Prospective trial of preoperative concomitant boost radiotherapy with continuous infusion 5-fluorouracil for locally advanced rectal cancer

Measurement of the distance between tumor micro-foci and gross tumor in rectal cancer pathological specimens: implication on margin distance of clinical target volume treated with high-dose radiotherapy for rectal cancer

PURPOSE

To measure the micro-foci distance away from gross tumor and to provide reference to create the clinical target volume (CTV) margin for boost radiotherapy in rectal adenocarcinoma.

METHODS

Twenty-eight rectal cancer surgical specimens of only total mesorectal excision were collected. The pathological specimens were retrospectively measured, and the nearest distance between the tumor micro-foci and gross tumor was microscopically measured. The "in vivo-in vitro" retraction factor was calculated as the ratio of the deepest thickness laterally and the vertical height superior/inferiorly of the rectal tumor measured in MRI and those measured in immediate pathological specimens. The retraction factor during pathological specimen processing was calculated as the distance ratio before and after dehydration in the lateral, superior, and inferior sides by the "knot marking method." The distances of tumor micro-foci were individually corrected with these two retraction factors.

RESULTS

The mean "in vivo-in vitro" tumor retraction factors were 0.913 peripherally and 0.920 superior/inferiorly. The mean tumor specimen processing retraction factors were 0.804 peripherally, 0.815 inferiorly, and 0.789 superiorly. Of 28 patients, 14 cases (50.0%) had 24 lateral micro-foci, 8 cases (28.6%) had 13 inferior micro-foci, and 7 cases (25.0%) had 19 superior micro-foci. The 95th percentiles of the micro-foci distance for 28 patients were 6.44 mm (peripheral), 5.54 mm (inferior), and 5.42 mm (superior) after retraction correction.

CONCLUSION

The micro-foci distances of 95% of rectal adenocarcinoma patients examined were within 6.44 mm peripherally, 5.54 mm inferiorly, and 5.42 mm superiorly. These findings provide reference to set the boost radiotherapy CTV margin for rectal cancer.

Long-term effect of neoadjuvant radiotherapy in patients with locally advanced rectal mucinous adenocarcinoma: a population-based study of 1514 patients

Rectal mucinous adenocarcinoma (RMAC) is a rare and aggressive form of rectal cancer. The effectiveness of neoadjuvant radiotherapy (NRT) for RMAC has not been well studied, and the survival benefit remains controversial. The purpose of this work was to determine the prognostic role of NRT in patients with RMAC by propensity-score matching (PSM). A retrospective cohort study using the Surveillance, Epidemiology, and End Results from 2004 to 2015 was performed. In the multivariate analysis before PSM, NRT provided better OS (HR 0.61, 95% CI 0.52-0.71, p < 0.001) and CSS (HR 0.68, 95% CI 0.56-0.82, p < 0.001). Multivariate analysis after PSM (n = 844) confirmed that patients receiving NRT survived longer than those without NRT (OS: HR 0.60, 95% CI 0.50-0.78, p < 0.001 and CSS: HR 0.68, 95% CI 0.54-0.84, p < 0.001). Subgroup analysis indicated that NRT had significantly improved OS and CSS in stage II RMAC and OS in stage III RMAC after adjusting for various confounding factors.

BioXmark® liquid fiducials to enable radiotherapy tumor boosting in rectal cancer, a feasibility trial

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BioXmark® is a novel liquid fiducial marker for image-guided radiotherapy.

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The marker remained stable during chemoradiotherapy in 96% of rectal cancer cases.

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The fiducial allows for image tracking on CT-based imaging modalities.

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Marker visibility was good using CT-based imaging without any relevant artifacts.

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The marker is easy to inject without marker related adverse events.

Background and purpose

Dose-escalation in rectal cancer (RCa) may result in an increased complete response rate and thereby enable omission of surgery and organ preservation. In order to implement dose-escalation, it is crucial to develop a technique that allows for accurate image-guided radiotherapy. The aim of the current study was to determine the performance of a novel liquid fiducial marker (BioXmark®) in RCa patients during the radiotherapy course by assessing its positional stability on daily cone-beam CT (CBCT), technical feasibility, visibility on different imaging modalities and safety.

Materials and methods

Prospective, non-randomized, single-arm feasibility trial with inclusion of twenty patients referred for neoadjuvant chemoradiotherapy for locally advanced RCa. Primary study endpoint was positional stability on CBCT. Furthermore, technical aspects, safety and clinical performance of the marker, such as visibility on different imaging modalities, were evaluated.

Results

Seventy-four markers from twenty patients were available for analysis. The marker was stable in 96% of the cases. One marker showed clinically relevant migration, one marker was lost before start of treatment and one marker was lost during treatment. Marker visibility was good on computed tomography (CT) and CBCT, and moderate on electronic portal imaging (EPI). Marker visibility on magnetic resonance imaging (MRI) was poor during response evaluation.

Conclusion

The novel liquid fiducial marker demonstrated positional stability. We provide evidence of the feasibility of the novel fiducial marker for image-guided radiotherapy on daily cone beam CT for RCa patients.

Locally advanced rectal mucinous adenocarcinoma: is preoperative radiation necessary?

BACKGROUND

Neoadjuvant chemoradiotherapy is recommended for locally advanced rectal cancer, allowing preoperative down-staging of the primary tumor to facilitate complete surgical removal. However, further investigation is warranted for identifying whether radiotherapy is necessary for rectal mucinous adenocarcinoma (RMAC). Thus, this study was designed to explore the relationship between mFOLFOX6 with or without preoperative radiotherapy and therapeutic efficacy in locally advanced RMAC.

METHODS

A total of 81 patients were retrospectively enrolled, with MRI-defined clinical stage II/III RMAC received neoadjuvant treatment with mFOLFOX6 alone (group A) or mFOLFOX6 plus radiation (group B), followed by total mesorectal excision. Tumor down-staging and tumor response were assessed based on post-treatment MRI-defined radiographical and pathological findings. Follow-up data were retrieved, and the Kaplan-Meier curve was used to determine the relationship between the 3-year disease-free survival (DFS) and overall survival (OS) in the two groups.

RESULTS

There were no significant differences in the clinical baseline characteristics of patients between group A and group B. The sphincter preservation rate in group B was 60.9%, higher than in group A (20.0%) (P=0.031). The rate of pathological complete response (pCR) was 14.0% in group B, while no patients had pCR in group A (P=0.029), and the tumor response rate in group B was higher than in group A (52.0% vs. 16.1%, P=0.001). The 3-year probability of OS in group A and B was 77.4% and 72.0% (P=0.509), and 3-year DFS was 58.1% and 56.0% (P=0.592), respectively.

