Preoperative chemoradiotherapy versus preoperative radiotherapy in rectal cancer patients: assessment of acute toxicity and treatment compliance

Evaluating the Effectiveness of Proton Beam Therapy Compared to Conventional Radiotherapy in Non-Metastatic Rectal Cancer: A Systematic Review of Clinical Outcomes

Background and Objectives: Conventional radiotherapies used in the current management of rectal cancer commonly cause iatrogenic radiotoxicity. Proton beam therapy has emerged as an alternative to conventional radiotherapy with the aim of improving tumour control and reducing off-set radiation exposure to surrounding tissue. However, the real-world treatment and oncological outcomes associated with the use of proton beam therapy in rectal cancer remain poorly characterised. This systematic review seeks to evaluate the radiation dosages and safety of proton beam therapy compared to conventional radiotherapy in patients with non-metastatic rectal cancer. Materials and Methods: A computer-assisted search was performed on the Medline, Embase and Cochrane Central databases. Studies that evaluated the adverse effects and oncological outcomes of proton beam therapy and conventional radiotherapy in adult patients with non-metastatic rectal cancer were included. Results: Eight studies were included in this review. There was insufficient evidence to determine the adverse treatment outcomes of proton beam therapy versus conventional radiotherapy. No current studies assessed radiotoxicities nor oncological outcomes. Pooled dosimetric comparisons between proton beam therapy and various conventional radiotherapies were associated with reduced radiation exposure to the pelvis, bowel and bladder. Conclusions: This systematic review demonstrates a significant paucity of evidence in the current literature surrounding adverse effects and oncological outcomes related to proton beam therapy compared to conventional radiotherapy for non-metastatic rectal cancer. Pooled analyses of dosimetric studies highlight greater predicted radiation-sparing effects with proton beam therapy in this setting. This evidence, however, is based on evidence at a moderate risk of bias and clinical heterogeneity. Overall, more robust, prospective clinical trials are required.

Changes in serum uric acid, serum uric acid/serum creatinine ratio, and gamma-glutamyltransferase might predict the efficacy of neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

PURPOSE

The purpose of this study was to investigate the predictive value of changes in serum uric acid (SUA), the ratio of serum uric acid to serum creatinine (SUA/SCr), and serum gamma-glutamyltransferase (GGT) from before to after therapy in patients with locally advanced rectal cancer (LARC).

METHODS

Data from 114 LARC patients from January 2016 to December 2021 were included in this retrospective study. All patients received neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME). The change in SUA was calculated as a ratio: (SUA level after nCRT-SUA level before nCRT)/SUA level before nCRT. The change ratios of SUA/SCr and GGT were calculated in the same way. The efficacy of nCRT was evaluated by magnetic resonance (MR) and postoperative pathological response. A nonlinear model was used to evaluate whether the change ratios of SUA, SUA/SCr, and GGT were associated with the efficacy of nCRT. The predictive power of the change ratios of SUA, SUA/SCr, and GGT was assessed by receiver operating characteristic (ROC) curves. Univariate and multivariate Cox regression analyses were employed to measure the associations between disease-free survival (DFS) and other predictive indicators. The Kaplan-Meier method was used to further compare DFS between groups.

RESULTS

The nonlinear model indicated that the change ratios of SUA, SUA/SCr, and GGT were associated with the efficacy of nCRT. The change ratios of SUA, SUA/SCr, and GGT were used to predict the area under the ROC curve of efficacy for nCRT (0.95, 0.91-0.99), which was better than the prediction by the change ratio of SUA (0.94, 0.89-0.99), SUA/SCr (0.90, 0.84-0.96), or GGT alone (0.86, 0.79-0.93; p < 0.05). The optimal cut-off values of SUA, SUA/SCr, and GGT change were 0.02, 0.01, and 0.04, respectively. The Kaplan-Meier method indicated that patients with SUA, SUA/SCr, or GGT changes greater than the cut-off values had shorter DFS (p < 0.05).

CONCLUSION

Change ratios of SUA, SUA/SCr, or GGT greater than the cut-off values implied a risk of poor pathological response after nCRT and shorter DFS in LARC patients.

Excluding external iliac node irradiation during neoadjuvant radiotherapy decreases lower intestinal toxicity without compromising efficacy in T4b rectal cancer patients with tumours involving the anterior structures

PURPOSE

To explore the impact of excluding the external iliac node (EIN) from the clinical target volume (CTV) during preoperative radiotherapy in T4b rectal cancer with anterior structure invasion.

METHODS

We retrospectively identified 132 patients with T4b rectal cancer involving the anterior structures who received radiotherapy followed by surgery between May 2010 and June 2019. Twenty-nine patients received EIN irradiation (EIN group), and 103 did not (NEIN group). Failure patterns, survival and toxicities were compared between the two groups.

RESULTS

The most common failure was distant metastasis (23.5%). 11 (8.3%) patients developed locoregional recurrence, 10 (9.7%) patients were in the NEIN group, and 1 (3.4%) was in the EIN group (P = 0.34). The EIN region failure was rare (1/132, 0.8%). The locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), overall survival (OS) and progression-free survival (PFS) rates were 96.3% vs. 90.5%, 82.1% vs.73.7%, 75.9% vs. 78.0% and 72.4% vs. 68.3% (all P > 0.05) for the EIN group and NEIN group, respectively. The incidence of grade 3-4 acute toxicity in the lower intestine was significantly higher in the EIN group than in the NEIN group (13.8% vs. 1.9%, P = 0.02). The Dmax, V35 and V45 of the small bowel was decreased in the NEIN group compared to the EIN group.

CONCLUSIONS

Exclusion of the EIN from the CTV in T4b rectal cancer with anterior structure invasion could reduce lower intestinal toxicity without compromising oncological outcomes. These results need further evaluation in future studies.

The Impact on Survival of Neoadjuvant Treatment Interruptions in Locally Advanced Rectal Cancer Patients

The standard oncologic treatment of locally advanced rectal cancer is long-course radio-chemotherapy followed by surgery and adjuvant chemotherapy. This can result in a lengthy total treatment duration, sometimes up to one year from the diagnosis. Interruptions to neoadjuvant treatment can occur for a variety of reasons, forced or unforced. The main purpose of this study is to analyze the survival data of locally advanced rectal cancer patients who received neoadjuvant treatment and to find a cut-off point showing exactly how many days of interruption of neoadjuvant treatment the risk of death or disease relapse increases. We conducted a retrospective study on 299 patients with locally advanced rectal cancer using survival analysis (Kaplan-Meier curve and Cox regression) to determine survival probabilities for overall survival, local control, and disease-free survival. Patients with 0 to 3 days of neoadjuvant therapy interruption had a higher overall survival probability compared to patients with 4 or more days (90.2% compared to 57.9%, p-value < 0.001), hazard ratio 5.89 (p < 0.001). Local control and disease-free survival had a higher probability in patients with 0-2 days of interruption compared to people with 3 or more days (94% vs. 75.4%, and 82.2% vs. 50.5%, respectively, both p-values < 0.001). Patients with tumoral or nodal downstaging experienced fewer days of interruption than patients with no downstage. These findings reinforce the need for radiation oncologists to be well-organized when starting neoadjuvant treatment for rectal cancer, in order to anticipate and prevent potential treatment interruptions and achieve the best therapeutic results.

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.

The Crying Need for a Better Response Assessment in Rectal Cancer

OPINION STATEMENT

Since total neoadjuvant treatment achieves almost 30% pathologic complete response, organ preservation has been increasingly debated for good responders after neoadjuvant treatment for patients diagnosed with rectal cancer. Two organ preservation strategies are available: a watch and wait strategy and a local excision strategy including patients with a near clinical complete response. A major issue is the selection of patients according to the initial tumor staging or the response assessment. Despite modern imaging improvement, identifying complete response remains challenging. A better selection could be possible by radiomics analyses, exploiting numerous image features to feed data characterization algorithms. The subsequent step is to include baseline and/or pre-therapeutic MRI, PET-CT, and CT radiomics added to the patients' clinicopathological data, inside machine learning (ML) prediction models, with predictive or prognostic purposes. These models could be further improved by the addition of new biomarkers such as circulating tumor biomarkers, molecular profiling, or pathological immune biomarkers.

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 outcome after total neoadjuvant treatment (CAO/ARO/AIO-12) versus intensified neoadjuvant and adjuvant treatment (CAO/ARO/AIO-04) a comparison between two multicenter randomized phase II/III trials

BACKGROUND

Total neoadjuvant therapy (TNT) can enhance local tumor regression, but its survival benefits compared to intensified chemoradiotherapy (CRT) followed by adjuvant chemotherapy (CT) remain unclear.

METHODS

This is a secondary comparison between 607 patients treated with intensified 5-FU/Oxaliplatin neoadjuvant CRT and adjuvant CT within the experimental arm of the CAO/ARO/AIO-04 phase III trial, and 306 patients treated with TNT within the CAO/ARO/AIO-12 phase II trial. Comparison between clinical-pathological characteristics, surgical quality, and post-surgical complications were analyzed using the Pearson's Chi-squared or Mann-Whitney U test. Oncological outcome was examined with log-rank, Gray's test, and multivariate cox regression. In addition, further subgroup analyses and propensity score matching were performed to optimize the balance of baseline covariates.

