Neoadjuvant therapy before surgical treatment

Neoadjuvant treatment in terms of preoperative radiotherapy reduces local recurrence in rectal cancer, but this improvement has little if any impact on overall survival. Currently performed optimal quality-controlled total mesorectal excision (TME) surgery for patients in the trial setting can be associated with very low local recurrence rates of less than 10% whether the patients receive radiotherapy or not. Hence metastatic disease is now the predominant issue. The concept of neoadjuvant chemotherapy (NACT) is a potentially attractive additional or alternative strategy to radiotherapy to deal with metastases. However, randomised phase III trials, evaluating the addition of oxaliplatin at low doses plus preoperative fluoropyrimidine-based chemoradiotherapy (CRT), have in the main failed to show a significant improvement on early pathological response, with the exception of the German CAO/ARO/AIO-04 study. The integration of biologically targeted agents into preoperative CRT has also not fulfilled expectations. The addition of cetuximab appears to achieve relatively low rates of pathological complete responses, and the addition of bevacizumab has raised concerns for excess surgical morbidity. As an alternative to concurrent chemoradiation (which delivers only 5-6 weeks of chemotherapy), potential options include an induction component of 6-12 weeks of NACT prior to radiotherapy or chemoradiation, or the addition of chemotherapy after short-course preoperative radiotherapy (SCPRT) or chemoradiation (defined as consolidation chemotherapy) which utilises the "dead space" of the interval between the end of chemoradiation and surgery, or delivering chemotherapy alone without any radiotherapy.

Using whole disease modeling to inform resource allocation decisions: economic evaluation of a clinical guideline for colorectal cancer using a single model

OBJECTIVE

To assess the feasibility and value of simulating whole disease and treatment pathways within a single model to provide a common economic basis for informing resource allocation decisions.

METHODS

A patient-level simulation model was developed with the intention of being capable of evaluating multiple topics within National Institute for Health and Clinical Excellence's colorectal cancer clinical guideline. The model simulates disease and treatment pathways from preclinical disease through to detection, diagnosis, adjuvant/neoadjuvant treatments, follow-up, curative/palliative treatments for metastases, supportive care, and eventual death. The model parameters were informed by meta-analyses, randomized trials, observational studies, health utility studies, audit data, costing sources, and expert opinion. Unobservable natural history parameters were calibrated against external data using Bayesian Markov chain Monte Carlo methods. Economic analysis was undertaken using conventional cost-utility decision rules within each guideline topic and constrained maximization rules across multiple topics.

RESULTS

Under usual processes for guideline development, piecewise economic modeling would have been used to evaluate between one and three topics. The Whole Disease Model was capable of evaluating 11 of 15 guideline topics, ranging from alternative diagnostic technologies through to treatments for metastatic disease. The constrained maximization analysis identified a configuration of colorectal services that is expected to maximize quality-adjusted life-year gains without exceeding current expenditure levels.

CONCLUSIONS

This study indicates that Whole Disease Model development is feasible and can allow for the economic analysis of most interventions across a disease service within a consistent conceptual and mathematical infrastructure. This disease-level modeling approach may be of particular value in providing an economic basis to support other clinical guidelines.

A phase II study of temozolomide in patients with advanced aerodigestive tract and colorectal cancers and methylation of the O6-methylguanine-DNA methyltransferase promoter

Responses of patients with gliomas to temozolomide are determined by O(6)-methylguanine-DNA methyltransferase (MGMT) and mismatch repair (MMR) pathways. This phase II study (NCT00423150) investigated whether MGMT promoter methylation predicts response in patients with advanced aerodigestive tract and colorectal cancers (CRC). Tumor and serum samples were screened for MGMT promoter methylation. In methylation-positive patients, 150 mg/m(2) temozolomide was administered daily on a seven-day-on, seven-day-off schedule for each 28-day cycle. The primary efficacy endpoint was response rate (RR). MMR status was determined by a microsatellite instability assay. Among 740 patients screened, 86 were positive for MGMT promoter methylation and enrolled. Nineteen percent of the screened population (137/740) had confirmed tissue and/or serum MGMT promoter methylation, including 25% (57 of 229) for CRC, 36% (55 of 154) for esophageal cancer, 11% (12 of 113) for head and neck cancer, and 5% (13 of 242) for non-small cell lung carcinoma. Among patients with valid methylation results in both tissue and serum samples, concordance was 81% (339 of 419). The majority of enrolled patients (69 of 86; 80%) had microsatellite stable cancer. Overall RR was 6% (5 of 86 partial responses); all responders had microsatellite stable cancer. Temozolomide resulted in low RRs in patients enriched for MGMT methylation. MGMT methylation status varied considerably in the patient population. Although serum methylation assay is an option for promoter methylation detection, tissue assay remains the standard for methylation detection. The low RR of this cohort of patients indicates that MGMT methylation as a biomarker is not applicable to heterogeneous tumor types, and tumor-specific factors may override validated biomarkers.

