Short-Course Radiotherapy in Neoadjuvant Treatment for Rectal Cancer: A Systematic Review and Meta-analysis

X-ray-activated nanoscintillators integrated with tumor-associated neutrophils polarization for improved radiotherapy in metastatic colorectal cancer

Radiotherapy, employing high-energy rays to precisely target and eradicate tumor cells, plays a pivotal role in the treatment of various malignancies. Despite its therapeutic potential, the effectiveness of radiotherapy is hindered by the tumor's inherent low radiosensitivity and the immunosuppressive microenvironment. Here we present an innovative approach that integrates peroxynitrite (ONOO-)-mediated radiosensitization with the tumor-associated neutrophils (TANs) polarization for the reversal of immunosuppressive tumor microenvironment (TME), greatly amplifying the potency of radiotherapy. Our design employs X-ray-activated lanthanide-doped scintillators (LNS) in tandem with photosensitive NO precursor to achieve in-situ ONOO- generation. Concurrently, the co-loaded TGF-β inhibitor SB525334, released from the LNS-RS nanoplatform in response to the overexpressed GSH in tumor site, promotes the reprogramming of TANs from N2 phenotype toward N1 phenotype, effectively transforming the tumor-promoting microenvironment into a tumor-inhibiting state. This 'one-two punch' therapy efficiently trigger a robust anti-tumor immune response and exert potent therapeutic effects in orthotopic colorectal cancer and melanoma mouse model. Meanwhile, it also significantly prevents liver metastasis and recurrence in metastatic colorectal cancer. The development of X-ray-controlled platforms capable of activating multiple therapeutic modalities may accelerate the clinical application of radiotherapy-based collaborative therapy.

Efficacy of Neoadjuvant Hypofractionated Chemoradiotherapy in Elderly Patients with Locally Advanced Rectal Cancer: A Single-Center Retrospective Analysis

Background/Objectives: The application of long-course chemoradiotherapy (LCRT) in elderly patients with locally advanced rectal cancer (LARC) can be challenging due to increased risks of complications associated with comorbidities and reduced functional status. This study aimed to assess the efficacy of neoadjuvant hypofractionated chemoradiotherapy (HCRT) in elderly patients with mid-to-low LARC. Methods: We performed a retrospective review of patients diagnosed with LARC from January 2013 to December 2020 and included those aged 70 years or older. Patients were categorized into three groups based on their treatment strategies: neoadjuvant HCRT (33 or 35 Gy in 10 fractions), neoadjuvant LCRT, and upfront surgery. Comparative analyses were performed on clinicopathological characteristics, short-term outcomes, and long-term survival outcomes among these groups. Results: Among the 296 patients included, 30 (10.1%) received HCRT, 195 (65.9%) underwent standard LCRT, and 71 (24.0%) underwent upfront surgery. The baseline characteristics showed that the HCRT group had a higher American Society of Anesthesiologists (ASA) score (ASA score 3 or 4, HCRT 43.3% vs. LCRT 16.9% vs. upfront surgery 15.5%, p = 0.002). The HCRT group showed a significantly lower incidence of radiotherapy-related complications than the LCRT group (16.7% vs. 48.7%, p = 0.001). However, the rate of pathological complete response was significantly lower in the HCRT group (10.0% vs. 15.4%, p = 0.002). The 3-year relapse-free survival (83.0% vs. 77.2% vs. 83.2%; p = 0.411), 3-year local recurrence-free survival (93.1% vs. 93.2% vs. 93.5%; p = 0.464), and 5-year overall survival (65.1% vs. 67.0% vs. 67.7%; p = 0.682) were not significantly different between the three groups. Multivariate analysis also showed that the treatment strategy was not associated with survival outcomes. Conclusions: Neoadjuvant HCRT demonstrated reduced radiotherapy-related complications and acceptable long-term oncologic outcomes. Therefore, neoadjuvant HCRT may be considered as a viable alternative for elderly patients with LARC.

Comprehensive geriatric assessment guided radiotherapy in elderly patients with locally advanced rectal cancer-exploratory results on nonoperative cohort of a multicenter prospective study

Background

Chemoradiotherapy (CRT) is the main treatment for elderly patients with non-metastatic rectal cancer who are ineligible for or decline surgery, but the optimal modality remains unclear.

