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

Phase 2 study of preoperative radiation with concurrent capecitabine, oxaliplatin, and bevacizumab followed by surgery and postoperative 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX), and bevacizumab in patients with locally advanced rectal cancer: ECOG 3204

BACKGROUND

Recent studies have demonstrated the feasibility of combining oxaliplatin with 5-fluorouracil (5-FU) or capecitibine and radiation therapy. The addition of bevacizumab to chemotherapy improves overall survival for metastatic disease. We initiated a phase 2 trial to evaluate preoperative capecitabine, oxaliplatin, and bevacizumab with radiation therapy followed by surgery and postoperative 5-FU, leucovorin, oxaliplatin (FOLFOX) and bevacizumab for locally advanced rectal cancer.

METHODS

Fifty-seven patients with resectable T3/T4 rectal adenocarcinoma were enrolled. Preoperative treatment was capecitabine (825 mg/m(2) twice daily from Monday to Friday), oxaliplatin (50 mg/m(2) weekly), bevacizumab (5 mg/kg on days 1, 15, 29), and radiation therapy (50.4 Gy). Surgery was performed by 6 weeks after neoadjuvant therapy. Beginning 8 to 12 weeks after surgery, patients received FOLFOX plus bevacizumab (5 mg/kg) every 2 weeks for 12 cycles.

RESULTS

Fifty-four of 57 enrolled patients were eligible. Forty-nine (91%) patients completed preoperative therapy and underwent surgery. Nine patients (17%; 90% confidence interval, 9%-27%) achieved pathologic complete response. Thirty-two patients (59%) experienced pathologic tumor downstaging, and 53% and 15% of patients experienced worst grade 3 and grade 4 acute toxicity, respectively. Forty-seven percent of patients who underwent surgery experienced a surgical complication.

CONCLUSIONS

The primary endpoint of a 30% pathologic complete response rate was not reached; however, the majority of patients experienced pathologic downstaging with this regimen. Increased wound-healing delays and complications may have been related to the addition of bevacizumab, oxaliplatin, or both. Continued observation of these patients will establish the long-term morbidity and efficacy of this combined modality approach.

Phase II trial of preoperative radiochemotherapy with concurrent bevacizumab, capecitabine and oxaliplatin in patients with locally advanced rectal cancer

BACKGROUND

Preoperative radiochemotherapy (RCT) with 5-FU or capecitabine is the standard of care for patients with locally advanced rectal cancer (LARC). Preoperative RCT achieves pathological complete response rates (pCR) of 10-15%. We conducted a single arm phase II study to investigate the feasibility and efficacy of addition of bevacizumab and oxaliplatin to preoperative standard RCT with capecitabine.

METHODS

Eligible patients had LARC (cT3-4; N0/1/2, M0/1) and were treated with preoperative RCT prior to planned surgery. Patients received conventionally fractionated radiotherapy (50.4 Gy in 1.8 Gy fractions) and simultaneous chemotherapy with capecitabine 825 mg/m2 bid (d1-14, d22-35) and oxaliplatin 50 mg/m2 (d1, d8, d22, d29). Bevacizumab 5 mg/kg was added on days 1, 15, and 29. The primary study objective was the pCR rate.

RESULTS

70 patients with LARC (cT3-4; N0/1, M0/1), ECOG < 2, were enrolled at 6 sites from 07/2008 through 02/2010 (median age 61 years [range 39-89], 68% male). At initial diagnosis, 84% of patients had clinical stage T3, 62% of patients had nodal involvement and 83% of patients were M0. Mean tumor distance from anal verge was 5.92 cm (± 3.68). 58 patients received the complete RCT (full dose RT and full dose of all chemotherapy). During preoperative treatment, grade 3 or 4 toxicities were experienced by 6 and 2 patients, respectively: grade 4 diarrhea and nausea in one patient (1.4%), respectively, grade 3 diarrhea in 2 patients (3%), grade 3 obstipation, anal abscess, anaphylactic reaction, leucopenia and neutropenia in one patient (1.4%), respectively. In total, 30 patients (46%) developed postoperative complications of any grade including one gastrointestinal perforation in one patient (2%), wound-healing problems in 7 patients (11%) and bleedings in 2 patients (3%). pCR was observed in 12/69 (17.4%) patients. Pathological downstaging (ypT < cT and ypN ≤ cN) was achieved in 31 of 69 patients (44.9%). All of the 66 operated patients had a R0 resection. 47 patients (68.1%) underwent sphincter preserving surgery.

CONCLUSIONS

The addition of bevacizumab and oxaliplatin to RCT with capecitabine was well tolerated and did not increase perioperative morbidity or mortality. However, the pCR rate was not improved in comparison to other trials that used capecitabine or capecitabine/oxaliplatin in preoperative radiochemotherapy.

Neoadjuvant treatment for unresectable rectal cancer: an interim analysis of a multicentre randomized study

PURPOSE

To present an interim analysis of the trial comparing two neoadjuvant therapies for unresectable rectal cancer.

METHODS

Patients with fixed cT3 or cT4 or locally recurrent rectal cancer without distant metastases were randomized to either 5 × 5 Gy and 3 courses of FOLFOX4 (schedule I) or 50.4 Gy delivered in 28 fractions given simultaneously with 5-Fu, leucovorin and oxaliplatin (schedule II). Surgery in both groups was performed 12 weeks after the beginning of radiation and 6 weeks after neoadjuvant treatment.

RESULTS

49 patients were treated according to schedule I and 48 according to schedule II. Grade III+ acute toxicity was observed in 26% of patients in group I and in 25% in group II. There were two toxic deaths, both in group II. The microscopically radical resection (primary endpoint) rate was 73% in group I and 71% in group II. Overall and severe postoperative complications were recorded in 27% and 9% of patients vs. 16% and 7%, respectively. Pathological complete response was observed in 21% of the patients in group I and in 9% in group II.

CONCLUSIONS

The interim analysis revealed no major differences in acute toxicity and local efficacy between the two evaluated strategies.