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

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

To PET or not to PET? That is the question. Staging in anal cancer

BACKGROUND

Anal cancer is a rare tumour accounting for ∼2% of all colorectal cancers between 1997 and 2000 in the UK. Staging is still dominated by DRE (digital rectal examination), computed tomography (CT) and magnetic resonance imaging (MRI) imaging. The role of PET as a definitive modality is still emerging and there are relatively few adequate studies in the literature.

METHODS

We looked at patients treated radically for anal cancer at Mount Vernon Cancer Centre (UK) between 2009 and 2010. Eighty-eight patients underwent treatment according to data-based coding records of which 46 had positron emission tomography (PET)/CT scans. Notes were unavailable for three patients. We compared staging following conventional modalities (DRE, MRI and CT) and PET/CT scans for these 43 patients.

RESULTS

In 18 patients, the PET/CT stage differed from MRI. PET/CT altered the stage in 42% of patients but changes in subsequent management were not implemented.

CONCLUSIONS

Our data show that PET/CT does alter staging in a significant number of cases although it did not lead to change in management under the current guidelines. Furthermore, there is agreement that PET/CT shows greater sensitivity for detection of lymph nodes and our study has demonstrated a distinct trend towards upstaging of anal cancer with PET/CT.

Critical appraisal of the 'wait and see' approach in rectal cancer for clinical complete responders after chemoradiation

BACKGROUND

Some 10-20 per cent of patients with locally advanced rectal cancer achieve a pathological complete response (pCR) at surgery following preoperative chemoradiation (CRT). Some demonstrate a sustained clinical complete response (cCR), defined as absence of clinically detectable residual tumour after CRT, and do not undergo resection. The aim of this review was to evaluate non-operative treatment of rectal cancer after CRT, and the outcome of patients observed without radical surgery.

METHODS

A systematic computerized search identified 30 publications (9 series, 650 patients) evaluating a non-operative approach after CRT. Original data were extracted and tabulated, and study quality evaluated. The primary outcome measure was cCR. Secondary outcome measures included locoregional failure rate, disease-free survival and overall survival.

RESULTS

The most recent Habr-Gama series reported a low locoregional failure rate of 4·6 per cent, with 5-year overall and disease-free survival rates of 96 and 72 per cent respectively. These findings were supported by a small prospective Dutch study. However, other retrospective series have described higher recurrence rates. All studies were heterogeneous in staging, inclusion criteria, study design and rigour of follow-up after CRT, which might explain the different outcomes. The definition of cCR was inconsistent, with only partial concordance with pCR. The results suggested that patients who are observed, but subsequently fail to sustain a cCR, may fare worse than those who undergo immediate tumour resection.

CONCLUSION

The rationale of a 'wait and see' policy relies mainly on retrospective observations from a single series. Proof of principle in small low rectal cancers, where clinical assessment is easy, should not be extrapolated uncritically to more advanced cancers where nodal involvement is common. Long-term prospective observational studies with more uniform inclusion criteria are required to evaluate the risk versus benefit.

Reproducibility of 2D and 3D fractal analysis techniques for the assessment of spatial heterogeneity of regional blood flow in rectal cancer

PURPOSE

To characterize the two-dimensional (2D) and three-dimensional (3D) fractal properties of rectal cancer regional blood flow assessed by using volumetric helical perfusion computed tomography (CT) and to determine its reproducibility.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. Ten prospective patients (eight men, two women; mean age, 72.3 years) with rectal adenocarcinoma underwent two repeated volumetric helical perfusion CT studies (four-dimensional adaptive spiral mode, 11.4-cm z-axis coverage) without intervening treatment within 24 hours, with regional blood flow derived by using deconvolution analysis. Two-dimensional and 3D fractal analyses of the rectal tumor were performed, after segmentation from surrounding structures by using thresholding, to derive fractal dimension and fractal abundance. Reproducibility was quantitatively assessed by using Bland-Altman statistics. Two-dimensional and 3D lacunarity plots were also generated, allowing qualitative assessment of reproducibility. Statistical significance was at 5%.

