ICG fluorescence imaging in colorectal surgery: a snapshot from the ICRAL study group

Background

Fluorescence-guided visualization is a recently proposed technology in colorectal surgery. Possible uses include evaluating perfusion, navigating lymph nodes and searching for hepatic metastases and peritoneal spread. Despite the absence of high-level evidence, this technique has gained considerable popularity among colorectal surgeons due to its significant reliability, safety, ease of use and relatively low cost. However, the actual use of this technique in daily clinical practice has not been reported to date.

Methods

This survey was conducted on April 2020 among 44 centers dealing with colorectal diseases and participating in the Italian ColoRectal Anastomotic Leakage (iCral) study group. Surgeons were approximately equally divided based on geographical criteria from multiple Italian regions, with a large proportion based in public (89.1%) and nonacademic (75.7%) centers. They were invited to answer an online survey to snapshot their current behaviors regarding the use of fluorescence-guided visualization in colorectal surgery. Questions regarding technological availability, indications and techniques, personal approaches and feelings were collected in a 23-item questionnaire.

Results

Questionnaire replies were received from 37 institutions and partially answered by 8, as this latter group of centers do not implement fluorescence technology (21.6%). Out of the remaining 29 centers (78,4%), fluorescence is utilized in all laparoscopic colorectal resections by 72.4% of surgeons and only for selected cases by the remaining 27.6%, while 62.1% of respondents do not use fluorescence in open surgery (unless the perfusion is macroscopically uncertain with the naked eye, in which case 41.4% of them do). The survey also suggests that there is no agreement on dilution, dosing and timing, as many different practices are adopted based on personal judgment. Only approximately half of the surgeons reported a reduced leak rate with fluorescence perfusion assessment, but 65.5% of them strongly believe that this technique will become a minimum requirement for colorectal surgery in the future.

Conclusion

The survey confirms that fluorescence is becoming a widely used technique in colorectal surgery. However, both the indications and methods still vary considerably; furthermore, the surgeons' perceptions of the results are insufficient to consider this technology essential. This survey emphasizes the need for further research to reach recommendations based on solid scientific evidence.

Colorectal Cancer Surgery During the COVID-19 Pandemic: A Single Center Experience

BACKGROUND/AIM

A notable re-allocation of healthcare resources and specific clinical and organizational measures have been required to prevent COVID-19 infection among hospitalized patients and healthcare workers.

PATIENTS AND METHODS

From March 9th to May 9th 2020 we performed colorectal cancer elective surgery on 25 patients: a pre-hospital screening was carried out in order to avoid hospitalization of patients suspected of COVID-19 infection.

RESULTS

All patients (median age=76 years; range=37-88 years) were considered suitable for admission after telephone triage; the median interval between primary diagnosis and hospital admission was 23.1 days (range=1-55 days). The median hospitalization was 7.8 days (range=4-18 days). One COVID-19-associated death was reported.

CONCLUSION

Our experience demonstrates that safe colorectal cancer elective surgery can be performed during the pandemic COVID-19. Further consensus and guidelines to prevent diffusion of pandemic diseases among hospitalized patients and healthcare workers still need to be implemented.

Comprehensive geriatric assessment in older adults with cancer: Recommendations by the Italian Society of Geriatrics and Gerontology (SIGG)

INTRODUCTION

Optimizing the approach to older adults with cancer is now a priority given the increasing frequency of new cancer diagnoses that are made in the older population. The comprehensive geriatric assessment (CGA) represents the gold-standard for (1) defining prognosis and ability to withstand cancer treatments, (2) exploring the multiple aspects that define the complexity of frail older persons, and (3) designing person-tailored interventions.

MATERIALS AND METHODS

In this document, based on a comprehensive revision of the literature, the Italian Society for Geriatrics and Gerontology proposes a CGA model (ONCOGER CGA) to be adopted by oncology centers for their routine approach to older patients with cancer.

RESULTS AND DISCUSSION

A widespread use of this standardized CGA format will facilitate comparisons across institutions, promote studies based on a multidimensional patient assessment, and foster the inclusion of geriatric endpoints in oncological clinical trials. Furthermore, we predict that the use of a standardized CGA approach will increase the integration of geriatricians into oncology care teams with the final result of improving therapeutic choices and clinical outcomes.

