Effect of preoperative radio(chemo)therapy on long-term functional outcome in rectal cancer patients: a systematic review and meta-analysis

The Landmark Series: Neoadjuvant Therapy for Locally Advanced Rectal Cancer

The management of locally advanced rectal cancer (LARC) has seen much development over recent decades. Neoadjuvant radiotherapy combined with high-quality total mesorectal excision saw improvements in locoregional control. With the advent of several key trials, neoadjuvant therapy for LARC has seen a shift toward total neoadjuvant therapy, with corresponding improvements in tumor response and survival outcomes. The collective pool of evidence has allowed for increasingly personalized treatment of LARC, with organ-preservation now an option for many. The aims of the review are to summarize the evolution of neoadjuvant therapy for LARC, highlight key studies informing contemporary best practices, navigate the complexity of options available, and present areas of ongoing development.

Comparison of the efficacy of neoadjuvant chemotherapy and neoadjuvant chemoradiotherapy in locally advanced rectal cancer patients: meta-analysis of randomized controlled trials

BACKGROUND

Preoperative neoadjuvant chemoradiotherapy (nCRT) is considered to be the standard treatment strategy for locally advanced rectal cancer (LARC); however, the risk of adverse events and postoperative recurrence remains significant. This study aimed to evaluate the non-inferiority of neoadjuvant chemotherapy (nCT) compared with nCRT in patients with LARC and to assess the possibility of eliminating radiotherapy on the basis of guaranteed efficacy.

MATERIALS AND METHODS

We searched the PubMed, Embase, and Cochrane Library databases to identify randomized controlled trials (RCTs) comparing the efficacy of nCRT and nCT for LARC. The study protocol was registered with the Prospective Register of Systematic Reviews (PROSPERO).

RESULTS

A total of 2706 patients from seven studies were included in the meta-analysis. There was no significant difference in overall survival (OS) or disease-free survival (DFS) between the nCT and nCRT groups. This study demonstrated a lower rate of infection (OR = 0.53, 95% CI = 0.34-0.82; P = 0.005), anastomotic leak (OR = 0.55, 95% CI = 0.34-0.87; P = 0.01), tumor regression grade (TRG) 0-1 (OR = 0.50, 95% CI = 0.36-0.69; P < 0.0001), preventive diverting ileostomy (OR = 0.41, 95% CI = 0.17-1.02; P = 0.05), and leukopenia (OR = 0.50, 95% CI = 0.25-1.01; P = 0.05) in the nCT group. However, there was no significant difference in the other toxic events, such as intestinal obstruction, urinary complications, diarrhea, and surgical or pathological outcomes, such as clinical fistula, sphincter preservation, postoperative mortality (≤ 60 d), R0 resection, ypStage 0-I, positive circumferential resection margin (CRM+), or pathological complete response (pCR) between the two groups.

CONCLUSION

This study indicated that OS and DFS were not lower in the nCT group than in the nCRT group. In addition, the nCT group had fewer complications. Preoperative nCT is expected to become a standard treatment option for most patients with stage II-III LARC. It is worth noting that radiotherapy cannot be ignored for some patients who need to ensure the conversion effect of neoadjuvant therapy and strongly request to preserve organ function.

Prediction of anorectal dysfunction in the combined treatment of rectal cancer

AIM: to assess the risk of severe low anterior resection syndrome (LARS) in patients with rectal cancer after combined treatment.

PATIENTS AND METHODS: from July 2022 to November 2023, 50 patients with rectal cancer underwent radiation with a total focal dose of 50–54 Gy with radiomodification with capecitabine and low anterior rectal resection with preventive ileostomy. The ileostomy was closed after 4 months. Prior to and after radiation, the anorectal function was assessed using high-resolution anorectal manometry (HRAM) and the LARS scale.

RESULTS: the most significant predicting factors for severe LARS were maximal contraction pressure and first sensation volume. Three months after ileostomy closure, the patients were divided into groups depending on the HRAM parameters. Group 1: nine patients with severe LARS (34 points on the LARS scale), with a decrease in maximal contraction pressure by ≥ 30% and an increased first sensation volume by ≥ 60%, according to HRAM. Group 2: four patients out of 36 had severe LARS (31 points on the LARS scale), with a decrease in maximal contraction pressure by 5–29% and an increased first sensation volume by 10–59%, according to HRAM. Group 3: in 5 patients with a decreased maximal contraction pressure by ≤ 4% and an increased volume of the first sensation by ≤ 9%, LARS did not develop.

CONCLUSION: a decrease in the maximal contraction pressure by 30% or more and an increase in the volume of the first sensation by 60% or more after radiation therapy can increase the risk of severe LARS. This group of patients requires prevention and correction of anorectal dysfunction.

Effect of neoadjuvant chemoradiation on anorectal function assessed with anorectal manometry: A systematic review and meta-analysis

AIM

Improvement in oncological survival for rectal cancer increases attention to anorectal dysfunction. Diagnostic questionnaires can evaluate quality of life but are subjective and dependent on patients' compliance. Anorectal manometry can objectively assess the continence mechanism and identify functional sphincter weakness and rectal compliance. Neoadjuvant chemoradiotherapy is presumed to affect anorectal function. We aim to assess anorectal function in rectal cancer patients who undergo total mesorectal excision, with or without neoadjuvant chemoradiation, using anorectal manometry measurements.

METHOD

MEDLINE, Embase, and Cochrane databases were searched for studies comparing perioperative anorectal manometry between neoadjuvant chemoradiation and upfront surgery for rectal cancers. Primary outcomes were resting pressure, squeeze pressure, sensory threshold volume and maximal tolerable volume.

RESULTS

Eight studies were included in the systematic review, of which seven were included for metanalysis. 155 patients (45.3%) had neoadjuvant chemoradiation before definitive surgery, and 187 (54.6%) underwent upfront surgery. Most patients were male (238 vs. 118). The standardized mean difference of mean resting pressure, mean and maximum squeeze pressure, maximum resting pressure, sensory threshold volume, and maximal tolerable volume favored the upfront surgery group but without statistical significance.

CONCLUSION

Currently available evidence on anorectal manometry protocols failed to show any statistically significant differences in functional outcomes between neoadjuvant chemoradiation and upfront surgery. Further large-scale prospective studies with standardized neoadjuvant chemoradiation and anorectal manometry protocols are needed to validate these findings.

Impact of neoadjuvant immunotherapy on postoperative complications after surgery for rectal cancer

INTRODUCTION

Despite the increasing use of immunotherapy in treating various cancer types, there is still limited understanding of its impact on surgical complications. We used a national database to examine the difference in surgical outcomes for rectal cancer patients who received standard neoadjuvant chemoradiation plus neoadjuvant immunotherapy and patients who received neoadjuvant chemoradiation only.

METHODS

This retrospective cohort study used the National Cancer Database (NCDB). We selected patients aged 18-90 with T1-3, N1-2, and M0 rectal cancer who underwent curative-intent surgery between 2010 and 2020. We performed a 1:1 propensity match to control for patient age, sex, Charlson-Deyo comorbidity index, surgical approach, and tumor site. Our primary outcome was difference in surgical outcomes (hospital length of stay, unplanned 30-day readmission, 30-day mortality) between the two groups. Secondary outcomes included days from diagnosis to surgery and pathologic outcomes.

RESULTS

Our study included 26 229 patients, of which 126 received immunotherapy in addition to chemoradiation and 26 103 received only chemoradiation. In our matched population of 125 pairs of patients, patients who received immunotherapy and chemoradiation underwent surgery later compared to patients who only received chemoradiation (median 245 vs. 144 days, p < 0.001). There were no significant differences in median length of stay (5 vs. 5 days, p = 0.202), unplanned 30-day readmission (7 vs. 9, p = 0.617), and 30-day mortality (0 vs. 1, p = 1.000) between the two groups.

CONCLUSION

Neoadjuvant immunotherapy for rectal cancer is not associated with adverse surgical outcomes. This work can help clinicians optimize treatment protocols and move closer toward strategies tailored to specific patient profiles.

Long-term outcomes of sacral neuromodulation for low anterior resection syndrome after rectal cancer surgery

PURPOSE

This study assessed the long-term outcomes and quality of life in patients who underwent sacral neuromodulation (SNM) due to low anterior resection syndrome (LARS).

METHODS

This single-center retrospective study, conducted from 2005 to 2021, included 30 patients (21 men; median age, 70 years) who had undergone total mesorectal excision with stoma closure and had no recurrence at inclusion. All patients were diagnosed with LARS refractory to conservative treatment. We evaluated clinical and quality-of-life outcomes after SNM through a stool diary, Wexner score, LARS score, the Fecal Incontinence Quality of Life (FIQL) questionnaire, and EuroQol-5D (EQ-5D) questionnaire.

RESULTS

Peripheral nerve stimulation was successful in all but one patient. Of the 29 patients who underwent percutaneous nerve evaluation, 17 (58.62%) responded well to SNM and received permanent implants. The median follow-up period was 48 months (range, 18-153 months). The number of days per week with fecal incontinence episodes decreased from a median of 7 (range, 2-7) to 0.38 (range, 0-1). The median number of bowel movements recorded in patient diaries fell from 5 (range, 4-12) to 2 (range, 1-6). The median Wexner score decreased from 18 (range, 13-20) to 6 (range, 0-16), while the LARS score declined from 38.5 (range, 37-42) to 19 (range, 4-28). The FIQL and EQ-5D questionnaires demonstrated enhanced quality of life.

CONCLUSION

SNM may benefit patients diagnosed with LARS following rectal cancer surgery when conservative options have failed, and the treatment outcomes may possess long-term sustainability.

Do treated rectal tumors appear differently on MRI after chemotherapy versus chemoradiotherapy?

PURPOSE

Increasing studies have focused on neoadjuvant chemotherapy (NCT) in rectal cancer. However, few studies explored the differences in radiographic variation between patients treated with NCT and neoadjuvant chemoradiotherapy (NCRT).

