Pre-operative chemoradiation for non-metastatic locally advanced rectal cancer

Landscape of mortality during and within thirty days after non-palliative radiotherapy across eleven major cancer types

BACKGROUND AND PURPOSE

Peri-RT mortality (death during or within 30 days of non-palliative radiotherapy) has been historically overlooked, and rates and risk factors are unclear.

MATERIALS AND METHODS

Patients with non-metastatic cancer, treated with non-palliative external beam radiation (RT) 2004-2016, were identified in the National Cancer Database for 11 cancer types: breast, prostate, non-prostate genitourinary, bone/soft tissue, gynecological, head/neck, lymphoma, gastrointestinal (GI), small cell lung, non-small cell lung, and central nervous system (CNS). Multivariable logistic regression was used to identify predictors of peri-RT mortality controlled for 17 covariates, including patient, tumor, and treatment factors.

RESULTS

Approximately 1.53 million patients were identified. Peri-RT mortality was 2.46% overall, spanning two orders of magnitude from 0.14% for breast to 8.52% for CNS. Peri-RT mortality steadily improved from 3.13% in 2004 to 1.78% in 2016 (P < .0001). Major predictors of peri-RT mortality included age, baseline comorbidity, male sex, and stage (P < .0001). Conversely, higher patient volume at the treating facility and use of more conformal RT planning techniques were moderately protective (P < .0001). Racial disparities varied based on disease site, as Black patients had increased peri-RT mortality for breast, lymphoma, and GI cancers, but not for other cancer types. Lack of private insurance was associated with substantially increased peri-RT mortality regardless of cancer type.

CONCLUSION

Peri-RT mortality varied considerably according to multiple factors. Sociodemographic differences highlight areas of health disparities and opportunities for quality improvement. Early recognition of patients at increased risk may facilitate implementation of closer monitoring or other preventive measures.

The Survival Effect of Radiotherapy on Stage II/III Rectal Cancer in Different Age Groups: Formulating Radiotherapy Decision-Making Based on Age

Introduction

Total mesorectal excision (TME), chemotherapy (CT), and radiotherapy (RT) are usually integrated into the comprehensive treatment of stage II/III rectal cancer (RC). Neoadjuvant radiotherapy (nRT) has become the standard treatment for stage II/III RC patients to help reduce the size of a tumor or kill cancer cells that have spread. Adjuvant RT is delivered after the resection to destroy remaining cancer cells and used mainly in stage II/III RC patients who have not received preoperative radiotherapy, such as those who suffered from a bowel obstruction before surgery. It is controversial whether radiotherapy can improve the survival of stage II/III RC patients. An increasing number of studies have reported that rectal cancer exhibited mismatched biology, epidemiology, and therapeutic response to current treatment strategy in different age groups. It is necessary to investigate whether radiotherapy exhibits disparate effects in different age groups of patients with stage II/III RC.

Methods

Data from the Surveillance, Epidemiology, and End Results (SEER) Program was extracted to identify stage II/III RC diagnosed in the periods of 2004-2016. The statistical methods included Pearson's chi-square test, log-rank test, Cox regression model, and propensity score matching.

Results

Neoadjuvant radiotherapy (nRT) cannot improve the prognosis, and postoperative RT may even reduce the survival time for early onset stage II/III RC. Postoperative RT was not able to improve the overall survival (OS), while nRT may provide limited survival improvement for middle-aged stage II/III RC patients. In addition, radiotherapy can significantly improve the prognosis for elderly stage II/III RC.

Conclusions

This study indicated the inconsistent survival effect of radiotherapy on stage II/III rectal cancer patients in different age groups. Hence, we formulated a novel flow chart of radiotherapy decision-making based on age in stage II/III RC patients.

Multi-parametric magnetic resonance imaging assessment of whole tumour heterogeneity for chemoradiotherapy response prediction in rectal cancer

Background and purpose

Prediction of chemoradiotherapy response (CRT) in locally advanced rectal cancer would enable stratification of management. The purpose was to prospectively evaluate multi-parametric magnetic resonance imaging (MRI) assessment of tumour heterogeneity combining diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) MRI for the prediction of CRT response in locally advanced rectal cancer.

Materials and methods

Patients with Stage II or III rectal adenocarcinoma undergoing neoadjuvant CRT and surgery underwent MRI (DWI and DCE) before, during (week 3), and after CRT (1 week before surgery). Patients with histopathology tumour regression grade (TRG) 0-1 were classified as responders, and TRG 2-3 were classified as non-responders. A whole tumour voxel-wise technique was used to produce apparent diffusion coefficient (ADC) and K^trans (Tofts model) histograms derived from DWI and DCE-MRI, respectively. Logistic regression was used to predict response status for ADC and K^trans quantiles.

Results

Thirty-three patients were included in this analysis; 16 responders, and 17 non-responders. On heterogeneity analysis, odds of being a responder were significantly higher after CRT (before surgery) for higher ADC 75th (p = 0.049) and ADC 90th (p = 0.034) percentile values. The K^trans quantiles were lower in non-responders than responders before and during CRT, and higher after CRT although no significant association with response status was observed (p ≥ 0.10).

Conclusions

DWI-MRI after CRT (before surgery) incorporating a histogram analysis of whole tumour heterogeneity was predictive of CRT response in patients with locally advanced rectal cancer. DCE-MRI did not add value in response prediction.

Clinical trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR) number ACTRN12616001690448.

Sexual organ-sparing with hydrogel spacer injections for rectal cancer radiotherapy: a feasibility pilot study

OBJECTIVES

The aim of this pilot study was to investigate in two rectal cancer patients undergoing neoadjuvant chemo-radiotherapy (nCRT) the implant feasibility and dosimetric benefit in sexual organ-sparing of an injectable, absorbable, radiopaque hydrogel spacer.

METHODS

Two rectal cancer patients (one male and one female) underwent hydrogel implant between rectum and vagina/prostate before nCRT and curative surgery. A CT scan was performed before and after injection and a comparative dosimetric study was performed testing a standard (45/50 Gy) and a dose escalated (46/55.2 Gy) schedule.

RESULTS

In both patients, the spacer implant in the recto-prostatic or recto-vaginal space was feasible and well tolerated. For the male, the dosimetric benefit with spacer was minimal for sexual organs. For the female however, doses delivered to the vagina were significantly reduced with spacer with a mean reduction of more than 5 Gy for both regimens.

CONCLUSIONS

For organ preservation protocols and selected sexually active female patients, use of hydrogel spacers can be considered to spare sexual organs from the high radiotherapy dose levels.

ADVANCES IN KNOWLEDGE

For females with advanced rectal tumor, a spacer implant between the rectum and the vagina before nCRT is feasible and reduces doses delivered to the vagina.

Oncological Outcomes of Robotic-Assisted Surgery With High Dissection and Selective Ligation Technique for Sigmoid Colon and Rectal Cancer

Background: Curative resection of sigmoid colon and rectal cancer includes "high tie" of the inferior mesenteric artery (IMA). However, IMA ligation compromises blood flow to the anastomosis, which may increase the complication rate. We present preliminary experiences of operative and oncologic outcomes of patients with rectal or sigmoid colon cancer who underwent robotic surgery employing the high dissection and selective ligation technique. Methods: Over May 2013 to April 2017, 113 stage I-III rectal or sigmoid colon cancer patients underwent robotic surgery with the single-docking technique at one institution. We performed D3 lymph node dissection and low-tie ligation of the IMA (i.e., high dissection and selective ligation technique). Clinicopathological features, perioperative parameters, and postoperative outcomes were retrospectively analyzed. Overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method. Results: Sphincter preservation rate was 96.3% in rectal cancer patients. Median number of harvested lymph nodes was 12. Apical nodes were pathologically harvested in 84 (82.4%) patients. R0 resection was performed in 108 (95.6%) patients. Overall complication rate was 17.7%; but most complications were mild and the patients recovered uneventfully. Estimated 5-year OS was 86.1% and 3-year DFS was 79.6% after median follow-up periods of 49.1 months (range, 5.3-85.3). Conclusions: High dissection of the IMA and selective ligation of the major feeding vessel to the sigmoid colon or rectum can be safely performed using da Vinci Surgical System,yielding favorable clinical, and oncologic outcomes in rectal or sigmoid colon cancer treatment.

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.

Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: preliminary results of a randomized controlled trial

Purpose

Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients.

Materials and Methods

In this clinical trial we recruited patients with rectal adenocarcinoma located from 5 cm to 15 cm above the anal verge. Patients in group I (short-course) received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/m² from day 1–5 twice daily and oxaliplatin 50 mg/m² on day 1 once daily). Patients in group II (long-course) received a total dose of 50–50.4 Gy/25–28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/m² twice daily. Both groups underwent consolidation chemotherapy followed by delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade.

Results

In this preliminary report on complications and pathological response, 66 patients were randomized into two study groups. Mean duration of radiotherapy in groups I and II was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the short-course and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group except one grade 4 hematologic toxicity that was seen in group II. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333).