FINDINGS

Patients treated with CRT followed by consolidation CT had a significantly higher rate of pathological complete remission (pCR) compared to patients treated within the experimental arm of the CAO/ARO/AIO-04 trial (25.3 % vs 17.3 %, P = 0.04). Post-surgical complications were less common in the CAO/ARO/AIO-12 trial. After a median follow-up of 46 months, clinical outcome did not differ significantly in the overall cohort, in any subgroup or after propensity score matching. In multivariate analysis, disease-free survival (DFS) was similar between the experimental arm of the CAO/ARO/AIO-04 trial and treatments arms of the CAO/ARO/AIO-12 trial (vs arm A: HR 0.92 [95 % CI 0.62-1.37], P = 0.69; vs arm B: HR 1.06 [95 % CI 0.72-1.58], P = 0.76).

INTERPRETATION

Notwithstanding the limitations of intertrial comparison, TNT did not improve long term oncological outcome in our study compared to the intensified neoadjuvant CRT and adjuvant CT treatment in the CAO/ARO/AIO-04 trial. Improved response rates after TNT offers an attractive option to explore organ preservation in selective patients with locally advanced rectal cancer.

Efficacy and safety of different radiotherapy doses in neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer: A retrospective study

Background

This study aims to compare the efficacy and safety of neoadjuvant chemoradiotherapy (nCRT) with different radiotherapy doses (45Gy and 50.4Gy) in patients with locally advanced rectal cancer (LARC).

Methods

Herein, 120 patients with LARC were retrospectively enrolled between January 2016 and June 2021. All patients underwent two courses of induction chemotherapy (XELOX), chemoradiotherapy, and total mesorectum excision (TME). A total of 72 patients received a radiotherapy dose of 50.4 Gy, while 48 patients received a dose of 45 Gy. Surgery was then performed within 5-12 weeks following nCRT.

Results

There was no statistically significant difference between the baseline characteristics of the two groups. The rate of good pathological response in the 50.4Gy group was 59.72% (43/72), while in the 45Gy group achieved 64.58% (31/48) (P>0.05). The disease control rate (DCR) in the 50.4Gy group was 88.89% (64/72), compared to 89.58% (43/48) in the 45Gy group (P>0.05). The incidence of adverse reactions for radioactive proctitis, myelosuppression, and intestinal obstruction or perforation differed significantly between the two groups (P<0.05). The anal retention rate in the 50.4Gy group was significantly higher in contrast to the 45Gy group (P<0.05).

Conclusions

Patients receiving a radiotherapy dose of 50.4Gy have a better anal retention rate but also a higher incidence of adverse events such as radioactive proctitis, myelosuppression, and intestinal obstruction or perforation, and a comparable prognosis to patients treated with a radiotherapy dose of 45Gy.

Preoperative short-course radiation therapy with PROtons compared to photons in high-risk RECTal cancer (PRORECT): Initial dosimetric experience

Background and purpose

Neoadjuvant short-course radiotherapy (SCRT) followed by full-dose systemic chemotherapy is an established treatment modality in locally advanced rectal cancer (LARC). Until recently, SCRT has been exclusively delivered with photons. Proton beam therapy (PBT) may minimize acute toxicity, which in turn likely impacts favorably on the tolerability to subsequent chemotherapy. The aim of this study is a dosimetric comparison between SCRT with photons and protons in the randomized phase II trial PRORECT (NCT04525989).

Materials and methods

From June 2021 to June 2022, twenty consecutive patients with LARC have been treated according to study protocol. For each patient, both a VMAT and a PBT treatment plans have been generated and compared pairwise.

Results

Dose-volume histogram (DVH) analysis revealed that SCRT with protons significantly reduced radiation dose to pelvic organs at risk including bladder, bones, and bowel in comparison to SCRT with photons. Photon and proton treatment plans had equivalent conformity and homogeneity indexes.

Conclusion

Preoperative SCRT with protons offers a significant reduction of radiation dose to normal tissues compared with current photon-based radiotherapy technique. Demonstrated dosimetric advantages may translate into measurable clinical benefits in patients with LARC. Clinical implications of the dosimetric superiority of SCRT with protons will be presented in the coming reports from the PRORECT trial.

Development and Validation of a Predictive Model for Toxicity of Neoadjuvant Chemoradiotherapy in Rectal Cancer in the CAO/ARO/AIO-04 Phase III Trial

Background: There is a lack of predictive models to identify patients at risk of high neoadjuvant chemoradiotherapy (CRT)-related acute toxicity in rectal cancer. Patient and Methods: The CAO/ARO/AIO-04 trial was divided into a development (n = 831) and a validation (n = 405) cohort. Using a best subset selection approach, predictive models for grade 3−4 acute toxicity were calculated including clinicopathologic characteristics, pretreatment blood parameters, and baseline results of quality-of-life questionnaires and evaluated using the area under the ROC curve. The final model was internally and externally validated. Results: In the development cohort, 155 patients developed grade 3−4 toxicities due to CRT. In the final evaluation, 15 parameters were included in the logistic regression models using best-subset selection. BMI, gender, and emotional functioning remained significant for predicting toxicity, with a discrimination ability adjusted for overfitting of AUC 0.687. The odds of experiencing high-grade toxicity were 3.8 times higher in the intermediate and 6.4 times higher in the high-risk group (p < 0.001). Rates of toxicity (p = 0.001) and low treatment adherence (p = 0.007) remained significantly different in the validation cohort, whereas discrimination ability was not significantly worse (DeLong test 0.09). Conclusion: We developed and validated a predictive model for toxicity using gender, BMI, and emotional functioning. Such a model could help identify patients at risk for treatment-related high-grade toxicity to assist in treatment guidance and patient participation in shared decision making.

[Place of radiotherapy in the treatment of rectal cancer in the elderly]

Rectal cancer is a common disease of the elderly. Current treatment recommendations are established for young subjects in good general health condition, without taking into account the frailty, comorbidities and polymedications inherent in patients over 75 years old. For locally advanced lower and middle rectal cancers (T3, T4 or N+), these are based on variations of regimens including neoadjuvant chemoradiotherapy, surgery of the rectum with total removal of the mesorectum, and a possibility of adjuvant chemotherapy. This restrictive treatment presents a problem of compliance and is not without adverse effects. Treatment by short exclusive radiotherapy or chemoradiotherapy with close monitoring according to the Watch and Wait strategy can be proposed to fragile patients not eligible for surgery, even if there is a non-negligible risk of recurrence.

Thermosensitive and tum or microenvironment activated nanotheranostics for the chemodynamic/photothermal therapy of colorectal tumor

This research proposes the one-pot preparation of polydopamine (PDA) decorated mesoporoussilica nanoparticle (PMSN) for the thermal and tumor micro-environment (TME) responsive colorectal tumor therapy. The pores of PMSN were used for the Fe³⁺ loading. Lauric acid (LA), a phase-change ligand, was selected as a "doorkeeper" to coat the surface of Fe³⁺-loaded PMSN and prevent the undesired leakage of Fe³⁺. Bovine serum albumin (BSA) was selected as a stabilizer to endow the PMSN-Fe-LA-BSA nanopartilces (PMFLB) with colloidal stability. Under the near infrared laser, the light-sensitive PDA produced significant heat to kill the colorectal cancer cells via hyperthermia. Moreover, the heat induced the phase-change of LA and triggered the release of Fe³⁺, which further reacted with the endogenous H₂S in the colorectal TME. After that, the Fe³⁺ was transformed into Fe²⁺, which triggered the Fenton reaction with the H₂O₂ in the TME and effectively generated hydroxyl radical (·OH). Finally, the Fe²⁺ was transformed into Fe³⁺, which repeatedly reacted with the H₂S and produced more ·OH to enhance the chemodynamic therapy of colorectal tumor. Such a thermosensitive PMFLB which operates in synergy with the colorectal TME opens an alternative avenue for the rational design of multifunctional nano-therapeutic agents.

Neoadjuvant therapy versus direct to surgery for T4 colon cancer: meta-analysis

BACKGROUND

Despite persistently poor oncological outcomes, approaches to the management of T4 colonic cancer remain variable, with the role of neoadjuvant therapy unclear. The aim of this review was to compare oncological outcomes between direct-to-surgery and neoadjuvant therapy approaches to T4 colon cancer.

METHODS

A librarian-led systematic search of MEDLINE, Embase, the Cochrane Library, Web of Science, and CINAHL up to 11 February 2020 was performed. Inclusion criteria were primary research articles comparing oncological outcomes between neoadjuvant therapies or direct to surgery for primary T4 colonic cancer. Based on PRISMA guidelines, screening and data abstraction were undertaken in duplicate. Quality assessment was carried out using Cochrane risk-of-bias tools. Random-effects models were used to pool effect estimates. This study compared pathological resection margins, postoperative morbidity, and oncological outcomes of cancer recurrence and overall survival.

RESULTS

Four studies with a total of 43 063 patients met the inclusion criteria. Compared with direct to surgery, neoadjuvant therapy was associated with increased rates of margin-negative resection (odds ratio (OR) 2.60, 95 per cent c.i. 1.12 to 6.02; n = 15 487) and 5-year overall survival (pooled hazard ratio 1.42, 1.10 to 1.82, I2 = 0 per cent; n = 15 338). No difference was observed in rates of cancer recurrence (OR 0.42, 0.15 to 1.22; n = 131), 30-day minor (OR 1.12, 0.68 to 1.84; n = 15 488) or major (OR 0.62, 0.27 to 1.44; n = 15 488) morbidity, or rates of treatment-related adverse effects.

