Short-course radiotherapy with consolidation chemotherapy versus conventionally fractionated long-course chemoradiotherapy for locally advanced rectal cancer: randomized clinical trial

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.

Network meta-analysis of RTCs for efficacy of neoadjuvant treatment in rectal cancer

BACKGROUND

This network meta-analysis examined the efficacy of different types of neoadjuvant therapy (NAT) for rectal cancer in improving clinical and pathologic outcomes.

METHODS

PRISMA-compliant systematic review of PubMed and Scopus including only randomized clinical trials comparing two or more NAT regimens for rectal cancer. A network meta-analysis was undertaken for the main outcomes, including pathological complete response (pCR), disease downstaging, R0 resection, permanent stoma, and major adverse effects. Risk of bias was assessed using the ROB-2 tool.

RESULTS

19 randomized controlled trials incorporating 7037 patients (62 % males) were included in the analysis. Compared to standard neoadjuvant chemoradiation (NCRT), consolidation total neoadjuvant therapy (TNT) (OR: 1.82, 95 % CI: 1.46-2.27; p < 0.001) and induction TNT (OR: 1.72, 95 % CI: 1.31-2.26; p < 0.001) had higher odds of achieving pCR. Induction TNT was also significantly associated with higher odds of major adverse effects than was NCRT (OR: 3.14, 95 % CI: 2.50-3.94; p < 0.0001). Compared to NCRT, long course chemotherapy significantly increased the odds of R0 resection (OR: 1.42, 95 % CI: 1.13-1.78; p = 0.002), while consolidation TNT significantly increased organ preservation rates (OR: 2.82, 95 % CI: 1.58-5.05; p < 0.001). Short course radiotherapy doubled the odds of positive circumferential resection margins (CRM) compared to NCRT (OR: 1.99, 95 % CI: 1.11-3.55; p = 0.02).

CONCLUSIONS

Consolidation and induction TNT were superior in achieving better pathological outcomes in rectal cancer, offering significant benefits over standard NCRT. However, they were associated with a higher risk of adverse effects. Conversely, short course radiotherapy was linked to higher rates of positive CRM.

No operation after short-course radiotherapy followed by consolidation chemotherapy in locally advanced rectal cancer (NOAHS-ARC): study protocol for a prospective, phase II trial

PURPOSE

Organ preservation through a watch-and-wait (W&W) strategy has become a viable option for select rectal cancer patients with clinical complete responses (cCR) to total neoadjuvant therapy (TNT). This approach limits the morbidity associated with multimodal treatment. However, the optimal treatment strategy and predictors of treatment response are still unresolved. Rectal cancer incidence is rising, particularly in developing countries, and the disease is a major public health concern in Chile. Prior to the no operation after short-course radiotherapy followed by consolidation chemotherapy in locally advanced rectal cancer (NOAHS-ARC) trial, TNT-based treatments and W&W programs had not been implemented in Chile.

METHODS/DESIGN

This single-arm, multicenter, phase II prospective trial, conducted in Santiago, Chile, will enroll patients with stage II/III rectal adenocarcinoma. Treatment involves induction short-course radiotherapy (25 Gy in 5 fractions) followed by consolidation chemotherapy (FOLFOX × 9 or CAPOX × 6 cycles). The response will be assessed 4-8 weeks after chemotherapy completion. Patients achieving cCR will be offered W&W, while those with incomplete responses will undergo total mesorectal excision. The primary endpoint is the rate of complete tumor response, combining pathologic complete responses (pCR) and sustained cCR (> 1 year), compared to a matched cohort treated with neoadjuvant chemoradiation alone. The trial aims to recruit 48 patients, assuming a combined pCR/sustained cCR rate of 12%. Quality of life measures will be assessed, and a biorepository of tissue and plasma samples will be established for future research, alongside serial endoscopic and MRI images.

DISCUSSION

NOAHS-ARC seeks to advance organ preservation strategies in rectal cancer while pioneering TNT and W&W protocols in Chile. The study will also focus on functional outcomes and provide valuable data for improving patient care both locally and globally.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04864067. Registered on April 28, 2021.

Quality Assurance in Radiotherapy (RT)-Specific Trials: Indian Scenario

AIMS

There is evidence that proper radiotherapy trial quality assurance (RTTQA) translates into improved outcomes for patients. However, the practice of RTTQA is heterogeneous and implemented in a diverse manner across trials. In this paper, we review the RTTQA report for randomised trials (RCT) conducted in India and present our experience with RTTQA for various clinical trials and highlight the key achievements and challenges.

MATERIALS AND METHODS

Search was performed using the keywords and the variations thereof for "radiotherapy" and author affiliations from India, its states and major metropolitan cities. Pubmed search filters were used to restrict results to RCT published in the past 5 years (2019-2024). Reporting of RTTQA procedures from publications and protocols was documented along with the protocol-specified dosimetric goals. We also evaluated a few clinical trials performed in the Department of Radiation Oncology at Tata Medical Center. The different RTTQA procedures and results for four representative clinical trials have been described.