CONCLUSIONS

Neoadjuvant mFOLFOX6-based chemoradiotherapy could be a promising therapeutic option for patients with RMAC, which was associated with a high rate of pCR and sphincter preservation in comparison to treated with mFOLFOX6 alone.

Current approaches in intensification of long-course chemoradiotherapy in locally advanced rectal cancer: a review

Rectal cancer is one of the most prevalent cancers in the world. In many countries, the current standard of care is long-course chemoradiation (CRT), followed by total mesorectal excision. Some efforts have been made by intensifying radiation or chemotherapy components of the neoadjuvant therapy to further decrease the local recurrence and augment surgery’s feasibility and improve the oncological outcomes. This paper reviews recent intensified neoadjuvant interventions in locally advanced rectal cancer (LARC) in terms of efficacy and treatment-related toxicity. Many maneuvers have been made so far to improve the oncological outcomes of rectal cancer with intensified neoadjuvant long-course CRT. Some of these approaches seem compelling and deserve further study, while some have just increased the treatment-related toxicities without evident benefits. Those endeavors with greater pathological complete response than the standard of care may make us await the long-term results on survival rates and chronic treatment-related toxicity. After introduction of neoadjuvant CRT for LARC there have been many efforts to improve its outcomes. Here, this study gathered most of these efforts that intensified the neoadjuvant therapy with some being promising and some being futile.

Planning target volume margin assessment for online adaptive MR-guided dose-escalation in rectal cancer on a 1.5 T MR-Linac

PURPOSE

This study assessed the margins needed to cover tumor intrafraction motion during an MR-guided radiotherapy (MRgRT) dose-escalation strategy in intermediate risk rectal cancer.

METHODS

Fifteen patients with rectal cancer were treated with neoadjuvant short-course radiotherapy, 5x5 Gy, according to an online adaptive workflow on a 1.5 T MR-linac. Per patient, 26 3D T2 weighted MRIs were made; one reference scan preceding treatment and five scans per treatment fraction. The primary tumor was delineated on each scan as gross tumor volume (GTV). Target coverage margins were assessed by isotropically expanding the reference GTV until more than 95% of the voxels of the sequential GTVs were covered. A margin with a coverage probability threshold of 90% was defined as adequate. Intra- and interfraction margins to cope with the movement of the GTV in the period between scans were calculated to indicate the target volume margins. Furthermore, the margin needed to cover GTV movement was calculated for different time intervals.

RESULTS

The required margins to cover inter- and intrafraction GTV motion were 17 mm and 6 mm, respectively. Analysis based on time intervals between scans showed smaller margins were needed for adequate GTV coverage as time intervals became shorter, with a 4 mm margin required for a procedure of 15 min or less.

CONCLUSION

The shorter the treatment time, the smaller the margins needed to cover for the GTV movement during an online adaptive MRgRT dose-escalation strategy for intermediate risk rectal cancer. When time intervals between replanning and the end of dose delivery could be reduced to 15 min, a 4 mm margin would allow adequate target coverage.

Mucinous Adenocarcinoma of the Rectum: A Whole Genome Sequencing Study

Introduction

Mucinous adenocarcinoma of the rectum is an infrequently encountered histological subtype that is associated with an impaired response to chemoradiotherapy and a worse overall prognosis. A genomic profile analysis of mucinous rectal tumors has not yet been performed. The aim of this study was to comprehensively describe the burden of somatic mutations and copy number variation as well as perform mutational signature and microbial analysis of an in-house collected cohort of mucinous adenocarcinoma of the rectum.

Methods

Genomic DNA was extracted from 10 cases of mucinous rectal cancer and matched normal tissue. Whole genome sequencing (WGS) was carried out on these 10 cases and a comprehensive bioinformatic analysis was undertaken.

Results

The average number of SNVs, InDels and SVs in the cohort was 16,600, 1,855, and 120, respectively. A single case was MSI-H. KRAS mutations were found in 70% of cases while TP53 was mutated in only 40% of cases. CNA gain was identified on chromosomes 7, 8, 12, 13, and 20 while CNA loss was found on chromosomes 4, 8, 17, and 18 corresponding to oncogenes and tumor suppressor genes, respectively. Overall mucinous rectal cancers are more likely to be MSI-H and to have KRAS, BRAF, and PIK3CA mutations when compared to rectal adenocarcinoma NOS. Microbial analysis demonstrated an abundance of Fusobacterium nucleatum in tumor samples compared to normal tissue.

Conclusion

This study provides a detailed WGS analysis of 10 cases of mucinous rectal cancer. It demonstrates an important lesson in tumor biology in that histologically similar tumors can have extensive differences at the genomic level. This study is relevant as it raises important questions about the relationship between bacteria and malignancy.

Exploring MR regression patterns in rectal cancer during neoadjuvant radiochemotherapy with daily T2- and diffusion-weighted MRI

Background

To date, only limited magnetic resonance imaging (MRI) data are available concerning tumor regression during neoadjuvant radiochemotherapy (RCT) of rectal cancer patients, which is a prerequisite for adaptive radiotherapy (RT) concepts. This exploratory study prospectively evaluated daily fractional MRI during neoadjuvant treatment to analyze the predictive value of MR biomarkers for treatment response.

Methods

Locally advanced rectal cancer patients were examined with daily MRI during neoadjuvant RCT. Contouring of the tumor volume was performed for each MRI scan by using T2- and diffusion-weighted-imaging (DWI)-sequences. The daily apparent-diffusion coefficient (ADC) was calculated. Volumetric and functional tumor changes during RCT were analyzed and correlated with the pathological response after surgical resection.

Results

In total, 171 MRI scans of eight patients were analyzed regarding anatomical and functional dynamics during RCT. Pathological complete response (pCR) could be achieved in four patients, and four patients had a pathological partial response (pPR) following neoadjuvant treatment. T2- and DWI-based volumetry proved to be statistically significant in terms of therapeutic response, and volumetric thresholds at week two and week four during RCT were defined for the prediction of pCR. In contrast, the average tumor ADC values widely overlapped between both response groups during RCT and appeared inadequate to predict treatment response in our patient cohort.

Conclusion

This prospective exploratory study supports the hypothesis that MRI may be able to predict pCR of rectal cancers early during neoadjuvant RCT. Our data therefore provide a useful template to tailor future MR-guided adaptive treatment concepts.