Oxaliplatin for colorectal cancer: recent evidence from clinical trials

SUMMARY Oxaliplatin, a second-generation platinum analog, has evolved as one of the most important therapeutic agents in the treatment of both metastatic colorectal cancer and stage II/III colon cancer. Moreover, oxaliplatin is currently being investigated in the perioperative treatment of locally advanced rectal cancer. Oxaliplatin can be safely combined with fluoropyrimidines, irinotecan, bevacizumab and EGF receptor antibodies, resulting in increased response rates and delayed progression. In combination with EGF receptor antibodies, fluoropyrimidine schedules need to be cautiously considered. Treatment strategies to limit oxaliplatin-induced neurotoxicity by discontinuous administration schedules (e.g., induction followed by maintenance, followed by reinduction or intermittent treatment) are available.

Optimal time interval between neoadjuvant chemoradiotherapy and surgery for rectal cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) has been proven to increase local control in rectal cancer, but the optimal interval between CRT and surgery is still unclear. The purpose of this study was to analyse the influence of variations in clinical practice regarding timing of surgery on pathological response at a population level.

METHODS

All evaluable patients who underwent preoperative CRT for rectal cancer between 2009 and 2011 were selected from the Dutch Surgical Colorectal Audit. The interval between radiotherapy and surgery was calculated from the start of radiotherapy. The primary endpoint was pathological complete response (pCR; pathological status after chemoradiotherapy (yp) T0 N0).

RESULTS

A total of 1593 patients were included. The median interval between radiotherapy and surgery was 14 (range 6-85, interquartile range 12-16) weeks. Outcome measures were calculated for intervals of less than 13 weeks (312 patients), 13-14 weeks (511 patients), 15-16 weeks (406 patients) and more than 16 weeks (364 patients). Age, tumour location and R0 resection rate were distributed equally between the four groups; significant differences were found for clinical tumour category (cT4: 17·3, 18·4, 24·5 and 26·6 per cent respectively; P = 0·010) and clinical metastasis category (cM1: 4·4, 4·8, 8·9 and 14·9 per cent respectively; P < 0·001). Resection 15-16 weeks after the start of CRT resulted in the highest pCR rate (18·0 per cent; P = 0·013), with an independent association (hazard ratio 1·63, 95 per cent confidence interval 1·20 to 2·23). Results for secondary endpoints in the group with an interval of 15-16 weeks were: tumour downstaging, 55·2 per cent (P = 0·165); nodal downstaging, 58·6 per cent (P = 0·036); and (near)-complete response, 23·2 per cent (P = 0·124).

CONCLUSION

Delaying surgery until the 15th or 16th week after the start of CRT (10-11 weeks from the end of CRT) seemed to result in the highest chance of a pCR.

Radiation therapy in anal and rectal cancer

Historically, squamous cell carcinoma of the anal canal was treated with abdominoperineal resection. Nigro discovered that radiation therapy combined with 5-fluorouracil and mitomycin resulted in high rates of local control and colostomy-free and overall survival without surgical intervention. Recent advances include the integration of PET into staging, radiation treatment planning, disease monitoring, and the use of intensity-modulated radiation therapy. For rectal cancer, clinical trials have established the role for neoadjuvant therapy for T3-4 and/or node-positive tumor presentations. Chemotherapy and targeted agents are under study in both anal and rectal cancers to improve on the standard combinations of chemotherapy and radiation.

Management of distal rectal cancer: results from a national survey

Owing to the complexity of distal rectal cancer its management requires a multidisciplinary approach. The diagnosis and the response after neoadjuvant chemoradiotherapy are not easy to assess and therefore the surgical approach is heterogeneous. The purpose of this survey is to evaluate the experiences of members of the Italian Society of Surgery in diagnosis and treatment strategies for rectal cancer and compare it with international practice. A questionnaire was devised comprising 18 questions with 11 sub-items making a total of 29 questions and submitted online to all the 2,500 members of the SIC starting from July 2010. The survey was completed in June 2011. The overall response rate was 17.8 % (444). The majority of the Italian surgeons' responses were in line with the international consensus reflecting the complex management of distal rectal cancer. Other opinions, especially those on staging, diverge from the common view of MRI being the gold standard in the assessment of loco-regional diffusion of the disease and on the superiority of FDG PET-CT versus CT for systemic staging. The timing for the re-staging and for surgery following neoadjuvant chemoradiotherapy does not reflect the international opinion. Italian surgeons are also exposed to the common difficulties encountered internationally in the management of distal rectal cancer. Probably, the implementation of an Italian rectal cancer registry and of many national and international multicentre studies may improve the management of rectal cancer in Italy.

Patterns of Practice in the Radiation Therapy Management of Rectal Cancer: Survey of the Interregional Group Piedmont, Valle d'Aosta and Liguria of the “Associazione Italiana di Radioterapia Oncologica (AIRO)”

Aims and background

To report the survey about the main aspects on the use of radiotherapy for the treatment of rectal cancer in Piedmont and Liguria.

Methods and study design

Sixteen centers (11 from Piedmont and 5 from Liguria) received and answered by email a questionnaire data base about clinical and technical aspects of the treatment of rectal cancer. All data were incorporated in a single data base and analyzed.

Results

Data regarding 593 patients who received radiotherapy for rectal cancer during the year 2009 were collected and analyzed. Staging consisted in colonoscopy, thoracic and abdominal CT, pelvic MRI and endoscopic ultrasound. PET/CT was employed to complete staging and in the treatment planning in 12/16 centers (75%). Neoadjuvant radiotherapy was employed more frequently than adjuvant radiotherapy (50% vs 36.4%), using typically a total dose of 45 Gy with 1.8 Gy/fraction. Concurrent chemoradiation with 5-fluorouracil or capecitabine was mainly employed in neoadjuvant and adjuvant settings, whereas oxaliplatin alone or in combination with 5-FU or capecitabine and leucovorin was commonly employed as the adjuvant agent. The median interval from neoadjuvant treatment to surgery was 7 weeks after long-course radiotherapy and 8 days after short-course radiotherapy. The pelvic total dose of 45 Gy in the adjuvant setting was the same in all the centers. Doses higher than 45 Gy were employed with a radical intent or in case of positive surgical margins. Hypofractionated regimens (2.5, 3 Gy to a total dose of 35–30 Gy) were used in the palliative setting. No relevant differences were observed in target volume definition and patient setup. Twenty-six patients (4.4%) developed grade 3 acute toxicity. Follow-up was scheduled in a similar way in all the centers.

Conclusions

No relevant differences were found among the centers involved in the survey. The approach can help clinicians to address important clinical questions and to improve consistency and homogeneity of treatments.

