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The standard treatment approach for stage II/III rectal cancer is neoadjuvant chemoradiation therapy (nCRT) followed by surgery. In recent years, new treatment approaches have led to higher rates of complete tumor eradication combined with organ-preservation strategies. However, better tools are still needed to personalize therapy for the individual patient. In this prospective observational study, we analyzed colon-derived cell-free (cf)DNA (c-cfDNA) using a tissue-specific DNA methylation signature, and its association with therapy outcomes. Analyzing plasma samples (n = 303) collected during nCRT from 37 patients with locally advanced rectal cancer (LARC), we identified colon-specific methylation markers that discriminated healthy individuals from patients with untreated LARC (area under the curve, 0.81; 95% confidence interval, 0.70-0.92; P 0.0001). Baseline c-cfDNA predicted tumor response, with increased levels linked to larger residual cancer. c-cfDNA measured after the first week of therapy identified patients with maximal response and complete cancer eradication, who had significantly lower c-cfDNA compared with those who had residual disease (8.6 vs 57.7 average copies/mL, respectively; P = 0.013). Increased c-cfDNA after one week of therapy was also associated with disease recurrence. Methylation-based liquid biopsy can predict nCRT outcomes and facilitate patient selection for escalation and de-escalation strategies.

Background: Biliary tract cancers, which arise from the intrahepatic or extrahepatic bile ducts and the gallbladder, generally have a poor prognosis and are rising in incidence worldwide. The standard-of-care treatment for advanced biliary tract cancer is chemotherapy with gemcitabine and cisplatin. Because most biliary tract cancers have an immune-suppressed microenvironment, immune checkpoint inhibitor monotherapy is associated with a low objective response rate. We aimed to assess whether adding the immune checkpoint inhibitor pembrolizumab to gemcitabine and cisplatin would improve outcomes compared with gemcitabine and cisplatin alone in patients with advanced biliary tract cancer. Methods: KEYNOTE-966 was a randomised, double-blind, placebo-controlled, phase 3 trial done at 175 medical centres globally. Eligible participants were aged 18 years or older; had previously untreated, unresectable, locally advanced or metastatic biliary tract cancer; had disease measurable per Response Evaluation Criteria in Solid Tumours version 1.1; and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible participants were randomly assigned (1:1) to pembrolizumab 200 mg or placebo, both administered intravenously every 3 weeks (maximum 35 cycles), in combination with gemcitabine (1000 mg/m2 intravenously on days 1 and 8 every 3 weeks; no maximum duration) and cisplatin (25 mg/m2 intravenously on days 1 and 8 every 3 weeks; maximum 8 cycles). Randomisation was done using a central interactive voice-response system and stratified by geographical region, disease stage, and site of origin in block sizes of four. The primary endpoint of overall survival was evaluated in the intention-to-treat population. The secondary endpoint of safety was evaluated in the as-treated population. This study is registered at ClinicalTrials.gov, NCT04003636. Findings: Between Oct 4, 2019, and June 8, 2021, 1564 patients were screened for eligibility, 1069 of whom were randomly assigned to pembrolizumab plus gemcitabine and cisplatin (pembrolizumab group; n=533) or placebo plus gemcitabine and cisplatin (placebo group; n=536). Median study follow-up at final analysis was 25·6 months (IQR 21·7–30·4). Median overall survival was 12·7 months (95% CI 11·5–13·6) in the pembrolizumab group versus 10·9 months (9·9–11·6) in the placebo group (hazard ratio 0·83 [95% CI 0·72–0·95]; one-sided p=0·0034 [significance threshold, p=0·0200]). In the as-treated population, the maximum adverse event grade was 3 to 4 in 420 (79%) of 529 participants in the pembrolizumab group and 400 (75%) of 534 in the placebo group; 369 (70%) participants in the pembrolizumab group and 367 (69%) in the placebo group had treatment-related adverse events with a maximum grade of 3 to 4. 31 (6%) participants in the pembrolizumab group and 49 (9%) in the placebo group died due to adverse events, including eight (2%) in the pembrolizumab group and three (1%) in the placebo group who died due to treatment-related adverse events. Interpretation: Based on a statistically significant, clinically meaningful improvement in overall survival compared with gemcitabine and cisplatin without any new safety signals, pembrolizumab plus gemcitabine and cisplatin could be a new treatment option for patients with previously untreated metastatic or unresectable biliary tract cancer. Funding: Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

5FU and CPT11 display opposite effects on β-catenin localization in CRC colons (S1); 5FU and CPT11 display opposite effects on MDSC accumulation and CD247 expression in the colons of CRC-mice (S2); 5FU or CPT11 chemotherapies do not alter the elevated Treg levels in spleens from CRC-mice (S3); A combined 5FU and CPT11 therapy preserves immunosuppression (S4); A schematic representation of mouse model for CRC in which MDSCs were in vivo depleted in CPT11 treated mice by Gr1 mAb administration every 3 days (S5); 5FU and CPT11 differently affect monocytic/granulocytic MDSC sensitivity to apoptosis (S6); 5FU and CPT11 treatments display opposite effects on mRNA expression levels of pro-inflammatory molecules (S7); 5FU and CPT11 treatments differently affect the immunological profile of mice exhibiting a pathology free chronic inflammation (S8).

Primers for quantitative Real Time PCR.

Legend for Supplementary Figures S1-S8.

Lynch syndrome is an inherited cancer predisposition syndrome caused by germline defects in any of the mismatch repair (MMR) genes. Diagnosis of carriers makes precision prevention, early detection, and tailored treatment possible. Herein we report a novel founder deletion of 18,758 bp, mediated by Alu repeats on both sides, detected in Ethiopian Jews. The deletion, which encompasses exon 9–10 of the MSH2 coding sequence, is associated mainly with early-onset MSH2/MSH6-deficient colorectal cancer (CRC) and liposarcoma. Testing of 35 members of 5 seemingly unrelated families of Ethiopian origin yielded 10/21 (48%) carriers, of whom 9 had CRC. Age at first tumor diagnosis ranged from 16 to 89 years. Carriers from the oldest generations were diagnosed after age 45 years (mean 57), and carriers from the younger generation were diagnosed before age 45 years (mean 30). Awareness of this founder deletion is important to improve patient diagnosis, institute surveillance from an early age, and refer patients for genetic counseling addressing the risk of bi-allelic constitutional MMR deficiency syndrome.

