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

Role of combined-modality therapy in the management of locally advanced rectal cancer

The majority of patients with nonmetastatic rectal cancer are candidates for an aggressive multimodality approach with curative intent. Preoperative staging is critical in determining which patients should be offered neoadjuvant therapy. Available staging tools include digital rectal examination, transrectal ultrasound, computed tomography, positron-emission tomography, and magnetic resonance imaging scans. Magnetic resonance imaging has emerged as the most accurate staging modality in experienced centers. Multidisciplinary preoperative patient evaluation, better staging techniques, neoadjuvant chemoradiation, acceptance of shorter distal rectal margins, and transanal excision of T1 N0 rectal tumors in close proximity to the anal sphincter have resulted in decreased rates of abdominoperineal resections. Total mesorectal excision has been adopted as the standard surgical approach because of a reduction in rates of pelvic relapse. Preoperative and postoperative radiation therapy was shown to decrease the local recurrence rate, but not overall survival, in patients with resectable rectal cancer. The addition of chemotherapy to radiation was consistently shown to improve local control, and in some trials, improved overall survival. Neoadjuvant combined chemotherapy and radiation therapy are superior to adjuvant combined-modality therapy because of higher rates of sphincter preservation, less toxicity, and lower local recurrence rates. For patients with stage II or III disease, neoadjuvant continuous-infusion 5-fluorouracil (5-FU), concurrently with pelvic radiation, followed by postoperative 5-FU-based chemotherapy, remains the standard multimodality approach. Ongoing trials are testing the integration of newer cytotoxic agents such as capecitabine, oxaliplatin, irinotecan, and biologic agents such as cetuximab and bevacizumab to chemoradiation.

MR vs CT imaging: low rectal cancer tumour delineation for three-dimensional conformal radiotherapy

Modern three-dimentional radiotherapy is based upon CT. For rectal cancer, this relies upon target definition on CT, which is not the optimal imaging modality. The major limitation of CT is its low inherent contrast resolution. Targets defined by MRI could facilitate smaller, more accurate, tumour volumes than CT. Our study reviewed imaging and planning data for 10 patients with locally advanced low rectal cancer (defined as < 6 cm from the anal verge on digital examination). Tumour volume and location were compared for sagittal pre-treatment MRI and planning CT. CT consistently overestimated all tumour radiological parameters. Estimates of tumour volume, tumour length and height of proximal tumour from the anal verge were larger on planning CT than on MRI (p < 0.05). Tumour volumes defined on MRI are smaller, shorter and more distal from the anal sphincter than CT-based volumes. For radiotherapy planning, this may result in smaller treatment volumes, which could lead to a reduction in dose to organs at risk and facilitate dose escalation.

Management of rectal cancer: short- vs. long-course preoperative radiation

There is considerable debate on the optimum approach to neoadjuvant therapy in rectal cancer. This review of major published studies of short-course preoperative radiation and the more conventional approach of long-course neoadjuvant chemoradiation was undertaken in an effort to understand the potential advantages and disadvantages of each of these approaches. Studies were evaluated with regard to patient selection, clinical outcomes, and toxicities. Short-course preoperative radiation has shown a clear advantage over surgery alone in reducing local recurrence rates and improving survival of patients with rectal cancer. However, studies using short-course preoperative treatment have included a significant number of early (30%; Stage I/II) and more proximal cancers yet appear to have higher positive margin rates, higher abdominoperineal resection rates, and lower aggregate survival than patients treated with long-course neoadjuvant chemoradiation. Although long-course preoperative chemoradiation is associated with higher rates of reversible acute toxicity, there appears to be more significant and a higher rate of late gastrointestinal toxicity observed in short-course preoperative radiation studies. Patient convenience and lower cost of treatment, however, can be a significant advantage in using a short-course treatment schedule. Selective utilization of either of these approaches should be based on extent of disease and goals of treatment. Patients with distal cancers or more advanced disease (T3/T4) appear to have better outcomes with neoadjuvant chemoradiation, especially where downstaging of disease is critical for more complete surgical resection and sphincter preservation.

Two-marker protein profile predicts poor prognosis in patients with early rectal cancer

The aim of this study was to establish an immunohistochemical protein profile to complement preoperative staging and identify rectal cancer patients at high-risk of adverse outcome. Immunohistochemistry was performed on a tissue microarray including 482 rectal cancers for APAF-1, EphB2, MST1, Ki67, p53, RHAMM, RKIP and CD8⁺ tumour infiltrating lymphocytes (TILs). After resampling of the data and multivariable analysis, the most reproducible markers were combined and prognosis evaluated as stratified by pT and pN status. In multivariable analysis, only positive RHAMM (P<0.001; HR=1.94 (1.44–2.61)) and loss of CD8⁺ TILs (P=0.006; HR=0.63 (0.45–0.88)) were independent prognostic factors. The 5-year cancer-specific survival rate for RHAMM+/TIL− patients was 30% (95% CI 21–40%) compared to 76% (95% CI: 66–84%) for RHAMM−/TIL+ patients (P<0.001). The 5-year cancer-specific survival of T1/T2/RHAMM+/TIL− patients was 48% (20–72%) and significantly worse compared to T3/T4/RHAMM−/TIL+ patients (71% 95% CI 56–82%); P=0.039). Stratifying by nodal status, only N+/RHAMM+/TIL− patients demonstrated a significantly worse prognosis than N0/RHAMM+/TIL− patients (P=0.005). Loss of CD8⁺ TILs was predictive of local recurrence in RHAMM+ tumours (P=0.009) only. RHAMM and CD8⁺ TILs may assist in identifying early stage rectal cancer patients facing a particularly poor prognosis and who may derive a benefit from preoperative therapy.