Objectives

This study was to validate the safety and efficacy of comprehensive geriatric assessment (CGA) guided radiotherapy in older patients.

Design

An exploratory analysis of a single-arm, multicenter, Phase II trial.

Methods

Patients aged over 70 and diagnosed with rectal cancer were enrolled and evaluated by CGA. CGA-guided radiotherapy was individually conducted in a multidisciplinary setting. Patients in fit, intermediate, and frail groups were scheduled to receive CRT, long-course radiotherapy, and short-course radiotherapy (SCRT) alone respectively. Patients who were unfit for or refused surgery were analyzed for acute toxicities and survival outcomes.

Results

In a total of 109 enrolled patients, 47 individuals who did not undergo surgery were included, with 26, 9, and 12 categorized into fit, intermediate, and frail groups. Only 11 (23.4%) grade 3 or above toxicities were observed overall. Within a median follow-up of 69.0 months, the 3-year overall survival (OS), progression-free survival (PFS), and cancer-specific survival (CSS) rates were 44.3% (95% CI: 32.1%-61.2%), 25.5% (95% CI: 15.7%-41.6%) and 61.0% (95% CI: 47.8%-77.6%) in total. The 5-year OS, PFS, and CSS reached 15.0% (95% CI: 7.4%-30.3%), 14.6% (95% CI: 7.3%-29.4%), and 36.2% (95% CI: 22.0%-59.4%), with no significant difference among the three subgroups. SCRT (p < 0.001) and dose boost (p = 0.045) contributed to lower tumor-related death rates in multiple competing risk regressions.

Conclusion

Radiotherapy guided by CGA was effective and well-tolerated in non-surgical elderly patients. SCRT alone seemed to achieve similar clinical outcomes as CRT in corresponding subgroups. However, given the limited size of this study, further investigation in a larger population is still needed for this strategy.

Pathologic response evaluation of localized or locally advanced esophageal carcinoma to induction chemotherapy followed by preoperative concurrent chemotherapy and hypofractionated radiotherapy: a clinical trial

Objective

Esophageal cancer is a therapeutic challenge in most healthcare systems. Most patients present with locally advanced disease at diagnosis. Concurrent chemoradiotherapy (CRT) is the standard treatment for locally advanced esophageal carcinoma. Since achieving a complete pathological response in postoperative specimens following neoadjuvant therapy is associated with improved patient survival, this study was designed to evaluate the pathologic response of localized or locally advanced esophageal carcinoma to induction chemotherapy followed by preoperative concurrent chemotherapy and hypofractionated radiotherapy (HFR).

Methods

This single-arm clinical trial (IRCT20210623051676N1) evaluated patients with squamous cell carcinoma or adenocarcinoma of the esophagus, stage cT2-T4a N0 M0 or cT1-T4a N+ M0. Patients received 3-5 cycles of weekly induction chemotherapy with the paclitaxel (50 mg/m2) and carboplatin (AUC=2) regimen, followed by weekly concurrent CRT with the same chemotherapy regimen. The radiation dose was 40 Gy, delivered over 16 fractions, 5 days per week (2.5 Gray/fraction). Patients underwent surgery 4-6 weeks after completion of CRT. The surgical specimens were evaluated for pathological response. A p-value of < 0.05 was considered significant in all analyses.

Results

Out of 54 patients enrolled in this study, 45 completed the neoadjuvant protocol. Of these 45 patients, 32 underwent surgery and were finally analyzed. The mean age of the patients was 59.9 ± 8.6 years (range, 37-75 years). The location of the tumor was in the mid-thoracic esophagus in most patients (21, 65.6%) and the most common histological type was SCC (29, 90.6%). The median number of induction and concurrent chemotherapy cycles was 5 (4.8 ± 1.3 course, range, 1-10) and 3 (2.6 ± 0.8 course, range, 0-4), respectively. Among 45 patients who completed the neoadjuvant protocol, the most common toxicities were grade 3 neutropenia (15.6%), acute renal failure (4.4%), and odynophagia (37.8%). Nearly two-thirds of the patients experienced complete or near-complete responses (71.9%, 23 patients). Partial response was reported in 6 patients (18.8%) and poor response in 3 patients (9.4%).

Conclusion

Preoperative induction chemotherapy followed by HFR with concurrent chemotherapy has low toxicity and side effects, good tolerance, and significant efficacy in the treatment of patients with esophageal cancer.