MRI-based tumor inter-fraction motion statistics for rectal cancer boost radiotherapy

BACKGROUND

In patients diagnosed with rectal cancer, dose escalation is currently being investigated in a large number of studies. Since there is little known on gross tumor volume (GTV) inter-fraction motion for rectal cancer, a wide variety in margins is used. Purpose of this study is to quantify GTV inter-fraction motion statistics on different timescales and to give estimates of planning target volume (PTV) margins.

MATERIAL AND METHODS

Thirty-two patients, diagnosed with rectal cancer, were included. To investigate motion from week-to-week, 16 patients underwent a pretreatment and five weekly MRIs, prior to a radiotherapy (RT) fraction of the chemoradiotherapy treatment. To investigate motion from day-to-day, the remaining 16 patients underwent five daily MRIs before each fraction in one week of RT. GTV was delineated on all scans according to guidelines. Scans were aligned on bony anatomy with the first MRI. For both datasets separately, GTV inter-fraction motion was determined based on center-of-gravity displacement. Therefrom, systematic and random errors were determined in left/right (LR), anterior/posterior and cranial/caudal (CC) direction. PTV margin estimates were calculated and evaluated on GTV coverage.

RESULTS

Systematic and random errors were found in the range of 2.3-4.8 mm and 1.5-3.3 mm from week-to-week, and 1.8-4.5 mm and 1.8-4.0 mm from day-to-day, respectively. On both timescales, similar motion patterns were found; the most motion was observed in CC whilst the least motion was observed in LR. On the week-to-week data more systematic and less random motion was observed compared to the day-to-day data. Overall, only slight differences in margin estimates were found. Derived PTV margin estimates were found to give adequate GTV coverage.

CONCLUSION

GTV inter-fraction motion, on a week-to-week and day-to-day timescale, can be accounted for using motion statistics presented in this study.

Non-operative management of rectal cancer: understanding tumor biology

The management of locally-advanced rectal cancer involves a combination of chemotherapy, chemoradiation, and surgical resection to provide excellent local tumor control and overall survival. However, aspects of this multimodality approach are associated with significant morbidity and long-term sequelae. In addition, there is growing evidence that patients with a clinical complete response to chemotherapy and chemoradiation treatments may be safely offered initial non-operative management in a rigorous surveillance program. Weighed against the morbidity and significant sequelae of rectal resection, recognizing how to best optimize non-operative strategies without compromising oncologic outcomes is critical to our understanding and treatment of this disease.

Preoperative Concomitant Radiochemotherapy with A 5-Fluorouracil plus Folinic Acid Bolus in the Combined Treatment of Locally Advanced Extraperitoneal Rectal Cancer: A Long-Term Analysis on 27 Patients

Aims and background

Many studies of preoperative chemoradiation in resectable rectal cancer have focused on downstaging and sphincter-saving procedures. The aim of this study was to evaluate long-term outcome in resectable rectal cancer treated with preoperative chemoradiation and surgery by only one surgical team irrespective of the tumor downstaging.

Material and methods

From 1992 to 2001, in a cooperative study between the Institute of Semeiotica Chirurgica and the Division of Radiotherapy of the Catholic University of the Sacred Heart, 27 patients with locally advanced rectal cancer were treated with preoperative chemoradiation, followed by surgery after 4-6 weeks, and, just for 6 of them, by adjuvant chemotherapy. Seventeen patients were staged T3 N1 (63%), 4 patients T3N0 (15%), 4 patients T3N2 (15%) and 2 T4N2 (7.5%). Twenty-three patients (85.1%) had signs of nodal involvement at combined imaging. Radiation therapy was delivered to the posterior pelvis at a dose of 45 Gy to the tumor (clinical target volume) and the whole pelvis (planning target volume). Fractionation was conventional: 1.8 Gy/day, 5 fractions a week. Radiotherapy was started on Monday for all patients and was delivered with a linear accelerator. Concomitant chemotherapy consisted of 5-fluorouracil (350 mg/m2/day, as an intravenous bolus on days 1-5 and 29-33 of radiotherapy) and folinic acid (L-isomer) (10 mg/m2 as an intravenous bolus on days 1-5 and 29-33). This chemotherapy was generally administered about 1 hr before radiotherapy. Data were analyzed on July 2002; median follow-up was 59 months (range, 20-116 months). No patient was lost during the follow-up.

Results

All patients completed the treatment. Grade >3 acute toxicity occurred in 11% of the patients and late toxicity was 15%. A pathologic complete response was recorded in 22% of patients; sphincter-preserving surgery was feasible in 44%. Seven patients died: 2 of them perioperatively, 1 patient died with local recurrence, and 1 died with distant metastases; 3 patients died during the follow-up for other causes. Five-year local control was 95% and overall survival was 84%.

Conclusions

Our study, although limited in number, demonstrated good results in local control and disease-free survival with a limited toxicity.

Concurrent Boost Radiotherapy as Preoperative Treatment for Locally Advanced Rectal Carcinoma: A New Beam Arrangement

Purpose

To describe a new beam arrangement for preoperative concurrent boost radiotherapy in locally advanced rectal carcinoma.

Material and methods

Three different volumes, ie posterior pelvis, total mesorectal space, and gross tumor volume plus 2 cm, are selected to receive radiation doses of 47 Gy, 51 Gy, and 54 Gy, respectively, in 24 fractions. There are two prerequisites for the use of such a radiotherapy schedule: complete displacement of the small bowel outside the boost volume, and horizontal positioning of the rectal long axis. Both conditions can be attained by patient positioning on a new device, the “Up-Down Table” (UDT). The dose gradient between the three volumes is realized with two daily arc rotation fields with an isocenter that is different from the three additional multileaf collimator pelvic fields (postero-anterior + 2 laterolateral).

Results

The treatment data are reported according to the ICRU 62 criteria. A comparison was made between concurrent arc rotation and concomitant static boost techniques.

Conclusion

The new beam arrangement, with the use of the UDT, allows to administer different radiation doses to three volumes with different tumor cell density in order to obtain the same probability of local response in all target volumes without increasing the toxicity.