RESULTS

A formal RTTQA process was reported by only one out of 24 randomised controlled trials and formal dosimetric goals were pre-specified by 9 of 13 trials where IMRT was used as treatment. RTTQA requirements were tailored for each clinical trial at Tata Medical Center. For the HYPORT trial, the RTTQA process focused on ensuring the matchline doses were homogenous. HYPORT B trial commissioned the use of a simultaneous integrated boost technique which emphasised conformal avoidance of dose spillage to contralateral breast and lung. HYPORT Adjuvant and PROPARA trials are multicentre clinical trials. While HYPORT Adjuvant focussed on ensuring that the dose delivery met the predefined constraints, segmentation of the target volume was important for the PROPARA trial.

CONCLUSION

We demonstrate different RTTQA procedures required for representative clinical trials and highlight key challenges encountered.

Total neoadjuvant therapy based on short-course radiotherapy versus standard long-course chemoradiotherapy for locally advanced rectal cancer: a systematic review and meta-analysis of randomized controlled trials

Background

We conducted the meta-analysis to compare the therapeutic effects of total neoadjuvant therapy (TNT) based on short-course radiotherapy followed by consolidation chemotherapy (SCRT/CCT) and long-course chemoradiotherapy (LCCRT) for locally advanced rectal cancer (LARC) according to certain significant randomized controlled trials (RCTs).

Methods

The researchers retrieved several databases, including PubMed, Embase, Web of Science, and the Cochrane Library, to collect all the relevant literature published since the establishment of the databases until July 30, 2024, and then screened to determine the qualified literature and extracted the relevant information. Finally, RevMan 5.4 software was utilized to conduct the meta-analysis for determining the 95% confidence interval (CI) and pooled risk ratio (RR). There were 9 study indicators, including the pathologic complete remission (pCR) rate, tumor downstaging rate, R0 resection rate, sphincter preservation rate, disease-free survival (DFS), overall survival (OS), acute ≥3 grade toxicity rate, surgery complication rate, and distant recurrence rate. When moderate, even severe, heterogeneity was found, a random-effect model was applied; otherwise, a fixed-effect model was used for the analysis.

Results

A total of 6 eligible RCTs and 2259 participants were included in this meta-analysis. Compared with the standard LCCRT, TNT treatment on the basis of SCRT/CCT increased the pCR rate significantly [RR = 1.67, 95% CI (1.36, 2.04), P < 0.00001], especially in ≥ 4 cycles of the CCT arm [RR = 1.77, 95% CI: (1.41-2.23), p < 0.00001], and led to a similar tumor downstaging rate [RR = 0.99, 95% CI (0.85, 1.15), P = 0.92]. Moreover, survival outcomes, distant recurrence rate, and surgical indicators were comparable between the two groups.

Conclusion

For LARC patients, the SCRT/CCT regimen not only has a higher pCR rate, equivalent OS, and comparable additional indicators versus standard LCCRT but also shortens the treatment time, costs less, and improves patients' adherence to the innovative anti-tumor therapy; hence, with the concept of acute toxicity control, it could be further widely and safely utilized, especially in resource-limited settings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024600180.

Organ preservation after neoadjuvant long-course chemoradiotherapy versus short-course radiotherapy

BACKGROUND

Potential differences in organ preservation between total neoadjuvant therapy (TNT) regimens integrating long-course chemoradiotherapy (LCCRT) and short-course radiotherapy (SCRT) in rectal cancer remain undefined.

PATIENTS AND METHODS

This natural experiment arose from a policy change in response to the COVID-19 pandemic during which our institution switched from uniformly treating patients with LCCRT to mandating that all patients be treated with SCRT. Our study includes 323 locally advanced rectal adenocarcinoma patients treated with LCCRT-based or SCRT-based TNT from January 2018 to January 2021. Patients who achieved clinical complete response were offered organ preservation with watch-and-wait (WW) management. The primary outcome was 2-year organ preservation. Additional outcomes included local regrowth, distant recurrence, disease-free survival (DFS), and overall survival (OS).

RESULTS

Patient and tumor characteristics were similar between LCCRT (n = 247) and SCRT (n = 76) cohorts. Median follow-up was 31 months. Similar clinical complete response rates were observed following LCCRT and SCRT (44.5% versus 43.4%). Two-year organ preservation was 40% [95% confidence interval (CI) 34% to 46%] and 31% (95% CI 22% to 44%) among all patients treated with LCCRT and SCRT, respectively. In patients managed with WW, LCCRT resulted in higher 2-year organ preservation (89% LCCRT, 95% CI 83% to 95% versus 70% SCRT, 95% CI 55% to 90%; P = 0.005) and lower 2-year local regrowth (19% LCCRT, 95% CI 11% to 26% versus 36% SCRT, 95% CI 16% to 52%; P = 0.072) compared with SCRT. The 2-year distant recurrence (10% versus 6%), DFS (90% versus 90%), and OS (99% versus 100%) were similar between WW patients treated with LCCRT and SCRT, respectively.

CONCLUSIONS

While WW eligibility was similar between cohorts, WW patients treated with LCCRT had higher 2-year organ preservation and lower local regrowth than those treated with SCRT, yet similar DFS and OS. These data support induction LCCRT followed by consolidation chemotherapy as the preferred TNT regimen for patients with locally advanced rectal cancer pursuing organ preservation.

Treatment of Locally Advanced Rectal Cancer in the Era of Total Neoadjuvant Therapy: A Systematic Review and Network Meta-Analysis

Importance

Treatment of locally advanced rectal cancer (LARC) involves neoadjuvant chemoradiotherapy plus total mesorectal excision and adjuvant chemotherapy. However, total neoadjuvant therapy (TNT) protocols (ie, preoperative chemotherapy in addition to radiotherapy) may allow better adherence and early treatment of distant micrometastases and may increase pathological complete response (pCR) rates.

