Adjuvant versus neoadjuvant radiochemotherapy for locally advanced rectal cancer. A progress report of a phase-III randomized trial (protocol CAO/ARO/AIO-94)

Effect of adjuvant chemotherapy on the oncological outcome of rectal cancer patients with pathological complete response

BACKGROUND

Locally advanced rectal cancer is typically treated using a combination of neoadjuvant chemoradiotherapy and total mesorectal resection. While achieving pathological complete response following neoadjuvant chemoradiotherapy has been recognized as a positive prognostic factor in oncology, the necessity of adjuvant chemotherapy for locally advanced rectal cancer patients with pathological complete response after surgery remains uncertain. The objective of this meta-analysis was to examine the impact of adjuvant chemotherapy on the oncological outcomes of rectal cancer patients who attain pathological complete response after neoadjuvant chemoradiotherapy.

METHODS

This meta-analysis followed the guidelines outlined in the preferred reporting items for systematic review and meta-analysis (PRISMA). The Web of Science, PubMed, and Cochrane Library databases were systematically searched to identify relevant literature.

RESULTS

A total of 34 retrospective studies, including 9 studies from the NCBD database, involving 31,558 patients with pathological complete response rectal cancer, were included in the meta-analysis. The included studies were published between 2008 and 2023. The pooled analysis demonstrated that adjuvant chemotherapy significantly improved overall survival (HR = 0.803, 95% CI 0.678-0.952, P = 0.011), and no heterogeneity was observed (I2 = 0%). Locally advanced rectal cancer patients with pathological complete response who underwent adjuvant chemotherapy exhibited a higher 5-year overall survival rate compared to those who did not receive adjuvant chemotherapy (OR = 1.605, 95% CI 1.183-2.177, P = 0.002). However, the analysis also revealed that postoperative ACT did not lead to improvements in disease-free survival and recurrence-free survival within the same patient population. Subgroup analysis indicated that pathological complete response patients with clinical stage T3/T4, lymph node positivity, and younger than 70 years of age may benefit from adjuvant chemotherapy in terms of overall survival.

CONCLUSIONS

The findings of this meta-analysis suggest that adjuvant chemotherapy has a beneficial effect on improving overall survival among rectal cancer patients with pathological complete response. However, no such association was observed in terms of disease-free survival and recurrence-free survival.

Using Multi-Scale Convolutional Neural Network Based on Multi-Instance Learning to Predict the Efficacy of Neoadjuvant Chemoradiotherapy for Rectal Cancer

Background: At present, radical total mesorectal excision after neoadjuvant chemoradiotherapy is crucial for locally advanced rectal cancer. Therefore, the use of histopathological images analysis technology to predict the efficacy of neoadjuvant chemoradiotherapy for rectal cancer is of great significance for the subsequent treatment of patients. Methods: In this study, we propose a new pathological images analysis method based on multi-instance learning to predict the efficacy of neoadjuvant chemoradiotherapy for rectal cancer. Specifically, we proposed a gated attention normalization mechanism based on the multilayer perceptron, which accelerates the convergence of stochastic gradient descent optimization and can speed up the training process. We also proposed a bilinear attention multi-scale feature fusion mechanism, which organically fuses the global features of the larger receptive fields and the detailed features of the smaller receptive fields and alleviates the problem of pathological images context information loss caused by block sampling. At the same time, we also designed a weighted loss function to alleviate the problem of imbalance between cancerous instances and normal instances. Results: We evaluated our method on a locally advanced rectal cancer dataset containing 150 whole slide images. In addition, to verify our method’s generalization performance, we also tested on two publicly available datasets, Camelyon16 and MSKCC. The results show that the AUC values of our method on the Camelyon16 and MSKCC datasets reach 0.9337 and 0.9091, respectively. Conclusion: Our method has outstanding performance and advantages in predicting the efficacy of neoadjuvant chemoradiotherapy for rectal cancer. Clinical and Translational Impact Statement—This study aims to predict the efficacy of neoadjuvant chemoradiotherapy for rectal cancer to assist clinicians quickly diagnose and formulate personalized treatment plans for patients.

Adjuvant chemotherapy for rectal cancer with complete pathological response (pCR) may not be necessary: a pooled analysis of 5491 patients

Background

It is recommended postoperative adjuvant chemotherapy for all rectal cancers undergoing neo-chemoradiotherapy regardless of the final yield pathology. However, the role of adjuvant chemotherapy in pathological complete response (pCR) remains controversial. We aimed to identify the necessarily of adjuvant chemotherapy in pCR.

Methods

Consecutive patients with pCR in Fudan University Shanghai Cancer Center (FUSCC) were enrolled. Meanwhile, a pooled analysis of individual patient with pCR was performed from PubMed and Embase databases for validation.

Results

A total of 171 patients form FUSCC were identified to achieve pCR with up to almost 10 years follow-up. Among them, those receiving adjuvant chemotherapy had no survival benefits compared to those without adjuvant chemotherapy (log-rank test = 0.17, P = 0.676). The 5y-DFS rates for patients in chemo group and no-chemo group was 87.5 and 88.8%, respectively, showing no significant difference (p = 0.854). No matter chemotherapy regimens, T stage, EMVI and CRM status varied, the results remained consistent. Meantime, the COX model did not demonstrate adjuvant chemotherapy as the independent risk factor for OS and DFS. Additionally, among 18 systemic recurrences in all, the rate of relapse surged rapidly on the 12 months and rose up to peak in the 36th months. In order to validate these results, nine controlled trials involving 5491 patients with pCR were included in this pooled-analysis. For both 5-year overall survival and disease-free survival, the pooling data did not produce a statistically significant effect in cases of adjuvant chemotherapy performed (RR = 0.79 and RR = 0.95, respectively, all p > 0.05).

Conclusion

This study suggested that rectal cancer patients with pCR did not benefit from adjuvant chemotherapy and we recommended that achievement of pCR require more prolonged close follow care in case of distant metastasis.

Effects of Preoperative Radiochemotherapy with Capecitabine for Resectable Locally Advanced Rectal Cancer in Elderly Patients

Aims and background

Rectal cancer is a common disease of elderly people. However, patients over 70 years of age are often not included in clinical trials. There is a lack of data concerning the use of radiochemotherapy with capecitabine in elderly patients. The aim of this study was to retrospectively evaluate the impact of preoperative radiochemotherapy with capecitabine on downstaging and sphincter preservation and to assess treatment compliance and toxicity in elderly patients.

Methods

Twenty-six patients with resectable locally advanced rectal cancer (stage II-III/TNM) aged >70 years received preoperative radiotherapy and concurrent oral capecitabine 825 mg/m2 twice daily during the whole period of radiotherapy. Two patients who refused surgery after chemoradiation therapy were excluded from the analysis.

Results

Eighty-one percent of patients underwent anterior resection and 18.1% underwent abdominoperineal resection. Overall tumor downstaging, considering both T and N categories, was observed in 18/24 patients (75%). Treatment compliance was good and toxicity rates were similar to those of younger people.

Conclusions

Age is not a contraindication to any therapy and elderly patients who can tolerate radiochemotherapy should be treated like younger patients. Preoperative radiochemotherapy with capecitabine for patients aged >70 years has a good impact on tumor downstaging, increases the feasibility of sphincter-preserving surgery, and is also safe and well tolerated.

Oncologic and Functional Hazards of Obesity Among Patients With Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiation Therapy

OBJECTIVE

Obesity is a major health concern and risk factor for colorectal cancer that may also impact cancer treatment and outcomes. Rectal cancer response to chemoradiotherapy (CXRT) is associated with long-term survival and sphincter preservation. The purpose of this study was to evaluate the impact of obesity on treatment outcomes after neoadjuvant CXRT for rectal cancer.

METHODS

A retrospective cohort study of patients diagnosed (1993 to 2010) with cT3-4 or cN+ (by endorectal ultrasound, computed tomography, or magnetic resonance imaging) rectal carcinoma and treated with CXRT and total mesorectal excision was performed. Patients were classified as obese (body mass index ≥30 kg/m) or nonobese (body mass index <30 kg/m), and by response to CXRT: complete (pCR) or incomplete (pIR). Associations between obesity, tumor response, and sphincter preservation were evaluated using multivariate logistic regression analysis and survival outcomes by Cox regression.