CONCLUSION

Compared with direct to surgery, neoadjuvant therapy improves margin-negative resection rates and overall survival.

Rectal cancer radiotherapy

We present the updated recommendations of the French society of oncological radiotherapy for rectal cancer radiotherapy. The standard treatment for locally advanced rectal cancer consists in chemoradiotherapy followed by radical surgery with total mesorectal resection and adjuvant chemotherapy according to nodal status. Although this strategy efficiently reduced local recurrences rates below 5% in expert centres, functional sequelae could not be avoided resulting in 20 to 30% morbidity rates. The early introduction of neoadjuvant chemotherapy has proven beneficial in recent trials, in terms of recurrence free and metastasis free survivals. Complete pathological responses were obtained in 15% of tumours treated by chemoradiation, even reaching up to 30% of tumours when neoadjuvant chemotherapy is associated to chemoradiotherapy. These good results question the relevance of systematic radical surgery in good responders. Personalized therapeutic strategies are now possible by improved imaging modalities with circumferential margin assessed by magnetic resonance imaging, by intensity modulated radiotherapy and by refining surgical techniques, and contribute to morbidity reduction. Keeping the same objectives, ongoing trials are now evaluating therapeutic de-escalation strategies, in particular rectal preservation for good responders after neoadjuvant treatment, or radiotherapy omission in selected cases (Greccar 12, Opera, Norad).

Texture analysis imaging "what a clinical radiologist needs to know"

Texture analysis has arisen as a tool to explore the amount of data contained in images that cannot be explored by humans visually. Radiomics is a method that extracts a large number of features from radiographic medical images using data-characterisation algorithms. These features, termed radiomic features, have the potential to uncover disease characteristics. The goal of both radiomics and texture analysis is to go beyond size or human-eye based semantic descriptors, to enable the non-invasive extraction of quantitative radiological data to correlate them with clinical outcomes or pathological characteristics. In the latest years there has been a flourishing sub-field of radiology where texture analysis and radiomics have been used in many settings. It is difficult for the clinical radiologist to cope with such amount of data in all the different radiological sub-fields and to identify the most significant papers. The aim of this review is to provide a tool to better understand the basic principles underlining texture analysis and radiological data mining and a summary of the most significant papers of the latest years.

[Rectal Cancer: Organ preservation and neoadjuvant treatment escalation]

Standard treatment consisting of chemoradiotherapy followed by radical surgery with total mesorectal excision, results in good oncologic local control but high morbidity and poor functional results. Since chemoradiotherapy results in 15% pathological complete response, even reaching up to 30% in case of association with neoadjuvant chemotherapy, radical surgery has been recently debated for good responders. Therefore, a de-escalation strategy, by omitting radical surgery in good responders, has recently been developed with two different options: a watch and wait strategy, requiring an accurate clinical and radiological definition of complete response and a local excision strategy including patients with sub-complete response. Ongoing trials focus on response optimization by chemotherapy intensification or radiotherapy dose escalation. However, many questions are still to be answered regarding definition of complete response, follow-up strategy, morbidity of salvage surgery in case of recurrence as well as long-term oncological and functionnal results.

The impact of pelvic radiotherapy on the gut microbiome and its role in radiation-induced diarrhoea: a systematic review

Pelvic radiotherapy is the key treatment for pelvic malignancies, usually including pelvic primary tumour lesions and lymphatic drainage areas in the pelvic region. Therefore, the intestinal tract in the radiation field is inevitably damaged, a phenomenon clinically referred to as radiation enteritis, and diarrhoea is the most common clinical symptom of radiation enteritis. Therefore, it is necessary to study the mechanism of radiation-induced diarrhoea. It has been found that the gut microbiome plays an important role in the development of diarrhoea in response to pelvic radiotherapy, and the species and distribution of intestinal microbiota are significantly altered in patients after pelvic radiotherapy. In this study, we searched for articles indexed in the Cochrane Library, Web of Science, EMBASE and PubMed databases in English and CNKI, Wanfang data and SINOMED in Chinese from their inception dates through 13 March 2020 to collect studies on the gut microbiome in pelvic radiotherapy patients. Eventually, we included eight studies: one study report on prostatic carcinoma, five studies on gynaecological carcinoma and two papers on pelvic carcinomas. All studies were designed as self-controlled studies, except for one that compared toxicity to nontoxicity. The results from all the studies showed that the diversity of intestinal flora decreased during and after pelvic radiotherapy, and the diversity of intestinal flora decreased significantly in patients with diarrhoea after radiotherapy. Five studies observed that the community composition of the gut microbiota changed at the phylum, order or genus level before, during, and after pelvic radiotherapy at different time points. In addition, the composition of the gut microbiota before radiotherapy was different between patients with postradiotherapy diarrhoea and those without diarrhoea in five studies. However, relevant studies have not reached consistent results regarding the changes in microbiota composition. Changes in the intestinal flora induced by pelvic radiotherapy and their relationship between changes in intestinal flora and the occurrence of radiation-induced diarrhoea (RID) are discussed in this study, providing a theoretical basis for the causes of RID after pelvic radiotherapy.

The Impact of Gut Microbiota on Radiation-Induced Enteritis

Radiotherapy is an important treatment for abdominal tumors. A critical side effect for this therapy is enteritis. In this review, we aim to summarize recent findings in radiation enteritis, in particular the role of gut microbiota dysbiosis in the development and therapy of the disease. Gut microbiota dysbiosis plays an important role in the occurrence of various diseases, such as radiation enteritis. Abdominal radiation results in changes in the composition of microbiota and reduces its diversity, which is mainly reflected in the decrease of Lactobacillus spp. and Bifidobacterium spp. and increase of Escherichia coli and Staphylococcus spp. Gut microbiota dysbiosis aggravates radiation enteritis, weakens intestinal epithelial barrier function, and promotes inflammatory factor expression. Pathogenic Escherichia coli induce the rearrangement and redistribution of claudin-1, occludin, and ZO-1 in tight junctions, a critical component in intestinal epithelial barrier. In view of the role that microbiome plays in radiation enteritis, we believe that intestinal flora could be a potential biomarker for the disease. Correction of microbiome by application of probiotics, fecal microbiota transplantation (FMT), and antibiotics could be an effective method for the prevention and treatment of radiation-induced enteritis.

Proton beam therapy in rectal cancer: A systematic review and meta-analysis

INTRODUCTION

Locally advanced rectal cancer is often treated with neoadjuvant chemoradiotherapy and surgery. Radiotherapy carries significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) has demonstrated to be effective in other cancers, delivering equivalent dosimetric radiation but with the benefit of improved sparing of OAR. This review compares dosimetric irradiation of OAR and oncological outcomes for PBT versus conventional photon-based radiotherapy in locally advanced rectal cancer.

METHODS

An electronic literature search was performed for studies with comparative cohorts receiving proton beam therapy and photon-based radiotherapy for rectal cancer.

RESULTS

Eight articles with a total of 127 patients met the inclusion criteria. There was significantly less irradiated small bowel with PBT compared to three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) (MD -17.01, CI [-24.06, -9.96], p < 0.00001 and MD -6.96, CI [-12.99, -0.94], p = 0.02, respectively). Similar dosimetric results were observed for bladder and pelvic bone marrow. Three studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43 %, 68 % and 77.2 %, and one study in primary rectal cancer with 100 % disease free survival.

CONCLUSION

PBT treatment plans revealed significantly less irradiation of OAR for rectal cancer compared to conventional photon-based radiotherapy. Trials for recurrent rectal cancer and PBT have shown promising results. There are currently no ongoing clinical trials for primary rectal cancer and PBT. More research is required to validate its potential role in dose escalation, higher complete response rate and organ preservation without increasing toxicity.

A Prospective Observational Study Comparing Long-Course Conventional Neoadjuvant Chemoradiotherapy with Short-Course Radiotherapy Followed by Consolidation Chemotherapy with Delayed Surgery in Locally Advanced Rectal Cancer

Background  Polish and Australian randomized studies compared short-course radiotherapy (RT) with immediate surgery and long-course chemoradiotherapy (CRT) with delayed surgery. In these studies, similar long-term survival and local control have been reported for both these approaches, but pathological complete response (pCR) is not better with short-course RT. Moreover, studies have shown better tumor downstaging with delayed surgery. In this context, the use of short-course RT with delayed surgery may have some advantages and needs to be tested in clinical trials. Patients and Methods  This was a two-arm, prospective, observational study, in which preoperative short-course RT followed by two cycles of chemotherapy was compared with the conventional neoadjuvant CRT in locally advanced rectal cancer. The primary end points were the rate of complete response and toxicity profile. The secondary end points were the rate of R0 resection, overall survival, and progression-free survival. The data obtained from the two arms were analyzed using Pearson's chi-square test to determine the statistical significance between the two treatment arms. Results  The pCR rate was 6.7% in the study arm and 0 in the control arm ( p = 0.343). The RO resection rates were 92.8 and 92.3% in the study and control arms, respectively. The rates of grade 3and 4 acute toxicity in the study and control arms were 14.2 and 61.5%, respectively ( p = 0.011). The rates of grade 3 and 4 late toxicity in the study and control arms were 21.4 and 15.3%, respectively ( p = 0.686). Conclusions  The pCR rates and the late toxicities in both arms are comparable. The major advantages of the 5 × 5 Gy regimen with chemotherapy in a neoadjuvant setting are a significant reduction in acute toxicities and better patient compliance along with similar efficacy as that of the standard regimen.