Background The prognosis of gastric cancer (GC) is poor with a median overall survival (OS) of less than 12 months in advanced-stage disease. The search for distinct genetic subgroups of GC patients and predictive biomarkers is ongoing. While BRCA1 or BRCA2 germline mutations (gBRCAm) have potential therapeutic implications in ovarian, breast and pancreatic cancers, their significance in GC patients has not been established. Patients and methods A retrospective multi-center data analysis of GC patients with gBRCAm was conducted, detailing the clinical characteristics and disease course in this unique subset of patients. Results Ten GC patients with gBRCAm were identified, six of them with metastatic disease. The median OS of all ten GC patients was 47.5 (13-192) months. Median OS for patients diagnosed with operable disease was 55.5 (13-192) months and of the patients with metastatic disease (calculated from metastatic disease diagnosis) 32 (15-52) months with an exceptional 1-, 2- and 3-year survival rate of 100%, 83.3% and 50%, respectively. Conclusion These preliminary data suggest that gBRCAm in GC patients are associated with a favorable prognosis. Furthermore, gBRCAm might be a predictive biomarker to DNA-damaging agents response in GC patients, similarly to its established role in other malignancies. Further research is needed to confirm our findings.

Adenocarcinomas of the gastroesophageal junction (GEJ) are tumors whose incidence rates increased significantly in recent years. These tumors have a poor prognosis, and are treated with a palliative approach when diagnosed in an advanced stage. Some tumors overexpress PDL-1 proteins which are partially responsible for the "immune escape" of tumor cells. However, this over-expression enables the use of an immunotherapeutic treatment approach. Immunotherapy using anti-PD1/PDL-1 shows promising results in patients with metastatic GEJ tumors. In the present case report, we describe a young patient who was diagnosed with a non-resectable GEJ adenocarcinoma and was found to have almost 100% positivity for PDL-1 in the tumor biopsy, using standard immunohistochemistry. The patient had rapid and complete response to the anti-PD1 antibody treatment with further development of immune mediated side effects.

411 Background: LEAP-015 (NCT04662710) is a randomized, open-label, 2-part, phase 3 study of the safety and efficacy of lenvatinib + pembrolizumab + chemotherapy as a first-line treatment for advanced/metastatic gastroesophageal adenocarcinoma. We report findings from part 1, the safety run-in, of LEAP-015. Methods: Eligible patients had untreated, HER2-negative, locally advanced unresectable or metastatic gastroesophageal adenocarcinoma, measurable disease per RECIST v1.1, and ECOG performance status 0 or 1. In part 1, patients received induction with IV pembrolizumab 400 mg Q6W (×2) + oral lenvatinib 8 mg QD + investigator choice of chemotherapy (capecitabine + oxaliplatin [CAPOX] Q3W ×4 or 5-fluorouracil + leucovorin + oxaliplatin [mFOLFOX6] Q2W ×6) and consolidation with pembrolizumab 400 mg Q6W for ≤16 doses + lenvatinib 20 mg QD; dose-limiting toxicities (DLTs), defined as selected prespecified grade ≥3 adverse events (AEs) or any-grade thromboembolic events, were evaluated for 21 days after the first dose of study intervention. If ≥3 DLTs occurred in either oxaliplatin-containing regimen, then enrollment in part 2 may be delayed to allow for the examination of safety data and to consider design changes. In part 1, the primary end point was safety and tolerability in all patients. Preliminary efficacy was also assessed in part 1. Objective response and disease control rate were assessed per RECIST version 1.1 by blinded independent central review. Results: In part 1, 15 pts received ≥1 dose of lenvatinib + pembrolizumab + chemotherapy. 1 DLT of grade 3 asthenia occurred in the CAPOX cohort and 1 DLT of grade 4 neutropenia occurred in the FOLFOX cohort. Median time from first dose to data cutoff (Oct 13, 2021) was 7 mo (range, 7-9). Treatment-related AEs occurred in 14 patients (93%), with grade 3/4 events in 8 patients (53%). 4 patients (27%) discontinued any drug because of a treatment-related AE, and no patient discontinued all drugs because of a treatment-related AE. No patients died because of a treatment-related AE. No grade ≥3 immune-mediated AEs or infusion reactions occurred. Objective response was reported in 11 of 15 patients (73%; 95% CI, 45-92) who received ≥1 dose of treatment. Disease control rate was reported in 14 of 15 patients (93%; 95% CI, 68-100) who received ≥1 dose of treatment. Conclusions: In the safety run-in of LEAP-015, lenvatinib + pembrolizumab + chemotherapy was associated with a manageable safety profile in the first-line treatment of advanced/metastatic gastroesophageal adenocarcinoma. Preliminary antitumor activity was observed for lenvatinib + pembrolizumab + chemotherapy. Part 2 will evaluate the efficacy and safety of lenvatinib + pembrolizumab + chemotherapy versus chemotherapy in this same patient population and patient accrual is ongoing. Clinical trial information: NCT04662710 .

Pancreatic ductal adenocarcinoma (PDA) is an aggressive metastatic cancer with a very low survival rate. This tumor is hypovascularized and characterized by severe hypoxic regions, yet these regions are not impeded by the oxidative stress in their microenvironment. PDA’s high resilience raises the need to find new effective therapeutic targets. This study investigated the suitability of methionine aminopeptidase 2 (MetAp2), a metallopeptidase known to play an important role in tumor progression, as a new target for treating PDA. In our examination of patient-derived PDA tissues, we found that MetAp2 is highly expressed in metastatic regions compared with primary sites. At the cellular level, we found that the basal expression levels of MetAp2 in pancreatic cancer cells were higher than its levels in endothelial cells. Pancreatic cancer cells showed a significant suppression of proliferation in a dose-dependent manner upon exposure to TNP-470, a selective MetAp2 inhibitor. In addition, a significant reduction in glutathione (GSH) levels - known for its importance in alleviating oxidative stress - was detected in all treated cells, suggesting a possible anti-cancer activity mechanism that would be feasible for treating highly hypoxic PDA tumors. Furthermore, in an orthotopic pancreatic cancer murine model, systemic oral treatment with a MetAp2 inhibitor significantly reduced tumors’ growth. Taken together, our findings indicate that MetAp2 enhances tumor sensitivity to hypoxia and may provide an effective target for treating hypoxic tumors with high expression levels of MetAp2.