RESULTS

A total of 753 patients met criteria and 28.7% (n=216) patients were obese. Obese and nonobese groups did not differ in age, sex, tumor location, grade, or number of examined lymph nodes. However, obesity was associated with a lower rate of pCR (ORmulti=0.60; 95% confidence interval, 0.38-0.94; P=0.04) and among mid to low rectal cancer patients, a lower rate of sphincter preservation (ORmulti=0.67; 95% confidence interval, 0.45-0.99). Among both obese and nonobese patients, CR was associated with more favorable recurrence-free survival than pIR.

CONCLUSIONS

Considering the increasing obesity prevalence and its association with CXRT response, oncologic outcomes, and sphincter preservation, further study is needed regarding the impact of obesity on neoadjuvant treatment response. Moreover, obesity should be targeted as a modifiable risk factor for adverse outcomes following multimodality treatment for rectal cancer.

Identification of Predictive Markers for Response to Neoadjuvant Chemoradiation in Rectal Carcinomas by Proteomic Isotope Coded Protein Label (ICPL) Analysis

Neoadjuvant chemoradiation (nCRT) is an established procedure in stage union internationale contre le cancer (UICC) II/III rectal carcinomas. Around 53% of the tumours present with good tumor regression after nCRT, and 8%–15% are complete responders. Reliable selection markers would allow the identification of poor or non-responders prior to therapy. Tumor biopsies were harvested from 20 patients with rectal carcinomas, and stored in liquid nitrogen prior to therapy after obtaining patients’ informed consent (Erlangen-No.3784). Patients received standardized nCRT with 5-Fluoruracil (nCRT I) or 5-Fluoruracil ± Oxaliplatin (nCRT II) according to the CAO/ARO/AIO-04 protocol. After surgery, regression grading (Dworak) of the tumors was performed during histopathological examination of the specimens. Tumors were classified as poor (Dworak 1 + 2) or good (Dworak 3 + 4) responders. Laser capture microdissection (LCM) for tumor enrichment was performed on preoperative biopsies. Differences in expressed proteins between poor and good responders to nCRT I and II were identified by proteomic analysis (Isotope Coded Protein Label, ICPL™) and selected markers were validated by immunohistochemistry. Tumors of 10 patients were classified as histopathologically poor (Dworak 1 or 2) and the other 10 tumor samples as histopathologically good (Dworak 3 or 4) responders to nCRT after surgery. Sufficient material in good quality was harvested for ICPL analysis by LCM from all biopsies. We identified 140 differentially regulated proteins regarding the selection criteria and the response to nCRT. Fourteen of these proteins were synchronously up-regulated at least 1.5-fold after nCRT I or nCRT II (e.g., FLNB, TKT, PKM2, SERINB1, IGHG2). Thirty-five proteins showed a complete reciprocal regulation (up or down) after nCRT I or nCRT II and the rest was regulated either according to nCRT I or II. The protein expression of regulated proteins such as PLEC1, TKT, HADHA and TAGLN was validated successfully by immunohistochemistry. ICPL is a valid method to identify differentially expressed proteins in rectal carcinoma tissue between poor vs. good responders to nCRT. The identified protein markers may act as selection criteria for nCRT in the future, but our preliminary findings must be reproduced and validated in a prospective cohort.

Factors associated with use of preoperative chemoradiation therapy for rectal cancer in the Cancer Care Outcomes Research and Surveillance Consortium

PURPOSE

Preoperative (preop) chemoradiation therapy (CRT) improves local control and reduces toxicity more than postoperative (postop) CRT for the treatment of stages II/III rectal cancer, but studies suggest that many patients still receive postop CRT. We examined patient beliefs and clinical and provider characteristics associated with receipt of recommended therapy.

METHODS

We identified stages II/III rectal cancer patients who had primary site resection and CRT among subjects in the Cancer Care Outcomes Research and Surveillance Consortium, a population-based and health system-based prospective cohort of newly diagnosed colorectal cancer patients from 2003 to 2005. Patient surveys and abstracted medical records were used to construct variables and determine sequence of CRT and surgery. Logistic regression was used to model the association between predictors and receipt of preop CRT.

RESULTS

Of the 201 patients, 66% received preop and 34% received postop CRT. Those visiting a medical oncologist and/or radiation oncologist before a surgeon had a 96% (95% confidence interval, 92%-100%) predicted probability of receiving preop CRT, compared with 48% (95% confidence interval, 41%-55%) for those visiting a surgeon first. Among those visiting a surgeon first, documentation of recommended staging procedures was associated with receiving preop CRT.

CONCLUSIONS

Sequence of provider visits and documentation of recommended staging procedures were important predictors of receiving preop CRT. Initial multidisciplinary evaluation led to better adherence to CRT guidelines. Further evaluation of provider characteristics, referral patterns, and related health system processes should be undertaken to inform targeted interventions to reduce variation from recommended care.

[Preoperative radiotherapy for rectal cancer: target volumes]

Preoperative radiochemotherapy followed by total mesorectal excision is the standard of care for T3-T4-N0 or TxN1 rectal cancer. Defining target volumes relies on the patterns of nodal and locoregional failures. The lower limit of the clinical target volume depends also on the type of surgery. Conformational radiotherapy with or without intensity-modulated radiotherapy implies an accurate definition of volumes and inherent margins in the context of mobile organs such as the upper rectum. Tumoral staging recently improved with newer imaging techniques such as MRI with or without USPIO and FDG-PET-CT. The role of PET-CT remains unclear despite encouraging results and MRI is a helpful tool for a reliable delineation of the gross tumour volume. Co-registration of such modalities with the planning CT may particularly guide radiation oncologists through the gross tumour volume delineation. Acute digestive toxicity can be reduced with intensity modulation radiation therapy. Different guidelines and CT-based atlas regarding the target volumes in rectal cancer give the radiation oncologist a lot of ground for reproducible contours.

Risk adjusted benchmarking of clinical anastomotic leakage rate after total mesorectal excision in the context of an improvement project

AIM

Anastomotic leakage (AL) after total mesorectal excision (TME) is a major adverse event. This study evaluates variability in AL between centres participating on a voluntary basis in PROCARE, a Belgian improvement project, and how further improvement of the AL rate might be achieved.

METHOD

Between January 2006 and March 2011, detailed data on 1815 patients (mean age 65.5 years, 63% male) who underwent elective TME with colo-anal reconstruction for rectal cancer were registered by 48 centres. Variability in early clinical AL rate was analysed before and after adjustment for gender, age > 60 years, American Society of Anesthesiologists score of 3 or more and body mass index > 25 kg/m(2).

RESULTS

The overall AL rate was 6.7% (95% CI 5.6%-7.9%). Early AL required reoperation in 86.8% of patients. It increased length of hospital stay from 14.7 days to 32.4 days and in-hospital mortality from 1.1% to 4.8%. Statistically significant variability in AL rate between centres was not observed, either before or after risk adjustment. Nonetheless, further improvement may be achievable in some centres by targeting the adjusted performance of better performing centres. These centres used neoadjuvant treatment, rectal irrigation, mobilization of the splenic flexure, resection of the sigmoid colon, side-to-end colo-anastomosis with or without pouch and defunctioning stoma at primary surgery in a significantly higher proportion of patients than less well performing centres.

CONCLUSION

The overall AL rate was low but needs to be interpreted with caution because of incomplete registration. Further improvement might be achieved by adopting the approach of better performing centres.

Long-term follow-up of preoperative pelvic radiation therapy and concomitant boost irradiation in locally advanced rectal cancer patients: a multi-institutional phase II study (KROG 04-01)

PURPOSE

To perform a prospective phase II study to investigate the efficacy and safety of preoperative pelvic radiation therapy and concomitant small-field boost irradiation with 5-fluorouracil and leucovorin for 5 weeks in locally advanced rectal cancer patients.

METHODS AND MATERIALS

Sixty-nine patients with locally advanced, nonmetastatic, mid-to-lower rectal cancer were prospectively enrolled. They had received preoperative chemoradiation therapy and total mesorectal excision. Pelvic radiation therapy of 43.2 Gy in 24 fractions plus concomitant boost radiation therapy of 7.2 Gy in 12 fractions was delivered to the pelvis and tumor bed for 5 weeks. Two cycles of 5-fluorouracil and leucovorin were administered for 3 days in the first and fifth week of radiation therapy. The pathologic response, survival outcome, and treatment toxicity were evaluated for the study endpoints.