METHODS

Stage II/III rectal cancer patients from March 2016 to December 2019 meeting the criteria treated with NCRT or NCT were included. MRI features, including tumor location, longitudinal length, DWI signal, MRI tumor regression grade (mrTRG), and radiomic texture features, before and after neoadjuvant treatments were reviewed.

RESULTS

116 patients with NCRT and 61 with NCT were analyzed. Among these patients, 46 patients in the NCRT group and 18 in the NCT group were responders with pathological TRG0-1. Within these responders, the mean tumor longitudinal length regression rate (TLRR) of the NCT group was 60.08 ± 11.17%, which was significantly higher than the 50.73 ± 15.28% of the NCRT group (p = 0.010). The proportion of high signal in the DWI image after NCT was higher than that of the NCRT group (88.89% vs 50.00%, p = 0.004). NCT responders had significantly higher median change rates than those of NCRT responders in 11 radiomic features, especially those shape features.

CONCLUSION

MRI images change differently between responders treated with NCRT and those with NCT in rectal cancer. The tumor volumetry and some radiomic features change more obviously in NCT responders, and the tumor signal changes more obviously in NCRT responders. During the evaluation of the response of the tumor to the neoadjuvant treatments, images of patients should be treated differently.

Comparison of the Colonic J-Pouch Versus Side-To-End Anastomosis Following Low Anterior Resection: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this systematic review and meta-analysis is to evaluate clinical, functional, and anorectal physiology outcomes of the side-to-end vs colonic J-pouch (CJP) anastomosis following anterior resection for rectal cancer.

METHODS

A PRISMA-compliant systematic review and meta-analysis was conducted using multiple electronic databases and clinical trial registers and all studies comparing side-to-end vs CJP anastomosis were included. Peri-operative complications, mortality rate, functional bowel, and anorectal outcomes were evaluated.

RESULTS

Eight randomized controlled trials (RCTs) and two observational studies with 1125 patients (side-to-end: n = 557; CJP: n = 568) were included. Of the entire functional bowel outcome parameters analyzed, only the sensation of incomplete bowel evacuation was significant in the CJP group at 6 months [OR: 2.07; 95% CI 1.06 - 4.02, P = .03]. Peri- and post-operative clinical parameters were comparable in both groups (total operative time, intra-operative blood loss, anastomotic leak rate, return to theater, anastomotic stricture formation and mortality). Equally, most of the analyzed anorectal physiology parameters (anorectal volume, anal squeeze pressure, maximum anal volume) were not significantly different between the two groups. However, anal resting pressure (mmHg) 2 years post-operatively was noted to be significantly higher in the side-to-end group than that of the CJP configuration [MD: -8.76; 95% CI - 15.91 - 1.61, P = .02].

DISCUSSION

Clinical and functional outcomes following CJP surgery and side-to-end coloanal anastomosis are comparable. Neither technique appears to proffer solution to low anterior resection syndrome in the short term but future well-designed; high-quality RCTs with long term follow-up are required.

Computed Diffusion-Weighted Images of Rectal Cancer: Image Quality, Restaging, and Treatment Response after Neoadjuvant Therapy

BACKGROUND

Computed diffusion-weighted images (cDWI) of random b value could be derived from acquired DWI (aDWI) with at least two different b values. However, its comparison between aDWI and cDWI images in locally advanced rectal cancer (LARC) patients after neoadjuvant therapy (NT) is needed.

PURPOSE

To compare the cDWI and aDWI in image quality, restaging, and treatment response of LARC after NT.

STUDY TYPE

Retrospective.

POPULATION

Eighty-seven consecutive patients.

FIELD STRENGTH/SEQUENCE

3.0 T/DWI.

ASSESSMENT

All patients underwent two DWI sequences, including conventional acquisition with b = 0 and 1000 s/mm2 (aDWIb1000 ) and another with b = 0 and 700 s/mm2 on a 3.0-T MR scanner. The images of the latter were used to compute the diffusion images with b = 1000 s/mm2 (cDWIb1000 ). Four radiologists with 3, 4, 14, and 25 years of experience evaluated the images to compare the image quality, TN restaging performance, and treatment response between aDWIb1000 and cDWIb1000 .

STATISTICAL TESTS

Interclass correlation coefficients, weighted κ coefficient, paired Wilcoxon, and McNemar or Fisher test were used. A significance level of 0.05 was used.

RESULTS

The cDWIb1000 images were superior to the aDWIb1000 ones in both subjective and objective image quality. In T restaging, the overall diagnostic accuracy of cDWIb1000 images was higher than that of aDWIb1000 images (57.47% vs. 49.43%, P = 0.289 for the inexperienced radiologist; 77.01% vs. 63.22%, significant for the experienced radiologist), with better sensitivity in determining ypT0-Tis tumors. Additionally, it increased the sensitivity in detecting ypT2 tumors for the inexperienced radiologist and ypT3 tumors for the experienced radiologist. N restaging and treatment response were found to be similar between two sequences for both radiologists.

DATA CONCLUSION

Compared to aDWIb1000 images, the computed ones might serve as a wise approach, providing comparable or better image quality, restaging performance, and treatment response assessment for LARC after NT.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

Low anterior resection syndrome and quality of life after intersphincteric resection for rectal cancer: a propensity score-matched study

PURPOSE

Our aim was to perform a propensity score-matched study to compare the long-term functional outcomes and quality of life following intersphincteric resection vs. low anterior resection (LAR) with very low anastomosis.

METHODS

Patients who underwent intersphincteric resection or low anterior resection with low anastomosis (≤ 4 cm from the anal verge) for rectal cancer between January 2017 and June 2020 were retrospectively included. A propensity score-matching process was performed. Functional outcomes and quality of life were assessed using the European Quality of Life 5 Dimensions 3 Level Version (EQ-5D-3L), EORC-QLQ C30, EORC-QLQ CR29, Low Anterior Resection Syndrome (LARS), Wexner, and International Prostate Symptom Score (IPSS) questionnaires. The primary outcome was the presence of LARS at least 12 months after surgery. The second outcome was the postoperative quality of life of included patients.

RESULTS

After propensity matching, 128 patients were included, including 58 males and 70 females with a median age of 59.5. Patients in the intersphincteric resection group showed a higher incidence of incontinence to flatus (32.8% versus 14.0%, p = 0.043) and stools (42.2% versus 21.9%, p = 0.046), pain/discomfort (25.0% versus 7.8%, p = 0.001), and bowel dysfunction, while the LARS scores (15.0 versus 13.2, p = 0.461) and major LARS rates (26.6% versus 14.1%, p = 0.078) were comparable in both groups.

CONCLUSION

ISR leads to increased bowel incontinence rate and increased anal pain, without affecting the grade of low anterior resection syndrome, fecal urgency, and clustering. LAR might be the preferred sphincteric-preserving approach when negative resection margins and a safe anastomosis are guaranteed. Patients should be fully informed about potential functional impairment after sphincter-preservation procedures.

Data-Independent Acquisition Mass Spectrometry Analysis of FFPE Rectal Cancer Samples Offers In-Depth Proteomics Characterization of the Response to Neoadjuvant Chemoradiotherapy

Locally advanced rectal cancer (LARC) presents a challenge in identifying molecular markers linked to the response to neoadjuvant chemoradiotherapy (nCRT). This study aimed to utilize a sensitive proteomic method, data-independent mass spectrometry (DIA-MS), to extensively analyze the LARC proteome, seeking individuals with favorable initial responses suitable for a watch-and-wait approach. This research addresses the unmet need to understand the response to treatment, potentially guiding personalized strategies for LARC patients. Post-treatment assessment included MRI scans and proctoscopy. This research involved 97 LARC patients treated with intense chemoradiotherapy, comprising radiation and chemotherapy. Out of 97 LARC included in this study, we selected 20 samples with the most different responses to nCRT for proteome profiling (responders vs. non-responders). This proteomic approach shows extensive proteome coverage in LARC samples. The analysis identified a significant number of proteins compared to a prior study. A total of 915 proteins exhibited differential expression between the two groups, with certain signaling pathways associated with response mechanisms, while top candidates had good predictive potential. Proteins encoded by genes SMPDL3A, PCTP, LGMN, SYNJ2, NHLRC3, GLB1, and RAB43 showed high predictive potential of unfavorable treatment outcome, while RPA2, SARNP, PCBP2, SF3B2, HNRNPF, RBBP4, MAGOHB, DUT, ERG28, and BUB3 were good predictive biomarkers of favorable treatment outcome. The identified proteins and related biological processes provide promising insights that could enhance the management and care of LARC patients.

Interaction between intratumoral microbiota and tumor mediates the response of neoadjuvant therapy for rectal cancer

Background

Previous observations have demonstrated that the response to neoadjuvant chemoradiotherapy (nCRT) is highly variable in patients with locally advanced rectal cancer (LARC). Recent studies focusing on the intratumoral microbiota of colorectal cancer have revealed its role in oncogenesis and tumor progression. However, limited research has focused on the influence of intratumoral microbiota on the nCRT of LARC.

Methods

We explored the microbial profiles in the tumor microenvironment of LARC using RNA-seq data from a published European cohort. Microbial signatures were characterized in pathological complete response (pCR) and non-pCR groups. Multi-omics analysis was performed between intratumor microbiomes and transcriptomes.

Results

Microbial α and β diversity were significantly different in pCR and non-pCR groups. Twelve differential microbes were discovered between the pCR and non-pCR groups, six of which were related to subclusters of cancer-associated fibroblasts (CAFs) associated with extracellular matrix formation. A microbial risk score based on the relative abundance of seven differential microbes had predictive value for the nCRT response (AUC = 0.820, p < 0.001).

Conclusion

Our study presents intratumoral microbes as potential independent predictive markers for the response of nCRT to LARC and demonstrates the underlying mechanism by which the interaction between intratumoral microbes and CAFs mediates the response to nCRT.