Pancreatic adenocarcinoma (PDAC) has a grim prognosis. Molecular and genomic analyses revealed that the striking majority of these tumors are driven by KRAS mutation, currently not amenable to targeted therapy. However, other driver mutations were found in a small fraction of patients. Herein we report of 3 cases of patients with metastatic PDAC and wildtype KRAS, found to harbor BRAF or RET pathogenic alterations. The patients were treated with targeted therapies with variable success. In our opinion, those proof-of-concept cases argue in favor of additional research and clinical trials’ effort in this small but significant PDAC population with uncommon driver mutations.

Acneiform rash, a common toxicity of epidermal growth factor receptor inhibitors (EGFRIs), can cause patient discomfort, warranting changes in treatment. This study investigated the safety, tolerability, and efficacy of a novel doxycycline foam, FDX104 4%, for managing EGFRI-related skin toxicity.This was an exploratory phase 2, randomized, double-blind, placebo-controlled study. Subjects had metastatic colorectal cancer and were being treated with either cetuximab or panitumumab plus chemotherapy. Treatment (twice-daily topical FDX104 4% on one side of the face and vehicle foam on the other for 5 weeks) was initiated 7 ± 3 days prior to EGFRI therapy. Rash severity, safety, and tolerability were evaluated at 2 and 4 weeks after EGFRI start.The mean maximal rash grade was lower with FDX104 4% vs vehicle, and fewer subjects developed moderate-to-severe (grades 2-3) rash. On the Global Severity Score scale, a statistically significant difference favored FDX104 4% over vehicle (P = .047). Adverse events (AEs) (n = 68) occurred in 20 subjects; most were mild or moderate. The most common AEs were oral mucositis, nausea, and vomiting, common to chemotherapy and EGFRI treatment. Study-drug-related AEs were experienced by five subjects and consisted of mild, local skin reactions. No study-drug-related systemic side effects were reported.Twice-daily, topical administration of FDX104 4% as an adjunct to either cetuximab or panitumumab was safe and well tolerated, and appeared to prevent the onset of rash, especially severe rash. CLINICALTRIALS.Trial Registration NCT02239731.

Background The prognosis of gastric cancer (GC) is poor with a median overall survival (OS) of less than 12 months in advanced-stage disease. The search for distinct genetic subgroups of GC patients and predictive biomarkers is ongoing. While BRCA1 or BRCA2 germline mutations (gBRCAm) have potential therapeutic implications in ovarian, breast and pancreatic cancers, their significance in GC patients has not been established. Patients and Methods A retrospective multi-center data analysis of GC patients with gBRCAm was conducted, detailing the clinical characteristics and disease course in this unique subset of patients. Results Ten GC patients with gBRCAm were identified, six of them with metastatic disease. The median OS of all ten GC patients was 47.5 (13–192) months. Median OS for patients diagnosed with operable disease was 55.5 (13–192) months and of the patients with metastatic disease (calculated from metastatic disease diagnosis) 32 (15–52) months with an exceptional 1-, 2- and 3-year survival rate of 100%, 83.3% and 50%, respectively. Conclusion These preliminary data suggest that gBRCAm in GC patients are associated with a favorable prognosis. Furthermore, gBRCAm might be a predictive biomarker to DNA-damaging agents response in GC patients, similarly to its established role in other malignancies. Further research is needed to confirm our findings.

Mucinous colorectal carcinomas (MC) constitute 10% of colorectal malignancies. Recently, an increased risk of colorectal cancer has been demonstrated in germline BRCA1/2 mutation carriers. Furthermore, BRCA1/2 germline mutation carriers have exhibited a higher-than-expected frequency of MC tumors. Here, we investigate the relationship between BRCA mutations and mucinous histology in colorectal carcinoma patients, using both an existing cohort of sequenced colorectal tumors and a prospective case-control study comparing MC and conventional adenocarcinoma (AC) patients tested for BRCA mutations. We discovered that MC tumors exhibit a statistically significantly higher incidence of BRCA mutations in addition to a higher average mutation count when compared to AC tumors in the existing cohort. The strongest predictor of the mutation count was mucinous histology, independently of other variables including microsatellite instability. Contrary to our hypothesis, the first association did not recur in the prospective case-control study, likely due to our pathological definition of MC tumors and small sample size. Finally, we observed a higher tumor mutational burden (TMB) in MC tumors compared with AC tumors. We suggest that the association between MC histology, BRCA mutations, and increased TMB may open the door to the utilization of simple tests (such as histopathologic characterization) to detect patients who may benefit from immunotherapy in colorectal cancer.

Summary Background Patients with advanced gastric or gastro-oesophageal junction cancer that progresses on chemotherapy have poor outcomes. We compared pembrolizumab with paclitaxel in patients with advanced gastric or gastro-oesophageal junction cancer that progressed on first-line chemotherapy with a platinum and fluoropyrimidine. Methods This randomised, open-label, phase 3 study was done at 148 medical centres in 30 countries. Eligible patients were randomised (1:1) in blocks of four per stratum with an interactive voice-response and integrated web-response system to receive either pembrolizumab 200 mg every 3 weeks for up to 2 years or standard-dose paclitaxel. Primary endpoints were overall survival and progression-free survival in patients with a programmed cell death ligand 1 (PD-L1) combined positive score (CPS) of 1 or higher. Safety was assessed in all patients, irrespective of CPS. The significance threshold for overall survival was p=0·0135 (one-sided). This trial is registered at ClinicalTrials.gov, number NCT02370498. Findings Between June 4, 2015, and July 26, 2016, 592 patients were enrolled. Of the 395 patients who had a PD-L1 CPS of 1 or higher, 196 patients were assigned to receive pembrolizumab and 199 patients were assigned to receive paclitaxel. As of Oct 26, 2017, 326 patients in the population with CPS of 1 or higher had died (151 [77%] of 196 patients in the pembrolizumab group and 175 [88%] of 199 patients in the paclitaxel group). Median overall survival was 9·1 months (95% CI 6·2–10·7) with pembrolizumab and 8·3 months (7·6–9·0) with paclitaxel (hazard ratio [HR] 0·82, 95% CI 0·66–1·03; one-sided p=0·0421). Median progression-free survival was 1·5 months (95% CI 1·4–2·0) with pembrolizumab and 4·1 months (3·1–4·2) with paclitaxel (HR 1·27, 95% CI 1·03–1·57). In the total population, grade 3–5 treatment-related adverse events occurred in 42 (14%) of the 294 patients treated with pembrolizumab and 96 (35%) of the 276 patients treated with paclitaxel. Interpretation Pembrolizumab did not significantly improve overall survival compared with paclitaxel as second-line therapy for advanced gastric or gastro-oesophageal junction cancer with PD-L1 CPS of 1 or higher. Pembrolizumab had a better safety profile than paclitaxel. Additional trials of pembrolizumab in gastric and gastro-oesophageal cancer are ongoing. Funding Merck Sharp & Dohme, a subsidiary of Merck & Co.