RESULTS

Of 69 patients, 8 (11.6%) had a pathologically complete response. Downstaging rates were 40.5% for T classification and 68.1% for N classification. At the median follow-up of 69 months, 36 patients have been followed up for more than 5 years. The 5-year disease-free survival (DFS) and overall survival rates were 66.0% and 75.3%, respectively. Higher pathologic T (P=.045) and N (P=.032) classification were significant adverse prognostic factors for DFS, and high-grade histology was an adverse prognostic factor for both DFS (P=.025) and overall survival (P=.031) on the multivariate analysis. Fifteen patients (21.7%) experienced grade 3 or 4 acute toxicity, and 7 patients (10.1%) had long-term toxicity.

CONCLUSION

Preoperative pelvic radiation therapy with concomitant boost irradiation with 5-fluorouracil and leucovorin for 5 weeks showed acceptable acute and long-term toxicities. However, the benefit of concomitant small-field boost irradiation for 5 weeks in rectal cancer patients was not demonstrated beyond conventional irradiation for 6 weeks in terms of tumor response and survival.

Dose--volume effects on patient-reported acute gastrointestinal symptoms during chemoradiation therapy for rectal cancer

PURPOSE

Research on patient-reported outcomes (PROs) in rectal cancer is limited. We examined whether dose-volume parameters of the small bowel and large bowel were associated with patient-reported gastrointestinal (GI) symptoms during 5-fluorouracil (5-FU)-based chemoradiation treatment for rectal cancer.

METHODS AND MATERIALS

66 patients treated at the Brigham & Women's Hospital or Massachusetts General Hospital between 2006 and 2008 were included. Weekly during treatment, patients completed a questionnaire assessing severity of diarrhea, urgency, pain, cramping, mucus, and tenesmus. The association between dosimetric parameters and changes in overall GI symptoms from baseline through treatment was examined by using Spearman's correlation. Potential associations between these parameters and individual GI symptoms were also explored.

RESULTS

The amount of small bowel receiving at least 15 Gy (V15) was significantly associated with acute symptoms (p = 0.01), and other dosimetric parameters ranging from V5 to V45 also trended toward association. For the large bowel, correlations between dosimetric parameters and overall GI symptoms at the higher dose levels from V25 to V45 did not reach statistical significance (p = 0.1), and a significant association was seen with rectal pain from V15 to V45 (p < 0.01). Other individual symptoms did not correlate with small bowel or large bowel dosimetric parameters.

CONCLUSIONS

The results of this study using PROs are consistent with prior studies with physician-assessed acute toxicity, and they identify small bowel V15 as an important predictor of acute GI symptoms during 5-FU-based chemoradiation treatment. A better understanding of the relationship between radiation dosimetric parameters and PROs may allow physicians to improve radiation planning to optimize patient outcomes.

Novel Carcinoembryonic-Antigen-(CEA)-Specific Pretargeting System to Assess Tumor Cell Viability after Irradiation of Colorectal Cancer Cells

PURPOSE

To date, no valid imaging modality exists for early response prediction to neoadjuvant radiochemotherapy in carcinoembryonic-antigen-(CEA)-expressing rectal cancers (UICC stages II and III). It is hypothesized that the uptake of an anti-CEA antibody is directly related to the number of viable tumor cells and may be quantified by immuno-positron emission tomography (immuno-PET). Therefore, we evaluated a novel pretargeting system using TF2, a humanized bispecific trivalent monoclonal antibody (mAb), directed against CEA and the IMP-288-peptide, a hapten for binding radiometals for imaging. Uptake and kinetics of the pretargeting system were investigated in vitro prior to and after irradiation.

METHODS

TF2 was labeled with ¹³¹I and IMP-288 with ¹¹¹InCl₃. The colorectal cancer cell lines HT29, SW480, and T84 with known varying CEA expression were incubated (≤ 72 hours) with ¹³¹I-TF2 or the TF2-¹¹¹In-IMP-288 pretargeting system. Parallel cultures were irradiated with 2-10 Gy high-energy photons. Tracer uptake, proliferation, apoptosis, and CEA-RNA expression of cancer cells were investigated.

RESULTS

The uptake of tracers was dependent on CEA expression and cell count of the cell lines (uptake/10⁶ cells: 0.3% in HT29, 1.5% in SW480, and 14% in T84, p < 0.001). The TF2-¹¹¹In-IMP-288 pretargeting system showed a higher uptake after 4 and 72 hours compared to (131)I-TF2 in parallel cultures. Only in one cell line (SW480) an increased apoptosis after irradiation could be detected. Irradiation increased dose dependently both the specific uptake of ¹³¹I-TF2 and of the TF2-¹¹¹In-IMP-288 system (4-fold in HT29 and T84 after 10 Gy (72 hours), p < 0.001). These results were CEA-mRNA independent.

CONCLUSION

This novel pretargeting system allows the quantitative analysis of CEA-expressing colorectal cancer cells and represents a promising tool for evaluation of tumor cell viability after irradiation.

Temporal and regional variations in the use of preoperative radiation therapy for rectal cancer

OBJECTIVE

Preoperative (preop) chemoradiation therapy improves local control and reduces toxicity for stage II/III rectal cancer better than postoperative (postop) chemoradiation therapy. We examined the temporal and regional variations in the use of preop radiotherapy (RT) across the United States.

METHODS

Patients with stage II/III rectal cancer diagnosed between 1998 and 2005 who had a primary site resection were identified from the SEER database. The rate of preop RT use over time was plotted. Regression models were used to analyze regional variations.

RESULTS

From 1998 to 2005, an increase of 1.7 in the ratio of preop RT/postoperative RT was noted, whereas the ratio of RT/no RT increased only by 0.7. The ratio of preop RT/postop RT increased from 0.5 to 1 in 5 years (1998-2003) but from 1 to 1.5 in 2 years (2003-2005). Multivariate regression analysis showed: patients with stage II disease were more likely than those with stage III disease, younger patients were more likely than older patients, and males were more likely than females to receive preop RT. Whites were more likely to receive preop RT than nonwhites for stage III disease only. Patients treated in the San Francisco region, Hawaii, New Mexico, Seattle, and Los Angeles were more likely to receive preop RT than were patients in the Connecticut, Detroit, Iowa, Utah, Atlanta, and San Jose/Monterey regions.

CONCLUSIONS

The increasing use of preop RT varies across US regions and patient subgroups. Further studies should evaluate potentially modifiable factors contributing to these variations.

Survival benefit with radiation therapy in node-positive breast carcinoma patients

BACKGROUND AND PURPOSE

Postoperative radiation therapy (RT) has been the subject of discussion, especially in patients with one to three positive lymph nodes (< or = 3 pN+) in the axillary dissection. The authors investigated whether postoperative RT provides a survival benefit for pT1-2 pN+ breast cancer patients.

PATIENTS AND METHODS

Patients included were selected from the SEER database (NCI--Surveillance, Epidemiology and End Results, release 2000; n = 24,410) and the UZ Brussel database (1984-2002; n = 1,011) according to the following criteria: women aged 25-95, no previous cancer, unilateral pT1-pT2 breast tumors, total mastectomy (ME) or breast-conserving surgery (BCS), postoperative RT, and an axillary dissection showing at least one pathologic lymph node.

RESULTS

The overall survival (OS) of patients in the SEER and UZ Brussel databases who received postoperative RT was identical. However, patients in the SEER database who did not receive RT had a significantly worse outcome (p < 0.0001). After ME or BCS, all patients (SEER and UZ Brussel) who had > or = 4 pN+ and received RT had comparable outcomes after 15 years. The 15-year OS in the subgroup with ME and < or = 3 pN+ nodes was 57.0% and 46.6% (p = 0.0004) with RT (UZ Brussel) and without RT (SEER), respectively. For BCS and < or = 3 pN+, the same significant difference in OS at 15 years was seen: 63.8% after RT (UZ Brussel) and 60.4% without RT (SEER; p = 0.0029).

CONCLUSION

RT provides a survival benefit in patients with < or = 3 or > or = 4 pN+; the indication for postoperative RT should therefore be adapted in future consensus meetings.

Differences between clinical trial participants and patients in a population-based registry: the German Rectal Cancer Study vs. the Rostock Cancer Registry

PURPOSE

There are few data on whether the samples of randomized phase III studies are representative for cancer patients in general populations.

METHODS

We compared patient and disease characteristics of patients with stage II or III rectal cancer from the German Rectal Cancer Study (657 patients, 1995-2002) or the Rostock Cancer Registry (371 patients, 1997-2003). Differences between the Study and the Registry were analyzed for subgroups who received neoadjuvant chemoradiotherapy before resection or primary resection with or without postoperative chemoradiotherapy.