Objective

To assess the efficacy and tolerability of TNT protocols for LARC.

Data Sources

MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection electronic databases and ClinicalTrials.gov for unpublished studies were searched from inception to March 2, 2024.

Study Selection

Randomized clinical trials including adults with LARC who underwent rectal resection as a final treatment were included. Studies including nonoperative treatment (watch-and-wait strategy), treatments other than rectal resection, immunotherapy, or antiangiogenic agents were excluded. Among the initially identified studies, 2.9% met the selection criteria.

Data Extraction and Synthesis

Two authors independently screened the records and extracted data. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)-compliant pairwise and network meta-analyses with a random-effects model were performed in a frequentist framework, and the certainty of evidence was assessed according to the confidence in network meta-analysis approach.

Main Outcomes and Measures

The primary outcome was pCR, defined as the absence of residual tumor at pathological assessment after surgery. Secondary outcomes included tolerability, toxic effects, perioperative outcomes, and long-term survival.

Results

Of 925 records identified, 27 randomized clinical trials, including 13 413 adults aged 18 years or older (median age, 60.0 years [range, 42.0-63.5 years]; 67.2% male) contributed to the primary network meta-analysis. With regard to pCR, long-course chemoradiotherapy (L-CRT) plus consolidation chemotherapy (relative risk [RR], 1.96; 95% CI, 1.25-3.06), short-course radiotherapy (S-RT) plus consolidation chemotherapy (RR, 1.76; 95% CI, 1.34-2.30), and induction chemotherapy plus L-CRT (RR, 1.57; 95% CI, 1.09-2.25) outperformed standard L-CRT with single-agent fluoropyrimidine-based chemotherapy. Considering 3-year disease-free survival, S-RT plus consolidation chemotherapy (RR, 1.08; 95% CI, 1.01-1.14) and induction chemotherapy plus L-CRT (RR, 1.12; 95% CI, 1.01-1.24) outperformed L-CRT, in spite of an increased 5-year locoregional recurrence rate of S-RT plus consolidation chemotherapy (RR, 1.65; 95% CI, 1.03-2.63).

Conclusions and Relevance

In this systematic review and network meta-analysis, 3 TNT protocols were identified to outperform the current standard of care in terms of pCR rates, with good tolerability and optimal postoperative outcomes, suggesting they should be recognized as first-line treatments.

Surgical Outcomes in Total Neoadjuvant Therapy for Rectal Cancer Versus Standard Long-course Chemoradiation: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This systematic review and meta-analysis seeks to evaluate the impact of total neoadjuvant therapy (TNT) for rectal cancers on surgical complications and surgical pathology when compared with standard long-course chemoradiotherapy (LCRT).

BACKGROUND

The oncological benefits of TNT are well published in previous meta-analyses, but there is little synthesized information on how it affects surgical outcomes. A recent study has suggested an increase in local recurrence and higher rates of breached total mesorectal excision (TME) plane in TNT patients.

METHODS

This study conformed to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A search was performed in Medline (via PubMed), Cochrane databases, EMBASE and CINAHL to identify relevant randomized controlled trials (RCTs) comparing outcomes between TNT and LCRT. Meta-analyses of pooled proportions between TNT and LCRT were performed, comparing primary outcomes of surgical mortality, morbidity and all reported complications; surgical-pathology differences, namely mesorectal quality, R0 resection rates, circumferential resection margin positive rates, and sphincter preservation rates. Death and progression of disease during neoadjuvant treatment period was also compared. Risk of bias of RCTs was performed using the Cochrane risk-of-bias tool by 2 independent reviewers.

RESULTS

A total of 3185 patients with rectal cancer from 11 RCTs were included in the analysis: 1607 received TNT and 1578 received LCRT, of which 1422 (TNT arm) and 1391 (LCRT arm) underwent surgical resection with curative intent. There was no significant difference in mortality [risk ratio (RR)=0.86, 95% CI: 0.13-5.52, P =0.88, I2 =52%] or major complications (RR=1.04, 95% CI: 0.86-1.26, P =0.70, I2 =0%) between TNT and LCRT. There was a significantly higher risk of breached TME in TNT group on pooled analysis (RR=1.49, 95% CI: 1.03-12.16, P =0.03, I2 =0%), and on subgroup analysis there is higher risk of breached TME in those receiving extended duration of neoadjuvant treatment (>17 weeks from start of treatment to surgery) when compared with LCRT (RR=1.61, 95% CI: 1.06-2.44, P =0.03). No difference in R0 resection rates (RR=0.85, 95% CI: 0.66-1.10, P =0.21, I2 =15%), circumferential resection margin positive rates (RR=0.87, 95% CI: 0.65-1.16, P =0.35, I2 =10%) or sphincter preservation rates (RR=1.02, 95% CI: 0.83-1.25, P =0.88, I2 =57%) were observed. There was a significantly lower risk of progression of disease to an unresectable stage during the neoadjuvant treatment period in TNT patients (RR=0.60, 95% CI: 0.39-0.92, P =0.03, I2 =18%). On subgroup analysis, it appears to favor those receiving extended duration of neoadjuvant treatment (RR=0.44, 95% CI: 0.26-0.80, P =0.002), and those receiving induction-type chemotherapy in TNT (RR=0.25, 95% CI: 0.07-0.88, P =0.03).