Background Precision treatment of cancer uses biomarker-driven therapy to individualize and optimize patient care. Objective To evaluate real-life clinical experience with biomarker-driven therapy in metastatic gastric and esophageal cancer in Israel. Patients and Methods This multicenter retrospective cohort study included patients with metastatic gastric or esophageal cancer who were treated in the participating institutions and underwent biomarker-driven therapy. Treatment was considered to have a benefit if the ratio between the longest progression-free survival (PFS) post biomarker-driven therapy and the last PFS before the biomarker-driven therapy was ≥1.3. The null hypothesis was that ≤15% of patients gain such benefit. Results The analysis included 46 patients (61% men; median age, 58 years; 57% with poorly-differentiated tumors). At least one actionable (i.e., predictive of response to a specific therapy) biomarker was identified for each patient. Immunohistochemistry was performed on all samples and identified 1–8 (median: 3) biomarkers per patient (most commonly: low TS, high TOPO1, high TOP2A). Twenty-eight patients received therapy after the biomarker analysis (1–4 lines). In the 1st line after biomarker analysis, five patients (18%) achieved a partial response and five (18%) stable disease; the median (range) PFS was 129 (12–1155) days. Twenty-four patients were evaluable for PFS ratio analysis; in seven (29.2%), the ratio was ≥1.3. In a one-sided exact binomial test vs. the null hypothesis, p = 0.019; therefore, the null hypothesis was rejected. Conclusions Our findings demonstrated that implementing biomarker-driven analysis is feasible and could provide clinical benefit for a considerable proportion (~30%) of patients with metastatic gastric or esophageal cancer.

Mutations in the BRCA1/2 genes were recently shown to be associated with an increased risk for colorectal cancer. We characterized the largest cohort available of BRCA1/2 mutation carriers with colorectal cancer. We analyzed 32 patients with lower gastrointestinal cancers and germline BRCA1/2 mutations from two large academic hospital registries; 91% of patients were of Ashkenazi ancestry, 78% were women, and 62.5% were carriers of BRCA1 gene mutations. A high percentage of colorectal tumors (34.5%) had a mucinous histology and were located atypically in the left colon. Two patients had anal cancer with unusual histology and an additional patient had mucinous small bowel carcinoma. Gene expression analysis showed significant correlation between the gene signatures of left mucinous colorectal cancer and basal-like breast cancer. Our results imply that Ashkenazi BRCA1/2 mutation carriers with colorectal cancer might have unique characteristics with a high rate of left-sided, mucinous histology colorectal cancer, and possibly anal carcinoma. This report suggests a phenotypic influence of defects in DNA repair genes on colorectal tumors.

Precision cancer therapy has the potential to revolutionize treatment outcome. While genomic analysis has become central to cancer personalized medicine, recent studies have not shown that it drastically improves patient survival as compared to standard drug selection. Additionally, genomic mutations may suggest several treatment protocols without elucidating which approach will yield the best clinical response. Moreover, for many drugs no genetic predictive biomarkers are available. To advance cancer precision diagnostics, we have developed cResponse, a functional drug sensitivity platform to determine individualized patient treatment regimens. Fresh patient cancer samples are taken by biopsy or resection and sectioned into 300 uM slices which when cultured in the cResponse platform demonstrate similar architecture and tissue proliferation to those found in vivo. We show that cResponse is able to preserve human cancer tissue in 3D together with its microenvironment, including endothelial and immune cells, at a high viability (>90%) with continued cell division for 7 days in over twenty types of solids tumors. Importantly, the high viability of the tissue over an extended period of time allows for a rapid genomic profiling to help prioritize drugs to be tested by cResponse, as well as the capacity to evaluate the effects of slow acting drugs such as targeted therapy. To validate the capacity of the cResponse platform to predict patient response to cancer treatment, forty two patients with different cancer types receiving diverse chemotherapeutic and targeted agents were recruited to the study and their tumors were tested using cResponse prior to initiation of treatment. Cancer types included bladder, pancreatic, lung, colorectal, breast and sarcoma. After five days of treatment ex-vivo, the samples were fixed and designated a viability score (ranging from 0 to 100) based on an algorithm composed of a panel of histological and morphological markers. The cResponse score was compared to the clinical response to treatment of 27 patients for which this data is already available. The results demonstrated that cResponse could predict the patient's response with a specificity of 82% (9/11) and a sensitivity of 93.75% (15/16) when compared to the patient's imaging results. In the future, the integration of this platform in directing anti-cancer treatment may lead to better response rate of cancer patients to therapy. Citation Format: Seth Salpeter, Vered Bar, Sara Aharon, Luba Torovsky, Adi Zundelevich, Hamutal Shachar, Hagit Shapira, Nancy Gavert, Ravid Straussman, Shay Golan, Eli Rosenbaum, Talia Golan, Raanan Berger, Zohar Dotan, Dan Leibovici, Shani Breuer, Yakir Rotenberg, Aviad Zick, Ayala Hubert, Hovav Nechushtan, Guy Neev. A clinical trial of cResponse, a functional assay for cancer precision medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT209.

Genomic DNA is packed by histone proteins that carry a multitude of post-translational modifications that reflect cellular transcriptional state. Cell-free DNA (cfDNA) is derived from fragmented chromatin in dying cells, and as such it retains the histones markings present in the cells of origin. Here, we pioneer chromatin immunoprecipitation followed by sequencing of cell-free nucleosomes (cfChIP-seq) carrying active chromatin marks. Our results show that cfChIP-seq provides multidimensional epigenetic information that recapitulates the epigenetic and transcriptional landscape in the cells of origin. We applied cfChIP-seq to 268 samples including samples from patients with heart and liver pathologies, and 135 samples from 56 metastatic CRC patients. We show that cfChIP-seq can detect pathology-related transcriptional changes at the site of the disease, beyond the information on tissue of origin. In CRC patients we detect clinically-relevant, and patient-specific information, including transcriptionally active HER2 amplifications. cfChIP-seq provides genome-wide information and requires low sequencing depth. Altogether, we establish cell-free chromatin immunoprecipitation as an exciting modality with potential for diagnosis and interrogation of physiological and pathological processes using a simple blood test.One Sentence SummaryChIP-seq of plasma-circulating nucleosomes (cfChIP-seq) from a simple blood test provides detailed information about gene expression programs in human organs, and cancer.