Long-term Effect of Radiotherapy in Rectal Cancer Patients with Mucinous Tumor: A Large Population Based Study

Due to distinct biological behavior of mucinous adenocarcinoma (MAC) and signet ring cell cancer (SRC), the efficacy of radiotherapy on long-term outcome for rectal cancer (RC) patients with mucinous tumors is still unclear. Here, we identified 1808 RC patients with MAC/SRC from Surveillance, Epidemiology, and End-Results (SEER) database from 2004 to 2013. Patients were divided into two subgroups according to different therapeutic strategies, including surgery alone and surgery combined with radiotherapy. Kaplan–Meier methods and Cox regression models were used to access the influence of therapeutic strategy on long-term survival outcomes. The 5-year and 10-year cancer specific survival (CSS) were improved in stage II and III patients who underwent surgery and radiotherapy compared with patients who underwent surgery alone. These results were further confirmed following propensity score matching. In addition, radiotherapy was deemed as independent good prognostic factor in patient with MAC/SRC. In subgroup analysis, the result also demonstrated that long-term survival was improved following radiotherapy. However, there was no prognostic difference between preoperative and postoperative radiotherapy. In conclusion, radiotherapy could improve survival for RC patients with MAC and SRC, but only for patients in stage II and III. This finding supported the application of radiotherapy in clinical practice.

Mucinous Rectal Adenocarcinoma Is Associated with a Poor Response to Neoadjuvant Chemoradiotherapy: A Systematic Review and Meta-analysis

BACKGROUND

Mucinous adenocarcinoma represents a potentially poor prognostic subgroup of rectal cancer. A consensus on the effect of mucinous cancer on outcomes following neoadjuvant chemoradiotherapy and curative resection for rectal cancer has not been reached.

OBJECTIVE

The aim of the current study is to use meta-analytical techniques to assess the association between mucinous histology and response to neoadjuvant chemoradiotherapy in rectal cancer.

DATA SOURCES

A comprehensive literature search of PubMed, Embase, and The Cochrane Library was performed.

STUDY SELECTION

All studies examining the effect of mucinous histology on chemotherapeutic response in rectal cancer were included.

INTERVENTIONS

No direct interventions were performed.

MAIN OUTCOME MEASURES

Outcomes of mucinous rectal adenocarcinoma were compared with nonmucinous tumors by using random-effects methods to analyze data. Data are presented as ORs with 95% CIs. The main outcomes measured were the rates of pathological complete response, tumor and nodal downstaging, positive resection margin rate, local recurrence, and overall mortality.

RESULTS

Eight comparative series describing outcomes in 1724 patients were identified, 241 had mucinous tumors (14%). Mucinous tumors had a reduced rate of pathological complete response (OR, 0.078; 95% CI, 0.015-0.397; p = 0.002) and tumor downstaging (OR, 0.318; 95% CI, 0.185-0.547; p < 0.001) following neoadjuvant chemoradiotherapy with an increased rate of positive resection margin (OR, 5.018; 95% CI, 3.224-7.810; p < 0.001) and poorer overall survival (OR, 1.526; 95% CI, 1.060-2.198; p = 0.023) following resection. Mucin expression did not significantly affect nodal downstaging (OR, 0.706; 95% CI, 0.295-1.693; p = 0.435) or local recurrence (OR, 1.856; 95% CI, 0.933-3.693; p = 0.078). There was no across-study heterogeneity for any end point.

LIMITATIONS

Most studies were retrospectively designed, and there were variations in patient populations and duration of follow-up.

CONCLUSIONS

Mucinous rectal adenocarcinoma represents a biomarker for poor response to preoperative chemoradiotherapy and is an adverse prognostic indicator.

Effect of Neoadjuvant Chemoradiotherapy with Capecitabine versus Fluorouracil for Locally Advanced Rectal Cancer: A Meta-Analysis

A meta-analysis was carried out to compare the efficacy and safety of capecitabine plus radiation with 5-fluorouracil (5-FU) plus radiotherapy (RT) as neoadjuvant treatment in locally advanced rectal cancer (LARC). We searched the Cochrane database, Ovid, Medline, Embase, ISI databases, and Chinese Biomedical Literature Database between January 1998 and October 2014. Trials of capecitabine compared with 5-FU plus RT as neoadjuvant treatment for LARC were considered for inclusion. RevMan software was used to analyze these data. Nine trials were included in this meta-analysis, which covered a total of 3141 patients. The meta-analysis showed that capecitabine group had statistically significant better pCR rates (OR, 1.34; 95% CI, 1.10-1.64; P = 0.003), T downstaging rates (OR, 1.58; 95% CI, 1.22-2.06; P = 0.0007), N downstaging rates (OR, 2.06; 95% CI, 1.34-3.16; P = 0.001), less distant metastasis (OR, 0.63; 95% CI, 0.44-0.88; P = 0.007), and lowered leucocytes (OR, 0.25; 95% CI, 0.11-0.54; P = 0.0005), but with higher incidence of hand-foot syndrome (HFS) (OR, 4.43; 95% CI, 1.59-12.33; P = 0.004). Capecitabine was more efficient than 5-FU in terms of tumor response in neoadjuvant treatment for patients with LARC and favourably low toxicity with the exception of HFS.

Risk factors for wound complications in patients undergoing primary closure of the perineal defect after total proctectomy

PURPOSE

Perineal wounds after complete proctectomy are at risk for failure, with dramatic consequences on patients' health and quality of life. This study is aimed at identifying risk factors for wound complications in patients undergoing primary closure of the perineal defect after total proctectomy.

METHODS

Data from 284 patients undergoing total proctectomy from 2002 to 2012 either at the University of Chicago Medical Center or the Catholic University of Rome Hospital were collected and analyzed.

RESULTS

Overall, the perineal wound complication rate was 21.8%. Successful conservative management was accomplished in 45.2% of cases. Complications occurred significantly more often in patients with a higher Charlson score index, with the diagnosis of rectal cancer, who had received preoperative radiation and who had a surgical drain placed at the time of initial surgery. Neoadjuvant radiation was the only significant risk factor at multivariate analysis (OR 4.40). In the rectal cancer subgroup, younger age, female gender, and preoperative radiation were predictors of wound complications. Based on that, a 3-point score (radiation, age, and gender (RAG)) was developed. Patients with a score of 3 had a 50% risk of developing a perineal wound complication.

CONCLUSIONS

Perineal wound complications are a common and burdensome problem after total proctectomy. Preoperative radiation is the single most significant and controllable risk factor predicting perineal wound failure. In the presence of multiple, non-modifiable risk factors, alternative approaches to primary closure should be considered in managing complex perineal defects.