Pre-operative chemoradiotherapy with UFT and Leucovorin in patients with advanced rectal cancer: a phase II study

PURPOSE

The aim this study was to determine the pathologic complete response (pCR) rate defined as tumor regression grade 1 (TRG1) and toxicity profile of the combination of high-dose pre-operative radiotherapy and simultaneous UFT/leucovorin (LV) in patients with locally advanced rectal cancer.

MATERIALS/METHODS

Eligibility included biopsy proven rectal adenocarcinoma; T3-T4 N0-N2; performance status < 2 (ECOG) and adequate blood, hepatic and renal function. Treatment consisted of radiotherapy 54 Gy at 1.8 Gy/day and UFT 300 mg/m(2)/day and LV 60 mg/day, given simultaneously daily for 6 weeks. Surgery was performed within 4-6 weeks period after chemoradiotherapy. Patients who did not achieve TGR1 were to receive 4 cycles of adjuvant UFT/LV on days 1-28, every 5 weeks.

RESULTS

Sixty-eight patients were included. All but one received full dose of radiation and 62 had the total planned pre-operative UFT/LV dose. Grade 3 toxicities were diarrhea 7% and proctitis 3%. Complete resection was achieved in 62 patients (91%). Tumor regression grade 1 (TRG1) was seen in 11 patients (16%). Forty-eight patients received adjuvant UFT/LV. Grade 3 toxicity during adjuvant UFT/LV included diarrhea 12%, asthenia 4%, neutropenia 2%, and hand-foot syndrome 2%. The 3-year disease-free survival was 71%.

CONCLUSIONS

Simultaneous high-dose pre-operative localized radiation therapy concurrent with UFT/LV is feasible and has a low toxicity profile. This schedule is highly effective and merits further investigation.

Performing nondiagnostic research biopsies in irradiated tissue: a review of scientific, clinical, and ethical considerations

PURPOSE

Recent development of drugs that target specific pathways in tumors has increased scientific interest in studying drug effects on tumor tissue. As a result, biopsies have become an important part of many early-phase clinical trials. Performing nondiagnostic tumor biopsies raises technical and ethical concerns mostly related to the use of a potentially harmful procedure with no potential benefit to the patient. This issue is complicated by uncertainty about whether performing biopsies in irradiated fields adds significant risk. This article reviews the clinical, scientific, and ethical considerations involved in performing nondiagnostic tumor biopsies in competent adults for research purposes, with a focus on biopsies performed in the setting of therapeutic irradiation.

METHODS

Clinical trials that performed biopsies during or within 4 months of the completion of radiotherapy were identified with a literature review.

RESULTS

Twenty-nine studies with 2,160 patients were identified. Sixteen of 29 studies reported adverse events (AEs) but did not report active evaluation for biopsy complications. Ten studies did not mention AEs within the study report. At least three studies actively evaluated patients for biopsy complications. Taking this into consideration, 17 (>1%) of 2,160 patients were reported to have biopsy complications, although reporting of AEs was suboptimal in most studies.

CONCLUSION

Limited data suggest that biopsies can be performed in irradiated tissues without clinically significant excess risk. Ongoing and future trials including nondiagnostic research biopsies should record and report AEs related to this procedure to provide additional data on safety and toxicity.

A randomised phase III trial of adjuvant radio-chemotherapy comparing Irinotecan, 5FU and Leucovorin to 5FU and Leucovorin in patients with rectal cancer: a Hellenic Cooperative Oncology Group Study

The primary objective was to compare the 3-year survival of rectal cancer patients randomised postoperatively to irinotecan (IRI), Leucovorin (LV) and bolus 5-fluorouracil (5FU) or LV-bolus 5FU with radiotherapy. Secondary objectives included disease-free survival, local relapse and toxicity. The study included 321 eligible patients. The treatment consisted of weekly administration of IRI 80 mg/m(2) intravenously (IV), LV 200 mg/m(2) and 5FU 450 mg/m(2) bolus (arm A) versus LV 200 mg/m(2) and 5FU 450 mg/m(2) IV bolus (arm B). One cycle included four infusions and treatment was continued for a total of six cycles. The first cycle was followed by pelvic irradiation plus 5FU. There were no differences between the arms in 3-year overall, disease-free and local relapse-free survival. Grades 3 and 4 toxicity was similar in both the arms with the exception of leucopaenia, neutropaenia and alopecia, which were higher in the IRI arm. IRI added to adjuvant radiochemotherapy with LV and bolus 5FU was not shown to improve survival, whereas the incidence of severe leucopaenia was significantly higher in the IRI arm.

