Unresectable mCRC Research Articles

Current status of palliative care for patients with unresectable metastatic colorectal cancer in China: a questionnaire-based survey

Objective: To analyze the current adoption of palliative care by patients with unresectable metastatic colorectal cancer (mCRC) in China. Methods: From 1 March 2023 to 30 June 2023, a questionnaire survey was conducted by random sampling. An exclusive research platform for the Blue Book on Clinical Diagnosis and Treatment of Metastatic Colorectal Cancer. An online questionnaire was sent to medical oncologists (including chief physicians, associate chief physicians, attending physicians and residents) in general hospitals and oncology hospitals in four major regions of East, Central, South and Northeast China. The questionnaire contained 28 questions requesting basic information about doctors, the number of patients with mCRC, the status of treatment from first to fourth line and beyond, points concerning treatment of pain in patients with mCRC, and expectations for the future. A medical team was responsible for the quality control of data collected, whereas statisticians performed the data cleaning and sorting and statistical analysis. Results: A total of 300 clinical questionnaires were collected, including 217 (72%) from doctors in general hospitals and 83 (28%) from doctors in oncology hospitals. Senior physicians (including associate chief physicians and chief physicians) accounted for 65% of the respondents, attending physicians 30%, and residents 5%. Within 3 months (average for each month), 46.4±26.6% patients were diagnosed with recurrent or unresectable mCRC by each physician, 51.6±26.8% of the patients being in cancer hospitals and 44.4±26.3% in general hospitals. One hundred percent of patients receiving first-line treatment received palliative care, as did 80.3% of those receiving second-line treatment, 58.2% of those receiving third-line treatment, and 35.1% of those receiving ≥fourth-line treatment. The primary factor governing selection of first-line treatment was guideline recommendations, whereas comorbidities and the patients' physical status dictated second line to fourth line treatment. Standard first-line treatment was administered to 93.8% of eligible patients, standard second-line treatment to 94.3%; and standard third-line treatment to 73.5%. First-line therapy included targeted therapy in 63.6% of patients and immunotherapy in 2.8%; second-line therapy included targeted therapy in 63.0% of patients and immunotherapy in 2.0%; third-line therapy included targeted therapy in 59.2% of patients and immunotherapy in 2.2%; and fourth-line therapy included targeted therapy in 48.7% of patients and immunotherapy in 3.1%. First-line treatment lasted an average of 9.6 months, second-line treatment 6.7 months, third-line treatment 4.9 months, and fourth-line treatment 3.7 months. More than 70% of the patients maintained a good quality of life after receiving first and second-line treatment and more than 60% of them had ECOG performance scores of 0-1. After receiving third- and fourth-line treatment, 50%-60% of patients maintained a good quality of life and 40%-50% of them maintained ECOG performance scores of 0-1. The survey also revealed that the main deficiencies in treatment were limited effectiveness of third-line treatment, insufficient availability and opportunity for clinical research, popularity of new drugs or new drug combination strategies, and limited channels for participation in multidisciplinary diagnosis and treatment. Clinicians reported looking forward to participating in more clinical research on new drugs, hearing about the experience of experts in the field, and discovery of new targets and new drugs that increased the options for posterior line treatment of colorectal cancer. Conclusions: This report objectively summarizes the current situation, treatment difficulties, and expectations of frontline physicians concerning management of mCRC, thus providing a basis for decision-making and future direction for the diagnosis and research on treatment of mCRC.

Prognostic value of liver metastases in colorectal cancer treated by systemic therapy: An ARCAD pooled analysis

BackgroundThe liver is the most frequent site of metastases in colorectal cancer (CRC). This study aimed to assess the response rate and survival outcomes in metastatic CRC patients with non-liver metastases (NLM) compared to those with liver metastases (LM) across different lines of treatment. MethodsA total of 17,924 mCRC patients included in 26 trials from the ARCAD CRC database were analyzed. The analysis was conducted based on the presence or absence of LM across different treatment groups: chemotherapy (CT) alone, CT + anti-VEGF, CT + anti-EGFR in KRAS wild-type tumors, within the first-line (1 L) and second-line (2 L), and patients enrolled in third-line (≥3 L) trials treated with trifluridine/tipiracil or regorafenib or placebo. The endpoints were overall survival (OS), progression-free survival (PFS), and overall response rate (ORR). ResultsOut of the 17,924 patients, 14,066 had LM (30.6 % with only liver involvement and 69.4 % with liver and other metastatic sites), while 3858 patients had NLM. In the CT alone and CT + anti-VEGF subgroups, NLM patients showed better OS and PFS in the 1 L and 2 L settings. However, in the CT + anti-EGFR 1 L and 2 L subgroups, there was no significant difference in OS and PFS between NLM and LM patients. In the ≥ 3 L subgroups, better OS and PFS were observed in NLM patients. ORRs were higher in LM patients than in NLM patients across all cohorts treated in the 1 L and only in the anti-EGFR cohort in the 2 L. ConclusionLM is a poor prognostic factor for mCRC increasing from 1 L to ≥ 3 L except for patients in 1 L and 2 L receiving CT+anti-EGFR. These data justify using LM as a stratification factor in future trials for patients with unresectable mCRC.

