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

ABSTRACT:

Background

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

Methods

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

Results

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

Conclusion

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

SUBMITTER: Wu H

PROVIDER: S-EPMC8785003 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Current standard for most of the locally advanced rectal cancers is preoperative chemoradiotherapy, and, variably per institution, postoperative adjuvant chemotherapy. Short-course preoperative radiation with delayed surgery has been shown to induce tumour down-staging in both randomized and observational studies. The concept of neo-adjuvant chemotherapy has been proven successful in gastric cancer, hepatic metastases from colorectal cancer and is currently tested in primary colon cancer.Patients with rectal cancer with high risk features for local or systemic failure on magnetic resonance imaging are randomized to either a standard arm or an experimental arm. The standard arm consists of chemoradiation (1.8 Gy x 25 or 2 Gy x 25 with capecitabine) preoperatively, followed by selective postoperative adjuvant chemotherapy. Postoperative chemotherapy is optional and may be omitted by participating institutions. The experimental arm includes short-course radiotherapy (5 Gy x 5) followed by full-dose chemotherapy (capecitabine and oxaliplatin) in 6 cycles before surgery. In the experimental arm, no postoperative chemotherapy is prescribed. Surgery is performed according to TME principles in both study arms. The hypothesis is that short-course radiotherapy with neo-adjuvant chemotherapy increases disease-free and overall survival without compromising local control. Primary end-point is disease-free survival at 3 years. Secondary endpoints include overall survival, local control, toxicity profile, and treatment completion rate, rate of pathological complete response and microscopically radical resection, and quality of life.Following the advances in rectal cancer management, increased focus on survival rather than only on local control is now justified. In an experimental arm, short-course radiotherapy is combined with full-dose chemotherapy preoperatively, an alternative that offers advantages compared to concomitant chemoradiotherapy with or without postoperative chemotherapy. In a multi-centre setting this regimen is compared to current standard with the aim of improving survival for patients with locally advanced rectal cancer.ClinicalTrials.gov NCT01558921.

Project description:INTRODUCTION:Preoperative radiotherapy followed by total mesorectal excision with adjuvant chemotherapy has been recommended as the preferred treatment method for locally advanced rectal cancer (LARC). Similar rates of local control, survival and toxicity were observed in preoperative long-course chemoradiotherapy (LCRT) (45-50.4 Gy in 25-28 fractions) and in short-course radiotherapy (SCRT) with 25 Gy over five fractions. Both regimens lower the local recurrence rates compared with that of surgery followed by postoperative radiotherapy. With the simplicity and lower cost of SCRT, a growing number of patients have been receiving SCRT as preoperative radiotherapy. However, the currently established SCRT (25 Gy over five fractions) followed immediately by surgery resulted in poor downstaging and sphincter preservation rate. The pathological complete response (pCR) rate is also markedly lower with SCRT than with LCRT (0.7%vs16%). Several studies recommended SCRT with delayed surgery for more than 4 weeks with expectation of improved pathological outcomes and fewer postoperative complications. While a number of clinical trials demonstrated a persistently better overall local control with SCRT than with LCRT, overall survival advantage has not been observed. Since survival is mainly depended on distant metastases, efforts should be made towards more effective pathological response and systemic treatment. Given the apparent advantages of SCRT, we aimed to establish a dose escalation of SCRT and sequential modified FOLFOX6 (mFOLFOX6) as preoperative therapy for LARC with objectives of achieving an optimal balance of safety, cost effectiveness and clinical outcome, and to support further investigation of this regimen in a phase II/III setting. METHODS:In this phase I study, three dose levels (6Gy×5F, 7Gy×5F, 8Gy×5F to gross tumour volume, while keeping the rest of irradiated volume at 5Gy×5) of SCRT followed by four cycles of mFOLFOX6 chemotherapy as neoadjuvant therapy will be tested by using the traditional 3+3?design. The pCR rate, R0 resection rate, sphincter preservation rate and treatment related toxicity will be assessed. ETHICS AND DISSEMINATION:The study protocol was approved by the Ethics Committee of Fujian Medical University Union Hospital (No. 2017YF020-02) and all participants provided written informed consent. Results from our study will be disseminated in international peer-reviewed journals. All study procedures were developed in order to assure data protection and confidentiality. TRIAL REGISTRATION NUMBER:NCT03466424; Pre-results.

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Project description:BACKGROUND: The additional use of radiotherapy has changed the treatment of locally advanced rectal cancer (LARC) dramatically. But a major achievement has been the development of total mesorectal excision (TME) as a surgical standard and the recognition that the surgeon is the predominant prognostic factor. The benefit of preoperative hypofractionated radiotherapy (SCRT; five fractions each of 5 Gy), initially established by the Swedish Rectal Cancer Trial, has been demonstrated in conjunction with TME by the Dutch Colorectal Cancer Group. The concept of combined neoadjuvant radiochemotherapy (conventional radiation of about 50 Gy with chemotherapy) has not been compared over surgery alone with TME. However, the German Rectal Cancer Study Group recently demonstrated that preoperative radiochemotherapy (RCT) was better than postoperative radiochemotherapy in terms of local control. METHODS AND DESIGN: Patients with histological proven rectal cancer staged T2N+ or T3 are randomized to receive either SCRT (25 Gy in five fractions of 5 Gy) plus TME-surgery within 5 days or RCT (50.4 Gy in 28 fractions of 1.8 Gy, continuous infusion 5-fluorouracil) plus TME-surgery 4-6 weeks later. All patients receive adjuvant chemotherapy (12 weeks continuous infusional 5-FU) and are followed up for 5 years. TME-quality is independently documented by the surgeon and the pathologist. Hypothesis of the study is that RCT is superior to SCRT in terms of local recurrence after five years. Secondary endpoints are overall survival, disease-free survival, complete resection rate (R0 resection), rate of sphincter saving resection, acute and late toxicity (radiation related side effects), and quality of life (including long term bowel function). DISCUSSION: Similar long-term survival, local control and late morbidity have been reported for both concepts of preoperative therapy in non-comparative studies. In addition to other ongoing (and recently published) comparative trials we include a larger number of patients for adequate power, apply quality-controlled TME and try to avoid the adjuvant treatment bias by mandatory adjuvant chemotherapy in both groups. Further more, stratification of the initially planned surgical procedure and sphincter-preservation will generate valid evidence whether RCT will allow a less aggressive (sphincter saving) surgical approach.