Which way is forward in the treatment of rectal cancer?

Preoperative 5-fluorouracil-based chemoradiation with optimal surgery provides very effective local control in locally advanced rectal cancer. Does adding oxaliplatin as a radiosensitizer provide any additional benefit? Is more always better?

Multiplexed protein signal pathway mapping identifies patients with rectal cancer that responds to neoadjuvant treatment

BACKGROUND

Currently there is no reliable technique for predicting clinical or pathologic complete tumor response after radiochemotherapy (RCT) in patients with rectal cancer. We applied reverse phase protein microarray (RPMA) technology to find a signal pathway that may predict the response to preoperative treatment.

PATIENTS AND METHODS

Fifteen rectal cancer samples were collected during preoperative RCT. Seven patients had a good response to preoperative therapy (Mandard grade I-II) and 8 patients had a poor response (Mandard grade III-V). Using laser capture microdissection (LCM) and RPMA analysis, we measured the phosphorylation level of nearly 80 end points and analyzed the signaling pathways.

RESULTS

We identified 4 signaling proteins whose phosphorylation levels were significantly different (P < .05) between the good vs. poor responders; CHK2 and β-catenin were more highly phosphorylated in poor responders, whereas PDK1 and glycogen synthase kinase (GSK)-3α/β had lower phosphorylation levels in poor responders. Interestingly GSK-3α/β, β-catenin, and PDK1 are all present in the phosphatidylinositol-3-kinase (PI3K)-AKT signaling pathway.

CONCLUSIONS

Based on our results, we hypothesize that the activating state of the PI3K-AKT pathway can stratify patients who could benefit most from neoadjuvant treatment. Moreover, identification of theranostic targets has the potential to pinpoint new therapeutic strategies for the nonresponsive population.

Past, present, and future of radiotherapy for the benefit of patients

Radiotherapy has been driven by constant technological advances since the discovery of X-rays in 1895. Radiotherapy aims to sculpt the optimal isodose on the tumour volume while sparing normal tissues. The benefits are threefold: patient cure, organ preservation and cost-efficiency. The efficacy and tolerance of radiotherapy were demonstrated by randomized trials in many different types of cancer (including breast, prostate and rectum) with a high level of scientific evidence. Such achievements, of major importance for the quality of life of patients, have been fostered during the past decade by linear accelerators with computer-assisted technology. More recently, these developments were augmented by proton and particle beam radiotherapy, usually combined with surgery and medical treatment in a multidisciplinary and personalized strategy against cancer. This article reviews the timeline of 100 years of radiotherapy with a focus on breakthroughs in the physics of radiotherapy and technology during the past two decades, and the associated clinical benefits.

Phase II study of preoperative chemoradiation with S-1 plus oxaliplatin in patients with locally advanced rectal cancer

A phase II study of preoperative chemoradiation (CRT) with S-1 plus oxaliplatin in patients with locally advanced rectal cancer was conducted. The total radiotherapy dose was 50.4 Gy. Chemotherapy consisted of oxaliplatin 50 mg/m(2) on days 1, 8, 22 and 29 and S-1 80 mg/m(2) per day on days 1-14 and 22-35. The tumor apparent diffusion coefficient (ADC) was measured using diffusion-weighted magnetic resonance imaging (DW-MRI) before and after CRT. Total mesorectal excision was performed within 6 ± 2 weeks. The primary end-point was the pathological complete response (pCR) rate. A total of 38 patients were enrolled. The pCR rate was 22.9% (8/35; 95% CI, 10.9-42.1), and 10 (28.6%) patients showed near-total tumor regression. There was no grade 4 adverse event, and grade 3 adverse events included leukopenia (5.4%), diarrhea (5.4%), anorexia (2.7%) and nausea (2.7%). The tumor ADC was calculated in 38 patients (including those who participated in the phase I study). The post-CRT ADC (P = 0.037) and the percentage change in ADC (P = 0.026) were significantly correlated with pathological response. In conclusion, preoperative CRT with S-1 plus oxaliplatin showed promising results in pathological responses and favorable toxicity profiles.

Neoadjuvant short- or long-term radio(chemo)therapy for rectal cancer: how and who should be treated?

There are two general approaches to preoperative radiotherapy (RT) in rectal cancer: short-course (25 Gy in 5 fractions) radiation with immediate surgery and long-course 5-fluorouracil (5-FU)-based chemoradiotherapy (CRT; 50.4 Gy in 28 fractions) with surgery scheduled 6-8 weeks thereafter. While it is clear that downsizing and downstaging effects are more pronounced with long-course CRT and delayed surgery, a Polish randomized trial and, more recently, an Australian phase III trial demonstrated no significant differences in long-term oncologic outcomes and late toxicity rates between either preoperative concept. Ongoing studies currently address short-course preoperative RT with a longer interval to surgery (Stockholm III trial), and short-course RT with sequential combination chemotherapy in patients with synchronous distant metastasis. With respect to the long-course CRT approach, newer-generation chemotherapeutics as well as molecularly targeted agents have been tested within phase I-III studies, both as induction/adjuvant chemotherapy as well as during concomitant CRT. Evidently, the monolithic approaches to either apply the same schedule of preoperative 5-FU-based CRT to all patients with TNM stage II/III rectal cancer or to give preoperative short-course RT for all patients with resectable rectal cancer irrespective of tumor stage and location need to be questioned. The inclusion of different multimodal treatments into the surgical oncological concept, adapted to tumor location, stage, and individual patient risk factors and preferences is upcoming. Clearly, future developments will aim at identifying and selecting patients for ideal treatment alternatives.

[Radiotherapy of rectal cancer]

CLINICAL ISSUE

Despite improved screening options, most patients with rectal cancer are diagnosed at a locally advanced disease stage. STANDARD TREATMENT/PRACTICAL RECOMMENDATIONS: The treatment strategy includes preoperative radiochemotherapy as a cornerstone in order to improve sphincter preservation and local control. It is evident that radiotherapy can achieve improved local control even if optimal surgery (total mesorectal excision TME) is performed. TREATMENT INNOVATIONS, FUTURE PROSPECTS: Whether the neoadjuvant therapy should be applied as a long-term or short-term schedule is controversially discussed. The benefit of newer agents to improve systemic control is still under investigation. Modern radiotherapy techniques increase the effectiveness of radiochemotherapy and may reduce therapy-associated toxicity.

