Comparison of preoperative short-course radiotherapy and long-course radiochemotherapy for locally advanced rectal cancer

Total neoadjuvant therapy in rectal cancer: the evidence and expectations

Current management of locally advanced rectal cancer achieves high cure rates, distant metastatic spread being the main cause of patients' death. Total neoadjuvant therapy (TNT) employs (chemo)radiotherapy and combined chemotherapy prior to surgery to improve the treatment outcomes. TNT has been shown to reduce significantly distant metastases, increase disease-free survival by 5 - 10% in 3 years, and finally also overall survival (≈ 5% in 7 years). It proved to double the rate of pathologic complete responses, making it an attractive strategy for non-operative management to avoid permanent colostomy in patients with distal tumors. In addition, it endorses adherence to the therapy due to better tolerance and, potentially, shortens its overall duration. A number of questions related to TNT remain currently unresolved including the indications, preferred radiotherapy and chemotherapy regimens, their sequence, timing of surgery, and role of adjuvant therapy. A stratified approach may be the optimal way to go.

Comparison of long course and short course preoperative radiotherapy in the treatment of locally advanced rectal cancer: a systematic review and meta-analysis

BACKGROUND

rectal cancer (RC) is one of the most prevalent malignancies worldwide and different preoperative radiotherapies may lead to different outcomes. This meta-analysis aimed to compare the effectiveness of long-course (LC) and short-course radiotherapy (SC), with or without chemotherapy, for locally advanced rectal cancer.

METHODS

studies published up to March 31st 2018 were retrieved from PubMed, Medline, Cochrane and EMABSE. Randomized control or consort control trials that reported the outcomes of short or long course radiotherapy were eligible. Either a fixed or random effects model was used to access the overall combined risk estimates.

RESULTS

sixteen studies with a total of 2,773 RC patients were included in the analysis. There were no significant differences between LC and SC therapies with regard to the following: pathological complete response (PCR) (I2 = 78%, p < 0.05, RR = 0.54, 95% CI: 0.26-1.10); tumor downstaging (I2 = 79%, p < 0.05, RR = 0.83, 95% CI: 0.58-1.17); local recurrences (I2 = 22%, p = 0.27, RR = 0.55, 95% CI: 0.26-1.16); distant metastases (I2 = 29%, p = 0.22, RR = 1.03, 95% CI: 0.77-1.37); mortality (I2 = 0%, p = 0.78, RR = 0.95, 95% CI: 0.78-1.15) and serious late toxicity (I2 = 74%, p = 0.01, RR = 1.10, 95% CI: 0.37-3.26). In the subgroup analysis, LC had a better PCR and tumor downstaging rate compared with SC in the RCT subgroup. Besides, LC also presented a better PCR rate compared with SC without chemotherapy.

CONCLUSIONS

LC and SC are both effective in the preoperative treatment of RC with regard to PCR, tumor downstaging, local recurrences, distant metastases, mortality and serious late toxicity. Furthermore, chemotherapy may enhance the efficacy of preoperative treatment.

Dose-time fractionation schedules of preoperative radiotherapy and timing to surgery for rectal cancer

Chemoradiotherapy (CRT) is extensively used prior to surgery for rectal cancer to provide significantly better local control, but the radiotherapy (RT), as the other component of CRT, has been subject to less interest than the drug component in recent years. With considerable developments in RT, the use of advanced techniques, such as intensity-modulated radiotherapy (IMRT) in rectal cancer, is garnering more attention nowadays. The radiation dose can be better conformed to the target volumes with possibilities for synchronous integrated boost without increased complications in normal tissue. Hopefully, both local recurrence and toxicities can be further reduced. Although those seem to be of interest, many issues remain unresolved. There is no international consensus regarding the radiation schedule for preoperative RT for rectal cancer. Moreover, an enormous disparity exists regarding the RT delivery. With the advent of IMRT, variations will likely increase. Moreover, time to surgery is also quite variable, as it depends upon the indication for RT/CRT in the clinical practices. In this review, we discuss the options and problems related to both the dose-time fractionation schedule and time to surgery; furthermore, it addresses the research questions that need answering in the future.

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.

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.