Conclusion

For patients with rectal cancer located at least 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy.

Optimize the dose of oxaliplatin for locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by radical surgery and adjuvant chemotherapy

Background

Addition of oxaliplatin to capecitabine remains controversial for locally advanced rectal cancer (LARC). And cumulative oxaliplatin dose (COD) varied among clinical trials showing different therapeutic effects of this regimen. The objective of this study was to explore how COD affected tumor metastasis and patient survival.

Methods

Totally 388 patients diagnosed with stage cII-III rectal cancer and treated with neoadjuvant chemoradiotherapy followed by radical surgery plus adjuvant chemotherapy were consecutively enrolled into this study and retrospectively reviewed. After grouping by total chemotherapy cycle (TCC), influences of COD on adverse effects and patients’ survivals were analyzed in each group. Univariate and multivariate survival analyses were performed through Kaplan-Meier approach and COX proportional hazards model, respectively. Age, gender, anemia, differentiation, carcinoembryonic antigen, carbohydrate antigen 19–9, pretreatment clinical stage and postsurgical pathologic stage were used as covariates.

Results

COD < 460 mg/m² emerged as an independent predictor of poorer overall, metastasis-free and disease-free survivals, in patients treated with TCC ≤ 7. The hazard ratios were 1.972, 1.763 and 1.637 (P values were 0.021, 0.028 and 0.041), respectively. But it was note-worthy that COD ≥460 mg/m² increased incidence of acute toxicities from 38.4 to 70.8% (P < 0.001). And in patients treated with TCC ≥ 8, COD failed to be a prognosticator.

Conclusions

For LARC patients treated with insufficient TCC (≤ 7), oxaliplatin of ≥460 mg/m² might be needed to improve survival, though it might resulted in more acute toxicities.

MRI response rate after short-course radiotherapy on rectal cancer in the elderly comorbid patient: results from a retrospective cohort study

Background

The aim of the present study was to evaluate MRI response rate and clinical outcome of short-course radiotherapy (SCRT) on rectal cancer as an alternative to chemoradiotherapy in patients where downstaging is indicated.

Methods

A retrospective analysis was performed of a patient cohort with rectal carcinoma (cT1-4cN0-2 cM0–1) from a large teaching hospital receiving restaging MRI, deferred surgery or no surgery after SCRT between 2011 and 2017. Patients who received chemotherapy during the interval between SCRT and restaging MRI were excluded.

The primary outcome measure was the magnetic resonance tumor regression grade (mrTRG) at restaging MRI after SCRT followed by a long interval. Secondary, pathological tumor stage, complete resection rate and 1-year overall survival were assessed.

Results

A total of 47 patients (M:F = 27:20, median age 80 (range 53–88) years), were included. In 33 patients MRI was performed for response assessment 10 weeks after SCRT. A moderate or good response (mrTRG≤3) was observed in 24 of 33 patients (73%). While most patients (85%; n = 28) showed cT3 or cT4 stage on baseline MRI, a ypT3 or ypT4 stage was found in only 20 patients (61%) after SCRT (p <  0.01). A complete radiologic response (mrTRG 1) was seen in 4 patients (12%). Clinical N+ stage was diagnosed in n = 23 (70%) before SCRT compared to n = 8 (30%) post-treatment (p = 0.03).

After SCRT, 39 patients underwent deferred surgery (after a median of 14 weeks after start of SCRT) and a resection with complete margins was achieved in 35 (90%) patients. One-year overall survival after surgery was 82%. Complete pathological response was found in 2 patients (5%).

Conclusions

The use of SCRT followed by a long interval to restaging showed a moderate to good response in 73% and therefore can be considered as an alternative to chemoradiotherapy in elderly comorbid patients.

Neoadjuvant radiotherapy improves overall survival for T3/4N+M0 rectal cancer patients: a population-based study of 20300 patients

Background

Neoadjuvant radiotherapy (RT) has been shown to improve local control; however, whether it can improve overall survival (OS) in locally advanced rectal cancer (LARC) patients remains controversial. We therefore aimed to examine the benefits of surgery alone, neoadjuvant radiotherapy (RT), adjuvant RT, and surgery plus chemotherapy in stage II (T3/4N0M0) and III (any T and N + M0) on the OS of rectal cancer patients.

Methods

Date from the Surveillance, Epidemiology, and End Results (SEER) database diagnosed between 2004 and 2016 were used. Kaplan-Meier analyses were used to compare patient prognoses across different treatment modalities. Cox hazard regression analysis were used to identify independent predictors of OS.

Results

For stage T3/4N0M0 patients, neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy resulted in similar OS (all p > 0.05; mean survival, 115.89 months (M), 111.97 M, and 117.22 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival, 88.96 M). For stage T1/2N + M0 patients, neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy resulted in similar OS (all p > 0.05; mean survival, 121.50 M, 124.25 M, and 121.20 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival 83.81 M). For stage T3/4N + M0 patients, neoadjuvant RT (HR = 0.436; 95% CI, 0.396~0.478; p < 0.001) resulted in significantly longer OS than adjuvant RT and surgery plus chemotherapy (mean survival, 104.47 M, 93.94 M, and 93.62 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival 54.87 M). Older age (> 60 years), black race, unmarried status, high tumour grade, and tumour size > 5 cm were all associated with a poor prognosis (all p < 0.05).

Conclusions

Neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy results in better OS than surgery alone in LARC patients. Neoadjuvant RT has the potential to be highly recommended over adjuvant RT and surgery plus chemotherapy for T3/4N + M0 patients; however, it showed no OS advantage over adjuvant RT or surgery plus chemotherapy for T3/4N0M0 and T1/2N + M0 patients.

The clinical significance of simple endoscopic scoring of patients with rectal cancer after concurrent chemoradiotherapy

BACKGROUND

Neoadjuvant concurrent chemoradiotherapy (CCRT) is an effective treatment option for patients with rectal cancer. In this study, we investigated the clinical efficacy of simple endoscopic scoring of patients with rectal cancer after CCRT.

METHODS

Between July 2008 and October 2015, medical records including endoscopic imaging from 41 patients with rectal cancer who received CCRT were retrospectively reviewed. Two expert gastroenterologists reviewed the endoscopic images and assigned scores from 0-3 according to post-CCRT findings. The scoring criteria were as follows: 0= scar without marginal elevation; 1= clean-based ulcer without marginal elevation; 2= clean-based ulcer with marginal elevation; 3= non-clean-based ulcer. We evaluated image scores to predict long-term outcomes using Kaplan-Meier curves and Cox regression models.

RESULTS

The median follow-up duration was 55 months (interquartile range: 35-76 months). Patients with a low score (≤2) had a 17.2% recurrence rate, whereas patients with a high score [3] had a 50.0% recurrence rate. Patients with a low score had longer disease-free survival (DFS) than those with a high score in log-rank test (P=0.026). In multivariate Cox regression analysis, a high score was a significant predictor of poor DFS in patients with rectal cancer after CCRT treatment (hazard ratio =4.89, 95% confidence interval: 1.11-21.50, P=0.036).

CONCLUSIONS

This simple endoscopic scoring approach is helpful for predicting prognosis of patients with rectal cancer after treatment with CCRT.

Preoperative short-course radiotherapy (5 × 5 Gy) with delayed surgery versus preoperative long-course radiotherapy for locally resectable rectal cancer: a meta-analysis

PURPOSE

Preoperative short-course radiotherapy (PSRT) and preoperative long-course radiotherapy (PLRT) are standard treatment regimens for locally advanced rectal cancer. However, whether the efficacy and safety of PSRT with delayed surgery (more than 4 weeks) are superior to those of PLRT remains unresolved and was explored in this meta-analysis.

METHODS

Studies published in PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov databases were systematically searched. RevMan 5.3 was used to calculate pooled hazard ratios (HR) and relative risk (RR).

RESULTS

Seven studies including 4973 patients were identified in the meta-analysis. Pooled statistics showed that there was no statistically significant difference in overall survival (HR = 1.30, 95% CI 0.58-2.89, P = 0.52) or disease-free survival (HR = 1.10, 95% CI 0.73-1.66, P = 0.64) between the preoperative short-course and long-course radiotherapy groups. Moreover, pathological complete remission, early postoperative complications, treatment-related grade 3/4 toxicity, local recurrence, and distant metastasis were similar between the two groups. Interestingly, a subgroup analysis revealed that preoperative short-course radiotherapy without adjuvant chemotherapy not only resulted in lower treatment-related grade 3/4 toxicity than the long-course radiotherapy group (RR = 0.19, 95% CI 0.08-0.48, P < 0.01) but also resulted in significantly lower overall survival and pathological complete remission (P = 0.02, P < 0.01, respectively). Disappointingly, pooled statistics observed few advantages over long-course radiotherapy in short-course radiotherapy with the adjuvant chemotherapy subgroup.

CONCLUSIONS

PSRT with delayed surgery was as effective as PLRT for the management of locally resectable rectal cancer. However, not adding additional chemotherapy to PSRT not only significantly decreased grade 3/4 toxicity but also decreased pathological complete remission and overall survival.