Update and debate issues in surgical treatment of middle and low rectal cancer

Based on a review of the literature, this paper provides an update on surgical treatment of middle and low rectal cancer and discusses issues of debate surrounding that treatment. The main goal of the surgical treatment of rectal cancer is radical resection of the tumor and surrounding lymphatic tissue. Local excision of early rectal cancer can be another treatment option, in which the patient can avoid possible complications related to radical surgery. Neoadjuvant chemoradiation therapy (CRT) has been recommended for patients with cT3-4N0 or any T N+ rectal cancer because CRT shows better local control and less toxicity than adjuvant CRT. However, recent clinical trials showed promising results for local excision after neoadjuvant CRT in selected patients with low rectal cancer. In addition, the "wait and see" concept is another modality that has been reported for the management of tumors that show complete clinical remission after neoadjuvant CRT. Although radical surgery for middle and low rectal cancer is the cornerstone therapy, an ultralow anterior resection with or without intersphincteric resection (ISR) has become an alternative standard surgical method for selected patients. Many studies have reported on the oncological safety of the ISR, but few of them have addressed the issue the functional outcome. Furthermore, an abdominoperineal resection (APR) has problems with high rates of tumor perforations and positive circumferential resection margins, and those factors have contributed to its having a high rate of local recurrence and a poor survival rate for rectal cancer compared with sphincter-saving procedures. Recently, great efforts have been made to reduce these problems, and the total levator excision or the extended APR concept has emerged. Surgical management for low rectal cancer should aim to radically excise the tumor and to preserve as much of the sphincter function as possible by using multidisciplinary approaches. However, further prospective clinical trials are needed for tailored treatment of rectal cancer patients.

Clinical outcome of the ACCORD 12/0405 PRODIGE 2 randomized trial in rectal cancer

PURPOSE

The ACCORD 12 trial investigated the value of two different preoperative chemoradiotherapy (CT-RT) regimens in T3-4 Nx M0 resectable rectal cancer. Clinical results are reported after follow-up of 3 years.

PATIENTS AND METHODS

Between November 2005 and July 2008, a total of 598 patients were randomly assigned to preoperative CT-RT with CAP45 (45-Gy RT for 5 weeks with concurrent capecitabine) or CAPOX50 (50-Gy RT for 5 weeks with concurrent capecitabine and oxaliplatin). Total mesorectal excision was planned 6 weeks after CT-RT. The primary end point was sterilization of the operative specimen, which was achieved in 13.9% versus 19.2% of patients, respectively (P = .09). Clinical results were analyzed for all randomly assigned patients according to the intention-to-treat principle.

RESULTS

At 3 years, there was no significant difference between CAP45 and CAPOX50 (cumulative incidence of local recurrence, 6.1% v 4.4%; overall survival, 87.6% v 88.3%; disease-free survival, 67.9% v 72.7%). Grade 3 to 4 toxicity was reported in four patients in the CAP45 group and in two patients in the CAPOX50 group. Bowel continence, erectile dysfunction, and social life disturbance were not different between groups. In multivariate analysis, the sterilization rate (Dworak score) of the operative specimen was the main significant prognostic factor (hazard ratio, 0.32; 95% CI, 0.21 to 0.50).

CONCLUSION

At 3 years, no significant difference in clinical outcome was achieved with the intensified CAPOX regimen. When compared with other recent randomized trials, these results indicate that concurrent administration of oxaliplatin and RT is not recommended.

Treatment of locally advanced rectal cancer: Controversies and questions

Rectal cancers extending through the rectal wall, or involving locoregional lymph nodes (T3/4 or N1/2), have been more difficult to cure. The confines of the bony pelvis and the necessity of preserving the autonomic nerves makes surgical extirpation challenging, which accounts for the high rates of local and distant relapse in this setting. Combined multimodality treatment for rectal cancer stage II and III was recommended from National Institute of Health consensus. Neoadjuvant chemoradiation using fluoropyrimidine-based regimen prior to surgical resection has emerged as the standard of care in the United States. Optimal time of surgery after neoadjuvant treatment remained unclear and prospective randomized controlled trial is ongoing. Traditionally, 6-8 wk waiting period was commonly used. The accuracy of studies attempting to determine tumor complete response remains problematic. Currently, surgery remains the standard of care for rectal cancer patients following neoadjuvant chemoradiation, whereas observational management is still investigational. In this article, we outline trends and controversies associated with optimal pre-treatment staging, neoadjuvant therapies, surgery, and adjuvant therapy.

ESMO Consensus Guidelines for management of patients with colon and rectal cancer. a personalized approach to clinical decision making

Colorectal cancer (CRC) is the most common tumour type in both sexes combined in Western countries. Although screening programmes including the implementation of faecal occult blood test and colonoscopy might be able to reduce mortality by removing precursor lesions and by making diagnosis at an earlier stage, the burden of disease and mortality is still high. Improvement of diagnostic and treatment options increased staging accuracy, functional outcome for early stages as well as survival. Although high quality surgery is still the mainstay of curative treatment, the management of CRC must be a multi-modal approach performed by an experienced multi-disciplinary expert team. Optimal choice of the individual treatment modality according to disease localization and extent, tumour biology and patient factors is able to maintain quality of life, enables long-term survival and even cure in selected patients by a combination of chemotherapy and surgery. Treatment decisions must be based on the available evidence, which has been the basis for this consensus conference-based guideline delivering a clear proposal for diagnostic and treatment measures in each stage of rectal and colon cancer and the individual clinical situations. This ESMO guideline is recommended to be used as the basis for treatment and management decisions.

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.

Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

Background

The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials.

Methods

Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models.

Results

Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth.

Conclusions

Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials.

Elevated CEA levels and low distance of the tumor from the anal verge are predictors of incomplete response to chemoradiation in patients with rectal cancer

BACKGROUND

The objective of this study was to evaluate pretreatment clinical parameters as predictive factors for complete pathological response after long-term chemoradiotherapy (RCT) for rectal cancer. Tumor downstaging after RCT for rectal cancer can be obtained in half of cases, whereas a complete pathological response (CPR) is reported to range between 15 and 30%. It is not possible to foresee before therapies who will respond.

