Randomized phase II study of neoadjuvant combined-modality chemoradiation for distal rectal cancer: Radiation Therapy Oncology Group Trial 0012

Neoadjuvant treatment in rectal cancer: actual status

Neoadjuvant (preoperative) concomitant chemoradiotherapy (CRT) has become a standard treatment of locally advanced rectal adenocarcinomas. The clinical stages II (cT3-4, N0, M0) and III (cT1-4, N+, M0) according to International Union Against Cancer (IUCC) are concerned. It can reduce tumor volume and subsequently lead to an increase in complete resections (R0 resections), shows less toxicity, and improves local control rate. The aim of this review is to summarize actual approaches, main problems, and discrepancies in the treatment of locally advanced rectal adenocarcinomas.

Neoadjuvant capecitabine, radiotherapy, and bevacizumab (CRAB) in locally advanced rectal cancer: results of an open-label phase II study

Background

Preoperative capecitabine-based chemoradiation is a standard treatment for locally advanced rectal cancer (LARC). Here, we explored the safety and efficacy of the addition of bevacizumab to capecitabine and concurrent radiotherapy for LARC.

Methods

Patients with MRI-confirmed stage II/III rectal cancer received bevacizumab 5 mg/kg i.v. 2 weeks prior to neoadjuvant chemoradiotherapy followed by bevacizumab 5 mg/kg on Days 1, 15 and 29, capecitabine 825 mg/m² twice daily on Days 1-38, and concurrent radiotherapy 50.4 Gy (1.8 Gy/day, 5 days/week for 5 weeks + three 1.8 Gy/day), starting on Day 1. Total mesorectal excision was scheduled 6-8 weeks after completion of chemoradiotherapy. Tumour regression grades (TRG) were evaluated on surgical specimens according to Dworak. The primary endpoint was pathological complete response (pCR).

Results

61 patients were enrolled (median age 60 years [range 31-80], 64% male). Twelve patients (19.7%) had T3N0 tumours, 1 patient T2N1, 19 patients (31.1%) T3N1, 2 patients (3.3%) T2N2, 22 patients (36.1%) T3N2 and 5 patients (8.2%) T4N2. Median tumour distance from the anal verge was 6 cm (range 0-11). Grade 3 adverse events included dermatitis (n = 6, 9.8%), proteinuria (n = 4, 6.5%) and leucocytopenia (n = 3, 4.9%). Radical resection was achieved in 57 patients (95%), and 42 patients (70%) underwent sphincter-preserving surgery. TRG 4 (pCR) was recorded in 8 patients (13.3%) and TRG 3 in 9 patients (15.0%). T-, N- and overall downstaging rates were 45.2%, 73.8%, and 73.8%, respectively.

Conclusions

This study demonstrates the feasibility of preoperative chemoradiotherapy with bevacizumab and capecitabine. The observed adverse events of neoadjuvant treatment are comparable with those previously reported, but the pCR rate was lower.

Radiation Therapy Oncology Group 0247: a randomized Phase II study of neoadjuvant capecitabine and irinotecan or capecitabine and oxaliplatin with concurrent radiotherapy for patients with locally advanced rectal cancer

PURPOSE

To evaluate the rate of pathologic complete response (pCR) and the toxicity of two neoadjuvant chemoradiotherapy (chemoRT) regimens for Stage T3-T4 rectal cancer in a randomized Phase II study.

METHODS AND MATERIALS

Patients with Stage T3 or T4 rectal cancer of <12 cm from the anal verge were randomized to preoperative RT (50.4 Gy in 1.8-Gy fractions) with concurrent capecitabine (1,200 mg/m(2)/d Mondays through Friday) and irinotecan (50 mg/m(2) weekly in four doses) (Arm 1) or concurrent capecitabine (1,650 mg/m(2)/d Monday through Friday) and oxaliplatin (50 mg/m(2) weekly in five doses) (Arm 2). Surgery was performed 4-8 weeks after chemoRT, and adjuvant chemotherapy 4-6 weeks after surgery. The primary endpoint was the pCR rate, requiring 48 evaluable patients per arm.

RESULTS

A total of 146 patients were enrolled. The protocol chemotherapy was modified because of excessive gastrointestinal toxicity after treatment of 35 patients; 96 were assessed for the primary endpoint-the final regimen described above. The patient characteristics were similar for both arms. After chemoRT, the rate of tumor downstaging was 52% and 60% and the rate of nodal downstaging (excluding N0 patients) was 46% and 40%, for Arms 1 and 2, respectively. The pCR rate for Arm 1 was 10% and for Arm 2 was 21%. For Arm 1 and 2, the preoperative chemoRT rate of Grade 3-4 hematologic toxicity was 9% and 4% and the rate of Grade 3-4 nonhematologic toxicity was 26% and 27%, respectively.

CONCLUSIONS

Preoperative chemoRT with capecitabine plus oxaliplatin for distal rectal cancer has significant clinical activity (10 of 48 pCRs) and acceptable toxicity. This regimen is currently being evaluated in a Phase III randomized trial (National Surgical Adjuvant Breast and Bowel Project R04).

Nomograms for predicting local recurrence, distant metastases, and overall survival for patients with locally advanced rectal cancer on the basis of European randomized clinical trials

PURPOSE

The purpose of this study was to develop accurate models and nomograms to predict local recurrence, distant metastases, and survival for patients with locally advanced rectal cancer treated with long-course chemoradiotherapy (CRT) followed by surgery and to allow for a selection of patients who may benefit most from postoperative adjuvant chemotherapy and close follow-up.

PATIENTS AND METHODS

All data (N = 2,795) from five major European clinical trials for rectal cancer were pooled and used to perform an extensive survival analysis and to develop multivariate nomograms based on Cox regression. Data from one trial was used as an external validation set. The variables used in the analysis were sex, age, clinical tumor stage stage, tumor location, radiotherapy dose, concurrent and adjuvant chemotherapy, surgery procedure, and pTNM stage. Model performance was evaluated by the concordance index (c-index). Risk group stratification was proposed for the nomograms.

RESULTS

The nomograms are able to predict events with a c-index for external validation of local recurrence (LR; 0.68), distant metastases (DM; 0.73), and overall survival (OS; 0.70). Pathologic staging is essential for accurate prediction of long-term outcome. Both preoperative CRT and adjuvant chemotherapy have an added value when predicting LR, DM, and OS rates. The stratification in risk groups allows significant distinction between Kaplan-Meier curves for outcome.

CONCLUSION

The easy-to-use nomograms can predict LR, DM, and OS over a 5-year period after surgery. They may be used as decision support tools in future trials by using the three defined risk groups to select patients for postoperative chemotherapy and close follow-up (http://www.predictcancer.org).

Prognostic significance of adverse events associated with preoperative radiotherapy for rectal cancer

PURPOSE

Adverse events may occur in patients receiving preoperative radiotherapy (PRT) for rectal cancers. The aim of this study is to clarify the clinical and pathological features of the patients with PRT-related adverse events, and the significance of the adverse events on the clinical outcome.