Colorectal surgery in Italy during the Covid19 outbreak: a survey from the iCral study group

BACKGROUND

The COVID19 pandemic had a deep impact on healthcare facilities in Italy, with profound reorganization of surgical activities. The Italian ColoRectal Anastomotic Leakage (iCral) study group collecting 43 Italian surgical centers experienced in colorectal surgery from multiple regions performed a quick survey to make a snapshot of the current situation.

METHODS

A 25-items questionnaire was sent to the 43 principal investigators of the iCral study group, with questions regarding qualitative and quantitative aspects of the surgical activity before and after the COVID19 outbreak.

RESULTS

Two-thirds of the centers were involved in the treatment of COVID19 cases. Intensive care units (ICU) beds were partially or totally reallocated for the treatment of COVID19 cases in 72% of the hospitals. Elective colorectal surgery for malignancy was stopped or delayed in nearly 30% of the centers, with less than 20% of them still scheduling elective colorectal resections for frail and comorbid patients needing postoperative ICU care. A significant reduction of the number of colorectal resections during the time span from January to March 2020 was recorded, with significant delay in treatment in more than 50% of the centers.

DISCUSSION

Our survey confirms that COVID19 outbreak is severely affecting the activity of colorectal surgery centers participating to iCral study group. This could impact the activity of surgical centers for many months after the end of the emergency.

The GPS for surgery: A user-centered evaluation of a navigation system for laparoscopic surgery

BACKGROUND

Unsafe surgical care has emerged as a significant public health concern, motivated by a high percentage of major complications happening during surgery, attributed to surgeons' skills and experience, and determined to be preventable.

METHODS

This article presents APSurg, an Abdominal Positioning Surgical system designed to improve awareness and safety during laparoscopic surgery. The proposed system behaves like a GPS, offering an additional dynamic virtual reality view of the surgical field.

RESULTS

This work presents an evaluation study in terms of accuracy, effectiveness, and usability. Tests were conducted performing a localization task on an abdomen phantom in a simulated scenario. Results show a navigation accuracy below 5 mm. The task execution time was reduced by a 15% and the performed incision dimension was reduced by a 46%, with respect to a standard setup. A custom questionnaire showed a significant positive impact in exploiting APSurg during the surgical task execution.

Mid-transverse colon cancer and extended versus transverse colectomy: Results of the Italian society of surgical oncology colorectal cancer network (SICO CCN) multicenter collaborative study

INTRODUCTION

Transverse colon cancer (TCC) is poorly studied, and TCC cases are often excluded from large prospective randomized trials because of their complexity and their potentially high complication rate. The best surgical approach for TCC has yet to be established. The aim of this large retrospective multicenter Italian series is to investigate the advantages and disadvantages of both hemicolectomy and transverse colectomy in order to identify the best surgical approach.

MATERIALS AND METHODS

This was a retrospective cohort study of patients with mid-transverse colon cancer treated with a segmental colon resection or an extended hemicolectomy (right or left) between 2006 and 2016 in 28 high-volume (more than 70 procedures/year) Italian referral centers for colorectal surgery.

RESULTS

The study included 1529 patients, 388 of whom underwent a segmental resection while 1141 underwent an extended resection. A higher number of complications has been reported in the segmental group than in the extended group (30.1% versus 23.6%; p 0.010). In 42 cases the main complication was the anastomotic leak (4.4% versus 2.2%; p 0.020). Recovery outcomes also showed statistical differences: time to first flatus (p 0.014), time to first mobilization (p 0.040), and overall hospital stay (p < 0.001) were significantly shorter in the extended group. Even if overall survival were similar between the groups (95.1% versus 97%; p 0.384), 3-year disease-free survival worsened after segmental resection (78.1% versus 86.2%; p 0.001).

CONCLUSIONS

According to our results, an extended right colon resection for TCC seems to be surgically safer and more oncologically valid.