Determining the survival benefit of postoperative radiotherapy in patients with pT1-3N1M0 rectal cancer undergoing total mesorectal excision: a retrospective analysis

BACKGROUND

The National Comprehensive Cancer Network guidelines recommend routine postoperative adjuvant radiotherapy and chemotherapy for patients with stage III rectal cancer who do not receive neoadjuvant therapy before surgery. The present study aimed to evaluate the value of postoperative radiotherapy in patients with low-risk disease (pT1-3N1M0) who did not receive neoadjuvant therapy prior to total mesorectal excision.

METHODS

We used the Surveillance, Epidemiology, and End Results database (2004-2016) to retrospectively recruit patients with pT1-3N1M0 rectal cancer whose initial treatment was radical surgery with postoperative adjuvant chemotherapy. A propensity score model was used to balance the baseline covariates.

RESULTS

Of the 2012 patients included in the present study, 1384 received adjuvant chemoradiotherapy (radio group), whereas the remaining 718 received chemotherapy alone (no-radio group). There was no significant difference in cancer-specific survival rate between the two groups (log-rank test χ² = 2.372, P = 0.124) in the overall sample. Additionally, in the propensity score-matched cohort, adjuvant radiotherapy did not improve cancer-specific survival. Subgroup analysis showed that having three positive lymph nodes and a tumor > 50 mm, combined with postoperative adjuvant chemotherapy, could lead to an improved tumor-specific survival rate, while other cases did not benefit from postoperative radiotherapy.

CONCLUSIONS

For patients with pT1-3N1M0 rectal cancer who did not receive neoadjuvant therapy before surgery, postoperative radiotherapy in addition to adjuvant chemotherapy did not significantly improve survival rates. The number of positive nodes (n = 3) and tumor size (> 50 mm) were found to be potential screening indicators for postoperative adjuvant radiotherapy.

Effect of Neoadjuvant Therapy on the Functional Outcome of Patients With Rectal Cancer: A Systematic Review and Meta-Analysis

AIMS

The impact of neoadjuvant therapy on the functional outcome of patients with resectable rectal cancer is still controversial. The aim of the present study was to explore the effects of neoadjuvant therapy on anorectal function (ARF), urinary function and sexual function in relevant patients.

MATERIALS AND METHODS

PubMed, Embase, Web of Science and the Cochrane Library were searched systematically. All English-language studies, published from January 2000 to July 2021, that explored the (postoperative) effects of neoadjuvant therapy versus upfront surgery on ARF, urinary function and sexual function of patients were included (PROSPERO 2021: CRD42021281617).

RESULTS

The data in this study were derived from 37 articles based on 33 studies; in total, 17 917 patients were enrolled. The meta-analysis revealed that the incidence of anorectal dysfunction in the neoadjuvant therapy group was significantly higher than that in the group of upfront surgery, which was manifested by a higher incidence of major low anterior resection syndrome (odds ratio = 3.09, 95% confidence interval = 2.48, 3.84; P < 0.001), reduction of mean squeeze pressure and mean resting pressure, and other manifestations, including clustering of stools, incontinence, urgency and use of pads. With the extension of follow-up time, the adverse effects of neoadjuvant therapy on major low anterior resection syndrome existed. Compared with patients undergoing upfront surgery, neoadjuvant therapy increased the risk of urinary incontinence (odds ratio = 1.31, 95% confidence interval = 1.00, 1.72; P = 0.05) and erectile dysfunction (odds ratio = 1.77, 95% confidence interval = 1.27, 2.45; P < 0.001).

CONCLUSION

Compared with upfront surgery, neoadjuvant therapy is not only associated with impairment of ARF, but also with increased incidence of urinary incontinence and male erectile dysfunction. However, the influence of confounding factors (e.g. surgical method, tumour stage) needs to be considered.

The pattern of bowel dysfunction in patients with rectal cancer following the multimodal treatment: anorectal manometric measurements at before and after chemoradiation therapy, and postoperative 1 year

PURPOSE

Bowel dysfunction commonly occurs in patients with locally advanced rectal cancer treated with a multimodal approach of chemoradiation therapy (CRT) combined with sphincter-preserving rectal resection. This study investigated the decline in anorectal function using sequential anorectal manometric measurements obtained before and after the multimodal treatment as well as at a 1-year follow-up.

METHODS

This was a retrospective cohort study conducted in a single center. The study population consisted of patients with locally advanced mid- to low rectal cancer who received the preoperative CRT followed by sphincter-preserving surgery from 2012 to 2016. The anorectal manometric value measured after each treatment modality was compared to demonstrate the degree of decline in anorectal function. A generalized linear model of repeated measures was performed using the manometric values measured pre- and post-CRT, and at 12 months postoperatively.

RESULTS

Overall, 100 patients with 3 consecutive manometric data were included in the final analysis. In the overall cohort study, the mean resting and maximal squeezing pressures showed insignificant decrement post-neoadjuvant CRT. At a 1-year postoperative follow-up, the maximal squeezing pressure significantly decreased. The maximal rectal sensory threshold demonstrated significant reduction consecutively after each following treatment (P<0.001).

CONCLUSION

The short-term effect of neoadjuvant CRT on the anal sphincters was relatively trivial. The following sphincter-saving surgery resulted in a profound disruption of the anorectal function. Patients with rectal cancer should be consulted on the consequence of multimodal treatment.

Long-term adverse effects and healthcare burden of rectal cancer radiotherapy: systematic review and meta-analysis

BACKGROUND

As rectal cancer survival increases, more patients survive with potentially severe, long-term gastrointestinal and genitourinary complications from radiotherapy. The burden of these complications for patients and healthcare services is unclear, which this review aims to quantify.

METHODS

Systematic search of Medline and Embase for randomized-controlled trials (RCTs) and multicentre observational studies published since 2000, reporting hospitalization/procedural intervention for long-term (>6 months post-treatment) gastrointestinal or genitourinary complications after radiotherapy and surgery for rectal cancer. Prevalence values were pooled in a meta-analysis assuming random effects. Organ-preservation patients were excluded.

RESULTS

4044 records screened; 24 reports from 23 studies included (15 RCTs, 8 Observational), encompassing 15 438 patients. Twenty-one studies (median follow-up 60 months) reported gastrointestinal complications post-radiotherapy: pooled prevalence 11% (95% confidence interval (95% CI) 8-14%). Thirteen reported small bowel obstruction: prevalence 9% (95% CI 6-12%), a 58% increased risk compared with surgery alone (RR 1.58, 95% CI 1.26-1.98, n = 5 studies). Seven reported fistulas: prevalence 1% (95% CI 1-2%). Thirteen reported genitourinary complications: prevalence 4% (95% CI 1-6%); RR 1.10 (95% CI 0.88-1.38, n = 3 studies) compared with surgery alone.

CONCLUSIONS

Over 10% of patients are hospitalized for long-term complications following rectal cancer radiotherapy. Serious gastrointestinal complications are commonplace; late small bowel obstruction is more common in patients having radiotherapy and surgery compared with surgery alone. Patients and clinicians need to be aware of these risks.

Efficacy of neoadjuvant CapeOX/mFOLFOX6 without radiation for patients with baseline resectable mid-low locally advanced rectal cancer

OBJECTIVES

Chemotherapy without radiation therapy for locally advanced rectal cancer (LARC) has attracted increasing attention, but the optimal schema remains controversial. In this study, we aimed to assess the efficacy and toxicity of neoadjuvant chemotherapy (nCT) of two regimens for patients with mid-low baseline resectable LARC.

METHODS

A retrospective study was performed in 131 patients with baseline resectable LARC in a single center between April 2016 and August 2020. All patients received four cycles of neoadjuvant CapeOX or mFOLFOX6 before surgery. Clinical characteristics, pathological response, and survival status were then assessed.

RESULTS

After a 1:1 propensity score matching, 96 patients were enrolled, including 48 receiving CapeOX and 48 receiving mFOLFOX6. The objective regression rates were 50.00% and 58.33%, and the pathological complete response rates were 6.25% and 8.33%, respectively, in the CapeOX and mFOLFOX6 groups. Patients who received mFOLFOX6 had a better tumor regression grade (TRG) than those who received CapeOX (P = 0.005). Patients in both groups had similar survival outcomes.

CONCLUSIONS

The nCT has shown promising tumor response and survival outcomes, which can be a treatment option for baseline resectable LARC. For the two regimens, mFOLFOX6 provided better TRG than CapeOX, although no differences were observed in disease-free survival and OS.

Low anterior resection syndrome following rectal cancer surgery: are incidence and severity lower with long-term follow-up?

BACKGROUND

Low anterior resection syndrome (LARS) is a functional disorder that may follow restorative proctectomy. The aim of this study was to evaluate the long-term incidence and risk factors for LARS following surgery for rectal cancer.

METHODS

A retrospective study was performed on patients from a prospectively maintained database, who underwent a restorative proctectomy between January 2014 and December 2019 at Hadassah Hebrew University Medical Center. The study cohort was divided into two groups: patients following partial proctectomy with a partial mesorectal excision and a colorectal anastomosis (PME group) and patients following total proctectomy with total mesorectal excision and a coloanal anastomosis (TME group). The incidence and severity of LARS were evaluated using the LARS questionnaire. Risk factors for LARS were also evaluated.

RESULTS

A total of 240 patients (male: female ratio 134:106, median age 64 years [interquartile range 55-71 years]) were included in the analysis. There were 160 patients in the PME group and 80 patients in the TME group. The overall incidence of LARS was 37.4% (26.5% major LARS and 10.9% minor LARS). Major LARS was observed in 53.8% of patients who underwent TME and in 12.7% of patients who underwent PME (p < 0.001). On multivariate analysis, distance of the anastomosis from the anal verge, TME, and neoadjuvant radiotherapy were independent prognostic factors for LARS. The incidence and severity of LARS were significantly lower in patients with longer follow-up (p = 0.05).

CONCLUSIONS

Significant improvement in LARS can be expected with longer follow-up. Distance of the anastomosis from the anal verge, TME and neoadjuvant radiotherapy are independent risk factors for LARS.