METHODS

Seventy-five patients with T3 or T4 low rectal cancers curatively resected following PRT were studied. Thirty-one patients received radiotherapy, and 44 patients received chemoradiotherapy with tegafur-uracil and leucovorin. The total radiation dose was 50-50.4 Gy given in 25-28 fractions and the operation was performed 4-8 weeks after PRT. PRT-related adverse events were graded in accordance with the Common Terminology Criteria for Adverse Events v3.0.

RESULTS

The most frequent adverse events were leukocytopenia and diarrhea, observed in 12% and 24% of patients, respectively. The majority of the leukocytopenia and diarrhea was grade 1-2 toxicity. Women experienced leukocytopenia more frequently than men (28% vs. 7%, p = 0.0317); however, no other predisposing factor for adverse events was recognized. Patients with leukocytopenia or diarrhea showed a better 5-year relapse-free survival rate than those without (94 ± 5% vs. 49 ± 9%, p = 0.00054), and the presence of these adverse events was an independent prognostic factor in a multivariate analysis.

CONCLUSIONS

The presence of leukocytopenia or diarrhea was an independent predictor of a fair prognosis after curative operation following PRT, and thus these adverse events seem not to discourage oncologists and patients from considering PRT for rectal cancers.

Predictive factors of pathologic complete response after neoadjuvant chemoradiation for rectal cancer

OBJECTIVE

This study evaluates factors associated with a pathologic complete response (pCR) after neoadjuvant chemoradiation for rectal cancer.

SUMMARY BACKGROUND DATA

Approximately 20% of rectal cancer patients undergoing neoadjuvant chemoradiation achieve pCR, which has been associated with decreased local recurrence and improved recurrence-free survival. Means of predicting pCR remain incompletely defined.

METHODS

A total of 306 consecutive patients with stage II or stage III rectal cancer who underwent neoadjuvant chemoradiation then surgery between 1997 and 2007 were identified from a single-institution. Sixty-four patients with concurrent inflammatory bowel disease, hereditary colorectal cancer, other malignancy, urgent surgery, incomplete chemoradiation, or insufficient data were excluded. All patients received neoadjuvant 5-FU-based chemotherapy and external beam radiation. Histologic response was categorized as pCR or not-pCR, which defined the 2 study cohorts. Variables were analyzed by univariate and multivariate analysis with pCR as the dependent variable. Fisher exact test, chi2, Wilcoxon rank-sum, and logistic regression were used for analysis. P < 0.05 was considered statistically significant.

RESULTS

Of the total patients, 242 were studied, including 58 (24%) that achieved pCR. The 2 groups were statistically similar in terms of age, gender, body mass index, tumor differentiation, radiation dose, and pretreatment stage. On multivariate analysis, an interval ≥ 8 weeks between treatment completion and surgical resection was significantly associated with a higher rate of pCR, which correlated with decreased local recurrence and improved overall survival.

CONCLUSION

Despite traditional beliefs that certain patient and tumor factors influence pCR, an extended interval between completion of neoadjuvant therapy and surgery was the single most important determinant in achieving a pCR.

Primary tumor response to preoperative chemoradiation with or without oxaliplatin in locally advanced rectal cancer: pathologic results of the STAR-01 randomized phase III trial

PURPOSE

To investigate oxaliplatin combined with fluorouracil-based chemoradiotherapy as preoperative treatment for locally advanced rectal cancer.

PATIENTS AND METHODS

Seven hundred forty-seven patients with resectable, locally advanced (cT3-4 and/or cN1-2) adenocarcinoma of the mid-low rectum were randomly assigned to receive pelvic radiation (50.4 Gy in 28 daily fractions) and concomitant infused fluorouracil (225 mg/m(2)/d) either alone (arm A, n = 379) or combined with oxaliplatin (60 mg/m(2) weekly × 6; arm B, n = 368). Overall survival is the primary end point. A protocol-planned analysis of response to preoperative treatment is reported here.

RESULTS

Grade 3 to 4 adverse events during preoperative treatment were more frequent with oxaliplatin plus fluorouracil and radiation than with radiation and fluorouracil alone (24% v 8% of treated patients; P < .001). In arm B, 83% of the patients treated with oxaliplatin had five or more weekly administrations. Ninety-one percent, compared with 97% in the control arm, received ≥ 45 Gy (P < .001). Ninety-six percent versus 95% of patients underwent surgery with similar rates of abdominoperineal resections (20% v 18%, arm A v arm B). The rate of pathologic complete responses was 16% in both arms (odds ratio = 0.98; 95% CI, 0.66 to 1.44; P = .904). Twenty-six percent versus 29% of patients had pathologically positive lymph nodes (arm A v arm B; P = .447), 46% versus 44% had tumor infiltration beyond the muscularis propria (P = .701), and 7% versus 4% had positive circumferential resection margins (P = .239). Intra-abdominal metastases were found at surgery in 2.9% versus 0.5% of patients (arm A v arm B; P = .014).

CONCLUSION

Adding oxaliplatin to fluorouracil-based preoperative chemoradiotherapy significantly increases toxicity without affecting primary tumor response. Longer follow-up is needed to assess the impact on efficacy end points.

Addition of bevacizumab to XELOX induction therapy plus concomitant capecitabine-based chemoradiotherapy in magnetic resonance imaging-defined poor-prognosis locally advanced rectal cancer: the AVACROSS study

BACKGROUND

Concomitant chemoradiotherapy followed by total mesorectal excision is standard treatment for locally advanced rectal cancer. This approach, however, focuses on local disease control and delays systemic treatment. Induction chemotherapy has the advantage of earlier administration of systemic therapy and may improve distant control. The objective of the current study was to assess the efficacy and toxicity of adding bevacizumab to induction chemotherapy followed by preoperative bevacizumab-based chemoradiotherapy in patients with locally advanced rectal cancer.

PATIENTS AND METHODS

Eligible patients had high-risk rectal adenocarcinoma defined by magnetic resonance imaging criteria. Treatment consisted of four 21-day cycles of bevacizumab (7.5 mg/kg) and XELOX (capecitabine plus oxaliplatin), followed by concomitant radiotherapy (50.4 Gy) plus bevacizumab (5 mg/kg every 2 weeks) and capecitabine (825 mg/m2 twice daily on days 1-15). Surgery was scheduled for 6-8 weeks after chemoradiotherapy. The primary endpoint was pathologic complete response (pCR).

RESULTS

Between July 2007 and July 2008, 47 patients were recruited. Among 45 patients who underwent surgery, pCR was achieved in 16 patients (36%; 95% confidence interval: 22.29%-51.27%), and an additional 17 patients (38%) had Dworak tumor regression grade 3. R0 resection was performed in 44 patients (98%). Most grade 3/4 adverse events occurred during the induction phase and included diarrhea (11%), asthenia (4%), neutropenia (6%), and thrombocytopenia (4%). Eleven patients (24%) required surgical reintervention.

CONCLUSIONS

Addition of bevacizumab to induction chemotherapy and chemoradiotherapy is feasible, with impressive activity and manageable toxicity. However, caution is recommended regarding surgical complications.

Can we increase the chance of sphincter saving surgery in rectal cancer with neoadjuvant treatments: lessons from a systematic review of recent randomized trials

PURPOSE

A common hypothesis is that neo-adjuvant treatment in rectal cancer, is able to increase sphincter saving surgery. This review studies data relevant to this question.