Background Anatomic location of primary tumors across the colon correlate with survival in the metastatic setting, whereas left-sided tumors may exhibit superior survival compared with right-sided tumors. The Oncotype Recurrence Score (RS) assay is a clinically validated predictor of recurrence risk in patients with stage II colorectal cancer (CRC). Previous studies had indicated that without adjuvant chemotherapy, CDX2-negative stage II CRC tumors are associated with a lower rate of disease-free survival than CDX2-positive stage II CRC tumors. We aimed to evaluate whether these two validated prognostic biomarkers may correlate with primary tumor location, and whether tumor location may reflect differential prognosis in stage II CRC. Materials and Methods We retrospectively analyzed patients with T3 mismatch repair-proficient (MMR-P) stage II CRC for whom RS assay was performed. Pathological report was reviewed for exact primary tumor location and CDX2 immunostaining. RS and CDX2 expression were correlated with primary tumor location. Results The analysis included 1,147 patients with MMR-P stage II CRC (median age 69 years [range 29–93]). Tumor distribution across the colon was as follows: 46% (n = 551) were right-sided and 54% (n = 596) were left-sided. RS was higher in right-sided tumors (p = .01). The RS results gradually decreased across the colon (cecum, highest score; sigmoid, lowest score; p = .04). Right-sided tumors exhibited more CDX2-negative tumors (p = .07). Conclusion Our study indicates that right-sided colorectal tumors may display worse prognosis compared with left-sided tumors in MMR-P stage II CRC. Primary tumor location may serve as a prognostic factor that should be taken into account for recurrence risk assessment and consideration of adjuvant treatment.

Summary Factors linking inflammation and cancer are of great interest. We now report that the chromatin-targeting E3 ubiquitin ligase RNF20/RNF40, driving histone H2B monoubiquitylation (H2Bub1), modulates inflammation and inflammation-associated cancer in mice and humans. Downregulation of RNF20 and H2Bub1 favors recruitment of p65-containing nuclear factor κB (NF-κB) dimers over repressive p50 homodimers and decreases the heterochromatin mark H3K9me3 on a subset of NF-κB target genes to augment their transcription. Concordantly, RNF20+/− mice are predisposed to acute and chronic colonic inflammation and inflammation-associated colorectal cancer, with excessive myeloid-derived suppressor cells (MDSCs) that may quench antitumoral T cell activity. Notably, colons of human ulcerative colitis patients, as well as colorectal tumors, reveal downregulation of RNF20/RNF40 and H2Bub1 in both epithelium and stroma, supporting the clinical relevance of our tissue culture and mouse model findings., Graphical Abstract, Highlights • RNF20 and H2Bub1 modulate the NF-kB response • RNF20-deficient mice are prone to colonic inflammation and colorectal cancer • Reduced H2Bub1 may create a pro-tumoral microenvironment • Reduced H2Bub1 is associated with colitis and colorectal cancer in humans, Ubiquitination of histone H2B (H2Bub1), primarily by the E3 ligase RNF20, is reduced in many advanced cancers. Tarcic et al. report that downregulation of RNF20 and H2Bub1 promotes chronic colonic inflammation and inflammation-associated colorectal cancer in mice and humans, partly by augmenting NF-kB activity and attenuating the antitumoral T cell response.

ObjectivesTo evaluate the impact of the 12-gene Colon Cancer Recurrence Score Assay—a clinically validated prognosticator in stage II colon cancer after surgical resection—on adjuvant treatment decisions in T3 mismatch repair proficient (MMR-P) stage II colon cancer in clinical practice.MethodsThis retrospective analysis included all patients with T3 MMR-P stage II colon cancer (Clalit Health Services members) with Recurrence Score results (time frame January 2011 to May 2012). Treatment recommendations pretesting were compared with the treatments received. Changes were categorized as decreased (to observation alone/removing oxaliplatin from the therapy) or increased (from observation alone/adding oxaliplatin to the therapy) intensity.ResultsThe analysis included 269 patients; 58%, 32%, and 10% of the values were in the low (

Background About half of colorectal patients are diagnosed less than 65 years of age and they have a relatively high cure rate. However, little is known about their employment and related risk factors. The aim of the current study was to clarify the association between colorectal cancer (CRC) and subsequent risk of being unemployed. Methods A historical prospective cohort study included baseline socio-demographic measurements of age, sex, ethnicity, residential socio-economic position and education from the 1995 Israeli National Census, cancer incidence between 2000 and 2007 and employment data between 1998 and 2011. Binary logistic regression analyses were used to assess odds ratios for unemployment, while controlling for socio-economic measurements and employment status at 2 years prior to diagnosis. Results The final study population included 885 colorectal patients and 2646 healthy controls. After controlling for confounders, positive associations were found between stages II (odds ratio [OR] = 1.91, 95% confidence interval [CI]: 1.31–2.76 or III (OR = 1.70, 95% CI: 1.13–2.54) and increased risk for unemployment at 2 years. At 4 years follow-up, stages I (OR = 1.56, 95% CI: 1.11–2.19), II (OR = 1.57, 95% CI: 1.09–2.26) and III (OR = 2.28, 95% CI: 1.55–3.37) were associated with increased risk for unemployment. Higher risk was seen among rectal cancer patients and among patients aged ≤50 years old at the time of cancer diagnosis. Conclusions CRC patients are at increased long-term risk for unemployment, especially among rectal cancer and younger patients. The clinical ramifications of our findings emphasise the importance of an accurate evaluation and attention to unemployment status during the care of these patients.

Mutations in MCM9, which encodes DNA helicase, were recently shown to cause a clinical phenotype of primary ovarian failure and chromosomal instability. MCM9 plays an essential role in homologous recombination-mediated double-strand break repair. We describe a multiplex family with early colorectal carcinoma and mixed polyposis associated with primary hypergonadotropic hypogonadism. A combination of whole genome homozygosity mapping as well as exome sequencing and targeted gene sequencing identified a homozygous c.672_673delGGinsC mutation that predicts a truncated protein, p.Glu225Lysfs*4. Our data expand the phenotypic spectrum of MCM9 mutations and suggest a link between MCM9 and inherited predisposition to mixed polyposis and early-onset colorectal cancer.