RESULTS

Mean blood flow was 63.50 mL/min/100 mL ± 8.95 (standard deviation). Good agreement was noted between the repeated studies for fractal dimension; mean difference was -0.024 (95% limits of agreement: -0.212, 0.372) for 2D fractal analysis and -0.024 (95% limits of agreement: -0.307, 0.355) for 3D fractal analysis. Mean difference for fractal abundance was -0.355 (95% limits of agreement: -0.869, 1.579) for 2D fractal analysis and -0.043 (95% limits of agreement: -1.154, 1.239) for 3D fractal analysis. The 95% limits of agreement were narrower for 3D than 2D analysis. Lacunarity plots also visually confirmed close agreement between repeat studies.

CONCLUSION

Regional blood flow in rectal cancer exhibits fractal properties. Good reproducibility was achieved between repeated studies with 2D and 3D fractal analysis.

Neoadjuvant chemotherapy in MRI-staged high-risk rectal cancer in addition to or as an alternative to preoperative chemoradiation?

BACKGROUND

For patients with resectable rectal cancer chemoradiation (CRT) or short-course preoperative radiotherapy (SCPRT) reduces locoregional failure, without extending disease-free survival (DFS) or overall survival (OS). Compliance to postoperative adjuvant chemotherapy is poor. Neoadjuvant chemotherapy (NACT) offers an alternative strategy.

METHODS

A systematic computerised database search identified studies exploring NACT alone or NACT preceding/succeeding radiation. The primary outcome measure was pathological complete response (pCR). Secondary outcome measures included acute toxicity, surgical morbidity, circumferential resection margin, locoregional failure, DFS and OS.

RESULTS

Four case reports, 12 phase I/II studies, 4 randomised phase II and one randomised phase III study evaluated chemotherapy before CRT. Four prospective studies reviewed chemotherapy after CRT. Three phase II studies investigated chemotherapy using FOLFOX plus bevacizumab without radiotherapy. In 24 studies of 1271 patients, pCR varied from 7% to 36%, but with no impact on metastatic disease.

CONCLUSIONS

NACT before CRT delivers does not compromise CRT but has not increased pCR rates, R0 resection rate, improved DFS or reduced metastases. NACT following CRT is an interesting strategy, and the utility of NACT alone could be explored compared with SCPRT or CRT in selected patients with rectal cancer where the impact of radiotherapy on DFS and OS is marginal.

Neoadjuvant treatment in rectal cancer: do we always need radiotherapy-or can we risk assess locally advanced rectal cancer better?

There is good quality evidence that preoperative radiotherapy reduces local recurrence but there is little impact on overall survival. This is not completely unexpected as radiotherapy is a localised treatment and local control may not prevent systemic failure. Optimal quality-controlled surgery for patients with operable rectal cancer in the trial setting can be associated with local recurrence rates of less than 10 % whether patients receive radiotherapy or not (Quirke et al. 2009). However, despite the reassuring results of randomised trials, concerns remain that radiotherapy increases surgical morbidity (Horisberger et al. 2008; Stelzmueller et al. 2009; Swellengrebel et al. 2011), which can compromise the delivery of postoperative adjuvant chemotherapy. There are also significant late effects from pelvic radiotherapy (Peeters et al. 2005; Lange et al. 2007) and a risk of second malignancies (Birgisson et al. 2005; van Gijn et al. 2011). If preoperative radiotherapy does not impact on survival, can it be omitted in selected cases? The answer is yes-with the proviso that we are using good quality magnetic resonance imaging and good quality TME surgery within the mesorectal plane and the predicted risk of subsequent metastatic disease justifies its use. In this case, the concept of neoadjuvant chemotherapy (NACT) is a potentially attractive alternative strategy which might have less early and long-term side effects compared to preoperative radiotherapy-particularly where the MRI predicts a high risk of metastatic disease in the context of a modest risk of local recurrence. This chapter discusses a more precise method of risk categorisation for locally advanced rectal cancer, and discusses possible options for neoadjuvant chemotherapy (NACT).

