Radiofrequency Combined with Intratumoral Immunotherapy: Preclinical Results and Safety in Metastatic Colorectal Carcinoma.

Radiofrequency ablation (RFA) of cancer induces an anti-tumor immunity, which is insufficient to prevent recurrences. In mice, RFA-intratumoral immunotherapy by granulocyte-macrophage colony-stimulating factor (GM-CSF) and Bacillus Calmette-Guerin resulted in complete metastases regression. Infectious risk in human needs replacement of live vaccines. Intratumoral purified protein derivatives (PPD) have never been tested in digestive cancers, and the safety of intratumoral immunotherapy after RFA has not yet been validated in human models. We investigated the therapeutic efficacy of combined radiofrequency ablation (RFA) and intratumoral immunotherapy (ITI) using an immune-muco-adherent thermogel (IMT) in a mouse model of metastatic colorectal cancer (CRC) and the safety of this approach in a pig model. Intratumoral stability of the immunogel was assessed using magnetic resonance imaging (MRI) and bioluminescent imaging. Seventy-four CT26 tumor-bearing female BALB/c mice were treated with RFA either alone or in combination with intratumoral IMT. Regression of distant metastasis and survival were monitored for 60 days. Six pigs that received liver radiofrequency and intralesional IMT injections were followed for 15 days. Experimental gel embolisms were treated using an intravascular approach. Pertinent rheology of IMT was confirmed in tumors, by the signal stability during 3 days in MRI and 7 days in bioluminescence imaging. In mice, the abscopal effect of RFA-intratumoral immunotherapy resulted in regression of distant lesions completed at day 16 vs. a volume of 350 ± 99.3 mm3 in the RFA group at day 25 and a 10-fold survival rate at 60 days. In pigs, injection of immunogel in the liver RFA area was safe after volume adjustment without clinical, hematological, and liver biology disorder. Flow cytometry showed an early increase in CD3 TCRγδ+T cells at D7 (p < 0.05) and a late decrease in CD29+-CD8 T cells at D15 (p < 0.05), reflecting the inflammation status changes. Systemic GM-CSF release was not detectable. Experimental caval and pulmonary thermogel embolisms were treated by percutaneous catheterism and cold serum infusion. RFA-intratumoral immunotherapy as efficient and safe mini-invasive interventional oncology is able to improve ablative treatment of colorectal liver metastases.

Safeness of Simultaneous Colonic Resection and Hepatic Radiofrequency Ablation.

Background and Objectives: Previous reports showed an increased risk of infectious complications when liver radiofrequency ablation (RFA) is performed simultaneously to colorectal resection. The aim of this study was to compare early and long-term outcomes of simultaneous versus staged strategy. Methods: Data from colorectal cancer liver metastases consecutively treated by surgery of the primary tumor with an associated liver RFA procedure between January 1, 2010 and January 31, 2020. Patients were divided into two groups: RFA performed during colorectal surgery (simultaneous) or in a different moment (staged). Patients were manually matched (1:1) to minimize influence of known covariates. Results: Seventy-two patients were included. After matching, there was no difference between the two groups in morbidity or mortality. Hospital stay was 2 days shorter in the simultaneous group. Conclusions: Early or long-term outcomes were identical between the two strategies. The simultaneous strategy was associated with a shorter duration of hospitalization although not significant. Simultaneous colorectal resection and liver RFA is safe and must be included in surgeons' armamentarium.

Mucoadhesive thermosensitive hydrogel for the intra-tumoral delivery of immunomodulatory agents, in vivo evidence of adhesion by means of non-invasive imaging techniques.

