Background Rectal cancer surgery is technically challenging and depends on many factors. This study evaluated the ability of clinical and anatomical factors to predict surgical difficulty in total mesorectal excision. Methods Consecutive patients who underwent total mesorectal excision for locally advanced rectal cancer in a laparoscopic, robotic or open procedure after neoadjuvant treatment, between 2005 and 2014, were included in this retrospective study. Preoperative clinical and MRI data were studied to develop a surgical difficulty grade. Results In total, 164 patients with a median age of 61 (range 26–86) years were considered to be at low risk (143, 87·2 per cent) or high risk (21, 12·8 per cent) of surgical difficulty. In multivariable analysis, BMI at least 30 kg/m² (P = 0·021), coloanal anastomosis (versus colorectal) (P = 0·034), intertuberous distance less than 10·1 cm (P = 0·041) and mesorectal fat area exceeding 20·7 cm² (P = 0·051) were associated with greater surgical difficulty. A four‐item score (ranging from 0 to 4), with each item (BMI, type of surgery, intertuberous distance and mesorectal fat area) scored 0 (absence) or 1 (presence), is proposed. Patients can be considered at high risk of a difficult or challenging operation if they have a score of 3 or more. Conclusion This simple morphometric score may assist surgical decision‐making and comparative study by defining operative difficulty before surgery.

Background Tumour extension beyond the mesorectal plane (ymrT4) occurs in 5–10 per cent of patients with rectal cancer and 10 per cent of patients develop locally recurrent rectal cancer (LRRC) after primary surgery. There is global variation in healthcare delivery for these conditions. Methods An international benchmark trial of the management of ymrT4 tumours and LRRC was undertaken in France and Australia between 2015 and 2017. Heterogeneity in management and operative decision‐making were analysed by comparison of surgical resection rates, blinded intercountry reading of pelvic MRI, quality‐of‐life assessment and qualitative evaluations. Results Among 154 patients (97 in France and 57 in Australia), 31·8 per cent had ymrT4 disease and 68·2 per cent LRRC. The surgical resection rates were 88 and 79 per cent in France and Australia respectively (P = 0·112). The concordance in operative planning was low (κ = 0·314); the rate of pelvic exenteration was lower in France than Australia both in clinical practice (36 of 78 versus 34 of 40; P < 0·001) and in theoretical conditions (10 of 25 versus 50 of 57; P = 0·002). The R0 resection rate was lower in France than Australia for LRRC (25 of 49 versus 18 of 21; P = 0·007) but not for ymrT4 tumours (21 of 26 versus 15 of 15; P = 0·139). Morbidity rates were similar. Patients who underwent non‐exenterative procedures had higher scores on the mental functioning subscale at 12 months (P = 0·047), and a lower level of distress at 6 months (P = 0·049). Qualitative analysis highlighted five categories of psychosocial factors influencing treatment decisions: patient, strategy, specialist, organization and culture. Conclusion This international benchmark trial has highlighted the differences in worldwide treatment of locally advanced and LRRC. Standardized care should improve outcomes for these patients.

The management of pT1a‐bN0M0 breast cancer remains an area of controversy. Data from 714 patients classified as having pT1a‐bN0M0 breast cancer and treated, from 1999 to 2004 in the Languedoc‐Roussillon France, were analyzed. The human epidermal growth factor receptor 2 (HER2) status analyses were centralized. The objective of this study was to describe the prognosis of pT1a‐bN0M0 breast cancer according to HER2 distribution and hormonal status. The median follow‐up was 6.4 years. Ten‐year overall survival was 94%. HER2 overexpression was observed in 6.1% of the patients. The 10‐year prognosis of patients with HER2‐positive tumors was worse than that of those with HER2‐negative (disease‐free survival 73% vs. 89%, P < 0.0001). Tumor size (T1a/T1b) was not a relevant prognostic factor. The co‐expression of HER2 with hormonal receptors (HR) was associated with high recurrence at 10 years. In both univariate and multivariate analyses, the most relevant prognostic factor for this population was HER2 amplification. In multivariate analysis, patients with HER2‐positive tumors had higher risk of mortality (HR, 3.89; 95% CI, 1.58–9.56). In pT1a‐bN0M0 breast cancers, HER2 amplification or overexpression is a risk factor for recurrence. In HER2‐positive breast cancers, HR expression is associated with a poor prognosis despite the hormone therapy. For this population, a personalized management may be required.

Radiomics may be useful in rectal cancer management. The aim of this study was to assess and compare different radiomics approaches over qualitative evaluation to predict disease-free survival (DFS) in patients with locally advanced rectal cancer treated with neoadjuvant therapy. Patients from a phase II, multicentre, randomized study (GRECCAR4; NCT01333709) were included retrospectively as a training set. An independent cohort of patients comprised the independent test set. For both time points and both sets, radiomic features were extracted from two-dimensional manual segmentation (MS), three-dimensional (3D) MS, and from bounding boxes. Radiomics predictive models of DFS were built using a hyperparameters-tuned random forests classifier. Additionally, radiomics models were compared with qualitative parameters, including sphincter invasion, extramural vascular invasion as determined by MRI (mrEMVI) at baseline, and tumour regression grade evaluated by MRI (mrTRG) after chemoradiotherapy (CRT). In the training cohort of 98 patients, all three models showed good performance with mean(s.d.) area under the curve (AUC) values ranging from 0.77(0.09) to 0.89(0.09) for prediction of DFS. The 3D radiomics model outperformed qualitative analysis based on mrEMVI and sphincter invasion at baseline (P = 0.038 and P = 0.027 respectively), and mrTRG after CRT (P = 0.017). In the independent test cohort of 48 patients, at baseline and after CRT the AUC ranged from 0.67(0.09) to 0.76(0.06). All three models showed no difference compared with qualitative analysis in the independent set. Radiomics models can predict DFS in patients with locally advanced rectal cancer.