Clinical trial registration

https://irct.behdasht.gov.ir/trial/59930, identifier NCT05745545.

Guidance for Treating the Older Adults with Colorectal Cancer

OPINION STATEMENT

The need for evidence-based data in the rapidly growing group of older patients is vast and more elderly-specific studies are desperately needed, for which there is clear demand from both patients and providers. Notably, many of the studies discussed in this review included unplanned subset analyses based on age and/or were not originally stratified by age; therefore, these data, particularly overall survival data, need to be interpreted with some caution as they may not be statistically valid based on the initial trial design and statistical plan. As we await data from ongoing elderly-specific trials, our recommendation for managing older patients with CRC should include geriatric screening tools (e.g., CSGA, VES-13, G8, CARG, CRASH) to help guide treatment adjustments for improved tolerability without sacrificing efficacy. For patients with a positive screen for significant geriatric concerns, a full geriatric assessment is recommended to guide treatment approach and supportive care. Prior data support the use of all approved medications for CRC in older adults who are fit; however, treatment breaks and dose attenuation with potential escalation are reasonable options for these patients. Ultimately, management decisions in the care of older adults with mCRC must be made through shared decision-making with the patient with consideration for the patient's functional status, comorbidities, goals of care, social support, as well as potential toxicities and possible effect on QoL.

Combining chemotherapy and tislelizumab with preoperative split-course hypofraction radiotherapy for locally advanced rectal cancer: study protocol of a prospective, single-arm, phase II trial

INTRODUCTION

Short-course radiotherapy (SCRT) with systemic therapy has the potential to further improve the long-term efficacy in patients with locally advanced rectal cancer (LARC). To maximise the benefits of neoadjuvant therapy for improved prognosis, it is important to determine the optimal mix of chemotherapy, immunotherapy and SCRT.

METHODS AND ANALYSIS

Fifty treatment-naïve patients with operable LARC (T3-4 and/or N+) will be recruited. Patients will be synchronously treated with capecitabine plus oxaliplatin (CAPOX) chemotherapy, tislelizumab and preoperative split-course hypofraction radiotherapy (SCHR) (5×7 Gy) before surgery. Chemotherapy for CAPOX starts on day 1 of every 21-day cycle: on day 1, oxaliplatin 130 mg/m² will be injected intravenously. On days 1-14, capecitabine 1000 mg/m² was ingested two times a day. Simultaneously, tocilizumab 200 mg will be given intravenously on the first day of every 21-day cycle. A single 7 Gy SCHR treatment (day 7 of each 21-day cycle) will be delivered five times during the seventh day of treatment. The primary endpoint will be pathological complete response. The secondary outcomes will be the 3-year disease-free survival, local recurrence rate, overall survival, sphincter-sparing surgery rate, R0 resection rate, predictive biomarkers and quality of life.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of Xiehe Affiliated Hospital of Fujian Medical University (XAHFMU) (No. 2021YF025-01). Results from our study will be disseminated in international peer-reviewed journals. All study procedures were developed in order to assure data protection and confidentiality.

TRIAL REGISTRATION NUMBER

NCT05176964.

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.

Non-Operative Management of Patients with Rectal Cancer: Lessons Learnt from the OPRA Trial

Over the past decade, the management of locally advanced rectal cancer (LARC) has progressively become more complex. The introduction of total neoadjuvant treatment (TNT) has increased the rates of both clinical and pathological complete response, resulting in excellent long-term oncological outcomes. As a result, non-operative management (NOM) of LARC patients with a clinical complete response (cCR) after neoadjuvant therapy has gained acceptance as a potential treatment option in selected cases. NOM is based on replacement of surgical resection with safe and active surveillance. However, the identification of appropriate candidates for a NOM strategy without compromising oncologic safety is currently challenging due to the lack of an objective standardization. NOM should be part of the treatment plan discussion with LARC patients, considering the increasing rates of cCR, patient preference, quality of life, expectations, and the potential avoidance of surgical morbidity. The recently published OPRA trial showed that organ preservation is achievable in half of rectal cancer patients treated with TNT, and that chemoradiotherapy followed by consolidation chemotherapy may an appropriate strategy to maximize cCR rates. Ongoing trials are investigating optimal algorithms of TNT delivery to further expand the pool of patients who may benefit from NOM of LARC.