STUDY SELECTION

A total of 17 randomized trials were analysed.

RESULTS

Since 1976, the rate of sphincter saving surgery increased from 20% to 75%. In none of the 17 trials it was possible to demonstrate a significant benefit of the neo-adjuvant regimens on the rate of sphincter saving surgery. There was a reduction in the risk of 5-year local recurrence partly due to these neo-adjuvant treatments. These neo-adjuvant regimens had no significant impact on the overall 5-year survival.

CONCLUSIONS

None of the neo-adjuvant treatments tested was able to demonstrate an increase in the rate of sphincter saving surgery. The improvement in conservative surgery is mainly due to technical changes in surgery. Organ preservation after complete clinical response appears as an interesting hypothesis to test.

Thymidylate synthase genotype-directed neoadjuvant chemoradiation for patients with rectal adenocarcinoma

PURPOSE

Downstaging (DS) of rectal cancers is achieved in approximately 45% of patients with neoadjuvant fluorouracil (FU) -based chemoradiotherapy (CRT). Polymorphisms in the thymidylate synthase gene (TYMS) had previously defined two risk groups associated with disparate tumor DS rates (60% v 22%). We conducted a prospective single-institution phase II study using TYMS genotyping to direct neoadjuvant CRT for patients with rectal cancer.

PATIENTS AND METHODS

Patients with T3/T4, N0-2, M0-1 rectal adenocarcinoma were evaluated for germline TYMS genotyping. Patients with TYMS *2/*2, *2/*3, or *2/*4 (good risk) were treated with standard chemoradiotherapy using infusional FU at 225 mg/m²/d. Patients with TYMS *3/*3 or *3/*4 (poor risk) were treated with FU/RT plus weekly intravenous irinotecan at 50 mg/m². The primary end point was pathologic DS. Secondary end points included complete tumor response (ypT0), toxicity, recurrence rates, and overall survival.

RESULTS

Overall, 135 patients were enrolled, of whom 27.4% (37 of 135) were considered poor risk. The prespecified statistical goals were achieved, with DS and ypT0 rates reaching 64.4% and 20% for good-risk and 64.5% and 42% for poor-risk patients, respectively.

CONCLUSION

To our knowledge, this is the first study to prospectively use TYMS genotyping to direct neoadjuvant CRT in patients with rectal cancer. High rates of DS and ypT0 were achieved among both risk groups when personalized treatment was based on TYMS genotype. These results are encouraging, and further evaluation of this genotype-based strategy using a randomized study design for locally advanced rectal cancer is warranted.

Neoadjuvant therapy for rectal cancer: the impact of longer interval between chemoradiation and surgery

PURPOSE

The aim of this study was to determine the effect of a longer interval between neoadjuvant chemoradiation and surgery on perioperative morbidity and oncologic outcomes.

METHODS

A colorectal cancer database was queried for clinical stage II and III rectal cancer patients undergoing neoadjuvant chemoradiation followed by proctectomy between 1997 and 2007. The neoadjuvant regimen consisted of long course external beam radiation and 5-fluorouracil chemotherapy. Patients with inflammatory bowel disease, hereditary cancer, extracolonic malignancy, urgent surgery, or non-validated treatment dates were excluded. Patients were divided into two groups according to the interval between chemoradiation and surgery (<8 and ≥ 8 weeks). Perioperative complications and oncologic outcomes were compared.

RESULTS

One hundred seventy-seven patients were included. Groups were comparable with respect to demographics, tumor, and treatment characteristics. Perioperative complications were not affected by the interval between chemoradiation and surgery. Patients undergoing surgery ≥ 8 weeks after chemoradiation experienced a significant improvement in pathologic complete response rate (30.8% vs. 16.5%, p = 0.03) and had decreased 3-year local recurrence rate (1.2% vs. 10.5%, p = 0.04). A Cox regression analysis was performed to assess the compounding effect of a complete pathologic response on oncologic outcome. A longer interval correlated with less local recurrence, although statistical significance was not reached (p = 0.07).

CONCLUSION

An interval between chemoradiation and surgery ≥ 8 weeks is safe and is associated with a higher rate of pathologic complete response and decreased local recurrence.

Chemoradiation for rectal cancer: rationale, approaches, and controversies

The standard adjuvant treatment of cT3 and/or N+ rectal cancer is preoperative chemoradiation. However, there are many controversies regarding this approach. These controversies include the role of short course radiation, whether postoperative adjuvant chemotherapy is necessary for all patients, and if the type of surgery following chemoradiation should be based on the response rate. More accurate imaging techniques and/or molecular markers may help identify patients with positive pelvic nodes to reduce the chance of overtreatment with preoperative therapy. Will more effective systemic agents both improve the results of radiation, as well as modify the need for pelvic radiation? These questions and others remain active areas of clinical investigation.

Evidence and research perspectives for surgeons in the European Rectal Cancer Consensus Conference (EURECA-CC2)

PURPOSE

Although surgery remains the most important treatment of rectal cancer, the management of this disease has evolved to become more multidisciplinary to offer the best clinical outcome. The International Conference on Multidisciplinary Rectal Cancer Treatment: Looking for an European Consensus' (EURECA-CC2) had the duty to identify the degree of consensus that could be achieved across a wide range of topics relating to the management of rectal cancer helping shape future programs, investigational protocols and guidelines for staging and treatment throughout Europe.

MATERIALS AND METHODS

Consensus was achieved using the Delphi method. Eight chapters were identified: epidemiology, diagnostics, pathology, surgery, radiotherapy and chemotherapy, treatment toxicity and quality of life, follow-up, and research questions. Each chapter was subdivided by topic, and a series of statements were developed. Each committee member commented and voted, sentence by sentence three times. Sentences which did not reach agreement after voting round #2 were openly debated during the Conference in Perugia (Italy) December 2008. The Executive Committee scored percentage consensus based on three categories: "large consensus", "moderate consensus", "minimum consensus".

RESULTS

The total number of the voted sentences was 207. Of the 207, 86% achieved large consensus, 13% achieved moderate consensus, and only 3 (1%) resulted in minimum consensus. No statement was disagreed by more than 50% of members. All chapters were voted on by at least 75% of the members, and the majority was voted on by 85%.

CONCLUSIONS

This Consensus Conference represents an expertise opinion process that may help shape future programs, investigational protocols, and guidelines for staging and treatment of rectal cancer throughout Europe. In spite of substantial progress, many research challenges remain.

Rectal cancer radiotherapy: towards European consensus

BACKGROUND AND PURPOSE

During the first decade of the 21st century several important European randomized studies in rectal cancer have been published. In order to help shape clinical practice based on best scientific evidence, the International Conference on 'Multidisciplinary Rectal Cancer Treatment: Looking for an European Consensus' (EURECA-CC2) was organized. This article summarizes the consensus about imaging and radiotherapy of rectal cancer and gives an update until May 2010.