A two-step surgery and a multidisciplinary approach in a centenarian patient with an acute presentation of right colon cancer

Background

As surgery remains the cornerstone of colorectal cancer (CRC) treatment, the number of older patients presented for colorectal resection is rapidly increasing. Nevertheless, the choice to operate an oldest-old patient still remain challenging and requires a careful assessment of risk to benefit ratio in order to guarantee appropriate surgical strategies and perioperative management.

Case presentation

A centenarian patient, acutely admitted to the emergency department, was diagnosed with an ileus caused by stenosing ascending colon cancer with abnormal distension of the right colon at high risk of perforation. Facing with this complex clinical scenario, a lateral decompressive cecostomy as alternative surgical procedure, was performed in local anesthesia in order to avoid the stressful event of an emergency surgery. Thereafter, the patient was admitted to the surgical ward and followed by a geriatrician who performed a comprehensive geriatric assessment (CGA) and daily clinical evaluations. This integrated plan of care was mainly focused on rehabilitation, nutritional interventions and therapeutic reconciliation, maximizing patient’s clinical conditions and performance status. Then, the second surgical step, the radical colon surgery with curative intent and bowel continuity reestablishment was performed, demonstrating to be feasible and safety also in a very advanced age patient in term of prolonged survival and preservation of an adequate quality of life.

Conclusions

This is the first case-report that illustrates a successful two step surgery for CRC in a centenarian patient thanks to a multidisciplinary based approach, overwhelming the mere concept of chronological age.

Evaluation of Glycosylated PTGS2 in Colorectal Cancer for NSAIDS-Based Adjuvant Therapy

Observational/retrospective studies indicate that prostaglandin-endoperoxide synthase-2 (PTGS2) inhibitors could positively affect colorectal cancer (CRC) patients' survival after diagnosis. To obtain an acceptable cost/benefit balance, the inclusion of PTGS2 inhibitors in the adjuvant setting needs a selective criterion. We quantified the 72 kDa, CRC-associated, glycosylated form of PTGS2 in 100 frozen CRC specimens and evaluated PTGS2 localization by IHC in the same tumors, scoring tumor epithelial-derived and stroma-derived fractions. We also investigated the involvement of interleukin-1 beta (IL1β) in PTGS2 induction, both in vitro and in CRC lysates. Finally, we used overall survival (OS) as a criterion for patient selection. Glycosylated PTGS2 can be quantified with high sensibility in tissue lysates, but the expression in both tumor and stromal cells limits its use for predictive purposes. Immunohistochemistry (IHC) analysis indicates that stromal PTGS2 expression could exert a protective role on patient OS. Stromal PTGS2 was prevalently expressed by cancer-associated fibroblasts exerting a barrier function near the gut lumen, and it apparently favored the antitumor M1 macrophage population. IL1β was directly linked to gPTGS2 expression both in vitro and in tumors, but its activity was apparently prevalent on the stromal cell population. We suggest that stromal PTGS2 could exert a positive effect on patients OS when expressed in the luminal area of the tumor.

Development of a long non-coding RNA signature for prediction of response to neoadjuvant chemoradiotherapy in locally advanced rectal adenocarcinoma

Standard treatment for locally advanced rectal adenocarcinoma (LARC) includes a combination of chemotherapy with pyrimidine analogues, such as capecitabine, and radiation therapy, followed by surgery. Currently no clinically useful genomic predictors of benefit from neoadjuvant chemoradiotherapy (nCRT) exist for LARC. In this study we assessed the expression of 8,127 long noncoding RNAs (lncRNAs), poorly studied in LARC, to infer their ability in classifying patients’ pathological complete response (pCR). We collected and analyzed, using lncRNA-specific Agilent microarrays a consecutive series of 61 LARC cases undergoing nCRT. Potential lncRNA predictors in responders and non-responders to nCRT were identified with LASSO regression, and a model was optimized using k-fold cross-validation after selection of the three most informative lncRNA. 11 lncRNAs were differentially expressed with false discovery rate < 0.01 between responders and non-responders to NACT. We identified lnc-KLF7-1, lnc-MAB21L2-1, and LINC00324 as the most promising variable subset for classification building. Overall sensitivity and specificity were 0.91 and 0.94 respectively, with an AUC of our ROC curve = 0.93. Our study shows for the first time that lncRNAs can accurately predict response in LARC undergoing nCRT. Our three-lncRNA based signature must be independently validated and further analyses must be conducted to fully understand the biological role of the identified signature, but our results suggest lncRNAs may be an ideal biomarker for response prediction in the studied setting.