Preoperative capecitabine and accelerated intensity-modulated radiotherapy in locally advanced rectal cancer: a phase II trial

OBJECTIVES

A prospective phase II trial was conducted to evaluate the feasibility, safety, and pathologic response rate of preoperative capecitabine and accelerated synchronous integrated boost (SIB) intensity-modulated radiotherapy (IMRT) in patients with locally advanced rectal cancer.

METHODS

Consenting operable patients with stage II or III adenocarcinoma of the rectum received capecitabine (825 mg/m2 PO BID, 5 days/wk x 5 weeks) and SIB-IMRT delivering 55 Gy (2.2 Gy/fraction) to the gross tumor while simultaneously delivering 45 Gy (1.8 Gy/fraction) to the regional lymph nodes and areas at risk for harboring microscopic disease. Total mesorectal excision followed 6 weeks later. A single pathologist analyzed the resected tumor's TNM stage and Mandard regression/response scores. The primary end point was pathologic complete response (pCR) rate.

RESULTS

Ten subjects were enrolled, 2 of which were ineligible (1 screening failure and 1 unrelated cerebrovascular accident occurring early in treatment). The remaining 8 patients were evaluable. All 8 completed chemoradiation with strict compliance to the protocol schedule and then went on to surgical resection. At a median follow-up of 26 months (range, 15-40), all patients were alive without evidence of recurrent disease. The crude pCR rate was 38% with 50% achieving down-staging. Of 3 patients who had tumors within 5 cm of the anal verge, 2 underwent sphincter-sparing procedures. Grade 4 diarrhea occurred in 1 of 8 (13%) patients. The remaining toxicities were grade 1 or 2.

CONCLUSIONS

Preoperative chemoradiation with capecitabine and SIB-IMRT is well tolerated and results in an encouraging pCR rate for patients with locally advanced rectal cancer.

Evidence and research in rectal cancer

The main evidences of epidemiology, diagnostic imaging, pathology, surgery, radiotherapy, chemotherapy and follow-up are reviewed to optimize the routine treatment of rectal cancer according to a multidisciplinary approach. This paper reports on the knowledge shared between different specialists involved in the design and management of the multidisciplinary ESTRO Teaching Course on Rectal Cancer. The scenario of ongoing research is also addressed. In this time of changing treatments, it clearly appears that a common standard for large heterogeneous patient groups have to be substituted by more individualised therapies based on clinical-pathological features and very soon on molecular and genetic markers. Only trained multidisciplinary teams can face this new challenge and tailor the treatments according to the best scientific evidence for each patient.

Current options for the management of rectal cancer

Patients diagnosed with rectal cancer should undergo locoregional staging with transrectal endoscopic ultrasound (EUS) or surface coil array MRI of the pelvis if that technique is available. Patients thought to have more than very early stage (T1 or T2) disease should undergo abdominal imaging as well by CT or MRI, and chest imaging with either CXR or preferably CT. The care of rectal cancer patients should be coordinated amongst an experienced multidisciplinary team to maximize the chance of cure and to minimize both local recurrence and complications of therapy. For patients with very early stage disease (T1N0 or T2N0), local resection with or without chemoradiation may be adequate therapy, but these patients must be selected carefully and should be without any poor prognostic factors. For the majority of patients with T3N0 or greater rectal cancer, standard therapy consists of neoadjuvant continuous 5-FU and radiation followed by surgery and further chemotherapy (either with 5-FU, capecitabine, or FOLFOX). The use of capecitabine, irinotecan, and oxaliplatin during radiotherapy shows promise, but remains investigational pending results of phase III studies. Neoadjuvant therapy is preferred because it decreases local recurrence and appears to result in improved postoperative bowel function in comparison with postoperative therapy. Select patients with high (>10 cm from the anal verge) uT3N0 tumors may be at sufficiently low risk of local recurrence to justify omission of radiotherapy. Patients who experience pathologic complete response to radiotherapy should still receive postoperative adjuvant chemotherapy to reduce systemic recurrence risk until data demonstrate that this is not necessary. Patients with stage IV rectal cancer may still require local therapy with radiation, surgery, or both; however, care should be taken in these patients that chemotherapy is not excessively delayed as this is the one modality in this case that can result in improved survival.

Emerging role of intensity-modulated radiation therapy in anorectal cancer

Although radiation therapy has an established role to play in the management of rectal and anal tumors, there are often treatment-related morbidities that negatively impact on patients. There is a long-standing interest in radiation oncology on maximizing treatment efficacy while minimizing treatment-related toxicities, which can be pronounced in the treatment of pelvic malignancies. Intensity-modulated radiation therapy is a recently introduced technology that has the potential to increase the efficacy:toxicity ratio. It has been implemented in the treatment of prostate and head and neck tumors with success. This article reviews the rationale for its use in treating anorectal tumors and discusses early clinical data supporting its continued investigation.

Prognostic value of pathologic complete response after neoadjuvant therapy in locally advanced rectal cancer: long-term analysis of 566 ypCR patients

PURPOSE

In the literature, a favorable prognosis was observed for complete pathologic response after preoperative therapy (ypCR) in patients with locally advanced rectal cancer. The aim of this study is to verify whether ypCR predicts a favorable outcome in a large series of patients.

