAR) among patients with stage II/III rectal cancer.

METHODS

In this comparative-effectiveness study, we built Markov microsimulation models to simulate disease progression, death, costs, and quality-adjusted life-years (QALYs) for WW or APR/LAR. We assessed cost effectiveness using the incremental cost-effectiveness ratio (ICER), with ICERs under $100,000/QALY considered cost effective. Probabilities of disease progression, death, and health utilities were extracted from published, peer-reviewed literature. We assessed costs from the payer perspective.

RESULTS

WW dominated both LAR and APR at a willingness to pay (WTP) threshold of $100,000. Our model was most sensitive to rates of distant recurrence and regrowth after WW. Probabilistic sensitivity analysis demonstrated that WW was the dominant strategy over both APR and LAR over 100% of iterations across a range of WTP thresholds from $0-250,000.

CONCLUSIONS

Our study suggests WW could reduce overall costs and increase effectiveness compared with either LAR or APR. Additional clinical research is needed to confirm the clinical efficacy and cost effectiveness of WW compared with surgery in rectal cancer.

Can Elevated Pretreatment Serum Carcinoembryonic Antigen Levels Serve as a Potential Biomarker Guiding Adjuvant Chemotherapy in Rectal Cancer Patients With ypTis-3N0 After Neoadjuvant Radiotherapy and Surgery?

Survival benefit of adjuvant chemotherapy (ACT) remained controversial in patients with stage II/III rectal cancer (RC) who received neoadjuvant therapy and surgery. This study aimed to investigate the guiding role of elevated pretreatment serum carcinoembryonic antigen (CEA) levels for receiving ACT in yield pathological Tis-3N0 (ypTis-3N0) RC patients after neoadjuvant radiotherapy and surgery. Between 2004 and 2015, 10,973 RC patients with ypTis-3N0 who received neoadjuvant radiotherapy and radical surgery were retrospectively analyzed using the Surveillance, Epidemiology, and End Results (SEER) database. Compared with CEA-normal group, elevated-CEA patients had worse 5-year CSS rate (90.1 vs 83.5%). The 5-year CSS rates were 86.3 and 87.4% for ypTis-3N0M0 patients with or without ACT, respectively. Patients receiving ACT had a comparable 5-year CSS rate compared to those who did not regardless of CEA levels in ypTis-3N0M0 RC patients (CEA elevation group: 76.4 vs. 83.5%, P = 0.305; CEA normal group: 90.0 vs. 90.1%, P = 0.943). Intriguingly, ypT3N0M0 RC patients with elevated CEA levels may benefit from ACT (5-year CSS: 69.1 vs. 82.9%, P = 0.045), while those with normal CEA levels did not (5-year CSS: 89.3 vs. 89.3%, P = 0.885). Multivariate Cox analysis demonstrated that ACT tended to be a protective factor in elevated-CEA ypT3N0M0 RC patients (HR = 0.633, 95% CI = 0.344–1.164, P = 0.141), while ACT was not associated with improved CSS in normal-CEA ypT3N0M0 RC patients (HR = 1.035, 95% CI = 0.487–2.202, P = 0.928). Elevated pretreatment serum CEA levels may serve as a promising biomarker guiding ACT in rectal cancer patients with ypT3N0M0.

Recent advances in gastrointestinal cancers

Gastrointestinal cancers occur in a total of eight different locations, each of them with a different standard of care. This article is not an exhaustive review of what has been published in 2020. We have concentrated on the thirteen phase III randomized studies that are practice-changing. All these studies are oral presentations which have been given in one of the four major oncology congresses, namely American Society of Clinical Oncology (ASCO), ASCO gastrointestinal (GI), European Society of Medical Oncology (ESMO) and ESMO-GI. We provide a concise view of these major trials and their main outcomes, and put these results into context.

Tailored total neoadjuvant therapy for locally advanced rectal cancer: One size may not fit for all!

