Pembrolizumab in soft-tissue sarcomas with tertiary lymphoid structures: a phase 2 PEMBROSARC trial cohort.

Immune checkpoint inhibitors (ICIs) show limited clinical activity in patients with advanced soft-tissue sarcomas (STSs). Retrospective analysis suggests that intratumoral tertiary lymphoid structures (TLSs) are associated with improved outcome in these patients. PEMBROSARC is a multicohort phase 2 study of pembrolizumab combined with low-dose cyclophosphamide in patients with advanced STS (NCT02406781). The primary endpoint was the 6-month non-progression rate (NPR). Secondary endpoints included objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and safety. The 6-month NPR and ORRs for cohorts in this trial enrolling all comers were previously reported; here, we report the results of a cohort enrolling patients selected based on the presence of TLSs (n = 30). The 6-month NPR was 40% (95% confidence interval (CI), 22.7-59.4), so the primary endpoint was met. The ORR was 30% (95% CI, 14.7-49.4). In comparison, the 6-month NPR and ORR were 4.9% (95% CI, 0.6-16.5) and 2.4% (95% CI, 0.1-12.9), respectively, in the all-comer cohorts. The most frequent toxicities were grade 1 or 2 fatigue, nausea, dysthyroidism, diarrhea and anemia. Exploratory analyses revealed that the abundance of intratumoral plasma cells (PCs) was significantly associated with improved outcome. These results suggest that TLS presence in advanced STS is a potential predictive biomarker to improve patients' selection for pembrolizumab treatment.

Time to next treatment or death as a candidate surrogate endpoint for overall survival in advanced melanoma patients treated with immune checkpoint inhibitors: an insight from the phase III CheckMate 067 trial.

BACKGROUND: Time to next treatment or death (TNT-D) may be a patient-relevant endpoint in patients treated with immune checkpoint inhibitors. This study investigated TNT-D as a surrogate endpoint (SE) for overall survival (OS) in previously untreated advanced melanoma patients. METHODS: Patient-level data from the 60-month results of the CheckMate 067 randomised, controlled trial were used. Analyses were carried out for nivolumab monotherapy or nivolumab with ipilimumab versus ipilimumab monotherapy. The SE 1-step validation method based on a joint frailty-copula model was used where the country of enrolment was applied to define clusters. Kendall's τ and the coefficient of determination (R2trial) were estimated for respective measurements of association at the individual and cluster levels. The surrogate threshold effect, the maximum threshold hazard ratio for TNT-D that would translate into OS benefit, was estimated. A leave-one-out cross-validation analysis was carried out to evaluate model robustness. RESULTS: Fifteen clusters of data were generated from 945 patients. For both nivolumab-containing arms, the association between TNT-D and OS was deemed acceptable at the individual level (Kendall's τ > 0.60) and strong at the cluster level, with R2trial fairly close to 1, with narrow confidence intervals. The estimated surrogate threshold effects were 0.61 for nivolumab versus ipilimumab and 0.49 for nivolimub + ipilimumab versus ipilimumab. Cross-validation results showed minimum variation of the correlation measures and satisfactory predictive accuracy for the model. CONCLUSION: Results suggest that TNT-D may be a valuable SE in previously untreated advanced melanoma patients treated with immune checkpoint inhibitors. Surrogacy analyses considering multiple randomised controlled trials are warranted for confirming these findings.

Optimal biological dose: a systematic review in cancer phase I clinical trials.

BACKGROUND: Classical phase 1 dose-finding designs based on a single toxicity endpoint to assess the maximum tolerated dose were initially developed in the context of cytotoxic drugs. With the emergence of molecular targeted agents and immunotherapies, the concept of optimal biological dose (OBD) was subsequently introduced to account for efficacy in addition to toxicity. The objective was therefore to provide an overview of published phase 1 cancer clinical trials relying on the concept of OBD. METHODS: We performed a systematic review through a computerized search of the MEDLINE database to identify early phase cancer clinical trials that relied on OBD. Relevant publications were selected based on a two-step process by two independent readers. Relevant information (phase, type of therapeutic agents, objectives, endpoints and dose-finding design) were collected. RESULTS: We retrieved 37 articles. OBD was clearly mentioned as a trial objective (primary or secondary) for 22 articles and was traditionally defined as the smallest dose maximizing an efficacy criterion such as biological target: biological response, immune cells count for immunotherapies, or biological cell count for targeted therapies. Most trials considered a binary toxicity endpoint defined in terms of the proportion of patients who experienced a dose-limiting toxicity. Only two articles relied on an adaptive dose escalation design. CONCLUSIONS: In practice, OBD should be a primary objective for the assessment of the recommended phase 2 dose (RP2D) for a targeted therapy or immunotherapy phase I cancer trial. Dose escalation designs have to be adapted accordingly to account for both efficacy and toxicity.