METHODS

Consensus was achieved using the Delphi method. Eight chapters were identified: epidemiology, diagnostics, pathology, surgery, radiotherapy and chemotherapy, treatment toxicity and quality of life, follow-up, and research questions. Each chapter was subdivided by topic, and a series of statements were developed. Each committee member commented and voted, sentence by sentence three times. Sentences which did not reach agreement after voting round # 2 were openly debated during the Conference in Perugia (Italy) December 2008. The Executive Committee scored percentage consensus based on three categories: "large consensus", "moderate consensus", "minimum consensus".

RESULTS

The total number of the voted sentences was 207. Of the 207, 86% achieved large consensus, 13% achieved moderate consensus, and only three (1%) resulted in minimum consensus. No statement was disagreed by more than 50% of members. All chapters were voted on by at least 75% of the members, and the majority was voted on by >85%. Considerable progress has been made in staging and treatment, including radiation treatment of rectal cancer.

CONCLUSIONS

This Consensus Conference represents an expertise opinion process that may help shape future programs, investigational protocols, and guidelines for staging and treatment of rectal cancer throughout Europe. In spite of substantial progress, many research challenges remain.

Neoadjuvant bevacizumab, oxaliplatin, 5-fluorouracil, and radiation for rectal cancer

PURPOSE

To evaluate the feasibility and pathologic complete response rate of induction bevacizumab + modified infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) 6 regimen followed by concurrent bevacizumab, oxaliplatin, continuous infusion 5-fluorouracil (5-FU), and radiation for patients with rectal cancer.

METHODS AND MATERIALS

Eligible patients received 1 month of induction bevacizumab and mFOLFOX6. Patients then received 50.4 Gy of radiation and concurrent bevacizumab (5 mg/kg on Days 1, 15, and 29), oxaliplatin (50 mg/m(2)/week for 6 weeks), and continuous infusion 5-FU (200 mg/m(2)/day). Because of gastrointestinal toxicity, the oxaliplatin dose was reduced to 40 mg/m(2)/week. Resection was performed 4-8 weeks after the completion of chemoradiation.

RESULTS

The trial was terminated early because of toxicity after 26 eligible patients were treated. Only 1 patient had significant toxicity (arrhythmia) during induction treatment and was removed from the study. During chemoradiation, Grade 3/4 toxicity was experienced by 19 of 25 patients (76%). The most common Grade 3/4 toxicities were diarrhea, neutropenia, and pain. Five of 25 patients (20%) had a complete pathologic response. Nine of 25 patients (36%) developed postoperative complications including infection (n = 4), delayed healing (n = 3), leak/abscess (n = 2), sterile fluid collection (n = 2), ischemic colonic reservoir (n = 1), and fistula (n = 1).

CONCLUSIONS

Concurrent oxaliplatin, bevacizumab, continuous infusion 5-FU, and radiation causes significant gastrointestinal toxicity. The pathologic complete response rate of this regimen was similar to other fluorouracil chemoradiation regimens. The high incidence of postoperative wound complications is concerning and consistent with other reports utilizing bevacizumab with chemoradiation before major surgical resections.

Combined modality therapy for rectal cancer

The standard adjuvant treatment for cT3 and/or N+ rectal cancer is preoperative chemoradiation. However, there are many controversies regarding this approach. These include the role of short course radiation, whether postoperative adjuvant chemotherapy necessary for all patients and whether the type of surgery after chemoradiation should be based on the response rate. More accurate imaging techniques and/or molecular markers may help identify patients with positive pelvic nodes to reduce the chance of overtreatment with preoperative therapy. Will more effective systemic agents both improve the results of radiation as well as modify the need for pelvic radiation? These questions and others remain active areas of clinical investigation.

Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data

BACKGROUND

Locally advanced rectal cancer is usually treated with preoperative chemoradiation. After chemoradiation and surgery, 15-27% of the patients have no residual viable tumour at pathological examination, a pathological complete response (pCR). This study established whether patients with pCR have better long-term outcome than do those without pCR.

METHODS

In PubMed, Medline, and Embase we identified 27 articles, based on 17 different datasets, for long-term outcome of patients with and without pCR. 14 investigators agreed to provide individual patient data. All patients underwent chemoradiation and total mesorectal excision. Primary outcome was 5-year disease-free survival. Kaplan-Meier survival functions were computed and hazard ratios (HRs) calculated, with the Cox proportional hazards model. Subgroup analyses were done to test for effect modification by other predicting factors. Interstudy heterogeneity was assessed for disease-free survival and overall survival with forest plots and the Q test.

FINDINGS

484 of 3105 included patients had a pCR. Median follow-up for all patients was 48 months (range 0-277). 5-year crude disease-free survival was 83.3% (95% CI 78.8-87.0) for patients with pCR (61/419 patients had disease recurrence) and 65.6% (63.6-68.0) for those without pCR (747/2263; HR 0.44, 95% CI 0.34-0.57; p<0.0001). The Q test and forest plots did not suggest significant interstudy variation. The adjusted HR for pCR for failure was 0.54 (95% CI 0.40-0.73), indicating that patients with pCR had a significantly increased probability of disease-free survival. The adjusted HR for disease-free survival for administration of adjuvant chemotherapy was 0.91 (95% CI 0.73-1.12). The effect of pCR on disease-free survival was not modified by other prognostic factors.

INTERPRETATION

Patients with pCR after chemoradiation have better long-term outcome than do those without pCR. pCR might be indicative of a prognostically favourable biological tumour profile with less propensity for local or distant recurrence and improved survival.

FUNDING

None.

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.

Preoperative chemoradiotherapy for rectal cancer: a comparison between intravenous 5-fluorouracil and oral capecitabine

INTRODUCTION

Capecitabine provides an attractive alternative to intravenous (IV) 5-flourouracil (5-FU) in chemoradiation regimes for rectal cancer by avoiding the need for intravenous access and inpatient stay. We aimed to compare retrospectively the efficacy of concurrent capecitabine with IV 5-FU in preoperative pelvic chemoradiation schedules for rectal cancer in our centre.

METHOD

Patients treated from January 2005 to June 2007 were included. Information was collected on patient characteristics; treatment details; pathological response to treatment; recurrence and survival. All statistical analyses were performed using SPSS V17.

RESULTS

All patients had pelvic radiation. Ninety-nine patients were treated with capecitabine and 97 with 5-FU. The two groups were well matched for age, sex and TNM stage. There were significantly more PS (performance status) 0 patients in the capecitabine group (51%vs 30%) (P = 0.001). Of the 99 patients in the capecitabine group, 91 (92%) were able to undergo surgery with 84 (93%) achieving R0 resection. In the 5-FU group, these proportions were 87 (90%) and 70 (80%). The difference in the rate of R0 resection was statistically significant (P = 0.024). The APR rate was 35% in the capecitabine group compared with 47% in the 5-FU group (P = 0.06). There was no significant difference in pathological complete response (pCR) rates between capecitabine (14%) and 5-FU(12%). A higher pCR rate (30%) was observed in patients who underwent a brachytherapy boost (P = 0.051). There were three local recurrences in the whole patient group, (capecitabine 1; 5-FU 2). Thirty-five patients had distant metastases, 14 in the capecitabine and 21 in the 5-FU group. There was no significant difference in the risk of recurrence between the two groups. Six patients in each group had grade 3 toxicity with diarrhoea being more common with capecitabine.