TRIAL REGISTRATION

The protocol for this meta-analysis was prospectively registered with PROSPERO (CRD42019133641).

Elastic scattering spectroscopy for monitoring skin cancer transformation and therapy in the near infrared window

There is a pressing need for monitoring cancerous tissue response to laser therapy. In this work, we evaluate the viability of elastic scattering spectroscopy (ESS) to monitor malignant transformations and effects of laser therapy of induced skin cancer in a hamster model. Skin tumors were induced in 35 mice, half of which were irradiated with 980 nm laser diode. Physiological and morphological transformations in the tumor were monitored over a period of 36 weeks using elastic scattering spectroscopy, in the near infrared window. Analytical model for light scattering was used to derive scattering optical properties for both transformed tissue and laser-treated cancer. The tissue scattering over the wavelength range (700-950 nm) decreased remarkably as the carcinogen-induced tissue transformed towards higher stages. Conversely, reduced scattering coefficient noticeably increased with increasing the number of laser irradiation sessions for the treated tumors. The relative changes in elastic scattering signal for transformed tissue were significantly different (p < .05). Elastic scattering signal intensity for laser-treated tissue was also significantly different (p < .05). Reduced scattering coefficient of treated tissue exhibited nearly 80% recovery of its normal skin value at the end of the experiment, and the treatment outcome could be improved by adjusting the number of sessions, which we can predict through spectroscopic optical feedback. This study demonstrates that ESS can quantitatively provide functional information that closely corresponds to the degree of pathologic transformation. ESS may well be a viable technique to optimize systemic melanoma and non-melanoma skin cancer treatment based on noninvasive tumor response.

Neoadjuvant Modified FOLFOX6 With or Without Radiation Versus Fluorouracil Plus Radiation for Locally Advanced Rectal Cancer: Final Results of the Chinese FOWARC Trial

PURPOSE

In the multicenter, open-label, phase III FOWARC trial, modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus radiotherapy resulted in a higher pathologic complete response rate than fluorouracil plus radiotherapy in Chinese patients with locally advanced rectal cancer. Here, we report the final results.

METHODS

Adults ages 18 to 75 years with stage II/III rectal cancer were randomly assigned (1:1:1) to five cycles of infusional fluorouracil (leucovorin 400 mg/m², fluorouracil 400 mg/m², and fluorouracil 2.4 g/m² over 48 hours) plus radiotherapy (46.0 to 50.4 Gy delivered in 23 to 25 fractions during cycles 2 to 4) followed by surgery and seven cycles of infusional fluorouracil, the same treatment plus intravenous oxaliplatin 85 mg/m² on day 1 of each cycle (mFOLFOX6), or four to six cycles of mFOLFOX6 followed by surgery and six to eight cycles of mFOLFOX6. The primary end point was 3-year disease-free survival (DFS).

RESULTS

In total, 495 patients were randomly assigned to treatment. After a median follow-up of 45.2 months, DFS events were reported in 46, 39, and 46 patients in the fluorouracil plus radiotherapy, mFOLFOX6 plus radiotherapy, and mFOLFOX6 arms. In each arm, the probability of 3-year DFS was 72.9%, 77.2%, and 73.5% (P = .709 by the log-rank test), the 3-year probability of local recurrence after R0/1 resection was 8.0%, 7.0%, and 8.3% (P = .873 by the log-rank test), and the 3-year overall survival rate was 91.3%, 89.1%, and 90.7% (P = .971 by log-rank test), respectively.

CONCLUSION

mFOLFOX6, with or without radiation, did not significantly improve 3-year DFS versus fluorouracil with radiation in patients with locally advanced rectal cancer. No significant difference in outcomes was found between mFOLFOX6 without radiotherapy and fluorouracil with radiotherapy, which requires additional investigation of the role of radiotherapy in these regimens.

Genome landscapes of rectal cancer before and after preoperative chemoradiotherapy

Resistance to preoperative chemoradiotherapy (CRT) is a major obstacle to cancer treatment in patients with locally advanced rectal cancer. This study was to explore genome alterations in rectal cancer under CRT stress.

Methods: Whole-exome sequencing (WES) was performed on 28 paired tumors collected before and after CRT from the same patients who did not respond to CRT treatment. Somatic point mutations and copy number variations were detected by VarScan2 and Exome CNVs respectively using paired tumor and blood samples. Somatic alterations associated with CRT resistance were inferred considering differences in significantly mutated genes, mutation counts and cancer cell fraction between matched pre- and post-CRT tumors. We employed SignatureAnalyzer to infer mutation signatures and PyClone to decipher clonal evolution and examine intratumoral heterogeneity in tumors before and after CRT. The associations between intratumoral heterogeneity and patients' survival were analyzed using the log-rank test and the Cox regression model.

Results: (i) Recurrent mutations in CTDSP2, APC, KRAS, TP53 and NFKBIZ confer selective advantages on cancer cells and made them resistant to CRT treatment. (ii) CRT alters the genomic characteristics of tumors at both the somatic mutation and the copy number variation levels. (iii) CRT-resistant tumors exhibit either a branched or a linear evolution pattern. (iv) Different recurrent mutation signatures in pre-CRT and post-CRT patients implicate mutational processes underlying the evolution of CRT-resistant tumors. (v) High intratumoral heterogeneity in pre- or post-CRT is associated with poor patients' survival.

Conclusion: Our study reveals genome landscapes in rectal cancer before and after CRT and tumors evolution under CRT stress. The treatment-associated characteristics are useful for further investigations of CRT resistance in rectal cancer.

Pelvic insufficiency fractures, dose volume parameters and plan optimization after radiotherapy for rectal cancer

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High rates of PIF are detected 3 years after VMAT based CRT for rectal cancer.

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Patients with PIFs received non-significantly higher V30 Gy to sacroiliac joints.

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3 arc VMAT techniques can be optimized for bone.

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Proton beam therapy has the potential for further optimization for bone.

Pelvic insufficiency fractures (PIF) is a known but under-acknowledged late effect of pelvic radiotherapy. In rectal cancer, studies describing incidence of PIF and relation to dose volume relationships are lacking. The aim of this study was (i) to analyse dose volume histograms (DVH) from pelvic bones in patients with and without PIF, and (ii) to determine bone sparing capacity of 2 and 3 arc volumetric arc therapy (VMAT), intensity modulated radiotherapy (IMRT) and proton beam therapy (PBT), in rectal cancer patients treated with chemoradiotherapy (CRT).

Material and methods

Patients treated with CRT for primary rectal cancer underwent a 3-year pelvic MRI for identification of PIFs. Bone structures were retrospectively delineated, and DVHs were re-calculated. Comparative planning was done with 2 (original) and 3 arc VMAT, fixed field IMRT and PBT plans.

Results

27 patients (18 men, mean age 64 years) were included and PIFs were identified in 9 (33%), most (n = 6) had multiple fracture sites. In general, patients with PIFs received higher doses to pelvic bones, and V30 Gy to the sacroiliac joint was non-significantly higher in patients with PIF 68.5% (60.1–69.3 IQR) vs. 56% (54.1–66.6 IQR), p = 0.064. Comparative planning showed that especially 3 arc VMAT and proton beam therapy could be optimized for bone.

Conclusions

Patients, treated with VMAT based CRT for rectal cancer, have high rates of PIFs after 3 years. Patients with PIFs tended to have received higher doses to sacroiliac joints. Comparative planning demonstrated most pronounced bone sparing capacity of 3 arc VMAT and with PBT having the potential to further lower doses. These results should be validated in larger and preferably prospective cohorts.

Treatment selection bias for chemotherapy persists in colorectal cancer patient cohort studies even in comprehensive propensity score analyses

Introduction

Propensity score methods are increasingly used to address confounding related to treatment selection in observational studies. Studies estimating the effect of chemotherapy in colon cancer (CC) patients, however, often lacked information on pertinent comorbidities and functional status (FS). We assessed to what extent comorbidities and FS impact treatment decisions in colorectal cancer patients and explain the benefit of chemotherapy in stage III CC patients.

Methods

Stage II-III colorectal cancer patients diagnosed in 2003-2014 and recruited into a population-based study were included (N=1102). Associations of comorbidity and FS with treatment patterns were examined with multivariable logistic regression. The contribution of lower comorbidity and higher FS to the benefit of chemotherapy was estimated with propensity score weighted Cox models in 430 stage III CC patients who were followed over a median time of 4.7 years.

Results

In stage II (high-risk) and III CC patients, Charlson comorbidity scores 1, 2 and 3+ were associated with 57%, 66% and 70% lower odds of chemotherapy use, respectively. In combination with older age and poor FS, comorbidity was associated with 97% and 83% decreased odds of adjuvant chemotherapy use in CC and rectal cancer patients, respectively. In stage III CC patients, lower comorbidity and higher FS explained 38% and 24% of the overall and disease-specific survival benefits of chemotherapy, respectively. Selection bias was observed even in the comprehensive models, as chemotherapy was still associated with substantially higher non-disease-specific survival (hazard ratio (HR): 0.66; 95% confidence interval (CI): 0.46-0.92), especially in patients <75 years (HR: 0.33; 95% CI: 0.17-0.63).