The currently accepted imaging methods have been a central hurdle to imaging the finer details of tumor behavior in three-dimensional (3D) ex vivo multicellular culture models. In our search for an improved way of imaging tumor behavior in its physiological-like niche, we developed a simple, efficient, and straightforward procedure using standard reagents and imaging equipment that significantly enhanced 3D imaging up to a ~200-micron depth. We tested its efficacy on pancreatic spheroids, prototypes of high-density tissues that are difficult to image. We found we could both save time with this method and extract information about pancreatic tumor spheroids that previously was difficult to obtain. We were able to discern clear differences in the organization of pancreatic tumor spheroids generated from different origins, suggesting cell-specific, inherent, bottom-up organization with a correlation to the level of malignancy. We also examined the dynamic changes in the spheroids at predetermined time points, providing important information related to tissue morphogenesis and its metabolic state. Lastly, this process enabled us to assess a drug vehicle&rsquo, s potential to penetrate dense tumor tissue by improving our view of the inert particles&rsquo, diffusion in the 3D spheroid. This clearing method, a simple procedure, can open the door to more accurate imaging and reveal more about cancer behavior.

Epithelial cells of the intestine undergo rapid turnover and are thought to be cleared via stool. Disruption of tissue architecture, as occurs in colorectal cancer (CRC), results in the release of material from dying intestinal epithelial cells to blood. This phenomenon could be utilized for diagnosis and monitoring of intestinal diseases, if circulating cell-free DNA (cfDNA) derived from intestinal cells could be specifically identified. Here we describe two genomic loci that are unmethylated specifically in intestinal epithelial cells, allowing for sensitive and specific detection of DNA derived from such cells. As expected, intestinal DNA is found in stool, but not in plasma, of healthy individuals. Patients with inflammatory bowel disease (IBD) have minimal amounts of intestinal cfDNA in the plasma, whereas patients with advanced CRC show a strong signal. The intestinal markers are not elevated in plasma samples from patients with pancreatic ductal adenocarcinoma (PDAC), and a combination of intestine- and pancreas-specific markers allowed for robust differentiation between plasma cfDNA derived from CRC and PDAC patients. Intestinal DNA markers provide a mutation-independent tool for monitoring intestinal dynamics in health and disease.

// Talia Golan 1 , Elina Zorde Khvalevsky 2 , Ayala Hubert 3 , Rachel Malka Gabai 2 , Naama Hen 2 , Amiel Segal 4 , Abraham Domb 5 , Gil Harari 6 , Eliel Ben David 7 , Stephen Raskin 1 , Yuri Goldes 1 , Eran Goldin 8 , Rami Eliakim 1 , Maor Lahav 1 , Yael Kopleman 9 , Alain Dancour 8 , Amotz Shemi 2 and Eithan Galun 10 1 The Sackler School of Medicine, The Chaim Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel 2 Silenseed Ltd., Jerusalem, Israel 3 Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel 4 The Gastroenterology Institute, Shaare Zedek Medical Centre, Jerusalem, Israel 5 Institute of Drug Research, School of Pharmacy-Faculty of Medicine, Center for Nanoscience and Nanotechnology and The Alex Grass Centre for Drug Design and Synthesis, The Hebrew University of Jerusalem, Jerusalem, Israel 6 MediStat Ltd., Jerusalem, Israel 7 Hadassah-Hebrew University Medical Centre, Jerusalem, Israel 8 The Gastroenterology Institute, Shaare Zedek Medical Center, Jerusalem, Israel 9 Gastroenterology Institute, Hadassah Hebrew University Medical Center, Jerusalem, Israel 10 The Goldyne Savad Institute for Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel Correspondence to: Talia Golan, email: // Keywords : Pancreatic cancer, KRAS, overall survival, siRNA, polymer implant Received : March 04, 2015 Accepted : May 02, 2015 Published : May 19, 2015 Abstract Purpose: The miniature biodegradable implant siG12D-LODER™ was inserted into a tumor and released a siRNA drug against KRAS(G12D) along four months. This novel siRNA based drug was studied, in combination with chemotherapy, as targeted therapy for Locally Advanced Pancreatic Cancer (LAPC). Methods: An open-label Phase 1/2a study in the first-line setting of patients with non-operable LAPC was initiated. In this study patients were assigned to receive a single dose of siG12D-LODERs , in three escalating dose cohorts (0.025mg, 0.75mg and 3.0mg). Gemcitabine was given on a weekly basis, following the siG12D-LODER TM insertion, until disease progression. The recommended dose was further examined with modified FOLFIRINOX. The follow up period was eight weeks and survival until death. Results: Fifteen patients with LAPC were enrolled. Among the 15 treated patients, the most frequent adverse events observed were grade 1or 2 in severity (89%); five patients experienced serious adverse events (SAEs). In 12 patients analyzed by CT scans, none showed tumor progression, the majority (10/12) demonstrated stable disease and two showed partial response. Decrease in tumor marker CA19-9 was observed in 70% (7/10) of patients. Median overall survival was 15.12 months; 18 month survival was 38.5%. Conclusions: The combination of siG12D-LODER™ and chemotherapy is well tolerated, safe and demonstrated a potential efficacy in patients with LAPC. NCT01188785

Purpose Olaparib is an oral poly (ADP-ribose) polymerase inhibitor with activity in germline BRCA1 and BRCA2 (BRCA1/2) –associated breast and ovarian cancers. We evaluated the efficacy and safety of olaparib in a spectrum of BRCA1/2-associated cancers. Patients and Methods This multicenter phase II study enrolled individuals with a germline BRCA1/2 mutation and recurrent cancer. Eligibility included ovarian cancer resistant to prior platinum; breast cancer with ≥ three chemotherapy regimens for metastatic disease; pancreatic cancer with prior gemcitabine treatment; or prostate cancer with progression on hormonal and one systemic therapy. Olaparib was administered at 400 mg twice per day. The primary efficacy end point was tumor response rate. Results A total of 298 patients received treatment and were evaluable. The tumor response rate was 26.2% (78 of 298; 95% CI, 21.3 to 31.6) overall and 31.1% (60 of 193; 95% CI, 24.6 to 38.1), 12.9% (eight of 62; 95% CI, 5.7 to 23.9), 21.7% (five of 23; 95% CI, 7.5 to 43.7), and 50.0% (four of eight; 95% CI, 15.7 to 84.3) in ovarian, breast, pancreatic, and prostate cancers, respectively. Stable disease ≥ 8 weeks was observed in 42% of patients (95% CI, 36.0 to 47.4), including 40% (95% CI, 33.4 to 47.7), 47% (95% CI, 34.0 to 59.9), 35% (95% CI, 16.4 to 57.3), and 25% (95% CI, 3.2 to 65.1) of those with ovarian, breast, pancreatic, or prostate cancer, respectively. The most common adverse events (AEs) were fatigue, nausea, and vomiting. Grade ≥ 3 AEs were reported for 54% of patients; anemia was the most common (17%). Conclusion Responses to olaparib were observed across different tumor types associated with germline BRCA1/2 mutations. Olaparib warrants further investigation in confirmatory studies.