Updated survival results of BBCAPX-II: Sintilimab combined with bevacizumab and CapeOx as first-line treatment in patients with RAS-mutant, microsatellite stable, unresectable metastatic colorectal cancer.

3563 Background: Microsatellite stable (MSS) and RAS-mutant metastatic colorectal cancer (mCRC) patients are characterized by an immunosuppressive microenvironment and a low response rate to immunotherapy. Sintilimab plus bevacizumab and CapeOX (BBCAPX) has proved its efficacy and safety in above unresectable mCRC patients (Ying Yuan et al. ASCO 2023 and Xuefeng Fang et al. ASCO 2022). Here, we report updated survival results of this single arm, open-label, phase 2 trial. Methods: Eligible patients were aged 18 to 75 years with histologically confirmed unresectable metastatic colorectal adenocarcinoma by multidisciplinary team, and had RAS gene mutation and confirmed MSS status. All patients received treatment with sintilimab (200 mg, day 1) plus bevacizumab (7.5mg/kg, day 1) and oxaliplatin (135 mg/m2, day 1) and capecitabine (1g/m2, bid, day 1-14) of each 21-day cycle. The primary endpoint included objective response rate (ORR) and adverse events. Secondary endpoint was disease control rate (DCR) and progression-free survival (PFS). Results: From April 2021 to December 2021, 25 patients were enrolled. The ORR was 84% and the DCR was 100%. Six (24%) patients underwent surgical treatment and unexpectedly achieved no evidence of disease status. At the data cut-off day (January 26, 2024), the median PFS in the full analysis set was 17.9 months (95% CI, 8.84-27), and the median PFS in the per-protocol set was 9.79 months (95% CI, 6.44-24.3). Median PFS was 23.7 months (95% CI, 4.8-NA) in the patients with only liver metastasis and 11.5 months (95% CI, 4.83-24.3) in the patients with other metastasis. The PFS rate at 6 months was 84% (95% CI, 70.8-99.7). The PFS rate at 12 months was 56% (95% CI, 39.6-79.3). The most frequent grade 3 or 4 TRAEs were neutropenia (3/25) and increased alanine transaminase (2/25). No grade 5 adverse events occurred during the study. Conclusions: The combination of sintilimab plus bevacizumab and CapeOx showed promising antitumor activity and manageable toxicity in RAS-mutant, MSS, unresectable mCRC. Patients with liver metastases presented better prognosis compared other metastases. Furthermore, we are currently launching a phase III, randomized, open-label, multicentric clinical trial (NCT05171660) to further analyze the effects, safety, and prognostic biomarkers of this regimen. Clinical trial information: NCT04194359 . [Table: see text]

Efficacy of trifluridine/tipiracil in 3rd or 4th line of treatment in patients with advanced or metastatic colorectal cancer: A real-world data analysis with subgroups exploration.