Impact of radiotherapy boost on pathological complete response in patients with locally advanced rectal cancer: a systematic review and meta-analysis

PURPOSE

We conducted a systematic review and meta-analysis to quantify the pathological complete response (pCR) rate after preoperative (chemo)radiation with doses of ⩾60Gy in patients with locally advanced rectal cancer. Complete response is relevant since this could select a proportion of patients for which organ-preserving strategies might be possible. Furthermore, we investigated correlations between EQD2 dose and pCR-rate, toxicity or resectability, and additionally between pCR-rate and chemotherapy, boost-approach or surgical-interval.

METHODS AND MATERIALS

PubMed, EMBASE and Cochrane libraries were searched with the terms 'radiotherapy', 'boost' and 'rectal cancer' and synonym terms. Studies delivering a preoperative dose of ⩾60 Gy were eligible for inclusion. Original English full texts that allowed intention-to-treat pCR-rate calculation were included. Study variables, including pCR, acute grade ⩾3 toxicity and resectability-rate, were extracted by two authors independently. Eligibility for meta-analysis was assessed by critical appraisal. Heterogeneity and pooled estimates were calculated for all three outcomes. Pearson correlation coefficients were calculated between the variables mentioned earlier.

RESULTS

The search identified 3377 original articles, of which 18 met our inclusion criteria (1106 patients). Fourteen studies were included for meta-analysis (487 patients treated with ⩾60 Gy). pCR-rate ranged between 0.0% and 44.4%. Toxicity ranged between 1.3% and 43.8% and resectability-rate between 34.0% and 100%. Pooled pCR-rate was 20.4% (95% CI 16.8-24.5%), with low heterogeneity (I2 0.0%, 95% CI 0.00-84.0%). Pooled acute grade ⩾3 toxicity was 10.3% (95% CI 5.4-18.6%) and pooled resectability-rate was 89.5% (95% CI 78.2-95.3%).

CONCLUSION

Dose escalation above 60 Gy for locally advanced rectal cancer results in high pCR-rates and acceptable early toxicity. This observation needs to be further investigated within larger randomized controlled phase 3 trials in the future.

The effects of hyperbaric oxygen therapy on experimental colon anastomosis after preoperative chemoradiotherapy

The aim of the present study was to investigate the effect of hyperbaric oxygen therapy (HBOT) on colon anastomosis after chemoradiotherapy (CRT). Sixty female Wistar-Albino rats were divided into 5 groups and underwent left colon resection and end-to-end anastomosis. CRT simulation was performed on 2 sham groups before the anastomosis, and 1 of these groups was administered additional postoperative HBOT. Two groups were administered CRT before the anastomosis, and 1 of them received additional postoperative HBOT. On postoperative day 5, all groups underwent relaparotomy; burst pressure was measured and samples were obtained for histopathologic and biochemical analysis. There was a significant weight loss in the CRT groups and postoperative HBOT had an improving effect. Significantly decreased burst pressure values increased up to the levels of the controls after HBOT. Hydroxyproline levels were elevated in all groups compared to the control group. Hydroxyproline levels decreased with HBOT after CRT. No significant difference was observed between the groups regarding fibrosis formation at the anastomosis site. However, regression was observed in fibrosis in the group receiving HBOT after CRT. Preoperative CRT affected anastomosis and wound healing unfavorably. These unfavorable effects were alleviated by postoperative HBOT. HBOT improved the mechanical and biochemical parameters of colon anastomosis in rats.

The role of perfusion effects in monitoring of chemoradiotherapy of rectal carcinoma using diffusion-weighted imaging

PURPOSE

The aim of this study was to characterize and understand the therapy-induced changes in diffusion parameters in rectal carcinoma under chemoradiotherapy (CRT). The current literature shows conflicting results in this regard. We applied the intravoxel incoherent motion model, which allows for the differentiation between diffusion (D) and perfusion (f) effects, to further elucidate potential underlying causes for these divergent reports.

MATERIALS AND METHODS

Eighteen patients with primary rectal carcinoma undergoing preoperative CRT were examined before, during, and after neoadjuvant CRT using diffusion-weighted imaging. Using the intravoxel incoherent motion approach, f and D were extracted and compared with postoperative tumor downstaging and volume.

RESULTS

Initial diffusion-derived parameters were within a narrow range (D1 = 0.94 ± 0.12 × 10(-3) mm(2)/s). At follow-up, D rose significantly (D2 = 1.18 ± 0.13 × 10(-3) mm(2)/s; P < 0.0001) and continued to increase significantly after CRT (D3 = 1.24 ± 0.14 × 10(-3) mm(2)/s; P < 0.0001). The perfusion fraction f did not change significantly (f1 = 9.4 ± 2.0%, f2 = 9.4 ± 1.7%, f3 = 9.5 ± 2.7%). Mean volume (V) decreased significantly (V1 = 16,992 ± 13,083 mm(3); V2 = 12,793 ± 8317 mm(3), V3 = 9718 ± 6154 mm(3)). T-downstaging (10:18 patients) showed no significant correlation with diffusion-derived parameters.

CONCLUSIONS

Conflicting results in the literature considering apparent diffusion coefficient (ADC) changes in rectal carcinoma under CRT for patients showing T-downstaging are unlikely to be due to perfusion effects. Our data support the view that under effective therapy, an increase in D/ADC can be observed.

Gangrene of the penis, scrotum, and perineum, occurred after radiotherapy of rectal cancer

We present a case of a 58-year-old man hospitalized because of gangrene of the penis and scrotum, after radiochemotherapy for rectal cancer. At the time of the admission the patient presented with extensive gangrene with necrosis affecting the scrotum and the penis. During the first day of hospitalization the patient was operated. Due to the progress of the disease he had to be operated again. The status of the patient, which initially was very bad, was gradually improving. He was discharged from the hospital after 59 days in a good general state with good wound healing.

How reliable is current imaging in restaging rectal cancer after neoadjuvant therapy?

In patients with advanced rectal cancer, neoadjuvant chemo radiotherapy provides tumor downstaging and downsizing and complete pathological response in up to 30% of cases. After proctectomy complete pathological response is associated with low rates of local recurrence and excellent long term survival. Several authors claim a less invasive surgery or a non operative policy in patients with partial or clinical complete response respectively, however to identify patients with true complete pathological response before surgical resection remains a challenge. Current imaging techniques have been reported to be highly accurate in the primary staging of rectal cancer, however neoadjuvant therapy course produces deep modifications on cancer tissue and on surrounding structures such as overgrowth fibrosis, deep stroma alteration, wall thickness, muscle disarrangement, tumor necrosis, calcification, and inflammatory infiltration. As a result, the same imaging techniques, when used for restaging, are far less accurate. Local tumor extent may be overestimated or underestimated. The diagnostic accuracy of clinical examination, rectal ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography using 18F-fluoro-2’-deoxy-D-glucose ranges between 25% and 75% being less than 60% in most studies, both for rectal wall invasion and for lymph nodes involvement. In particular the ability to predict complete pathological response, in order to tailor the surgical approach, remains low. Due to the radio-induced tissue modifications, combined with imaging technical aspects, low rate accuracy is achieved, making modern imaging techniques still unreliable in restaging rectal cancer after chemo-radiotherapy.