Short-course neoadjuvant chemoradiotherapy and surgery are beneficial in Chinese patients: A retrospective study

Preoperative neoadjuvant chemoradiotherapy (NACR) is used to reduce tumor size for easier resection or improved resectability rates. Considering the difficulties regarding health insurance and health resources in China, an evidence-based short-course neoadjuvant chemoradiotherapy with surgery to cure patients was performed. This study compared the postoperative effects between short-course neoadjuvant chemoradiotherapy and surgery and surgery without neoadjuvant chemoradiotherapy.The current retrospective study was based on a rectal cancer database, including 274 patients diagnosed with rectal cancer between January 2014 and October 2016. Data were analyzed with respect to curative rate, postoperative recovery indicators (times to nasogastric tube, urinary catheter, and drainage tube removal and times to first oral feeding and passing of flatus postsurgery), chemoradiotherapy-related indicators [white blood cell count (WBC) and carcinoembryonic antigen (CEA) levels], and adverse effects indicators, evaluated according to Common Terminology Criteria for Adverse Events Version 4.0.There was no significant difference between the combined therapy and surgery groups (P > .05) in terms of radical resection rates and the times to urinary catheter removal and passing flatus (P > .05). Statistically significant differences (P < .05) in terms of earlier time for removal of the nasogastric and drainage tubes and time to first oral feeding were observed in the combined therapy group. The decreases in WBC and CEA levels in the combined therapy group were significantly greater than those in the surgery group 1 week after surgery (P < .05); after 1 month, the CEA decrease in the combined therapy group was significantly greater than that in the surgery group (P < .05). More patients in the combined therapy group experienced vomiting, indigestion, dehydration, oral mucositis, sensory neuritis, and alopecia compared with those in the surgery group 1 week after surgery (P < .05); after 1 month, only the incidence of alopecia was higher in the combined therapy group (P < .05).The combined therapy group demonstrated earlier postoperative recovery compared with the surgery group. Short-course neoadjuvant chemoradiotherapy with surgery may lead to postoperative treatment-related adverse effects of varying degrees; however, these adverse effects eventually improve with time.

Pre- and post-surgery treatments in rectal cancer: a long-term single-centre experience

BACKGROUND

Our study evaluated long-term survival outcomes in rectal cancer patients treated with preoperative radiotherapy, and the impact on survival of concomitant and postoperative adjuvant chemotherapy (ctx), among other prognostic factors.

METHODS

The study included 196 patients [median age: 58 years (range: 20-86 years); 63.0% men] with locally advanced rectal carcinoma and, in some cases, resectable liver metastasis. Rates of distant metastasis and local recurrence and of 5-year distant metastasis-free survival (dmfs) and overall survival (os) were determined.

RESULTS

The 5-year os rate was 57.0%, with a median duration of 81.5 months (95% confidence interval: 73.7 months to 89.4 months), and the 5-year dmfs rate was 54.1%, with a median duration of 68.4 months (95% confidence interval: 40.4 months to 96.4 months). Prognostic factors for higher os and dmfs rates were downstaging (p = 0.013 and p = 0.005 respectively), radiotherapy dose (50 Gy vs. 56 Gy or 45-46 Gy, both p = 0.002), and concomitant ctx use (p = 0.004 and p = 0.001) and type (5-fluorouracil-leucovorin-folinic acid vs. tegafur-folinic acid, p = 0.034 and p = 0.043). Adjuvant ctx after neoadjuvant long-term concomitant chemoradiotherapy (ccrt) and surgery was associated with better 5-year os rates for postoperative T0-T3 disease (p = 0.003) and disease at all lymph node stages (p = 0.001).

CONCLUSIONS

Our findings revealed a favourable survival outcome with long-term fractionated irradiation and concomitant 5-fluorouracil-based ctx, achieving 5-year os and dmfs rates of 57.0% and 54.1% respectively. Preoperative administration of radiotherapy (50 Gy) and postoperative adjuvant ctx were associated with a significant survival benefit. Radiation doses above 50 Gy and the interval between ccrt and surgery had no significant effect on survival.

Clinical results and toxicity for short-course preoperative radiotherapy and total mesorectal excision in rectal cancer patients

Short-course preoperative radiotherapy (SCPRT) is an alternative method to chemoirradiation for patients with Stage II and III rectal cancer when no downsizing is needed, but there is still widespread reluctance to use this method because of fear of side effects from high-fraction doses. This paper reports on a single institution patient cohort of operated rectal cancer patients after SCPRT, evaluated for chronic adverse effects, local control, progression-free survival and overall survival. Altogether, 257 patients were treated with SCPRT and surgery including total mesorectal excision (92% total mesorectal excision = TME) between 2002 and 2009. Local control and survival were analyzed. Chronic adverse effects for 154 patients without local relapse were evaluated according to the NCI-CTCAE version 4.0 classification, with a median follow-up of 48 months. We found a 5-year disease-free survival (DFS) and overall survival (OS) of 71%. The 5-year estimated local control (LC) rate was 94%. A positive resection margin was found in 4% of the patients and was significantly correlated with decreased DFS, OS and LC. Chronic adverse effects were reported by 58% of the patients, of which 10% were Grade 3 toxicities. The most frequent Grade 2 toxicity was stool incontinence (13%). Sexual dysfunction was found in 36% of the patients (31% Grade 1 or 2, and only 5% Grade 3). SCPRT combined with TME produced excellent LC rates together with a low rate of high-grade chronic adverse effects.