e15576 Background: Patients with unresectable mCRC can achieve long-term overall survival (OS) thanks to modern systemic treatment and subsequent lines of therapy. With effective 1st, 2nd and next lines of therapy, their condition often allows further lines of treatment. Since publication of RECOURSE study, one of the most frequently used drugs in the 3rd or 4th line is trifluridine/tipiracyl (FTD/TPI). There is limited data on optimal selection of patients in order to obtain the greatest therapeutic gain with the least toxicity. The aim of this study was to find and define groups of patients who would benefit most from this treatment in a real-world mCRC patient population. Methods: Consecutive patients with unresectable or metastatic colorectal cancer (mCRC) started treatment with FTD/TPI between 1/Sep/2019 and 31/Dec/2023. Clinical factors including age, gender, primary location of colorectal cancer, BRAF, RAS and MSI-H status, ECOG performance status, baseline CEA level, location of metastases, response to treatment and AEs occurrence were analyzed. Survival analyses were performed using the Kaplan-Meier method, Log-rank and chi-square tests were used for comparison between groups. Data cut-off was 31/Jan/2024. Results: 822 medical records of patients with mCRC were analyzed. In total 261 patients treated with FTD/TPI were enrolled. 204 (78%) patients were treated with FTD/TPI in 3rd line (L3) and 57 (22%) in the 4th line (L4). Patients with RASmt were statistically more numerous in the L3 group; no other statistically significant differences in baseline characteristics was found between L3 and L4 groups. Estimated median OS (mOS) was 10.2 and 14.4 months in L3 and L4 group, respectively; no statistical significance was found between them (p = 0.0866; HR = 1.34, Cl 95% 0.9-1.9). Estimated median PFS (mPFS) was 7.4 and 4.6 months in L3 and L4 group, respectively, and statistically significant differences in mPFS was found in the L3 group in comparison to L4 (p = 0.0079; HR = 0.65, Cl 95% 0.5-0.9). Disease progression (PD) was found in 187 (92%) and 50 (88%) patients in the L3 and L4 group, respectively. PD was most common reason for discontinuing therapy. Most frequent serious AEs of grade 3 or higher were diarrhea, neutropenia and weakness. There were no grade 5 AEs and toxicity rarely led to discontinuation of FTD/TPI therapy. 102 (39%) patients were qualified for next line sequential systemic treatment after L3 or L4. Conclusions: Patients with mCRC who were treated with FTD/TPI in the 3rd line had better PFS than patients treated in 4th line, but mOS was statistically non-significantly better in L4 than L3, which requires further analysis. FTD/TPI is an effective therapy in subsequent lines of treatment for mCRC patients with acceptable toxicity.

FOLFOXIRI/bevacizumab (bev) versus doublets/bev as initial therapy of unresectable liver-only, right-sided and/or RAS or BRAF mutated (mut) metastatic colorectal cancer (mCRC): An individual patient data-based pooled analysis of randomized trials.

e15563 Background: FOLFOXIRI/bev was associated with longer PFS and OS versus doublets/bev independently of the presence of liver-limited disease or not, and the secondary resection of metastatic lesions. Recently, in the CAIRO-5 study patients with liver-limited right-sided and/or RAS or BRAF mutated mCRC experienced no OS difference, but higher ORR, R0 resection rate, and longer PFS with the triplet/bev when compared with doublets/bev. Here we aim at providing an estimation of the efficacy and activity of FOLFOXIRI/bev over doublets/bev in patients with unresectable liver-only, right-sided and/or RAS or BRAF mut mCRC. Methods: We selected pts with liver-only, right-sided and/or RAS or BRAF mut mCRC, and treated with first-line doublets/bev or FOLFOXIRI/bev in four phase II or III randomized controlled trials (RCTs): TRIBE (NCT00719797), TRIBE2 (NCT02339116), CHARTA (NCT01321957), and STEAM (NCT01765582). Patients included in these RCTs were deemed initially unresectable according to a multidisciplinary evaluation and were not selected based on the potential conversion to resectability. We compared FOLFOXIRI/bev with doublets/bev in terms of PFS, OS, ORR, and R0 resection. Results: A total of 300 pts were eligible. The median age was 61 years and most of them had an ECOG performance status of 0 (83%) and synchronous metastases (91%). One hundred and thirty (43%) and 170 (57%) pts received doublets/bev and FOLFOXIRI/bev, respectively. Baseline characteristics were homogeneous between the two treatment groups. Pts receiving FOLFOXIRI/bev showed longer PFS (12.3 vs 10.3 months [mos] HR:0.75, p = 0.019) and a statistically not significant trend for better OS (29.1 vs 23.2 mos, HR:0.85, p = 0.253), than those treated with doublets/bev. FOLFOXIRI/bev was also associated with higher ORR (64% vs 53%, OR:1.54, p = 0.076) and no differences in R0 resection rate (27% vs 24%, OR:1.15, p = 0.696) was reported. No significant interaction was found between treatment effect and the achievement of R0 resection in terms of both PFS (Pinteraction:0.81) and OS (Pinteraction:0.53). Conclusions: As compared to doublets/bev, upfront FOLFOXIRI/bev provides a meaningful advantage to pts with initially unresectable, liver-only, right-sided and/or RAS or BRAF mut mCRC, in terms of activity and efficacy, thus corroborating the choice of this regimen as upfront treatment for these pts, regardless of the opportunity to achieve the R0 secondary resection of their liver metastatic lesions.