Role of radiotherapy in the treatment of rectal cancer in older patients

Striking a balance between cancer treatment and patient-centred care is becoming ever more important in older patients with rectal cancer as the population is ageing. The treatment decision made by the modern multidisciplinary colorectal team will recommend pre-operative chemo-radiotherapy followed by surgery for advance rectal cancer and surgery alone for early rectal cancer, as the "standard of care" is surgery. However, an alternative non-surgical treatment option should be consider for older patients with rectal cancer as the surgical harm can far outweigh the potential benefits. There is published evidence that mortality is higher with increasing age. An alternative treatment option to surgery when patients are not suitable or refusing surgery is to offer them external beam radiotherapy (EBRT) or chemo radiotherapy (EBCRT). A proportion of these patients can achieve a clinical complete response (cCR) which enable adoption of 'watch and wait' strategy to avoid surgery. However, a third of patients who achieved initial cCR can develop local regrowth within the first two years. This require salvage surgery which reduces their chance of organ preservation. Contact X-ray brachytherapy (CXB) or High Dose Rate Endo Brachy Therapy (HDREBT) boost following external beam radiotherapy can improve the initial cCR rate and reduce the risk of local regrowth. Those patients with persistent residual cancer or regrowth after brachytherapy boost following EBCRT or EBRT can have salvage surgery later without compromising their chance of cure. Therefore, patients should be fully aware of their treatment options and have 'a choice' when deciding and consenting their treatment.

The Effects of Probiotic Supplementation on the Incidence of Diarrhea in Cancer Patients Receiving Radiation Therapy: A Systematic Review with Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

The protective effects of probiotic supplementation against radiation-induced diarrhea (RID) have been reported in previous systematic reviews; however so far, only non-conclusive results have been obtained. The objective of this study was to systematically update and evaluate the available evidence for probiotic supplementation. The protocol of this systematic review has been registered (CRD42018106059) with the International Prospective Register of Systematic Reviews (PROSPERO). The primary efficacy outcome was the incidence of RID. Secondary outcomes were the incidence of watery stool, soft stool, and antidiarrheal medication use. There were eight trials, and a total of 1116 participants were included in the primary analysis. Compared with placebo, probiotics were associated with a lower risk of RID [risk ratio (RR) = 0.62, 95% CI = 0.46, 0.83]. A requisite heterogeneity-adjusted trial sequential analysis indicated conclusive evidence for this beneficial effect. No statistically significant reduction in RID (RR = 0.52, 95% CI = 0.14, 1.91) was observed on subgroup analysis in patients receiving both radiation therapy and chemotherapy. However, those patients receiving only radiation therapy (RT) demonstrated significant benefit (RR = 0.61, 95% CI = 0.48, 0.78). There was a significant difference in the antidiarrheal medication use (RR = 0.54, 95% CI = 0.35, 0.84) observed with the use of probiotics. However, no significant difference was observed for the incidence of soft and watery stool. The use of probiotics is beneficial in preventing RID in patients receiving RT.

Neoadjuvant volumetric modulated arc radiochemotherapy with a simultaneous integrated boost technique compared to standard chemoradiation for locally advanced rectal cancer

Background/aim

The present study aimed to examine whether the combination of neoadjuvant volumetric modulated arc radiotherapy (VMAT) using simultaneous integrated boost (SIB-VMAT) techniques and chemotherapy with capecitabine is associated with better clinical and dosimetric outcomes compared to the standard treatment.

Materials and methods

The study included 59 patients with cT2–T4 rectal cancer. In the standard arm, patients (n = 37) were treated preoperatively with image-guided VMAT plus capecitabine. In the SIB arm, patients (n = 22) were treated with the SIB-VMAT technique plus capecitabine. All patients underwent radical surgical resection after neoadjuvant radiochemotherapy.

Results

In the standard arm, cT0N0 was reached in 12 patients (32.4%), primary tumor clinical downstaging was observed in 22 patients (59.5%), and disease stability was achieved in 3 patients (8.1%). In the SIB arm, cT0N0 was reached in 15 patients (68.2%), primary tumor clinical downstaging was observed in 6 patients (27.3%), and disease stability was achieved in 1 patient (4.5%) (P = 0.028). Complete pathological response was observed in 11 patients (29.7%) in the standard arm and in 13 patients (59.1%) in the SIB arm (P = 0.026). In the SIB arm mild diarrhea appeared in 59.1%, moderate in 40.9%, and severe in 0% of the cases. In the standard arm mild, moderate, and severe diarrhea rates were in 54.1%, 43.2%, and 2.7%, respectively. In the SIB arm mild, moderate, and severe cystitis appeared in 63.6%, 22.7%, and 13.6%, while in the standard group mild cystitis developed in 67.6%, moderate in 24.3%, and severe in 8.1%. Mild, moderate, and severe radiation dermatitis rates were 45.5%, 45.5%, and 9.1% in the SIB group and 40.5%, 48.6%, and 10.8% in the standard group, respectively.

Conclusion

The SIB-VMAT technique is effective and safe for irradiating locally advanced rectal cancer. Its effectiveness is expressed in higher clinical and pathological complete response rates and safety with the same rates of acute toxicity.

The 2017 Assisi Think Tank Meeting on rectal cancer: A positioning paper

BACKGROUND AND PURPOSES

To describe current practice in the management of rectal cancer, to identify uncertainties that usually arise in the multidisciplinary team (MDT)'s discussions ('grey zones') and propose next generation studies which may provide answers to them.

MATERIALS AND METHODS

A questionnaire on the areas of controversy in managing T2, T3 and T4 rectal cancer was drawn up and distributed to the Rectal-Assisi Think Tank Meeting (ATTM) Expert European Board. Less than 70% agreement on a treatment option was indicated as uncertainty and selected as a 'grey zone'. Topics with large disagreement were selected by the task force group for discussion at the Rectal-ATTM.

RESULTS

The controversial clinical issues that had been identified within cT2-cT3-cT4 needed further investigation. The discussions focused on the role of (1) neoadjuvant therapy and organ preservation on cT2-3a low-middle rectal cancer; (2) neoadjuvant therapy in cT3 low rectal cancer without high risk features; (3) total neoadjuvant therapy, radiotherapy boost and the best chemo-radiotherapy schedule in T4 tumors. A description of each area of investigation and trial proposals are reported.

CONCLUSION

The meeting successfully identified 'grey zones' and, in the light of new evidence, proposed clinical trials for treatment of early, intermediate and advanced stage rectal cancer.

Adjuvant Chemotherapy Improves Survival Following Resection of Locally Advanced Rectal Cancer with Pathologic Complete Response

BACKGROUND

Controversy exists over the use of adjuvant chemotherapy for locally advanced (stages II-III) rectal cancer (LARC) patients who demonstrate pathologic complete response (pCR) following neoadjuvant chemoradiation. We conducted a retrospective analysis to determine whether adjuvant chemotherapy imparts survival benefit among this population.

METHODS

The National Cancer Database (NCDB) was queried to identify LARC patients with pCR following neoadjuvant chemoradiation. The cohort was stratified by receipt of adjuvant chemotherapy. Multiple imputation and a Cox proportional hazards model were employed to estimate the effect of adjuvant chemotherapy on overall survival.

RESULTS

There were 24,418 patients identified in the NCDB with clinically staged II or III rectal cancer who received neoadjuvant chemoradiation. Of these, 5606 (23.0%) had pCR. Among patients with pCR, 1401 (25%) received adjuvant chemotherapy and 4205 (75%) did not. Patients who received adjuvant chemotherapy were slightly younger, more likely to have private insurance, and more likely to have clinically staged III disease, but did not differ significantly in comparison to patients who did not receive adjuvant chemotherapy with respect to race, sex, facility type, Charlson comorbidity score, histologic tumor grade, procedure type, length of stay, or rate of 30-day readmission following surgery. On adjusted analysis, receipt of adjuvant chemotherapy was associated with a lower risk of death at a given time compared to patients who did not receive adjuvant chemotherapy (HR 0.808; 95% CI 0.679-0.961; p = 0.016).

CONCLUSION

Supporting existing NCCN guidelines, the findings from this study suggest that adjuvant chemotherapy improves survival for LARC with pCR following neoadjuvant chemoradiation.

Oxaliplatin with Raltitrexed and Preoperative Radiotherapy in T3-T4 Extraperitoneal Rectal Cancer. A Dose Finding Study

Aims and background

The availability of new drugs offers the opportunity to improve the outcome of locally advanced rectal cancer. Raltitrexed and oxaliplatin are effective in advanced colorectal cancer with acceptable toxicity and can act as radiation enhancers as shown in phase 1-11 studies. The aim of the study was thus to determine the recommended dose of oxaliplatin concomitantly administered with raltitrexed and concurrent preoperative radiotherapy in patients with stage 11-111 extraperitoneal rectal cancer.