Recapitulating the tumor microenvironment is a central challenge in the development of experimental model for cancer. To provide a reliable tool for drug development and for personalized cancer therapy, it is critical to maintain key features that exist in the original tumor. Along with this effort, 3-dimentional (3D) cellular models are being extensively studied. Spheroids are self-assembled cell aggregates that possess many important components of the physiological spatial growth and cell-cell interactions. In this study we aimed to investigate the interconnection between tumor and endothelial cells (EC) in hybrid spheroids containing either tumor cell (TC) lines or patient derived cancer cells. Preparation protocols of hybrid spheroids were optimized and their morphology and tissue-like features were analyzed. Our finding show that capillary-like structures are formed upon assembly and growth of TC:EC spheroids and that spheroids’ shape and surface texture may be an indication of spatial invasiveness of cells in the extra-cellular matrix (ECM). Establishing a model of hybrid tumor/stroma spheroids has a crucial importance in the experimental approach for personalized medicine, and may offer a reliable and low-cost method for the goal of predicting drug effects.

Tumor genome sequencing is important for increasing our understanding of the development of cancer, which may be affected by different therapies. In the present study, genomic evolution was investigated in a patient with stage IV pancreatic cancer bearing a germline breast cancer 2 (BRCA2) mutation. The patient received cisplatin, a DNA cross-linking agent, which led to a long-lasting complete response. Eventually the patient developed brain metastasis, suggesting the acquisition of resistance to cisplatin. He subsequently underwent brain lesion resection, radiofrequency ablation and chemotherapy, again resulting in long-lasting response. Samples of blood, pancreatic tumor tissue and brain metastases were collected and the extracted DNA was sequenced. The pancreatic and brain lesions, when compared with the blood samples, exhibited mutations in the BRCA1 and checkpoint kinase 2 genes, in addition to the germline BRCA2 mutation. The brain lesion, when compared with the primary tumor, harbored no additional mutations or copy-number variations. These findings suggest that the isolated relapse in the brain was due to pharmacological sanctuary rather than genomic alterations. It may be suggested that the presence of defects in the homologous recombination repair pathways are associated with a good prognosis and clinical sensitivity to agents that damage the DNA in pancreatic cancer.

Naama Halpern,1 Yael Goldberg,2 Luna Kadouri,2 Morasha Duvdevani,2 Tamar Hamburger,2 Tamar Peretz,2 Ayala Hubert2 1Institute of Oncology, The Chaim Sheba Medical Center, Tel Hashomer, Israel; 2Sharett Institute of Oncology, Hadassah Medical Center, Hebrew University, Jerusalem, Israel Background: The prognostic and predictive significance of the high-level microsatellite instability (MSI-H) phenotype in various malignancies is unclear. We describe the characteristics, clinical course, and outcomes of patients with MSI-H malignancies treated in a real-life hospital setting.Patients and methods: A retrospective analysis of MSI-H cancer patient files was conducted. We analyzed the genetic data, clinical characteristics, and oncological treatments, including chemotherapy and surgical interventions.Results: Clinical data of 73 MSI-H cancer patients were available. Mean age at diagnosis of first malignancy was 52.3years. Eight patients (11%) had more than four malignancies each. Most patients (76%) had colorectal cancer (CRC). Seventeen patients (23%) had only extracolonic malignancies. Eighteen women (36%) had gynecological malignancy. Nine women (18%) had breast cancer. Mean follow-up was 8.5years. Five-year overall survival and disease-free survival of all MSI-H cancer patients from first malignancy were 86% and 74.6%, respectively. Five-year overall survival rates of stage 2, 3, and 4 MSI-H CRC patients were 89.5%, 58.4%, and 22.9%, respectively.Conclusion: Although the overall prognosis of MSI-H cancer patients is favorable, this advantage may not be maintained in advanced MSI-H CRC patients. Keywords: microsatellite instability, malignancy, treatment, outcome