Explanatory Role of Conversion Surgery as a Mediator of the Mortality Risk Difference Between Patients With Unresectable Metastatic Colorectal Cancer Treated With First-Line Anti-EGFR Agents Versus Bevacizumab

IntroductionBevacizumab and antiepidermal growth factor receptor-blocking (anti-EGFR) agents plus chemotherapy are first-line therapies for metastatic colorectal cancer (mCRC). Conversion surgery may improve outcomes; however, the extent to which it explains the difference in mortality rates among treatments is unclear. Herein, we aimed to assess the effects of conversion surgery on survival outcomes of patients with unresectable mCRC treated with bevacizumab and anti-EGFR agents. Materials and methodsThis retrospective cohort study included patients with mCRC treated with bevacizumab and anti-EGFR agents as first-line therapy. We estimated the direct and indirect effects of treatments by comparing the mortality risk associated with targeted therapy type. Hazard ratios (HR) and the corresponding confidence intervals (CI) were estimated. Mediation analysis was used to estimate hazard ratio differences, and the proportion mediated. ResultsA total of 5,106 patients were included. The natural indirect effect of conversion surgery reduced mortality risk (HR: 0.95; 95% CI, 0.93-0.97), with a mediated proportion of 42% after propensity score adjustment. In subgroup analyses, KRAS wild-type (HR: 0.94; 95% CI: 0.91-0.97), left tumor sidedness (HR: 0.94; 95% CI, 0.91-0.96), and liver resection (HR: 0.95; 95% CI, 0.93-0.98) were associated with reduced risks of mortality. The controlled and total direct effects of targeted therapy were associated with reduced mortality risk in the anti-EGFR-treated group compared to those in the bevacizumab-treated group; however, this effect was not statistically significant. ConclusionConversion surgery may account for the difference in survival outcomes between users of the anti-EGFR agents and bevacizumab.

Abstract CT217: First-line durvalumab and tremelimumab with chemotherapy in RAS-mutated metastatic colorectal cancer: a phase 1b-2 trial

Abstract Metastatic colorectal cancer (mCRC) remains a difficult-to-treat disease. While patients with microsatellite instable metastatic colorectal cancer (mCRC) benefit from immune checkpoint blockade, chemotherapy with targeted therapies remains the only therapeutic option for microsatellite stable (MSS) tumors. The single arm, phase IB/II MEDITREME trial evaluated the safety and efficacy of durvalumab plus tremelimumab combined with mFOLFOX6 chemotherapy in first line, in 57 patients with RAS-mutant unresectable mCRC. Safety was the primary objective of phase IB; no safety issue was observed. The phase II primary objective of efficacy in terms of 3-month PFS in MSS patients was met, with 3-month PFS of 90.7% [95% CI: 79.2-96%]. For secondary objectives, response rate was 64.5%, median PFS was 8.2 months [95% CI: 5.9-8.6] and overall survival was not reached in MSS patients. We observed higher tumor mutational burden and lower genomic instability in responders. Integrated transcriptomic analysis underlined that high immune signature, and low epithelio-mesenchymal transition were associated with better outcome. Immunomonitoring showed induction of neoantigen and NY-ESO1 and TERT blood tumor specific T cell response, associated with better PFS. The combination of durvalumab-tremelimumab with mFOLFOX6 was tolerable with promising clinical activity in MSS mCRC. Clinicaltrials.gov identifier: NCT03202758. Citation Format: Marion Thibaudin, Jean-David Fumet, Emeric Limagne, Léa Hampe, Susy Daumoine, Valentin Derangère, Caroline Laheurte, Olivier Adotevi, Caroline Truntzer, François Ghiringhelli. First-line durvalumab and tremelimumab with chemotherapy in RAS-mutated metastatic colorectal cancer: a phase 1b-2 trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT217.

Modified FOLFOX6 plus bevacizumab with and without nivolumab for first-line treatment of metastatic colorectal cancer: phase 2 results from the CheckMate 9X8 randomized clinical trial

BackgroundStandard first-line therapies for metastatic colorectal cancer (mCRC) include fluoropyrimidine-containing regimens with oxaliplatin and/or irinotecan and a biologic agent. Immunotherapy may enhance antitumor activity in combination with standard therapies in...

