Peritoneal carcinomatosis (PC) is an unmet medical need. Despite recent improvements, systemic chemotherapy has limited efficacy. We report the first appli

The diagnosis of most cancers is made by a board-certified pathologist based on a tissue biopsy under the microscope. Recent research reveals a high discordance between individual pathologists. For melanoma, the literature reports on 25-26% of discordance for classifying a benign nevus versus malignant melanoma. A recent study indicated the potential of deep learning to lower these discordances. However, the performance of deep learning in classifying histopathologic melanoma images was never compared directly to human experts. The aim of this study is to perform such a first direct comparison. A total of 695 lesions were classified by an expert histopathologist in accordance with current guidelines (350 nevi/345 melanoma). Only the haematoxylin & eosin (H&E) slides of these lesions were digitalised via a slide scanner and then randomly cropped. A total of 595 of the resulting images were used to train a convolutional neural network (CNN). The additional 100 H&E image sections were used to test the results of the CNN in comparison to 11 histopathologists. Three combined McNemar tests comparing the results of the CNNs test runs in terms of sensitivity, specificity and accuracy were predefined to test for significance (p < 0.05). The CNN achieved a mean sensitivity/specificity/accuracy of 76%/60%/68% over 11 test runs. In comparison, the 11 pathologists achieved a mean sensitivity/specificity/accuracy of 51.8%/66.5%/59.2%. Thus, the CNN was significantly (p = 0.016) superior in classifying the cropped images. With limited image information available, a CNN was able to outperform 11 histopathologists in the classification of histopathological melanoma images and thus shows promise to assist human melanoma diagnoses.

Background Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a novel technique of intraperitoneal chemotherapy. First results obtained with PIPAC in patients with advanced peritoneal metastasis (PM) from gastric cancer (GC) are presented. Methods Retrospective analysis: Sixty PIPAC were applied in 24 consecutive patients with PM from GC. 67 % patients had previous surgery, and 79 % previous platinum-based systemic chemotherapy. Mean Peritoneal Carcinomatosis Index (PCI) of 16 ± 10 and 18/24 patients had signet-ring GC. Cisplatin 7.5 mg/m² and doxorubicin 1.5 mg/m² were given for 30 min at 37 °C and 12 mmHg at 6 week intervals. Outcome criteria were survival, adverse events, and histological tumor response. Results Median follow-up was 248 days (range 105–748), and median survival time was 15.4 months. Seventeen patients had repeated PIPAC, and objective tumor response was observed in 12 (12/24 = 50 %): no vital tumor cells = 6, major pathological response = 6, minor response = 3. Postoperative adverse events > CTCAE 2 were observed in 9 patients (9/24, 37.5 %). In 3/17 patients, a later PIPAC could not be performed due to non-access. Two patients (ECOG 3 and 4) died in the hospital due to disease progression. Conclusion PIPAC with low-dose cisplatin and doxorubicin was safe and induced objective tumor regression in selected patients with PM from recurrent, platinum-resistant GC. First survival data are encouraging and justify further clinical studies in this indication.

Background : Multimodal therapeutic strategies have improved the outcome of peritoneal metastases (PM). However, objective assessment of therapy response remains difficult in PM, since radiological studies have a poor accuracy for low-volumetric disease. There is an obvious need for a histological gold standard allowing assessment of tumor response to treatment in PM. Content : We propose to perform peritoneal punch biopsies with a diameter of 3 to 5 mm in all four abdominal quadrants. We propose a four-tier Peritoneal Regression Grading Score (PRGS), defined as Grade 1: complete response (absence of tumor cells), Grade 2: major response (major regression features, few residual tumor cells), Grade 3: minor response (some regressive features but predominance of residual tumor cells), Grade 4: no response (tumor cells without any regressive features). Acellular mucin and infarct-like necrosis should be regarded as regression features. We recommend reporting the mean and the worst value of the regression grades obtained. When complete tumor response is suspected intraoperatively, a peritoneal cytology should be sampled. Summary : A generic, unique score for the assessment of histological tumor response to chemotherapy in PM makes sense because of the clinical impact of histological response to therapy and because the organ of metastasis (peritoneum) is the same. By adopting PRGS, different centers will be able to use a uniform terminology and grading that will allow meaningful comparison of their results. Outlook : PRGS has now to be validated in several gastrointestinal and gynecological cancer types and may be useful both in clinical and research settings.

Aim: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an experimental drug delivery method that applies chemotherapy into the abdominal cavity as an aerosol under pressure. We present the first results obtained with PIPAC in colorectal peritoneal metastasis (CPM).Method: This is a retrospective analysis. PIPAC was applied in 17 consecutive patients with pretreated CPM. All patients had previously undergone surgery, and 16 had undergone previous lines of systemic chemotherapy (median, two lines). The mean peritoneal metastasis index (peritoneal cancer index) was 16 ± 10. Forty‐eight applications of PIPAC with oxaliplatin (92 mg/m²) were given every 6 weeks at 37°C and 12 mmHg for 30 min. The outcome criteria were microscopic pathological response, survival and adverse events according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.Results: Forty‐eight PIPAC administrations were performed with no intra‐operative complications. The mean number of PIPAC administrations per patient was 2.8 (minimum one, maximum six). Postoperative adverse events (CTCAE level 3) were observed in four patients (23%), no CTCAE level‐4 adverse events were reported. The hospital mortality was zero. Objective tumour responses were observed in 12/17 patients (71%), and the overall responses were as follows: complete pathological response (seven patients), major response (four patients), partial response (one patient), no response (two patients) and not eligible (three patients). The mean survival after first PIPAC was 15.7 months.Conclusion: Repeated PIPAC with oxaliplatin can induce the regression of pretreated CPM. The toxicity appears to be low. These preliminary results are encouraging and justify prospective clinical studies.