METHODS AND MATERIALS

The Gastro-Intestinal Working Group of the Italian Association of Radiation Oncology collected clinical data for 566 patients with ypCR (ypT0N0) after neoadjuvant therapy. Eligibility criteria included locally advanced rectal cancer with no evidence of metastases at the time of diagnosis, evidence of ypCR after preoperative radiotherapy +/- chemotherapy (CT).

RESULTS

Median radiation dose was 50 Gy. A total of 527 patients (93%) received one of 12 different neoadjuvant CT schedules. Sphincter preservation, anteroposterior resection, and endoscopic surgery were performed in 73%, 22%, and 5% of patients, respectively. Adjuvant CT was administered to 22% of patients. Median follow-up was 46.4 months. Locoregional recurrence occurred in 7 patients (1.6%). Distant metastases occurred in 49 patients (8.9%). Overall, 5-year rates of disease-free survival, overall survival, and cancer-specific survival were 85%, 90%, and 94%, respectively. In multivariate analysis, only age and clinical stage statistically correlated with survival outcome. Adjuvant CT was still of borderline significance (worse for adjuvant CT). No relation was found between survival and neoadjuvant CT schedules.

CONCLUSION

A ypCR after neoadjuvant therapy identified a favorable group of patients, even in this large series of 566 patients collected in 61 centers. Locoregional recurrence occurred only in 1.6% patients.

Irinotecan+5-fluorouracil with concomitant pre-operative radiotherapy in locally advanced non-resectable rectal cancer: a phase I/II study

In the UK, 10% of patients diagnosed with rectal cancer have inoperable disease at presentation. This study ascertained whether the resectability rate of inoperable locally advanced rectal cancer was improved by administration of intravenous irinotecan, 5-fluorouracil (5-FU) and pelvic radiotherapy. During phase I of the trial (n=12), the dose of irinotecan was escalated in three-patient cohorts from 50 mg m⁻² to 60 mg m⁻² to 70 mg m⁻² to identify the maximum tolerated dose (60 mg m⁻²). In phase II, 31 patients with non-resectable disease received 45 Gy radiotherapy and 5-FU infusions (200 mg m⁻² per day) for 5 weeks. Irinotecan (60 mg m⁻²) was given on days 1, 8, 15 and 22. After treatment, patients were operated on if possible. Thirty patients completed the protocol, 28 underwent surgery. Before surgery, MRI restaging of 24 patients showed that 19 (79%) had a reduction in tumour stage after treatment (seven complete clinical response and 12 partial). Of 27 patients followed up after surgery, 22 (81%) had clear circumferential resection margins. Disease-free and overall survival estimates at 3 years were 65 and 90%, respectively. The regimen was well tolerated. Irinotecan, 5-FU and radiotherapy results in tumour downgrading, allowing resection of previously inoperable tumour with acceptable toxicity.

Late adverse effects of radiation therapy for rectal cancer - a systematic overview

PURPOSE

The use of radiation therapy (RT) together with improvement in the surgical treatment of rectal cancer improves survival and reduces the risk for local recurrences. Despite these benefits, the adverse effects of radiation therapy limit its use. The aim of this review was to present a comprehensive overview of published studies on late adverse effects related to the RT for rectal cancer.

METHODS

Meta-analyses, reviews, randomised clinical trials, cohort studies and case-control studies on late adverse effects, due to pre- or postoperative radiation therapy and chemo-radiotherapy for rectal cancer, were systematically searched. Most information was obtained from the randomised trials, especially those comparing preoperative short-course 5 x 5 Gy radiation therapy with surgery alone.

RESULTS

The late adverse effects due to RT were bowel obstructions; bowel dysfunction presented as faecal incontinence to gas, loose or solid stools, evacuation problems or urgency; and sexual dysfunction. However, fewer late adverse effects were reported in recent studies, which generally used smaller irradiated volumes and better irradiation techniques; although, one study revealed an increased risk for secondary cancers in irradiated patients.

CONCLUSIONS

These results stress the importance of careful patient selection for RT for rectal cancer. Improvements in the radiation technique should further be developed and the long-term follow-up of the randomised trials is the most important source of information on late adverse effects and should therefore be continued.

Tumor response to neoadjuvant chemoradiation in rectal cancer: predictor for surgical morbidity?

BACKGROUND

Increasing the rate of pathological complete remissions after neoadjuvant chemoradiation of rectal cancer has become a strategy to further improve the long-term oncological outcome of patients. This report evaluates the influence of preoperative intensified radiochemotherapy on the rate and outcome of surgical complications.

MATERIALS AND METHODS

Patients with primary rectal cancer at stages cT3/4cNx or N+ without metastasis were preoperatively treated either with capecitabine and irinotecan or with capecitabine, irinotecan and ceutximab with a concurrent radiation (50.4 Gy). Surgery was scheduled 4-7 weeks after completion of the chemoradiation. Perioperative complications were prospectively documented during the patient's hospital stay.

