Chemotherapy or No Chemotherapy in Clear Margins after Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: CHRONICLE. A Randomised Phase III Trial of Control vs. Capecitabine plus Oxaliplatin

Role of radiotherapy for resectable rectal cancer

SUMMARY The role of radiation therapy in the treatment of resectable rectal cancer is better defined than at any point in history; however, as technology improves, increasing treatment options can lead to better patient care when used appropriately with adequate training. Understanding the risk factors for local recurrence can assist in delivering individualized treatment options. Technological improvements such as intensity-modulated radiation therapy have the potential to decrease toxicity, but without adequate training, highly conformal treatment can result in undertreating or missing critical areas. This review will provide an overview of treatment and standard treatment options for resectable rectal cancer, as well as an update on the state of radiation therapy as it relates to rectal cancer and the use of intensity-modulated radiation therapy.

High-dose radiotherapy (60 Gy) with oral UFT/folinic acid and escalating doses of oxaliplatin in patients with non-resectable locally advanced rectal cancer (LARC): a phase I trial

BACKGROUND

Consensus is that patients with locally advanced rectal cancer (LARC) should receive long-term chemoradiotherapy (CRT) before surgery. With the intent to offer the patients intensified concomitant chemotherapy (CT) to improve outcome and to assess tolerability and toxicity of oxaliplatin (Ox) a phase I trial of high dose pelvic radiotherapy (RT), fixed dose of oral UFT/l-leucovorin and increasing doses of weekly Ox were performed.

METHODS

Pelvic RT with 48.6 Gy/27 fractions was given to the primary tumour and the regional lymph nodes and a concurrent boost of 5.4 Gy/27 fractions with a final boost of 6 Gy/3 fractions was given to the gross tumour volume (GTV) (60 Gy/30 fractions). Concurrent with RT patients received a daily dose of UFT 300 mg/m(2) plus fixed dose l-leucovorin 22.5 mg 5/7 days and increasing weekly doses of Ox with 10 mg/m(2)/week from a start dose of 30 mg/m(2)/week to a maximum of 60 mg/m(2)/week. In addition, before and after CRT the patients received one course of TEGAFOX (UFT 300 mg/m(2) with l/leucovorin 22.5 mg Days 1-14 and Ox 130 mg/m(2) given on Day 1). Surgery was planned at least six weeks after the completion of the CRT.

RESULTS

From May 2005 to March 2009, 18 patients with LARC (16 primary, two recurrent) were included in this phase I trial. Toxicity was low with only 5-17% grade 3-4 toxicity. Fifteen patients (83%) were operated (14 R0 resection and 1 R1 resection) after completion of CRT. Five (33%) patients had a pathological complete response (ypCR). When ypCR was combined with yp few residual cells, the rate was 60%. Thirteen patients are still alive December 2011.

CONCLUSION

Preoperative high-dose RT and concomitant UFT with increasing doses of Ox up to 60 mg/m(2)/week was feasible with low toxicity, high ypCR rates and promising OS in patients with non-resectable LARC.

Locally advanced rectal cancer: a comparison of management strategies

Traditionally, there has been a high local recurrence rate in rectal cancer and 10-40% of patients require a permanent stoma. Both short-course preoperative radiotherapy (SCPRT) and long-course preoperative chemoradiation (CRT) are used to reduce the risk of local recurrence and enable a curative resection. Total mesorectal excision has reduced the rate of local recurrence (even without radiotherapy) to below 10%, but has highlighted a high risk of metastatic disease in 30-40% of patients. Current trials suggest that in resectable cancers, where the preoperative magnetic resonance imaging (MRI) suggests the circumferential resection margin (CRM) is not potentially involved, then SCPRT and CRT are equivalent in terms of outcomes such as local recurrence, disease-free survival (DFS) and overall survival (OS). For patients with more advanced disease, where the CRM is breached or threatened according to the MRI, the integration of more active chemotherapy and biological agents into chemoradiation is an attractive strategy because of the high risk of metastases. However, in none of the trials published in the last decade has chemoradiation impacted on DFS or OS. We examine the strategies of neoadjuvant, concurrent, consolidation (after chemoradiation and before surgery) and postoperative adjuvant chemotherapy with cytotoxic agents, and the integration of biological agents for future potential strategies of treatment. We also compare the trials and compare the different strategies of long-course preoperative radiotherapy and SCPRT; the intensification of preoperative radiation and chemoradiation with dose escalation of external beam radiotherapy, using brachytherapy, intra-operative radiotherapy, hyperfractionation, and various available techniques such as intensity-modulated radiotherapy. We recommend examining dose escalation of radiotherapy to the primary tumour where MRI predicts a threatened CRM. Of the potential treatment strategies involving cytotoxic agents, such as neoadjuvant, concurrent, consolidation and postoperative adjuvant chemotherapy, the most promising would appear to be consolidation chemotherapy following chemoradiation in locally advanced disease, and neoadjuvant chemotherapy in MRI-selected patients who do not require radiation. Improvement in the quality of surgery is also an important future goal.