Toxicities and outcomes of neoadjuvant treatment in elderly patients with locally advanced rectal cancer: a scoping review protocol

INTRODUCTION

Colorectal cancer remains the second leading cause of cancer-related death in 60-79 years old and the third leading cause of death in patients aged 80 and above. Rectal cancer accounts for approximately a third of colorectal cancer diagnoses. The current standard of care for managing locally advanced rectal cancer involves a multimodal combined approach with neoadjuvant treatment, surgery with total mesorectal excision and adjuvant chemotherapy. Neoadjuvant treatment can be in the form of short-course radiotherapy, long-course concurrent radiotherapy with chemotherapy or total neoadjuvant chemotherapy with concurrent chemoradiotherapy followed by chemotherapy. This scoping aims to assess the toxicity and outcome of the different neoadjuvant treatment modalities in elderly patients.

METHODS AND ANALYSIS

We will use Arksey and O'Malley's five scoping review methodology framework stages. Searches will be conducted in Ovid Medline, Embase, Cochrane database and CINAHL. In addition, the researcher will hand search for all registered trials, using a combination of terms such as "locally advanced rectal cancer", "neoadjuvant treatment", and "elderly patients." Two independent reviewers will screen titles and abstracts and then full text based on predefined inclusion and exclusion criteria. Publications will be extracted using a customised data extraction tool to include study characteristics, research topics, exposures and outcomes.

ETHICS AND DISSEMINATION

Ethics approval is not required as the data will be collected from the existing literature. The findings of this study will help with future clinical research on the topic. We will publish the findings of this review in a peer-reviewed journal and present them at academic conferences targeting geriatric oncology service providers.

Preoperative radiotherapy 5 × 5 Gy and short versus long interval between surgery for resectable rectal cancer: 10-Year follow-up of the randomised controlled trial

BACKGROUND

Studies on short-course preoperative radiotherapy in combination with total mesorectal excision for rectal cancer reported improved local control without clear survival benefits. The optimal fractionation and interval between radiotherapy and surgery are still under debate. We, therefore, aimed to report 10-year results of a randomized clinical trial (RCT, NCT01444495) comparing different time intervals between irradiation and surgery for rectal cancer.

MATERIAL AND METHODS

Data from the RCT conducted at a single academic centre were reviewed based on regular control visits with the median follow-up of 12 years. Patients with rectal cancer were randomly assigned to short-course preoperative radiotherapy (5 × 5 Gy) followed by surgery 7-10 days (short interval) or 4-5 weeks (long interval) after the end of irradiation. The primary endpoint was the local recurrence rate at 5 years. The secondary endpoints included overall survival, disease-free survival, systemic recurrence rate, and downstaging.

RESULTS

A total of 154 patients were randomly assigned to short (n = 77) or long interval (n = 77) surgery. The cumulative incidence of local recurrence at 10 years was 1.3% and 11.7% in the short and long-interval groups, respectively (p = 0.031). Accordingly, the incidence of systemic relapse was 14.3% versus 9.1% (p = 0.0319). There were no differences in the overall 10-year survival between patients subject to short and long-interval surgery (58% vs 61%, p = 0.754). However, patients with downstaging after radiotherapy had significantly better 10-year survival rates than non-responders.

CONCLUSIONS

Short-course preoperative radiotherapy with delayed surgery demonstrated an increased risk of local relapse over a 10-year follow-up.

Neoadjuvant short-course radiotherapy with consolidation chemotherapy for locally advanced rectal cancer: a systematic review and meta-analysis

BACKGROUND

Short-course radiotherapy with consolidation chemotherapy (SCRT-CCT) has emerged as a promising alternative to the long course chemoradiotherapy (LCRT) regimen in locally advanced rectal cancer management. The systematic review and meta-analysis is aimed at summarizing current evidence on SCRT-CCT and comparing it to LCRT.

MATERIAL AND METHODS

Electronic databases of MEDLINE, Web of Science, and Cochrane library were searched using a predefined search strategy returning 3314 articles. This review included 11 studies (6 randomized trials and 5 non-randomized studies) on SCRT-CCT regimen based on seven different cohorts. Weighted arithmetic means and forest plots were generated to determine summary estimates.