METHODS

Patients with stage II-III rectal cancer that had undergone RCT and rectal resection between January 1995 and October 2010 were considered. Patients were divided in those who achieved a CPR, "CR" group, and those who did not achieve a CPR, "NCR" group. Univariate and multivariate analyses between groups were performed considering the clinical parameters: gender, age, ASA score, preoperative hematic CEA, tumor grading; distance of the tumor from the anal verge, maximum tumor diameter, TNM stage, and neoadjuvant treatment details.

RESULTS

Among 260 patients, 43 (16.5%) achieved a CPR. The two groups resulted homogeneous for age, sex, pretreatment status, and tumor stage. A CEA <5 ng/dl and distance from anal verge >5 cm were correlated with CPR at multivariate analysis. Patients with both these conditions presented a significantly higher CPR rate (30.6%) as well as improved 5-year survival. CPR was also correlated with improved survival.

CONCLUSIONS

Very low tumors with a high serum CEA are very unlikely to reach a CPR. The predictive value of these easily available clinical factors should not be underestimated, and better therapeutic strategies for these tumors are needed.

Randomized trial of short-course radiotherapy versus long-course chemoradiation comparing rates of local recurrence in patients with T3 rectal cancer: Trans-Tasman Radiation Oncology Group trial 01.04

PURPOSE

To compare the local recurrence (LR) rate between short-course (SC) and long-course (LC) neoadjuvant radiotherapy for rectal cancer.

PATIENTS AND METHODS

Eligible patients had ultrasound- or magnetic resonance imaging-staged T3N0-2M0 rectal adenocarcinoma within 12 cm from anal verge. SC consisted of pelvic radiotherapy 5 × 5 Gy in 1 week, early surgery, and six courses of adjuvant chemotherapy. LC was 50.4 Gy, 1.8 Gy/fraction, in 5.5 weeks, with continuous infusional fluorouracil 225 mg/m(2) per day, surgery in 4 to 6 weeks, and four courses of chemotherapy.

RESULTS

Three hundred twenty-six patients were randomly assigned; 163 patients to SC and 163 to LC. Median potential follow-up time was 5.9 years (range, 3.0 to 7.8 years). Three-year LR rates (cumulative incidence) were 7.5% for SC and 4.4% for LC (difference, 3.1%; 95% CI, -2.1 to 8.3; P = .24). For distal tumors (< 5 cm), six of 48 SC patients and one of 31 LC patients experienced local recurrence (P = .21). Five-year distant recurrence rates were 27% for SC and 30% for LC (log-rank P = 0.92; hazard ratio [HR] for LC:SC, 1.04; 95% CI, 0.69 to 1.56). Overall survival rates at 5 years were 74% for SC and 70% for LC (log-rank P = 0.62; HR, 1.12; 95% CI, 0.76 to 1.67). Late toxicity rates were not substantially different (Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer G3-4: SC, 5.8%; LC, 8.2%; P = .53).

CONCLUSION

Three-year LR rates between SC and LC were not statistically significantly different; the CI for the difference is consistent with either no clinically important difference or differences in favor of LC. LC may be more effective in reducing LR for distal tumors. No differences in rates of distant recurrence, relapse-free survival, overall survival, or late toxicity were detected.

The role of capecitabine in locally advanced rectal cancer treatment: an update

Preoperative infusional 5-fluorouracil (5-FU) and concurrent radiation therapy (RT) followed by total mesorectal surgery is the current standard of care for locally advanced rectal cancer (LAR). When compared with postoperative 5-FU-based chemoradiation, this strategy is associated with significantly lower rates of local relapse, lower toxicity and better compliance. Capecitabine is a rationally designed oral prodrug that is converted into 5-FU by intracellular thymidine phosphorylase. Substitution of infusional 5-FU with capecitabine is an attractive option that provides a more convenient administration schedule and, possibly, increased efficacy. Indeed, incorporation of capecitabine in combined modality neoadjuvant therapy for LAR has been under intense investigation during the last 10 years. Phase I and II clinical trials showed that a regimen consisting of capecitabine 825mg/m(2) twice daily for 7 days/week continuous oral administration in combination with RT is an active and well tolerated regimen, thereby being the preferred concurrent regimen. The definitive demonstration that efficacy of capecitabine/RT is similar to 5-FU/RT has been provided by the NSABP-R-04 and the German Margit trials. One approach to improve outcomes in rectal cancer is to deliver a second RT-sensitizing drug with effective systemic activity. Oxaliplatin and irinotecan are therefore good candidates. However, two phase III trials demonstrated that incorporation of oxaliplatin to capecitabine with RT did not improve early outcomes and, by contrast, increased toxicity. Capecitabine has also been combined with irinotecan. This regimen showed encouraging results in phase I and II clinical trials, which led to an ongoing phase III clinical trial. New strategies with induction chemotherapy with or without chemoradiation prior to surgery are currently under investigation. Whether or not capecitabine has a role in this setting is being investigated in ongoing trials. Incorporation of agents directed towards new targets, such as anti-epidermal growth factor receptor (EGFR) antibodies or antiangiogenic agents, in combination preoperative regimens, is being hampered by results of early trials in which efficacy outcomes with cetuximab were poor and an excessive rate of surgical complications with bevacizumab was observed. The lack of improvements in efficacy with the addition of cetuximab or bevacizumab in the adjuvant treatment of colon cancer led to concerns about further development of these agents in rectal cancer. The role of capecitabine in the postoperative adjuvant setting is the aim of the ongoing Dutch SCRIPT trial. The prediction of response associated with capecitabine has been based on expression of thymidylate synthase and dihydropyrimidine dehydrogenase, as well as on gene expression arrays. All these procedures require further validation and should be considered as investigational. In conclusion, capecitabine can safely and effectively replace intravenous continuous infusion of 5-FU in the preoperative chemoradiation setting for rectal cancer management. The addition of other new antineoplastic agents to a fluoropyrimidine-based regimen remains investigational.