CONCLUSIONS

TNT increases rates of breached TME which can contribute to higher local recurrence rates. TNT, however, improves systemic control by reducing early progression of disease during neoadjuvant treatment period. Further research is warranted to identify patients that will benefit from this strategy.

Radiotherapy in the preoperative neoadjuvant treatment of locally advanced rectal cancer

Radiotherapy and chemotherapy are effective treatments for patients with locally advanced rectal cancer (LARC) and can significantly improve the likelihood of R0 resection. Radiotherapy can be used as a local treatment to reduce the size of the tumor, improve the success rate of surgery and reduce the residual cancer cells after surgery. Early chemotherapy can also downgrade the tumor and eliminate micrometastases throughout the body, reducing the risk of recurrence and metastasis. The advent of neoadjuvant concurrent radiotherapy (nCRT) and total neoadjuvant treatment (TNT) has brought substantial clinical benefits to patients with LARC. Even so, given increasing demand for organ preservation and quality of life and the disease becoming increasingly younger in its incidence profile, there is a need to further explore new neoadjuvant treatment options to further improve tumor remission rates and provide other opportunities for patients to choose watch-and-wait (W&W) strategies that avoid surgery. Targeted drugs and immunologic agents (ICIs) have shown good efficacy in patients with advanced rectal cancer but have not been commonly used in neoadjuvant therapy for patients with LARC. In this paper, we review several aspects of neoadjuvant therapy, including radiation therapy and chemotherapy drugs, immune drugs and targeted drugs used in combination with neoadjuvant therapy, with the aim of providing direction and thoughtful perspectives for LARC clinical treatment and research trials.

Total neoadjuvant therapy versus standard neoadjuvant treatment strategies for the management of locally advanced rectal cancer: network meta-analysis of randomized clinical trials

BACKGROUND

This study compared the advantages and disadvantages of total neoadjuvant therapy (TNT) strategies for patients with locally advanced rectal cancer, compared with the more traditional multimodal neoadjuvant management strategies of long-course chemoradiotherapy (LCRT) or short-course radiotherapy (SCRT).

METHODS

A systematic review and network meta-analysis of exclusively RCTs was undertaken, comparing survival, recurrence, pathological, radiological, and oncological outcomes. The last date of the search was 14 December 2022.

RESULTS

In total, 15 RCTs involving 4602 patients with locally advanced rectal cancer, conducted between 2004 and 2022, were included. TNT improved overall survival compared with LCRT (HR 0.73, 95 per cent credible interval 0.60 to 0.92) and SCRT (HR 0.67, 0.47 to 0.95). TNT also improved rates of distant metastasis compared with LCRT (HR 0.81, 0.69 to 0.97). Reduced overall recurrence was observed for TNT compared with LCRT (HR 0.87, 0.76 to 0.99). TNT showed an improved pCR compared with both LCRT (risk ratio (RR) 1.60, 1.36 to 1.90) and SCRT (RR 11.32, 5.00 to 30.73). TNT also showed an improvement in cCR compared with LCRT (RR 1.68, 1.08 to 2.64). There was no difference between treatments in disease-free survival, local recurrence, R0 resection, treatment toxicity or treatment compliance.

CONCLUSION

This study provides further evidence that TNT has improved survival and recurrence benefits compared with current standards of care, and may increase the number of patients suitable for organ preservation, without negatively influencing treatment toxicity or compliance.

Total neoadjuvant therapy in rectal cancer: a network meta-analysis of randomized trials

PURPOSE

To assess the efficacy of total neoadjuvant therapy (TNT) for rectal carcinoma in comparison with conventional chemoradiotherapy (CRT).

METHODS

A systematic review was performed according to the PRISMA guidelines. A Bayesian network meta-analysis was done using NetMetaXL and WinBUGS. This study was registered in PROSPERO on March 3, 2022 (No. CRD-42022307867).

RESULTS

Outcomes of 2,719 patients from 10 randomized trials between 2010 and 2022 were selected. Of these 1,191 (44%) had conventional long-course CRT (50-54 Gy) and capecitabine, 506 (18%) had induction chemotherapy followed by CRT (50-54 Gy) and capecitabine (iTNT), 230 (9%) had long-course CRT (50-54 Gy) followed by consolidation chemotherapy (cTNT), and 792 (29%) undergone modified short-course radiotherapy (25 Gy) with subsequent chemotherapy (mTNT). Total pathologic complete response (pCR) was 20% in the iTNT group, 21% in the mTNT group, 22% in the cTNT group, and 12% in the CRT group. Statistically significant difference in pCR rates was detected when comparing iTNT with CRT (odds ratio [OR], 1.76; 95% credible interval [CrI], 1.06-2.8), mTNT with CRT (OR, 1.90; 95% CrI, 1.25-2.74), and cTNT with CRT groups (OR, 2.54; 95% CrI, 1.26-5.08). No differences were found in R0 resection rates. No significant difference was found in long-term outcomes.

CONCLUSION

The early administration of systemic chemotherapy in the TNT regimen has improved short-term outcomes, though long-term results are underreported. Randomized trials with survival as the endpoint are necessary to evaluate the possible advantages of TNT modes.

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.