CONCLUSIONS

Preoperative chemoradiotherapy with capecitabine for rectal cancer is efficacious and comparable to 5-FU (IV). It is more convenient, is well tolerated and avoids the need for inpatient admission.

Management of locally advanced primary and recurrent rectal cancer

Treatment for patients with locally advanced and recurrent rectal cancer differs significantly from patients with rectal cancer restricted to the mesorectum. Adequate preoperative imaging of the pelvis is therefore important to identify those patients who are candidates for multimodality treatment, including preoperative chemoradiation protocols, intraoperative radiotherapy, and extended surgical resections. Much effort should be made to select patients with these advanced tumors for treatment in specialized referral centers. This has been shown to reduce morbidity and mortality and improve long-term survival rates. In this article, we review the best treatment options for patients with locally advanced and recurrent rectal cancer. We also emphasize the necessity of a multidisciplinary team, including a radiologist, radiation oncologist, urologist, surgical oncologist, plastic surgeon, and gynecologist in the diagnosis and treatment of patients with these pelvic tumors.

Medium-term results of neoadjuvant systemic chemotherapy using irinotecan, 5-fluorouracil, and leucovorin in patients with locally advanced rectal cancer

AIMS

The aim of this study was to evaluate the usefulness of neoadjuvant systemic chemotherapy using irinotecan, 5-FU, and leucovorin (LV) for the treatment of locally advanced rectal cancer, which was a powerful ploychemotherapy in those days in Japan.

METHODS

Between 2001 and 2004, 26 patients with T3 or T4 and N0-2 non-metastatic resectable rectal cancer were selectively enrolled in this study. Neoadjuvant chemotherapy consisted of two cycles of irinotecan (80 mg/m²), 5-FU (500 mg/m²), and LV (250 mg/m²) on days 1, 8, and 15 for 4 weeks. Surgical resection was performed in all the patients 2-4 weeks after the completion of chemotherapy.

RESULTS

Overall down-staging was observed in 15 patients. T level and N level down-staging were observed in 12 and 13 patients, respectively. A pathological complete response was observed in one patients. The median follow-up period was 75 months (range, 8-97 months). Recurrences occurred in 5 patients including pelvic relapses in 3 and distant metastases in 2. The 5-year relapse-free and overall survival rates were 74% and 84%, respectively.

CONCLUSIONS

Neoadjuvant systemic chemotherapy comprised of a combination of multi-drugs as irinotecan, 5-FU, and LV may be beneficial to the prognoses of patients with locally advanced rectal cancer.

Preoperative chemoradiation with irinotecan and capecitabine in patients with locally advanced resectable rectal cancer: long-term results of a Phase II study

PURPOSE

Preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer has shown benefit over postoperative CRT; however, a standard CRT regimen has yet to be defined. We performed a prospective concurrent CRT Phase II study with irinotecan and capecitabine in patients with locally advanced rectal cancer to investigate the efficacy and safety of this regimen.

METHODS AND MATERIALS

Patients with locally advanced, nonmetastatic, and mid-to-lower rectal cancer were enrolled. Radiotherapy was delivered in 1.8-Gy daily fractions for a total of 45 Gy in 25 fractions, followed by a coned-down boost of 5.4 Gy in 3 fractions. Concurrent chemotherapy consisted of 40 mg/m(2) of irinotecan per week for 5 consecutive weeks and 1,650 mg/m(2) of capecitabine per day for 5 days per week (weekdays only) from the first day of radiotherapy. Total mesorectal excision was performed within 6 ± 2 weeks. The pathologic responses and survival outcomes were included for the study endpoints.

RESULTS

In total, 48 patients were enrolled; 33 (68.7%) were men and 15 (31.3%) were women, and the median age was 59 years (range, 32-72 years). The pathologic complete response rate was 25.0% (11 of 44; 95% confidence interval, 12.2-37.8) and 8 patients (18.2% [8 of 44]) showed near-total tumor regression. The 5-year disease-free and overall survival rates were 75.0% and 93.6%, respectively. Grade 3 toxicities included leukopenia (3 [6.3%]), neutropenia (1 [2.1%]), infection (1 [2.1%]), alanine aminotransferase elevation (1 [2.1%]), and diarrhea (1 [2.1%]). There was no Grade 4 toxicity or treatment-related death.

CONCLUSIONS

Preoperative CRT with irinotecan and capecitabine with treatment-free weekends showed very mild toxicity profiles and promising results in terms of survival.

Colorectal cancer

Substantial progress has been made in colorectal cancer in the past decade. Screening, used to identify individuals at an early stage, has improved outcome. There is greater understanding of the genetic basis of inherited colorectal cancer and identification of patients at risk. Optimisation of surgery for patients with localised disease has had a major effect on survival at 5 years and 10 years. For rectal cancer, identification of patients at greatest risk of local failure is important in the selection of patients for preoperative chemoradiation, a strategy proven to improve outcomes in these patients. Stringent postoperative follow-up helps the early identification of potentially radically treatable oligometastatic disease and improves long-term survival. Treatment with adjuvant fluoropyrimidine for colon and rectal cancers further improves survival, more so in stage III than in stage II disease, and oxaliplatin-based combination chemotherapy is now routinely used for stage III disease, although efficacy must be carefully balanced against toxicity. In stage II disease, molecular markers such as microsatellite instability might help select patients for treatment. The integration of targeted treatments with conventional cytotoxic drugs has expanded the treatment of metastatic disease resulting in incremental survival gains. However, biomarker development is essential to aid selection of patients likely to respond to therapy, thereby rationalising treatments and improving outcomes.

Preoperative decision making for rectal cancer

BACKGROUND

Rectal cancer treatment has become multimodal as a result of significant advances in imaging, staging, surgery, radiotherapy, and chemotherapy. Multidisciplinary teams can incorporate these developments into tailor-made treatment plans and offer state-of-the-art services for rectal cancer patients.

METHODS

We searched the MEDLINE and PubMed databases using the following keywords: "rectal cancer," "total mesorectal excision," "multidisciplinary treatment/team," "radiotherapy," "chemotherapy," and their combinations. There were no language or publication year restrictions. References in published articles also were reviewed.

RESULTS

Total mesorectal excision surgery, high-resolution pelvic magnetic resonance imaging, preoperative chemoradiotherapy, and pathologic reports according to Quirke protocol are preconditions for the initiation of an effective multidisciplinary team. Common topics for discussion are the status of the circumferential margin, the type of radiotherapy and surgery required, and the chemotherapeutic agent to be used.

CONCLUSIONS

This review focuses on this issue based on two main principles. First, the status of the circumferential margin dictates the use of preoperative chemoradiotherapy. Second, preoperative chemoradiotherapy is superior in terms of free circumferential resection margin rate, local recurrence rate, and toxicity.

Phase II study of preoperative chemoradiotherapy (CRT) with irinotecan plus S-1 in locally advanced rectal cancer

BACKGROUND AND PURPOSE

The aim of this study is to evaluate the efficacy and safety of preoperative radiation therapy combined with S-1 and irinotecan (SI) in LARC.