Intratumoral injection of biocompatible gels is increasingly used for the sustained delivery of drugs and vaccines to enhance the anti-cancer immune response. Granulocyte-macrophage colony stimulating factor (GM-CSF) has become an attractive adjuvant thanks to its ability to boost the antitumor immune response by inducing proliferation, maturation and migration of the dendritic-cells (DCs) and the differentiation of lymphocytes. Killed Mycobacteria, such as Heat-killed Mycobacterium tuberculosis (HKMT) have been used in several studies as TLR-2 agonist to increase maturation of DCs. In this study, we designed a mucoadhesive thermosensitive formulation for the local delivery of GM-CSF and HKMT in order to enhance DCs activation and improve the local antitumor immune response. This formulation was selected based on its elastic and mucoadhesive properties obtained thanks to rheological studies. More importantly, intratumoral residence time of the labelled gel and protein were evidenced by means of MRI and non invasive in vivo optical imaging. Then, the efficacy of the combination of immunomodulators loaded thermogel was demonstated in vitro and in vivo. The selected thermogel exhibits rheological properties which confer a good elasticity and increased residence time of the immunostimulatory agents in the tumor, thus increasing the recruitment of DCs and T cytotoxic CD8+ lymphocytes.

Local immunomodulation combined to radiofrequency ablation results in a complete cure of local and distant colorectal carcinoma.

Radiofrequency ablation (RFA) of colorectal liver metastases activates a specific T-cell response that is ineffective in avoiding recurrence. Recently, local immunomodulation garnered interests as a way to improve the immune response. We were interested in improving the RFA immune response priming to propose a curative treatment of colorectal cancer (CRC) based on antitumor immunity. First, we demonstrated that the RFA did not increase the tumor infiltrating lymphocytes in secondary distant tumors of patients and in mice model and could not avoid relapse. Remarkably, RFA and in situ immunomodulation with GM-CSF-BCG hydrogel induced complete cure of microscopic secondary lesions in mice, related to a strong specific immune response. Then, we demonstrated that the immune escape of large secondary lesions was reversed by addition of the systemic PD-1 blockade to the in situ immunomodulation. The lack of an effective distant immune response in patients treated with RFA confirmed the relevance of this new combination strategy. Increasing the in situ priming response of radiofrequency ablation provides effective adjuvants to induce an abscopal effect. In the case of large lesions, synergy between PD1 blockade inhibitor, ineffective alone or after single RFA, with in situ immunomodulation, could lead to reconsideration of the use of checkpoint inhibition in metastatic MSS CRC.

Postoperative morbidity and mortality for malignant colon obstruction: the American College of Surgeon calculator reliability.

BACKGROUND: The American College of surgical risk calculator (SRC) score has never been validated specifically for surgery in emergency. The objective was to evaluate the reliability of this calculator in patients with malignant colon obstruction. MATERIALS AND METHODS: We retrospectively have analyzed the morbidity and mortality observed in operated patients. Risk factors for postoperative morbidity and mortality were analyzed by logistic regression model. We have compared the morbidity and mortality estimated by the SRC score with that observed using the Brier Score (BS). A BS of 0 indicated perfect prediction, whereas a BS of 1 indicated the poorest prediction. RESULTS: Sixty-nine patients aged 75 y (41-93) have been operated on emergency from November 2001 to August 2015. The tumor was localized in the sigmoid in 33 cases (48%), in the splenic flexure in nine cases (13%), and in the right colon in 17 cases (25%). The surgical procedures were as follows: right colectomy with anastomosis (29%), diverting proximal iliac colostomy (23%), and subtotal colectomy with anastomosis (19%). The SRC score indicated a good predictivity for mortality (9.8% predicted versus 8.7% observed, BS = 0.058), for morbidity (33.4% versus 40.6%, BS = 0.209), and for serious morbidity (25.5% versus 17.4%, BS = 0.131). In multivariate analysis, SRC was an independent risk factor for mortality (P = 0.030 odds ratio [OR] = 1.07 [1.01-1.15]) and morbidity (P = 0.001 OR = 1.16 [1.08-1.27]). CONCLUSIONS: SRC score is a reliable tool for assessing the morbidity and mortality of obstructive colon cancer and could help with adapting the surgical gesture to the risks predicted.

Radiofrequency ablation for colorectal cancer liver metastases initially greater than 25 mm but downsized by neo-adjuvant chemotherapy is associated with increased rate of local tumor progression.