Radioimmunotherapy in colorectal cancer treatment: present and future

Colorectal cancer (CRC) is a deadly form of cancer worldwide. Patients with locally advanced rectal cancer and metastatic CRC have a poor long-term prognosis, and rational and effective treatment remains a major challenge. Common treatments include multi-modal combinations of surgery, radiotherapy, and chemotherapy; however, recurrence and metastasis rates remain high. The combination of radiotherapy and immunotherapy (radioimmunotherapy [RIT]) may offer new solutions to this problem, but its prospects remain uncertain. This review aimed to summarize the current applications of radiotherapy and immunotherapy, elaborate on the underlying mechanisms, and systematically review the preliminary results of RIT-related clinical trials for CRC. Studies have identified several key predictors of RIT efficacy. Summarily, rational RIT regimens can improve the outcomes of some patients with CRC, but current study designs have limitations. Further studies on RIT should focus on including larger sample sizes and optimizing the combination therapy regimen based on underlying influencing factors.

Short-Course Radiotherapy Followed by Consolidation Chemotherapy Is Safe and Effective in Locally Advanced Rectal Cancer: Comparative Short-term Results of Multicenter Propensity Score Case-Matched Study

BACKGROUND

Consolidation chemotherapy strategies have demonstrated improved pathological complete response and tumor downstaging rates for patients diagnosed with rectal cancer.

OBJECTIVE

This study aimed to compare perioperative outcomes and pathological complete response rates among different neoadjuvant treatment strategies in patients undergoing total mesorectal excision for locally advanced rectal cancer.

DESIGN

Propensity score case-matched study.

SETTING

High-volume tertiary care centers.

PATIENTS

Consecutive patients undergoing curative total mesorectal excision between January 2014 and June 2021 were queried.

INTERVENTIONS

Patients were divided into 3 groups: long-course chemoradiation therapy with (N = 128) or without (N = 164) consolidation chemotherapy or short-course radiotherapy (N = 53) followed by consolidation chemotherapy.

MAIN OUTCOME MEASURES

Demographics, preoperative tumor characteristics, histopathologic outcomes, and postoperative complication rates were reviewed and compared. Propensity score match analysis was conducted.

RESULTS

A total of 345 patients (mean age: 58 ± 12 years; female: 36%) met the study inclusion criteria. Time interval from neoadjuvant treatment until surgery was longer for patients receiving consolidation chemotherapy ( p < 0.001). Pathological complete response rates were comparable among patients receiving long-course chemoradiation therapy (20.3%) and short-course radiotherapy with consolidation chemotherapy (20.8%) compared to long-course chemoradiation therapy alone (14.6%) ( p = 0.36). After the propensity score case-matched analysis, 48 patients in the long-course chemoradiation therapy with consolidation chemotherapy group were matched to 48 patients in the short-course radiotherapy with consolidation chemotherapy group. Groups were comparable with respect to age, sex, clinical stage, tumor location, type of surgical approach, and technique. Pathological complete response rate was comparable between the groups (20.8% and 18.8%, p = 0.99).

LIMITATIONS

Study was limited by its retrospective nature.

CONCLUSIONS

Among recent neoadjuvant treatment modalities, pathological complete response rates, and short-term clinical outcomes were comparable. Short-course radiotherapy with consolidation chemotherapy is safe and effective as long-course chemoradiation therapy as in a short-term period. See Video Abstract at http://links.lww.com/DCR/C174 .

LA RADIOTERAPIA DE CORTA DURACIN SEGUIDA DE QUIMIOTERAPIA DE CONSOLIDACIN ES SEGURA Y EFICAZ EN EL CNCER DE RECTO LOCALMENTE AVANZADO RESULTADOS COMPARATIVOS A CORTO PLAZO DEL ESTUDIO MULTICNTRICO DE CASOS EMPAREJADOS POR PUNTAJE DE PROPENSION