Development and Validation of a Homemade, Low-Cost Laparoscopic Simulator for Resident Surgeons (LABOT)

Several studies have demonstrated that training with a laparoscopic simulator improves laparoscopic technical skills. We describe how to build a homemade, low-cost laparoscopic training simulator (LABOT) and its validation as a training instrument. First, sixty surgeons filled out a survey characterized by 12 closed-answer questions about realism, ergonomics, and usefulness for surgical training (global scores ranged from 1—very insufficient to 5—very good). The results of the questionnaires showed a mean (±SD) rating score of 4.18 ± 0.65 for all users. Then, 15 students (group S) and 15 residents (group R) completed 3 different tasks (T1, T2, T3), which were repeated twice to evaluate the execution time and the number of users’ procedural errors. For T1, the R group had a lower mean execution time and a lower rate of procedural errors than the S group; for T2, the R and S groups had a similar mean execution time, but the R group had a lower rate of errors; and for T3, the R and S groups had a similar mean execution time and rate of errors. On a second attempt, all the participants tended to improve their results in doing these surgical tasks; nevertheless, after subgroup analysis of the T1 results, the S group had a better improvement of both parameters. Our laparoscopic simulator is simple to build, low-cost, easy to use, and seems to be a suitable resource for improving laparoscopic skills. In the future, further studies should evaluate the potential of this laparoscopic box on long-term surgical training with more complex tasks and simulation attempts.

Lymph node number, surface area and lymph node ratio are important prognostic indicators in neoadjuvant chemoradiotherapy treated rectal cancer

AIMS

Neoadjuvant chemoradiotherapy (neoCRT) is recommended for locally advanced rectal cancer (RC), however, this often makes lymph node (LN) search trying. The aim of this study was to evaluate, in a large retrospective, monocentric, series of post-neoCRT-RC patients, the importance of LN number, ratio and surface area in predicting metastases, overall survival (OS) and disease free survival (DFS).

METHODS

104 patients with RC underwent total mesorectal excision, after standard neoCRT. All resected specimens were examined according to a standardised sampling/histopathological protocol. The following data regarding LNs were collected: total numbers; number with metastases; LNratio (metastatic/total); maximum diameter; surface area.

RESULTS

A statistically significant association was found between LN number and DFS (p=0.0473). Finding ≤9 or >20 LNs correlated with worse prognosis compared with 10-20 (p value=0.049). LNratio (>0.2) was strongly associated with shorter DFS (HR=13.36; p value <0.0001) and OS (HR=26.06; p value <0.0001). Poor outcome, for DFS (HR=2.17, p value =0.0416) and OS (HR=1.18, p value =0.0025), was associated with increasing LN surface area. LNratio was independently associated with DFS at multivariate analysis (p value <0.0001).

CONCLUSIONS

LN number, LNratio and LN surface area are important prognostic factors in neoCRT-RC and in particular finding ≤9 or >20 LNs is prognostically adverse.

Clinico-pathological associations and concomitant mutations of the RAS/RAF pathway in metastatic colorectal cancer

BACKGROUND

Over the past few years, next-generation sequencing (NGS) has become reliable and cost-effective, and its use in clinical practice has become a reality. A relevant role for NGS is the prediction of response to anti-EGFR agents in metastatic colorectal cancer (mCRC), where multiple exons from KRAS, NRAS, and BRAF must be sequenced simultaneously.

METHODS

We optimized a 14-amplicon NGS panel to assess, in a consecutive cohort of 219 patients affected by mCRC, the presence and clinico-pathological associations of mutations in the KRAS, NRAS, BRAF, and PIK3CA genes from formalin-fixed, paraffin-embedded specimens collected for diagnostics and research at the time of diagnosis.