While current neoadjuvant protocols have proven benefits on local control for majority of patients with locally advanced rectal cancer, there are certain clinical conditions that require future advances for improving the outcomes. Total neoadjuvant therapy incorporates systemic chemotherapy planned within standard neoadjuvant protocols either before or after radiotherapy for locally advanced rectal cancer as a whole. Enhanced compliance with planned oncological therapy, tumour downstaging, administration of chemotherapy at the earliest time in the disease course to help assessing chemosensitivity are the proposed benefits of total neoadjuvant therapy in patients with locally advanced rectal cancer. Patient selection criteria for administration of total neoadjuvant therapy in the recent guidelines are unclear. Since current literature is inconclusive for the optimal sequence and type of radiotherapy and chemotherapy, premature incorporation of total neoadjuvant therapy for all locally advanced rectal cancers may result in overtreatment and subsequently toxicity. This article aims to discuss the current literature and to propose a future perspective by considering real-life scenarios reflecting patients' needs for treatment of locally advanced rectal cancer.

Current evidence regarding the role of adjuvant chemotherapy in rectal cancer patients with pathologic complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

PURPOSE

The aim of this meta-analysis was to investigate the role of adjuvant chemotherapy (AC) in rectal cancer patients with pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) and curative resection.

METHODS

This study was completed in accordance to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The electronic scholar databases (Medline, Web of Science, Scopus) were screened for eligible articles. The level of evidence (LoE) was assessed using the GRADE methodology.

RESULTS

Overall, 23 non-randomized studies and 17,406 patients were included in the present meta-analysis. Pooled comparisons confirmed that AC improved overall survival (HR: 0.68, p=0.0003), but not disease-free (p=0.22) and recurrence-free survival (p=0.39). However, the LoE for all outcomes was characterized as "very low," due to the absence of RCTs.

CONCLUSIONS

Considering the study limitations and the lack of randomized studies, further high-quality RCTs are required to confirm the findings of our study.

Oncological Outcomes of Pathological T1 Lower Rectal Cancer Patients With or Without Preoperative Chemoradiotherapy

BACKGROUND/AIM

It remains unclear whether rectal cancers down-staged by preoperative chemoradiotherapy (CRT) have similar prognoses to those of the same stage without preoperative CRT. We compared prognoses of pT1 rectal cancer patients stratified by preoperative CRT.

PATIENTS AND METHODS

We retrieved data of patients with pathological T1 rectal cancer between 2003 and 2020. Patients were divided into the "ypT1 group" who received preoperative CRT following surgery and the "pT1 group" who underwent surgery alone. Factors associated with relapse-free survival (RFS) were investigated.

RESULTS

Among 86 patients, ypT1 and pT1 groups comprised 18 and 68 patients, respectively. There was no significant difference in RFS between the groups (p=0.19). Tumor location within 5 cm from the anal verge was associated with recurrence (hazard ratio: 0.13, p=0.034).

CONCLUSION

The prognosis of patients with ypT1 rectal cancer was similar to that of patients with pT1. Low tumor location was a poor prognostic factor.

[Neoadjuvant treatment for rectal cancer]

The management of patients with locally advanced rectal cancer has improved significantly in the past few years with preoperative radiotherapy (RT) and total mesorectal excision. The rate of local recurrence is now around 5 % while the risk of metastatic recurrence has not been reduced which is about 30 %. The benefit of adjuvant chemotherapy remains questionable apart from patients with ypN+tumor after preoperative chemoradiotherapy (CRT) for whom FOLFOX is an option. In recent years, several therapeutic trials have evaluated the benefit of extending the time between the end of RT and surgery and/or the benefit of neoadjuvant chemotherapy, administered as induction (before RT) or in consolidation (after RT and before surgery). The first results of two positive phase 3 trials, PRODIGE 23 and RAPIDO, have been reported in 2020. The two regimens evaluated in these trials are markedly different but have shown that neoadjuvant chemotherapy significantly reduces the risk of distant metastasis. Current developments largely related to a de-escalation of therapy: organ conservation according to a "Watch and Wait" strategy or local resection of the scar, administration of neoadjuvant chemotherapy without RT. These therapeutic strategies have not yet been validated but should be in the news tomorrow. The purpose of this review is to present recent data reported in patients with locally advanced rectal cancer.