RESULTS

Study and Registry patients differed in age (median, 61.7 vs. 65.0 years, P < 0.001) and proportion of women (31.3 percent vs. 38.4 percent, P < 0.004). Significant age and gender differences were seen in primary resection but not in neoadjuvant subgroups. In neoadjuvant and in primary resection subgroups, Study participants were more likely than Registry patients to have tumor location in the lower third of the rectum, a higher rate of R0 resection, a greater number of lymph nodes assessed, and fewer T4 tumors. In the primary resection subgroups, Study participants were more likely to have received postoperative chemoradiotherapy. Multivariate analyses showed no effect of population type (Study vs. Registry) on disease-free or overall survival in neoadjuvant subgroups, but increased risk for Registry patients in primary resection subgroups.

CONCLUSIONS

Participants in clinical trials such as the German Rectal Cancer Study are not representative of all cancer patients of a general population. To enable wider extrapolation of results, future studies should include elderly and high-risk patients.

Chemoradiotherapy and adjuvant chemotherapy for rectal cancer

Local recurrence is an important factor in determining the outcome of patients after surgery for rectal cancer, and various attempts have been made to reduce the local recurrence rate. Randomized controlled trials have shown that radiotherapy combined with total mesorectal excision can reduce the local recurrence rate in rectal cancer patients who undergo curative surgery. Chemoradiotherapy is more effective in achieving local control than radiotherapy alone, and preoperative chemoradiotherapy is superior to postoperative chemoradiotherapy in terms of adverse events. Recent advances have led to the identification of potential therapeutic targets such as epidermal growth factor receptor, vascular endothelial growth factor, and endothelial receptors. These new agents have been used in combination with conventional chemoradiotherapy, and higher pathological complete response rates have been reported for such combinations in comparison with conventional regimens. With regard to lateral node dissection, a recent study showed that postoperative chemoradiotherapy was more effective in reducing the local recurrence rate than lateral node dissection. As for adjuvant chemotherapy, one randomized controlled trial showed that patients who received uracil and tegafur as adjuvant therapy had significantly prolonged relapse-free survival times and overall survival times. As well, one metaanalysis has shown the efficacy of oral uracil-tegafur as adjuvant chemotherapy for rectal cancer.

Locally advanced rectal cancer: what is the evidence for induction chemoradiation?

The concept of spatial cooperation in neoadjuvant chemoradiation (CRT) for locally advanced rectal cancer is attractive. Chemotherapy may, as a component of CRT, not only act as a radiosensitizing agent but also potentially eradicate distant micrometastases. Recent trials have demonstrated that the addition of concurrent 5-fluorouracil (5-FU)-based chemotherapy to radiation increases the pathological complete response rate, and reduces local recurrence, but as yet, a survival advantage has not been observed.

AIMS

This review aims to examine the evidence for induction CRT in locally advanced rectal cancer. The endpoints of pathological complete response, a negative circumferential margin, sphincter-sparing surgery, local control, disease-free survival (DFS), and overall survival (OS) are examined, as are acute and late morbidity, surgical complications, and late functional results.

METHODS

The information to produce this review was compiled by searching PubMed and MEDLINE for English language articles published until April 2007. The search term included "induction, neoadjuvant, chemotherapy, radiotherapy, chemoradiation, combined modality" in association with rectal cancer.

CONCLUSIONS

CRT in the European randomized trials of rectal cancer improves tumor downstaging, pathological complete response, and local control over radiotherapy alone, but does not translate into a benefit in terms of longer DFS or OS, or a higher chance of sphincter preservation. Metastatic disease remains a significant problem, which provides a strong rationale for the integration of a second cytotoxic drug, or biologically targeted agents.

The role of radiation therapy for colorectal cancer

Radiation therapy (RT) has been used to treat cancers for more than a century. Recent randomized trials have helped clarify the treatment recommendations in the use of RT for colorectal cancers. This article reviews these trials to illustrate key concepts, places these trials in perspective, and provides direction for future research.

Adjuvant and neoadjuvant chemoradiation or radiotherapy in rectal cancer--a review focusing on open questions

BACKGROUND

The therapy of rectal cancer has been a matter of debate since decades, especially with regard to the benefits of neoadjuvant or adjuvant therapies. Principles of additional therapies have been established nearly two decades ago and are questioned nowadays on the basis of more recently modified operative techniques. Benefits and sequelae of therapies have to be balanced against each other, and it seems somewhat likely that a more differentiated strategy than simply stating that every patient with stage II and III rectal cancer needs chemoradiation or radiotherapy will, in long term, be recommended.

CONCLUSION

It should be kept in mind that results of centers of excellence and of phase-III studies with their positively selected patient populations are not representative for all the patients with rectal cancer and physicians treating them.

The multidisciplinary management of gastrointestinal cancer. Multimodal treatment of rectal cancer

Greater understanding of the natural history of rectal cancer, and the knowledge that a histologically involved circumferential margin due to inadequate lateral dissection confers a high risk of local recurrence have driven technical advances in surgical technique with meticulous surgical dissection along embryological planes. Significant improvements in local control and overall survival have been seen for patients with resectable rectal cancer. However, even high-quality surgery cannot always achieve a curative resection for locally advanced cancers that extend below the levators, having transgressed the mesorectal fascia. Magnetic resonance imaging is now accepted as a practical method of clinical staging, and can accurately predict pre-operatively the likelihood of achieving a clear circumferential margin. Technological advances in radiation planning and new effective cytotoxic drugs also give scope for dealing with unresectable rectal cancer, and the potential for controlling distant micrometastases. Hence, modern multimodal treatment of rectal cancer attempts to integrate surgery, radiotherapy and chemotherapy, and address the two distinct problems of local recurrence and metastatic disease. Multidisciplinary teams achieve the best results. This paper discusses the surgical management of rectal cancer, the pathology, the principles of imaging, and the lessons learnt from randomized trials of radiotherapy and chemoradiation.

EGFR-TK inhibition before radiotherapy reduces tumour volume but does not improve local control: Differential response of cancer stem cells and nontumourigenic cells?

BACKGROUND AND PURPOSE

Waiting times before radiotherapy may reduce tumour control probability due to proliferation of tumour cells. The aim of the experiment was to test whether the growth inhibiting effect of epidermal growth factor receptor (EGFR)-inhibitors after surgery or tumour transplantation results in a lower tumour mass at time of irradiation and can thereby improve local tumour control.

MATERIALS AND METHODS

The EGFR-tyrosine kinase inhibitor BIBX1382BS was applied over 14days starting from microscopically non-in-sano-resection of FaDu tumours or from tumour transplantation, followed by irradiation (5f/5d). Endpoint was local tumour control. In addition, vital tumour areas, pimonidazole hypoxic fraction, BrdU labelling index, and colony forming ability in vitro were tested in control tumours and after BIBX1382BS treatment (starting from transplantation).

RESULTS

The tumour volume at start of irradiation was significantly lower in the BIBX1382BS treated tumours as compared to the control groups by factors of 11 (post-surgery setting) and 2.7 (transplantation setting). However, the reduced volume did not translate into improved local control after irradiation. The TCD(50) values after surgery were 25.4Gy [95% CI 18; 33Gy] in the control group and 30.5Gy [24; 37] in the BIBX1382BS group (p=0.25). Treatment after transplantation resulted in TCD(50) values of 41.1Gy [35; 47] in the control group and 41.1Gy [33; 49] in the BIBX1382BS group (p=1). While the proportion of S-phase cells decreased after BIBX1382BS treatment, no differences were observed between the pimonidazole hypoxic fractions and in vitro colony forming ability.

CONCLUSIONS

EGFR-TK inhibition with BIBX1382BS over 14days between macroscopically complete tumour resection or tumour transplantation and start of radiotherapy significantly reduced tumour volume but did not improve local tumour control. One possible explanation is that the EGFR-TK inhibitor has a higher activity in nontumourigenic cancer cells compared to cancer stem cells. This hypothesis, along with the observation that tumours of similar size were significantly more radiosensitive after surgery than without surgery, warrants further investigation.

Pre-operative radiotherapy and curative surgery for the management of localized rectal carcinoma

BACKGROUND

Preoperative radiotherapy (PRT) has become part of standard practice offered to improve treatment outcomes in patients with rectal cancer.

OBJECTIVES

To determine if PRT improves outcome for patients with localized resectable rectal cancer and how it compared with other adjuvant or neoadjuvant strategies.