BACKGROUND: Radiofrequency ablation (RFA) is a valid treatment for liver metastases from colorectal cancer (CRLM) smaller than 25 mm and unsuitable for surgical resection. Tumor size is predictive for local tumor progression (LTP). The aim of this study was to evaluate whether RFA is indicated for lesions >25 mm at presentation but <25 mm after chemotherapy. METHOD: Patients who underwent RFA for CRLM after chemotherapy (January 2004-December 2012) were reviewed. Metastases were classified according to their size. Group 1: ≤25 mm before and after chemotherapy. Group 2A: >25 mm before but ≤25 mm after chemotherapy. Group 2B: >25 mm before and after chemotherapy. RESULTS: 133 CRLM were ablated in 83 patients (median follow-up 56 months). At 1-year, the LTP rate was higher in group 2A than in group 1 (32% vs. 16%, p ≤ 0.001). The highest rate of 1-year LTP was 64% in group 2B. Time to LTP (TLTP) was shorter in group 2A than in group 1 (HR: 2.89; 95% CI [1.04-8.01]; p = 0.004). Following multivariate analysis, the group type was the only predictive factor for TLTP (p < 0.001). CONCLUSIONS: RFA is not the optimal treatment for CRLM > 25 mm at presentation.

Sigmoid resection with primary anastomosis and ileostomy versus laparoscopic lavage in purulent peritonitis from perforated diverticulitis: outcome analysis in a prospective cohort of 40 consecutive patients.

PURPOSE: This prospective study aimed to compare outcomes after laparoscopic peritoneal lavage (LPL) and sigmoid resection with primary colorectal anastomosis (RPA). METHODS: From June 2010 to June 2015, 40 patients presenting with Hinchey III peritonitis from perforated diverticulitis underwent LPL or RPA. Patients with Hinchey II or IV peritonitis and patients who underwent an upfront Hartmann procedure were excluded. Primary endpoint was overall 30-day or in-hospital postoperative morbidity after surgical treatment of peritonitis. RESULTS: Twenty-five patients underwent RPA and 15 LPL. Overall postoperative morbidity and mortality rates were not significantly different after RPA and LPL (40 vs 67 %, p = 0.19; 4 vs 6.7 %, p = 1, respectively). Intra-abdominal morbidity and reoperation rates were significantly higher after LPL compared to RPA (53 vs 12 %, p < 0.01; 40 vs 4 %, p = 0.02, respectively). Multivariate analysis showed that LPL (p = 0.028, HR = 18.936, CI 95 % = 1.369-261.886) was associated with an increased risk of postoperative intra-abdominal septic morbidity. Among 6 patients who underwent reoperation after LPL, 4 had a Hartmann procedure. All surviving patients who had a procedure requiring stoma creation underwent stoma reversal after a median delay of 92 days after LPL and 72 days after RPA (p = 0.07). CONCLUSION: LPL for perforated diverticulitis is associated with a high risk of inadequate intra-abdominal sepsis control requiring a Hartmann procedure in up to 25 % of patients. RPA appears to be safer and more effective. It may represent the best option in this context.

Management of patients over 80 years of age treated with resection for localised colon cancer: results from a French referral centre.

BACKGROUND: Few data are available on management of very elderly colon cancer patients, especially concerning the parameters of therapeutic decisions and the role of geriatricians. METHODS: We retrospectively reviewed the charts of patients over 80 years of age who underwent surgery for a localised colon cancer in a French academic hospital. RESULTS: A total of 176 patients underwent surgery (postoperative morbidity and mortality rates: 25% and 6.7%). Adjuvant chemotherapy was discussed at a multidisciplinary team meeting for 91% of stage III patients, but only 13.5% of them were treated. Twenty-five patients relapsed: 19 were discussed at the multidisciplinary meeting and 16 were treated (5 had a metastasectomy). Despite their increase with time, geriatric assessments were infrequent, 17% (33% after 2006), and had no impact on postoperative morbi-mortality. Median overall survival and recurrence-free survival were 65.3 months and 65.1 months, respectively. Age, emergency surgery, and Charlson comorbidity index were independent prognostic factors. CONCLUSION: Selected elderly colon cancer patients have significant access to surgery. However, postoperative morbi-mortality rates remain high and adjuvant chemotherapy rarely prescribed. Perioperative geriatric assessment, especially before surgery, should be routinely proposed to these patients to evaluate its impact on postoperative morbi-mortality and prescription of adjuvant treatment.