Radiation, chemotherapy and biological therapy in the curative treatment of locally advanced rectal cancer

OBJECTIVE

To review the published evidence relating to the use of radiotherapy (RT), chemotherapy and biological therapy as adjuncts to surgery in the curative treatment of rectal cancer.

METHODS

Searches were carried out of the MEDLINE and CANCERLIT databases together with conference abstracts from key meetings including the American Society of Clinical Oncology Annual Meeting and Gastrointestinal Cancers Symposium and the ECCO/ESMO Multidisciplinary Congress.

RESULTS

RT reduces local pelvic recurrence when used as an adjunct to surgery, even when this is performed optimally by total mesorectal excision (TME). RT is usually given as short-course preoperative radiotherapy (SCPRT) followed by immediate surgery which produces no or very little downstaging or long-course concurrent chemoradiation (CRT) followed by a 6-8 week gap prior to surgery which produces significant downstaging. The prognostic importance of achieving a clear histological circumferential resection margin is now well recognised and pathological assessment of the quality of surgery can predict long-term outcomes. Internationally there is considerable heterogeneity in the staging modalities and criteria used in deciding which approach might be used, in the reporting of histological results and in RT parameters (time/dose/fractionation/volume). Attempts to increase the potency of CRT have included the addition of concurrent chemotherapeutic and biological agents to the standard fluoropyrimidine although there is little randomised data and none with regard to long-term survival outcomes. Neither SCPRT nor downstaging CRT have been shown to reduce the rate of subsequent distant metastatic relapse which remains a significant clinical problem. The potential additional benefit of neoadjuvant or adjuvant chemotherapy in addition to SCPRT or long-course CRT remains ill-defined. Late morbidity can include bowel and sexual dysfunction, pelvic fractures and second malignancies with considerably more being known in relation to SCPRT than long-course CRT.

CONCLUSIONS

Improvements in imaging, pathology and surgical technique combined with multimodality treatment using RT and chemotherapy are leading to continuing improvements in the long term outcome for patients with rectal cancer although much remains to be learnt regarding the optimum strategy for use of these in different clinical contexts and their relationship to long-term morbidity.

Circumferential resection margin as a prognostic factor in rectal cancer

BACKGROUND

This study examined the prognostic impact of the circumferential resection margin (CRM) in patients with rectal cancer treated by total mesorectal excision (TME) with or without radiotherapy.

METHODS

A national population-based rectal cancer registry included 3196 patients with known CRM status between 1993 and 2004. Some 90.5 per cent of the patients had surgery alone and 9.5 per cent had preoperative radiotherapy. Patients who did not have TME, those in whom the CRM was not measured, patients with intraoperative bowel or tumour perforation and those who received postoperative radiotherapy were excluded.

RESULTS

Five-year local recurrence, distant metastasis and overall survival rates were 23.7, 43.9 and 44.5 per cent respectively for patients with a CRM of 0-2 mm, compared with 8.9, 21.7 and 66.7 per cent respectively for those with wider margins. A CRM of 2 mm or less had an impact on the prognosis of T2 and T3 tumours located 6-15 cm above the anal verge, but not on lower tumours. CRM also had a prognostic impact on the three endpoints in patients who received preoperative radiotherapy, but with less precision.

CONCLUSION

A CRM of 2 mm or less confers a poorer prognosis and patients should be considered for neoadjuvant treatment.

Staging, prognostic factors, and therapy of localized rectal cancer

Many recent developments have taken place in the management of rectal cancer. Appropriate staging plays an increasingly important role in rectal cancer, because many treatment decisions must be based on preoperative staging. Also critical is the role of prognostic factors such as the pathologic T (tumor) and N (nodal) classification, circumferential resection margin, and response to preoperative therapy. For stage II and III rectal cancer, preoperative chemo-radiation and radiotherapy have been accepted widely as a standard of care. The German Rectal Cancer Trial demonstrated the superiority of preoperative chemoradiation over postoperative chemoradiation, whereas the trials from the European Organisation for Research and Treatment of Cancer and Fédération Francophone de Cancérologie Digestive showed the benefits of preoperative chemoradiation over preoperative long-course radiotherapy. Multiple randomized trials also have established the role of hypofractionated or short-course radiotherapy. For stage I rectal cancer, local excision is being used increasingly, but recent studies show the need for caution with the use of this technique. This article reviews recent studies on staging, prognostic factors, and therapy of localized rectal cancer.