ANTECEDENTES: Las estrategias de quimioterapia de consolidación han demostrado una mejor respuesta patológica completa y tasas de reducción del estadio del tumor para pacientes diagnosticados con cáncer de recto.OBJETIVO: Comparar los resultados perioperatorios y las tasas de respuesta patológica completa entre diferentes estrategias de tratamiento neoadyuvante en pacientes sometidos a escisión mesorrectal total por cáncer de recto localmente avanzado.DISEÑO: Estudio de casos emparejados por puntaje de propensión.ENTORNO CLINICO: Centros de atención terciaria de alto volumen.PACIENTES: Pacientes consecutivos sometidos a escisión mesorrectal total curativa por cáncer de recto localmente avanzado entre enero de 2014 y junio de 2021.INTERVENCIONES: Los pacientes se dividieron en tres grupos según la modalidad de tratamiento neoadyuvante: quimiorradioterapia de ciclo largo con (N = 128) o sin (N = 164) quimioterapia de consolidación o radioterapia de ciclo corto (N = 53) seguida de quimioterapia de consolidación.PRINCIPALES MEDIDAS DE RESULTADO: El punto final primario fue la respuesta patológica completa. Se revisaron y compararon los datos demográficos, las características preoperatorias del tumor, los resultados histopatológicos y las tasas de complicaciones posoperatorias entre los grupos de estudio. Se realizó un análisis de casos emparejados por puntaje de propensión.RESULTADOS: Un total de 345 pacientes (edad media de 58 ± 12 años y mujeres: 36%) cumplieron los criterios de inclusión del estudio. El intervalo de tiempo desde el tratamiento neoadyuvante hasta la cirugía fue mayor para los pacientes que recibieron quimioterapia de consolidación ( p < 0,001). Las tasas de respuesta patológica completa fueron comparables entre los pacientes que recibieron quimiorradioterapia de larga duración con quimioterapia de consolidación (20,3 %) y radioterapia de corta duración con quimioterapia de consolidación (20,8%) en comparación con la quimiorradiación de larga duración sola (14,6%) ( p = 0,36). Después del análisis de casos emparejados por puntaje de propensión, 48 pacientes en el grupo de quimiorradioterapia de ciclo largo con quimioterapia de consolidación se emparejaron con 48 pacientes en el grupo de radioterapia de ciclo corto con quimioterapia de consolidación. Los grupos fueron comparables con respecto a la edad, sexo, estadio clínico, ubicación del tumor, tipo de abordaje quirúrgico y la técnica. La tasa de respuesta patológica completa fue comparable entre los grupos (20,8% y 18,8%, p = 0,99). La morbilidad postoperatoria a los 30 días y las tasas de fuga anastomótica fueron similares.LIMITACIONES: El estudio estuvo limitado por su naturaleza retrospectiva.CONCLUSIONES: Entre las modalidades de tratamiento neoadyuvante recientes, las tasas de respuesta patológica completa y los resultados clínicos a corto plazo fueron comparables. La radioterapia de corta duración con quimioterapia de consolidación es segura y eficaz como terapia de quimiorradioterapia de larga duración en un período corto. Consulte Video Resumen en http://links.lww.com/DCR/C174 . (Traducción-Dr. Fidel Ruiz Healy ).

Selecting a TNT Schedule in Locally Advanced Rectal Cancer: Can We Predict Who Actually Benefits?

Many consider the standard of care for locally advanced rectal cancer (LARC) to be preoperative chemoradiotherapy, radical surgery involving a total mesorectal excision, and post-operative adjuvant chemotherapy based on the pathology of the specimen. The poor impact on distant control is a major limitation of this strategy, with metastasis rates remaining in the 25-35% range and recovery after radical surgery leading to reluctance with prescription and inconsistent patient compliance with adjuvant chemotherapy. A second limitation is the low rate of pathologic complete response (pCR) (around 10-15%) despite multiple efforts to potentiate preoperative chemoradiation regimens, which in turn means it is less effective at achieving non-operative management (NOM). Total neoadjuvant treatment (TNT) is a pragmatic approach to solving these problems by introducing systemic chemotherapy at an early timepoint. Enthusiasm for delivering TNT for patients with LARC is increasing in light of the results of published randomized phase III trials, which show a doubling of the pCR rate and a significant reduction in the risk of subsequent metastases. However, there has been no demonstrated improvement in quality of life or overall survival. A plethora of potential chemotherapy schedules are available around the radiotherapy component, which include preoperative induction or consolidation with a range of options (FOLFOXIRI, FOLFOX, or CAPEOX,) and a varying duration of 6-18 weeks, prior to long course chemoradiation (LCCRT) or consolidation NACT following short-course preoperative radiation therapy (SCPRT) using 5 × 5 Gy or LCCRT using 45-60 Gy, respectively. The need to maintain optimal local control is a further important factor, and preliminary data appear to indicate that the RT schedule remains a crucial issue, especially in more advanced tumors, i.e., mesorectal fascia (MRF) invasion. Thus, there is no consensus as to the optimum combination, sequence, or duration of TNT. The selection of patients most likely to benefit is challenging, as clear-cut criteria to individuate patients benefiting from TNT are lacking. In this narrative review, we examine if there are any necessary or sufficient criteria for the use of TNT. We explore potential selection for the individual and their concerns with a generalized use of this strategy.

Watch and Wait Approach for Rectal Cancer

The administration of neoadjuvant chemoradiotherapy (nCRT) followed by total mesorrectal excision (TME) and selective use of adjuvant chemotherapy can still be considered the standard of care in locally advanced rectal cancer (LARC). However, avoiding sequelae of TME and entering a narrow follow-up program of watch and wait (W&W), in select cases that achieve a comparable clinical complete response (cCR) to nCRT, is now very attractive to both patients and clinicians. Many advances based on well-designed studies and long-term data coming from big multicenter cohorts have drawn some important conclusions and warnings regarding this strategy. In order to safely implement W&W, it is important consider proper selection of cases, best treatment options, surveillance strategy and the attitudes towards near complete responses or even tumor regrowth. The present review offers a comprehensive overview of W&W strategy from its origins to the most current literature, from a practical point of view focused on daily clinical practice, without losing sight of the most important future prospects in this area.

Efficacy and safety of total neoadjuvant therapy in locally advanced rectal cancer: a meta-analysis

PURPOSE

The standard of care for locally advanced rectal cancer (LARC) has changed from a single radical surgical treatment to the current multimodality treatment (standard chemoradiotherapy (CRT) and total neoadjuvant therapy (TNT)). The efficacy and safety of both TNT and standard CRT are evaluated in randomized controlled trials (RCTs).

METHODS

RCTs were comprehensively searched in Chinese and English electronic databases. The experimental and control groups were TNT and the standard CRT, respectively, included in this meta-analysis. The outcomes were assessed through a fixed-effect or random-effect model of pooled odds (OR) or hazard ratios (HR).