SEARCH STRATEGY

A computerized search was performed December 2006 on MEDLINE (from 1966 to December 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL), conference proceedings, using MeSH and textwords where appropriate to identify randomized trials in PRT and rectal cancer. In addition, MetaRegister of Clinical Trials was searched for ongoing trials.

SELECTION CRITERIA

Randomized trials with a PRT arm versus surgery alone, or other neoadjuvant or adjuvant (NA/A) strategies, targeted patients with localized rectal cancer planned for radical surgery were included.

DATA COLLECTION AND ANALYSIS

Trials were selected, data extracted and quality assessed by 2 authors. Quality was assessed using a 14 point checklist. Summary statistics included Hazard ratios and variances (for the outcomes: overall (OA) mortality, cause specific (CS) mortality, any recurrence and local recurrences (LR)) and Odds Ratio (OR) for other outcomes. Potential sources of heterogeneity hypothesized a priori included study quality, biological effective dose (BED), radiotherapy RT technique, and total mesorectal excision (TME) surgery.

MAIN RESULTS

Nineteen trials compared PRT versus surgery alone. Overall (OA) mortality was marginally improved HR 0.93 [95% CI -0.87-1](absolute difference is 2% if the expected survival rate is 60%). Local recurrence (LR) was improved but the magnitude of benefit was heterogeneous across trials. Sensitivity analyses suggested greater benefits in patients treated with BED>30Gy(10) and multiple field RT techniques. There was significantly more pelvic or perineal wound infection, late rectal and sexual dysfunction. Nine trials compared PRT vs. other NA/A. Available evidence did not support an OA mortality or sphincter preserving benefit with the use of combined chemoradiotherapy (CRT) or selective postoperative RT. CRT provides incremental benefit for local control compared with PRT, which was independent of the timing of the CT. There was no significant difference in outcome for different intervals between RT and surgery (2 vs. 8 wk). Dose escalation with endocavitary boost showed significant effect on sphincter preservation.

AUTHORS' CONCLUSIONS

Optimal PRT improves LR, OA mortality, but no increase in sphincter sparing procedure. CRT further increases local control. If the objective is to increase the incidence of sphincter sparing surgery, endocavitary boost showed the most promise. Strategies with the potential to improve outcomes, especially OAS and sphincter sparing while reducing acute and late toxicities (rectal and sexual function) are needed to guide future strategy designs.

Rectal cancer delivery of radiotherapy in adequate time and with adequate dose is influenced by treatment center, treatment schedule, and gender and is prognostic parameter for local control: Results of study CAO/ARO/AIO-94

PURPOSE

The impact of the delivery of radiotherapy (RT) on treatment results in rectal cancer patients is unknown.

METHODS AND MATERIALS

The data from 788 patients with rectal cancer treated within the German CAO/AIO/ARO-94 phase III trial were analyzed concerning the impact of the delivery of RT (adequate RT: minimal radiation RT dose delivered, 4300 cGy for neoadjuvant RT or 4700 cGy for adjuvant RT; completion of RT in <44 days for neoadjuvant RT or <49 days for adjuvant RT) in different centers on the locoregional recurrence rate (LRR) and disease-free survival (DFS) at 5 years. The LRR, DFS, and delivery of RT were analyzed as endpoints in multivariate analysis.

RESULTS

A significant difference was found between the centers and the delivery of RT. The overall delivery of RT was a prognostic factor for the LRR (no RT, 29.6% +/- 7.8%; inadequate RT, 21.2% +/- 5.6%; adequate RT, 6.8% +/- 1.4%; p = 0.0001) and DFS (no RT, 55.1% +/- 9.1%; inadequate RT, 57.4% +/- 6.3%; adequate RT, 69.1% +/- 2.3%; p = 0.02). Postoperatively, delivery of RT was a prognostic factor for LRR on multivariate analysis (together with pathologic stage) but not for DFS (independent parameters, pathologic stage and age). Preoperatively, on multivariate analysis, pathologic stage, but not delivery of RT, was an independent prognostic parameter for LRR and DFS (together with adequate chemotherapy). On multivariate analysis, the treatment center, treatment schedule (neoadjuvant vs. adjuvant RT), and gender were prognostic parameters for adequate RT.

CONCLUSION

Delivery of RT should be regarded as a prognostic factor for LRR in rectal cancer and is influenced by the treatment center, treatment schedule, and patient gender.

Diagnostic and therapy of locally advanced rectal cancer

The aim of the study was to check the results of the protocol with neoadjuvant chemoirradiation for the treatment of locally advanced rectal cancer. The value of preoperative methods for staging of rectal cancer was also studied. In the period 1st of June 2000 - 31st of December 2005, 116 patients were included into the study, all with histologically proven rectal cancer up to 12 cm from anal verge and all with T3/T4 No-2 M0 stage. Median follow up was 48 months. Operability rate was 90,1%, local recurrency 12%, and survival 78%, though only 66% without sign of local or distant recurrency.

Quality of Life assessment through the EORTC questionnaires of locally advanced rectal cancer patients treated with preoperative chemo-radiotherapy

PURPOSE

To assess the quality of life in a group of rectal cancer patients during the treatment period.

MATERIAL AND METHODS

A sample of 83 rectal cancer patients in Dukes' stages B2 or C who started a chemoradiotherapy treatment followed by surgery, have filled in the EORTC core questionnaire QLQC30 and the colorectal module QLQ-CR38, in three moments during the treatment and follow-up periods: at the beginning of the treatment, at the end of the chemoradiotherapy, and after surgery. Clinical and demographic data have also been recorded. Quality of Life scores and changes in them among the three assessments have been calculated.

RESULTS

Quality of life scores of patients who have followed the treatment has been good in most dimensions, and has shown similar to the clinical data. Soft and moderate alterations have appeared in the areas of disease symptoms, treatment toxicity, fatigue, emotional and sexual functioning, and also in functional areas after surgery. Quality of life has been stable or has had small changes in most dimensions. A worsening in toxicity areas has appeared after the neoadyuvant treatment. After surgery there has been a worsening in functional areas, fatigue and appetite loss, and an improvement in diarrhoea.

CONCLUSIONS

Quality of life scores and clinical data indicate that the situation of the patients who have received the treatments has been good. Patients under treatment stood it adequately.

Serum CEA as a predictor for the response to preoperative chemoradiation in rectal cancer

BACKGROUND AND OBJECTIVES

Recent data suggest that good responders to preoperative chemoradiation (CRT) have a favorable prognosis in rectal cancer patients. The aim of this study was to investigate the predictive value of serum carcinoembryonic antigen (CEA) levels for the tumor response to preoperative CRT in rectal cancer patients.

METHODS

The study comprised 141 rectal adenocarcinoma patients who underwent preoperative radiotherapy with 5-fluorouracil (FU) based chemotherapy, followed by radical surgery. The staging workup was consisted of endorectal ultrasound, abdominopelvic computed tomography scan, or magnetic resonance imaging. The outcome parameters were cancer-specific survival and disease-free survival. Pre-CRT clinicopathologic features, including age, gender, location of the tumor, clinical tumor (cT) classification, clinical nodal (cN) classification, and serum CEA levels were investigated as possible predictors for the response to preoperative CRT.

RESULTS

Pathologic complete or near complete responses (good responders, GR) occurred in 26 (19%) patients, while partial or no response (poor responders, PR) occurred in the remaining 115 (81%) patients. GR showed better cancer-specific survival (P = 0.028) and disease-free survival rates (P = 0.011) than PR. Univariate analysis revealed that positive cN and elevated (>5 ng/ml) pre-CRT serum CEA levels are associated with poor tumor response to preoperative CRT. Using logistic regression analysis, elevated pre-CRT serum CEA levels were the only significant predictor for the poor response to CRT (Odd ratio = 2.876, 95% confidence interval = 1.04-7.46, P = 0.041).

CONCLUSIONS

Our data suggest that elevated pre-CRT serum CEA levels are associated with poor tumor response to CRT. Therefore, pre-CRT serum CEA levels provide useful information about tumor response to preoperative CRT in rectal cancer patients.

Short-term preoperative radiotherapy is a safe approach for treatment of locally advanced rectal cancer

BACKGROUND AND AIMS

The Swedish Rectal Cancer Trial (SRCT) demonstrated that a short term regimen of high-dose preoperative radiotherapy (5x5 Gy) not only reduces the risk of local recurrence but also improves overall survival rate. An increase in postoperative mortality and morbidity has also been observed, however. We therefore evaluated early postoperative complications in patients treated with neoadjuvant radiotherapy for locally advanced rectal adenocarcinoma.