MATERIALS AND METHODS

Patients were considered LARC if they had a T3/T4 lesion or node positive. Weekly doses of 40 mg/m(2) irinotecan were intravenously administered once per week during weeks 1-5 of radiotherapy. S-1 (70 mg/m(2)) was given from Monday to Friday in all weeks of radiotherapy. 3-D conformal radiotherapy was given at daily fractions of 1.8Gy for 5days for a total dose of 50.4 (45+5.4)Gy. Surgery was performed 4-6 weeks following the completion of chemoradiation.

RESULTS

Between June 2006 and November 2007, 43 pts were enrolled. The stage was: cT3 24 patients, cT4 6 patients; 28 patients were cN+. Forty-one patients completed the chemoradiation and 42 patients underwent operation: a low anterior resection was performed in 36 patients, a total colectomy in 1 patient, and an abdominal perineal resection in 5 patients. T downstaging was observed in 50%; 23 N+ patients became N- (55%). The complete pathological response was observed in 9 patients (21%). The 3-year locoregional failure rate, distant failure rate, disease-free survival, and overall survival were 9.5%, 18.6%, 72.1%, and 94.3%, respectively. Only three patients experienced G3 diarrhea; one had G3 sepsis and two had septic shock. Hematological toxicity (G3-G4) was observed in five patients.

CONCLUSIONS

This study demonstrated the efficacy of preoperative CRT with S-1 and irinotecan with 21% of complete response. However, prompt recognition and management of infection is needed to use it in patients with locally advanced rectal cancer.

Phase II trial of neoadjuvant bevacizumab, capecitabine, and radiotherapy for locally advanced rectal cancer

PURPOSE

We designed this Phase II trial to assess the efficacy and safety of the addition of bevacizumab to concurrent neoadjuvant capecitabine-based chemoradiation in locally advanced rectal cancer.

METHODS

Between April 2004 and December 2007, 25 patients with clinically staged T3N1 (n = 20) or T3N0 (n = 5) rectal cancer received neoadjuvant therapy with radiotherapy (50.4 Gy in 28 fractions over 5.5 weeks), bevacizumab every 2 weeks (3 doses of 5 mg/kg), and capecitabine (900 mg/m(2) orally twice daily only on days of radiation), followed by surgical resection a median of 7.3 weeks later.

RESULTS

Procedures included abdominoperineal resection (APR; 6 patients), proctectomy with coloanal anastamosis (8 patients), low anterior resection (10 patients), and local excision (1 patient). Eight (32%) of 25 patients had a pathologic complete response, and 6 (24%) of 25 had <10% viable tumor cells in the specimen. No patient had Grade 3 hand-foot syndrome, gastrointestinal toxicity, or significant hematologic toxicity. Three wound complications required surgical intervention (one coloanal anastamostic dehiscence requiring completion APR and two perineal wound dehiscences after initial APR). Five minor complications occurred that resolved without operative intervention. With a median follow-up of 22.7 months (range, 4.5-32.4 months), all patients were alive; one patient has had a recurrence in the pelvis (2-year actuarial rate, 6.2%) and 3 had distant recurrences.

CONCLUSIONS

The addition of bevacizumab to neoadjuvant chemoradiation resulted in encouraging pathologic complete response without an increase in acute toxicity. The impact of bevacizumab on perineal wound and anastamotic healing due to concurrent bevacizumab requires further study.

Comparison of two neoadjuvant chemoradiotherapy regimens for locally advanced rectal cancer: results of the phase III trial ACCORD 12/0405-Prodige 2

PURPOSE

Neoadjuvant chemoradiotherapy is considered a standard approach for T3-4 M0 rectal cancer. In this situation, we compared neoadjuvant radiotherapy plus capecitabine with dose-intensified radiotherapy plus capecitabine and oxaliplatin.

PATIENTS AND METHODS

We randomly assigned patients to receive 5 weeks of treatment with radiotherapy 45 Gy/25 fractions with concurrent capecitabine 800 mg/m(2) twice daily 5 days per week (Cap 45) or radiotherapy 50 Gy/25 fractions with capecitabine 800 mg/m(2) twice daily 5 days per week and oxaliplatin 50 mg/m(2) once weekly (Capox 50). The primary end point was complete sterilization of the operative specimen (ypCR).

RESULTS

Five hundred ninety-eight patients were randomly assigned to receive Cap 45 (n = 299) or Capox 50 (n = 299). More preoperative grade 3 to 4 toxicity occurred in the Capox 50 group (25 v 1%; P < .001). Surgery was performed in 98% of patients in both groups. There were no differences between groups in the rate of conservative surgery (75%) or postoperative deaths at 60 days (0.3%). The ypCR rate was 13.9% with Cap 45 and 19.2% with Capox 50 (P = .09). When ypCR was combined with yp few residual cells, the rate was respectively 28.9% with Cap 45 and 39.4% with Capox 50 (P = .008). The rate of positive circumferential rectal margins (between 0 and 2 mm) was 19.3% with Cap 45 and 9.9% with Capox 50 (P = .02).

CONCLUSION

The benefit of oxaliplatin was not demonstrated and this drug should not be used with concurrent irradiation. Cap 50 merits investigation for T3-4 rectal cancers.

Current evidence-based opinions in the management of adenocarcionoma of the rectum

The management of rectal cancer has drastically evolved over the past two decades as a result of implementation of circular stapling devices and the introduction of neoadjuvant chemoradiation. In spite of current aggressive multimodality treatments, the recurrence rate remains unacceptably high and the expected 5-year survival in patients who develop recurrent disease is dismal. The management of rectal cancer must involve a multidisciplinary approach. An understanding of the biology of rectal tumours may allow for selection of patients who may have an aggressive phenotype allowing for alterations in the operative and neoadjuvant planning. Efforts to improve local control and survival in rectal cancer are the focus of multiple current clinical and preclinical research efforts. Preoperative chemoradiation for and surgical management of rectal cancer, including the laparoscopic approach are areas of dynamic progression. In the present report, we review the current evidence in the new strategies pertaining to the multimodality approach in the management of rectal cancer.

Revised tumor and node categorization for rectal cancer based on surveillance, epidemiology, and end results and rectal pooled analysis outcomes

PURPOSE

The sixth edition of the American Joint Committee on Cancer (AJCC) rectal cancer staging subdivided stage II into IIA (T3N0) and IIB (T4N0) and stage III into IIIA (T1-2N1M0), IIIB (T3-4N1M0), and IIIC (anyTN2M0). Subsequent analyses supported revised substaging of stage III as a result of improved survival with T1-2N2 versus T3-4N2 and survival of T4N1 more similar to T3-4N2 than T3N1. The AJCC Hindgut Taskforce sought population-based validation that depth of invasion interacts with nodal status to affect survival.

METHODS

Surveillance, Epidemiology, and End Results (SEER) population-based data from January 1992 to December 2004 for 35,829 patients with rectal cancer were compared with rectal pooled analysis data (3,791 patients). T4N0 cancers were stratified by tumors that perforate visceral peritoneum (T4a) versus tumors that invade or are adherent to adjacent organs or structures (T4b). N1 and N2 were stratified by number of positive nodes as follows: N1a/N1b (one v two to three nodes) and N2a/N2b (four to six v > or = seven nodes). Five-year observed and relative survival rates were obtained for each TN category.