Conclusion

Lower comorbidity and higher FS of recipients of chemotherapy explain approximately 40% of the benefits of chemotherapy in stage III CC patients. Regardless of how comprehensive propensity score analyses might be in observational studies, treatment selection bias might persist and affect estimates of treatment effects.

Diabetes Mellitus and Colon Carcinogenesis: Expectation for Inhibition of Colon Carcinogenesis by Oral Hypoglycemic Drugs

The global deaths due to colorectal cancer and diabetes mellitus have increased by 57% and 90%, respectively. The relationship between various cancers and diabetes mellitus has been shown in multiple epidemiological studies. Hence, better management of diabetes mellitus is expected to reduce the risk of various cancers. This review focuses on colorectal cancer and aims to summarize recent findings on the antitumor effects of various oral hypoglycemic drugs on colorectal cancer and their estimated mechanisms. Of the seven classes of oral hypoglycemic agents, only metformin was found to have suppressive effects on colorectal cancer in both clinical and basic research. Clinical and basic researches on suppressing effects of glinides, dipeptidyl peptidase-4 inhibitors, thiazolidinedione, α-glucosidase inhibitors, and sodium glucose cotransporter-2 inhibitors against colon carcinogenesis have been insufficient and have not arrived at any conclusion. Therefore, further research regarding these agents is warranted. In addition, the suppressive effects of these agents in healthy subjects without diabetes should also be investigated.

Locally advanced rectal adenocarcinoma: Are preoperative short and long course radiotherapy truly equivalent?

In the neoadjuvant treatment of locally advanced rectal adenocarcinoma, long- and short-course radiotherapy are considered to be of equivalent efficacy based upon several randomized trials. The present study assessed the effect of radiotherapy dose on overall survival. Using the National Cancer Database (2006-2013) 458 individuals with clinical stage II/III rectal adenocarcinoma treated were identified, with either short- (25 Gy) or long- (45 or 50.4 Gy) course neoadjuvant radiotherapy followed by surgery, without neoadjuvant or adjuvant chemotherapy. Multivariate COX regression was employed to evaluate differences in overall survival according to radiotherapy regimen. An association with improved overall survival in individuals treated with long- compared with short-course radiotherapy was demonstrated (HR=0.50, 0.34-0.73). The 30- and 90-day post-surgery mortality rates were higher in the short-course group when compared with the long-course group (12.2 vs. 2.4%; and 18.5 vs. 5.4%, respectively). Following the exclusion of patients that succumbed within 90-days post-surgery, overall survival advantage in the long-course group compared with the short-course group was maintained [hazard ratio (HR)=0.62, 0.39-0.99], with a median overall survival of 25.3 months (IQR 16.9-41.6) for the short-course group compared with 43.5 months (IQR 25.6-67.9) for the long-course group. To the best of our knowledge, the present results suggest for the first time that long-course radiotherapy is associated with an improved overall survival compared with short-course radiotherapy in locally advanced rectal adenocarcinoma in the absence of chemotherapy usage. This possible advantage is clinically relevant mainly in patients who cannot tolerate systemic chemotherapy.

Magnetic-Resonance-Imaging Texture Analysis Predicts Early Progression in Rectal Cancer Patients Undergoing Neoadjuvant Chemoradiation

Background

We hypothesized that texture analysis (TA) from the preoperative MRI can predict early disease progression (ePD), defined as the percentage of patients who relapsed or showed distant metastasis within three months from the radical surgery, in patients with locally advanced rectal cancer (LARC, stage II and III, AJCC) undergoing neoadjuvant chemoradiotherapy (C-RT).

Methods

This retrospective monoinstitutional cohort study included 49 consecutive patients in total with a newly diagnosed rectal cancer. All the patients underwent baseline abdominal MRI and CT scan of the chest and abdomen to exclude distant metastasis before C-RT. Texture parameters were extracted from MRI performed before C-RT (T1, DWI, and ADC sequences) using LifeX Software, a dedicated software for extracting texture parameters from radiological imaging. We divided the cohort in a training set of 34 patients and a validation set of 15 patients, and we tested the data sets for homogeneity, considering the clinical variables. Then we performed univariate and multivariate analysis, and a ROC curve was also generated.

Results

Thirteen patients (26.5%) showed an ePD, three of whom with lung metastases and ten with liver relapse. The model was validated based on the prediction accuracy calculated in a previously unseen set of 15 patients. The prediction accuracy of the generated model was 82% (AUC = 0.853) in the training and 80% (AUC = 0.833) in the validation cohort. The only significant features at multivariate analysis was DWI GLCM Correlation (OR: 0.239, p < 0.001).

Conclusion

Our results suggest that TA could be useful to identify patients that may develop early progression.

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.

Peroxiredoxins in Colorectal Cancer: Predictive Biomarkers of Radiation Response and Therapeutic Targets to Increase Radiation Sensitivity?

Colorectal cancer (CRC) is the third most common cancer in the Western world, with one-third of cases located in the rectum. Preoperative radiotherapy is the standard of care for many patients with rectal cancer but has a highly variable response rate. The ability to predict response would be of great clinical utility. The response of cells to ionizing radiation is known to involve immediate damage to biomolecules and more sustained disruption of redox homeostasis leading to cell death. The peroxiredoxins are an important group of thiol-dependent antioxidants involved in protecting cells from oxidative stress and regulating signaling pathways involved in cellular responses to oxidative stress. All six human peroxiredoxins have shown increased expression in CRC and may be associated with clinicopathological features and tumor response to ionizing radiation. Peroxiredoxins can act as markers of oxidative stress in various biological systems but they have not been investigated in this capacity in CRC. As such, there is currently insufficient evidence to support the role of peroxiredoxins as clinical biomarkers, but it is an area worthy of investigation. Future research should focus on the in vivo response of rectal cancer to radiotherapy and the redox status of peroxiredoxins in rectal cancer cells, in order to predict response to radiotherapy. The peroxiredoxin system is also a potential therapeutic target for CRC.

Abdominoperineal Resection for Rectal Cancer in the Twenty-First Century: Indications, Techniques, and Outcomes

BACKGROUND

Management of low rectal cancer continues to be a challenge, and decision making regarding the need for an abdominoperineal resection (APR) in patients with low-lying tumors is complicated. Furthermore, choices need to be made regarding need for modification of the surgical approach based on tumor anatomy and patient goals.

DISCUSSION

In this article, we address patient selection, preoperative planning, and intraoperative technique required to perform the three types of abdominoperineal resections for rectal cancer: extrasphincteric, extralevator, and intersphincteric. Attention is paid not only to traditional oncologic outcomes such as recurrence and survival but also to patient-reported outcomes and quality of life.

Comparison of guidelines for the management of rectal cancer

A comparison between NCCN, ESMO and JSCCR Guidelines is presented, concerning the treatment of rectal cancer, with an analysis and discussion of their discrepancies. Differences indicate areas for research.

Treatment of primary rectal adenocarcinoma after prior pelvic radiation: The role of hyperfractionated accelerated reirradiation

Purpose

Previous studies have reported that hyperfractionated accelerated reirradiation can be used as part of multimodality treatment of locally recurrent rectal cancer with acceptable toxicity and promising outcomes. The purpose of this study was to evaluate the outcomes and toxicity of hyperfractionated accelerated reirradiation for patients with primary rectal adenocarcinoma and a history of prior pelvic radiation for other primary malignancies.

Methods and materials

We identified 10 patients with a prior history of pelvic radiation for other primary malignancies who were treated with hyperfractionated accelerated reirradiation for primary rectal adenocarcinoma. Radiation therapy was administered with 1.5 Gy twice daily fractions to a total dose of 39 Gy to 45Gy.

Results

The median follow-up time was 3.2 years (range, 0.6-9.0 years). Seven of 10 patients received surgery after reirradiation. The 3-year freedom-from-local-progression rate was 62% for all patients and 80% for patients who underwent surgery. The 3-year overall survival rate was 100%, with 3 deaths occurring at 4.7, 6.5, and 9.0 years after reirradiation. One patient had an acute Grade 3 toxicity of diarrhea, and 1 patient experienced a late Grade 3 toxicity of sacral insufficiency fracture.

Conclusions

Hyperfractionated accelerated reirradiation was well tolerated with promising rates of freedom from local progression and overall survival in patients with primary rectal cancer with a history of prior pelvic radiation therapy. This approach, along with concurrent chemotherapy and surgery, appears to be a viable treatment strategy for this patient population.

Impact of Adjuvant Therapy Type on Survival in Stage II/III Rectal Cancer Without Preoperative Chemoradiation: A Korean Multicenter Retrospective Study

Purpose

This study compared the oncologic impact of postoperative chemotherapy and chemoradiotherapy on patients with rectal cancer without preoperative chemoradiation.