Linear quantification of lymphoid infiltration of the tumor margin: a reproducible method, developed with colorectal cancer tissues, for assessing a highly variable prognostic factor.

BACKGROUND: Lymphoid infiltration is a prognostic marker in solid tumors, such as colorectal, breast and lung carcinomas. However, lymphoid infiltration is heterogeneous and the reproducibility of quantification based on single counts within a tumor is very low. We aimed to develop a reproducible method for evaluating lymphoid infiltration in tumors. METHODS: Virtual slides were obtained from tissue sections from the localized colorectal carcinomas of 117 patients, stained for CD3 and CD45R0. We assessed the variation of lymphoid cell density by automatic counts in 1 mm-wide, 5 µm-long segments of the invasive front, along an axis 4 mm in length running perpendicular to the invasive front of the tumor. RESULTS: We plotted curves of the variation of lymphocyte density across the tumor front. Three distinct patterns emerged from this linear quantification of lymphocyte (LQLI). In pattern 1, there was a high density of lymphocytes within the tumor. In pattern 2, lymphocyte density peaked close to the invasive margin. In pattern 3, lymphocytes were diffusely distributed, at low density. It was possible to classify all the tumors studied, and interobserver reproducibility was excellent (kappa =0.9). By contrast, single counts of CD3+ cells on tissue microarrays were highly variable for a given LQLI pattern, confirming the heterogeneity of lymphoid infiltration within individual tumors. In univariate analysis, all pathologic features (stage, metastatic lymph node ratio (LNR), vascular embolism, perineural invasion), CD3+ cell density, LQLI patterns for CD3+ and CD45R0+ cells) were found to have a significant effect on disease-free survival (DFS). In multivariate analysis, only the LQLI pattern for CD3+ cells (HR: 6.02; 95% CI: 2.74-13.18) and metastatic lymph node ratio (HR: 6.14; 95% CI: 2.32-16.2) were associated with DFS. CONCLUSION: LQLI is an automated, reproducible method for the assessment of lymphoid infiltration. However, validation of its prognostic value in larger series is required before its introduction into routine practice for prognostic evaluation in patients with colorectal carcinomas. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9861460717895880.

Evaluation of predictive models in daily practice for the identification of patients with Lynch syndrome.

The optimal strategy for identifying patients with Lynch syndrome among patients with newly diagnosed colorectal cancer (CRC) is still debated. Several predictive models (e.g., MMRpredict, PREMM1,2 and MMRpro) combining personal and familial data have recently been developed to quantify the risk that a given patient with CRC carries a Lynch syndrome-causing mutation. Their clinical applicability to patients with CRC from the general population requires evaluation. We studied a consecutive series of 214 patients with newly diagnosed CRC characterized for tumor microsatellite instability (MSI), somatic BRAF mutation, MLH1 promoter methylation and mismatch repair (MMR) gene germline mutation status. The performances of the models for identifying MMR mutation carriers (8/214, 3.7%) were evaluated and compared to the revised Bethesda guidelines and a molecular strategy based on MSI testing in all patients followed by the exclusion of MSI-positive sporadic cases from mutational testing by screening for BRAF mutation and MLH1 promoter methylation. The sensitivities of the three models, at the lowest thresholds proposed, were identical (75%), with similar numbers of probands eligible for further MSI testing (almost half the patients). In our dataset, the prediction models gave no better discrimination than the revised Bethesda guidelines. Both approaches failed to identify two of the eight mutation carriers (the same two patients, aged 67 and 81 years, both with no family history). Thus, like the revised Bethesda guidelines, predictive models did not identify all patients with Lynch syndrome in our series of consecutive CRC. Our results support systematic screening for MMR deficiency in all new CRC cases.