Ionizing Radiation from Radiopharmaceuticals and the Human Gut Microbiota: An Ex Vivo Approach

This study aimed to determine the effect of three widely used radiopharmaceuticals with intestinal excretion on selected relevant bacteria that are part of the human gut microbiota, using an ex vivo approach. Fecal samples obtained from healthy volunteers were analyzed. Each sample was divided into four smaller aliquots. One served as the non-irradiated control. The other three were homogenized with three radiopharmaceutical solutions ([¹³¹I]NaI, [^99mTc]NaTcO₄, and [²²³Ra]RaCl₂). Relative quantification of each taxa was determined by the 2^−ΔΔC method, using the ribosomal gene 16S as an internal control (primers 534/385). Twelve fecal samples were analysed: three controls and nine irradiated. Our experiment showed fold changes in all analyzed taxa with all radiopharmaceuticals, but results were more significant with I-131, ranging from 1.87–83.58; whereas no relevant differences were found with Tc-99m and Ra-223, ranging from 0.98–1.58 and 0.83–1.97, respectively. This study corroborates limited existing research on how ionizing radiation changes the gut microbiota composition, providing novel data regarding the ex vivo effect of radiopharmaceuticals. Our findings justify the need for future larger scale projects.

An assessment of left-digit bias in the treatment of older patients with potentially curable rectal cancer

BACKGROUND

Patient age is associated with poorer rectal cancer treatment compliance. However, it is unknown whether left-digit bias (disproportionate influence of leftmost age digit) influences this association.

METHODS

The patients diagnosed with stage I-III rectal cancer between 2006 to 2017 in the National Cancer Database were identified. The association between age and receipt of guideline-adherent care was assessed using mixed-effects multivariable analyses.

RESULTS

Among 97,960 patients, 46.2% received guideline-adherent overall treatment and 73.3% underwent guideline-adherent surgical resection. Of those who underwent guideline-adherent surgery, 86.4% received guideline-adherent radiotherapy and 56.6% received guideline-adherent chemotherapy. After risk-adjustment, each decade increase in age was associated with 36% decreased odds of guideline-adherent therapy (odds ratio = 0.64, 95% confidence interval = 0.63-0.65). Patients aged 58 to 59 (odds ratio = 1.15, 95% confidence interval = 1.02-1.27) and 78 to 79 (odds ratio = 1.28, 95% confidence interval = 1.08-1.51) had higher odds of guideline-adherent overall treatment compared with patients aged 60 and 80, respectively. However, there were no significant differences in the receipt of guideline-adherent treatment between patients aged 60 vs 61-62 and 80 vs 81-82.

CONCLUSION

Older patients with rectal cancer are less likely to receive guideline-adherent care, and a left-digit bias is present. Geriatric assessment-guided treatment decisions could help mitigate this bias.

The Longitudinal Course of Low-anterior Resection Syndrome: An individual Patient Meta-analysis

OBJECTIVE

We aimed to better understand the longitudinal course of low anterior resection syndrome (LARS) to guide patient expectations and identify those at risk of persisting dysfunction.

SUMMARY BACKGROUND DATA

LARS describes disordered bowel function after rectal resection that significantly impacts quality of life.

METHODS

MEDLINE, EMBASE, CENTRAL, and CINAHL databases were systematically searched for studies that enrolled adults undergoing anterior resection for rectal cancer and used the LARS score to assess bowel function at ≥2 postoperative time points. Regression analyses were performed on deidentified patient-level data to identify predictors of change in LARS score from baseline (3-6months) to 12-months and 18-24 months.

RESULTS

Eight studies with a total of 701 eligible patients were included. The mean LARS score improved over time, from 29.4 (95% confidence interval 28.6-30.1) at baseline to 16.6 at 36 months (95% confidence interval 14.2%-18.9%). On multivariable analysis, a greater improvement in mean LARS score between baseline and 12 months was associated with no ileostomy formation [mean difference (MD) -1.7 vs 1.7, P < 0.001], and presence of LARS (major vs minor vs no LARS) at baseline (MD -3.8 vs -1.7 vs 5.4, P < 0.001). Greater improvement in mean LARS score between baseline and 18-24 months was associated with partial mesorectal excision vs total mesorectal excision (MD-8.6 vs 1.5, P < 0.001) and presence of LARS (major vs minor vs no LARS) at baseline (MD -8.8 vs -5.3 vs 3.4, P < 0.001).

CONCLUSIONS

LARS improves by 18 months postoperatively then remains stable for up to 3 years. Total mesorectal excision, neoadjuvant radiotherapy, and ileostomy formation negatively impact upon bowel function recovery.

Are We There Yet? The Value of Deep Learning in a Multicenter Setting for Response Prediction of Locally Advanced Rectal Cancer to Neoadjuvant Chemoradiotherapy

This retrospective study aims to evaluate the generalizability of a promising state-of-the-art multitask deep learning (DL) model for predicting the response of locally advanced rectal cancer (LARC) to neoadjuvant chemoradiotherapy (nCRT) using a multicenter dataset. To this end, we retrained and validated a Siamese network with two U-Nets joined at multiple layers using pre- and post-therapeutic T2-weighted (T2w), diffusion-weighted (DW) images and apparent diffusion coefficient (ADC) maps of 83 LARC patients acquired under study conditions at four different medical centers. To assess the predictive performance of the model, the trained network was then applied to an external clinical routine dataset of 46 LARC patients imaged without study conditions. The training and test datasets differed significantly in terms of their composition, e.g., T-/N-staging, the time interval between initial staging/nCRT/re-staging and surgery, as well as with respect to acquisition parameters, such as resolution, echo/repetition time, flip angle and field strength. We found that even after dedicated data pre-processing, the predictive performance dropped significantly in this multicenter setting compared to a previously published single- or two-center setting. Testing the network on the external clinical routine dataset yielded an area under the receiver operating characteristic curve of 0.54 (95% confidence interval [CI]: 0.41, 0.65), when using only pre- and post-therapeutic T2w images as input, and 0.60 (95% CI: 0.48, 0.71), when using the combination of pre- and post-therapeutic T2w, DW images, and ADC maps as input. Our study highlights the importance of data quality and harmonization in clinical trials using machine learning. Only in a joint, cross-center effort, involving a multidisciplinary team can we generate large enough curated and annotated datasets and develop the necessary pre-processing pipelines for data harmonization to successfully apply DL models clinically.

Short-term outcomes of neoadjuvant chemotherapy with capecitabineplus oxaliplatin for patients with locally advanced rectal cancerfollowed by total or tumor-specific mesorectal excision with orwithout lateral pelvic lymph node dissection

Background: The standard strategy in Japan for locally advanced rectal cancer is total mesorectal excision plus adjuvant chemotherapy. However, large tumors significantly restrict pelvic manipulation of the distal side of the tumor during surgery; therefore, from an oncological point of view, it is better to shrink the tumor as much as possible preoperatively to optimize the circumferential resection margin. In recent years, advances in systemic chemotherapy have significantly improved the tumor reduction effect, enabling such drug therapy prior to surgery for locally advanced rectal cancer. We herein retrospectively evaluated the clinical, short-term outcomes of patients treated by neoadjuvant chemotherapy (NAC) using capecitabin and oxaliplatin (CAPOX), focusing on overall safety as well as clinical and pathological staging responses to NAC.

Methods: We applied the preoperative chemotherapy protocol to T3-4, any N, M0 or M1a (with resectable metastases) (UICC 8^th) Ra/Rb rectal cancers. The chemotherapy regimen consisted of four cycles of CAPOX. After NAC, curative intent surgery with total mesorectal excision/tumor-specific mesorectal excision with/without metastasectomy was performed. Adverse effects (AEs) and compliance with NAC, surgical complications, clinical and pathological staging were evaluated. All patients undergoing the protocol between January 2017 and June 2021 at Fukushima Medical University were enrolled.

Results: Twenty cases were enrolled. No severe AEs were observed either preoperatively or perioperatively. Preoperative assessment of NAC showed no cases of progressive disease (PD). Radical resection was achieved in all cases. Histological therapeutic grading after NAC revealed one grade 3, four grade 2, three grade 1b, eleven grade 1a and one grade 0 among all cases.

Conclusion: This study suggests that NAC for locally advanced rectal cancer is likely to be acceptable because there were no severe AEs pre- or perioperatively, radical resection was achieved in all cases, and there were no cases of PD.

Robotic surgery contributes to the preservation of bowel and urinary function after total mesorectal excision: comparisons with transanal and conventional laparoscopic surgery

BACKGROUND

Determine whether robotic surgery is more effective than transanal and conventional laparoscopic surgery in preserving bowel and urinary function after total mesorectal excision (TME).

METHODS

Of 79 lower rectal cancer patients who underwent function-preserving TME between 2016 and 2020, 64 patients consented to a prospective questionnaire-based functional observation study (52 responded). At 6 months post-resection or ileostomy closure, Wexner, low anterior resection syndrome (LARS), modified fecal incontinence quality of life, and international prostate symptom scores were used to evaluate bowel and urinary function, comparing robotic surgery (RTME) with transanal (taTME) or conventional laparoscopic surgery (LTME).

RESULTS

RTME was performed in 35 patients (54.7%), taTME in 15 (23.4%), and LTME in 14 (21.9%). While preoperative bowel/urinary functions were similar in all three procedures, and the distance from the anal verge to tumor was almost the same, more hand-sewn anastomoses were performed and the anastomotic height from the anal verge was shorter in taTME than RTME. At 2 years post-resection, 8 patients (12.5%) had a permanent stoma; RTME showed a significantly lower rate of permanent stoma than taTME (2.9% vs. 40%, p < 0.01). Despite no significant difference, all bowel function assessments were better in RTME than in taTME or LTME. Major LARS was observed in all taTME and LTME cases, but only 78.8% of RTME. No clear difference arose between RTME and taTME in urinary function; urinary dysfunction was more severe in LTME than RTME (36.4% vs. 6.1%, p = 0.02).

CONCLUSIONS

In function-preserving TME for lower rectal cancer, robotic surgery was suggested to be more effective than transanal and conventional laparoscopic surgery in terms of bowel and urinary functions.

