SPINK4 Expression as a Predictive Biomarker for Radiolabeled Immune Modulator Therapy in Advanced Colorectal Cancer.

To determine whether changes in apparent diffusion coefficients (ADCs) of rectal carcinoma obtained 1 week after the beginning of chemotherapy and radiation therapy (CRT) correlate with tumor histopathologic downstaging after preoperative CRT. This prospective study was approved by an institutional review board; informed consent was obtained from all patients. Thirty-seven patients (mean age, 54.7 years; 13 women, 24 men) with primary rectal carcinoma who were undergoing preoperative CRT were recruited for the study. Diffusion-weighted (DW) magnetic resonance (MR) imaging was performed with a 1.5-T MR imager in all patients before therapy, at the end of the 1st and 2nd week of therapy, and before surgery. Tumor ADCs were calculated. Linear mixed-effects modeling was applied to analyze change in ADCs and volumes following treatment. Patients were assigned to the tumor downstaged group (n = 17) or the tumor nondownstaged group (n = 20) on the basis of histopathologic examination results following surgery. Before CRT, the mean tumor ADC in the downstaged group was lower than that in the nondownstaged group (1.07 x 10(-3) mm(2)/sec +/- 0.13 [standard deviation] vs 1.19 x 10(-3) mm(2)/sec +/- 0.15, F = 6.91, P = .013). At the end of the 1st week of CRT, the mean tumor ADC increased significantly from 1.07 x 10(-3) mm(2)/sec +/- 0.13 to 1.32 x 10(-3) mm(2)/sec +/- 0.16 (F = 37.63, P <.001) in the downstaged group, but there was no significant ADC increase in the nondownstaged group (F = 1.18, P = .291). The mean percentage of tumor ADC change in the downstaged group was significantly higher than that in the nondownstaged group at each time point (F = 18.39, P < .001). Early increase of mean tumor ADC and low pretherapy mean ADC in rectal carcinoma correlate with good response to CRT. DW MR imaging is a promising noninvasive technique for helping predict and monitor early therapeutic response in patients with rectal carcinoma who are undergoing CRT.

To prospectively differentiate, at magnetic resonance (MR) imaging, patients with locally advanced nonmucinous rectal cancer who will respond to long-course chemotherapy and radiation therapy (CRT) from those who will not respond, with histopathologic results as the reference standard. Institutional review board approval for this study was obtained, and all patients provided written informed consent. High-spatial-resolution T2-weighted MR images were acquired before and 6-8 weeks after CRT in 53 patients (33 men, 20 women; mean age, 63 years; age range, 42-79 years). Patients were categorized as responders to CRT (patients with T3 cancer that converted to T2 or a lower stage, patients with T4 cancer that converted to T3 or a lower stage) or as nonresponders (patients with stable or progressive disease). At the posttreatment MR imaging examination, a decrease in signal intensity was considered to represent a morphologic response with fibrosis. Before CRT and surgery, tumor volume was calculated at MR imaging by multiplying cross-sectional area by section thickness. Tumor length was measured at MR imaging and in the histopathologic specimen. Nodal downstaging was evaluated. The relationship between pathologic response, morphologic MR imaging response, and percentage volume reduction was evaluated with the Mann-Whitney-Wilcoxon two-sample test. Morphologic response assessment with MR imaging achieved a positive predictive value (PPV) of 84.2% (32 of 38) and a negative predictive value (NPV) of 66.7% (10 of 15). Volume reduction extent (> or = 70%) was significantly different between patients in whom disease was downstaged and those in whom it was not downstaged (P = .000005) and showed additional diagnostic value, with an overall accuracy of 86.8% (46 of 53). Presurgical MR imaging and histopathologic tumor length did not show a significant difference. MR imaging accuracy for lymph node (N) stage was 86.8% (46 of 53) on the basis of morphologic criteria. After CRT, morphologic and volumetric evaluation at MR imaging had a high PPV and a low NPV for response assessment. The detection of small clusters of residual tumor cells within fibrosis remains a problem. http://radiology.rsnajnls.org/cgi/content/full/250/3/730/DC1.