RESULTS

Eleven RCTs, involving 3,101 patients were included in the final analysis. TNT showed increase in the pathological complete response (pCR) (OR = 1.95, 95% confidence interval (CI): 1.57-2.41; P < 0.05) and the R0 resection (OR = 1.19, 95% CI: 0.99-1.43; P = 0.062). There was no significant difference in local recurrence-free survival (LRFS) (HR = 0.97, P = 0.803), but TNT had better 3-year disease-free survival (DFS) (HR = 0.82, 95% CI: 0.72-0.93, P < 0.05), overall survival (OS) (HR = 0.87, 95% CI: 0.74-1.02, P = 0.08) and distant metastasis-free survival (DMFS) (HR = 0.79, 95% CI: 0.67-0.93, P < 0.05) than standard CRT.

CONCLUSIONS

TNT was safe and feasible as it improved pCR and survival outcomes, and reduced the risk of distant metastasis compared with standard CRT. TNT may be a superior strategy for LARC, but more RCTs are needed to prove it.

REGISTRATION AND PROTOCOL

PROSPERO CRD42022327697. We added the Chinese database after registration because of the inclusion of fewer RCTs www.crd.york.ac.uk/PROSPERO/ .

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.

Clinical benefits of oral capecitabine over intravenous 5-fluorouracyl regimen in case of neoadjuvant chemoradiotherapy followed by surgery for locally advanced rectal cancer

Background: During the last decade, one of the most important treatment options for locally advanced, potencially resectable rectal tumours was neoadjuvant chemoradiotherapy (CRT) followed by surgery. Methods: Effects of the neoadjuvant treatment on surgical outcomes were retrospectively analysed in 185 patients with stage T2-T4 and N0-2, resectable rectal tumour among two patient groups defined by radiosensitizer agents. Group 1 (n = 94) involved radiotherapy (RT) with 50.4 Gy total dose (25 × 1.8 Gy + 3 × 1.8 Gy tumour bed boost), and intravenous 5-fluorouracil (5-FU) (350 mg/m²) with leucovorin (20 mg/m²) on the 1-5 and 21-25 days, while Group 2 (n = 91) RT and orally administrated capecitabine (daily 2 × 825 mg/m²) on RT days. Surgery was carried out after 8-10 weeks. Side effects, perioperative complications, type of surgery, number of removed regional lymph nodes, resection margins and tumour regression grade (TRG) were analysed. Results: More favourable side effects were observed in Group 2. Despite the same rate of diarrhoea (Group 1 vs. Group 2: 54.3% vs. 56.0%), Grade 2-3 diarrhoea ratio was lower (p = 0.0352) after capecitabine (Group 2). Weight loss occurred in 17.0% and 2.2% (p = 0.00067), while nausea and vomiting was described in 38.3% and 15.4% (p = 0.00045) with 5-FU treatment and capecitabine respectively. Anaemia was observed in 33.0% and 22.0% (p = 0.0941). Complete tumour regression occurred in 25.3% after oral- and 13.8% after intravenous treatment (p = 0.049). Ratio of sphincter preservation was higher with laparoscopy than open surgery (72.3% vs. 39.7%) (p = 0.00001). Conclusion: The study confirms advantages of neoadjuvant chemoradiotherapy with oral capecitabine for rectal tumours, such as more favourable side effect profile and overall clinical outcome, with increased rate of complete tumour regression.

Total neoadjuvant therapy or standard chemoradiotherapy for locally advanced rectal cancer: A systematic review and meta-analysis

Background and Aim

The effectiveness of total neoadjuvant therapy (TNT) on patients with locally advanced rectal cancer (LARC) is controversy. This study aims to compare the prognostic value of TNT with standard neoadjuvant chemoradiotherapy (CRT) for LARC.

Methods

We searched databases (Embase [Ovid], Medline [Ovid], PubMed, Cochrane Library, and Web of Science) for articles published between January 1, 2000, and March 10, 2022. Studies on evaluating the effects of TNT and standard CRT on the prognosis of LARC were included. The primary outcomes were overall survival (OS) and disease-free survival (DFS).

Results

19 primary studies, involving 10 randomized controlled trials, 3 prospective studies and 6 retrospective studies, with data on 5,074 patients treated for LARC were included in the meta-analysis. Statistical analyses revealed that, compared with standard CRT, TNT significantly improved OS (hazard ratio [HR]=0.77, 95% confidence interval [CI]=0.65–0.90, I² = 30%, P = 0.17), DFS (HR = 0.85, 95% CI = 0.74–0.97, I² = 11%, P = 0.35), distant metastases-free survival (DMFS, HR = 0.76, 95% CI = 0.65–0.90, I² = 0%, P = 0.50), pathological complete response rate (pCR, OR = 1.89, 95% CI = 1.61–2.22, I² = 0%, P = 0.47), and R0 resection rate (OR = 1.33, 95% CI = 1.07–1.67, I² = 16%, P = 0.28), but local recurrence-free survival (LRFS, HR = 1.12, 95% CI = 0.90–1.39, I² = 4%, P = 0.37).

Conclusions

Comprehensive literature research shows that TNT showed excellent short-term efficacy in terms of pCR and R0 resection rate while also improved the long-term outcomes of OS, DFS and DMFS, might become a new standard of treatment in patients with LARC. Even so, more studies and longer follow-up were still warranted.