RESULTS

The probability of achieving pathological complete response (pCR) was higher with SCRT-CCT compared to LCRT (risk ratio [RR] = 1.75, 95% confidence interval [CI]: 1.41-2.19). No statistically significant difference in 3-year overall survival (OS) was observed between the two groups (RR= 1.06, 95% CI: 0.98-1.14). The weighted arithmetic mean of 3-year OS and pCR was 83.6% versus 80.9%, and 24.5% versus 13.6% for SCRT-CCT and LCRT, respectively. R0 resection and T-downstaging rates ranged from 69.2-100% to 47-75% for SCRT-CCT, and 71-92.3% and 41-75% for LCRT, respectively. The regimens had similar compliance, postoperative, and late toxicity, however, acute toxicity rates varied primarily due to differences in treatment protocols.

CONCLUSIONS

This review highlights the ability of SCRT-CCT to produce improved tumor response with comparable OS, R0 resection, and T-downstaging at the cost of increased acute toxicity. However, heterogeneity in treatment protocols across studies makes it difficult to provide definitive conclusions regarding the regimen. Several ongoing trials are expected to provide further evidence confirming the findings of RAPIDO trial and detail appropriate SCRT-CCT protocols to improve oncological outcomes, minimize toxicity, and determine its effectiveness as the standard-of-care for locally advanced rectal cancer patients.

Total Neoadjuvant Therapy (TNT) versus Standard Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Total neoadjuvant therapy (TNT) is a novel approach for locally advanced rectal cancer (LARC), which attempts to deliver both systemic chemotherapy and neoadjuvant chemoradiotherapy prior to surgery. However, its efficacy and safety remain controversial in randomized controlled trials (RCTs). We conducted this meta-analysis to assess such concerns.

MATERIALS AND METHODS

Head-to-head phase II/III RCTs were searched in Embase, PubMed, Web of Science, and the Cochrane Library, as well as other sources. The primary endpoint was pathologic complete response (pCR). Secondary endpoints were disease-free survival (DFS), overall survival (OS), local recurrence-free survival, distant metastasis-free survival, and the R0 resection rate.

RESULTS

Eight phase II/III RCTs involving 2,196 patients with LARC were assessed. The primary analysis demonstrated a statistically significant improvement in the pCR rate for TNT treatment (odds ratio, 1.77; 95% confidence interval [CI], 1.28-2.45; p = .0005). TNT treatment also showed improvements in DFS and OS outcomes compared with standard chemoradiotherapy (hazard ratio [HR], 0.83; 95% CI, 0.72-0.96; p = .03 and HR, 0.88; 95% CI, 0.74-1.05; p = .15). In addition, TNT treatment showed significant efficacy in reducing the risk of distant metastasis (HR, 0.81; 95% CI, 0.68-0.95; p = .012).

CONCLUSION

The overall pCR rate may be improved with TNT compared with standard treatment. The TNT strategy may also improve DFS and OS and reduce the risk of distant metastasis.

IMPLICATIONS FOR PRACTICE

Locally advanced rectal cancer (LARC) is a relatively common disease, with a poor prognosis because of its high metastatic potential. The role of total neoadjuvant therapy (TNT) has always been controversial. This meta-analysis found that TNT in LARC is associated with a significant improvement in overall pathologic complete response rate, disease-free survival, overall survival, and distant metastasis-free survival compared with standard treatment. TNT is a promising strategy for LARC, especially for patients who have little desire for surgery.

Multidisciplinary management of elderly patients with rectal cancer: recommendations from the SICG (Italian Society of Geriatric Surgery), SIFIPAC (Italian Society of Surgical Pathophysiology), SICE (Italian Society of Endoscopic Surgery and new technologies), and the WSES (World Society of Emergency Surgery) International Consensus Project

BACKGROUND AND AIMS

Although rectal cancer is predominantly a disease of older patients, current guidelines do not incorporate optimal treatment recommendations for the elderly and address only partially the associated specific challenges encountered in this population. This results in a wide variation and disparity in delivering a standard of care to this subset of patients. As the burden of rectal cancer in the elderly population continues to increase, it is crucial to assess whether current recommendations on treatment strategies for the general population can be adopted for the older adults, with the same beneficial oncological and functional outcomes. This multidisciplinary experts' consensus aims to refine current rectal cancer-specific guidelines for the elderly population in order to help to maximize rectal cancer therapeutic strategies while minimizing adverse impacts on functional outcomes and quality of life for these patients.