Methods

From September 2001 to September 2002, 18 consecutive patients with T3/T4 rectal cancer were treated at our Institution with preoperative chemoradiation followed by surgery after 6-8 weeks. Pelvic radiotherapy was delivered at a dose of 45 Gy in 25 fractions in 5 weeks followed by a 5.4 Gy boost at 1.8 Gy daily. Concomitant chemotherapy consisted of 3 mg/m2/iv of raltitrexed on days 1, 19, 38 of radiotherapy treatment with incremental doses of oxaliplatin according to dose finding rules (4 dose levels: 65, 85, 110, 130 mg/m2). Dose-limiting toxicity for oxaliplatin was defined as either grade 3-4 hematological or grade 3-4 gastrointestinal or neurological toxicity. We studied a minimum of 3 patients at each dose level.

Results

Three patients were treated at 65, 85, and 110 mg/m2/iv, respectively, while 9 patients were recruited at the last dose level. Neither grade 3-4 gastrointestinal nor neurological toxicity were documented. Dose-limiting toxicity was documented in 2/9 subjects at the 130 mg/m2 level consisting of grade 3 transient asymptomatic leukopenia. Thirteen patients developed transient increase of one or more liver enzymes (grade 3-4) and 2 patients developed grade 3 perineal dermatitis. All patients received the programmed dose of radiotherapy. The chemotherapy regimen was not completed in 4 cases due to grade 2 protracted leukopenia.

Conclusions

The maximum tolerated dose of oxaliplatin was not reached at the maximum dose level (IV); 130 mg/m2 can therefore be defined as the recommended dose. The combination of oxaliplatin with raltitrexed and radiotherapy can be considered feasible and well tolerated.

Systematic review and meta-analysis of small bowel dose-volume and acute toxicity in conventionally-fractionated rectal cancer radiotherapy

INTRODUCTION

The limited radiation tolerance of the small-bowel causes toxicity for patients receiving conventionally-fractionated radiotherapy for rectal cancer. Safe radiotherapy dose-escalation will require a better understanding of such toxicity. We conducted a systematic review and meta-analysis using published datasets of small bowel dose-volume and outcomes to analyse the relationship with acute toxicity.

MATERIALS AND METHODS

SCOPUS, EMBASE & MEDLINE were searched to identify twelve publications reporting small-bowel dose-volumes and toxicity data or analysis. Where suitable data were available (mean absolute volume with parametric error measures), fixed-effects inverse-variance meta-analysis was used to compare cohorts of patients according to Grade ≥3 toxicity. For other data, non-parametric examinations of irradiated small-bowel dose-volume and incidence of toxicity were conducted, and a univariate logistic regression model was fitted.

RESULTS

On fixed-effects meta-analysis of three studies (203 patients), each of the dose-volume measures V_5Gy-V_40Gy were significantly greater (p < 0.00001) for patients with Grade ≥3 toxicity than for those without. Absolute difference was largest for the lowest dose-volume parameter; however relative difference increases with increasing dose. On logistic regression multiple small-bowel DVH parameters were predictive of toxicity risk (V_5Gy, V_10Gy, V_30Gy - V_45Gy), with V_10Gy the strongest (p = 0.004).

CONCLUSIONS

Analysis of published clinical cohort dose-volume data provides evidence for a significant dose-volume-toxicity response effect for a wide range of clinically-relevant doses in the treatment of rectal cancer. Both low dose and high dose are shown to predict toxicity risk, which has important implications for radiotherapy planning and consideration of dose escalation for these patients.

Preoperative radiotherapy and curative surgery for the management of localised rectal carcinoma

BACKGROUND

This is an update of the original review published in 2007.Carcinoma of the rectum is a common malignancy, especially in high income countries. Local recurrence may occur after surgery alone. Preoperative radiotherapy (PRT) has the potential to reduce the risk of local recurrence and improve outcomes in rectal cancer.

OBJECTIVES

To determine the effect of preoperative radiotherapy for people with localised resectable rectal cancer compared to surgery alone.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; Issue 5, 2018) (4 June 2018), MEDLINE (Ovid) (1950 to 4 June 2018), and Embase (Ovid) (1974 to 4 June 2018). We also searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) for relevant ongoing trials (4 June 2018).

SELECTION CRITERIA

We included randomised controlled trials comparing PRT and surgery with surgery alone for people with localised advanced rectal cancer planned for radical surgery. We excluded trials that did not use contemporary radiotherapy techniques (with more than two fields to the pelvis).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the 'Risk of bias' domains for each included trial, and extracted data. For time-to-event data, we calculated the Peto odds ratio (Peto OR) and variances, and for dichotomous data we calculated risk ratios (RR) using the random-effects method. Potential sources of heterogeneity hypothesised a priori included study quality, staging, and the use of total mesorectal excision (TME) surgery.

MAIN RESULTS

We included four trials with a total of 4663 participants. All four trials reported short PRT courses, with three trials using 25 Gy in five fractions, and one trial using 20 Gy in four fractions. Only one study specifically required TME surgery for inclusion, whereas in another study 90% of participants received TME surgery.Preoperative radiotherapy probably reduces overall mortality at 4 to 12 years' follow-up (4 trials, 4663 participants; Peto OR 0.90, 95% CI 0.83 to 0.98; moderate-quality evidence). For every 1000 people who undergo surgery alone, 454 would die compared with 45 fewer (the true effect may lie between 77 fewer to 9 fewer) in the PRT group. There was some evidence from subgroup analyses that in trials using TME no or little effect of PRT on survival (P = 0.03 for the difference between subgroups).Preoperative radiotherapy may have little or no effect in reducing cause-specific mortality for rectal cancer (2 trials, 2145 participants; Peto OR 0.89, 95% CI 0.77 to 1.03; low-quality evidence).We found moderate-quality evidence that PRT reduces local recurrence (4 trials, 4663 participants; Peto OR 0.48, 95% CI 0.40 to 0.57). In absolute terms, 161 out of 1000 patients receiving surgery alone would experience local recurrence compared with 83 fewer with PRT. The results were consistent in TME and non-TME studies.There may be little or no difference in curative resection (4 trials, 4673 participants; RR 1.00, 95% CI 0.97 to 1.02; low-quality evidence) or in the need for sphincter-sparing surgery (3 trials, 4379 participants; RR 0.99, 95% CI 0.94 to 1.04; I² = 0%; low-quality evidence) between PRT and surgery alone.Low-quality evidence suggests that PRT may increase the risk of sepsis from 13% to 16% (2 trials, 2698 participants; RR 1.25, 95% CI 1.04 to 1.52) and surgical complications from 25% to 30% (2 trials, 2698 participants; RR 1.20, 95% CI 1.01 to 1.42) compared to surgery alone.Two trials evaluated quality of life using different scales. Both studies concluded that sexual dysfunction occurred more in the PRT group. Mixed results were found for faecal incontinence, and irradiated participants tended to resume work later than non-irradiated participants between 6 and 12 months, but this effect had attenuated after 18 months (low-quality evidence).

AUTHORS' CONCLUSIONS

We found moderate-quality evidence that PRT reduces overall mortality. Subgroup analysis did not confirm this effect in people undergoing TME surgery. We found consistent evidence that PRT reduces local recurrence. Risk of sepsis and postsurgical complications may be higher with PRT.The main limitation of the findings of the present review concerns their applicability. The included trials only assessed short-course radiotherapy and did not use chemotherapy, which is widely used in the contemporary management of rectal cancer disease. The differences between the trials regarding the criteria used to define rectal cancer, staging, radiotherapy delivered, the time between radiotherapy and surgery, and the use of adjuvant or postoperative therapy did not appear to influence the size of effect across the studies.Future trials should focus on identifying participants that are most likely to benefit from PRT especially in terms of improving local control, sphincter preservation, and overall survival while reducing acute and late toxicities (especially rectal and sexual function), as well as determining the effect of radiotherapy when chemotherapy is used and the optimal timing of surgery following radiotherapy.

Comparative Outcomes of Preoperative Chemoradiotherapy and Selective Postoperative Chemoradiotherapy in Clinical Stage T3N0 Low and Mid Rectal Cancer

Purpose/aim: Preoperative chemoradiotherapy (pre-CRT) and total mesorectal excision (TME) have become the standard of care for patients with locally advanced rectal cancer (LARC). Nevertheless, it is a controversial issue whether pre-CRT in cT3N0M0 patients would result in potential overtreatment. Materials and methods: In total, 183 clinical stage IIA rectal cancer patients treated with and without pre-CRT between 2011 and 2014 were retrospectively analyzed. Capecitabine/FOLFOX/CAPOX chemotherapy was co-administered with preoperative radiotherapy. Surgical resection with laparoscopic or open TME was conducted 8-12 weeks after completion of the pre-CRT. Postoperative radiotherapy was routinely given to patients with pT4 lesion or circumferential margin (CRM) and/or distal resection margin (DRM) involvement. Results: In total, 108 (59%) patients received pre-CRT and 75 (41%) underwent surgery first. The pre-CRT patients presented with less-advanced pathological T stage tumors compared with the surgery-first patients (p < 0.001). However, the pathological N stage was not significantly different between the two groups (p = 0.065). The 3-year overall survival (OS), disease-free survival (DFS), and 2-year local recurrence (LR) rate were similar in the pre-CRT and surgery-first patients (88.4 versus 88.7%, p = 0.552; 79.6 versus 83.3%, p = 0.797; 2.8 versus 2.7%, p = 0.960, respectively). Cox regression analysis showed that pN stage and CRM/DRM involvement were independently correlated with an unfavorable DFS. Conclusions: In this study, the omission of pre-CRT in cT3N0M0 patients did not translate into a worse oncological outcome. Postoperative radiotherapy should remain a standard option for patients with CRM/DRM involvement and pathological T4 tumors. A generalized indication for pre-CRT in cT3N0 patients is likely to result in overtreatment.