GUIP1: a R package for dose escalation strategies in phase I cancer clinical trials.

BACKGROUND: The main objective of phase I cancer clinical trials is to identify the maximum tolerated dose, usually defined as the highest dose associated with an acceptable level of severe toxicity during the first cycle of treatment. Several dose-escalation designs based on mathematical modeling of the dose-toxicity relationship have been developed. The main ones are: the continual reassessment method (CRM), the escalation with overdose control (EWOC) method and, for late-onset and cumulative toxicities, the time-to-event continual reassessment method (TITE-CRM) and the time-to-event escalation with overdose control (TITE-EWOC) methods. The objective of this work was to perform a user-friendly R package that combines the latter model-guided adaptive designs. RESULTS: GUIP1 is an R Graphical User Interface for dose escalation strategies in Phase 1 cancer clinical trials. It implements the CRM (based on Bayesian or maximum likelihood estimation), EWOC and TITE-CRM methods using the dfcrm and bcrm R packages, while the TITE-EWOC method has been specifically developed. The program is built using the TCL/TK programming language, which can be compiled via R software libraries (tcltk, tkrplot, tcltk2). GUIP1 offers the possibility of simulating and/or conducting and managing phase I clinical trials in real-time using file management options with automatic backup of study and/or simulation results. CONCLUSIONS: GUIP1 is implemented using the software R, which is widely used by statisticians in oncology. This package simplifies the use of the main model-based dose escalation methods and is designed to be fairly simple for beginners in R. Furthermore, it offers multiple possibilities such as a full traceability of the study. By including multiple innovative adaptive methods in a free and user-friendly program, we hope that GUIP1 will promote and facilitate their use in designing future phase I cancer clinical trials.

Contrast-enhanced intra-operative ultrasound as a clinical decision making tool during surgery for colorectal liver metastases: The ULIIS study.

BACKGROUND: Detecting more colorectal liver metastases (CRLMs) during surgery may help optimise strategy and improve outcomes. Our objective was to determine clinical utility (CU) of contrast-enhanced intra-operative ultrasound (CE-IOUS) using sulphur hexafluoride microbubbles during CRLM surgery. METHOD: A prospective phase II trial performed at two comprehensive cancer research centres. Patients operated for CRLMs were eligible and assessable if intra-operative ultrasound (IOUS) and CE-IOUS had been performed and pathological results were available and/or 3-month imaging. CU was defined as the justified change in planned surgical strategy or procedure using CE-IOUS. RESULTS: Out of the 68 patients enrolled, 54 were eligible and assessable. 43 patients underwent pre-operative chemotherapy. The median number of CRLMs was 2 (range, 1-11). Pre-operative staging was performed using MRI. IOUS allowed identification of 45 new CRLMs in 13 (24.7%) patients. Compared to IOUS, CE-IOUS allowed identification of 10 additional CRLMs in 9 (16.7%) patients. Surgery was altered and justified in 4 patients only, leading to a CU rate of 7.70% (95 CI, [3.2, 18.6]). No missing CRLMs were identified by CE-IOUS. CONCLUSIONS: Although the primary endpoint was not met for one protocol violation, secondary endpoints indicate that CE-IOUS has an intermediate added-value for surgeons treating CRLMs. TRIAL REGISTRATION: NCT01880554 (https://clinicaltrials.gov/).

Multidisciplinary development of the Geriatric Core Dataset for clinical research in older patients with cancer: A French initiative with international survey.