METHODS

The discussion among the steering group of clinical experts and methodologists from the societies' expert panel involved clinicians practicing in general surgery, colorectal surgery, surgical oncology, geriatric oncology, geriatrics, gastroenterologists, radiologists, oncologists, radiation oncologists, and endoscopists. Research topics and questions were formulated, revised, and unanimously approved by all experts in two subsequent modified Delphi rounds in December 2020-January 2021. The steering committee was divided into nine teams following the main research field of members. Each conducted their literature search and drafted statements and recommendations on their research question. Literature search has been updated up to 2020 and statements and recommendations have been developed according to the GRADE methodology. A modified Delphi methodology was implemented to reach agreement among the experts on all statements and recommendations.

CONCLUSIONS

The 2021 SICG-SIFIPAC-SICE-WSES consensus for the multidisciplinary management of elderly patients with rectal cancer aims to provide updated evidence-based statements and recommendations on each of the following topics: epidemiology, pre-intervention strategies, diagnosis and staging, neoadjuvant chemoradiation, surgery, watch and wait strategy, adjuvant chemotherapy, synchronous liver metastases, and emergency presentation of rectal cancer.

Locally advanced rectal cancer: The past, present, and future

From a series of clinical trials in the last several decades, current treatment paradigms for locally advanced rectal cancer include: (1) preoperative long-course radiotherapy (RT) combined with radiosensitizing chemotherapy; (2) preoperative short-course RT alone followed by adjuvant postoperative chemotherapy; and (3) total neoadjuvant therapy with induction chemotherapy followed by chemoradiotherapy. Other strategies under active investigation in both institutional and cooperative trials include neoadjuvant chemotherapy alone without RT in select patients, total neoadjuvant therapy, watchful waiting after a clinical complete response as an alternative to surgical resection, and the use of different chemotherapeutic and targeted agents. The focus of this review is on established and novel therapeutic strategies for locally advanced rectal cancer.

Pathologic Response and Postoperative Complications After Short-course Radiation Therapy and Chemotherapy for Patients With Rectal Adenocarcinoma

BACKGROUND

The role of neoadjuvant short-course radiation therapy (SCRT) in treating rectal adenocarcinoma is a topic of ongoing debate. Growing interest in total neoadjuvant therapy has spurred discussion on the optimal sequence of preoperative SCRT and chemotherapy.

PATIENTS AND METHODS

All patients receiving SCRT (5 Gy × 5 fractions) were identified. Details about preoperative treatments, radiation toxicities, and postoperative complications were collected. Patients were divided into 2 groups: those who underwent surgery within 14 days of completing SCRT and those with a longer delay. Outcomes compared included extent of pathologic response, margin-negative resection rate, acute radiation toxicities, and postoperative complications.

RESULTS

Fifty-seven patients with locally advanced or metastatic rectal cancer received SCRT between 2008 and 2018. Thirty-nine of 57 patients underwent definitive pelvic surgery with total mesorectal excision. There were no significant differences in tumor downstaging, radial margin status, or percent tumor viability between patients with immediate surgery versus delayed surgery. The delay group had higher rates of nodal downstaging (64.7% vs. 18.2%; P = .003). There were no differences in total or grade 3+ gastrointestinal radiation toxicity, postoperative complications, reoperation, readmission, and mortality between the 2 groups.

CONCLUSIONS

Though not yet common in the United States, SCRT has compared favorably with long course chemoradiation in multiple trials. Moreover, it is associated with greater efficiency and less disruption to chemotherapy. Our data show similar response and toxicity outcomes between the immediate and delay groups, suggesting SCRT is well-tolerated regardless of treatment sequence. Recently completed prospective trials may reveal the optimal preoperative treatment sequence.

Predictors for complete pathological response for stage II and III rectal cancer following neoadjuvant therapy - A systematic review and meta-analysis

BACKGROUND

There has been an increasing interest in the complete pathological response (pCR) in rectal cancers following neoadjuvant therapy. The aim of this study was to identify predictive factors of pCR in locally advanced rectal cancer following neoadjuvant therapy.

METHODS

The studies identified were appraised with standard selection criteria. The selection criteria included studies on patients with stage II or III rectal cancer who underwent neoadjuvant therapy.