PATIENTS/METHODS

Between 2000 and 2004, 85 patients with locally advanced rectal tumors were treated in our institution. Preoperative staging was based on CT scan and, in several cases, on endorectal ultrasonography. They were 55 men and 30 women, with a median age of 68 years. They were retrospectively divided into two groups: Group A, which included 40 patients undergoing preoperative radiotherapy (25 Gy in five fractions) followed by surgery within 1 week, and Group B, which included 45 patients with rectal cancer receiving surgery immediately after diagnosis. Both groups were homogeneous regarding age, gender and preoperative stage of the disease. The two groups were compared for both technical difficulties during operation and rate of postoperative complications.

RESULTS/FINDINGS

No postoperative deaths were recorded in either group. Low anterior resection with total mesorectal excision was performed in all group A patients, whereas eight patients in group B underwent abdominoperineal resection (P<0.05). Diverting stoma was performed in seven patients of group A and it was closed 3-6 months later on every occasion. Postoperative morbidity was not statistically significant between the two groups (40 vs 39%). The rate of postoperative hemorrhage, pelvic or abdominal wound infection, acute urinary infection, and delayed ileus was similar. The percentage of major anastomotic leak was also equivalent (5 vs 6.6%).

INTERPRETATION/CONCLUSION

Short-term preoperative radiotherapy does not increase the rate of postoperative complications and is a safe therapeutic adjunct for the treatment of locally advanced rectal cancer.

Prognostic Significance of Tumor Regression After Preoperative Chemoradiotherapy for Rectal Cancer

Purpose

We assessed the impact of tumor regression grading (TRG) and its value in correlation to established prognostic factors in a cohort of rectal carcinoma patients treated by preoperative chemoradiotherapy (CRT).

Patients and Methods

TRG was evaluated on surgical specimens of 385 patients treated within the preoperative CRT arm of the CAO/ARO/AIO-94 trial: 50.4 Gy was delivered, fluorouracil was given in the first and fifth week, and surgery was performed 6 weeks thereafter. TRG was determined by the amount of viable tumor versus fibrosis, ranging from TRG 4 when no viable tumor cells were detected, to TRG 0 when fibrosis was completely absent. TRG 3 was defined as regression more than 50% with fibrosis outgrowing the tumor mass, TRG 2 was defined as regression less than 50%, and TRG 1 was defined basically as a morphologically unaltered tumor mass. We performed an initially unplanned, hypothesis-generating analysis with respect to the prognostic value of this TRG system.

Results

TRG 4, 3, 2, 1, 0 was found in 10.4%, 52.2%, 13.8%, 15.3%, and 8.3% of the resected specimens, respectively. Five-year disease-free survival (DFS) after CRT and curative resection was 86% for TRG 4, 75% for grouped TRG 2 + 3, and 63% for grouped TRG 0 + 1 (P = .006). On multivariate analysis, the pathologic T category and the nodal status after CRT were the most important independent prognostic factors for DFS.

Conclusion

In this exploratory analysis, complete (TRG 4) and intermediate pathologic response (TRG 2 + 3) suggested improved DFS after preoperative CRT. TRG assessment should be implemented in pathologic evaluation and prospectively validated in further studies.

Radiotherapy and concurrent radiochemotherapy for rectal cancer

Adjuvant radiotherapy with or without chemotherapy has been used widely in an attempt to improve outcome in rectal cancer. For locally advanced disease, postoperative radiochemotherapy significantly improved both local control and overall survival when compared with surgery alone or surgery plus irradiation. This prompted a National Cancer Institute Consensus Conference in the United States in 1990 to recommend postoperative radiochemotherapy for patients with TNM stage II and III rectal cancer as standard treatment. In Europe, several randomized studies tested preoperative radiotherapy in comparison to surgery alone and showed lower local failure rates. A recent meta-analysis concluded that the combination of preoperative radiotherapy and surgery, as compared with surgery alone, significantly improves local control and overall survival. These results are, however, challenged by more recent reports of extraordinarily low local failure rates following improved surgical techniques, including total mesorectal excision. Evidently, the current monolithic approaches to either apply the same schedule of postoperative radiochemotherapy to all patients with stage II/III rectal cancer or to give preoperative intensive short-course radiation according to the Swedish concept for all patients with resectable rectal cancer irrespective of tumor stage and treatment goal (e.g. sphincter preservation), need to be questioned.

Effectiveness of gene expression profiling for response prediction of rectal adenocarcinomas to preoperative chemoradiotherapy

PURPOSE

There is a wide spectrum of tumor responsiveness of rectal adenocarcinomas to preoperative chemoradiotherapy ranging from complete response to complete resistance. This study aimed to investigate whether parallel gene expression profiling of the primary tumor can contribute to stratification of patients into groups of responders or nonresponders.

PATIENTS AND METHODS

Pretherapeutic biopsies from 30 locally advanced rectal carcinomas were analyzed for gene expression signatures using microarrays. All patients were participants of a phase III clinical trial (CAO/ARO/AIO-94, German Rectal Cancer Trial) and were randomized to receive a preoperative combined-modality therapy including fluorouracil and radiation. Class comparison was used to identify a set of genes that were differentially expressed between responders and nonresponders as measured by T level downsizing and histopathologic tumor regression grading.

RESULTS

In an initial set of 23 patients, responders and nonresponders showed significantly different expression levels for 54 genes (P < .001). The ability to predict response to therapy using gene expression profiles was rigorously evaluated using leave-one-out cross-validation. Tumor behavior was correctly predicted in 83% of patients (P = .02). Sensitivity (correct prediction of response) was 78%, and specificity (correct prediction of nonresponse) was 86%, with a positive and negative predictive value of 78% and 86%, respectively.

CONCLUSION

Our results suggest that pretherapeutic gene expression profiling may assist in response prediction of rectal adenocarcinomas to preoperative chemoradiotherapy. The implementation of gene expression profiles for treatment stratification and clinical management of cancer patients requires validation in large, independent studies, which are now warranted.

Determination of operation time in colorectal diseases: Preoperative chemotherapy application

BACKGROUND

Our aim was to determine the time it takes for wound healing to return to normal in cases where patients have undergone preoperative chemotherapy.

MATERIALS AND METHODS

Eighty-four Wistar-albino rats were included in the study. Twelve of them were placed in the control group (Group I), with no further drug administration. Another 12 rats were placed in a sham group (Group II) and were peritoneally injected with 1 cc of isotonic saline solution 5 days a month, for a period of 6 months. The remaining 60 rats were placed in five chemotherapy groups (Groups III-VII) and were administered 20 mg/kg 5-fluorouracil through peritoneal injection, 5 days a month for a period of 6 months. At the end of the sixth cure, 12 rats from the control (Group I), sham (Group II), and chemotherapy groups (Group III) were operated on, and an intestinal transsection was applied to the rectosigmoid junction, followed by one-by-one anastomosis using 5/0 vicryl. Other groups (Groups IV-VI) with chemotherapy treatment were operated on at 1-week intervals and subjected to the same procedure. The subjects were reoperated on on the eleventh day. A full-layer 4 x 4 cm piece was removed from the abdominal wall containing the previous incision line at the middle, for tensile strength pressure measurements. In addition, a 4 cm colon segment was removed for bursting pressure measurements. Plasma albumin and tissue hydroxyproline levels were measured, and fibroblast numbers were counted in the sections prepared from the abdominal wall.

RESULTS

The control and sham groups were found to be similar to each other with respect to all parameters measured (P > 0.05). Significant reductions were observed in all parameters in the early chemotherapy groups compared with the control and sham groups (P <0.05). All parameters measured in Groups V, VI, and VII were found to be similar to those in the control and sham groups (P <0.05).

CONCLUSION

Wound healing is impaired in rats with chemotherapy, but following the second week after the chemotherapy, disrupted parameters return to their normal levels.

Practice parameters for the management of rectal cancer (revised)

The American Society of Colon and Rectal Surgeons is dedicated to assuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Standards Committee is composed of Society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This Committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive, and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Prospective phase II study of preoperative chemoradiation with capecitabine in locally advanced rectal cancer

PURPOSE

Capecitabine is an attractive oral chemotherapeutic agent that has a radiosensitizing effect and tumor-selectivity. This study was performed to evaluate the efficacy and toxicity of preoperative chemoradiation therapy, when used with oral capecitabine, for locally advanced rectal cancer.