New application of dual point 18F-FDG PET/CT in the evaluation of neoadjuvant chemoradiation response of locally advanced rectal cancer

PURPOSE

FDG PET/CT has been suggested as the most reliable modality to predict pathological tumor responses after neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC). However, several confounding factors including radiation-induced inflammation could not be easily avoided with the commonly used single-point FDG PET/CT. Our aim was to evaluate the accuracy of a dual-point PET/CT protocol in LARC response prediction to CRT.

PATIENTS AND METHODS

Sixty-one LARC patients were enrolled and treated with neoadjuvant CRT. PET/CT was performed before and after CRT. Dual-point acquisition was applied to post-CRT PET/CT. Post-CRT SUVmax (postSUV), pre/post-CRT SUVmax change (RI), and dual-point index (DI) of post-CRT PET/CT were compared with the Dworak tumor regression grade (TRG) as a gold standard. Univariate and multivariate analyses, as well as receiver operating characteristic curve analysis, were used to evaluate the predictive ability of demographic, clinical, and metabolic PET parameters.

RESULTS

Fifteen patients of TRG3-4 were defined as pathological responders, and 46 patients of TRG1-2 were nonresponders. The resulting response index (RI) ranged from -13 to 94.8% (59.1±22.0%), and delay index (DI) ranged from -45.2 to 25.0% (-9.1±12.1%). Univariate analysis resulted in PET parameters (postSUV, RI, and DI) as significant predictors (P=0.004, P<0.001, P<0.0001). According to multivariate analysis, RI and DI remained as significant predictors (P=0.04 and P=0.0004). Receiver operating characteristic analysis showed that DI had significantly higher area under the curve compared with RI (0.906 vs 0.696, P=0.018). Delay index had 86.7% sensitivity, 87.0% specificity, 68.4% positive predictive value, 95.2% negative predictive value, and 86.9% accuracy.

CONCLUSIONS

Dual-point post-CRT PET/CT can predict pathological tumor response better than conventional single time point pre- and post-CRT PET/CT.

Organ-preserving therapy for rectal cancer

SUMMARY Total mesorectal excision has resulted in low local recurrence rates in rectal cancer patients; however, it is associated with a significant impairment in quality of life. The operation may be disfiguring and cause permanent effects on gastrointestinal, genitourinary and sexual function. Recently, researchers have identified subgroups of rectal cancer patients who may be able to forgo total mesorectal excision without compromising their oncological outcomes. Two groups of patients are candidates for organ preservation: those with early-stage disease that may be adequately addressed by a more limited resection, and those with locally advanced disease that has responded completely to neoadjuvant therapy. Additionally, radiation alone may be curative in both early and locally advanced disease. This article reviews the data regarding these approaches.

Management of local rectal cancer: evidence, controversies and future perspectives in radiotherapy

SUMMARY Rectal cancer comprises approximately 25% of all primary colorectal cancers. The optimal diagnostic and treatment approach for this heterogeneous malignancy is still contentious, and improvements in general multidisciplinary management are required. During recent years a number of randomized studies led by European investigators have shown optimization in preoperative staging, improvements in surgical technique and the histopathological assessment of the resected specimen, and the benefit of combined modality treatment. The main recommendations and the trends in research on radiotherapy and integrated treatments will be summarized with an overview on some relevant points about imaging and pathological staging.

Criteria for three-dimensional anorectal ultrasound assessment of response to chemoradiotherapy in rectal cancer patients

AIM

The aim of this study was to identify criteria for three-dimensional anorectal ultrasonography (3D-AUS) to assess the response of rectal cancer to chemoradiotherapy; the 3D-AUS results were compared with the histopathological findings of the resected specimen.

METHOD

Thirty-five patients underwent 3D-AUS and were grouped according to the presence (GI; n = 19) or absence (GII; n = 16) of anal canal invasion. All patients received chemoradiotherapy, then underwent a second 3D-AUS. The response (complete, partial or insignificant and lymph node metastasis) was evaluated. Tumour length (cm) and volume (cm(3) ), length and volume regression percentage (%), distal length regression, and distance between the distal tumour edge and the proximal border of the internal anal sphincter were measured before and after chemoradiotherapy. All patients underwent surgery, and the 3D-AUS image was compared with the histopathological findings.

RESULTS

Before chemoradiotherapy, the average tumour length was similar in G1 and GII, but the volume differed significantly (P = 0.0408). The response was insignificant in seven (37%) patients, partial in 10 (53%) patients and complete in two (10%) patients in GI. The corresponding figures for GII were one (6%) patient, 12 (75%) patients and three (19%) patients (P = 0.0318). The agreement between pathological and post-chemoratherapy 3D-AUS findings was almost identical for the identification of residual tumour or complete response (κ = 1.0) and substantial for lymph node metastases (κ = 0.74). The mean distance to the internal anal sphincter was greater in GII. A sphincter-saving resection was performed in 2/19 patients in GI and in 14/16 patients in GII (P < 0.0001). The histopathological examination revealed a free distal margin.

CONCLUSION

3D-AUS was shown to evaluate accurately the response to chemoradiotherapy, helping in the selection of patients for a sphincter-saving resection. The distance between the tumour and the internal anal sphincter was the most important parameter in this respect.