Patients diagnosed with ovarian cancer face an average 5 year survival rate of 46%; low survival is driven by early and ongoing intraperitoneal dissemination and metastasis of the tumor. Among the different histotypes of ovarian cancer, ovarian clear cell carcinoma (OCCC) has a particularly poor prognosis when diagnosed in late stage, as these tumors tend to be chemoresistant, leaving no effective therapeutic options. Intraperitoneal metastasis requires cells to become anoikis resistant, where apoptosis normally induced by loss of attachment is suppressed. We seek to better understand the mechanisms involved in anoikis resistance in OCCC, which in the future could lead to new therapeutic strategies for these patients. We have found that Serine Protease Inhibitor Kazal type 1 (SPINK1), an endogenous inhibitor of trypsin like serine proteases, is also an important regulator of anoikis resistance in some ovarian cancers. In this study, we aimed to dissect the role of SPINK1 specifically in OCCC, defining its contribution to anoikis resistance using cultured OCCC cell lines and elucidating its mechanism of action. We compared anoikis resistance of cells with endogenous SPINK1 expression versus cells in which SPINK1 was silenced using lentiviral shRNA constructs, when culturing cells on ultra-low attachment plates to mimic cell detachment from the extracellular matrix. We found that knockdown of SPINK1 reduced survival and stimulated apoptotic pathways in OCCC cells grown under detached conditions, implicating SPINK1 in anoikis resistance of OCCC cells. As a secreted protease inhibitor, SPINK1 may be expected to confer anoikis resistance by inhibiting an extracellular serine protease involved in triggering anoikis. Because many proteases represent potential targets of SPINK1, we have designed a strategy using Activity Based Protein Profiling (ABPP) to discover the targets of SPINK1 from among this large pool of candidates. In pilot studies, we have successfully used a novel activity-based probe to covalently label the active sites of serine proteases secreted from OCCC cells. In ongoing efforts, we are optimizing methods to identify labeled proteases with high sensitivity using tandem mass spectrometry. We will then identify those proteases regulated by SPINK1 through comparison of labeled proteomes from OCCC cells with and without SPINK1 treatment,, and candidate proteases will be further analyzed for their role in triggering anoikis. The identification of SPINK1 regulated proteases that are responsible for mediating anoikis in our models will give insight into important mechanisms whereby tumor cells acquire resistance to anoikis in OCCC. In-depth understanding of anoikis resistance, a critical component of ovarian cancer progression and metastasis, may lead to novel biomarkers of disease progression as well as important therapeutic targets. Citation Format: Christine Mehner, Mathew A. Coban, Alexandra Hockla, Derek C. Radisky, Evette S. Radisky. Serine protease inhibitor Kazal type 1 (SPINK1) drives anoikis resistance in ovarian clear cell carcinoma [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 442.

Objectives. The aim of our study was to compare the efficacy and safety of S-1-based therapy (SBT) versus 5-fluorouracil-based therapy (FBT) for advanced colorectal cancer (ACRC). Methods. A meta-analysis of all eligible randomized controlled trials (RCTs) was performed using RevMan 5.1.0 software. Results. A total of 1625 patients from twelve RCTs including 820 patients in the SBT group and 805 patients in the FBT group were available for analysis. The meta-analysis of overall survival (hazards ratio HR = 0.94, 95% CI = 0.80–1.10), progression-free survival (HR = 1.03, 95% CI = 0.91–1.18), and overall response rate (odds ratio OR = 1.23, 95% CI = 1.00–1.53) showed no statistical significance between SBT group and FBT group. The statistically significant differences in the meta-analysis indicated less incidence of graded 3-4 neutropenia (OR = 0.49, 95% CI = 0.35–0.68) and nausea/vomit (OR = 0.41, 95% CI = 0.23–0.72) in the SBT group, and there was no statistically significant difference in the incidence of grade 3-4 anemia, thrombocytopenia, leucopenia, diarrhea, and treatment-related deaths between two groups. Conclusions. SBT had similar efficacy and better safety than FBT and was an attractive alternative to FBT for patients of ACRC, but further investigations in different populations would be needed to confirm it.

Colorectal cancer (CRC) is one of the high incident and lethal malignant tumors, and most of the patients are diagnosed at an advanced stage. The treatment of CRC mainly includes surgery, chemotherapy, radiotherapy and molecular targeted therapy. Despite these approaches have increased overall survival (OS) of CRC patients, the prognosis of advanced CRC remains poor. In recent years, remarkable breakthroughs have been made in tumor immunotherapy, especially immune checkpoint inhibitors (ICIs) therapy, bringing long-term survival benefits to tumor patients. With the increasing wealth of clinical data, ICIs have achieved significant efficacy in the treatment of high microsatellite instability/deficient mismatch repair (MSI-H/dMMR) advanced CRC, but the therapeutic effects of ICIs on microsatellite stable (MSS) advanced CRC patients is currently unsatisfactory. As increasing numbers of large clinical trials are performed globally, patients treated with ICIs therapy also have immunotherapy-related adverse events and treatment resistance. Therefore, a large number of clinical trials are still needed to evaluate the therapeutic effect and safety of ICIs therapy in advanced CRC. This article will focus on the current research status of ICIs in advanced CRC and discuss the current predicament of ICIs treatment.