Preliminary efficacy and safety of fruquintinib as maintenance therapy after first-line treatment in metastatic colorectal cancer (mCRC): A multicenter, randomized, open-label clinical trial (the FRONT study).

126 Background: Maintenance therapy and discontinuation of treatment are options to mCRC patients who response to first-line treatment. We conducted this study to evaluate the efficacy and safety of fruquintinib as maintenance therapy after first-line treatment for mCRC. Methods: This is an ongoing, multicenter, open-label, randomized clinical trial. Patients (pts) with unresectable right-sided mCRC or RAS-mutant left-sided mCRC, who hadn’t suffer disease progression after first-line standard treatment (chemotherapy with or without bevacizumab) for four to six months, were eligible. According to the protocol, 110 patients would be randomly assigned (2:1) to fruquintinib (FR) group (4mg once daily for 21 days, followed by 7 days off in 28 day cycles) or observation (OB) group via interactive web response system. The primary endpoint was progression-free survival (PFS). Results: Up to Aug 22, 2023, 28 and 14 patients had been enrolled in FR group and OB group, of whom the median age was 61 (44 to 73) vs. 66.5 (36 to 81), including 20 (71%) vs. 10 (71%) males, respectively. 26 (93%) vs. 11 (79%) patients were RAS-mutant. In the full analysis set (FAS), the median PFS were 5.26 (95% CI: 3.71-19.12) months and 2.99 (95% CI: 1.91-4.63) months (HR=0.36; p=0.0158). 25 and 13 pts from two groups received at least one response evaluation after baseline, respectively. The disease control rate (DCR) was 88.00% (22/25) vs. 53.85% (7/13) (OR=6.29, 95% CI: 1.31-36.7; p=0.0267). As to the per-protocol set (PPS), since 6 pts in FR group initiated with a lower dose (3mg), the number of patients was 22 vs. 14. The median PFS were 6.51 (95% CI: 3.88-19.12) months and 2.99 (95% CI: 1.91-4.63) months (HR=0.25; p=0.0061). The DCR was 89.47% (17/19) vs. 53.85% (7/13) (OR=7.29, 95% CI: 1.32-58.9; p=0.0331). The common AEs in FR group were hypertension, hand-foot syndrome, fatigue, rash, oral mucositis, and proteinuria, while AEs of grades≥3 were hand-foot syndrome, hypertension, oral mucositis, and proteinuria. Conclusions: Fruquintinib at a moderate dose level indicated better outcomes of PFS as a maintenance therapy after first-line therapy with acceptable toxicity for patients with mCRC. Clinical trial information: NCT04296019 .

Updated survival results of ALTER-C002: Anlotinib combined with CAPEOX as first-line treatment in RAS/BRAF wild-type unresectable metastatic colorectal cancer.

131 Background: Anlotinib is an oral multi-target tyrosine kinase inhibitor, mainly targeting VEGFR 1-3, FGFR 1-4, PDGFR a/b and c-kit. Previous trial had demonstrated that anlotinib monotherapy was effective and safe in advanced colorectal cancer. ALTER-C002 trial is an open-label, single-arm, phase II study, aimed to evaluate the efficacy and safety of anlotinib plus CAPEOX as first-line therapy in patients with RAS/ BRAF wild-type unresectable metastatic colorectal cancer (mCRC). The progression-free survival has been reported, preliminary results demonstrated significant antitumor activity and manageable toxicity, here we reported the overall survival results at the data cutoff of May 29, 2023. Methods: RAS/BRAF wild-type unresectable mCRC patients with no prior systemic treatment received anlotinib (12 mg p.o. qd, d1-d14, q3w), capecitabine (850 mg/m2 p.o., bid, d1-d14, q3w) and oxaliplatin (130 mg/m2 i.v., d1, q3w) for 6 cycles followed by anlotinib and capecitabine as maintenance therapy until disease progression. Tumor response was assessed every 6 weeks according to RECIST v1.1 by investigator. The primary endpoint was ORR, and secondary endpoints included safety, DCR, DOR and PFS. Results: From Nov 2019 to February 2021, 30 eligible patients were enrolled, of whom, median age was 60y (range, 32-72y), 26 (86.7%) had left colon or rectal cancer, and 25 (83.3%) had liver metastases. In previous reports, ORR, DCR, and median PFS were 76.7%, 93.3%, and 11.3 months, respectively. At a Median follow-up of 31.7 months (95% CI, 27.8-35.6), the median OS was 29.7 months (95% CI, 21.2-38.2), the 24-month OS rate was 55.0% (95%CI, 35.4-70.9%) and the 30-month OS rate was 40.6% (95%CI:21.6-58.9%). Conclusions: Anlotinib combined with oxaliplatin and capecitabine achieved considerable OS and showed potential efficacy as first-line therapy for mCRC with manageable toxicity profiles. Clinical trial information: NCT04080843 .