Methods

This retrospective study analyzed 713 patients with a mean follow-up of 58 months who had undergone radical resection for stage II/III rectal cancer without preoperative treatment in nine hospitals from January 2004 to December 2009. The study population was categorized a chemotherapy group (CG, n = 460) and a chemoradiotherapy group (CRG, n = 253). Five-year overall survival (OS) and disease-free survival (DFS) were analyzed, and independent factors predicting survival were identified.

Results

The patients in the CRG were significantly younger (P < 0.001) and had greater incidences of low rectal cancer (P < 0.001) and stage III disease (P < 0.001). Five-year OS (P = 0.024) and DFS (P = 0.012) were significantly higher in the CG for stage II disease; however, they were not significantly different for stage III disease. In the multivariate analysis, independent predictive factors were male sex, low rectal cancer and stage III disease for OS and male sex, abdominoperineal resection, stage III disease and tumor-positive circumferential margin for DFS. However, adjuvant therapy type did not independently affect OS (hazard ratio [HR], 1.243; 95% confidence interval [CI], 0.794–1.945; P = 0.341) and DFS (HR, 1.091; 95% CI, 0.810–1.470; P = 0.566).

Conclusion

Adjuvant therapy type did not affect survival of stage II/III rectal cancer patients without neoadjuvant chemoradiotherapy. These results suggest that adjuvant therapy can be chosen based on the patient’s condition and the policies of the surgeons and hospital facilities.

Dose-finding study of oxaliplatin associated to capecitabine-based preoperative chemoradiotherapy in locally advanced rectal cancer

Introduction

Proper administration timing, dose-intensity, efficacy/toxicity ratio of oxaliplatin added to fluoropyrimidin should be improved to safely perform two-drugs intensive preoperative chemoradiotherapy in locally advanced rectal cancer (LARC). This dose-finding study investigated recommended oxaliplatin dose, safety of oxaliplatin/capecitabine regimen and preliminary activity.

Methods

Schedule: oxaliplatin dose-levels, 35-40 mg/m²/week; capecitabine 825 mg/m²/ twice daily, radiotherapy on rectum/nodes, 50/45 Gy, 45 and 9 boost/45 Gy, in first 5 and subsequent patients, 5 days/week, respectively; for 5 weeks. Pathologic complete response (pCR) 10% was projected in order to positively affect clinical outcome.

Results

Seventeen fit <75 years patients enrolled: median age 60; young-elderly 4 (23%); T3/T4, 15/2, N0/N1/N2, 7/9/1. At first dose-level, no dose-limiting toxicity (DLT). At second, 2 DLT, G3 mucositis, G3 thrombocytopenia, in 2/6 patients (33%). Oxaliplatin recommended dose, 40 mg/m²/week. Cumulative G3-4 toxicities: mucositis 6%, thrombocytopenia 6%. Limiting toxicity syndromes 18%, 25% in young-elderly, all single site. Objective response rate intent-to-treat 94%. Sphinter preservation 87%, pCR 6%. After 17 months follow-up, progression-free survival and overall survival were not reached.

Conclusions

Oxaliplatin can be safely added to preoperative capecitabine-based chemoradiotherapy at the recommended dose 40 mg/m²/week, in LARC, with promising pCR and high activity.

Management of locally advanced rectal cancer in the elderly: a critical review and algorithm

Colorectal cancer incidence and death rates have been declining over the past 10 years. However, it remains the second leading cause of death in men ages 60-79 and the third leading cause of death in men over 80 and in women over 60 years old. However, there is little data specific to the treatment of the elder patient, since few of these patients are included in trials. With the advent of improved therapies, there are many alternative options available. Still, no definitive consensus or guidelines have been defined for this particular patient population. The goal of this study is to review the literature on the management of rectal cancer in the elderly and to propose treatment algorithms to help the oncology team in treatment decision-making.

Comparison of efficacy and safety of preoperative Chemoradiotherapy in locally advanced upper and middle/lower rectal cancer

Background

We aimed to explore the efficacy and safety profile of preoperative neoadjuvant chemoradiation (NACRT) in locally advanced rectal cancer (LARC) in upper rectum versus middle/lower rectum.

Methods

The study included 173 patients with stage II or III (T2-4b, N0-2b) LARC who underwent NACRT followed by total mesorectal excision (TME) between January 2011 and October 2016. Cox regression, log-rank test, and Kaplan–Meier curves were calculated.

Results

Among the 173 patients, 58 had lesions in the upper rectum and 115 patients had lesions in middle/lower rectum. In a median follow-up of 35 months (range, 6–73 months), the 5-year disease-free survival (DFS) and overall survival (OS) were 84% and 88% for the patients with upper rectal cancer and 77% and 68% for those with middle/lower rectal cancer (P = 0.251 and P = 0.058, respectively). The 5-year DFS (P = 0.012) and OS (P = 0.003) were better in the NACRT responders [tumor regression grade (TRG) 0 or 1] compared with nonresponders (TRG 2 or 3). The independent prognostic factor of favorable response to NACRT was the FOLFOX regimen (P = 0.004).

Conclusions

Patients with LARC in the upper rectum who underwent NACRT followed by TME had similar DFS and a trend toward longer OS, compared with those who had middle/lower rectal lesions. Furthermore, FOLFOX may yield superior results than fluoropyrimidine based regimen during NACRT. NACRT might be an alternative option for patients with LARC in the upper rectum as it has a favorable pathological complete response rate and comparable clinical outcomes when compared with patients with LARC in middle/lower rectum.

Meta-analysis of oxaliplatin-based versus fluorouracil-based neoadjuvant chemoradiotherapy and adjuvant chemotherapy for locally advanced rectal cancer

A meta-analysis was conducted to compare oxaliplatin-based with fluorouracil-based neoadjuvant chemoradiotherapy and adjuvant chemotherapy for locally advanced rectal cancer. MEDLINE, EMBASE and CENTRAL were systematically searched for relevant randomized controlled trials (RCTs) until January 31 2017. Review Manager (version 5.3) was used to analyze the data. Dichotomous data were calculated by odds ratio (OR) with 95% confidence intervals (CI). A total of 8 RCTs with 6103 stage II or III rectal cancer patients were analyzed, including 2887 patients with oxaliplatin+fluorouracil regimen and 3216 patients with fluorouracil alone regimen. Compared with fluorouracil-based regimen group, oxaliplatin-based regimen group attained higher pathologic complete response (OR = 1.29, 95% CI: 1.12−1.49, P = 0.0005) and 3-year disease-free survival (OR = 1.15, 95% CI: 0.93−1.42, P = 0.21), but suffered greater toxicity (OR = 2.07, 95% CI: 1.52−2.83, P < 0.00001). Also, there were no significant differences between two regimens in sphincter-sparing surgery rates (OR = 0.94, 95% CI: 0.83−1.06, P = 0.33), 5-year disease-free survival (OR = 1.15, 95% CI: 0.93−1.42, P = 0.21) and overall survival (3-year, OR = 1.14, 95% CI: 0.98−1.34, P = 0.09; 5-year, OR = 1.06, 95% CI: 0.78−1.44, P = 0.70). In conclusion, the benefits of adding oxaliplatin to fluorouracil-based neoadjuvant chemoradiotherapy and adjuvant chemotherapy for locally advanced rectal cancer remains controversial, and cannot be considered a standard approach.

Neoadjuvant Therapy in Rectal Cancer Patients With Clinical Stage II to III Across European Countries: Variations and Outcomes

BACKGROUND

Neoadjuvant therapy improves survival of patients with clinical stage II and III rectal cancer in clinical trials. In this study, we investigated the administration of neoadjuvant radiotherapy (neo-RT) and neoadjuvant chemoradiotherapy (neo-CRT) and its association with survival in resected patients in 2 European countries (The Netherlands and Sweden) and at 3 specialist centers.

MATERIALS AND METHODS

Administration of neoadjuvant treatment (all registries) and overall survival after surgery in The Netherlands and Sweden were assessed. Hazard ratios (HRs) were obtained using Cox regression adjusted for potential confounders.

RESULTS

A total of 16,095 rectal cancer patients with clinical stage II and III were eligible for analyses. Large variations in administration of neo-RT and neo-CRT were observed. Elderly patients less often received neo-RT and neo-CRT. Patients with stage III disease received neo-CRT more frequently than neo-RT. Administration of neo-RT versus surgery without neoadjuvant treatment was significantly associated with improved survival in The Netherlands (HR, 0.62; 95% confidence interval [CI], 0.53-0.73) as well as in Sweden (HR, 0.79; 95% CI, 0.69-0.90). Administration of neo-CRT was associated with enhanced survival in The Netherlands (HR, 0.62; 95% CI, 0.50-0.78) but not in Sweden (HR, 0.97; 95% CI, 0.80-1.18). The mortality of patients treated with neo-CRT compared with neo-RT showed inconsistent results in population-based centers.

CONCLUSIONS

Our results support an association of neo-RT with enhanced survival among stage II and III rectal cancer patients. Comparing neo-CRT with neo-RT, larger variations and inconsistent results with respect to survival were observed across centers.