Predicting response to neoadjuvant chemoradiotherapy in rectal cancer: from biomarkers to tumor models

Colorectal cancer (CRC) is a major contributor to cancer-associated morbidity worldwide and over one-third of CRC is located in the rectum. Neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection is commonly applied to treat locally advanced rectal cancer (LARC). In this review, we summarize current and novel concepts of neoadjuvant therapy for LARC such as total neoadjuvant therapy and describe how these developments impact treatment response. Moreover, as response to nCRT is highly divergent in rectal cancers, we discuss the role of potential predictive biomarkers. We review recent advances in biomarker discovery, from a clinical as well as a histopathological and molecular perspective. Furthermore, the role of emerging predictive biomarkers derived from the tumor environment such as immune cell composition and gut microbiome is presented. Finally, we describe how different tumor models such as patient-derived cancer organoids are used to identify novel predictive biomarkers for chemoradiotherapy (CRT) in rectal cancer.

Neoadjuvant Chemotherapy plus Bevacizumab Combined with Total Mesorectal Excision in Treating Locally Advanced Rectal Cancer Patients with BRAF Mutation: Clinical Benefit and Safety

Objective

To investigate clinical benefit and safety of neoadjuvant chemotherapy (NAC) plus bevacizumab combined with total mesorectal excision (TME) in treating patients with BRAF-mutated locally advanced rectal cancer (LARC).

Methods

This study included LARC patients with BRAF mutation admitted to the Oncology Department of Fujian Medical University Cancer Hospital, Fujian Cancer Hospital, between June 2013 and December 2018. Patients in the control group received a standard treatment regimen of TME combined with NAC (n = 45), and patients in the observation group received NAC plus bevacizumab combined with TME (n = 55). The short-term clinical efficacy of the two groups after NAC treatment was observed and compared, including differences in the pathological downstaging rate. The incidence of perioperative complications and adverse reactions during neoadjuvant therapy was compared to evaluate the safety of the treatment. Besides, the relapse-free survival (RFS) and overall survival (OS) of patients were analyzed to evaluate the long-term clinical benefit of the treatment.

Results

Compared with the control group, the ypT staging rate (p = 0.014) in the observation group was markedly lower. In addition, patients in the observation group had a prominently lower overall incidence of complications (p < 0.001) during the perioperative period and a remarkably lower incidence of leukopenia (p = 0.037) during neoadjuvant therapy. In terms of long-term clinical benefit, the RFS of patients in the observation group was evidently longer (p = 0.037) than that in the control group.

Conclusion

Compared with TME plus NAC treatment, the short-term and long-term clinical benefits are higher and safety is more favorable of NAC plus bevacizumab combined with TME in treating LARC patients.

Re-evaluation of controversial issues in the treatment of cT3N0-2 rectal cancer: a 10-year cohort analysis using propensity-score matching

BACKGROUND

Although neoadjuvant treatment is thought to provide optimal local control for stage II and III rectal cancers, many patients have been reported cured by total mesorectal excision (TME), alone or with additional chemotherapy (CTX).

METHODS

This study retrospectively evaluated outcomes in 2643 patients with cT3N0-2 rectal cancers undergoing curative TME during 2005-2015. Recurrence and survival outcomes were measured in three propensity-score matched groups, consisting of patients who underwent preoperative chemoradiotherapy (CRT) with postoperative CTX (NAPOC), postoperative CRT (POCRT), and exclusively postoperative CTX (EPOCT).

RESULTS

Near-complete or complete TME was conducted in more than 95.9% of patients and 80% of scheduled dose of postoperative CTX was completed in 99%. Except for higher SR rate in the POCRT group than the NAPOC group (p = 0.008), 5-year cumulative local and systemic recurrence (LR and SR) rates were 4.9% and 15.2% for cT3N0, and 4.2% and 21% for cT3N1-2 patients (LR, p = 0.703; SR, 0.065), respectively, with no significant differences associated with treatment exposure (p = 0.11-1). The 5-year cumulative disease-free (75.6% vs 65.7%, p = 0.018) and overall survival (87.1% vs 79.4%, p = 0.018 each) rates were higher in the NAPOC group than the POCRT group with cT3N1-2. However, any significant survival differences were not identified between the NAPOC and EPOCT groups according to tumor sub-stages or locations (p = 0.395-0.971).

CONCLUSIONS

We found any treatment modalities including competent TME and postoperative adjuvant CTX efficiently reducing LR generating robust survival outcome in the propensity-matched cohorts, demanding further randomized controlled trials by clinical sub-stages II-III.

Assessment of defecation function after sphincter-saving resection for mid to low rectal cancer: A cross-sectional study

PURPOSE

Patients with mid-to low-rectal cancer can have various dysfunctions of defecation after sphincter-saving resection. Defecation dysfunction can manifest as incontinence, urgency, or frequent bowel movements, and is called low anterior resection syndrome (LARS). This study aimed to examine LARS score and objective anorectal function indices in Chinese patients receiving sphincter-saving surgery for mid-to low-rectal cancer.

METHOD

This was a single-center cross-sectional study of patients undergoing sphincter-saving resection for low- or mid-rectal cancer and had restoration of trans-anal defecation for at least 1 month seen between January 2019 and June 2020. Patients completed a questionnaire regarding clinical characteristics, and Low Anterior Resection Syndrome (LARS) score and high-resolution anorectal manometry (HR-ARM) were used to assess defecation function. Multivariable analysis was used to identify variables significantly associated with defecation dysfunction.

RESULTS

146 patients completed and returned the questionnaires. 25 healthy adults also participated as control group for the anorectal manometry. Approximately 76% of patients developed LARS after surgery, of which 35.6% had major LARS. In these patients, anorectal manometry indices including initial rectal sensory capacity and rectal fecal sensory capacity, were significantly lower than normal. Logistic regression analysis showed that preoperative chemo-radiotherapy and the tumor inferior margins being close to the dentate line, especially 2-5 cm, were independent risk factors for defecation dysfunction after surgery.

CONCLUSIONS

Defecation dysfunction is a frequent occurrence after sphincter-saving resection for mid- and low-rectal cancer. Preoperative chemo-radiotherapy and a shorter tumor inferior margins distance to the dentate line are independent factors for defecation dysfunction.

Burden of disease experienced by patients following a watch-and-wait policy for locally advanced rectal cancer: A qualitative study

AIM

Patient-reported outcome measures (PROMs) are increasingly being used in routine cancer care to evaluate treatment and monitor symptoms, function and other aspects of quality of life (QoL). There is no suitable PROM for rectal cancer patients following a watch-and-wait (W&W) programme. Insight into patient experiences with this programme is an essential step in the development of a PROM. The aim of this qualitative study was to provide insights into the most important functional outcomes and QoL features experienced by patients during our W&W programme.

METHOD

Patients with locally advanced rectal cancer who are enrolled in the W&W programme in the Netherlands were interviewed by telephone using a semistructured interview guide. All interviews were digitally audio-recorded, transcribed verbatim and coded. A thematic approach was used to analyse the data and identify themes and subthemes of importance to patients.

RESULTS

Eighteen patients were interviewed (78% male, mean age 68 years, range 52-83 years). Physical complaints after treatment were present, most notably gastrointestinal problems, neuropathy and fatigue. Furthermore, patients were anxious about a possible recurrence, had a fear of surgery or a stoma, or were experiencing a general feeling of apprehension in daily life. Many patients had different coping mechanisms, such as acceptance, and there were few limitations in daily life.

CONCLUSION

We identified important functional outcomes, such as gastrointestinal complaints, fatigue and neuropathy, in patients who were enrolled in this W&W programme. Furthermore, an emotional burden and unmet needs were reported by these patients. These findings can be used to improve clinical practice and inform the development of a PROM.

CD133 Expression Predicts Relapse in Patients With Locally Advanced Rectal Cancer Treated With Neoadjuvant Chemotherapy

AIM

The aim of the present study was to explore the association between CD133 expression and postoperative relapses in patients with locally advanced rectal cancer (LARC) who received neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

We retrospectively examined 52 patients with LARC (cT3-4, Nany, M0) who received oxaliplatin-based NAC before surgery. CD133 expression was evaluated using immunohistochemistry and divided into low and high expression groups.

RESULTS

High CD133 expression was observed in 22 patients (42.3%). Patients with high CD133 expression had more frequent vessel invasion and relapse than those with low CD133 expression (p=0.013 and p=0.036, respectively). Comparing the low with high CD133 expression groups, the 4-year relapse-free survival rates were 82.2% vs. 46.3% (p=0.009). Multivariate analysis indicated that CD133 expression was an independent risk factor for relapse (HR=3.138; 95%CI=1.046-9.412; p=0.041).

CONCLUSION

CD133 expression may be a predictive biomarker for postoperative relapse in patients with LARC who received NAC before surgery.

The transverse coloplasty pouch is technically easy and safe and improves functional outcomes after low rectal cancer resection-a single center experience with 397 patients

BACKGROUND

Following resection for low rectal cancer, numerous patients suffer from frequent bowel movements, fecal urgency, and incontinence. Although there is good evidence that colonic J-pouch reconstruction, side-to-end anastomosis, or a transverse coloplasty pouch (TCP) improves functional outcome, many surgeons still prefer straight coloanal anastomosis because it is technically easier and lacks the risk of pouch-associated complications. The present single-center study aimed to evaluate the practicability of TCPs in routine clinical practice as well as pouch-related complications.

METHOD

All consecutive patients who underwent low anterior rectal resection with restoration of bowel continuity for cancer during the period September 2008 to June 2018 were included. A TCP in combination with a diverting ileostomy was defined as the hospital standard. The feasibility and safety of TCPs were assessed in a retrospective single-center study.

RESULTS

A total of 397 patients were included in the study. A total of 328/397 patients underwent TCP construction (82.6%). Two pouch-related surgical complications occurred (0.6%); one case of pouch-related stenosis and one case of sutural insufficiency. Overall, leakage of the coloanal anastomosis was reported in 14.1% of patients with a TCP and in 18.8% of patients without a pouch (p=0.252). Diverting ileostomy was applied in 378/397 patients (95.2%). The 30-day mortality was 0.25%.