Locally advanced rectal cancer: a comparison of management strategies

Traditionally, there has been a high local recurrence rate in rectal cancer and 10-40% of patients require a permanent stoma. Both short-course preoperative radiotherapy (SCPRT) and long-course preoperative chemoradiation (CRT) are used to reduce the risk of local recurrence and enable a curative resection. Total mesorectal excision has reduced the rate of local recurrence (even without radiotherapy) to below 10%, but has highlighted a high risk of metastatic disease in 30-40% of patients. Current trials suggest that in resectable cancers, where the preoperative magnetic resonance imaging (MRI) suggests the circumferential resection margin (CRM) is not potentially involved, then SCPRT and CRT are equivalent in terms of outcomes such as local recurrence, disease-free survival (DFS) and overall survival (OS). For patients with more advanced disease, where the CRM is breached or threatened according to the MRI, the integration of more active chemotherapy and biological agents into chemoradiation is an attractive strategy because of the high risk of metastases. However, in none of the trials published in the last decade has chemoradiation impacted on DFS or OS. We examine the strategies of neoadjuvant, concurrent, consolidation (after chemoradiation and before surgery) and postoperative adjuvant chemotherapy with cytotoxic agents, and the integration of biological agents for future potential strategies of treatment. We also compare the trials and compare the different strategies of long-course preoperative radiotherapy and SCPRT; the intensification of preoperative radiation and chemoradiation with dose escalation of external beam radiotherapy, using brachytherapy, intra-operative radiotherapy, hyperfractionation, and various available techniques such as intensity-modulated radiotherapy. We recommend examining dose escalation of radiotherapy to the primary tumour where MRI predicts a threatened CRM. Of the potential treatment strategies involving cytotoxic agents, such as neoadjuvant, concurrent, consolidation and postoperative adjuvant chemotherapy, the most promising would appear to be consolidation chemotherapy following chemoradiation in locally advanced disease, and neoadjuvant chemotherapy in MRI-selected patients who do not require radiation. Improvement in the quality of surgery is also an important future goal.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Mucinous rectal cancer: effectiveness of preoperative chemoradiotherapy and prognosis

BACKGROUND

This study investigated the effects of preoperative chemoradiotherapy (PCRT) and the prognoses of patients with mucinous rectal cancer compared with those with nonmucinous cancer.

METHODS

We retrospectively reviewed the medical records of 368 patients who underwent curative resection after PCRT, between 2000 and 2006, for midrectal to lower-rectal adenocarcinoma. Mucinous cancers were present in 23 patients (6.3%) and nonmucinous cancers in 345. In each patient, clinical stage before chemoradiotherapy was compared with pathologic stage to evaluate the extent of downstaging. Survival and multivariate analyses were performed using clinicopathologic variables. The median follow-up period was 42 months (range, 4-105 months).

RESULTS

There was no difference in clinical stage between the groups. Although 58 patients (16.8%) in the nonmucinous group achieved pathologic complete responses (pCR), no mucinous group patient showed such a response. T-downstaging was more frequently observed in the nonmucinous than in the mucinous group (189 vs 7 [54.9% vs 30.4%], P = .03), but N-downstaging was similar in the 2 groups. The 5-year overall survival rate (OS) was significantly lower in the mucinous than in the nonmucinous group (64.8% vs 79.8%, P = .049). Multivariate analysis revealed that mucinous histotype was an independent (negative) prognostic factor for survival (hazard ratio, 2.36; 95% confidence interval, 1.05-5.3; P = .04).

CONCLUSIONS

Patients with mucinous rectal cancer experienced a lower rate of T-downstaging after PCRT and had a poorer prognosis than did patients with nonmucinous cancer.

Multivisceral resection for primary locally advanced rectal carcinoma

BACKGROUND

Pelvic multivisceral resection offers the possibility of cure in patients with locally advanced rectal cancer. This study assessed the clinical outcome and determinants of survival and local recurrence in patients undergoing multivisceral resection for clinical T4 primary rectal cancer.

METHODS

This was a cohort study of consecutive multivisceral resections carried out in a single centre from 2000 to 2009. Determinants of local recurrence and survival were examined by means of Kaplan-Meier survival curves and Cox regression analysis.

RESULTS

The study included 42 patients, with a median age of 62 (range 41-83) years, who underwent surgery with a median follow-up of 30 (range 2-102) months. Thirty-one patients had preoperative chemoradiotherapy. Seven patients had rectal resection with en bloc radical prostatectomy. The 30-day mortality rate was zero. Thirty-nine of the 42 patients had a negative circumferential resection margin. The 5-year overall survival rate for those who had complete resection was 48 per cent. Local recurrence was predicted by metastatic disease (P < 0.001) and nodal disease (P < 0.001), but not positive resection margins (P = 0.077).

CONCLUSION

An aggressive surgical strategy with complete resection is predictive of long-term survival in selected patients with T4a rectal carcinoma. With optimal treatment local recurrence is a sign of systemic disease.

Rectal cancer radiotherapy: towards European consensus

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Accuracy of endoscopic ultrasound to diagnose nodal invasion by rectal cancers: a meta-analysis and systematic review

BACKGROUND

Nodal staging in patients with rectal cancer predicts prognosis and directs therapy. Published data on the accuracy of endoscopic ultrasound (EUS) for diagnosing nodal invasion in patients with rectal cancer has been inconsistent.

AIM

To evaluate the accuracy of EUS in diagnosing nodal metastasis of rectal cancers.

METHOD

Study Selection Criteria: Only EUS studies confirmed by surgical histology were selected. Data Collection and Extraction: Articles were searched in Medline, Pubmed, and CENTRAL.

STATISTICAL METHOD

Pooling was conducted by both fixed-effects model and random-effects model.

RESULTS

The initial search identified 3610 reference articles in which 352 relevant articles were selected and reviewed. Data were extracted from 35 studies (N = 2732) that met the inclusion criteria. Pooled sensitivity of EUS in diagnosing nodal involvement by rectal cancers was 73.2% (95% confidence interval [95% CI] 70.6-75.6). EUS had a pooled specificity of 75.8% (95% CI 73.5-78.0). The positive likelihood ratio of EUS was 2.84 (95% CI 2.16-3.72), and negative likelihood ratio was 0.42 (95% CI 0.33-0.52). All the pooled estimates, calculated by fixed- and random-effect models, were similar. SROC curves showed an area under the curve of 0.79. The P for chi-squared heterogeneity for all the pooled accuracy estimates was >.10.

CONCLUSIONS

EUS is an important and accurate diagnostic tool for evaluating nodal metastasis of rectal cancers. This meta-analysis shows that the sensitivity and specificity of EUS is moderate. Further refinement in EUS technologies and diagnostic criteria are needed to improve the diagnostic accuracy.