RESULTS

We observed a statistically significant association of RAS mutations with sex, young age, and tumor site. We demonstrated that concomitant mutations in the RAS/RAF pathway are not infrequent in mCRC, and as anticipated by whole-genome studies, RAS and PIK3CA tend to be concurrently mutated. We corroborated the association of BRAF mutations in right mCRC tumors with microsatellite instability. We established tumor side as prognostic parameter independently of mutational status.

CONCLUSIONS

To our knowledge, this is the first monocentric, consecutively accrued clinical mCRC cancer cohort tested by NGS in a real-world context for KRAS, NRAS, BRAF, and PIK3CA. Our study has highlighted in clinical practice findings such as the concomitance of mutations in the RAS/RAF pathway, the presence of multiple mutations in single gene, the co-occurrence of RAS and PIK3CA mutations, the prognostic value of tumor side and possible associations of sex with specific mutations.

Elevated platelet count is a negative predictive and prognostic marker in locally advanced rectal cancer undergoing neoadjuvant chemoradiation: a retrospective multi-institutional study on 965 patients

BACKGROUND

In patients with locally advanced rectal cancer treated by neoadjuvant chemoradiation, pathological complete response in the surgical specimen is associated with favourable long-term oncologic outcome. Based on this observation, nonoperative management is being explored in the subset of patients with clinical complete response. Whereas, patients with poor response have a high risk of local and distant recurrence, and appear to receive no benefit from standard neoadjuvant chemoradiation. Therefore, in order to develop alternative treatment strategies for non responding patients, predictive and prognostic factors are highly needed. Accumulating clinical observations indicate that elevated platelet count is associated with poor outcome in different type of tumors. In this study we investigated the predictive and prognostic impact of elevated platelet count on pathological response and long-term oncologic outcome in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation.

METHODS

A total of 965 patients were selected from prospectively maintained databases of seven Centers within the SICO Colorectal Cancer Network. Patients were divided into two groups based on a pre-neoadjuvant chemoradiation platelet count cut-off value of 300 × 10⁹/L identified by receiver operating characteristic curve considering complete pathological response as the outcome.

RESULTS

Complete pathological response rate was lower in patients with elevated platelet count (12.8% vs. 22.1%, p = 0.001). Mean follow-up was 50.1 months. Comparing patients with elevated platelet count with patients with not elevated platelet count, 5-year overall survival was 69.5% vs.76.5% (p = 0.016), and 5-year disease free survival was 63.0% vs. 68.9% (p = 0.019). Local recurrence rate was higher in patients with elevated platelet count (11.1% vs. 5.3%, p = 0.001), as higher was the occurrence of distant metastasis (23.9% vs. 16.4%, p = 0.007). At multivariate analysis of potential prognostic factors EPC was independently associated with worse overall survival (HR 1.40, 95% CI 1.06-1.86), and disease free survival (HR 1.37, 95% CI 1.07-1.76).

CONCLUSIONS

In locally advanced rectal cancer elevated platelet count before neoadjuvant chemoradiation is a negative predictive and prognostic factor which might help to identify subsets of patients with more aggressive tumors to be proposed for alternative therapeutic strategies.

Predictive values of two frailty screening tools in older patients with solid cancer: a comparison of SAOP2 and G8

Objectives

Comprehensive Geriatric Assessment (CGA), the gold standard for detecting frailty in elderly cancer patients, is time-consuming and hard to apply in routine clinical practice. Here we compared the performance of two screening tools for frailty, G8 and SAOP2 for their accuracy in identifying vulnerable patients.

Material and Methods

We tested G8 and SAOP2 in 282 patients aged 65 or older with a diagnosis of solid cancer and candidate to undergo surgical, medical and/or radiotherapy treatment. CGA, including functional and cognitive status, depression, nutrition, comorbidity, social status and quality of life was used as reference. ROC curves were used to compare two screening tools.

Results

Mean patient age was 79 years and 54% were female. Colorectal and breast cancer were the most common types cancer (49% and 24%). Impaired CGA, G8, and SAOP2 were found in 62%, 89%, and 94% of the patients, respectively. SAOP2 had a better sensitivity (AUC 0.85, p<0.032) than G8 (AUC 0.79), with higher performance in breast cancer patients (AUC 0.93) and in patients aged 70-80 years (AUC 0.87).