The Value of Preoperative Radiotherapy in the Treatment of Locally Advanced Nasal Cavity and Paranasal Sinus Squamous Cell Carcinoma: A Single Institutional Experience

Whether serine protease inhibitor Kazal type 1 (SPINK1) being associated with enzalutamide (Enz) resistance and metastasis of castration-resistant prostate cancer (CRPC) has not been clear. SPINK1 promoted Enz resistance by upregulating Androgen receptor splicing variant 7 (ARv7), and enhanced the invasion/migration of Enz-resistant cells via ERK/p38/ MMP9 signaling. Furthermore, miR-5089-5p suppressed SPINK1 mRNA through direct binding to its 3'UTR, and reversed its pro-proliferative and pro-metastatic effects. Mice bearing SPINK1-knockdown Enz-resistant PCa tumors showed significantly longer survival compared with those bearing wild-type tumors, while treatment with miR-5089-5p inhibitor abrogated the protective effects of SPINK1 knockdown. Taken together, SPINK1 can be used as a biomarker of resistance to Enz, and the miR-5089-5p/SPINK1/MAPK/MMP9 axis is a suitable therapeutic target against Enz-resistant and metastatic CRPC.Methods: The expression of SPINK1 in Enz-resistant prostate cancer (PCa) cell lines was detected through next-generation sequencing data and metastatic PCa patients. In vivo and in vitro experiments were performed to investigate the role of SPINK1 in Enz-resistance and metastasis.

Objective. To evaluate the efficacy and safety of a regimen using Irinotecan, 5FU and Leucovorin for patients with advanced or recurrent colorectal cancer. Material and methods. Irinotecan (75 mg/m2) was administered biweekly, while 5FU (600 mg/m2) and Leucovorin (250 mg/m2) were administered weekly, for 6 weeks. Results. The 21 consecutive patients subjected to this regimen showed a good response rate (43%) with minimal toxicity (incidence of grade 3/4: leukopenia and neutropenia, 5%, respectively, and vomiting, 10%). The mean survival time of all 21 patients was 15.7 months. This regimen could be a valid option for patients with advanced colorectal cancer, especially those seeking a good QoL (quality of life) for the remainder of their lives. We evaluated the expression of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and orotate phosphoribosyl transferase (OPRT) mRNAs, and sialyl Lewis X on formalin-fixed, paraffin-embedded colorectal tumor samples. Expression of TS mRNA or sialyl Lewis X was negatively correlated with the response from chemotherapy. Patients with low DPD mRNA expression in the tumor showed a significant longer survival than those with high expression. In patients with high TP mRNA expression, there was a tendency towards a high incidence of leukopenia. Conclusions. Some predictive factors elucidated in this study could contribute to the progress of the tumor-biology based, individualized chemotherapy for colorectal cancer patients.

The combination of CDDP and ARA-C has shown some clinical efficiency as first-line therapy in advanced colorectal cancer. Our study was aimed to evaluate the therapeutic activity of this combination in advanced colorectal cancer who failed 5-fluorouracil (FU) and folinic acid (LV) regimen. Seventeen patients with measureable metastatic colorectal cancer who failed 5FU-LV therapy as first line (n = 14) or second line treatment (n = 3), entered the study. Three patients who recurred during adjuvant treatment with 5FU and levamisol, were also included. Median age was 59.5 (40-69). Performance status was as follows: 0 (n = 5), 1 (n = 11), 2 (n = 3), 3 (n = 1). Site of metastases included liver (n = 16), lung (n = 7), abdomen (n = 2), pelvic recurrences (n = 2), cutaneous (n = 1). Seven patients had 2 metastatic sites and two 3. The treatment was given as follows: ARA-C 75 mg/m2/day, days 1-3, followed 1 hour later by CDDP 30 mg/m2/day, days 1-3, every 28 days. The median number of cycles was 3 (range: 1-6 cycles). All patients but one were evaluable for both response and toxicity. Of these patients, 50% experienced severe hematologic toxicity and nonhematologic toxicity mainly consisted of fatigue and/or vomiting. No objective response was observed, but there were 3 stabilizations and 16 progressive diseases. Median time to progression was 10 weeks. Thus, the CDDP/ARA-C regimen is not of clinical value as salvage therapy in advanced colorectal cancer because of its toxicity and its lack of efficiency.