Improved retroviral suicide gene transfer in colon cancer cell lines after cell synchronization with methotrexate.

BACKGROUND: Cancer gene therapy by retroviral vectors is mainly limited by the level of transduction. Retroviral gene transfer requires target cell division. Cell synchronization, obtained by drugs inducing a reversible inhibition of DNA synthesis, could therefore be proposed to precondition target cells to retroviral gene transfer. We tested whether drug-mediated cell synchronization could enhance the transfer efficiency of a retroviral-mediated gene encoding herpes simplex virus thymidine kinase (HSV-tk) in two colon cancer cell lines, DHDK12 and HT29. METHODS: Synchronization was induced by methotrexate (MTX), aracytin (ara-C) or aphidicolin. Gene transfer efficiency was assessed by the level of HSV-TK expression. Transduced cells were driven by ganciclovir (GCV) towards apoptosis that was assessed using annexin V labeling by quantitative flow cytometry. RESULTS: DHDK12 and HT29 cells were synchronized in S phase with MTX but not ara-C or aphidicolin. In synchronized DHDK12 and HT29 cells, the HSV-TK transduction rates were 2 and 1.5-fold higher than those obtained in control cells, respectively. Furthermore, the rate of apoptosis was increased two-fold in MTX-treated DHDK12 cells after treatment with GCV. CONCLUSIONS: Our findings indicate that MTX-mediated synchronization of target cells allowed a significant improvement of retroviral HSV-tk gene transfer, resulting in an increased cell apoptosis in response to GCV. Pharmacological control of cell cycle may thus be a useful strategy to optimize the efficiency of retroviral-mediated cancer gene therapy.

Anatomical bases of prolonged ilio-inguinal-hypogastric regional anesthesia.

Although anesthesia and post-operative analgesia are associated with specific morbidity, regional anesthesia is not systematically given during groin hernia surgery. The goals of this work were to determine the anatomical bases of safe ilio-inguinal (II)-hypogastric anesthesia that can be prolonged into the post-operative period and to validate this technique on anatomical preparations and in clinical situations. We studied the courses of the ilio-hypogastric (IH) and II nerves in 33 halves of 20 embalmed adult cadavers. The intermediate portion of the IH and II nerves, located between the transverse and the internal oblique muscles, were found to be suitable for a simultaneous block with a single injection. We assessed the feasibility of injecting a percutaneous infiltration into this space by injecting a dye before dissection. In 75% of cases, we observed percutaneous coloring of the nerves, confirming that this site was suitable. To guide the infiltration, the points where the nerves passed through the transverse and the internal oblique muscles were located from the iliac crest and anterior and superior iliac spine, respectively. The nerve trunks were grouped for over 5 cm in a cell-fat layer running between these two deep muscles. It was possible to position a micro-catheter in this anatomical space to allow repeated injections. The results of this anatomical study were used to modify the technique so that it could be used to provide regional anesthesia in five patients operated on for hernia. Post-operative pain was very effectively controlled in four cases with no complications.

A common hepatic artery passing in front of the portal vein.

A variation in liver vascularization was discovered in a 50-year-old man. A single common hepatic artery was found to be responsible for vascularization of the entire liver. This artery was unusual in that it formed the first branch of the superior mesenteric artery, crossing the portal trunk shortly after its origin, and passed in front of the portal vein to reach the hilum of the liver, where it divided into a right and a left branch. This artery was a true common hepatic artery because a gastroduodenal artery emerged from it 2 cm after its origin. A common hepatic artery originating from the mesenteric artery and passing in front of the portal vein has never been described before. The patient had a second anatomical variation: the left gastric artery and the splenic artery arose directly from the aorta, without celiac trunk separation. This observation confirms the importance of carrying out a precise vascular assessment before all types of hepatic or pancreatic surgery, to identify possible variations in the number or trajectory of hepatic arteries.