Progress in rectal cancer treatment

The dramatic improvement in local control of rectal cancer observed during the last decades is to be attributed to attention to surgical technique and to the introduction of neoadjuvant therapy regimens. Nevertheless, systemic relapse remains frequent and is currently insufficiently addressed. Intensification of neoadjuvant therapy by incorporating chemotherapy with or without targeted agents before the start of (chemo)radiation or during the waiting period to surgery may present an opportunity to improve overall survival. An increasing number of patients can nowadays undergo sphincter preserving surgery. In selected patients, local excision or even a "wait and see" approach may be feasible following active neoadjuvant therapy. Molecular and genetic biomarkers as well as innovative imaging techniques may in the future allow better selection of patients for this treatment option. Controversy persists concerning the selection of patients for adjuvant chemotherapy and/or targeted therapy after neoadjuvant regimens. The currently available evidence suggests that in complete pathological responders long-term outcome is excellent and adjuvant therapy may be omitted. The results of ongoing trials will help to establish the ideal tailored approach in resectable rectal cancer.

Multimodal treatment strategies for locally advanced rectal cancer

This review outlines the important multimodal treatment issues associated with locally advanced rectal cancer. Changes to chemotherapy and radiation schema, as well as modern surgical approaches, have led to a revolution in the management of this disease but the morbidity and mortality remains high. Adequate treatment is dependent on precise preoperative staging modalities. Advances in staging via endorectal ultrasound, computed tomography, MRI and PET have improved pretreatment triage and management. Important prognostic factors and their impact for this disease are under investigation. Here we discuss the different treatment options including modern tumor-related surgical approaches, neoadjuvant as well as adjuvant therapies. Further clinical progress will largely depend on the broader implementation of multidisciplinary treatment strategies following the principles of evidence-based medicine.

Rectal cancer: state of the art in 2012

PURPOSE OF REVIEW

To discuss the recent developments of multimodal treatment for patients with local advanced rectal cancer, including incorporation of new chemotherapeutic and targeted agents, and the optimal sequence and timing of treatment components.

RECENT FINDINGS

Five randomized trials have been completed to determine whether the addition of oxaliplatin to preoperative, fluorouracil-based chemoradiotherapy (CRT) offers an advantage compared to single-agent fluorouracil CRT. Early results from the ACCORD 12, STAR-01, and NSAPB R-04 trials did not confirm a significant improvement of early efficacy endpoints with the addition of oxaliplatin, whereas the German CAO/ARO/AIO-04 did. Most of the phase II trials incorporating cetuximab into CRT reported disappointingly low rates of pathologic complete response (pCR); the combination of CRT with VEGF inhibition showed encouraging pCR rates; however, it was associated with increased surgical complications. Novel clinical trials address the role of induction chemotherapy, of delayed, minimal or omitted surgery following CRT, or the omission of radiotherapy for selected patients.

SUMMARY

At this time, the use of oxaliplatin or targeted agents as component of multimodality treatment for rectal cancer outside of a clinical trial is not recommended. The inclusion of different treatment options, according to tumor stage, location, imaging features, and response, will render the multimodal treatment approach of rectal cancer more risk-adapted.

Multicenter phase II clinical trial of preoperative capecitabine with concurrent radiotherapy in patients with locally advanced rectal cancer

INTRODUCTION

To assess pathologic complete response, sphincter preservation rates and toxicity profile of preoperative chemoradiation with capecitabine in resectable locally advanced rectal cancer.

MATERIALS AND METHODS

Fifty-eight patients from six Spanish centers were included (March 2004 to June 2005) with histological/cytological diagnosis of locally advanced rectal cancer, age between 18 and 80 years, ECOG 0-2, adequate bone marrow, renal and hepatic functions. Prior chemotherapy/radiotherapy was not allowed. Preoperative treatment was capecitabine 825 mg/m(2) bid concomitant to radiotherapy (45 + 5.4 Gy boost over 5.5 weeks). Surgery was performed 4-8 weeks after completion of chemoradiotherapy.

RESULTS

Fifty-eight patients were enrolled in this study: 60.3 % males, median age of 64.5 (30.9-78.7) years, 28.6 % with ECOG 0 and 71.4 % with ECOG 1. Median distance of tumor from the anal verge was 7 (1-12) cm. Fifty-two (89.6. %) patients completed preoperative chemoradiotherapy. Primary tumor and node downstaging occurred in 61.1 and 69.6 % of patients, respectively. Surgery was performed in 55 patients (94.8 %): 80 % had negative lymph nodes and 72.7 % underwent sphincter-preserving procedures. A pathologic complete response was observed in 10.5 % (95 % CI 2.5-18.5) of the patients. Main grade I-II toxicities were leucopenia (43.1 %), neutropenia (24.1 %), anemia (36.2 %), diarrhea (32.8 %) and skin disorders (5.1 %), from which diarrhea (6.9 %), leucopenia (1.7 %) and skin disorders (1.7 %) reached grade III. There were no grade IV toxicities.

CONCLUSIONS

Preoperative capecitabine-based chemoradiation is a well-tolerated and effective neoadjuvant treatment for locally advanced rectal cancer that achieves encouraging rates of tumor downstaging.

Multicenter phase II clinical trial of preoperative capecitabine with concurrent radiotherapy in patients with locally advanced rectal cancer

INTRODUCTION

To assess pathologic complete response, sphincter preservation rates and toxicity profile of preoperative chemoradiation with capecitabine in resectable locally advanced rectal cancer.

MATERIALS AND METHODS

Fifty-eight patients from six Spanish centers were included (March 2004 to June 2005) with histological/cytological diagnosis of locally advanced rectal cancer, age between 18 and 80 years, ECOG 0-2, adequate bone marrow, renal and hepatic functions. Prior chemotherapy/radiotherapy was not allowed. Preoperative treatment was capecitabine 825 mg/m(2) bid concomitant to radiotherapy (45 + 5.4 Gy boost over 5.5 weeks). Surgery was performed 4-8 weeks after completion of chemoradiotherapy.

RESULTS

Fifty-eight patients were enrolled in this study: 60.3 % males, median age of 64.5 (30.9-78.7) years, 28.6 % with ECOG 0 and 71.4 % with ECOG 1. Median distance of tumor from the anal verge was 7 (1-12) cm. Fifty-two (89.6. %) patients completed preoperative chemoradiotherapy. Primary tumor and node downstaging occurred in 61.1 and 69.6 % of patients, respectively. Surgery was performed in 55 patients (94.8 %): 80 % had negative lymph nodes and 72.7 % underwent sphincter-preserving procedures. A pathologic complete response was observed in 10.5 % (95 % CI 2.5-18.5) of the patients. Main grade I-II toxicities were leucopenia (43.1 %), neutropenia (24.1 %), anemia (36.2 %), diarrhea (32.8 %) and skin disorders (5.1 %), from which diarrhea (6.9 %), leucopenia (1.7 %) and skin disorders (1.7 %) reached grade III. There were no grade IV toxicities.