Human cytomegalovirus and Epstein-Barr virus infection impact on (18)F-FDG PET/CT SUVmax, CT volumetric and KRAS-based parameters of patients with locally advanced rectal cancer treated with neoadjuvant therapy

PURPOSE

It has long been debated whether human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are associated with rectal cancer. The gene products of HCMV and EBV contribute to cell-cycle progression, mutagenesis, angiogenesis and immune evasion. The aim of this prospective study was to analyse the association between infection of a tumour by HCMV and EBV and clinical, histological, metabolic ((18)F-FDG uptake), volumetric (from CT) and molecular (KRAS status) features and long-term outcomes in a homogeneously treated group of patients with locally advanced rectal cancer.

METHODS

HCMV and EBV were detected in pretreatment biopsies using polymerase chain reaction (PCR). The Cox proportional hazards regression model was used to explore associations between viral infection and disease-free survival (DFS) and overall survival (OS).

RESULTS

We analysed 37 patients with a median follow-up of 74 months (range 5-173 months). Locoregional control, OS and DFS at 5 years were 93%, 74% and 71%, respectively. Patients with HCMV/EBV coinfection had a significantly higher maximum standardized uptake value than patients without viral coinfection (p = 0.02). Significant differences were also observed in staging and percentage relative reduction in tumour volume between patients with and without HCMV infection (p < 0.01) and EBV infection (p < 0.01). KRAS wildtype status was significantly more frequently observed in patients with EBV infection (p <0.01) and HCMV/EBV co-infection (p = 0.04). No significant differences were observed in OS or DFS between patients with and without EBV infection (p = 0.88 and 0.73), HCMV infection (p = 0.84 and 0.79), and EBV/CMV coinfection (p = 0.24 and 0.39).

CONCLUSION

This pilot study showed that viral infections were associated with metabolic staging differences, and differences in the evolution of metabolic and volumetric parameters and KRAS mutations. Further findings of specific features will help determine the best candidates for metabolic and volumetric staging and restaging. Further toxicity profile findings will help to determine the best candidates for specific supportive treatment during pelvic chemoradiotherapy in patients with locally advanced rectal cancer.

Dosimetric evaluation of Tomotherapy and four-box field conformal radiotherapy in locally advanced rectal cancer

Purpose

To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer.

Materials and Methods

Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, V_{n Gy}, D_min, D_max, radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose.

Results

Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p = 0.001). But, V_{26.25 Gy} and V_{27.5 Gy}were not significantly different between the two modalities. Tomotherapy showed higher D_max and lower D_min. The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT.

Conclusion

In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.

Neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer

The purpose of this study was to examine the safety and feasibility of a novel protocol of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer. A total of 56 patients with lower rectal cancer of cT3N1M0 (Stage III b) was treated with SC-HART followed by radical surgery, and were analyzed in the present study. SC-HART was performed with a dose of 2.5 Gy twice daily, with an interval of at least 6 hours between fractions, up to a total dose of 25 Gy (25 Gy in 10 fractions for 5 days) combined with S-1 for 10 days. Radical surgery was performed within three weeks following the end of the SC-HART. The median age was 64.6 (range, 39-85) years. The median follow-up term was 16.3 (range, 2-53) months. Of the 56 patients, 53 (94.4%) had no apparent adverse events before surgery; 55 (98.2%) completed the full course of neoadjuvant therapy, while one patient stopped chemotherapy because of Grade 3 gastrointestinal toxicity (CTCAE v.3). The sphincter preservation rate was 94.6%. Downstaging was observed in 45 patients (80.4%). Adjuvant chemotherapy was administered to 43 patients (76.8%). The local control rate, disease-free survival rate and disease-specific survival rate were 100%, 91.1% and 100%, respectively. To conclude, SC-HART combined with S-1 for locally advanced rectal cancer was well tolerated and produced good short-term outcomes. SC-HART therefore appeared to have a good feasibility for use in further clinical trials.