MATERIALS AND METHODS

A prospective phase II trial of preoperative chemoradiation for locally advanced adenocarcinomas of the lower two-thirds of the rectum was conducted. A radiation dose of 50 Gy over five weeks and a daily dose of 1650 mg/m(2) capecitabine in two portions was administered during the entire course of radiation therapy. Surgery was performed with standardized total mesorectal excision four to six weeks after completion of the chemoradiation.

RESULTS

Between January 2002 and September 2003, 61 patients were enrolled onto this prospective phase II trial. The pretreatment clinical stages were T3 in 64% (n=39), T4 in 36% (n=22) and N1-2 in 82% (n=50) of these patients. Fifty-six (92%) patients completed the chemoradiation as initially planned and a complete resection performed in 58 (95%). Down-staging was observed in 45 patients (74%) and a pathologic complete response in 6 (10%). Among the 37 patients with tumors located within 5 cm from the anal verge on colonoscopy, 27 (73%) underwent a sphincter-preserving procedure. No grade 3 and 4 proctitis or hematological toxicities were observed.

CONCLUSION

Preoperative chemoradiation therapy with capecitabine achieved encouraging rates of tumor downstaging and sphincter preservation, with a low toxicity profile. This combined modality can be regarded as a safe and effective treatment for locally advanced rectal cancer.

Preoperative versus postoperative chemoradiotherapy for rectal cancer

BACKGROUND

Postoperative chemoradiotherapy is the recommended standard therapy for patients with locally advanced rectal cancer. In recent years, encouraging results with preoperative radiotherapy have been reported. We compared preoperative chemoradiotherapy with postoperative chemoradiotherapy for locally advanced rectal cancer.

METHODS

We randomly assigned patients with clinical stage T3 or T4 or node-positive disease to receive either preoperative or postoperative chemoradiotherapy. The preoperative treatment consisted of 5040 cGy delivered in fractions of 180 cGy per day, five days per week, and fluorouracil, given in a 120-hour continuous intravenous infusion at a dose of 1000 mg per square meter of body-surface area per day during the first and fifth weeks of radiotherapy. Surgery was performed six weeks after the completion of chemoradiotherapy. One month after surgery, four five-day cycles of fluorouracil (500 mg per square meter per day) were given. Chemoradiotherapy was identical in the postoperative-treatment group, except for the delivery of a boost of 540 cGy. The primary end point was overall survival.

RESULTS

Four hundred twenty-one patients were randomly assigned to receive preoperative chemoradiotherapy and 402 patients to receive postoperative chemoradiotherapy. The overall five-year survival rates were 76 percent and 74 percent, respectively (P=0.80). The five-year cumulative incidence of local relapse was 6 percent for patients assigned to preoperative chemoradiotherapy and 13 percent in the postoperative-treatment group (P=0.006). Grade 3 or 4 acute toxic effects occurred in 27 percent of the patients in the preoperative-treatment group, as compared with 40 percent of the patients in the postoperative-treatment group (P=0.001); the corresponding rates of long-term toxic effects were 14 percent and 24 percent, respectively (P=0.01).

CONCLUSIONS

Preoperative chemoradiotherapy, as compared with postoperative chemoradiotherapy, improved local control and was associated with reduced toxicity but did not improve overall survival.

Rectal cancer

Rectal cancer is an important tumour from an epidemiological point of view and represents the benchmark for an optimal use of integrated treatments (surgery, radiotherapy and chemotherapy) in the oncological practice. Performing radio-chemotherapy (best if preoperatively), medical and radiation oncologists are now able to increase survival, to decrease the occurrence of pelvic recurrence and to ameliorate the quality of life of patients. Updated recommendations for the management of these patients are here reported.

Multidetector CT of the colon

Multidetector technology, enabling faster imaging, higher spatial resolution and reduction in radiation dose, increases the role of CT in colonic diagnostic. The higher spatial resolution in the z-direction also changes the way to analyze the images. Instead of reading axial sections, now the colon can be systematically assessed in 3D by scrolling through multiplanar reconstructions or in CT colonography by virtual endoscopy. With ongoing improvements in computer-aided diagnosis CT colonography becomes an alternative to fiberoptic colonocopy for screening (http://www. multiorganscreening.org). In this article we propose a CT examination protocol for the colon, describe the typical imaging findings of different colonic diseases, and summarize the current status of CT colonography.

Impact of T and N stage and treatment on survival and relapse in adjuvant rectal cancer: a pooled analysis

PURPOSE

To determine survival and relapse rates by T and N stage and treatment method in five randomized phase III North American rectal adjuvant studies.

PATIENTS AND METHODS

Data were pooled from 3,791 eligible patients enrolled onto North Central Cancer Treatment Group (NCCTG) 79-47-51, NCCTG 86-47-51, US Gastrointestinal Intergroup 0114, National Surgical Adjuvant Breast and Bowel Project (NSABP) R01, and NSABP R02. Surgery alone (S) was the treatment arm in 179 patients. The remaining patients received adjuvant treatment as follows: irradiation (RT) alone (n = 281), RT + fluorouracil (FU) +/- semustine bolus chemotherapy (CT; n = 779), RT + protracted venous infusion CT (n = 325), RT + FU +/- leucovorin or levamisole bolus CT (n = 1,695), or CT alone (n = 532). Five-year follow-up was available in 94% of surviving patients, and 8-year follow-up, in 62%.

RESULTS

Overall (OS) and disease-free survival were dependent on TN stage, NT stage, and treatment method. Even among N2 patients, T substage influenced 5-year OS (T1-2, 67%; T3, 44%; T4, 37%; P <.001). Three risk groups of patients were defined: (1) intermediate (T1-2/N1, T3/N0), (2) moderately high (T1-2/N2, T3/N1, T4/N0), and (3) high (T3/N2, T4/N1, T4/N2). For intermediate-risk patients, those receiving S plus CT had 5-year OS rates of 85% (T1-2/N1) and 84% (T3/N0), which was similar to results with S plus RT plus CT (T1-2/N1, 78% to 83%; T3/N0, 74% to 80%). For moderately high-risk lesions, 5-year OS ranged from 43% to 70% with S plus CT, and 44% to 80% with S plus RT plus CT. For high-risk lesions, 5-year OS ranged from 25% to 45% with S plus CT, and 29% to 57% with S plus RT plus CT.

CONCLUSION

Different treatment strategies may be indicated for intermediate-risk versus moderately high- or high-risk patients based on differential survival rates and rates of relapse. Use of trimodality treatment for all patients with intermediate-risk lesions may be excessive, since S plus CT resulted in 5-year OS of approximately 85%; however, 5-year disease-free survival rates with S plus CT were 78% (T1-2/N1) and 69%(T3/N0), indicating room for improvement.

How Safe is Adjuvant Chemotherapy and Radiotherapy for Rectal Cancer?

Over the last three decades, a series of clinical trials have led to the use of adjuvant pelvic radiotherapy and chemotherapy in high-risk (T3-4 or N1) rectal cancer. There is a need to improve patient selection in order to identify the group most at risk for recurrent disease. The toxicity of adjuvant therapy should be factored into this consideration. The optimal sequencing of adjuvant therapy before or after surgery, the use of short- or long-course radiotherapy, and the utility of concurrent chemotherapy is currently being examined in randomized controlled trials (RCTs). The aim of this report was to review the morbidity and mortality in all RCTs of adjuvant therapy for rectal cancer.

Chemotherapeutic and biologic agents as radiosensitizers in rectal cancer

Over the past 25 years, important advances have been made in the management of patients with resectable rectal cancer. Clinical studies have shown the efficacy of combined chemoradiation therapy in enhancing resectability and sphincter preservation rates, decreasing local recurrence, and improving survival of patients with rectal cancer. Although 5-fluorouracil (5-FU) remains the standard chemotherapeutic agent used concurrently with radiation therapy, newer chemotherapeutic agents including capecitabine, irinotecan, and oxaliplatin have also been studied as radiosensitizers in this setting. Novel targeted biologic agents including celecoxib and bevacizumab are being explored in combination with standard chemotherapy and radiation therapy. In this review, we will discuss the mechanism of action and the key clinical studies of each agent as a radiosensitizer.

Impact of Preoperative Staging and Chemoradiation Versus Postoperative Chemoradiation on Outcome in Patients With Rectal Cancer: A Decision Analysis

BACKGROUND

Although radical resection and postoperative chemoradiation have been the standard therapy for patients with rectal cancer, preoperative staging by local imaging and chemoradiation are widely used. We used a decision analysis to compare the two strategies for rectal cancer management.