BACKGROUND: To define a core set of geriatric data to be methodically collected in clinical cancer trials of older adults, enabling comparison across trials. PATIENTS AND METHODS: Following a consensus approach, a panel of 14 geriatricians from oncology clinics identified seven domains of importance in geriatric assessment. Based on the international recommendations, geriatricians selected the mostly commonly used tools/items for geriatric assessment by domain (January-October 2015). The Geriatric Core Dataset (G-CODE) was progressively developed according to RAND appropriateness ratings and feedback during three successive Delphi rounds (July-September 2016). The face validity of the G-CODE was assessed with two large panels of health professionals (55 national and 42 international experts) involved both in clinical practice and cancer trials (March-September 2017). RESULTS AND DISCUSSION: After the last Delphi round, the tools/items proposed for the G-CODE were the following: (1) social assessment: living alone or support requested to stay at home; (2) functional autonomy: Activities of Daily Living (ADL) questionnaire and short instrumental ADL questionnaire; (3) mobility: Timed Up and Go test; (4) nutrition: weight loss during the past 6 months and body mass index; (5) cognition: Mini-Cog test; (6) mood: mini-Geriatric Depression Scale and (7) comorbidity: updated Charlson Comorbidity Index. More than 70% of national experts (42 from 20 cities) and international experts (31 from 13 countries) participated. National and international surveys showed good acceptability of the G-CODE. Specific points discussed included age-year cut-off, threshold of each tool/item and information about social support, but no additional item was proposed. CONCLUSION: We achieved formal consensus on a set of geriatric data to be collected in cancer trials of older patients. The dissemination and prospective use of the G-CODE is needed to assess its utility.

Radiofrequency ablation of stage IA non-small cell lung cancer in patients ineligible for surgery: results of a prospective multicenter phase II trial.

BACKGROUND: A prospective multicenter phase II trial to evaluate the survival outcomes of percutaneous radiofrequency ablation (RFA) for patients with stage IA non-small cell lung cancer (NSCLC), ineligible for surgery. METHODS: Patients with a biopsy-proven stage IA NSCLC, staging established by a positron emission tomography-computed tomography (PET-CT), were eligible. The primary objective was to evaluate the local control of RFA at 1-year. Secondary objectives were 1- and 3-year overall survival (OS), 3-year local control, lung function (prior to and 3 months after RFA) and quality of life (prior to and 1 month after RFA). RESULTS: Of the 42 patients (mean age 71.7 y) that were enrolled at six French cancer centers, 32 were eligible and assessable. Twenty-seven patients did not recur at 1 year corresponding to a local control rate of 84.38% (95% CI, [67.21-95.72]). The local control rate at 3 years was 81.25% (95% CI, [54.35-95.95]). The OS rate was 91.67% (95% CI, [77.53-98.25]) at 1 year and 58.33% (95% CI, [40.76-74.49]) at 3 years. The forced expiratory volume was stable in most patients apart from two, in whom we observed a 10% decrease. There was no significant change in the global health status or in the quality of life following RFA. CONCLUSION: RFA is an efficient treatment for medically inoperable stage IA NSCLC patients. RFA is well tolerated, does not adversely affect pulmonary function and the 3-year OS rate is comparable to that of stereotactic body radiotherapy, in similar patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01841060 registered in November 2008.

Alterations in comprehensive geriatric assessment decrease survival of elderly patients with cancer.

INTRODUCTION: A comprehensive geriatric assessment (CGA) evaluating several domains of health is recommended for elderly patients with cancer. Effects of altered domains on the risk of death in this population need to be clarified. The aim of this study was to estimate the independent association of each CGA domain to overall survival (OS). METHOD: Patients included in the ONCODAGE cohort completed a CGA at baseline. Cox models (one per domain) estimated the hazard ratio (HR) of death for each CGA domain. Directed Acyclic Graphs (DAGs) selected specific sets of adjustment factors for each model. RESULTS: The analysis included 1264 patients (mean age: 78 years, women: 70%). Median follow-up was 5.2 years, and 446 patients died. Each altered domain had a detrimental effect on survival, sometimes dependent on gender, age, education or time from inclusion. Nutritional status had a time-varying effect, with higher mortality rates if altered only within the first 3 years of follow-up. In case of altered mobility, the risk of death was higher only for the youngest patients and, in case of altered autonomy, only for the youngest women. An altered neurological state led to higher mortality rates; this effect increased with the level of education. Patients with altered psychological status or more than four comorbidities at baseline had also higher mortality rates. CONCLUSIONS: Patients with an altered CGA domain have a higher risk of death than those without any alteration. The effect of some alterations is different in some subgroups or at a given time of the treatments.