11506 Background: The ISG-STS 1001 was an international, randomized, phase III, clinical trial for localized, high-risk, soft tissue sarcoma comparing neoadjuvant chemotherapy (ChT) with a standard regimen of epirubicin plus ifosfamide (EI) versus an histology-tailored regimen (HT) in five histologic types, within the context of an integrated multimodality strategy. In addition, in this study, a parallel group of patients (pts) was not randomized but just registered and treated with EI. Radiation-therapy (RT) could be delivered either pre-operatively (concurrent to ChT) or post-operatively, according to clinical judgement. Final results of ISG-STS 1001, published in 2020, showed a benefit in favor of EI, in terms of overall survival, in comparison to HT. Herein, we analyzed tolerability and activity of ChT with EI either in the standard arm of the trial or in the parallel group, whether alone and concurrent to RT. Methods: The EI regimen was made up of epirubicin 120 mg/m² plus ifosfamide 9 g/m². RT was delivered at a dose of 44-50 Gy pre-operatively or 60-66 Gy post-operatively. In the current analysis, toxicities related to EI were analyzed separately in the group receiving concurrent pre-operative ChT and RT and in the group treated with pre-operative ChT alone and receiving RT post-operatively. Surgical complications and radiological response according to RECIST were analyzed in the above mentioned two groups. Data on ChT dose-intensity will be provided. Results: Among the 548 pts (287 randomized and 261 registered) included in the ISG-STS 1001, 289 pts were considered for the current analyses (111 pts randomized in the EI arm and 178 pts just registered). 146 pts were treated with pre-operative RT and 143 with post-operative RT. In regard to toxicities, no statistically significant differences were found between pts treated with pre-operative concurrent ChT and RT and pts treated with pre-operative ChT alone. When surgical post-operative complications were considered, a higher number of wound dehiscence (9% vs 3.5%, respectively, p = 0.053) and seroma (10.5% vs 3%, respectively, p = 0.009) were observed in pts treated with pre-operative concurrent ChT and RT compared to pts treated with pre-operative ChT alone. Finally, a statistically significant association between RECIST response and pre-operative RT was found (p = 0.041), RECIST partial responses (PR) being 19% and 10% in pts receiving concurrent pre-operative ChT plus RT and in pts treated with pre-operative ChT alone, respectively. Conclusions: The concurrent administration of EI and RT was confirmed to be feasible and safe, resulting in an increased number of PR. Also given the final results of this randomized trial, favoring the EI arm, this combination may help when tumors are of borderline resectability or function preservation is a goal.

522P - Broad detection of alterations predicted to confer lack of benefit from EGFR antibodies or sensitivity to targeted therapy in advanced colorectal cancer

A KRAS mutation represented the first genomic biomarker to predict lack of benefit from anti-epidermal growth factor receptor (EGFR) antibody therapy in advanced colorectal cancer (CRC). Expanded RAS testing has further refined the treatment approach, but understanding of genomic alterations underlying primary and acquired resistance is limited and further study is needed. We prospectively analyzed 4,422 clinical samples from patients with advanced CRC, using hybrid-capture based comprehensive genomic profiling (CGP) at the request of the individual treating physicians. Comparison with prior molecular testing results, when available, was performed to assess concordance. We identified a RAS/RAF pathway mutation or amplification in 62% of cases, including samples harboring KRAS mutations outside of the codon 12/13 hotspot region in 6.4% of cases. Among cases with KRAS non-codon 12/13 alterations for which prior test results were available, 79 of 90 (88%) were not identified by focused testing. Of 1,644 RAS/RAF wild-type cases analyzed by CGP, 31% harbored a genomic alteration (GA) associated with resistance to anti-EGFR therapy in advanced CRC including mutations in PIK3CA, PTEN, EGFR, and ERBB2. We also identified other targetable GA, including novel kinase fusions, receptor tyrosine kinase amplification, activating point mutations, as well as microsatellite instability. Extended genomic profiling reliably detects alterations associated with lack of benefit to anti-EGFR therapy in advanced CRC, while simultaneously identifying alterations potentially important in guiding treatment. The use of CGP during the course of clinical care allows for the refined selection of appropriate targeted therapies and clinical trials, increasing the chance of clinical benefit and avoiding therapeutic futility. Comprehensive genomic profiling (CGP) detects diverse genomic alterations associated with lack of benefit to anti-epidermal growth factor receptor therapy in advanced colorectal cancer (CRC), as well as targetable alterations in many other genes. This includes detection of a broad spectrum of activating KRAS alterations frequently missed by focused molecular hotspot testing, as well as other RAS/RAF pathway alterations, mutations shown to disrupt antibody binding, RTK activating point mutations, amplifications, and rearrangements, and activating alterations in downstream effectors including PI3K and MEK1. The use of CGP in clinical practice is critical to guide appropriate selection of targeted therapies for patients with advanced CRC.