CONCLUSIONS

Preoperative capecitabine-based chemoradiation is a well-tolerated and effective neoadjuvant treatment for locally advanced rectal cancer that achieves encouraging rates of tumor downstaging.

Toward the non-surgical management of locally advanced rectal cancer

Neoadjuvant short-course radiotherapy and long-course chemoradiation (CRT) reduce local recurrence rates when compared to surgery alone and remain widely accepted as standard of care for patients with locally advanced rectal cancer. However, surgery is not without complications and a non-surgical approach in carefully selected patients warrants evaluation. A pathological complete response to CRT is associated with a significant improvement in survival and it has been suggested that a longer time interval between the completion of CRT and surgery increases tumor downstaging. Intensification of neoadjuvant treatment regimens to increase tumor downstaging has been evaluated in a number of clinical trials and more recently the introduction of neoadjuvant chemotherapy prior to CRT has demonstrated high rates of radiological tumor regression. Careful selection of patients using high-resolution MRI may allow a non-surgical approach in a subgroup of patients achieving a complete response to neoadjuvant therapies after an adequate time period. Clearly this needs prospective evaluation within a clinical trial setting, incorporating modern imaging techniques, and tissue biomarkers to allow accurate prediction and assessment of response.

Radiation dose-response model for locally advanced rectal cancer after preoperative chemoradiation therapy

PURPOSE

Preoperative chemoradiation therapy (CRT) is part of the standard treatment of locally advanced rectal cancers. Tumor regression at the time of operation is desirable, but not much is known about the relationship between radiation dose and tumor regression. In the present study we estimated radiation dose-response curves for various grades of tumor regression after preoperative CRT.

METHODS AND MATERIALS

A total of 222 patients, treated with consistent chemotherapy and radiation therapy techniques, were considered for the analysis. Radiation therapy consisted of a combination of external-beam radiation therapy and brachytherapy. Response at the time of operation was evaluated from the histopathologic specimen and graded on a 5-point scale (TRG1-5). The probability of achieving complete, major, and partial response was analyzed by ordinal logistic regression, and the effect of including clinical parameters in the model was examined. The radiation dose-response relationship for a specific grade of histopathologic tumor regression was parameterized in terms of the dose required for 50% response, D50,i, and the normalized dose-response gradient, γ50,i.

RESULTS

A highly significant dose-response relationship was found (P=.002). For complete response (TRG1), the dose-response parameters were D50,TRG1=92.0 Gy (95% confidence interval [CI] 79.3-144.9 Gy), γ50,TRG1=0.982 (CI 0.533-1.429), and for major response (TRG1-2) D50,TRG1&2=72.1 Gy (CI 65.3-94.0 Gy), γ50,TRG1&2=0.770 (CI 0.338-1.201). Tumor size and N category both had a significant effect on the dose-response relationships.

CONCLUSIONS

This study demonstrated a significant dose-response relationship for tumor regression after preoperative CRT for locally advanced rectal cancer for tumor dose levels in the range of 50.4-70 Gy, which is higher than the dose range usually considered.

Histologic grading of the extent of residual carcinoma following neoadjuvant chemoradiation in pancreatic ductal adenocarcinoma: a predictor for patient outcome

BACKGROUND

Several grading schemes for the extent of residual tumor in posttreatment pancreaticoduodenectomy (PD) specimens have been proposed. However, the prognostic significance of these grading schemes is unknown.

METHODS

Histopathologic slides of 223 cases who received neoadjuvant chemoradiation and PD were reviewed. The extent of residual tumor was graded using both the College of American Pathologists (CAP) and the Evans grading systems. The grading results were correlated with clinicopathological parameters and survival.

RESULTS

Among the 223 patients, 6 patients (2.7%) showed pathologic complete response (pCR; CAP grade 0 or Evans grade IV), 36 cases (16.1%) had minimal residual tumor (CAP grade 1 or Evans grade III), 124 cases (55.6%) had moderate response (CAP grade 2 or Evans grade IIb), and 57 cases (25.6%) had poor response (CAP grade 3, where 18 had Evans grade I and 39 had Evans grade IIa response). Patients with pCR or minimal residual tumor (response group 1) had better survival rates than those with moderate and poor response (response group 2). Response group 1 patients had lower posttherapy tumor and American Joint Committee on Cancer stages and lower rates of lymph node metastasis, positive resection margin, and recurrence and/or metastasis. Grading the extent of residual tumor is an independent prognostic factor for overall survival in multivariate analysis.

CONCLUSIONS

pCR or minimal residual tumor in posttreatment PD specimens correlate with better survival in patients with pancreatic ductal adenocarcinoma who received neoadjuvant therapy and PD. Histologic grading of the extent of residual tumor in PD specimen is an important prognostic factor in patients with pancreatic ductal adenocarcinoma who received neoadjuvant therapies.

Concurrent chemoradiation of metastases with capecitabine and oxaliplatin and 3D-CRT in patients with oligometastatic colorectal cancer: results of a phase I study

BACKGROUND

Local control appears to be an important treatment aim in patients with limited metastases (oligometastases) of colorectal cancer (CRC). Those patients show a favourable prognosis, if--in addition to the local effective treatment--an occurrence of new metastases may also be postponed by effective systemic therapy. The purpose of this dose escalation phase I study was to establish the efficacy of local radiotherapy (RT) of oligometastatic CRC with a concurrent standard chemotherapy regimen.

METHODS

Patients with first-, second- or third-line therapy of oligometastatic CRC (1-3 metastases or local recurrence plus max. 2 metastases) received capecitabine (825 mg/m²/d BID d 1-14; 22-35) and oxaliplatin (50 mg/m² d 1, 8, 22, 29). 3D-conformal RT of all metastatic lesions was delivered in 2.0 Gy up to 36 Gy to 50 Gy (3 dose levels). Primary endpoint was the maximal tolerable dose (MTD) of RT defined as the level at which two or more of six patients experienced dose-limiting toxicity (DLT).