Modeling individual and relative accuracy of screening tools in geriatric oncology.

BACKGROUND: Classification probabilities reflect to what degree a screening test represents the true disease state and include true positive (TPF) and false positive fractions (FPF). With two tests, one can compare TPF and FPF using relative probabilities which offer advantages in terms of interpretation and statistical modeling. Our objective was to highlight how individual and relative TPF and FPF can be easily estimated and compared within a regression modeling framework. This allows the modeling of tests' accuracy while adjusting for multiple covariates, and thus provides valuable information in addition to the crude TPF and FPF. We illustrate our purpose with the G8 and VES-13 screening tests aimed at identifying elderly cancer patients in need for a comprehensive geriatric assessment (CGA). METHODS: Prospective cohort with a paired design. TPF and FPF of each test, as well as relative TPF and FPF were modeled using log-linear models. RESULTS: G8 detected patients in need for CGA better than VES-13 at the expense of misclassifying a large number of normal patients. Both tests had better TPF with older age and poorer performance status (PS), and for all cancer subtypes compared with prostate cancer. Effect of age and PS on TPF was more pronounced with VES-13. Age affected FPF, but not differentially. CONCLUSIONS: Regression modeling helps provide a thorough assessment of the accuracy of diagnostic tests and should be used more frequently. In the context of screening, we encourage the use of G8 as failing to identify patients in need of a CGA might be more problematic than over-detection. Moreover, although we identified variables associated with the sensitivity of these tests, this association was less pronounced for the G8.

[How to identify frailty in older patients with cancer? Available tools]. / Comment identifier les personnes âgées fragiles ? Outils à disposition.

Management of cancer in the elderly needs more attention than in younger patients mainly because of comorbidities and geriatric syndromes. Each frailty encountered will facilitate adverse events and complications which are more frequent and more severe in the elderly and have to be anticipated to control for the risk of organ failure and dependencies. Fortunately, tools which have been developed and validated by geriatricians, are available to the oncologists and their validity has been demonstrated in oncology. Yet, they are quite time-consuming and consequently available for a minority of patients. Furthermore, it appears that some of the older patients can be proposed standard therapy and do not need the intervention of geriatricians. This is the reason why screening tools have been developed and validated among which the G8 questionnaire appears to be one of the best. This approach is beginning to be implemented in the daily routine in France and abroad but their appropriate use according to cancer types and treatment intensity should be further improved for the benefit of our patients.

Aplidin in patients with advanced dedifferentiated liposarcomas: a French Sarcoma Group Single-Arm Phase II study.

BACKGROUND: Preclinical data have suggested a therapeutic role of JUN pathway activation in dedifferentiated liposarcoma (DDLPS) tumorigenesis. Aplidin is a drug inducing apoptosis through a strong, sustained activation of c-Jun NH2-terminal kinase. METHODS: This phase II trial included patients with progressive advanced DDLPS. They received Aplidin 5 mg/m(2) days 1-15, 28-day cycle until disease progression or unacceptable toxicity. The primary end point was the 3-month nonprogression rate (PFS3) defined as the proportion of patients with nonprogressive disease at 3 months. A PFS3 of 40% considered as a reasonable objective to claim drug efficacy. RESULTS: Between August 2012 and May 2013, 24 patients were included. Sixteen had received prior chemotherapy. Twenty-two were assessable for efficacy. The PFS3 was 9.1% [95% confidence interval (CI) 1.1-29.2]. Median progression-free and overall survivals were 1.6 months (95% CI 1.4-2.6) and 9.2 months (95% CI 6.6-). The most frequent adverse events of any grade were nausea, fatigue, anorexia, vomiting and diarrhea. CONCLUSION: Aplidin did not meet the primary end point of this trial and do not deserve further investigation in DDLPS. CLINICALTRIALSGOV IDENTIFIER: NCT01876043.