The diagnosis and management of gastric cancer: expert discussion and recommendations from the 12th ESMO/World Congress on Gastrointestinal Cancer, Barcelona, 2010

Well-recognized experts in the field of gastric cancer discussed during the 12th European Society Medical Oncology (ESMO)/World Congress Gastrointestinal Cancer (WCGIC) in Barcelona many important and controversial topics on the diagnosis and management of patients with gastric cancer. This article summarizes the recommendations and expert opinion on gastric cancer. It discusses and reflects on the regional differences in the incidence and care of gastric cancer, the definition of gastro-esophageal junction and its implication for treatment strategies and presents the latest recommendations in the staging and treatment of primary and metastatic gastric cancer. Recognition is given to the need for larger and well-designed clinical trials to answer many open questions.

Comparison of conventional and three-dimensional conformal CT planning techniques for preoperative chemoradiotherapy for locally advanced rectal cancer

OBJECTIVES

We assessed the impact of three-dimensional (3D) conformal planning vs conventional planning of preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) on small bowel and bladder sparing and in optimising coverage of tumour target volume.

METHODS

Conformal and conventional plans were created for 50 consecutive patients. The conformal plan delineated a gross tumour volume (GTV), a clinical target volume (CTV) 1 to cover potential subclinical disease spread, a CTV2 to outline the mesorectum and lymph node areas at risk, and a planning target volume (PTV) to cover set-up error and organ movement. The conventional plan was created using digitally reconstructed radiographs (DRRs). Patients were treated with a dose of 45 Gy in 25 fractions with concurrent chemotherapy over 5 weeks. Dose-volume histograms (DVHs) were created and compared for GTV, PTV, small bowel and bladder. The GTV was covered by the conventional plan in all patients.

RESULTS

Significant differences were shown for median PTV coverage with conformal planning compared with conventional planning: 99.2% vs 94.2% (range 95.9-100% vs 75.5-100%); p<0.05. The median volume of irradiated small bowel was significantly lower for CT plans at all DVH levels. Median bladder doses did not differ significantly.

CONCLUSION

3D conformal CT planning is superior to conventional planning in terms of coverage of the tumour volume. It significantly reduces the volume of small bowel irradiated with no decrease in the rate of R0 resection compared with published data, and at the present time should be considered as the standard of care for rectal cancer planning.

Evaluation of response after chemoradiation for rectal cancer as a predictive factor for the benefit of adjuvant chemotherapy: A pooled analysis of 2,724 individual patients

361

Background: Neoadjuvant chemoradiation (CRT) for rectal cancer increasingly results in pathologic response. It has been suggested that patients with different degrees of response might not have the same benefit of adjuvant chemotherapy. The aim was to determine whether patients with a pathologic complete response (pCR), ypT1-2 or ypT3-4 tumor after CRT for rectal cancer have different benefits of adjuvant chemotherapy for disease-free survival.

Methods: Authors from studies evaluating different degrees of response to CRT were contacted to share individual patient data. The collected individual patient data were pooled into one dataset. To evaluate the effect of adjuvant chemotherapy on disease-free survival multivariate analyses according to the Cox proportional hazards model were performed. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated for 3 subgroups: patients with pCR(ypT0N0), ypT1-2 tumor and ypT3-4 tumor after CRT. To determine benefit of adjuvant chemo for different pathologic N-stages we performed subgroup analyses.

Results: 2,724 patients were included. 811 had pCR (28%), 863 had ypT1-2 (30%) and 1050 had ypT3-4 (37%). Median follow-up was 50 months (range 0-277). 41% underwent adjuvant chemotherapy, which consisted mostly of 5-FU based chemotherapy. The HR with 95%CI for disease-free survival for adjuvant chemotherapy was 0.94 (0.50-1.78) for patients with pCR, 0.61 (0.40-0.92) for patients with ypT1-2 tumors and 0.97 (0.75-1.25) for patients with ypT3-4 tumors. ypT1-2N0 patients benefited most from adjuvant chemo: HR 0.45 (0.27-0.75) vs. 0.79 (0.31-1.95) for patients with ypT1-2N+. For ypT3-4 patients pN-stage did not alter benefit of adjuvant chemo.

Conclusions: Patients with pCR or ypT3-4 residual tumor after CRT do not seem to benefit from adjuvant chemo. This might be due to the already good prognosis of patients with pCR and less responsiveness to 5-FU based chemotherapy in the poor responders (the ypT3-4 tumors). Possibly adjuvant chemotherapy can be omitted or adapted for these patients. Patients with ypT1-2N0 benefit most from adjuvant chemo.