Tegafur-Uracil/Leucovorin Plus Oxaliplatin (TEGAFOX) as Consolidation Regimen after Short-Course Radiotherapy Is Effective for Locally Advanced Rectal Cancer

This study aimed to explore the safety and efficacy of neoadjuvant SCRT and tegafur−uracil/leucovorin plus oxaliplatin (TEGAFOX) for LARC in comparison to those of the modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX-6) regimen. We retrospectively evaluated 15 and 22 patients with LARC who underwent SCRT, followed by consolidation chemotherapy with TEGAFOX and mFOLFOX-6 before surgery, respectively, between January 2015 and December 2019. The primary endpoint was the tumor response rate. The secondary endpoints were compliance, toxicity, complications, overall survival (OS), and disease-free survival (DFS). The dose reduction rate was lower in the TEGAFOX group (0 vs. 9.1% (n = 2)). No grade III-IV toxicities occurred in the TEGAFOX group. Two and four patients in the TEGAFOX and mFOLFOX-6 groups, respectively, achieved clinical complete responses. The pathologic complete response rate was lower in the TEGAFOX group (7.7% vs. 17.6%). Overall, 11 (73.3%) and 17 (81.0%) patients had a neoadjuvant rectal (NAR) score of <16 in the TEGAFOX and mFOLFOX-6 groups, respectively. All patients in this study received sphincter-preservation surgery. One patient in each group developed Clavien−Dindo grade III complications. There were no significant between-group differences in the 3-year OS (81.8% vs. 84.8%, p = 0.884) and 3-year DFS (72% vs. 71.6%, p = 0.824) rates. TEGAFOX, as consolidation chemotherapy after SCRT, achieves good tumor downstaging and patient compliance in LARC. The toxicity, complications, and surgical outcomes are similar to those of mFOLFOX-6. Thus, TEGAFOX can be considered a chemotherapy option for rectal cancer treatment.

Neoadjuvant Short-Course Radiotherapy Followed by Consolidation Chemotherapy before Surgery for Treating Locally Advanced Rectal Cancer: A Systematic Review and Meta-Analysis

Neoadjuvant short course radiotherapy (SCRT) followed by consolidation chemotherapy (CCT) is an alternative treatment for locally advanced rectal cancer (LARC). We performed this systematic review and meta-analysis to explore the tumor response and oncological outcomes of this new approach compared to conventional chemoradiotherapy (CRT). An online search of the PubMed, Embase, and Cochrane Library databases was performed. This review included 7507 patients from 14 different cohorts. The pCR rate was higher with SCRT + CCT than that with CRT (RR: 1.60; 95% CI: 1.35−1.91; p < 0.01). SCRT + CCT provided a higher ypN0 response (RR: 1.06; 95% CI: 1.01−1.12; p = 0.02). There were no differences in R0 resection and positive CRM rates; however, more sphincter-preservation surgeries were performed in the SCRT + CCT arm (RR: 1.06; 95% CI: 1.01−1.11; p = 0.02). There was no difference in the OS and DFS between the SCRT + CCT and the CRT arms (OS: HR: 0.85, p = 0.07; DFS: HR: 0.88, p = 0.08). The compliance and toxicity were comparable between the SCRT and CRT groups. In the subgroup analysis, patients who underwent four or more cycles of CCT had better pCR and DFS events. Therefore, SCRT followed by consolidation chemotherapy might be an effective alternative treatment for LARC.

Preoperative short-course radiotherapy followed by consolidation chemotherapy for treatment with locally advanced rectal cancer: a meta-analysis

Background

The addition of consolidation chemotherapy to preoperative short-course radiotherapy during the prolonged interval between the completion of radiation and surgery in locally advanced rectal cancer (LARC) could enhance pathologic response and might act on potential micrometastasis. We performed this meta-analysis to evaluate whether short-course radiotherapy followed by consolidation chemotherapy (SCRT/CCT) could be a neoadjuvant treatment option compared with conventional long-course chemoradiotherapy (LCCRT).

Methods

We searched the PubMed, EMBASE, MEDLINE, and Cochrane Library databases. The primary endpoints were pathological outcomes, and the secondary endpoints included survival rate, sphincter preservation rate, R0 resection rate and toxicity. RevMan 5.3 was used to calculate pooled risk ratio (RRs) and 95% confidence intervals (CIs).

Results

A total of seven eligible studies and 1865 participants were included in this meta-analysis. Compared with the LCCRT, SCRT/CCT increased pathologic complete response (pCR) rate [RR = 1.74, 95% CI (1.41, 2.15), P < 0.01] and led to a lower proportion of patients with adjuvant pathologic tumor stage 3–4 (ypT3-4) disease [RR = 0.88, 95% CI (0.80, 0.97), P = 0.01] or lymph node positive (ypN +) disease [RR = 0.83, 95% CI (0.71, 0.98), P = 0.02]. In addition, the disease-free survival (DFS) was better in SCRT/CCT group [RR = 1.10, 95% CI (1.02, 1.18), P = 0.01], while overall survival rate and toxicity and surgical procedures were similar between two groups.

Conclusion

Based on better pathological outcomes and DFS in SCRT/CCT group, we recommended preoperative short-course radiotherapy followed by consolidation chemotherapy as the optional neoadjuvant treatment for LARC.