DNA hypermethylation as a predictor of extramural vascular invasion (EMVI) in rectal cancer

PURPOSE

DNA hypermethylation in gene promoter regions (CpG islands) is emerging as an important pathway in colorectal cancer tumourigenesis. Whilst genetic mutations have been associated with extramural vascular invasion (EMVI) in rectal cancer, no such association has yet been made with epigenetic factors.

METHODS

100 consecutive neoadjuvant-naïve patients undergoing curative surgery for rectal were classified according to the presence or absence of EMVI on histopathological examination. DNA was extracted from tumours and subjected to bisulfite conversion and methylation-specific PCR to determine CIMP status (high, intermediate, or low; according to a validated panel of 8 genes). CIMP status was correlated with EMVI status, histopathological, clinical, and demographic variables, in addition to overall (OS) and disease free (DFS) survival.

RESULTS

51 patients were characterised as CIMP-low, 48 CIMP-intermediate, and one patient CIMP-high. EMVI-positivity was associated with CIMP-intermediate epigenotype (p < 0.001). Patients with EMVI-positive tumours were found to have significantly more advanced disease by pT, pN, and pAJCC categorisation (p = 0.002, p < 0.001, and = p < 0.001, respectively). EMVI-positivity was significantly associated with the requirement for adjuvant chemotherapy (p < 0.001), and worse DFS but not OS (p = 0.012 and p = 0.052).

CONCLUSIONS

Given the association between CIMP-intermediate epigenotype and EMVI-positivity, and the subsequent disadvantage in pathological stage, requirement for adjuvant therapy and worse survival, tumour epigenotyping could potentially play an important role in personalising patients' cancer care. Further work is required to understand the mechanisms that underlie the observed effect, with the hope that they may provide novel opportunities for intervention and inform treatment decisions in rectal cancer.

The role of chemotherapy in localized and locally advanced rectal cancer: A systematic revision

Curative treatment of rectal cancer depends on an optimal surgical resection, with the addition of neoadjuvant radiotherapy (RT) with or without concomitant chemotherapy (ChT) in more advanced tumors. The role of adjuvant ChT is controversial and a more intensified neoadjuvant approach with the addition of ChT before or after RT, or even as single modality, is currently being explored in trials. A systematic review selecting randomised phase II and III trials on the role of ChT in localized rectal cancer was performed. Data show that neoadjuvant ChRT improves locoregional control in resected rectal cancer. Short-course RT (SCRT) could give similar outcomes to ChRT. The addition of oxaliplatin to neoadjuvant ChRT marginally increases the pathological complete remission rate without improving survival and increasing toxicity. A more intensified approach remains investigational as trials to date have not shown significant advantages. Adjuvant ChT trials after preoperative ChRT are contentious, although the addition of oxaliplatin in high risk patients may benefit outcomes. Despite a wide heterogeneity in the target population, different staging procedures and diverse treatment approaches among different trials, this systematic review confirms the role of ChT in combination with neoadjuvant long-course RT. Adjuvant ChT could be of value in selected patients with high-risk features, mainly if they do not respond to neoadjuvant RT. Further investigation is warranted on more intensified neoadjuvant regimens including ChT for MRI-defined high-risk patients.

SERPINB5 Expression: Association with CCRT Response and Prognostic Value in Rectal Cancer

Background: Due to the varying characteristics and conflicting outcomes on the overall survival of rectal cancer patients, many studies have been undertaken to determine various prognostic and predictive factors for the mainstay treatment of CCRT followed by surgery. Cancer cell motility contributes to tumor invasion, migration and eventually metastasis. However, the genes associated with cell motility (i.e., GO:0048870) have not been systemically evaluated in rectal cancers. Methods: A comparative analysis of gene expression profiles was applied to the transcriptomic dataset (GSE35452) with a focus on genes associated with cell motility (GO:0048870), where SERPINB5 was recognized as the most significantly up-regulated gene. Tumor samples from 172 primary rectal cancer patients who underwent neoadjuvant CCRT followed by surgical resection were collected. Immunohistochemistry was used to semi-quantitatively assess the expression level of SERPINB5 protein. Statistical analyses of SERPINB5 expression and various clinicopathological features as well as survival were then performed. Results: High immunoreactivity of SERPINB5 was significantly linked to pre- and post-CCRT advanced disease, lymphovascular invasion, and poor response to CCRT (all P ≤ 0.015). SERPINB5 overexpression was not only negatively associated with disease-specific survival (DSS), local recurrence-free survival (LRFS) and metastasis-free survival (MeFS) rates in univariate analyses but also was an independent prognostic factor for DSS and MeFS in rectal cancer patients (all P ≤ 0.043). Conclusion: SERPINB5 may play an important role in rectal cancer progression and response to neoadjuvant CCRT and serve as a novel prognostic factor.

Robotic-assisted total mesorectal excision with the single-docking technique for patients with rectal cancer

Background

The robotic system has advantages of high-definition three-dimensional vision and articular instruments with high dexterity, allowing more precise dissection in the deep and narrow pelvic cavity.

Methods

We enrolled 95 patients with stage I-III rectal cancer (adenocarcinoma) who underwent totally robotic-assisted total mesorectal excision (TME) with single-docking technique at a single institution between September 2013 and December 2016.

Results

Of the 95 patients, 48 (50.5%) and 30 (31.6%) patients had lower and middle rectal cancers, respectively. Of the 75 (78.9%) patients undergoing preoperative concurrent chemoradiotherapy (CCRT), 27 (28.4%) exhibited pathologic complete response (pCR). Only four (4.2%) patients underwent abdominoperineal resection and the sphincter preservation rate was 95.8%. R0 resection was performed in 92 (96.8%) patients. Circumferential resection margin (CRM) and distal resection margin (DRM) were positive in 2 (2.1%) and 1 (1.1%) patients, respectively. The anastomotic leakage rate was 5.4% (5/95 patients). The overall complication rate was 17.9% (17/95 patients); most of them were mild. No 30-day hospital mortality occurred, and no patients required conversion to open surgery. In 92 patients undergoing R0 resection, 2-year overall survival was 94% and 2-year disease-free survival was 83%.

Conclusions

The results demonstrated that totally robotic-assisted TME with the single-docking technique is safe and feasible for patients with rectal cancer, with or without preoperative CCRT. Moreover, favorable pCR rate, R0 resection rate, CRM, DRM, sphincter preservation rate, and short-term oncological outcomes can be achieved by combining this approach with appropriate preoperative CCRT.

Effect of Neoadjuvant Chemoradiation Therapy on Proteasome Pool in Rectal Cancer

In untreated rectal cancer patients, the chymotrypsin-like activity of proteasomes in tumor tissue was 3-fold higher than that in conventionally normal tissue, which is explained by up-regulation of expression of immunoproteasomes and total pool of proteasomes. After neoadjuvant chemoradiation therapy, expressions of the total pool of proteasomes and immunoproteasomes in the tumor as well as the relative ratios of these indices to those in conventionally normal tissue were smaller by 1.4-3.3 times in comparison with the untreated patients. These changes were paralleled with pronounced (4.5-fold) down-regulation of proteasome activity in the tumor and a 3.7-fold decrease of activity ratio for the proteasomes in tumor and in conventionally normal tissue. The number of immunoproteasome subunits and the chymotrypsin-like activity of proteasomes can be viewed as potential markers to prognosticate effectiveness of neoadjuvant chemoradiation therapy in rectal cancer patients.

Study protocol: multi-parametric magnetic resonance imaging for therapeutic response prediction in rectal cancer

BACKGROUND

Response to neoadjuvant chemoradiotherapy (CRT) of rectal cancer is variable. Accurate imaging for prediction and early assessment of response would enable appropriate stratification of management to reduce treatment morbidity and improve therapeutic outcomes. Use of either diffusion weighted imaging (DWI) or dynamic contrast enhanced (DCE) imaging alone currently lacks sufficient sensitivity and specificity for clinical use to guide individualized treatment in rectal cancer. Multi-parametric MRI and analysis combining DWI and DCE may have potential to improve the accuracy of therapeutic response prediction and assessment.

METHODS

This protocol describes a prospective non-interventional single-arm clinical study. Patients with locally advanced rectal cancer undergoing preoperative CRT will prospectively undergo multi-parametric MRI pre-CRT, week 3 CRT, and post-CRT. The protocol consists of DWI using a read-out segmented sequence (RESOLVE), and DCE with pre-contrast T1-weighted (VIBE) scans for T1 calculation, followed by 60 phases at high temporal resolution (TWIST) after gadoversetamide injection. A 3-dimensional voxel-by-voxel technique will be used to produce colour-coded ADC and Ktrans histograms, and data evaluated in combination using scatter plots. MRI parameters will be correlated with surgical histopathology. Histopathology analysis will be standardized, with chemoradiotherapy response defined according to AJCC 7th Edition Tumour Regression Grade (TRG) criteria. Good response will be defined as TRG 0-1, and poor response will be defined as TRG 2-3.