Guidelines for time-to-event end point definitions in breast cancer trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†.

BACKGROUND: Using surrogate end points for overall survival, such as disease-free survival, is increasingly common in randomized controlled trials. However, the definitions of several of these time-to-event (TTE) end points are imprecisely which limits interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points. The DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for randomized cancer clinical trials (RCTs) in breast cancer. PATIENTS AND METHODS: A literature review was carried out to identify TTE end points (primary or secondary) reported in publications of randomized trials or guidelines. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points based on a validated consensus method that formalize the degree of agreement among experts. RESULTS: Recommended guidelines for the definitions of TTE end points commonly used in RCTs for breast cancer are provided for non-metastatic and metastatic settings. CONCLUSION: The use of standardized definitions should facilitate comparisons of trial results and improve the quality of trial design and reporting. These guidelines could be of particular interest to those involved in the design, conducting, reporting, or assessment of RCT.

Guidelines for time-to-event end point definitions in sarcomas and gastrointestinal stromal tumors (GIST) trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†.

BACKGROUND: The use of potential surrogate end points for overall survival, such as disease-free survival (DFS) or time-to-treatment failure (TTF) is increasingly common in randomized controlled trials (RCTs) in cancer. However, the definition of time-to-event (TTE) end points is rarely precise and lacks uniformity across trials. End point definition can impact trial results by affecting estimation of treatment effect and statistical power. The DATECAN initiative (Definition for the Assessment of Time-to-event End points in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for RCT in sarcomas and gastrointestinal stromal tumors (GIST). METHODS: We first carried out a literature review to identify TTE end points (primary or secondary) reported in publications of RCT. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points. Recommendations were developed through a validated consensus method formalizing the degree of agreement among experts. RESULTS: Recommended guidelines for the definition of TTE end points commonly used in RCT for sarcomas and GIST are provided for adjuvant and metastatic settings, including DFS, TTF, time to progression and others. CONCLUSION: Use of standardized definitions should facilitate comparison of trials' results, and improve the quality of trial design and reporting. These guidelines could be of particular interest to research scientists involved in the design, conduct, reporting or assessment of RCT such as investigators, statisticians, reviewers, editors or regulatory authorities.

Adherence to consensus-based diagnosis and treatment guidelines in adult soft-tissue sarcoma patients: a French prospective population-based study.

BACKGROUND: Soft-tissue sarcomas (STSs) are rare tumors with varied histological presentations. Management and treatment are thus complex, but crucial for patient outcomes. We assess adherence to adult STS management guidelines across two French regions (10% of the French population). We also report standardized incidence. PATIENTS AND METHODS: STS patients diagnosed from 1 November 2006 to 31 December 2007 were identified from pathology reports, medical hospital records, and cancer registries. Guideline adherence was assessed by 23 criteria (validated by Delphi consensus method), and age and sex-standardized incidence rates estimated. Associations between patient, treatment, and institutional factors and adherence with three major composite criteria relating to diagnostic imaging and biopsy as well as multidisciplinary team (MDT) case-review are reported. RESULTS: Two hundred and seventy-four patients were included (57.7% male, mean age 60.8 years). Practices were relatively compliant overall, with over 70% adherence for 10 criteria. Three criteria with perfect Delphi consensus had low adherence: receiving histological diagnosis before surgery, adequacy of histological diagnosis (adherence around 50% for both), and MDT discussion before surgery (adherence <30%). Treatment outside of specialized centers was associated with lower adherence for all three composite criteria, and specific tumor sites and/or features were associated with lower adherence for diagnostic imaging, methods, and MDT meetings. STS standardized incidence rates were 4.09 (European population) and 3.33 (World) /100 000 inhabitants. CONCLUSIONS: Initial STS diagnosis and treatment across all stages (imaging, biopsy, and MDT meetings) need improving, particularly outside specialized centers. Educational interventions to increase surgeon's sarcoma awareness and knowledge and to raise patients' awareness of the importance of seeking expert care are necessary.

GDC-0449 in patients with advanced chondrosarcomas: a French Sarcoma Group/US and French National Cancer Institute Single-Arm Phase II Collaborative Study.