Conclusions

G8 and SAOP2 both showed good screening capacity for frailty in the cancer patient population we examined with SAOP2 showing a slightly better performance than G8.

Effects of CTLA4-Ig treatment on circulating fibrocytes and skin fibroblasts from the same systemic sclerosis patients: an in vitro assay

Background

Systemic sclerosis (SSc) is characterized by vasculopathy and progressive fibrosis. CTLA4-Ig (abatacept) is able to interact with the cell surface costimulatory molecule CD86 and downregulate the target cell. The aim of this study was to evaluate the in-vitro effects of CTLA4-Ig treatment on circulating fibrocytes and skin fibroblasts isolated from the same SSc patient.

Methods

Circulating fibrocytes and skin fibroblasts were obtained from eight SSc patients with “limited” cutaneous involvement and from four healthy subjects (HSs). Samples were analyzed by fluorescence-activated cell sorter analysis (FACS) at baseline (T0) and after 8 days of culture (T8) for CD45, collagen type I (COL I), CXCR4, CD14, CD86, and HLA-DRII expression. Circulating fibrocytes were treated for 3 h and skin fibroblasts for 24/48 h with CTLA4-Ig (10, 50, 100, 500 μg/ml). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for CD86, COL I, FN, TGFβ, αSMA, S100A4, CXCR2, CXCR4, CD11a, and Western blotting was performed for COL I and FN.

Results

Using qRT-PCR, the T8-cultured SSc circulating fibrocytes which had not been treated with CTLA4-Ig showed higher gene expression for CD86, αSMA, S100A4, TGFβ, and COL I compared with HS circulating fibrocytes. Interestingly, αSMA/COL I gene expression was significantly lower only in the SSc circulating fibrocytes treated with CTLA4-Ig for 3 h (p < 0.01, p < 0.05). On the contrary, no effects were observed for either SSc or HS skin fibroblasts after CTLA4-Ig treatment. COL I and FN protein expression was unchanged in both SSc and HS skin fibroblasts by Western blot.

Conclusions

Circulating fibrocytes seem to be more responsive to CTLA4-Ig treatment than skin fibroblasts from the same SSc patient, likely due to their higher expression of CD86. CTLA4-Ig treatment might downregulate the fibrotic process in SSc patients by downregulating the fibrocytes, circulating progenitor cells.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1652-6) contains supplementary material, which is available to authorized users.

Abstract 2465: Long non-coding RNA ZNF-366-6 predicts lack of response to neoadjuvant chemoradiotherapy in locally advanced rectal adenocarcinoma and presents meaningful biological associations with potential coding cancer driver transcripts related to gastrointestinal cancer pathways

Standard treatment for clinical stage II/III rectal adenocarcinoma (READ) includes a combination of chemotherapy with pyrimidine analogues, such as capecitabine, and radiation therapy, followed by surgery after 6 to 12 weeks. Currently no predictors of benefit from neoadjuvant chemoradiotherapy (NACT) exist, and transcriptomic studies, prevalently focused on coding transcripts or miRNAs have so far failed to find clinically useful gene signatures. In the present analysis we assessed the expression levels of 8,127 long non-coding RNAs (lncRNAs), poorly studied in the context of READ, to infer whether they could stratify pre-treatment READ samples according to patients' pathological complete response (pCR).

Methods: We collected and analysed with Agilent SurePrint G3 Human v2 8x60K microarrays, a consecutive series of 49 specimens from READ patients undergoing NACT with a combination of capecitabine (825 mg/m2) and radiation (50.4 Gy) cycles for 6 weeks. We performed a regularized variable selection regression (“glmnet” R package) to identify potential lncRNAs predicting pCR. We then analysed, with a bivariate correlation, the top lncRNAs predictors with the expression of 20,560 coding transcripts represented in the microarrays we used, and performed pathway enrichment analysis using Ingenuity® Pathway Analysis (Qiagen, Inc.).