RESULTS

SEER rectal cancer analyses confirm that T1-2N2 cancers have better prognosis than T3-4N2, T4bN1 have similar prognosis to T4N2, T1-2N1 have similar prognosis to T2N0/T3N0, and T1-2N2a have similar prognosis to T2N0/T3N0 (T1N2a) or T4aN0 (T2N2a). Prognosis for T4a lesions is better than T4b by N category. The number of positive nodes affects prognosis.

CONCLUSION

This SEER population-based rectal cancer analysis validates the rectal pooled analyses and supports the shift of T1-2N2 lesions from IIIC to IIIA or IIIB and T4bN1 from IIIB to IIIC. SEER outcomes support subdividing T4, N1, and N2 and revised substaging of stages II and III. Survival by TN category suggests a complex biologic interaction between depth of invasion and nodal status.

Rectal cancer and importance of chemoradiation in the treatment

Neoadjuvant chemoradiation is used as a preoperative standard treatment for the majority of patients with Stage II/III rectal cancers and, in attempt to facilitate surgical intervention, reduce the rate of local recurrence and improve overall outcomes in patients suffering from this malignancy. However, this modality results in a wide range of clinical responses. In many cases, a pathological complete response is achieved, while in others, receiving the same form of treatment, the tumor continues to grow. The specific phenotype of the tumor plays a major role in rendering tumor cells a survival advantage to the cytotoxic effects of chemoradiation. Several factors participating in proliferation, cell cycle, apoptosis and hypoxiahave been investigated under a variety of conditions in pre-irradiated tissues and post-irradiated tumors. Mutations in the genes of these pathways have shown to lead to resistance to chemoradiation. This chapter describes colon cancer with emphasis on the molecular mechanisms that may lead to chemoradio-resistance of cells with cytotoxically induced DNA injury in rectal cancer.

Improved patient and regimen selection in locally advanced rectal cancer: who, how, and what next?

Before the advent of neoadjuvant chemoradiation therapy (NCRT) for locally advanced rectal cancer, local failure represented half of treatment failures. The German Rectal Cancer Study Group trial demonstrated that NCRT along with total mesorectal excision can improve local control and the rate of sphincter-preserving surgery. Thus, the National Comprehensive Cancer Network now recommends NCRT as the standard of care for stage III and IV rectal cancer. Recent trials and analysis have questioned accepted wisdom regarding patient selection for NCRT and methods of administration. EORTC 22921 demonstrated that the addition of chemotherapy to radiation therapy, regardless of timing, improved local control but not overall survival, and subgroup analysis from this study generated the hypothesis that the subgroup of patients with good pathologic response to NCRT would benefit the most from additional chemotherapy following surgery. The prognosis of rectal cancer is stage dependent, and 2 major analyses question whether T1/2 N1 and T3 N0 patients benefit from NCRT. Application of the results from these studies is hindered by imperfections in staging. Future improvement in patient selection might result from biologic analysis of tumor sensitivity. NCRT might be improved with the use of oral fluoropyrimidines and perhaps the addition of a second agent such as oxaliplatin, irinotecan, or cetuximab. Improvements in radiation, such as the use of more conformal techniques, might decrease the toxicity of therapy. Given the success of NCRT in improving local control, distant metastasis now predominates as the cause of treatment failure, and larger gains will likely be made from improvements in adjuvant chemotherapy.

Multidisciplinary treatment of locally advanced rectal cancer: a literature review. Part 1

In Western countries, colorectal cancer is the third most common cancer in terms of incidence and mortality. The management of rectal cancer has undergone and continues to undergo significant evolutions. In the last two decades, new multimodality strategies have been developed. Multimodality treatments have improved the prognosis of locally advanced rectal cancer with local recurrences decreasing from 40% to < 10% and overall survival increasing from 50% to 75% in the last 40 years. This review discusses the role of neoadjuvant chemoradiotherapy regimens used in the standard combined modality treatment programs for rectal cancer and focuses on the ongoing research to improve these regimens.

Multidisciplinary Rectal Cancer Management: 2nd European Rectal Cancer Consensus Conference (EURECA-CC2)

BACKGROUND AND PURPOSE

During the first decade of the 21st century a number of important European randomized studies were published. In order to help shape clinical practice based on best scientific evidence from the literature, the International Conference on 'Multidisciplinary Rectal Cancer Treatment: Looking for an European Consensus' (EURECA-CC2) was organized in Italy under the endorsement of European Society of Medical Oncology (ESMO), European Society of Surgical Oncology (ESSO), and European Society of Therapeutic Radiation Oncology (ESTRO).

METHODS

Consensus was achieved using the Delphi method. The document was available to all Committee members as a web-based document customized for the consensus process. Eight chapters were identified: epidemiology, diagnostics, pathology, surgery, radiotherapy and chemotherapy, treatment toxicity and quality of life, follow-up, and research questions. Each chapter was subdivided by a topic, and a series of statements were developed. Each member commented and voted, sentence by sentence thrice. Sentences upon which an agreement was not reached after voting round # 2 were openly debated during a Consensus Conference in Perugia (Italy) from 11 December to 13 December 2008. A hand-held televoting system collected the opinions of both the Committee members and the audience after each debate. The Executive Committee scored percentage consensus based on three categories: "large consensus", "moderate consensus", and "minimum consensus".

RESULTS

The total number of the voted sentences was 207. Of the 207, 86% achieved large consensus, 13% achieved moderate consensus, and only 3 (1%) resulted in minimum consensus. No statement was disagreed by more than 50% of the members. All chapters were voted on by at least 75% of the members, and the majority was voted on by >85%.

CONCLUSIONS

This Consensus Conference represents an expertise opinion process that may help shape future programs, investigational protocols, and guidelines for staging and treatment of rectal cancer throughout Europe.

Mechanisms of resistance to ionizing radiation in rectal cancer

While patients with breast cancers are not subjected to the adverse side effects of tamoxifen or trastuzumab if their tumors are negative for estrogen, progesterone or Her-2/Neu, neoadjuvant ionizing radiation with concurrent chemotherapeutic agents is administered almost universally to patients with stage II/III rectal cancers. There is, however, a tremendously wide range of response to this preoperative modality from complete pathological response to continuous tumor growth in patients receiving the same form of treatment. The specific phenotype of the tumor plays a major role in rendering tumor cells survival advantage to the cytotoxic effects of chemoradiation. Pathways such as proliferation, cell cycle, apoptosis and hypoxia have been investigated under a variety of conditions in preirradiated tissues and postirradiated tumors. This article reviews the current evidence available to identify a molecular profile predictive of the best response to ionizing radiation.

Curcumin modulates the radiosensitivity of colorectal cancer cells by suppressing constitutive and inducible NF-kappaB activity

PURPOSE

Radiation therapy is an integral part of the preoperative treatment of rectal cancers. However, only a minority of patients achieve a complete pathologic response to therapy because of resistance of these tumors to radiation therapy. This resistance may be mediated by constitutively active pro-survival signaling pathways or by inducible/acquired mechanisms in response to radiation therapy. Simultaneous inhibition of these pathways can sensitize these tumors to radiation therapy.