No significant financial relationships to disclose.

"Mind the gap"--the impact of variations in the duration of the treatment gap and overall treatment time in the first UK Anal Cancer Trial (ACT I)

PURPOSE

The United Kingdom Coordinating Committee on Cancer Research anal cancer trial demonstrated the benefit of combined modality treatment (CMT) using radiotherapy (RT), infusional 5-fluorouracil, and mitomycin C over RT alone. The present study retrospectively examines the impact of the recommended 6-week treatment gap and local RT boost on long-term outcome.

METHODS AND MATERIALS

A total of 577 patients were randomly assigned RT alone or CMT. After a 6-week gap responders received a boost using either additional external beam radiotherapy (EBRT) (15 Gy) or iridium-192 implant (25 Gy). The effect of boost, the gap between initial treatment (RT alone or CMT) and boost (Tgap), and overall treatment time (OTT) were examined for their impact on outcome.

RESULTS

Among the 490 good responders, 436 (89%) patients received a boost after initial treatment. For boosted patients, the risk of anal cancer death decreased by 38% (hazard ratio [HR]: 0.62, 99% CI 0.35-1.12; p=0.04), but there was no evidence this was mediated via a reduction in locoregional failure (LRF) (HR: 0.90, 99% CI 0.48-1.68; p=0.66). The difference in Tgap was only 1.4 days longer for EBRT boost, compared with implant (p=0.51). OTT was longer by 6.1 days for EBRT (p=0.006). Tgap and OTT were not associated with LRF. Radionecrosis was reported in 8% of boosted, compared with 0% in unboosted patients (p=0.03).

CONCLUSIONS

These results question the benefit of a radiotherapy boost after a 6-week gap. The higher doses of a boost may contribute more to an increased risk of late morbidity, rather than local control.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

None.

Suppression of the postoperative neutrophil leucocytosis following neoadjuvant chemoradiotherapy for rectal cancer and implications for surgical morbidity

OBJECTIVE

The extent to which neoadjuvant chemoradiotherapy for rectal cancer influences postoperative morbidity is controversial. This study investigated whether this treatment suppresses the normal perioperative inflammatory response and explored the clinical implications.

METHOD

Prospective databases were queried to identify 37 consecutive study patients undergoing definitive surgery following 5-FU/capecitabine-based chemoradiotherapy and 34 consecutive untreated control patients operated upon for rectal or rectosigmoid cancer. Preoperative (< 10 days) and postoperative (< 24 h) neutrophil counts, along with morbidity data, were confirmed retrospectively. Univariate and multivariate analyses assessed the apparent effect of chemoradiotherapy on change in neutrophil count. The latter's association with postoperative morbidity was then examined.

RESULTS

Sufficient data were available for 34 study and 27 control patients. Repeated-measures ANCOVA revealed significant differences between their perioperative neutrophil counts (P = 0.02). Of the other characteristics which differed between the groups, only age and tumour location were prognostically significant regarding perioperative change in neutrophil count. Accounting for relevant covariates, chemoradiotherapy was significantly associated with a suppressed perioperative neutrophil leucocytosis. Local postoperative complications affected 25 of 61 patients, who had lower perioperative neutrophil increases than their counterparts (P = 0.016).

CONCLUSION

Chemoradiotherapy appears to suppress the perioperative inflammatory response, thereby increasing susceptibility to local postoperative complications.

Cetuximab and chemoradiation for rectal cancer--is the water getting muddy?

The epidermal growth factor receptor (EGFR) inhibitor cetuximab has been successfully combined with radical radiotherapy in head and neck cancer. In colorectal cancer, increased response rates are achieved by cetuximab and panitumumab within standard chemotherapy schedules, but not in chemoradiation regimens. This review examines the clinical evidence and potential mechanisms for an interaction when EGFR inhibitors are added to fluoropyrimidine-based chemoradiation in rectal adenocarcinoma.

METHODS

This review was compiled by searching PubMed and Medline for English language articles published until 2009 with established search strategies, supplemented by hand searching of abstracts from the proceedings of relevant international meetings. The primary outcome measure was pathological complete response (pCR).