Background Data suggest selective internal radiotherapy (SIRT) in third-line or subsequent therapy for metastatic colorectal cancer has clinical benefit in patients with colorectal liver metastases with liver-dominant disease after chemotherapy. The FOXFIRE, SIRFLOX, and FOXFIRE-Global randomised studies evaluated the efficacy of combining first-line chemotherapy with SIRT using yttrium-90 resin microspheres in patients with metastatic colorectal cancer with liver metastases. The studies were designed for combined analysis of overall survival. Methods FOXFIRE, SIRFLOX, and FOXFIRE-Global were randomised, phase 3 trials done in hospitals and specialist liver centres in 14 countries worldwide (Australia, Belgium, France, Germany, Israel, Italy, New Zealand, Portugal, South Korea, Singapore, Spain, Taiwan, the UK, and the USA). Chemotherapy-naive patients with metastatic colorectal cancer (WHO performance status 0 or 1) with liver metastases not suitable for curative resection or ablation were randomly assigned (1: 1) to either oxaliplatin-based chemotherapy (FOLFOX: leucovorin, fluorouracil, and oxaliplatin) or FOLFOX plus single treatment SIRT concurrent with cycle 1 or 2 of chemotherapy. In FOXFIRE, FOLFOX chemotherapy was OxMdG (oxaliplatin modified de Gramont chemotherapy; 85 mg/m(2) oxaliplatin infusion over 2 h, L-leucovorin 175 mg or D,L-leucovorin 350 mg infusion over 2 h, and 400 mg/m(2) bolus fluorouracil followed by a 2400 mg/m(2) continuous fluorouracil infusion over 46 h). In SIRFLOX and FOXFIRE-Global, FOLFOX chemotherapy was modified FOLFOX6 (85 mg/m(2) oxaliplatin infusion over 2 h, 200 mg leucovorin, and 400 mg/m(2) bolus fluorouracil followed by a 2400 mg/m(2) continuous fluorouracil infusion over 46 h). Randomisation was done by central minimisation with four factors: presence of extrahepatic metastases, tumour involvement of the liver, planned use of a biological agent, and investigational centre. Participants and investigators were not masked to treatment. The primary endpoint was overall survival, analysed in the intention-to-treat population, using a two-stage meta-analysis of pooled individual patient data. All three trials have completed 2 years of follow-up. FOXFIRE is registered with the ISRCTN registry, number ISRCTN83867919. SIRFLOX and FOXFIRE-Global are registered with ClinicalTrials.gov, numbers NCT00724503 (SIRFLOX) and NCT01721954 (FOXFIRE-Global). Findings Between Oct 11, 2006, and Dec 23, 2014, 549 patients were randomly assigned to FOLFOX alone and 554 patients were assigned FOLFOX plus SIRT. Median follow-up was 43.3 months (IQR 31.6-58.4). There were 411 (75%) deaths in 549 patients in the FOLFOX alone group and 433 (78%) deaths in 554 patients in the FOLFOX plus SIRT group. There was no difference in overall survival (hazard ratio [HR] 1.04, 95% CI 0.90-1.19; p=0.61). The median survival time in the FOLFOX plus SIRT group was 22.6 months (95% CI 21.0-24.5) compared with 23.3 months (21.8-24.7) in the FOLFOX alone group. In the safety population containing patients who received at least one dose of study treatment, as treated, the most common grade 3-4 adverse event was neutropenia (137 [24%] of 571 patients receiving FOLFOX alone vs 186 (37%) of 507 patients receiving FOLFOX plus SIRT). Serious adverse events of any grade occurred in 244 (43%) of 571 patients receiving FOLFOX alone and 274 (54%) of 507 patients receiving FOLFOX plus SIRT. 10 patients in the FOLFOX plus SIRT group and 11 patients in the FOLFOX alone group died due to an adverse event; eight treatment-related deaths occurred in the FOLFOX plus SIRT group and three treatment-related deaths occurred in the FOLFOX alone group. Interpretation Addition of SIRT to first-line FOLFOX chemotherapy for patients with liver-only and liver-dominant metastatic colorectal cancer did not improve overall survival compared with that for FOLFOX alone. Therefore, early use of SIRT in combination with chemotherapy in unselected patients with metastatic colorectal cancer cannot be recommended. To further define the role of SIRT in metastatic colorectal cancer, careful patient selection and studies investigating the role of SIRT as consolidation therapy after chemotherapy are needed. Copyright (C) The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license.

Diagnosis of Lynch syndrome (LS) may be complex. Knowledge of mutation spectrum and founder mutations in specific populations facilitates the diagnostic process. Aim of the study is to describe genetic features of LS in the Israeli population and report novel and founder mutations. Patients were studied at high-risk clinics. Diagnostics followed a multi-step process, including tumor testing, gene analysis and testing for founder mutations. LS was defined by positive mutation testing. We diagnosed LS in 242 subjects from 113 families coming from different ethnicities. We identified 54 different mutations; 13 of them are novel. Sixty-seven (59%) families had mutations in MSH2, 20 (18%) in MSH6, 19 (17%) in MLH1 and 7 (6%) in PMS2; 27% of the MSH2 mutations were large deletions. Seven founder mutations were detected in 61/113 (54%) families. Constitutional mismatch repair deficiency (CMMR-D) was identified in five families. Gene distribution in the Israeli population is unique, with relatively high incidence of mutations in MSH2 and MSH6. The mutation spectrum is wide; however, 54% of cases are caused by one of seven founder mutations. CMMR-D occurs in the context of founder mutations and consanguinity. These features should guide the diagnostic process, risk estimation, and genetic counseling.

Pancreatic ductal adenocarcinoma (PDA) represents an unmet therapeutic challenge. PDA is addicted to the activity of the mutated KRAS oncogene which is considered so far an undruggable therapeutic target. We propose an approach to target KRAS effectively in patients using RNA interference. To meet this challenge, we have developed a local prolonged siRNA delivery system (Local Drug EluteR, LODER) shedding siRNA against the mutated KRAS (siG12D LODER). The siG12D LODER was assessed for its structural, release, and delivery properties in vitro and in vivo. The effect of the siG12D LODER on tumor growth was assessed in s.c. and orthotopic mouse models. KRAS silencing effect was further assessed on the KRAS downstream signaling pathway. The LODER-encapsulated siRNA was stable and active in vivo for 155 d. Treatment of PDA cells with siG12D LODER resulted in a significant decrease in KRAS levels, leading to inhibition of proliferation and epithelial-mesenchymal transition. In vivo, siG12D LODER impeded the growth of human pancreatic tumor cells and prolonged mouse survival. We report a reproducible and safe delivery platform based on a miniature biodegradable polymeric matrix, for the controlled and prolonged delivery of siRNA. This technology provides the following advantages: (i) siRNA is protected from degradation; (ii) the siRNA is slowly released locally within the tumor for prolonged periods; and (iii) the siG12D LODER elicits a therapeutic effect, thereby demonstrating that mutated KRAS is indeed a druggable target.

Thymidine kinase 1 (TK1) is involved in DNA synthesis and is considered a reliable and sensitive marker of cell proliferation. The aim of this study was to investigate the prognostic value of measurements of serum TK1 activity following tumor ablation.This study was performed on 32 patients with renal cell carcinoma (RCC) who had undergone nephrectomy and 35 patients with cancer of different histology with metastases to the liver (n=28) and lung (n=7) treated with radiofrequency ablation (RFA). The TK1 activity was measured with DiviTum (Biovica) immunoassay.In patients with RCC with no evidence of disease during their observation, a significant decrease of the TK1 activity was observed on the day following nephrectomy (p0.0001). The mean calculated half-life ±SEM was 10.8±1.2 h. Taking into account the short half-life, measurements of TK1 were performed 24 h after nephrectomy or RFA of metastases. It was found that elevated TK1 activity (60 Du/l) on the day after nephrectomy independently predicted poor recurrence-free survival (hazard ratio=5.0, p=0.040), after adjustment for T-stage, age and pretreatment TK1. Patients scheduled for RFA averaged 1.4 lesions and an average lesion diameter of 2.2 cm. Multivariate Cox's regression model demonstrated the significant association of any increase of TK1 activity or decrease not reaching ≤60 Du/l on the day after ablation with poor progression-free survival (hazard ratio=4.6, p=0.001), after adjustment for the type of primary tumor, the number and size of metastases.The half-life for serum TK1 activity is 10.8±1.2 h. The measurements of TK1 activity following nephrectomy or RFA of metastases could be an important tool in prognostic evaluation.