RESULTS

Fifty-nine patients (median age 60; male/female: 46/13) undergoing surgery at a single center were analysed. The median distance of the tumour from the dentate line was 5 cm. The operations performed were low anterior resection (n=45), Hartmann's procedure (n=4) and abdominoperineal resection (n=10). Total mesorectal excision with R0-resection was accomplished in all but one patients. Histopathological regression was described in four grades (0-3) as defined by the Japanese Society for Cancer of the Colon and Rectum. Tumors were called major responsive when assigned to the regression grades 3 or 2, and minor or nonresponsive at regression grades 1 or 0. In total, 33 patients (55.9%) had a regression grade 2 or 3. Among them, 12 patients showed a pathological complete response without any residual cancer cell (20.3%). Seven out of 45 patients (15.5%) with sphincter-preserving surgery suffered from suture breakdown; they all had previously shown a major response of the resected tumor. Two of them died during the hospital stay.

CONCLUSIONS

While in general, patients undergoing neoadjuvant intensified treatment suffer from a slight increase in surgical complications, this is markedly enhanced in patients with good treatment responses. Our results underline the oncological benefit of intensified neoadjuvant chemoradiation, but the severity of complications in low rectal anastomosis of patients with good response after neoadjuvant therapy should alert surgeons and oncologists.

Chemoradiotherapy for rectal cancer: an updated analysis of factors affecting pathological response

AIMS

With the aim of improving locoregional control, the use of preoperative chemoradiotherapy (CRT) for rectal cancer has increased. A pathological complete response (pCR) is often used as a surrogate marker for the efficacy of different CRT schedules. By analysing factors affecting pCR, this analysis aims to guide the development of future trials.

MATERIALS AND METHODS

Searches of Medline, EMBASE and the electronic American Society of Clinical Oncology abstract databases were carried out to identify prospective phase II and phase III trials using preoperative CRT to treat rectal cancer. Trials were eligible for inclusion if they defined: the CRT drugs, the radiation dose and the pCR rate. Phase I patients were excluded from the analysis. A multivariate analysis examined the effect of the above variables on the pCR rate and in addition the use of neoadjuvant chemotherapy, the type of publication (peer reviewed vs abstract), the year of publication and whether the cancers were stated to be inoperable, fixed or threatening the circumferential resection margin were included. The method of analysis used was weighted linear modelling of the pCR rate.

RESULTS

Sixty-four phase II and seven phase III trials were identified including a total of 4732 patients. Statistically significant factors associated with pCR were the use of two drugs, the method of fluoropyrimidine administration (with continuous intravenous 5-fluorouracil being the most effective) and a higher radiotherapy dose. Although the use of two drugs was associated with a higher rate of pCR, no single schedule seemed to be more effective. None of the other factors analysed significantly influenced pCR.

CONCLUSIONS

A higher rate of pCR is seen in studies using two drugs, infusional 5-fluorouracil and a radiotherapy dose of 45 Gy and above.

Preoperative Chemoradiotherapy for Rectal Cancer: Randomized Trial Comparing Oral Uracil and Tegafur and Oral Leucovorin Vs. Intravenous 5-Fluorouracil and Leucovorin

PURPOSE

To compare, in a randomized trial, 5-fluorouracil (FU) plus leucovorin (LV) (FU+LV) vs. oral uracil and tegafur (UFT) plus LV (UFT+LV) given concomitantly with preoperative irradiation in patients with cT3-4 or N+ rectal cancer.

METHODS AND MATERIALS

A total of 155 patients were entered onto the trial. Patients received pelvic radiotherapy (4500-5,040 cGy in 5 to 6 weeks) and chemotherapy consisting of two 5-day courses of 20 mg/m(2)/d LV and 350 mg/m(2)/d FU in the first and fifth weeks of radiotherapy (77 patients) or one course of 25 mg/d oral LV and 300 mg/m(2)/d UFT for 4 weeks beginning in the second week of radiotherapy (78 patients). The primary endpoints were pathologic complete response (pCR) and resectability rate. Secondary endpoints included downstaging rate, toxicity, and survival.

RESULTS

Grade 3-5 acute hematologic toxicity occurred only with FU+LV (leukopenia 9%; p = 0.02). There were no differences in resectability rates (92.1% vs. 93.4%; p = 0.82). The pCR rate was 13.2% in both arms. Tumor downstaging was more frequent with UFT+LV (59.2% vs. 43.3%; p = 0.04). Three-year overall survival was 87% with FU+LV and 74% with UFT+LV (p = 0.37). The 3-year cumulative incidences of local recurrence were 7.5% and 8.9%, respectively (p = 0.619; relative risk, 1.46; 95% confidence interval 0.32-6.55).

CONCLUSION

Although this study lacked statistical power to exclude clinically significant differences between both groups, the outcome of patients treated with UFT+LV did not differ significantly from that of patients treated with FU+LV, and hematologic toxicity was significantly lower in the experimental arm.