RESULTS

Only 13 publications and three presentations in abstract of 13 phase I/II trials of preoperative chemoradiation with cetuximab in rectal cancer were identified. A total of 316 patients were identified who received cetuximab in combination with radiotherapy and 5-fluorouracil or capecitabine preoperatively. One hundred and thirty eight of these patients received either additional irinotecan or oxaliplatin. One study with panitumumab with safety but no efficacy results was identified, and two studies with gefinitib. The pCR rate ranged from 0-20%. The overall pooled pCR for cetuximab based chemoradiation was 9.1% (29/316). The rate of G3/G4 gastrointestinal toxicity, in terms of diarrhoea, varied from 5-30%, with an overall pooled rate of 47/313 (15%).

DISCUSSION

Potential reasons for the disappointing results of EGFR inhibition with fluoropyrimidine-based preoperative chemoradiation include a less critical role of repopulation in rectal adenocarcinoma using a non-curative radiation dose; or antagonistic effects on 5FU-based chemoradiation and oxaliplatin, if some cells arrest in G1 or G2-M and fail to pass through S phase.

CONCLUSION

Cetuximab combined with fluoropyrimidine-based chemoradiation is not currently recommended. A better understanding of the mechanisms involved in combinations of chemotherapy and radiotherapy might allow more effective future scheduling of biological and chemical agents in combination with radiation.

Chemoradiation for the treatment of epidermoid anal cancer: 13-year follow-up of the first randomised UKCCCR Anal Cancer Trial (ACT I)

Background:

The first UKCCCR Anal Cancer Trial (1996) demonstrated the benefit of chemoradiation over radiotherapy (RT) alone for treating epidermoid anal cancer, and it became the standard treatment. Patients in this trial have now been followed up for a median of 13 years.

Methods:

A total of 577 patients were randomised to receive RT alone or combined modality therapy using 5-fluorouracil and mitomycin C. All patients were scheduled to receive 45 Gy by external beam irradiation. Patients who responded to treatment were recommended to have boost RT, with either an iridium implant or external beam irradiation. Data on relapse and deaths were obtained until October 2007.

Results:

Twelve years after treatment, for every 100 patients treated with chemoradiation, there are an expected 25.3 fewer patients with locoregional relapse (95% confidence interval (CI): 17.5–32.0 fewer) and 12.5 fewer anal cancer deaths (95% CI: 4.3–19.7 fewer), compared with 100 patients given RT alone. There was a 9.1% increase in non-anal cancer deaths in the first 5 years of chemoradiation (95% CI +3.6 to +14.6), which disappeared by 10 years.

Conclusions:

The clear benefit of chemoradiation outweighs an early excess risk of non-anal cancer deaths, and can still be seen 12 years after treatment. Only 11 patients suffered a locoregional relapse as a first event after 5 years, which may influence the choice of end points in future studies.

Does adjuvant fluoropyrimidine-based chemotherapy provide a benefit for patients with resected rectal cancer who have already received neoadjuvant radiochemotherapy? A systematic review of randomised trials

BACKGROUND

The results of the recently published large European randomised study in rectal cancer (European Organisation for Research and Treatment of Cancer 22921 trial) do not support current guidelines recommending postoperative chemotherapy for patients who have previously undergone preoperative radiochemotherapy or radiotherapy [radio(chemo)therapy]. To evaluate this discrepancy further, a systematic review of relevant randomised trials was undertaken.

MATERIALS AND METHODS

A systematic literature search was carried out in order to identify randomised studies exploring adjuvant chemotherapy against observation in patients with rectal cancer previously treated with preoperative radio(chemo)therapy.

RESULTS

A statistically significant benefit of adjuvant chemotherapy was not found in any of the four relevant randomised trials. Non-protocolised subgroup analysis of one study indicated a beneficial effect of adjuvant chemotherapy for high rectal tumours and for patients downstaged to ypT0-2N0 but no effect for low-lying rectal tumours. However, the body of evidence indicates that patients downstaged after radio(chemo)therapy to ypT0-2N0 disease are not candidates for testing adjuvant chemotherapy in future trials due to the considerable over-treatment anticipated by this manoeuvre.

CONCLUSIONS

To resolve the issue in question, a meta-analysis of relevant studies is required, and new trials should be launched to explore new drug combinations against observation. Currently, delivery of adjuvant chemotherapy in patients undergoing preoperative radio(chemo)therapy is not evidence based.