CONCLUSION

The present study is by far the largest single-center experience with TCP construction for low rectal cancer resection. The study shows that a TCP is technically applicable in the vast majority of cases (82.6%). Pouch-associated surgical complications are sporadic events. In our opinion, the TCP can be considered an alternative to J-pouch construction after low anterior rectal resection.

Urinary dysfunction after colorectal cancer treatment and its impact on quality of life - a national cross-sectional study in women

AIM

The aim of this study was to investigate urinary dysfunction and its impact on the quality of life of colorectal cancer survivors. We also wanted to identify the risk factors for impaired urinary function.

METHOD

A national cross-sectional study was performed including patients treated for colorectal cancer between 2001 and 2014. Patients answered questionnaires regarding urinary function and quality of life, including the International Consultation on Incontinence Questionnaire - Female Lower Urinary Tract Symptoms (ICIQ-FLUTS), measuring filling, voiding and incontinence. Data were compared with data on demographics and treatment-related factors from the Danish Colorectal Cancer Group (DCCG) database.

RESULTS

We found that rectal cancer treatment significantly impaired urinary function compared with colon cancer treatment (filling score p = 0.003, voiding p < 0.0001, incontinence p = 0.0001). Radiotherapy was the single most influential risk factor for high filling (p = 0.0043), voiding (p < 0.0001) and incontinence (p < 0.0001) scores, whereas type of rectal resection was only significant in crude analysis. Urinary dysfunction was strongly associated with an impaired quality of life.

CONCLUSION

Urinary dysfunction is common after treatment for colorectal cancer, particularly if the treatment includes radiotherapy. All patients must be informed of the risk before cancer treatment, and functional outcome should be routinely assessed at follow-up.

Role of Preoperative Chemoradiotherapy in Clinical Stage II/III Rectal Cancer Patients Undergoing Total Mesorectal Excision: A Retrospective Propensity Score Analysis

Background

Although the current standard preoperative chemoradiotherapy (PCRT) for stage II/III rectal cancer decreases the risk of local recurrence, it does not improve survival and increases the likelihood of preoperative overtreatment, especially in patients without circumferential resection margin (CRM) involvement.

Methods

Stage II/III rectal cancer without CRM involvement and lateral lymph node metastasis was radiologically defined by preoperative magnetic resonance imaging (MRI). Patients who received PCRT followed by total mesorectal excision (TME) (PCRT group) and upfront surgery (US) with TME (US group) between 2010 and 2016 were analyzed. We derived cohorts of PCRT group versus US group using propensity-score matching for stage, age, and distance from the anal verge. Three-year relapse-free survival rate, disease-free survival (DFS), and overall survival (OS) were compared between the two groups.

Results

A total of 202 patients were analyzed after propensity score matching. There were no differences in baseline characteristics. The median follow-up duration was 62 months (interquartile range, 46–87). There was no difference in the 3-year disease-free survival rate between the PCRT and US groups (83 vs. 88%, respectively; p=0.326). Likewise, there was no significant difference in the 3-year OS (89 vs. 91%, respectively; p=0.466). The 3-year locoregional recurrence rates (3 vs. 2% with US, p=0.667) and distant metastasis rates (16 vs. 11%, p=0.428) were not significantly different between the two groups. Time to completion of curative treatment was significantly shorter in the US group (132 days) than in the PCRT group (225 days) (p<0.001).

Conclusion

Using MRI-guided selection for better risk stratification, US without neoadjuvant therapy can be considered in early stage patients with good prognosis. PCRT may not be required for all stage II/III rectal cancer patients, especially for the MRI-proven intermediate-risk group (cT1-2/N1, cT3N0) without CRM involvement and lateral lymph node metastasis. Further prospective studies are warranted.

Functional outcomes of surgery for colon cancer: A systematic review and meta-analysis

INTRODUCTION

As survival rates of colon cancer increase, knowledge about functional outcomes is becoming ever more important. The primary aim of this systematic review and meta-analysis was to quantify functional outcomes after surgery for colon cancer. Secondly, we aimed to determine the effect of time to follow-up and type of colectomy on postoperative functional outcomes.

MATERIALS AND METHODS

A systematic literature search was performed to identify studies reporting bowel function following surgery for colon cancer. Outcome parameters were bowel function scores and/or prevalence of bowel symptoms. Additionally, the effect of time to follow-up and type of resection was analyzed.

RESULTS

In total 26 studies were included, describing bowel function between 3 to 178 months following right hemicolectomy (n = 4207), left hemicolectomy/sigmoid colon resection (n = 4211), and subtotal/total colectomy (n = 161). In 16 studies (61.5%) a bowel function score was used. Pooled prevalence for liquid and solid stool incontinence was 24.1% and 6.9%, respectively. The most prevalent constipation-associated symptoms were incomplete evacuation and obstructive, difficult emptying (33.3% and 31.4%, respectively). Major Low Anterior Resection Syndrome was present in 21.1%. No differences between time to follow-up or type of colectomy were found.

CONCLUSION

Bowel function problems following surgery for colon cancer are common, show no improvement over time and do not depend on the type of colectomy. Apart from fecal incontinence, constipation-associated symptoms are also highly prevalent. Therefore, more attention should be paid to all possible aspects of bowel dysfunction following surgery for colon cancer and targeted treatment should commence promptly.

Nonoperative Management for T2 Low Rectal Cancer: A Western Approach

The possibility of organ preservation in early rectal cancer has gained popularity during recent years. Patients with early tumor stage and low risk for local recurrence do not usually require neoadjuvant chemoradiation for oncological reasons. However, these patients may be considered for chemoradiation exclusively for the purpose of achieving a complete clinical response and avoid total mesorectal excision. In addition, cT2 tumors may be more likely to develop complete response to neoadjuvant therapy and may constitute ideal candidates for organ-preserving strategies. In the setting where the use of chemoradiation is exclusively used to avoid major surgery, one should consider maximizing tumor response. In this article, we will focus on the rationale, indications, and outcomes of patients with early rectal cancer being treated by neoadjuvant chemoradiation to achieve organ preservation by avoiding total mesorectal excision.

Pre-Treatment T2-WI Based Radiomics Features for Prediction of Locally Advanced Rectal Cancer Non-Response to Neoadjuvant Chemoradiotherapy: A Preliminary Study

Locally advanced rectal cancer (LARC) response to neoadjuvant chemoradiotherapy (nCRT) is very heterogeneous and up to 30% of patients are considered non-responders, presenting no tumor regression after nCRT. This study aimed to determine the ability of pre-treatment T2-weighted based radiomics features to predict LARC non-responders. A total of 67 LARC patients who underwent a pre-treatment MRI followed by nCRT and total mesorectal excision were assigned into training (n = 44) and validation (n = 23) groups. In both datasets, the patients were categorized according to the Ryan tumor regression grade (TRG) system into non-responders (TRG = 3) and responders (TRG 1 and 2). We extracted 960 radiomic features/patient from pre-treatment T2-weighted images. After a three-step feature selection process, including LASSO regression analysis, we built a radiomics score with seven radiomics features. This score was significantly higher among non-responders in both training and validation sets (p < 0.001 and p = 0.03) and it showed good predictive performance for LARC non-response, achieving an area under the curve (AUC) = 0.94 (95% CI: 0.82–0.99) in the training set and AUC = 0.80 (95% CI: 0.58–0.94) in the validation group. The multivariate analysis identified the radiomics score as an independent predictor for the tumor non-response (OR = 6.52, 95% CI: 1.87–22.72). Our results indicate that MRI radiomics features could be considered as potential imaging biomarkers for early prediction of LARC non-response to neoadjuvant treatment.

Upfront radical surgery with total mesorectal excision followed by adjuvant FOLFOX chemotherapy for locally advanced rectal cancer (TME-FOLFOX): an open-label, multicenter, phase II randomized controlled trial

Background

Preoperative chemoradiotherapy (PCRT) followed by surgery and adjuvant chemotherapy is the current standard treatment for stage II/III rectal cancer. However, radiotherapy in the pelvic area is commonly associated with complications such as anastomotic leakage, sexual dysfunction, and fecal incontinence. Recently, the MERCURY study showed that preoperative high-resolution magnetic resonance imaging (MRI) helped to selectively avoid PCRT. It remains unclear whether PCRT is necessary in patients who can achieve a negative circumferential resection margin (CRM) with surgery alone and in patients with cT_1–2N₁ or cT₃N₀ without CRM involvement and lateral lymph node metastasis. This study aims to evaluate the efficacy of upfront radical surgery with total mesorectal excision (TME) followed by adjuvant chemotherapy with folinic acid (or leucovorin), fluorouracil, and oxaliplatin (FOLFOX) versus the current standard treatment in patients with surgically resectable, locally advanced rectal cancer.

Methods

This study, named TME-FOLFOX, is a prospective, open-label, multicenter, phase II randomized trial. Patients with locally advanced rectal cancer will be randomized to receive PCRT followed by TME and adjuvant chemotherapy (arm A) or upfront radical surgery with TME followed by adjuvant FOLFOX chemotherapy (arm B). Clinical stage II/III rectal cancer without CRM involvement and lateral lymph node metastasis will be defined using preoperative MRI. The primary endpoint is 3-year disease-free survival (DFS). Secondary endpoints include 5-year DFS, local recurrence rate, systemic recurrence rate, cost-effectiveness, and overall survival. We hypothesized that our experimental group (arm B) will have a 3-year DFS of 75% and a non-inferiority margin of 15%.

Discussion

Identifying whether patients require PCRT is one of the critical issues in locally advanced rectal cancer. This study aims to elucidate whether PCRT may not be required for all patients with stage II/III rectal cancer, especially for the MRI-based intermediate-risk group (with cT_1–2N₁ or cT₃N₀) without CRM involvement and lateral lymph node metastasis. If the findings indicate that our proposed treatment, which omits PCRT, is non-inferior to the standard treatment, then patients may avoid unnecessary radiation-related toxicity, have a shorter treatment duration, and save on medical costs.