Rectal cancer treatment: Improving the picture

Multidisciplinary approach for rectal cancer treatment is currently well defined. Nevertheless, new and promising advances are enriching the portrait. Since the US NIH Consensus in the early 90’s some new characters have been added. A bird’s-eye view along the last decade shows the main milestones in the development of rectal cancer treatment protocols. New drugs, in combination with radiotherapy are being tested to increase response and tumor control outcomes. However, therapeutic intensity is often associated with toxicity. Thus, innovative strategies are needed to create a better-balanced therapeutic ratio. Molecular targeted therapies and improved technology for delivering radiotherapy respond to the need for accuracy and precision in rectal cancer treatment.

Randomized, multicenter, phase IIb study of preoperative chemoradiotherapy in T3 mid-distal rectal cancer: raltitrexed + oxaliplatin + radiotherapy versus cisplatin + 5-fluorouracil + radiotherapy

PURPOSE

To prospectively compare the rates of pathologic response, acute toxicity, and sphincter preservation with two different schedules of preoperative chemoradiotherapy in patients with cT3 mid-distal rectal cancer.

METHODS AND MATERIALS

Patients with cT3 and/or N+ resectable rectal carcinoma were randomized to receive one of the two following chemoradiotherapy regimens: cisplatin, 5-fluorouracil, and radiotherapy (PLAFUR) or raltitrexed, oxaliplatin, and radiotherapy (TOMOX-RT). For PLAFUR, cisplatin (60 mg/m(2)) was given on Days 1 and 29, with a prolonged infusion of 5-fluorouracil (1,000 mg/m(2)) on Days 1-4 and 29-32, plus concurrent radiotherapy (50.4 Gy in 1.8-Gy fractions daily). For TOMOX-RT, raltitrexed (3 mg/m(2)) and oxaliplatin (130 mg/m(2)) was given on Days 1, 19, and 38 with the same radiotherapy regimen as used for PLAFUR. Surgery was performed 6-8 weeks after completion of chemoradiotherapy. All pathologic specimens were reviewed by a designated expert pathologist. The primary endpoint of this study was pathologic tumor downstaging (defined as tumor regression grade 1-2). Secondary endpoints included the incidence of ypT0, clinical tumor downstaging, sphincter-saving surgery, and acute treatment-related toxicity.

RESULTS

Between 2002 and 2005, 164 patients were accrued in 10 Italian centers, 83 patients in the PLAFUR arm and 81 in the TOMOX-RT arm. Overall, tumor regression grade 1-2 was observed in 76 patients (46.4%) and ypT0 in 49 (29.9%). The tumor regression grade 1-2 rate was 41.0% vs. 51.9% (p = 0.162) and the ypT0 rate was 24.1% vs. 35.8% (p = 0.102) for the PLAFUR vs. TOMOX-RT arm, respectively. The overall rate of tumor regression grade 1 and ypN+ was 4.6%. The occurrence of ypT downstaging was significantly greater in the TOMOX-RT arm (p = 0.035). Grade 3-4 acute toxicity occurred in 19 patients (11.6%): 7.1% in the PLAFUR arm vs. 16.4% in the TOMOX-RT arm. Sphincter-saving surgery was performed in 143 patients (87.2%) overall: 87.9% in the PLAFUR arm and 86.4% in the TOMOX-RT arm.

CONCLUSIONS

Compared with the PLAFUR regimen, TOMOX-RT achieved a greater incidence of downstaging but was associated with a correspondingly greater rate of acute Grade 3+ toxicity. With longer follow-up, the local control and survival rates might offer additional guidance as to the choice of regimen.

Non-operative treatment after neoadjuvant chemoradiotherapy for rectal cancer

The past decade has seen pronounced changes in the treatment of locally advanced rectal cancer. Historically, the standard of care involved surgery followed by adjuvant radiotherapy or chemoradiotherapy. More recently, the emergence of neo-adjuvant chemoradiotherapy has fundamentally changed the management of patients with locally advanced disease. In clinical trials, pathological complete responses of up to 25% have raised the question as to whether surgery can be avoided in a select cohort of patients. A trial of omission of surgery for selected patients with complete response after preoperative chemoradiotherapy has shown favourable long-term results. In this article, we outline emerging factors for achieving pathological complete response, non-operative strategies to date, methods for prediction of response to chemoradiotherapy, and future directions with the addition of MRI as a radiological guide to complete response.

High dose rate endorectal brachytherapy as a neoadjuvant treatment for patients with resectable rectal cancer

In the era of total mesorectal surgery, the issue of radiation toxicity is raised. A novel endocavitary brachytherapy technique was tested as a neoadjuvant treatment for patients with resectable rectal cancer. The objectives of the study were to evaluate the treatment-related toxicity and effects on local recurrence. A dose of 26 Gy was prescribed to the gross tumour volume and intramesorectal deposits seen on magnetic resonance imaging and given over four daily treatments, using the high dose rate delivery system followed by surgery 6-8 weeks later. The study included 93 T3, four T4 and three T2 tumours. Acute proctitis of grade 2 was observed in all patients, but one required transfusion. At a median follow-up time of 60 months, the 5-year actual local recurrence rate was 5%, disease-free survival was 65%, and overall survival was 70%. High dose rate endorectal brachytherapy seems to prevent local recurrence and has a favourable toxicity pattern compared with external beam radiotherapy.