DISCUSSION

The combination of DWI and DCE can provide information on physiological tumour factors such as cellularity and perfusion that may affect radiotherapy response. If validated, multi-parametric MRI combining DWI and DCE can be used to stratify management in rectal cancer patients. Accurate imaging prediction of patients with a complete response to CRT would enable a 'watch and wait' approach, avoiding surgical morbidity in these patients. Consistent and reliable quantitation from standardised protocols is essential in order to establish optimal thresholds of ADC and Ktrans and permit the role of multi-parametric MRI for early treatment prediction to be properly evaluated.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) number ACTRN12616001690448 (retrospectively registered 8/12/2016).

2017 update on the relationship between diabetes and colorectal cancer: epidemiology, potential molecular mechanisms and therapeutic implications

Worldwide deaths from diabetes mellitus (DM) and colorectal cancer increased by 90% and 57%, respectively, over the past 20 years. The risk of colorectal cancer was estimated to be 27% higher in patients with type 2 DM than in non-diabetic controls. However, there are potential confounders, information from lower income countries is scarce, across the globe there is no correlation between DM prevalence and colorectal cancer incidence and the association has evolved over time, suggesting the impact of additional environmental factors. The clinical relevance of these associations depends on understanding the mechanism involved. Although evidence is limited, insulin use has been associated with increased and metformin with decreased incidence of colorectal cancer. In addition, colorectal cancer shares some cellular and molecular pathways with diabetes target organ damage, exemplified by diabetic kidney disease. These include epithelial cell injury, activation of inflammation and Wnt/β-catenin pathways and iron homeostasis defects, among others. Indeed, some drugs have undergone clinical trials for both cancer and diabetic kidney disease. Genome-wide association studies have identified diabetes-associated genes (e.g. TCF7L2) that may also contribute to colorectal cancer. We review the epidemiological evidence, potential pathophysiological mechanisms and therapeutic implications of the association between DM and colorectal cancer. Further studies should clarify the worldwide association between DM and colorectal cancer, strengthen the biological plausibility of a cause-and-effect relationship through characterization of the molecular pathways involved, search for specific molecular signatures of colorectal cancer under diabetic conditions, and eventually explore DM-specific strategies to prevent or treat colorectal cancer.

The Impact of Novel Radiation Treatment Techniques on Toxicity and Clinical Outcomes In Rectal Cancer

Purpose of review

Three-dimensional conformal radiation therapy (3DCRT) has been the standard technique in the treatment of rectal cancer. The use of new radiation treatment technologies such as intensity-modulated radiation therapy (IMRT), proton therapy (PT), stereotactic body radiation therapy (SBRT) and brachytherapy (BT) has been increasing over the past 10 years. This review will highlight the advantages and drawbacks of these techniques.

Recent findings

IMRT, PT, SBRT and BT achieve a higher target coverage conformity, a higher organ at risk sparing and enable dose escalation compared to 3DCRT. Some studies suggested a reduction in gastrointestinal and hematologic toxicities and an increase in the complete pathologic response rate; however, the clinical benefit of these techniques remains controversial.

Summary

The results of these new techniques seem encouraging despite conclusive data. Further trials are required to establish their role in rectal cancer.

Tailored Treatment of Colorectal Cancer: Surgical, Molecular, and Genetic Considerations

Colorectal cancer (CRC) is a complex cancer disease, and approximately 40% of the surgically cured patients will experience cancer recurrence within 5 years. During recent years, research has shown that CRC treatment should be tailored to the individual patient due to the wide variety of risk factors, genetic factors, and surgical complexity. In this review, we provide an overview of the considerations that are needed to provide an individualized, patient-tailored treatment. We emphasize the need to assess the predictors of CRC, and we summarize the latest research on CRC genetics and immunotherapy. Finally, we provide a summary of the significant variations in the colon and rectal anatomy that is important to consider in an individualized surgical approach. For the individual patient with CRC, a tailored treatment approach is needed in the preoperative, operative, and postoperative phase.

Gastrointestinal cancers in India: Treatment perspective

GI cancer is not one cancer but is a term for the group of cancers that affect the digestive system including gastric cancer (GC), colorectal cancer (CRC), hepatocellular carcinoma (HCC), esophageal cancer (EC), and pancreatic cancer (PC). Overall, the GI cancers are responsible for more cancers and more deaths from cancer than any other organ. 5 year survival of these cancers remains low compared to western world. Unlike the rest of the world where organ based specialities hepatobiliary, pancreatic, colorectal and esophagogastric exist, these cancers are managed in India by either a gastrointestinal surgeons, surgical oncologist, or a general surgeon with varying outcomes. The aim of this review was to collate data on GI cancers in indian continent. In colorectal cancers, data from tertiary care centres identifies the unique problem of mucinous and signet colorectal cancer. Results of rectal cancer resection in terms of technique (intersphincteric resection, extralevator aper, minimal invasive approach) to be comparable with world literature. However long term outcome and data regarding colon cancers and nationally is needed. Gastric cancer at presentation are advanced and in surgically resected patients, there is need for a trial to compare chemoradiation vs chemotherapy alone to prevent loco regional recurrence. Data on minimal invasive gastric cancer surgery may be sparse for the same reason. Theree is a lot of data on surgical techniques and perioperatve outcomes in pancreatic cancer. There is a high volume of locally advanced gallbladder cancers with efforts on to decide whether neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy is better for down staging. Considering GI cancers, a heterogeneous disease with site specific treatment options and variable outcomes, the overall data and outcomes are extremely variable. Young patients with pathology unique to the Indian subcontinent (for example, signet ring rectal cancer, GBCs) need focussed attention. Solution for such pathology needs to come from the Indian continent itself. Joint efforts to improve outcomes for GI cancer can be integrated under the national cancer grid program.

Radiotherapy for Colorectal Cancer: Current Standards and Future Perspectives

BACKGROUND

Multimodal treatment approaches are indispensable for patients with advanced-stage colorectal cancer. Radiotherapy has been established as essential part of perioperative concepts and was introduced as an option to face challenges such as local relapse or oligometastases.

METHODS

A literature review was performed to summarize evidence and current standards of radiotherapeutic concepts in the treatment of colorectal cancer.

RESULTS

For stage II/III rectal cancer, neoadjuvant radiotherapy is superior to adjuvant treatment. Two preoperative regimens have been established and are commonly used with different objectives: short-course radiotherapy (SC-RT) and long-course chemoradiotherapy (LC-CRT). Both reduce the risk of local relapse. Additionally, LC-CRT aims at downsizing the tumor to potentially reduce radicalness of surgery. There is increasing evidence that not all stage II/III rectal cancer patients need neoadjuvant irradiation but also that in some cases surgery might be omitted. Stereotactic body radiotherapy (SBRT) of the liver shows high rates of local control in oligometastatic patients. Intraoperative and particle radiotherapy extend the spectrum of treatment options for locally recurrent patients.

CONCLUSION

Radiotherapeutic concepts are crucial for the primary management of locally advanced colorectal cancer and can essentially contribute to treatment approaches in locally recurrent, oligometastatic or palliative patients.

Restaging after neoadjuvant chemoradiation in rectal cancers: is histology the key in patient selection?

BACKGROUND

Neoadjuvant chemoradiation is the standard of care for locally advanced rectal cancer. However, there is no clarity regarding the necessity for restaging scans to rule out systemic progression of disease post chemoradiation with existing literature being divided on the need for the same.

METHODS

Data from a prospectively maintained database was retrospectively analysed. All locally advanced rectal cancers (node positive/T4/T3 with threatened or involved CRM) were included. Biopsy proof of adenocarcinoma and CT scan of abdomen and chest were mandatory. Grade of tumor and response to CTRT on restaging magnetic resonance imaging (MRI) were documented.

RESULTS

Out of 119 patients subjected to CTRT, 72 underwent definitive total mesorectal excision while 13 patients progressed locoregionally on restaging MR pelvis and 15 other patients progressed systemically while the rest defaulted. Patients with poorly differentiated (PD) cancers were compared to those with well/moderately differentiated (WMD) tumors. PD tumors had a significantly higher rate of local progression (32.1% vs. 5.6% %, P=0.0011) and systemic progression (35.7% vs. 6.9%, P=0.0008) as compared to WMD tumors. Only one-third (9/28) of PD patients underwent TME while the rest progressed.

CONCLUSIONS

Selecting poorly differentiated tumors alone for restaging CECT abdomen and thorax will be a cost effective strategy as the rate of progression is very high. Also patients with PD tumors need to be consulted about the high probability of progression of disease.