Preoperative short-course radiotherapy and long-course radiochemotherapy for locally advanced rectal cancer: Meta-analysis with trial sequential analysis of long-term survival data

Background and purpose

The role of preoperative short-course radiotherapy (SCRT) in rectal cancer treatment, when compared to long-course radiochemotherapy (LCRT), is still controversial. Thus the meta-analysis with trial sequential analysis (TSA) was performed to evaluate the long-term survival of SCRT and LCRT as therapeutic regimens for locally advanced rectal cancer.

Material and methods

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched up to August 2017 for eligible studies. Hazard ratios (HRs) or odds ratios (ORs) of overall survival (OS), disease free survival (DFS) and local recurrence (LR) with the corresponding 95% confidence intervals (CIs) were calculated and TSA was applied.

Results

11 studies with 1984 patients were included. There was no significant difference in OS (HR = 0.92, 95% CI: 0.75–1.13, p = 0.44), DFS (HR = 0.94, 95% CI: 0.79–1.12, p = 0.50) and LR (OR = 0.73, 95% CI: 0.49–1.08, p = 0.11) between SCRT and LCRT groups. TSA suggested firm evidence for lacking on average a -10% relative risk reduction (RRR) in 4-year OS but no statistical significance in 4-year DFS.

Conclusions

Preoperative SCRT is as effective as LCRT for locally advanced colorectal cancer in long-term survival. SCRT could be preferential while facing long waiting lists or lacking medical resource.

Area of residual tumor is a robust prognostic marker for patients with rectal cancer undergoing preoperative therapy

The aim of this study was to elucidate differences in the histological features of rectal cancer between patients treated with preoperative chemoradiotherapy and those treated with preoperative chemotherapy. Area of residual tumor (ART) was also evaluated for its utility as a potential prognostic marker between them. Sixty‐eight patients with rectal cancer who underwent sphincter‐saving surgery were enrolled in this study. Of these, 39 patients received preoperative chemoradiotherapy (CRT group) and 29 patients received preoperative (neoadjuvant) chemotherapy (NAC group). Area of residual tumor was determined by using morphometric software. Tumors in the two groups were compared for differences in their histological features and clinical outcomes. Tumors in the CRT and NAC groups varied greatly with regard to their histological features after preoperative therapy. Tumors in the CRT group showed more marked fibrosis than those in the NAC group. The total ART were significantly smaller in tumors in the CRT group than those in the NAC group. However, in circumferential resection margin‐negative pathologic stage 0‐III cases, clinical outcomes were not statistically different between the CRT and NAC groups. Both ART and pathologic TNM classification were associated with clinical outcome in preoperative CRT and NAC groups, but Dworak regression grade and fibrotic change were not. Tumors in those undergoing preoperative CRT and NAC were shown to differ significantly in their histological features. Area of residual tumor‐based assessment may provide useful prognostic information, regardless of preoperative therapy.

Proteomic profiling of rectal cancer reveals acid ceramidase is implicated in radiation response

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is used in locally advanced rectal cancer when tumours threaten the circumferential resection margin, with varying response to treatment. This experimental study aimed to identify significantly differentially expressed proteins between patients responding and not responding to CRT, and to validate any proteins of interest.

METHODS

Mass spectrometry (with isobaric tagging for relative quantification) analysis of rectal cancers pre- and post-CRT, and at resection. Validation of proteins of interest was performed by assessing tissue microarray (TMA) immunohistochemistry expression in a further 111 patients with rectal cancer.

RESULTS

Proteomic data are available via ProteomeXchange with identifier PXD008436. Reduced abundance of contributing peptide ions for acid ceramidase (AC) (log fold change -1.526, p = 1.17E-02) was observed in CRT responders. Differential expression of AC was confirmed upon analysis of the TMAs. Cancer site expression of AC in stromal cells from post-CRT resection specimens was observed to be relatively low in pathological complete response (p = 0.003), and relatively high with no response to CRT (p = 0.017).

CONCLUSION

AC may be implicated in the response of rectal cancer to CRT. We propose its further assessment as a novel potential biomarker and therapeutic target.

SIGNIFICANCE

There is a need for biomarkers to guide the use of chemoradiotherapy in rectal cancer, as none are in routine clinical use. We have determined acid ceramidase may have a role in radiation response, based on novel proteomic profiling and validation in a wider dataset using tissue microarrays. The ability to predict or improve response would positively select those patients who will derive benefit, prevent delays in the local and systemic management of disease in non-responders, and reduce morbidity associated with chemoradiotherapy.

Optimal oncologic treatment of rectal cancer in patients over 75 years old: Results of a strategy based on oncogeriatric evaluation

BACKGROUND

Few data are available on the management of elderly rectal cancer patients, and especially on the ability to provide optimal oncological treatment. The aim of this study was to determine the feasibility and results of multimodality treatment for rectal cancer in patients 75years and older after simplified comprehensive geriatric assessment (CGA) according to Balducci score.

METHODS

We reviewed the charts of elderly patients who underwent surgery for localized middle or low rectal cancer. Patients were classified into three CGA groups depending on their functional reserve, comorbidities, geriatric syndromes, and life expectancy.

RESULTS

Neoadjuvant therapy was discussed for 27 patients (47%), but only 56% of them were treated, including 8, 7, and 1 patient from CGA groups 1, 2, and 3, respectively. Fifty-three patients (93%) underwent sphincter-preserving surgical resection and four patients underwent abdominoperineal resection (7%). Postoperative complications were observed in 21 patients (37%). The postoperative complication rate was correlated non-significantly with age (<85years: 40.6%; ≥85years: 57.1%; P=0.3), and with the CGA (P=0.64). In total, 10 patients (18%) had definitive colostomy, including five anastomotic leakages (9%), and one incontinence (2%). The total rate of sphincter preservation was 82% (n=47). The risk of secondary definitive colonic stoma formation was not correlated with CGA (group 1: 14%; group 2/3: 16%; P=0.8). Estimated OS at five years was 52%.

CONCLUSIONS

After routine geriatric assessment, elderly rectal cancer patients have good rates of sphincter conservation and acceptable morbidity/mortality.

Preoperative Chemoradiotherapy for Rectal Cancer in Patients Aged 75 Years and Older: Acute Toxicity, Compliance with Treatment, and Early Results

PURPOSE

Treatment of locally advanced rectal cancer (T3-T4 or N+) is based on short-course radiotherapy (RT) or chemoradiotherapy (CRT) followed by surgery. It is estimated that 30-40 % of rectal cancer occurs in patients aged 75 years or more. Data on adherence to neoadjuvant CRT and its safety remain poor owing to the under-representation of older patients in randomized clinical trials and the discordance in the results from retrospective studies. The aim of this study was to assess adherence with preoperative CRT and tolerability in older patients with a stage II/III unresectable rectal cancer.

METHODS

Patients aged 75 years or more with stage II/III rectal cancer treated with preoperative CRT at the University Hospital of Besancon from 1993 to 2011 were included. Feasibility, toxicities, overall survival, and local recurrence rates were studied.

RESULTS

Fifty-six patients with a Charlson score from 2 to 6 were included. The mean age was 78 years. The compliance rates for RT and chemotherapy were 91 and 41.1 %, respectively. Two patients stopped CRT; one for hemostatic surgery, and one for severe sepsis. For CRT, the rate of grade ≥3 toxicity was 14.29 %, mainly the digestive type. Fifty-two patients underwent tumor resection, including 76.79 % total mesorectal excision resection with 84.6 % complete resection, and a rate of postoperative complications of 39.6 %. At 2 years, the overall survival and local recurrences rates were 87.3 and 7.8 %, respectively.

CONCLUSION

In older patients, selected preoperative CRT, with an adapted chemotherapy dose, is well tolerated. The main toxicity was gastrointestinal. Adherence to RT is comparable to that of younger patients.

Acute Adverse Events and Postoperative Complications in a Randomized Trial of Preoperative Short-course Radiotherapy Versus Long-course Chemoradiotherapy for T3 Adenocarcinoma of the Rectum: Trans-Tasman Radiation Oncology Group Trial (TROG 01.04)

OBJECTIVE

To compare acute adverse events (AE) and postoperative complication rates in a randomized trial of short-course (SC) versus long-course (LC) preoperative radiotherapy.

BACKGROUND

Evidence demonstrates that adding neoadjuvant radiotherapy to surgery offers better local control in the management of rectal cancer. With both SC and LC therapy there is a potential for acute treatment-related toxicity and increased patient morbidity.

METHODS

Eligible patients had clinical-stage T3 rectal adenocarcinoma within 12 cm of the anal verge with no evidence of metastasis. SC consisted of pelvic radiotherapy 5 × 5 Gy in 1 week, early surgery and 6 courses of adjuvant chemotherapy. LC was 50.4 Gy administered in 28 fractions during 5.5 weeks, with infusion 5-fluorouracil, surgery in 4 to 6 weeks, and 4 courses of chemotherapy.