Background: Anti-EGFR antibodies are a standard care for advanced KRAS-wild type colorectal cancers. Circulating tumor DNA (ctDNA) monitoring during therapy can detect emergence of KRAS mutant clones and early resistance to therapy.Case Presentation: We describe a 61-years-old man presenting a metastatic and recurrent rectal cancer treated with different chemotherapy regimens. His tumor was KRAS wild-type based on tissue analysis and he was treated sequentially with cetuximab-based chemotherapy, chemotherapy alone and panitumumab-based chemotherapy. We performed sequential analysis of ctDNA using droplet digital PCR (ddPCR) and a commercial assay designed for the detection of frequent KRAS mutations during his clinical follow-up. Prior to the first cetuximab-based chemotherapy ctDNA analysis demonstrated an absence of KRAS mutations. Emergence of KRAS mutations in ctDNA occurred ~3 months after treatment initiation and preceded clinical and imaging progression in about 2 months. Fractional abundance of KRAS mutation rapidly increased to 70.7% immediately before a chemotherapy alone regimen was initiated. Interestingly, KRAS mutation abundance decreased significantly during the first two months of chemotherapy, reaching a fractional abundance of 3.0%, despite minimal clinical benefit with this therapy. Re-challenge with a different anti-EGFR antibody was attempted as later line, but high levels of KRAS mutations in ctDNA before therapy correlated with an absence of clinical benefit.Conclusions: The monitoring of resistance mutations in KRAS using ctDNA during the treatment of KRAS wild-type advanced colorectal cancers can detect the emergence of resistant clones prior to clinical progression. Dynamics of resistant clones may alter during periods on and off anti-EGFR antibodies, detecting window of opportunities for a re-challenge with these therapies.

Locally advanced, inoperable, and recurrent colorectal cancer requires multitechnique therapy to achieve optimal control and palliation. The role of radiation therapy as an adjuvant in resectable rectal cancer has been studied extensively in clinical trials, but its role in more advanced disease has not been explored to the same extent. The use of radiation in colonic rather than rectal cancer is more problematic because of natural tissue tolerance constraints in the abdomen versus the pelvis. The current and past role of radiation in advanced colorectal cancer will be reviewed, and avenues of ongoing and future investigation will be outlined. The role of radiation for palliation also will be discussed.

This multicenter phase II study was designed to determine the efficacy and tolerability of oxaliplatin in combination with levofolinate and infusion 5-fluorouracil (FOLFOX4) as first-line therapy for Japanese patients with unresectable metastatic colorectal cancer. Sixty consecutive patients with histologically confirmed advanced or metastatic colorectal cancer were enrolled in the study. Treatment was repeated every 2 weeks until disease progression or unacceptable toxicity occurred. Two patients were ineligible. Toxicity was evaluated in 60 patients, who had received a part or all of the protocol therapy. A partial response was observed in 20 patients. The overall response rate was 34.5% (95% CI, 22.5%-48.1%) and the tumor control rate (partial response + stable disease) was 82.8%. The median progression-free survival was 6.9 months (95% CI, 5.1-9.8 months), and the median overall survival was 31.5 months (95% CI, 18.1-40.1 months). There were no toxicity-related deaths. Grade 3 or 4 neutropenia occurred in 48.3% of patients and often caused a delay in the subsequent treatment course. Mild to moderate cumulative peripheral sensory neuropathy affected 71.7% of patients. The results showed good tolerability and efficacy for first-line FOLFOX4 in the treatment of patients with advanced colorectal cancer, indicating the promise of this regimen as first-line therapy for advanced colorectal cancer in the Japanese population.