Results: Out of 49 patients for whom we could obtain snap-frozen biopsies with complete clinical and pathological data, we analysed 30 patients, 12 with minor or absent pathological response and 18 with major or complete response to NACT. We identified a signature of 11 lncRNAs able to successfully stratify responder vs. non-responder patients. By investigating the correlation of these 11 lncRNAs with coding transcripts, we identified one of them, lnc-ZNF-366-6, presenting an unusually high correlation with more then 1136 coding genes (FDR &lt; 0.01). By gene enrichment analysis we found an enrichment in cancer-related pathways, especially alterations in solid and colon adenocarcinoma pathways (p &lt; 0.01), as well as mitochondrial dysfunction, oxidative phosphorylation and sirtuin signalling pathways (p &lt; 0.00001), defined by the positively and negatively correlated variables with lnc-ZNF-366-6. Moreover, we identified potential drivers of disease or therapeutic targets, either correlated or anti-correlated with lnc-ZNF-366-6.

Conclusions: LncRNAs have the potential to classify responder versus non-responder READ patients undergoing NACT. Lnc-ZNF-366-6 deserves further experimental validation and functional analyses to clarify its exact contribution to resistance to DNA damaging agents, such as radiation, and to inhibitors of DNA/RNA synthesis, such as capecitabine.

Citation Format: Lorenzo Ferrando, Gabriella Cirmena, A Garuti, Stefano Scabini, Federica Grillo, Luca Mastracci, Edoardo Isnaldi, Ciro Marrone, Roberto Murialdo, David Norman Brown, Roberto Fiocca, Emanuele Romairone, Alberto Ballestrero, Gabriele Zoppoli. Long non-coding RNA ZNF-366-6 predicts lack of response to neoadjuvant chemoradiotherapy in locally advanced rectal adenocarcinoma and presents meaningful biological associations with potential coding cancer driver transcripts related to gastrointestinal cancer pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2465.

Abstract 1606: Clinical routine massive parallel sequencing highlights clinicopathological associations of the RAS/RAF mutational module in metastatic colorectal cancer and reveals high frequency of concomitant RAS/RAF mutations

Background: Over the past few years, massive parallel sequencing (MPS) has become reliable and cost-effective, and its use in clinical practice has become a reality. A relevant role for MPS is the prediction of response to anti-EGFR agents in metastatic colorectal cancer (mCRC), where multiple exons from KRAS, NRAS, and BRAF must be sequenced simultaneously.Patients and methods: We optimized a 14-amplicon panel to assess by MPS the exonic regions of KRAS, NRAS, BRAF, and PIK3CA from formalin-fixed, paraffin-embedded specimen-extracted DNA. We analyzed the samples of a monocentric, prospective, consecutive cohort of patients affected by mCRC collected for diagnostic and research purposes at the time of diagnosis in our referral basin.Results: Over two years, we evaluated 219 mCRC specimens. We observed an unexpected, statistically significant association of RAS mutations with sex, young age, and tumor site (right colon). We further demonstrated, by transversal validation using digital polymerase chain reaction, that concomitant mutations in the KRAS/BRAF/NRAS module are not infrequent in mCRC. As anticipated by large, whole-genome studies, RAS and PIK3CA tended to be concurrently mutated. We corroborated associations such as the higher prevalence of BRAF mutations in right mCRCtumors, in concomitance with microsatellite instability. Finally, survival analysis showed that BRAF mutants had a shorter progression-free survival compared to KRAS/NRAS mutant patients and wildtype ones upon I line treatment.Conclusions: To our knowledge, this is the first monocentric, consecutive, prospectively accrued clinical mCRC cancer cohort tested on a clinical routine basis by MPS for KRAS, NRAS, BRAF, and PIK3CA. Our study has highlighted in clinical practice findings such as the concomitance of mutations in the RAS/RAF module, the co-occurrence of RAS and PIK3CA mutations, and possible associations of gender with specific mutations. These results need clinical follow-up in the context of treatment to assess their translational relevance.