RESULTS

All SC patients and 93% of LC patients received preoperative planned radiotherapy. There was no 30-day operative mortality. A statistically significant higher percentage of at least 1 AE occurred in the LC group (SC, 72.3%; LC, 99.4%; P < 0.001). There were significant differences in favor of SC for grade 3 AE: radiation dermatitis (0% vs 5.6%, P = 0.003), proctitis (0% vs 3.7% P = 0.016), nausea (0% vs 3.1%, P = 0.029), fatigue (0% vs 3.7%, P = 0.016) and grade 3/4 diarrhea rates (1.3% vs 14.2% P < 0.001). No statistically significant differences in surgical complication rates were seen (SC 53.2 vs 50.4% LC, p = 0.68), although permanent stoma (38.0% vs 29.8%, P = 0.13) and anastomotic breakdown (7.1% vs 3.5%, P = 0.26) rates favored LC with perineal wound complications (38.3% vs 50.0%, P = 0.26) in favor of SC.

CONCLUSIONS

LC had significantly higher AEs compared with SC with no statistically significant differences in postoperative complications. There were clinical trends in permanent stoma rates and anastomotic leaks in favor of LC but with an increased perineal wound breakdown rate.

In vivo Portal Imaging Dosimetry Identifies Delivery Errors in Rectal Cancer Radiotherapy on the Belly Board Device

Purpose:

We recently developed a novel, open-source in vivo dosimetry that uses the electronic portal imaging device to detect dose delivery discrepancies. We applied our method on patients with rectal cancer treated on a belly board device.

Methods:

In vivo dosimetry was performed on 10 patients with rectal cancer treated prone on the belly board with a 4-field box arrangement. Portal images were acquired approximately once per week from each treatment beam. Our dosimetry method used these images along with the planning CT to reconstruct patient planar dose at isocenter depth.

Results:

Our algorithm proved sensitive to dose discrepancies and detected discordances in 7 patients. The majority of these were due to soft tissue differences between planning and treatment, present despite matching to bony anatomy. As a result of this work, quality assurance procedures have been implemented for our immobilization devices.

Conclusion:

In vivo dosimetry is a powerful quality assurance tool that can detect delivery discrepancies, including changes in patient setup and position. The added information on actual dose delivery may be used to evaluate equipment and process quality and to guide for adaptive radiotherapy.

Histological differences between preoperative chemoradiotherapy and chemotherapy for rectal cancer: a clinicopathological study

Pathological studies on the different histological effects between neoadjuvant chemotherapy (NAC) and preoperative chemoradiation therapy (preoperative CRT) have not been performed. The purpose of this study is to elucidate the histological differences in tissue received from NAC and preoperative CRT for rectal cancer to evaluate whether a pathological assessment method used after CRT can be applied for NAC. One hundred and thirty-eight patients were enrolled in this study; 88 patients underwent their operations after preoperative CRT or NAC, and 50 patients underwent surgery only. Residual tumor area was measured using morphometry software and we compared the stromal component of myofibroblasts, immune cells, and vasculature to elucidate the difference of therapeutic effect between them. The grade of reduction after preoperative CRT was more prominent than that seen in NAC. Also, ypT downstaging was more prominent in preoperative CRT than in NAC, and ypN downstaging was more frequent in NAC than in preoperative CRT. Preoperative CRT showed more marked myofibroblasts and fewer immune cells than did NAC, which indicates different effects on the cancer microenvironment. Our histological results suggest different effects between NAC and preoperative CRT on tumor tissue. The best assessment method available for a variable therapeutic protocol should be further investigated.

Aspirin as a neoadjuvant agent during preoperative chemoradiation for rectal cancer

Background:

Recently, many studies have suggested a possible adjuvant role of aspirin in colorectal cancer, reporting a positive prognostic effect with its use in patients with established disease. The aim of this study was to investigate the anticancer effect of aspirin use during preoperative chemoradiation for rectal cancer.

Methods:

Two hundred and forty-one patients with stage II–III rectal cancer and candidates for chemoradiation (CRT) were selected and assigned to two groups: group 1, patients taking aspirin at the time of diagnosis, and group 2, all others. Treatment and oncological outcomes were explored.

Results:

Aspirin use was associated with a higher rate of tumour downstaging (67.6% vs 43.6%, P=0.01), good pathological response (46% vs 19% P<0.001), and a slightly, although not significant, higher rate of complete pathological response (22% vs 13% P=0.196). Aspirin use was also associated with a better 5-year progression-free survival (86.6% vs 67.1% hazard rate (HR)=0.20; 95% CI=0.07–0.60) and overall survival (90.6% vs 73.2% HR=0.21; 95% CI=0.05–0.89). Although chance of local relapse was similar (HR=0.6; 95% CI=0.06–4.5), aspirin use was associated with a lower risk of developing metastasis (HR=0.30; 95% CI=0.10–0.86).

Conclusions:

Aspirin might have anticancer activity against rectal cancer during preoperative CRT. This finding could be clinically relevant and should be further investigated with randomised trials.

[Organ preserving strategies for rectal cancer treatment]

For rectal cancers, the current standard of care consists of chemoradiation followed by radical surgery with total mesorectal excision. Oncologic results are good, especially regarding local recurrence rates, but at the cost of high morbidity rates and poor anorectal, urinary and sexual function results. Since chemoradiation yields 15 to 25% pathological complete response, the role of radical surgery is questioned for patients presenting with good response after chemoradiation and two organ preservation strategies have been offered: watch and wait strategy and local excision strategy. The aim of this review is to give the results of organ preservation after chemoradiotherapy series and to highlight different questions regarding initial patient's selection, complete clinical response definition, risk of mesorectal nodal involvement, follow-up modalities as well as oncologic and functional results.

Multimodal therapy in treatment of rectal cancer is associated with improved survival and reduced local recurrence - a retrospective analysis over two decades

Background

The management of rectal cancer (RC) has substantially changed over the last decades with the implementation of neoadjuvant chemoradiotherapy, adjuvant therapy and improved surgery such as total mesorectal excision (TME). It remains unclear in which way these approaches overall influenced the rate of local recurrence and overall survival.

Methods

Clinical, histological and survival data of 658 out of 662 consecutive patients with RC were analyzed for treatment and prognostic factors from a prospectively expanded single-institutional database. Findings were then stratified according to time of diagnosis in patient groups treated between 1993 and 2001 and 2002 and 2010.

Results

The study population included 658 consecutive patients with rectal cancer between 1993 and 2010. Follow up data was available for 99.6% of all 662 treated patients. During the time period between 2002 and 2010 significantly more patients underwent neoadjuvant chemoradiotherapy (17.6% vs. 60%) and adjuvant chemotherapy (37.9% vs. 58.4%). Also, the rate of reported TME during surgery increased. The rate of local or distant metastasis decreased over time, and tumor related 5-year survival increased significantly with from 60% to 79%.

Conclusion

In our study population, the implementation of treatment changes over the last decade improved the patient’s outcome significantly. Improvements were most evident for UICC stage III rectal cancer.

Systematic review: the role of the gut microbiota in chemotherapy- or radiation-induced gastrointestinal mucositis - current evidence and potential clinical applications

BACKGROUND

Gastrointestinal mucositis is defined as inflammation and/or ulcers of the gastrointestinal tract occurring as a complication of chemotherapy and radiation therapy, and affects about 50% of all cancer patients.

AIM

To assess the role of gut microbiota in the pathogenesis of gastrointestinal mucositis and the potential for manipulations of the microbiota to prevent and to treat mucositis.

METHODS

Search of the literature published in English using Medline, Scopus and the Cochrane Library, with main search terms 'intestinal microbiota', 'bacteremia', 'mucositis', 'chemotherapy-induced diarrhoea', 'chemotherapy-induced mucositis', 'radiotherapy-induced mucositis'.

RESULTS

The gut microbiota plays a major role in the maintenance of intestinal homoeostasis and integrity. Patients receiving cytotoxic and radiation therapy exhibit marked changes in intestinal microbiota, with most frequently, decrease in Bifidobacterium, Clostridium cluster XIVa, Faecalibacterium prausnitzii, and increase in Enterobacteriaceae and Bacteroides. These modifications may contribute to the development of mucositis, particularly diarrhoea and bacteraemia. The prevention of cancer therapy-induced mucositis by probiotics has been investigated in randomised clinical trials with some promising results. Three of six trials reported a significantly decreased incidence of diarrhoea. One trial reported a decrease in infectious complications.

CONCLUSIONS

The gut microbiota may play a major role in the pathogenesis of mucositis through the modification of intestinal barrier function, innate immunity and intestinal repair mechanisms. Better knowledge of these effects may lead to new therapeutic approaches and to the identification of predictive markers of mucositis.

EMVI-positive stage II rectal cancer has similar clinical outcomes as stage III disease following pre-operative chemoradiotherapy

BACKGROUND

Stage II rectal cancers comprise a heterogeneous group, and there is significant variability in practise with regards to adjuvant chemotherapy; the survival benefit of chemotherapy is perceived to be <4% in these patients. However, in recent years, the emergence of additional prognostic factors such as extramural venous invasion (EMVI) suggests that there may be sub-stratification of stage II tumours and, further, we may be under-estimating the benefit adjuvant chemotherapy provides in high-risk patients. This study examined the outcomes of patients with stage II and III rectal cancer to determine whether EMVI status influences disease-free survival (DFS).