Trial registration

ClinicalTrials.gov, NCT02167321. Registered on 19 June 2014.

Prediction of Poor Response to Neoadjuvant Chemoradiation in Patients With Rectal Cancer Using a DNA Repair Deregulation Score: Picking the Losers Instead of the Winners

BACKGROUND

Patients with rectal cancer may undergo neoadjuvant chemoradiation even in early stages in an attempt to achieve complete clinical response and undergo organ preservation. However, prediction of tumor response is unavailable. In this setting, accurate identification of poor responders could spare patients with early stage disease from potentially unnecessary chemoradiation.

OBJECTIVE

This study focused on development/test of a score based on DNA repair gene expression to predict response to neoadjuvant chemoradiation in patients with rectal cancer.

DESIGN

Pretreatment biopsy samples from patients with rectal cancer undergoing neoadjuvant chemoradiation were collected and underwent gene expression analysis using RNA-Seq (test cohort). A score was constructed using 8 differentially expressed DNA repair genes between good (complete clinical) and poor responders (incomplete clinical) to treatment. The score was validated in 2 independent cohorts of patients undergoing similar treatment strategies and using quantitative polymerase chain reaction and microarray gene expression data.

SETTINGS

This was a retrospective analysis of gene expression data from 3 independent institutions.

PATIENTS

Patients with rectal cancer undergoing neoadjuvant chemoradiation (50.4-54.0 Gy and 5-fluorouracil-based chemotherapy) were eligible. Patients with complete clinical response, complete pathological response, or ≤10% residual cancer cells were considered good responders. Patients with >10% residual cancer cells were considered poor responders. The test cohort included 25 patients (16 poor responders). Validation cohort 1 included 28 patients (18 poor responders), and validation cohort 2 included 46 patients (22 poor responders).

MAIN OUTCOMES MEASURES

Response was correlated with the DNA repair score calculated using the expression levels of 8 DNA repair genes. DNA repair score sensitivity, specificity, and positive and negative predictive values were determined in test and validation cohorts.

RESULTS

Poor responders had significantly lower DNA repair scores when compared with good responders across all 3 cohorts, regardless of the gene expression platform used. A low score correctly predicted poor response in 93%, 90%, and 71% in test, validation 1, and validation 2 cohorts.

LIMITATIONS

This study was limited by its small sample size, different gene expression platforms, and treatment regimens across different cohorts used.

CONCLUSIONS

A DNA repair gene score may predict patients likely to have poor response to chemoradiation. This score may be a relevant tool to be investigated in future studies focused on chemoradiation used in the context of organ preservation. See Video Abstract at http://links.lww.com/DCR/B104. PREDICCIÓN DE RESPUESTA DEFICIENTE A LA RADIO-QUIMIOTERAPIA NEOADYUVANTE EN PACIENTES CON CÁNCER RECTAL UTILIZANDO UNA PUNTUACIÓN DE DESREGULACIÓN DE REPARACIÓN DE ADN: ESCOGER LOS PERDEDORES EN LUGAR DE LOS GANADORES: Los pacientes con cáncer rectal pueden someterse a radio-quimioterapia neoadyuvante incluso en estadios tempranos en el intento por lograr una respuesta clínica completa y permitir una preservación de órgano. Sin embargo, aun no existen herramientas disponible para la prediccion de la respuesta tumoral al tratamiento. En este contexto, la identificación precisa de los tumores con mala respuesta al tratamiento podría evitar que los pacientes con enfermedad en estadio temprano sean sometidos a radio-quimioterapia potencialmente innecesaria.Desarrollo / testeo de una puntuación basada en la expresión genes reparadores del ADN para predecir la respuesta a la nCRT en pacientes con cáncer rectal.Se recogieron muestras de biopsia de pre-tratamiento de pacientes con cáncer rectal sometidos a radio-quimioterapia neoadyuvante y se les realizó un análisis de expresión génica utilizando RNAseq (cohorte de prueba). Se construyó una puntuación utilizando 8 genes de reparación de ADN expresados diferencialmente entre buenos (respuesta clinica completa) y pobres respondedores (respuesta clinica incompleta) al tratamiento. La puntuación se validó en 2 cohortes independientes de pacientes sometidos a estrategias de tratamiento similares y utilizando qPCR y datos de expresión de genes en chips ADN (biotecnología -microarrays).Análisis retrospectivo de los datos de expresión génica de 3 instituciones independientes.Fueron incluidos aquellos pacientes con cáncer rectal sometidos a radio-quimioterapia neoadyuvante (50,4-54 Gy y quimioterapia basada en 5FU). Los pacientes con respuesta clínica completa, respuesta patológica completa o ≤10% de células cancerosas residuales se consideraron buenos respondedores. Los pacientes con> 10% de células cancerosas residuales se consideraron de respuesta deficiente. La cohorte de prueba incluyó a 25 pacientes (16 respondedores pobres). La cohorte de validación n. ° 1 incluyó a 28 pacientes (18 respondedores pobres) y la cohorte de validación n. ° 2 incluyó a 46 pacientes (22 respondedores pobres).La respuesta se correlacionó con la puntuación de reparación de ADN calculada utilizando los niveles de expresión de 8 genes de reparación de ADN. La sensibilidad del puntaje de reparación del ADN, la especificidad, los valores predictivos positivos y negativos se determinaron en las cohortes de prueba y validación.Los malos respondedores tuvieron puntuaciones de reparación de ADN significativamente más bajas en comparación con los buenos respondedores en las 3 cohortes, independientemente de la plataforma de expresión génica utilizada. Una puntuación baja predijo correctamente una respuesta pobre en el 93%, 90% y 71% en las cohortes de prueba, validación n. ° 1 y validación n. ° 2, respectivamente.Pequeño tamaño de la muestra, diferentes plataformas de expresión génica y regímenes de tratamiento en diferentes cohortes utilizadas.La puntuacion basada en genes de reparación del ADN puede predecir los pacientes con respuesta pobre a la radio-quimioterapia. Esta puntuación puede ser una herramienta relevante para investigar en futuros estudios centrados en la radio-quimioterapia utilizada en el contexto de la preservación de órganos. Consulte Video Resumen en http://links.lww.com/DCR/B104. (Traducción-Dr. Xavier Delgadillo and Dr. Laura Melina Fernandez).

Is my life going to change?-a review of quality of life after rectal resection

Rectal resection is a common practice for colorectal surgeons. The causes of this procedure are varied. The most frequent is cancer, but also inflammatory bowel disease, endometriosis, and rectovaginal or rectourethral fistulas. The loss of the normal rectal reservoir function, urinary problems, sexual dysfunction or pelvic pain are frequently reported in patients after rectal surgery and these disorders markedly affect the overall quality of life (QoL). In the last decades, rectal surgery has radically changed, with the development of surgical techniques, and it has progressed from abdominoperineal resection (APR) with a permanent colostomy to sphincter-saving procedures. Nowadays, the use of sphincter-preserving surgery has increased, but all these surgical techniques can have important sequels that modify the QoL of the patients. Historically, surgical outcomes, such as complications, survival and recurrences, have been widely studied by surgeons. In the present day, surgical outcomes have improved, rectal cancer recurrence rate has decreased and survival has increased. For these reasons, it has begun to gain importance in aspects of the QoL of patients, such as body image, fecal continence and sexuality or urinary function. Therefore, physicians should know the influence of different techniques and approaches on functional outcomes and QoL, to be able to inform patients of the treatment benefits and risk of postoperative dysfunctions. The aim of our study is to review the current literature to determine to what degree the QoL of patients who underwent a rectal resection decreases, which domains are the most affected and, in addition, to establish the influence of different surgical techniques and approaches on functional outcomes.

Population-based study of morbidity risk associated with pathological complete response after chemoradiotherapy for rectal cancer

Background

Neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer may induce a pathological complete response (pCR) but increase surgical morbidity due to radiation-induced fibrosis. In this study the association between pCR and postoperative surgical morbidity was investigated.

Methods

Patients in the Netherlands with rectal cancer who underwent nCRT followed by total mesorectal excision between 2009 and 2017 were included. Data were stratified into patients who underwent resection with creation of a primary anastomosis and those who had a permanent stoma procedure. The association between pCR and postoperative morbidity was investigated in univariable and multivariable logistic regression analyses.

Results

pCR was observed in 976 (12·2 per cent) of 8003 patients. In 3472 patients who had a primary anastomosis, the presence of pCR was significantly associated with surgical complications (122 of 443 (27·5 per cent) versus 598 of 3029 (19·7 per cent) in those without pCR) and anastomotic leak (35 of 443 (7·9 per cent) versus 173 of 3029 (5·7 per cent) respectively). Multivariable analysis also showed associations between pCR and surgical complications (adjusted odds ratio (OR) 1·53, 95 per cent c.i. 1·22 to 1·92) and pCR and anastomotic leak (adjusted OR 1·41, 1·03 to 2·05). Of 4531 patients with a permanent stoma, surgical complications were observed in 120 (22·5 per cent) of 533 patients with a pCR, compared with 798 (20·0 per cent) of 3998 patients with no pCR (adjusted OR 1·17, 0·94 to 1·46).

Conclusion

Patients with a pCR in whom an anastomosis was created were at increased risk of developing an anastomotic leak.

Organ Preservation in cT2N0 Rectal Cancer After Neoadjuvant Chemoradiation Therapy: The Impact of Radiation Therapy Dose-escalation and Consolidation Chemotherapy

OBJECTIVE

To demonstrate the difference in organ-preservation rates and avoidance of definitive surgery among cT2N0 rectal cancer patients undergoing 2 different chemoradiation (CRT) regimens.

BACKGROUND

Patients with cT2N0 rectal cancer are more likely to develop complete response to neoadjuvant CRT. Organ preservation has been considered an alternative treatment strategy for selected patients. Radiation dose-escalation and consolidation chemotherapy have been associated with increased rates of response and may improve chances of organ preservation among these patients.