Drug Combinations in Preoperative Chemoradiation for Rectal Cancer

Preoperative radiotherapy has an accepted role in reducing the risk of local recurrence in locally advanced resectable rectal cancer, particularly when the circumferential resection margin is breached or threatened, according to magnetic resonance imaging. Fluoropyrimidine-based chemoradiation can obtain a significant down-sizing response and a curative resection can then be achieved. Approximately, 20% of the patients can also obtain a pathological complete response, which is associated with less local recurrences and increased survival. Patients who achieve a sustained complete clinical response may also avoid radical surgery. In unresectable or borderline resectable tumors, around 20% of the patients still fail to achieve a sufficient down-staging response with the current chemoradiation schedules. Hence, investigators have aspired to increase pathological complete response rates, aiming to improve curative resection rates, enhance survival, and potentially avoid mutilating surgery. However, adding additional cytotoxic or biological agents have not produced dramatic improvements in outcome and often led to excess surgical morbidity and higher levels of acute toxicity, which effects on compliance and in the global efficacy of chemoradiation.

Is Preoperative Chemoradiotherapy Beneficial for Sphincter Preservation in Low-Lying Rectal Cancer Patients?

The present study explored the benefit of preoperative chemoradiotherapy (PCRT) for sphincter preservation in locally advanced low-lying rectal cancer patients who underwent stapled anastomosis, especially in those with deep and narrow pelvises determined by magnetic resonance imaging.Patients with locally advanced low-lying rectal cancer (≤5 cm from the anal verge) who underwent stapled anastomosis were included. Patients were categorized into two groups (PCRT+ vs. PCRT-) according to PCRT application. Patients in the PCRT+ group were matched to those in the PCRT- group according to potential confounding factors (age, gender, clinical stage, and body mass index) for sphincter preservation. Sphincter preservation, permanent stoma, and anastomosis-related complications were compared between the groups. Pelvic magnetic resonance imaging was used to measure 12 dimensions representing pelvic cavity depth and width with which deep and narrow pelvis was defined. The impact of PCRT on sphincter preservation and permanent stoma in pelvic dimensions defined as deep and narrow pelvis was evaluated, and factors associated with sphincter preservation and permanent stoma were analyzed.One hundred sixty-six patients were one-to-one matched between the PCRT+ and PCRT- groups. Overall, sphincter-saving surgery was performed in 66.3% and the rates were not different between the 2 groups. Anastomotic complications and permanent stoma occurred nonsignificantly more frequently in the PCRT+ group. PCRT was not associated with higher rate of sphincter preservation in all pelvic dimensions defined as deep and narrow pelvis, while PCRT was related to higher rate of permanent stoma in shorter transverse diameter and interspinous distance. On logistic regression analysis, PCRT was not shown to influence both sphincter preservation and permanent stoma, while longer transverse diameter and interspinous distance were associated with lower rate of permanent stoma.PCRT had no beneficial effect on sphincter preservation in patients with locally advanced low-lying rectal cancer who had undergone stapled anastomosis. In patients with deep and narrow pelvis, PCRT had no impact on sphincter preservation but was associated with higher rate of permanent stoma.

Pelvic radiotherapy and sexual function in women

BACKGROUND

During the past decade there has been considerable progress in developing new radiation methods for cancer treatment. Pelvic radiotherapy constitutes the primary or (neo) adjuvant treatment of many pelvic cancers e.g., locally advanced cervical and rectal cancer. There is an increasing focus on late effects and an increasing awareness that patient reported outcomes (PROs) i.e., patient assessment of physical, social, psychological, and sexual functioning provides the most valid information on the effects of cancer treatment. Following cure of cancer allow survivors focus on quality of life (QOL) issues; sexual functioning has proved to be one of the most important aspects of concern in long-term survivors.

METHODS

An updated literature search in PubMed was performed on pelvic radiotherapy and female sexual functioning/dysfunction. Studies on gynaecological, urological and gastrointestinal cancers were included. The focus was on the period from 2010 to 2014, on studies using PROs, on potential randomized controlled trials (RCTs) where female sexual dysfunction (FSD) at least constituted a secondary outcome, and on studies reporting from modern radiotherapy modalities.

RESULTS

The literature search revealed a few RCTs with FSD evaluated as a PRO and being a secondary outcome measure in endometrial and in rectal cancer patients. Very limited information could be extracted regarding FSD in bladder, vulva, and anal cancer patients. The literature before and after 2010 confirms that pelvic radiotherapy, independent on modality, increases the risk significantly for FSD both compared to data from age-matched healthy control women and compared to data on patients treated by surgery only. There was only very limited data available on modern radiotherapy modalities. These are awaited during the next five years. Several newer studies confirm that health care professionals are still reluctant to discuss treatment induced sexual dysfunction with patients.

CONCLUSIONS

Pelvic radiotherapy has a persistent deteriorating effect on the vaginal mucosa impacting negatively on the sexual functioning in female cancer patients. Hopefully, modern radiotherapy modalities will cause less vaginal morbidity but results are awaited to confirm this assumption. Health care professionals are encouraged to address potential sexual dysfunction both before and after radiotherapy and to focus more on quality than on quantity.

The effects of neoadjuvant chemoradiotherapy and an in-hospital exercise training programme on physical fitness and quality of life in locally advanced rectal cancer patients (The EMPOWER Trial): study protocol for a randomised controlled trial

BACKGROUND

The standard treatment pathway for locally advanced rectal cancer is neoadjuvant chemoradiotherapy (CRT) followed by surgery. Neoadjuvant CRT has been shown to decrease physical fitness, and this decrease is associated with increased post-operative morbidity. Exercise training can stimulate skeletal muscle adaptations such as increased mitochondrial content and improved oxygen uptake capacity, both of which are contributors to physical fitness. The aims of the EMPOWER trial are to assess the effects of neoadjuvant CRT and an in-hospital exercise training programme on physical fitness, health-related quality of life (HRQoL), and physical activity levels, as well as post-operative morbidity and cancer staging.

METHODS/DESIGN

The EMPOWER Trial is a randomised controlled trial with a planned recruitment of 46 patients with locally advanced rectal cancer and who are undergoing neoadjuvant CRT and surgery. Following completion of the neoadjuvant CRT (week 0) prior to surgery, patients are randomised to an in-hospital exercise training programme (aerobic interval training for 6 to 9 weeks) or a usual care control group (usual care and no formal exercise training). The primary endpoint is oxygen uptake at lactate threshold ([Formula: see text] at [Formula: see text]) measured using cardiopulmonary exercise testing assessed over several time points throughout the study. Secondary endpoints include HRQoL, assessed using semi-structured interviews and questionnaires, and physical activity levels assessed using activity monitors. Exploratory endpoints include post-operative morbidity, assessed using the Post-Operative Morbidity Survey (POMS), and cancer staging, assessed by using magnetic resonance tumour regression grading.

DISCUSSION

The EMPOWER trial is the first randomised controlled trial comparing an in-hospital exercise training group with a usual care control group in patients with locally advanced rectal cancer. This trial will allow us to determine whether exercise training following neoadjuvant CRT can improve physical fitness and activity levels, as well as other important clinical outcome measures such as HRQoL and post-operative morbidity. These results will aid the design of a large, multi-centre trial to determine whether an increase in physical fitness improves clinically relevant post-operative outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01914068 (received: 7 June 2013).

SPONSOR

University Hospital Southampton NHS Foundation Trust.

Adjuvant versus neoadjuvant chemoradiotherapy in distal rectal cancer: Comparison of two decades in a single center

OBJECTIVE

Standard surgery alone was not able to decrease local recurrence (LR) rate below 20% in rectal cancer treatment. Thus, many centers administered neoadjuvant radiotherapy (preopRTx) with or without concomitant chemotherapy for the prevention of LR. In this study, the results of 164 consecutive patients with mid- and distal rectal cancer who received surgery and adjuvant chemoradiotherapy (Group A) or neoadjuvant chemoradiotherapy (Group NA) followed by surgery are presented.

MATERIAL AND METHODS

The staging system used in this study is that of the American Joint Committee on Cancer (AJCC), also known as the TNM system. Eligible patients were required to have radiologically assessed stage 1 (only T2N0M0) to stage 3C (T4bN1-2M0) tumor with pathologically confirmed R0 resection. The surgical method was total mesorectal excision (TME). Radiotherapy was applied with daily 180 cGy fractions for 28 consecutive days. Chemo-therapy comprised 5-fluorouracil (450 mg/m(2)/d) and leucovorin (20 mg/m(2)/d) bolus at days 1-5 and 29-33.

RESULTS

Nine patients (13%) in Group NA achieved pathologic complete response (pCR). In Group NA and Group A, locoregional recurrence (LRR) rates were 6.7% and 30.8%, (p<0.001), the mean LR-free survival was 190.0±7.3 months and 148.0±11.7 months (p=0.002) and the mean overall survival (OS) was 119.2±15.3 months and 103.0±9.4 months (p=0.23), respectively. A significant difference with regard to LR has been obtained with a statistical power of 0.92. Secondary outcome measures (DFS and OS) have not been met.

CONCLUSION

Neoadjuvant chemoradiotherapy with TME is an efficient treatment protocol, particularly for the treatment of magnetic resonance imaging-staged 2A to 3C patients with two or three distal rectal adenocarcinomas. Given that a considerable proportion of patients with cT2N0M0 would develop pCR, this method of treatment can be considered for further studies.