PATIENTS AND METHODS

An analysis of a prospectively maintained database was conducted of patients presenting with rectal cancer between 2006 and 2012. All patients underwent curative surgery and had no evidence of metastases at presentation. Clinicopathological factors were compared between stage II and III disease. The primary end point was 3-year DFS; univariate and multivariate analysis was carried out using Cox proportional hazards regression models; hazard ratios (HR) with 95% confidence intervals (CIs) were calculated.

RESULTS

Four hundred and seventy-eight patients were included: 233 stage II; 245 stage III. The prevalence of EMVI was 34.9%; 57 stage II patients (24.5%) and 110 stage III patients (44.9%). On multivariate analysis, only EMVI status was a significant factor for DFS. The adjusted HR for EMVI either alone or in combination with nodal involvement was 2.08 (95% CI 1.10-2.95) and 2.74 (95% CI 1.66-4.52), respectively.

CONCLUSION

EMVI is an independently poor prognostic factor for DFS for both stage II and stage III rectal cancer. These results demonstrate that there is risk-stratification within stage II tumours which affects prognosis. When discussing the use of adjuvant chemotherapy with patients that have EMVI-positive stage II tumours, these results provide evidence for a similarly increased risk of distant failure as stage III disease without venous invasion.

Fluorouracil-based adjuvant chemotherapy after preoperative chemoradiotherapy in rectal cancer: long-term results of the EORTC 22921 randomised study

BACKGROUND

EORTC trial 22921 examined the addition of preoperative or postoperative chemotherapy to preoperative radiotherapy in patients with rectal cancer. After a median follow-up of 5 years, chemotherapy-irrespective of timing-significantly improved local control. Adjuvant chemotherapy did not improve survival, but the Kaplan-Meier curves diverged, suggesting possible delayed benefit. Here, we report the updated long-term results.

METHODS

We randomly assigned patients with clinical stage T3 or T4 resectable rectal cancer to receive preoperative radiotherapy with or without concomitant chemotherapy before surgery followed by either adjuvant chemotherapy or surveillance. Randomisation was done using minimisation with factors of institution, sex, T stage, and distance from the tumour to the anal verge. Study coordinators, clinicians, and patients were aware of assignment. Radiotherapy consisted of 45 Gy to the posterior pelvis in 25 fractions of 1·8 Gy over 5 weeks. Each course of chemotherapy consisted of fluorouracil (350 mg/m(2) per day intravenous bolus) and folinic acid (leucovorin; 20 mg/m(2) per day intravenous bolus). For preoperative chemotherapy, two courses were given (during weeks 1 and 5 of radiotherapy). Adjuvant chemotherapy was given in four cycles, every 3 weeks. The primary endpoint was overall survival. This analysis was done by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00002523.

FINDINGS

1011 patients were randomly assigned to treatment between April, 1993, and March, 2003 (252 to preoperative radiotherapy and 253 to each of the other three groups). After a median follow-up of 10·4 years (IQR 7·8-13·1), 10-year overall survival was 49·4% (95% CI 44·6-54·1) for the preoperative radiotherapy group and 50·7% (45·9-55·2) for the preoperative radiotherapy and chemotherapy group (HR 0·99, 95% CI 0·83-1·18; p=0·91). 10-year overall survival was 51·8% (95% CI 47·0-56·4) for the adjuvant chemotherapy group and 48·4% (43·6-53·0) for the surveillance group (HR 0·91, 95% CI 0·77-1·09, p=0·32). 10-year disease-free survival was 44·2% (95% CI 39·5-48·8) for the preoperative radiotherapy group and 46·4% (41·7-50·9) for the preoperative radiotherapy and chemotherapy group (HR 0·93, 95% CI 0·79-1·10; p=0·38). 10-year disease-free survival was 47·0% (95% CI 42·2-51·6) for the adjuvant chemotherapy group and 43·7% (39·1-48·2) for the surveillance group (HR 0·91, 95% CI 0·77-1·08, p=0·29). At 10 years, cumulative incidence of local relapse was 22·4% (95% CI 17·1-27·6) with radiotherapy alone, 11·8% (7·8-15·8) with neoadjuvant radiotherapy and chemotherapy, 14·5% (10·1-18·9) with radiotherapy and adjuvant chemotherapy and 11·7% (7·7-15·6) with both adjuvant and neoadjuvant chemotherapy (p=0·0017). There was no difference in cumulative incidence of distant metastases (p=0·52). The frequency of long-term side-effects did not differ between the four groups (p=0·22).

INTERPRETATION

Adjuvant fluorouracil-based chemotherapy after preoperative radiotherapy (with or without chemotherapy) does not affect disease-free survival or overall survival. Our trial does not support the current practice of adjuvant chemotherapy after preoperative radiotherapy with or without chemotherapy. New treatment strategies incorporating neoadjuvant chemotherapy are required.

FUNDING

EORTC, US National Cancer Institute, Programme Hospitalier de Recherche Clinique, Ligue contre le Cancer Comité du Doubs.

Preoperative chemoradiation versus radiation alone for stage II and III resectable rectal cancer

BACKGROUND

Preoperative radiotherapy (RT) decreases local recurrence rate and improves survival in stage II and III rectal cancer patients. The combination of chemotherapy with RT has a sound radiobiological rationale, and phase II trials of combined chemoradiation (CRT) have shown promising activity in rectal cancer.

OBJECTIVES

To compare preoperative RT with preoperative CRT in patients with resectable stage II and III rectal cancer.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials, Web of Science, Embase.com, and Pubmed from 1975 until June 2012. A manual search was performed of Ann Surg, Arch Surg, Cancer, J Clin Oncol, Int J Radiat Oncol Biol Phys and the proceedings of ASTRO, ECCO and ASCO from 1990 until June 2012.

SELECTION CRITERIA

Relevant studies randomized resectable stage II or III rectal cancer patients to at least one arm of preoperative RT alone or at least one arm of preoperative CRT.

DATA COLLECTION AND ANALYSIS

Primary outcome parameters included overall survival (OS) at 5 years and local recurrence (LR) rate at 5 years. Secondary outcome parameters included disease free survival (DFS) at 5 years, metastasis rate, pathological complete response rate, clinical response rate, sphincter preservation rate, acute toxicity, postoperative mortality and morbidity, and anastomotic leak rate. Outcome parameters were summarized using the Odds Ratio (OR) and associated 95% confidence interval (CI) using the fixed effects model.

MAIN RESULTS

Five trials were identified and included in the meta-analysis. From one of the included trials only preliminary data are reported. The addition of chemotherapy to preoperative RT significantly increased grade III and IV acute toxicity (OR 1.68-10, P = 0.002) and marginally affected postoperative overall morbidity (OR 0.67-1.00, P = 0.05) while no differences were observed in postoperative mortality or anastomotic leak rate. Compared to preoperative RT alone, preoperative CRT significantly increased the rate of complete pathological response (OR 2.12-5.84, P < 0.00001) although this did not translate into a higher sphincter preservation rate (OR 0.92-1.30, P = 0.32). The incidence of local recurrence at five years was significantly lower in the CRT group compared to RT alone (OR 0.39-0.72, P < 0.001). No statistically significant differences were observed in DFS (OR 0.92-1.34, P = 0.27) or OS (OR 0.79-1.14, P = 0.58) at five years.

AUTHORS' CONCLUSIONS

Compared to preoperative RT alone, preoperative CRT enhances pathological response and improves local control in resectable stage II and III rectal cancer, but does not benefit disease free or overall survival. The effects of preoperative CRT on functional outcome and quality of life are incompletely understood and should be addressed in future trials.

Combination of irinotecan and 5-fluorouracil with radiation in locally advanced rectal adenocarcinoma

OBJECTIVE

To evaluate toxicity and efficacy of addition of weekly irinotecan to a regimen of chemoradiotherapy of 5-fluorouracil with concurrent pelvic radiation in patients with locally advanced rectal cancer.

PATIENTS AND METHODS

Between October 2006 and December 2009, 36 patients with non-metastatic rectal adenocarcinoma were treated with chemoradiotherapy of irinotecan (50 mg/m(2) weekly), 5-fluorouracil (250 mg/m(2) for 5 days/week) and pelvic radiation (45 Gy/1.8 Gy/fraction for 5 days/week) by 3D conformal radiotherapy.

RESULTS

All patients completed the planned treatment. After the chemoradiotherapy, overall clinical response rate was 55.5% and pathological complete was 16.7%. Neutropenia was the most common hematologic toxicity (58.3%) with grade III in 5.5% while among non hematologic toxicity, diarrhea was the most common reported one (63.9%) with grade III in 13.9% followed by nausea and vomiting (47.2%). After a median follow-up of 23 months, progression-free and overall survival estimates at 2 years were 72% and 91.7%, respectively. Distant relapses were recoded in 16.7%, the main distant failure sites were lung and liver, and local relapse was found in 5.6%.

CONCLUSION

Combined chemoradiotherapy of irinotecan, 5-fluorouracil and radiotherapy for locally advanced non metastatic rectal adenocarcinoma is effective and safe. A prospective, randomized trial is needed to confirm these results in larger numbers and to compare this regimen with other non-irinotecan-based chemoradiotherapy regimens.