Adjuvant therapy for rectal cancer

Patients with stage II and III rectal cancer benefit from a multidisciplinary approach to treatment. Studies of postoperative adjuvant therapy consistently demonstrate decreases in locoregional recurrence with the use of radiation therapy. The use of postoperative chemotherapy results in improved disease-free survival and overall survival in certain studies. Preoperative radiation therapy decreases locoregional recurrence and in one study demonstrated an improvement in survival. The addition of chemotherapy to preoperative radiation results in improved locoregional control, but not survival. Preoperative chemoradiation is the standard of care for patients with clinical stage II and III rectal cancer in the United States due to improved local recurrence, acute and late toxicity, and sphincter preservation compared with postoperative chemoradiation. Promising approaches include the incorporation of new chemotherapeutic and biologic agents into chemoradiation and adjuvant chemotherapy regimens; new radiation techniques, such as the use of intraoperative radiation therapy and an accelerated concomitant radiation boost; and gene and protein expression profiling, to better predict response to treatment and prognosis.

Mitomycin-C/5-fluorouracil/leucovorin and hyperfractionated radiation therapy for rectal carcinoma: a phase II study with long-term follow-up

PURPOSE

Preoperative chemotherapy followed by surgery and adjuvant chemotherapy is a standard treatment for most patients with rectal cancer. We aimed to determine efficacy and tolerability of preoperative mitomycin, fluorouracil (5-FU), and leucovorin (LV) concurrent with hyperfractionated radiation therapy (RT) followed by surgery and adjuvant chemotherapy.

PATIENTS AND METHODS

Patients with clinical stage II/III disease were treated with mitomycin 10 mg/m(2) on day 1, continuous venous infusion 5-FU 600 mg/m(2) per day for 96 hours, and oral LV 25 mg every 6 hours on days 1-5. All patients received concurrent RT in fractions of 150 cGy twice daily beginning on day 1. Unfixed tumors received 3000 cGy, whereas fixed tumors received a dose of 4500 cGy. Patients then underwent resection and postoperative adjuvant chemotherapy with oral LV and continuous venous infusion 5-FU 600 mg/m(2) per day on days 1-5 on a 28-day cycle for 6 cycles. Primary endpoints were to determine the rate of pathologic response and downstaging, long-term locoregional control, progression-free survival, and overall survival.

RESULTS

Between the years 1993 and 2000, 83 patients were enrolled. Eighteen patients (31%) were downstaged. Six patients (7%) had pathologic complete response. Median follow-up was 62 months with a 5-year overall survival of 71%. Local control rate was 96%. Treatment was well tolerated with stomatitis, diarrhea, and radiation proctitis being the most common toxicities.

CONCLUSION

This regimen is effective in the treatment of rectal carcinoma. The favorable toxicity profile of mitomycin and hyperfractionated RT allows these strategies to be utilized with the newer chemotherapies for this disease.

Preliminary results of phase I trial of oral uracil/tegafur (UFT), leucovorin plus irinotecan and radiation therapy for patients with locally recurrent rectal cancer

BACKGROUND

Surgical attempts for locally recurrent rectal cancer often fail due to local re-recurrence and distant metastasis. Preoperative chemoradiation may enhance better local control and survival. The aim of this study was to assess the safety of oral uracil and tegafur (UFT) plus leucovorin (LV), and irinotecan combined with radiation and determine the maximum-tolerated dose (MTD) and dose limiting toxicity (DLT) of the triple drug regimen.

PATIENTS AND METHODS

Patients with locally recurrent rectal cancer received escalating doses of irinotecan on days 1, 8, 15, and 22 (starting at 30 mg/m2, with 10 mg increments between consecutive cohorts) and fixed doses of UFT (300 mg/m2) plus LV (75 mg/day) on days 3 to 7, 10 to 14, 17 to 21, and 24 to 28. Radiation was given 5 days per week totaling 40 to 50 Gy (2Gy/day).

RESULTS

Six patients were treated at the starting dose, and 2 received the full scheduled chemoradiotherapy. The other 4 patients had grade 3 diarrhea and diarrhea was the DLT. One patient had partial response and he had subsequently radical surgical resection. Median progression free survival for local recurrence was 320 days.

CONCLUSION

Irinotecan plus UFT/LV with concomitant radiotherapy in patients with locally recurrent rectal cancer was not feasible due to diarrhea in this setting. Modification of the treatment is needed.

Preoperative chemoradiotherapy with concomitant small field boost irradiation for locally advanced rectal cancer: a multi-institutional phase II study (KROG 04-01)

PURPOSE

This study was designed to determine the effect of concomitant small field boost irradiation given during preoperative chemoradiotherapy for patients with locally advanced rectal cancer.

METHODS

The study prospectively enrolled 38 patients scheduled for preoperative chemoradiotherapy. Pelvic radiotherapy of 43.2 Gy/24 fractions was delivered and boost radiotherapy of 7.2 Gy/12 fractions was concomitantly administered during the latter half of the pelvic radiotherapy treatment period. Two cycles of a bolus 5-fluorouracil and leucovorin injection in the first and fifth weeks of radiotherapy were administered. The median time to surgery after completion of chemoradiotherapy was six weeks. Tumor responses to chemoradiotherapy were assessed by using magnetic resonance volumetry and post-chemoradiotherapy pathology tests to determine tumor downstaging and tumor regression rate.