A randomized trial of chemoradiation using mitomycin or cisplatin, with or without maintenance cisplatin/5FU in squamous cell carcinoma of the anus (ACT II)

LBA4009

Background: Chemoradiotherapy (CRT) with 5-fluorouracil (5-FU) and mitomycin-C (MMC) is standard treatment for anal cancer. This trial addresses two questions: whether (i) replacing MMC with cisplatin (CDDP) improves the complete response (CR) rate, and (ii) two cycles of maintenance chemotherapy after CRT reduces recurrence. Methods: Between 2001 and 2008, 940 patients (pts) were recruited to a multicenter, randomized factorial trial. Pts received 5-FU (1,000mg/m2/day on d1–4 and 29–32), radiotherapy (RT) (50.4Gy in 28 fractions), and either MMC (12mg/m2, d1; n=471) or CDDP (60mg/m2 on d1 and 29; n=469). Pts were also randomized to receive maintenance therapy (n=448) 4 weeks after CRT (two cycles of CDDP and 5-FU weeks 11 and 14) or no maintenance (n=446). Maintenance randomization was not considered appropriate in 46 pts. Statistical power was ≥80% to detect a difference in the CR rate of 5% (CDDP vs MMC), and 30% reduction in recurrence (maintenance vs no maintenance). Results: Median age 58 yrs; 62% male, 38% female; tumor site - canal (81%), margin (15%); stage T1-T2 (50%), T3-T4 (43%); node negative (62%), positive (30%). Median follow-up was 3 yrs. The CR rate was 94% MMC and 95% CDDP (p=0.53). MMC pts had more acute grade 3/4 haematological toxicities (25 vs 13%, p<0.001) but this did not result in an increase in neutropaenic sepsis (3.1 vs 3.2%, p=0.93). Non-haematologic grade 3/4 toxicities were similar (61 vs 65%, p=0.22). Preliminary analysis shows no statistically significant difference in recurrence free survival (RFS) (HR 0.89, 95% CI 0.68, 1.18; p=0.42) or overall survival (HR 0.79, 95% CI 0.56,1.12; p=0.19) for the maintenance comparison. The number of pre-treatment colostomies not reversed were similar between treatments (18 MMC vs 14 CDDP, p=0.65, Maint/No maint, p=0.23) and only 9 disease-free pts had colostomies performed (5 MMC, 4 CDDP). Conclusions: ACT II is the largest trial conducted in anal cancer. High CR (95%) and RFS (75% at 3 yrs) rates were achieved with this CRT. This excellent outcome may have been influenced by the absence of a gap in the RT schedule. There was no difference in CR rates between MMC and CDDP or in RFS rates with or without maintenance chemotherapy. 5-FU, MMC with RT remains the standard of care.

[Table: see text]

Hypoxia-inducible factor-1alpha and -2alpha are expressed in most rectal cancers but only hypoxia-inducible factor-1alpha is associated with prognosis

The hypoxia-mediated response of tumours is a major determining factor in growth and metastasis. Understanding tumour biology under hypoxic conditions is crucial for the development of antiangiogenic therapy. Using one of the largest cohorts of rectal adenocarcinomas to date, this study investigated hypoxia-inducible factor-1α (HIF-1α) and HIF-2α protein expression in relation to rectal cancer recurrence and cancer-specific survival. Patients (n=90) who had undergone surgery for rectal adenocarcinoma, with no prior neoadjuvant therapy or metastatic disease, and for whom adequate follow-up data were available were selected. Microvessel density (MVD), HIF-1α and HIF-2α expressions were assessed immunohistologically with the CD34 antibody for vessel identification and the NB100-131B and NB100-132D3 antibodies for HIF-1α and HIF-2α, respectively. In a multifactorial analysis, results were correlated with tumour stage, recurrence rate and long-term survival. Microvessel density was higher across T and N stages (P<0.001) and associated with poor survival (hazard ratio (HR)=8.7, P<0.005) and decreased disease-free survival (HR=4.7, P<0.005). hypoxia-inducible factor-1α and -2α were expressed in >50% of rectal cancers (HIF-1α, 54%, 48/90; HIF-2α, 64%, 58/90). HIF-1α positivity was associated with both TNM stage (P<0.05) and vascular invasion (P<0.005). In contrast, no associations were shown between HIF-2α expression and any pathological features, and HIF-1α positivity had no effect on outcome. The study showed an independent association between HIF-1α expression and advanced TNM stage with poor outcome. Our results indicate that HIF-1α, but not HIF-2α, might be used as a marker of prognosis, in addition to methods currently used, to enhance patient management.