METHODS AND MATERIALS

Human colorectal cancer cells were exposed to clinically relevant doses of gamma rays, and the mechanism of their radioresistance was investigated. We characterized the transcription factor nuclear factor-kappaB (NF-kappaB) activation as a mechanism of inducible radioresistance in colorectal cancer and used curcumin, the active ingredient in the yellow spice turmeric, to overcome this resistance.

RESULTS

Curcumin inhibited the proliferation and the post-irradiation clonogenic survival of multiple colorectal cancer cell lines. Radiation stimulated NF-kappaB activity in a dose- and time-dependent manner, whereas curcumin suppressed this radiation-induced NF-kappaB activation via inhibition of radiation-induced phosphorylation and degradation of inhibitor of kappaB alpha, inhibition of inhibitor of kappaB kinase activity, and inhibition of Akt phosphorylation. Curcumin also suppressed NF-kappaB-regulated gene products (Bcl-2, Bcl-x(L), inhibitor of apoptosis protein-2, cyclooxygenase-2, and cyclin D1).

CONCLUSIONS

Our results suggest that transient inducible NF-kappaB activation provides a prosurvival response to radiation that may account for development of radioresistance. Curcumin blocks this signaling pathway and potentiates the antitumor effects of radiation therapy.

Preoperative downstaging chemoradiation with concurrent irinotecan and capecitabine in MRI-defined locally advanced rectal cancer: a phase I trial (NWCOG-2)

Background:

The aim of this study was to investigate the safety of neoadjuvant chemoradiation using radiotherapy (RT) combined with concurrent capecitabine and irinotecan for locally advanced rectal cancer before surgery.

Methods:

Forty-six patients were recruited and treated on the basis that MRI scanning had shown poor-risk tumours with threatening (⩽1 mm) or involvement of the mesorectal fascia. Conformal RT was given using 3 or 4 fields at daily fractions of 1.8 Gy on 5 days per week to a total dose of 45 Gy. Concurrently oral capecitabine was given twice daily throughout radiotherapy continuously from days 1 to 35 and intravenous irinotecan was given once per week during weeks 1 to 4 of RT. Dose levels were gradually escalated as follows. Dose level 1: capecitabine 650 mg m⁻² b.i.d. and irinotecan 50 mg m⁻²; Dose level 2: capecitabine 650 mg m⁻² b.i.d. and irinotecan 60 mg m⁻²; Dose level 3: capecitabine 825 mg m⁻² b.i.d. and irinotecan 60 mg m²; Dose level 4: capecitabine 825 mg m⁻² b.i.d. and irinotecan 70 mg m⁻².

Results:

Diarrhoea (grade 3, no grade 4) was the main serious acute toxicity with lesser degrees of fatigue, neutropenia, anorexia and palmar-plantar erythrodysesthesia. The recommended dose for future study was dose level 2 at which 3 of 14 patients (21%) developed grade 3 diarrhoea. Postoperative complications included seven pelvic or wound infections and two anastomotic and two perineal wound dehiscences. There were no deaths in the first 30 days postoperatively. Of 41 resected specimens, 11 (27%) showed a pathological complete response (pCR) and five (12%) showed an involved circumferential resection margin (defined as ⩽1 mm). The 3-year disease-free survival (intent-to-treat) was 53.2%.

Conclusion:

In patients with poor-risk MRI-defined locally advanced rectal cancer threatening or involving the mesorectal fascia, preoperative chemoradiation based on RT at 45 Gy in 25 daily fractions over 5 weeks with continuous daily oral capecitabine at 650 mg m⁻² b.i.d. days 1–35 and weekly IV irinotecan at 60 mg m⁻² weeks 1–4, provides acceptable acute toxicity and postoperative morbidity with encouraging response and curative resection rates.

Radiosensitization of HT-29 cells and xenografts by the nitric oxide donor DETANONOate

BACKGROUND

Mechanisms of radioresistance in rectal cancer remain unclear.

OBJECTIVES

To determine mechanisms of radioresistance in rectal cancer cells and to assess the role of the nitric oxide donor DETANONOate as a radiosensitizing agent.

METHODS

Survival was determined by clonogenic assays, apoptosis by PARP-1 cleavage, and phenotypic differences by Western blot analysis. SCID mice bearing HT-29 xenografts were treated with ionizing radiation (IR) [2.0 Gy x 5], DETANONOate [0.4 mg/kg i.p.], or combination treatment.

RESULTS

Colorectal cancer HT-29-p53-null cells were resistant and HCT-116-p53 wild-type cells sensitive to IR, which correlated with cleaved PARP-1. Increased levels of p21 occurred in HCT-116 cells, while Bcl-2 and survivin were elevated in HT-29 cells. Radiosensitization was achieved with a substantial elevation of cleaved PARP-1 in DETANONOate-HT-29-treated versus control cells, which was accompanied by elevation of p21, p27, and BAX, and a concomitant decrease in Bcl-2. SCID mice bearing HT-29 xenografts demonstrated a 37.6%, 51.1%, and 70.1% inhibition in tumor growth in mice receiving IR, DETANONOate, and combination treatment versus control, respectively.

CONCLUSIONS

Radioresistant HT-29 cells are p53-null and have substantially decreased levels of p21. DETANONOate radiosensitized HT-29 cells in vitro and in vivo by an additive effect in apoptosis.

Future directions in neoadjuvant therapy of rectal cancer: maximizing pathological complete response rates

Neoadjuvant therapy is widely accepted as the current standard of care for localized rectal cancer. Downstaging of disease has been significantly improved and pathological complete response rates (pCR) which were historically below 10% with preoperative radiation alone, now range from 15% to 30% with preoperative chemo-radiation. While the availability of new chemotherapeutic drugs (Irinotecan, Oxaliplatin, etc.) and molecular targeted agents (Bevacizamab, Cetuximab, etc.) hold a great deal of promise, results of recent studies indicate that the pCR rate with neoadjuvant therapy appears to have plateaued at 20-30%. The use of more intensive multidrug combinations has, however, significantly increased the toxicity of treatment. New paradigms in neoadjuvant therapy are therefore needed to further improve results of treatment. This review presents strategies for neoadjuvant therapy, with the potential to improve pCR rates and also survival of patients.

Is the increasing role of Transanal Endoscopic Microsurgery in curation for T1 rectal cancer justified? A systematic review

Driven by the aim to avoid a permanent colostomy and also the morbidity and mortality of major radical surgery for rectal cancer, the proportion of patients with rectal cancer treated by local excision has increased the last ten years or so. In T1 carcinomas local excision is considered a curative option in selected tumors. However, the scientific base upon which this treatment regimen is built remains controversial. In this systematic review we try to elucidate current literature regarding local excision for T1 rectal carcinomas. Several questions are addressed. First, is there enough evidence to propagate LE as a curative option in selected (T1) rectal carcinomas? Second, if LE is justified, which technique should be the method of choice? Third, can we adequately identify, pre- and postoperatively, tumors suitable for LE? Finally, future perspectives are discussed.