METHODS

We developed a decision model to compare survival outcomes after postoperative chemoradiation versus preoperative staging and chemoradiation in patients aged 70 years with resectable rectal cancer. In the postoperative chemoradiation strategy, patients undergo radical resection and receive postoperative chemoradiation. In the preoperative staging and chemoradiation strategy, patients with locally advanced cancer receive preoperative chemoradiation and radical resection, whereas those with amenable localized tumors undergo local excision. The cohorts of patients were entered into a Markov model incorporating age-adjusted and disease-specific mortality. Outcomes were evaluated by modeling 5-year disease-specific survival for preoperative chemoradiation as less than, equal to, or greater than that of postoperative chemoradiation. Base-case probabilities were derived from published data; the Surveillance, Epidemiology, and End Results (SEER) Program database; and U.S. Life Tables. One-way and two-way sensitivity analyses were performed. The outcome measures were life expectancy and quality-adjusted life expectancy.

RESULTS

Life expectancy and quality-adjusted life expectancy were 9.72 and 8.72 years, respectively, in the postoperative chemoradiation strategy. In the preoperative staging and chemoradiation strategy, life expectancy was 9.36, 9.72, and 10.09 years and quality-adjusted life expectancy was 8.71, 9.04, and 9.37 years when 5-year disease-specific survival was less than, equal to, or greater than that of postoperative chemoradiation, respectively. The decision model was sensitive to differences in the long-term toxicity of pre- and postoperative chemoradiation. When the 5-year disease-specific survival for patients after pre- or postoperative chemoradiation was equal, the decision model was sensitive to surgical mortality and to the probability of residual lymph node disease after local excision.

CONCLUSION

If efficacy and toxicity after preoperative chemoradiation are equal to or better than that after postoperative chemoradiation in patients with locally advanced rectal cancer, then preoperative staging to select patients appropriate for preoperative chemoradiation is beneficial.

Thymidylate synthase, thymidine phosphorylase, dihydropyrimidine dehydrogenase expression, and histological tumour regression after 5-FU-based neo-adjuvant chemoradiotherapy in rectal cancer

Pre-operative 5-fluorouracil (5-FU)-based chemoradiotherapy in locally advanced rectal cancer (UICC-II/III) may significantly reduce local tumour mass. Response to pre-operative treatment, however, varies significantly. Thymidylate synthase (TS), thymidine phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD) are thought to be important predictors for the efficiency of 5-FU-based treatment. The aim of this study was to determine the correlation between TS-, TP-, and DPD-gene expression and the response to 5-FU-based long-term pre-operative chemoradiotherapy assessed by histopathological tumour regression. Additionally, the predictive value of intra-tumoural TS-, TP-, and DPD-gene expression in pre-operative rectal tumour biopsies was assessed by correlation with the histopathological regression grade. Formalin-fixed, paraffin wax-embedded pre-operative biopsies (n = 14) and surgical resection specimens (n = 40) from patients with rectal carcinoma (clinical UICC stage II/III) receiving neo-adjuvant 5-FU-based chemoradiotherapy were studied for TS-, TP-, and DPD-gene expression by quantitative TaqMan real-time PCR after laser microdissection. Results were compared with standardized histopathological tumour regression analysis. There was a significant association between low TS-gene expression in pre-operative tumour biopsies and tumour response (p = 0.02). TS- and TP-gene expression was significantly lower in resection specimens of responders than of non-responders (p = 0.02) when microdissection was used. Statistical significance was even higher when TS and TP were combined (p = 0.0001). For the DPD gene, no significance was found at all. In conclusion, this study shows that TS gene expression in a pretreatment biopsy predicts the response of local rectal cancer to neo-adjuvant 5-FU-based chemoradiotherapy in a high percentage. Moreover, intra-tumoural TS- and TP-gene expression in surgical rectal specimens after neo-adjuvant chemoradiotherapy correlates significantly with histopathological tumour regression when microdissection is applied.

Preoperative chemoradiotherapy versus preoperative radiotherapy in rectal cancer patients: assessment of acute toxicity and treatment compliance

The European Organisation for Research and Treatment of Cancer (EORTC) 22921 four-arm randomised trial questioned the value of preoperative chemoradiation (XRT-CT) versus preoperative radiation (XRT) and the value of additional postoperative chemotherapy (CT) versus none in T3-T4 M0 resectable rectal cancer patients. We report on the preoperative toxicity, treatment compliance and early deaths (all deaths up to 30 days after surgery) of the two treatment modalities in patients who were entered into trial before January 2001. In the XRT Group (group A), patients received 45 Gy, 25 fractions over 5 weeks. In the XRT-CT Group (group B), two 5-day courses of CT were added to the first and fifth weeks of XRT. For each CT course: 5-fluorouracil (5-FU) 350 mg/m2/day and Leucovorin (LV) 20 mg/m2/day were given. 398 and 400 patients started treatment in groups A and B, respectively. Grade 2+acute diarrhoea occurred in 17.3 and 34.3% of patients in groups A and B, respectively (P<0.005). The other side-effects remained unchanged or were only marginally increased. The compliance with RT was 98.5 and 95.5% in groups A and B, respectively. In group B, 78.7 and 71.1% of the patients received 95-105% of the planned CT doses at the first and second courses, respectively. 6 patients died preoperatively, 2 from toxicity in group B. 8 patients (1%) died within the 30 days after surgery in both groups. At the doses recommended in the protocol, the addition of 5-FU-LV to preoperative XRT slightly increased the amount of acute toxicity. However, the compliance with the radiation protocol or the feasibility of surgery did not decrease.

[Indications for neoadjuvant therapy in rectal carcinoma]

Pre- and postoperative adjuvant treatments for locally advanced, operable (R0 resection) rectum carcinoma have led to improved results. In principle, according to the interdisciplinary consensus of the German Cancer Society, the recommended treatment for rectum carcinoma (T3/4; N0; M0; any T stage; N+; M0) is still postoperative adjuvant radiochemotherapy. In the meantime, however, based on the good results obtained from various clinical trials preoperative adjuvant treatment is favored internationally. Not only does this treatment scheme show a comparably better compliance of the patients but it also seems to be better tolerated. One treatment option for resectable T3 tumors immediately followed by surgery is the sole hypofractionated preoperative 3-4 field external beam radiotherapy. An additional benefit can be expected from protracted preoperative radiochemotherapy (single dose 2 Gy, total dose >40 Gy, chemotherapy based on 5-FU) followed by operation several weeks later. For T4 tumors with expected R1 or R2 resection, preoperative treatment is urgently recommended. A further aim in compliance with the surgical approach (R0 resection!) and multimodal treatment may be for individual cases the preservation of continence.

Rectal cancer: preoperative versus postoperative irradiation as a component of adjuvant treatment

The search for improved disease control and survival for resectable but high-risk rectal cancers has led to studies that combine all 3 modalities. For surgically resected, high-risk rectal cancers, postoperative chemoradiation has been shown to improve both disease control (local and distant) and survival (disease free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health Colorectal Cancer Consensus Conference. Three randomized studies showed improved overall survival (OS) and local control for patients treated with postoperative irradiation and chemotherapy when compared with surgery alone or surgery plus irradiation control arms. These include 2 US trials, Gastrointestinal Tumor Study Group and Mayo/North Central Cancer Treatment Group (NCCTG) and a Norway trial. Although most preoperative external beam radiation trials show reductions in local relapse with the addition of preoperative EBRT to resection, only the large Swedish trial of approximately 1,100 patients showed a survival improvement when compared with a surgery alone control arm for resectable primary rectal cancers. In a recent pooled analysis of 3 postoperative adjuvant rectal cancer trials (NCCTG 794751, NCCTG 864751, and GI Intergroup 0114) survival and disease relapse were dependent on both TN and NT stage of disease (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more positive nodes), T substage influenced 5-year OS (T1-2, 69%; T3, 48%; and T4, 38%; P <.001). Ongoing randomized trials are being conducted for patients with high-risk, resectable primary rectal cancers. The intent is to help define optimal combinations of postoperative chemoradiation (US GI Intergroup), to test sequencing issues of preoperative versus postoperative chemoradiation (Germany trial), and to determine if concurrent and maintenance 5-FU and leucovorin add to the benefits found with preoperative irradiation (European Organization for Research and Treatment of Cancer). For subsequent trials, it may be preferable to perform separate studies, or a planned statistical analysis, for different risk groups of patients (low, intermediate, moderately high, and high), as defined in the rectal cancer pooled analysis.