RESULTS

Thirty-six of 38 patients (94.7 percent) underwent the scheduled surgery. The mean tumor volume reduction rate was 70.3 percent, and the clinical response rate was 66.7 percent. The downstaging rates were 41.7 percent for T classification, 85.2 percent for N classification, and 72.2 percent for stage. Tumor regression grades after preoperative chemoradiotherapy were Grade 1 in 5 patients (13.9 percent), Grade 2 in 24 patients (66.7 percent), Grade 3 in 3 patients (8.3 percent), and Grade 4 in 4 patients (11.1 percent). Ten patients (26.3 percent) experienced > or = Grade 3 acute toxicity.

CONCLUSIONS

Our data suggest that concomitant boost irradiation does not improve clinical outcomes compared with other published preoperative chemoradiotherapy regimens. In addition, the clinicians choosing to use concomitant small field boost irradiation should be cautious to minimize the risk of unplanned sphincter ablation.

Phase II study of capecitabine (Xeloda®) and concomitant boost radiotherapy in patients with locally advanced rectal cancer

PURPOSE

The aim of this study was to determine the efficacy of capecitabine (Xeloda), an oral fluoropyrimidine, as a radiosensitizer in the neoadjuvant treatment of locally advanced rectal cancer (LARC).

METHODS AND MATERIALS

We conducted a phase II study of capecitabine (825 mg/m2 orally, twice daily continuous) with radiotherapy (52.5 Gy/30 fractions to the primary tumor and perirectal nodes) in 54 patients with LARC (node-negative > or = T3 or any node-positive tumor) staged by endoscopic ultrasound (EUS). The primary endpoint was pathologic response rate; secondary endpoints included toxicity profiles and survival parameters.

RESULTS

Of the 54 patients (median age, 56.7 years; range, 21.3-78.7 years; male:female ratio, 1.7; Eastern Cooperative Oncology Group performance status 0-1: 100%), 51 patients (94%) had T3N0 or T3N1 disease by EUS. Surgery was not performed in 3 patients; 2 of these patients had metastatic disease, and the third patient refused after a complete clinical response. Of the 51 patients evaluable for pathologic response, 9 patients (18%) achieved complete response, and 12 patients (24%) had microscopic residual disease (< 10% viable cells). In addition, 26 patients of all 54 patients (51%) achieved T-downstaging, and 15 patients of 29 patients (52%) achieved N-downstaging. Grade 3/4 toxicities were radiation dermatitis (9%) and diarrhea (2%). Sphincter preservation rate for tumor < or = 5 cm from the anal verge was 67% (18/27).

CONCLUSION

This regimen of radiotherapy plus capecitabine is well tolerated and is more convenient than protracted venous infusion of 5-FU. The pathologic response rate is comparable to our previous experience using protracted venous infusion 5-FU for LARC.

Phase I trial of cetuximab in combination with capecitabine, weekly irinotecan, and radiotherapy as neoadjuvant therapy for rectal cancer

PURPOSE

To establish the feasibility and efficacy of chemotherapy with capecitabine, weekly irinotecan, cetuximab, and pelvic radiotherapy for patients with locally advanced rectal cancer.

METHODS AND MATERIALS

Twenty patients with rectal cancer (clinical Stage uT3-T4 or N+) received a standard dosing regimen of cetuximab (400 mg/m(2) on Day 1 and 250 mg/m(2) on Days 8, 15, 22, and 29) and escalating doses of irinotecan and capecitabine according to phase I methods: dose level I, irinotecan 40 mg/m(2) on Days 1, 8, 15, 22, and 29 and capecitabine 800 mg/m(2) on Days 1-38; dose level II, irinotecan 40 mg/m(2) and capecitabine 1000 mg/m(2); and dose level III, irinotecan 50 mg/m(2) and capecitabine 1000 mg/m(2). Radiotherapy was given to a dose of 50.4 Gy (45 Gy plus 5.4 Gy). Resection was scheduled 4-5 weeks after termination of chemoradiotherapy.

RESULTS

On dose level I, no dose-limiting toxicities occurred; however, Grade 3 diarrhea affected 1 of 6 patients on dose level II. Of 5 patients treated at dose level III, 2 exhibited dose-limiting toxicity (diarrhea in 2 and nausea/vomiting in 1). Therefore, dose level II was determined as the recommended dose for future studies. A total of 10 patients were treated on dose level II and received a mean relative dose intensity of 100% of cetuximab, 94% of irinotecan, and 95% of capecitabine. All patients underwent surgery. Five patients had a pathologically complete remission and six had microfoci of residual tumor only.

CONCLUSION

Preoperative chemoradiotherapy with cetuximab, capecitabine, and weekly irinotecan is feasible and well tolerated. The preliminary efficacy is very promising. Larger phase II trials are ongoing.