RESULTS

Patients with pCR are more likely to be older (p = 0.0002), have cancers closer distance to the anal verge (p < 0.00001), smaller tumors (P < 0.0001), no clinical lymph nodes involvement (p=<0.00001) and waited more than eight weeks until definitive surgery (p = 0.002). There was no difference in gender (p = 0.15) and tumor differentiation (p = 0.21).

CONCLUSIONS

The 'Watch and Wait' approach may be appropriate for selected patients. Patients with lower rectal cancers, smaller tumors, and negative clinical lymph node involvement may be more likely to achieve pCR following neoadjuvant therapy.

Preoperative short-course radiotherapy (5 × 5 Gy) with delayed surgery versus preoperative long-course radiotherapy for locally resectable rectal cancer: a meta-analysis

PURPOSE

Preoperative short-course radiotherapy (PSRT) and preoperative long-course radiotherapy (PLRT) are standard treatment regimens for locally advanced rectal cancer. However, whether the efficacy and safety of PSRT with delayed surgery (more than 4 weeks) are superior to those of PLRT remains unresolved and was explored in this meta-analysis.

METHODS

Studies published in PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov databases were systematically searched. RevMan 5.3 was used to calculate pooled hazard ratios (HR) and relative risk (RR).

RESULTS

Seven studies including 4973 patients were identified in the meta-analysis. Pooled statistics showed that there was no statistically significant difference in overall survival (HR = 1.30, 95% CI 0.58-2.89, P = 0.52) or disease-free survival (HR = 1.10, 95% CI 0.73-1.66, P = 0.64) between the preoperative short-course and long-course radiotherapy groups. Moreover, pathological complete remission, early postoperative complications, treatment-related grade 3/4 toxicity, local recurrence, and distant metastasis were similar between the two groups. Interestingly, a subgroup analysis revealed that preoperative short-course radiotherapy without adjuvant chemotherapy not only resulted in lower treatment-related grade 3/4 toxicity than the long-course radiotherapy group (RR = 0.19, 95% CI 0.08-0.48, P < 0.01) but also resulted in significantly lower overall survival and pathological complete remission (P = 0.02, P < 0.01, respectively). Disappointingly, pooled statistics observed few advantages over long-course radiotherapy in short-course radiotherapy with the adjuvant chemotherapy subgroup.

CONCLUSIONS

PSRT with delayed surgery was as effective as PLRT for the management of locally resectable rectal cancer. However, not adding additional chemotherapy to PSRT not only significantly decreased grade 3/4 toxicity but also decreased pathological complete remission and overall survival.

TRIAL REGISTRATION

The protocol for this meta-analysis was prospectively registered with PROSPERO (CRD42019133641).

Comparison of efficacy, safety, and costs between neoadjuvant hypofractionated radiotherapy and conventionally fractionated radiotherapy for esophageal carcinoma

Background

We compared the efficacy, safety, and costs of hypofractionated radiotherapy (HFRT) and conventional fractionated radiotherapy (CFRT) for the neoadjuvant treatment of esophageal cancer.

Materials and Methods

Overall, 110 patients with esophageal cancer treated with neoadjuvant chemoradiotherapy from October 2002 to July 2017 were retrospectively included and divided into a HFRT group (42 patients received 30 Gray [Gy]/10 fractions for 2 weeks) and a CFRT group [68 patients received 40 Gy/20 fractions for 4 weeks]. Concurrent chemotherapy comprised cisplatin combined with either 5‐FU or taxane. Surgery was performed 3‐8 weeks after radiotherapy. We compared the outcomes, adverse events, and costs between the two groups.

Results

Pathological downstaging was achieved in 78.6% of the HFRT group and 83.8% of the CFRT group (P = 0.612). Compared with the CFRT group, the HFRT group had similar pathological complete response (pCR) (33.3% vs 35.3%; P = 0.834), median overall survival (OS) (40.8 months vs 44.9 months; P = 0.772) and progression free survival (32.7 months vs 35.4 months; P = 0.785). The perioperative complication rates were also similar between the groups, but the treatment time and costs were significantly reduced in the HFRT group (P < 0.05). Finally, multivariate analysis identified cN0 stage, pathological downstaging and pCR as independent predictors of better OS.

Conclusion

Preoperative HFRT is effective and safe for esophageal cancer. Moreover, it is similar to CFRT in terms of overall survival and toxicity and is cost effective and less time consuming.