METHODS

Patients with distal and nonmetastatic cT2N0 rectal cancer managed by neoadjuvant CRT were retrospectively reviewed. Patients undergoing standard CRT (50.4 Gy and 2 cycles of 5-FU-based chemotherapy) were compared with those undergoing extended CRT (54 Gy and 6 cycles of 5-FU-based chemotherapy). Patients were assessed for tumor response at 8 to 10 weeks. Patients with complete clinical response (cCR) underwent organ-preservation strategy ("Watch and Wait"). Patients were referred to salvage surgery in the event of local recurrence during follow-up.

RESULTS

Thirty-five patients underwent standard and 46 patients extended CRT. Patients undergoing extended CRT were more likely to undergo organ preservation and avoid definitive surgical resection at 5years (67% vs 30%; P = 0.001). After development of a cCR, surgery-free survival is similar between extended and standard CRT groups at 5 years (78% vs 56%; P = 0.12).

CONCLUSIONS

Dose-escalation and consolidation chemotherapy leads to increased long-term organ-preservation rates among cT2N0 rectal cancer. After achievement of a cCR, the risk for local recurrence and need for salvage surgery is similar, irrespective of the CRT regimen.

"Watch and Wait" for complete clinical response after neoadjuvant chemoradiotherapy for rectal cancer

The management of rectal cancer has evolved substantially over recent decades, becoming increasingly complex. This was once a disease associated with high mortality and limited treatment options that typically necessitated a permanent colostomy, has now become a model for multidisciplinary evaluation, treatment and surgical advancement. Despite advances in the rates of total mesorectal excision, decreased local recurrence and increased 5-year survival rates, the multimodal treatment of rectal cancer is associated with a significant impact on long-term functional and quality of life outcomes including risks of bowel, bladder and sexual dysfunction, and potential need for a permanent stoma. There is great interest in strategies to decrease the toxicity of treatment, including selective use of radiation, chemotherapy or even surgery. The modern concept of selective use of surgery for patients with rectal cancer are based on the observed pathological complete response in approximately 10-20% of patients following long-course chemoradiation therapy. While definitive surgical resection remains the standard of care for all patients with non-metastatic rectal cancer, a growing number of studies are providing supportive evidence for a watch-and-wait, organ preserving approach in highly selected patients with rectal cancer. However, questions regarding the heterogeneity of patient selection, optimal method for inducing pathological complete response, methods and intervals for assessing treatment response and adequacy of follow-up remain unanswered. The aim of this review is to provide an up-to-date summary of the current evidence for the watch-and-wait management of rectal cancer following a complete clinical response after neoadjuvant chemoradiation.

The Effects of Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer-The Impact in Intratumoral Heterogeneity

Purpose: Intratumoral genetic heterogeneity (ITGH) is a common feature of solid tumors. However, little is known about the effect of neoadjuvant chemoradiation (nCRT) in ITGH of rectal tumors that exhibit poor response to nCRT. Here, we examined the impact of nCRT in the mutational profile and ITGH of rectal tumors and its adjacent irradiated normal mucosa in the setting of incomplete response to nCRT.

Methods and Materials: To evaluate ITGH in rectal tumors, we analyzed whole-exome sequencing (WES) data from 79 tumors obtained from The Cancer Genome Atlas (TCGA). We also compared matched peripheral blood cells, irradiated normal rectal mucosa and pre and post-treatment tumor samples (PRE-T and POS-T) from one individual to examine the iatrogenic effects of nCRT. Finally, we performed WES of 7 PRE-T/POST-T matched samples to examine how nCRT affects ITGH. ITGH was assessed by quantifying subclonal mutations within individual tumors using the Mutant-Allele Tumor Heterogeneity score (MATH score).

Results: Rectal tumors exhibit remarkable ITGH that is ultimately associated with disease stage (MATH score stage I/II 35.54 vs. stage III/IV 44.39, p = 0.047) and lymph node metastasis (MATH score N0 35.87 vs. N+ 45.79, p = 0.026). We also showed that nCRT does not seem to introduce detectable somatic mutations in the irradiated mucosa. Comparison of PRE-T and POST-T matched samples revealed a significant increase in ITGH in 5 out 7 patients and MATH scores were significantly higher after nCRT (median 41.7 vs. 28.8, p = 0.04). Finally, we were able to identify a subset of “enriched mutations” with significant changes in MAFs between PRE-T and POST-T samples. These “enriched mutations” were significantly more frequent in POST-T compared to PRE-T samples (92.9% vs. 7.1% p < 0.00001) and include mutations in genes associated with genetic instability and drug resistance in colorectal cancer, indicating the expansion of tumor cell subpopulations more prone to resist to nCRT.

Conclusions: nCRT increases ITGH and may result in the expansion of resistant tumor cell populations in residual tumors. The risk of introducing relevant somatic mutations in the adjacent mucosa is minimal but non-responsive tumors may have potentially worse biological behavior when compared to their untreated counterparts. This was an exploratory study, and due to the limited number of samples analyzed, our results need to be validated in larger cohorts.

Prediction of tumor response of rectal cancer cells via 3D cell culture and in vitro cytotoxicity assay before initiating preoperative chemoradiotherapy

The aim of the present study was to investigate the utility of 3D cell culture and in vitro cytotoxicity assays, performed using cells derived from biopsies obtained prior to the initiation of preoperative chemoradiotherapy (preop-CRT), in predicting tumor response to chemoradiotherapy following preop-CRT in rectal cancer. Biopsies were obtained from 49 patients with locally advanced rectal cancer that underwent preop-CRT between August 2015 and March 2017. Tumor tissue was obtained before initiating preop-CRT. The response to chemoradiation was assessed by in vitro cytotoxicity assay following 3D cell culture and radiation treatment. The associations between the results from the cytotoxicity assay, and tumor regression grade (TRG) and yp node (ypN) positivity were investigated. Among 49 patients, 26 patients were available for analysis. Cytotoxicity ranged from 25.5-72.6% (median, 47.6%). There was no difference in cytotoxicity according to the TRGs 1-5 (P=0.940), or good tumor response (TRGs 1-2 vs. TRGs 3-5; P=0.729). However, there was a significant difference in cytotoxicity between the ypN-negative and -positive groups (53.2±14.1 and 38.7±10.1, respectively; P=0.021). Following dichotomization of patients with 45% cut-off value, the cytotoxicity assay was the only factor that predicted ypN positivity in multivariate analysis (odds ratio, 13; 95% confidence interval, 1.2-133.2; P=0.031). In conclusion, the cytotoxicity assay using the 3D cell culture method can be used to predict tumor response, particularly ypN positivity, in patients with rectal cancer who are scheduled for preop-CRT.

Role of magnetic resonance imaging in organ-preserving strategies for the management of patients with rectal cancer

Total mesorectal excision has been the most effective treatment strategy adopted to reduce local recurrence rates among patients with rectal cancer. The morbidity associated with this radical surgical procedure led surgeons to challenge the standard therapy particularly when dealing with superficial lesions or good responders after neoadjuvant radiotherapy, to which radical surgery may be considered overtreatment. In this subset of patients, less invasive procedures in an organ-preserving strategy may result in good oncological and functional outcomes. In order to tailor the most appropriate treatment option, accurate baseline staging and reassessment of tumor response are relevant. MRI is the most robust tool for the precise selection of patients that are candidates for organ preservation; therefore, radiologists must be familiar with the criteria used to guide the management of these patients. The purpose of this article is to review the relevant features that radiologists should know in order to provide valuable information during the multidisciplinary discussion and ultimate management decision.

Increased Levels of Genomic Instability and Mutations in Homologous Recombination Genes in Locally Advanced Rectal Carcinomas

Pre-operative 5-fluoracil-based chemoradiotherapy (nCRT) is the standard treatment for patients with locally advanced rectal cancer (LARC). Patients with pathological complete response (pCR–0% of tumor cells in the surgical specimen after nCRT) have better overall survival and lower risk of recurrence in comparison with incomplete responders (pIR). Predictive biomarkers to be used for new therapeutic strategies and capable of stratifying patients to avoid overtreatment are needed. We evaluated the genomic profiles of 33 pre-treatment LARC biopsies using SNP array and targeted-next generation sequencing (tNGS). Based on the large number of identified genomic alterations, we calculated the genomic instability index (GII) and three homologous recombination deficiency (HRD) scores, which have been reported as impaired DNA repair markers. We observed high GII in our LARC cases, which was confirmed in 165 rectal cancer cases from TCGA. Patients with pCR presented higher GII compared with pIR. Moreover, a negative correlation between GII and the fraction of tumor cells remaining after surgery was observed (ρ = –0.382, P = 0.02). High HRD scores were detected in 61% of LARC, of which 70% were incomplete responders. Using tNGS (105 cancer-related genes, 13 involved in HR and 5 in mismatch repair pathways), we identified 23% of cases with mutations in HR genes, mostly in pIR cases (86% of mutated cases). In agreement, the analysis of the TCGA dataset (N = 145) revealed 21% of tumors with mutations in HR genes. The HRD scores were shown to be predictive of better response to PARP-inhibitors and platinum-based chemotherapy in breast and ovarian cancer. Our results suggest that the same strategy could be applied in a set of LARC patients with HRD. In conclusion, we identified high genomic instability in LARC, which was related to alterations in the HR pathway, especially in pIR. These findings suggest that patients with impaired HRD would clinically benefit from PARP-inhibitors and platinum-based therapy.

[Quality indicators for surgery of rectal cancer : Evidence-based development of a set of indicators for quality]

The definition of valid quality indicators is an essential task of medical self-administration and quality assurance. Based on the literature and the results of the Study, Documentation, and Quality Center (StuDoQ) Rectal Cancer Registry, we suggest the following QIs: rate of circumferential resection margin (CRM) positive resected material, rate of anastomotic leak in patients with anastomoses, rate of abdominal wound healing disorders and rate of patients with newly established permanent urinary diversion. Additionally, a new marker, the MTL30, which subsumes patient death within 30 days after the index operation, patient transfer to another acute hospital within 30 days after the index operation or a length of inpatient hospital stay of more than 30 days.