Citation Format: Edoardo Isnaldi, Anna Garuti, Gabriella Cirmena, Stefano Scabini, Federica Grillo, Luca Mastracci, Lorenzo Ferrando, Roberto Murialdo, Maurizio Gallo, Christine Desmedt, Roberto Fiocca, Emanuele Romairone, Alberto Ballestrero, Gabriele Zoppoli. Clinical routine massive parallel sequencing highlights clinicopathological associations of the RAS/RAF mutational module in metastatic colorectal cancer and reveals high frequency of concomitant RAS/RAF mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1606.

Targeting the Epidermal Growth Factor Receptor Can Counteract the Inhibition of Natural Killer Cell Function Exerted by Colorectal Tumor-Associated Fibroblasts

Mesenchymal stromal cells (MSC) present in the tumor microenvironment [usually named tumor-associated fibroblasts (TAF)] can exert immunosuppressive effects on T and natural killer (NK) lymphocytes, favoring tumor immune escape. We have analyzed this mechanism in colorectal carcinoma (CRC) and found that co-culture of NK cells with TAF can prevent the IL-2-mediated NKG2D upregulation. This leads to the impairment of NKG2D-mediated recognition of CRC cells, sparing the NK cell activation through DNAM1 or FcγRIIIA (CD16). In situ, TAF express detectable levels of epidermal growth factor receptor (EGFR); thus, the therapeutic anti-EGFR humanized antibody cetuximab can trigger the antibody-dependent cellular cytotoxicity of TAF, through the engagement of FcγRIIIA on NK cells. Importantly, in the tumor, we found a lymphoid infiltrate containing NKp46⁺CD3^- NK cells, enriched in CD16⁺ cells. This population, sorted and cultured with IL-2, could be triggered via CD16 and via NKG2D. Of note, ex vivo NKp46⁺CD3^- cells were able to kill autologous TAF; in vivo, this might represent a control mechanism to reduce TAF-mediated regulatory effect on NK cell function. Altogether, these findings suggest that MSC from the neoplastic mucosa (TAF) of CRC patients can downregulate the immune cell recognition of CRC tumor cells. This immunosuppression can be relieved by the anti-EGFR antibody used in CRC immunotherapy.

Effects of selexipag and its active metabolite in contrasting the profibrotic myofibroblast activity in cultured scleroderma skin fibroblasts

Background

Myofibroblasts contribute to fibrosis through the overproduction of extracellular matrix (ECM) proteins, primarily type I collagen (COL-1) and fibronectin (FN), a process which is mediated in systemic sclerosis (SSc) by the activation of fibrogenic intracellular signaling transduction molecules, including extracellular signal-regulated kinases 1 and 2 (Erk1/2) and protein kinase B (Akt). Selexipag is a prostacyclin receptor agonist synthesized for the treatment of pulmonary arterial hypertension. The study investigated the possibility for selexipag and its active metabolite (ACT-333679) to downregulate the profibrotic activity in primary cultures of SSc fibroblasts/myofibroblasts and the fibrogenic signaling molecules involved.

Methods

Fibroblasts from skin biopsies obtained with Ethics Committee (EC) approval from patients with SSc, after giving signed informed consent, were cultured until the 3^rd culture passage and then either maintained in normal growth medium (untreated cells) or independently treated with different concentrations of selexipag (from 30 μM to 0.3 μM) or ACT-333679 (from 10 μM to 0.1 μM) for 48 h. Protein and gene expressions of α-smooth muscle actin (α-SMA), fibroblast specific protein-1 (S100A4), COL-1, and FN were investigated by western blotting and quantitative real-time PCR. Erk1/2 and Akt phosphorylation was investigated in untreated and ACT-333679-treated cells by western botting.

Results

Selexipag and ACT-333679 significantly reduced protein synthesis and gene expression of α-SMA, S100A4, and COL-1 in cultured SSc fibroblasts/myofibroblasts compared to untreated cells, whereas FN was significantly downregulated at the protein level. Interestingly, ACT-333679 significantly reduced the phosphorylation of Erk1/2 and Akt in cultured SSc fibroblasts/myofibroblasts.

Conclusions

Selexipag and mainly its active metabolite ACT-333679 were found for the first time to potentially interfere with the profibrotic activity of cultured SSc fibroblasts/myofibroblasts at least in vitro, possibly through the downregulation of fibrogenic Erk1/2 and Akt signaling molecules.