BACKGROUND: Pre-clinical data have suggested a therapeutic role of Hedgehog (Hh) pathway inhibitors in chondrosarcoma. METHODS: This phase II trial included patients with progressive advanced chondrosarcoma. They received GDC-0449 150 mg/day (days 1-28, 28-day cycle). The primary end point was the 6-month clinical benefit rate (CBR) defined as the proportion of patients with non-progressive disease at 6 months. A 6-month CBR of 40% was considered as a reasonable objective to claim drug efficacy. RESULTS: Between February 2011 and February 2012, 45 patients were included. Twenty had received prior chemotherapy. Thirty-nine were assessable for efficacy. The 6-month CBR was 25.6% (95% confidence interval 13.0-42.1). All stable patients had grade 1 or 2 conventional chondrosarcoma with documented progression within the 6 months before inclusion. All but one with available data also had overexpression of the Hh ligand. Median progression-free and overall survivals were 3.5 and 12.4 months, respectively. The most frequent adverse events were grade 1 or 2 myalgia, dysgeusia and alopecia. CONCLUSIONS: GDC-0449 did not meet the primary end point of this trial. Results suggest some activity in a subset of patients with progressive grade 1 or 2 conventional chondrosarcoma. Further studies assessing its role in combination with chemotherapy are warranted. CLINICALTRIALSGOV IDENTIFIER: NCT01267955.

Screening older cancer patients: first evaluation of the G-8 geriatric screening tool.

BACKGROUND: Development of a geriatric screening tool is necessary to identify elderly cancer patients who would benefit from comprehensive geriatric assessment (CGA). We develop and evaluate the G-8 screening tool against various reference tests. PATIENTS AND METHODS: Analyses were based on 364 cancer patients aged>70 years scheduled to receive first-line chemotherapy included in a multicenter prospective study. The G-8 consists of seven items from the Mini Nutritional Assessment (MNA) questionnaire and age. Our primary reference test is based on a set of seven CGA scales: Activities Daily Living (ADL), Instrumental ADL, MNA, Mini-Mental State Exam, Geriatric Depression Scale, Cumulative Illness Rating Scale-Geriatrics, and Timed Get Up and Go. We considered the presence of at least one questionnaire with an impaired score as an abnormal reference exam. Additional reference exams are also discussed. RESULTS: The prevalence of being at risk varied from 60% to 94% according to the various definitions of the reference test. When considering the primary reference test, a cut-off value of 14 for the G-8 tool provided a good sensitivity estimate (85%) without deteriorating the specificity excessively (65%). CONCLUSION: The G-8 shows good screening properties for identifying elderly cancer patients who could benefit from CGA.

Delayed colo-anal anastomosis is an alternative to prophylactic diverting stoma after total mesorectal excision for middle and low rectal carcinomas.

BACKGROUND: After total mesorectal excision (TME), a low colorectal or colo-anal anastomosis is usually performed. A prophylactic covering stoma is often used, especially for patients receiving neoadjuvant chemo-radiotherapy. However, morbidity is high, mainly due to anastomotic leakage. METHODS: From May 2000 to October 2008, patients with middle or low rectal cancer who underwent a trans-anal pull-through procedure after TME were prospectively recorded. No covering stoma was performed in these patients. However, they all underwent a delayed colo-anal anastomosis (DCA), which was performed 6 days following the TME, on average. Both the surgical technique and follow-up were standardised. Patients with T3, T4 and/or N+ cancers were given preoperative radiotherapy. A retrospective analysis was done to assess post-operative mortality, morbidity, and oncologic and functional results. RESULTS: One hundred consecutive patients with rectal tumours at a median distance of 5 cm from the anal verge underwent DCA after TME. The 5-year overall and disease-free survival rates were 81% and 66%, respectively. The post-operative mortality rate was 3% and the overall post-operative morbidity rate was 36%, with only 3 anastomotic leakages. After two years, 73% of the patients had good functional outcomes. CONCLUSION: The trans-anal pull-through procedure after TME, followed by DCA seems to be a safe and efficient sphincter-preserving procedure to treat patients with middle or low rectal cancer while avoiding a prophylactic, diverting stoma.