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

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSION

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

Adjuvant therapy for rectal cancer

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

Phase I trial of preoperative hypofractionated intensity-modulated radiotherapy with incorporated boost and oral capecitabine in locally advanced rectal cancer

PURPOSE

To determine the safety and efficacy of preoperative hypofractionated radiotherapy using intensity-modulated radiotherapy (IMRT) and an incorporated boost with concurrent capecitabine in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

The eligibility criteria included adenocarcinoma of the rectum, T3-T4 and/or N1-N2 disease, performance status 0 or 1, and age > or =18 years. Photon IMRT and an incorporated boost were used to treat the whole pelvis to 45 Gy and the gross tumor volume plus 2 cm to 55 Gy in 25 treatments within 5 weeks. The study was designed to escalate the dose to the gross tumor volume in 5-Gy increments in 3-patient cohorts. Capecitabine was given orally 825 mg/m(2) twice daily for 7 days each week during RT. The primary endpoint was the maximal tolerated radiation dose, and the secondary endpoints were the pathologic response and quality of life.

RESULTS

Eight patients completed RT at the initial dose level of 55 Gy. The study was discontinued because of toxicity-six Grade 3 toxicities occurred in 3 (38%) of 8 patients. All patients went on to definitive surgical resection, and no patient had a pathologically complete response.

CONCLUSION

This regimen, using hypofractionated RT with an incorporated boost, had unacceptable toxicity despite using standard doses of capecitabine and IMRT. Additional research is needed to determine whether IMRT is able to reduce the side effects during and after pelvic RT with conventional dose fractionation.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSION

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

Phase II Trial of Preoperative Chemoradiation With a Hyperfractionated Radiation Boost in Locally Advanced Rectal Cancer

PURPOSE

The purpose of this phase II study was to prospectively determine the efficacy of preoperative chemoradiation with a hyperfractionated (Hfx) RT boost to 61.8 Gy in locally advanced rectal cancer.

METHODS

Eligibility stipulated that the primary lesion had to be either T4; or T3 and >4 cm or 40% of the bowel circumference. Radiation (RT) consisted of 45 Gy to the pelvis (1.8 Gy per fraction) followed by 1.2 Gy twice daily (to the gross tumor volume) to a total RT dose of 61.8 Gy. There was 5-FU infused at 1 g/m2/24 hours for 4 days during the 1st and 6th weeks of RT (concurrent with the Hfx boost). Surgical resection was planned 4 to 6 weeks later. Adjuvant chemotherapy (bolus 5-FU/leucovorin) was scheduled for 4 cycles at 28-day intervals.

RESULTS

There were 22 patients, ages 22 to 81 years (median, 64) enrolled in the study. Of the 20 patients evaluable for response, 10 (50%) had evidence of clinical downstaging and 5 patients (25%) had > or =90% fibrosis in the resected specimen. With a median f/u of 40 months (7-158), the 4 years actuarial rate for all patients (n = 22) of OS was 64%, of DFS 62%, and of LC 84%. 3/21 patients (14%) had positive margins, all of whom developed a local failure (P < 0.001).

CONCLUSION

This regimen of high dose preoperative chemoRT with a Hfx RT boost (to 61.8 Gy) in patients with bulky, locally advanced rectal cancer results in clinical downstaging in half of the patients with significant fibrosis in the operative specimen.

Long-term prognostic value of 18F-FDG PET in patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy

OBJECTIVE

The purpose of this study was to assess the prognostic value of (18)F-FDG PET performed at restaging in patients with locally advanced rectal cancer who previously underwent neoadjuvant radiochemotherapy.

SUBJECTS AND METHODS

Eighty-eight patients with histologically proven rectal cancer classified at clinical TNM stages II and III were enrolled. Six weeks after radiochemotherapy completion, all patients were restaged by sonography, CT, MRI, endoscopy, and (18)F-FDG PET. Surgery was performed in all patients within 8-9 weeks from completion of radiochemotherapy. Median follow-up after surgery was 38 months (range, 6-66 months).

RESULTS

The 5-year overall survival and disease-free survival were 83% and 73%, respectively. Cox multivariate analysis showed that only two parameters at restaging were independent prognostic predictors of both overall survival and disease-free survival: pathologic stage and, especially, after radiochemotherapy (18)F-FDG PET findings. The 5-year overall survival was 91% in patients with a negative PET after radiochemotherapy versus 72% in those with a positive PET (p = 0.024) after radiochemotherapy, whereas disease-free survival was 81% and 62% (p = 0.003) for those with the negative and positive PET findings, respectively. Statistical data were further enhanced when combining the pathologic stage with the (18)F-FDG PET results: 95% 5-year overall survival in the PET-negative pathologic stages 0 and I patients versus 70% in PET-positive pathologic stages II-IV patients (p = 0.001), whereas disease-free survival was 93% and 65% (p = 0.0003) for the negative and positive PETs, respectively.

CONCLUSION

In patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy, the combined evaluation of pathologic stage and after-radiochemotherapy (18)F-FDG PET at restaging identified a subgroup of patients characterized by good response to radiochemotherapy and a more favorable prognosis. In these patients, a conservative surgical approach might be considered.

Retrospective Study of Capecitabine and Celecoxib In Metastatic Colorectal Cancer

OBJECTIVE

COX-2 activation may mediate capecitabine induced toxicities, eg, hand-foot syndrome (HFS) and colorectal cancer progression, both of which may be improved by concurrent celecoxib.

PATIENTS AND METHODS

From October 2000 to December 2003, 66 patients with metastatic colorectal cancer received concurrent capecitabine at 1000 mg/m/d b.i.d. and celecoxib at 200 mg b.i.d. (XCEL). Twenty-four patients were chemo-naive, 42 patients were second-line; while 34 had XCEL with radiation.

RESULTS

The median duration of XCEL was 7.2 months (range, 1.5-38 months). Ninety percent of Grade 2/3 HFS (17%) occurred after 6 months and incidence of grade 3/4 diarrheas was 8%. The overall response rate was 38% (95% confidence interval [CI], 26-51%), with 11 patients (17%) achieving complete responses and 2 patients (3%) with near complete responses. Six patients (9%) become resectable after sustaining treatment response. The median progression-free survival (PFS) and overall survival (OS) was 8.3 months (95% CI, 7.0-11.0 months) and 22 months (95% CI, 17.8-31.5 months), respectively. Improved median PFS of 14.5 months (P = 0.0001) and OS of 31.5 months (P = 0.005) were noted in patients with normal lactate dehydrogenase (LDH) levels (n = 37) than patients with high levels of LDH (n = 29).

CONCLUSIONS

XCEL integrating radiation may improve response rate and survival and reduce toxicities, notably HFS for patients with metastatic colorectal cancer, leading to a randomized phase III study.