RESULTS

Between 09/2004 and 08/2007, 9 patients (7 male, 2 female, 50-74 years) were enrolled, 6 patients treated at dose level 1 (36 Gy), 3 patients at dose level 2 (44 Gy). 1 patient from the first cohort experienced DLT (oxaliplatin-related hypersensitivity reaction). No radiation-induced DLT occurred. 6/9 patients achieved objective response (partial remission). One year after initiation, all patients were alive, 6 patients survived (16 to 54 months) patients died of tumor progression (14 to 23 months). The phase II part of the trial had to be closed due to recruitment failure.

CONCLUSIONS

Local 3D-CRT to metastatic lesions in addition to standard chemotherapy was feasible, DLT was not documented. 3/9 patients survived for a period of 3.5 to 4.4 years (time at the last evaluation). Radiotherapy of metastatic lesions should be incorporated into subsequent trials.

Current status of intensified neo-adjuvant systemic therapy in locally advanced rectal cancer

The addition of 5-fluorouracil (5-FU) or its prodrug capecitabine to radiotherapy (RT) is a standard approach in the neo-adjuvant treatment of patients with rectal tumors extending beyond the muscularis propria (stage II) and/or with clinical evidence of regional lymph node metastases (stage III). According to European randomized trials, the combined treatment modality resulted in favorable local control rates as compared with radiotherapy (RT) alone, but no improvement was found regarding the occurrence of distant metastases or overall survival. In an effort to further enhance the response rates and to decrease the high incidence of distant metastases in locally advanced rectal cancer patients, the addition of other chemotherapeutical drugs and biologic agents as radiation sensitizers to neo-adjuvant 5-FU based chemoradiotherapy (CRT) has been recently investigated. The role of those agents is however questionable as first results from phase III data do not show improvement on pathologic complete remission and circumferential resection margin negative resection rates as compared to 5-FU based CRT, nevertheless an increased toxicity.

Preoperative chemoradiotherapy and postoperative chemotherapy with fluorouracil and oxaliplatin versus fluorouracil alone in locally advanced rectal cancer: initial results of the German CAO/ARO/AIO-04 randomised phase 3 trial

BACKGROUND

Preoperative chemoradiotherapy, total mesorectal excision surgery, and adjuvant chemotherapy with fluorouracil is the standard combined modality treatment for rectal cancer. With the aim of improving disease-free survival (DFS), this phase 3 study (CAO/ARO/AIO-04) integrated oxaliplatin into standard treatment.

METHODS

This was a multicentre, open-label, randomised, phase 3 study in patients with histologically proven carcinoma of the rectum with clinically staged T3-4 or any node-positive disease. Between July 25, 2006, and Feb 26, 2010, patients were randomly assigned to two groups: a control group receiving standard fluorouracil-based combined modality treatment, consisting of preoperative radiotherapy of 50·4 Gy plus infusional fluorouracil (1000 mg/m(2) days 1-5 and 29-33), followed by surgery and four cycles of bolus fluorouracil (500 mg/m(2) days 1-5 and 29; fluorouracil group); and an experimental group receiving preoperative radiotherapy of 50·4 Gy plus infusional fluorouracil (250 mg/m(2) days 1-14 and 22-35) and oxaliplatin (50 mg/m(2) days 1, 8, 22, and 29), followed by surgery and eight cycles of adjuvant chemotherapy with oxaliplatin (100 mg/m(2) days 1 and 15), leucovorin (400 mg/m(2) days 1 and 15), and infusional fluorouracil (2400 mg/m(2) days 1-2 and 15-16; fluorouracil plus oxaliplatin group). Randomisation was done with computer-generated block-randomisation codes stratified by centre, clinical T category (cT1-4 vs cT4), and clinical N category (cN0 vs cN1-2) without masking. DFS is the primary endpoint. Secondary endpoints, including toxicity, compliance, and histopathological response are reported here. Safety and compliance analyses included patients as treated, efficacy endpoints were analysed according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov, number NCT00349076.

FINDINGS

Of the 1265 patients initially enrolled, 1236 were evaluable (613 in the fluorouracil plus oxaliplatin group and 623 in the fluorouracil group). Preoperative grade 3-4 toxic effects occurred in 140 (23%) of 606 patients who actually received fluorouracil and oxaliplatin during chemoradiotherapy and in 127 (20%) of 624 patients who actually received fluorouracil chemoradiotherapy. Grade 3-4 diarrhoea was more common in those who received fluorouracil and oxaliplatin during chemoradiotherapy than in those who received fluorouracil during chemoradiotherapy (73 patients [12%] vs 52 patients [8%]), as was grade 3-4 nausea or vomiting (23 [4%] vs nine [1%]). 516 (85%) of the 606 patients who received fluorouracil and oxaliplatin-based chemoradiotherapy had the full dose of chemotherapy, and 571 (94%) had the full dose of radiotherapy; as did 495 (79%) and 601 (96%) of 624 patients who received fluorouracil-based chemoradiotherapy, respectively. A pathological complete response was achieved in 103 (17%) of 591 patients who underwent surgery in the fluorouracil and oxaliplatin group and in 81 (13%) of 606 patients who underwent surgery in the fluorouracil group (odds ratio 1·40, 95% CI 1·02-1·92; p=0·038). In the fluorouracil and oxaliplatin group, 352 (81%) of 435 patients who began adjuvant chemotherapy completed all cycles (with or without dose reduction), as did 386 (83%) of 463 patients in the fluorouracil group.

INTERPRETATION

Inclusion of oxaliplatin into modified fluorouracil-based combined modality treatment was feasible and led to more patients achieving a pathological complete response than did standard treatment. Longer follow-up is needed to assess DFS.

FUNDING

German Cancer Aid (Deutsche Krebshilfe).

Multidisciplinary treatment of patients with rectal cancer: Development during the past decades and plans for the future

In rectal cancer treatment, both the local primary and the regional and systemic tumour cell deposits must be taken care of in order to improve survival. The three main treatments, surgery, radiotherapy, and chemotherapy, each with their own advantages and limitations, must then be combined to improve results. Several large randomized trials have shown that combinations of the modalities have markedly reduced the loco-regional recurrences, but have not yet had any major influence on overall survival. The best integration of the weakest modality, to date the drugs (conventional cytotoxics and biologicals), is not known. A new generation of trials exploring the best sequence of treatments is required. Furthermore, treatment of rectal cancer is administered to populations of individuals, based upon clinical factors and imaging, and can presently not be further individualized. There is an urgent need to develop response predictors.