Assessing the effectiveness of targeted agents in adjuvant therapy for patients with metastatic colorectal cancer undergoing surgical resection: a retrospective cohort study.

Primary tumor resection and metastasectomy may be beneficial for many patients with metastatic colorectal cancer (mCRC). To assess the differences in postoperative survival outcomes between adjuvant therapy with chemotherapy alone and chemotherapy plus targeted agents (TAs). Retrospective cohort study. Patients with mCRC who underwent surgical resection for primary colorectal tumor and distant metastases and received adjuvant therapy from 1 January 2010 to 31 December 2017 were enrolled in the Taiwan Cancer Registry. We analyzed the overall survival of patients with resectable or initially unresectable mCRC who received adjuvant chemotherapy alone and chemotherapy plus TAs. We enrolled 1124 and 542 patients with resectable and initially unresectable mCRC, respectively. Adjuvant chemotherapy plus TAs and chemotherapy alone resulted in similar mortality rates among patients with resectable mCRC [adjusted hazard ratio (aHR) = 1.13; 95% confidence interval (CI), 0.93-1.36]; however, it marginally reduced the mortality rate among patients with initially unresectable mCRC who underwent conversion surgery after neoadjuvant therapy (aHR = 0.81; 95% CI, 0.62-1.06). The subgroup analysis of patients who received more than nine cycles of TAs preoperatively and anti-epidermal growth factor receptor agents revealed aHRs of 0.48 (95% CI, 0.27-0.87) and 0.33 (95% CI, 0.18-0.60), respectively. Adjuvant chemotherapy plus TAs may improve survival in patients with initially unresectable tumors who underwent conversion surgery following neoadjuvant therapy with TAs, especially in those who respond well to the targeted therapy. Our study underscores the importance of stratifying patients with mCRC based on tumor resectability when selecting the adjuvant therapy regimen.

Comparative effectiveness of primary tumor resection versus chemotherapy in patients with asymptomatic unresectable metastatic colorectal cancer: a retrospective cohort study using the target trial emulation framework.

Patients who undergo primary tumor resection (PTR) reportedly have significantly higher overall survival (OS) than those who do not undergo this procedure. However, this result is only evident in past retrospective studies, and clinical trial results did not show the same trend. Thus, it remains unclear whether primary tumor resection effectively increases survival in patients with metastatic colorectal cancer (mCRC) across different study designs. We compared the OS of patients with asymptomatic unresectable mCRC who underwent PTR with that of those who did not. This retrospective cohort study was designed to be a target trial emulation of a randomized controlled trial (RCT) that would have compared the effectiveness of PTR versus non-PTR in patients with asymptomatic unresectable mCRC from 2009 to 2017. A systematic review and meta-analysis were conducted to compare the efficacy of PTR and non-PTR in patients with mCRC, and corresponding results were compared. This cohort included 1,132 patients for a per-protocol analysis. The PTR group had non-significantly longer survival (adjusted hazard ratio: 0.70, 95% confidence interval: 0.62-1.01) than the non-PTR group in our cohort. A meta-analysis including five RCTs (1,016 patients) and our cohort found that the PTR group did not have a significantly lower mortality rate than the non-PTR group. The results of this cohort study and previous RCTs suggest that PTR is not associated with improved survival compared to systemic chemotherapy combined with targeted therapy among asymptomatic unresectable mCRC patients. Therefore, routine PTR is not recommended in these patients.

Triplet‐drug chemotherapy combined with anti‐EGFR antibody as an effective therapy for patients with initially unresectable metastatic colorectal cancer: a meta-analysis

The meta-analysis aimed to assess the clinical efficacy of chemotherapeutic triplet‐drug regimen combined with anti‐EGFR antibody in patients with initially unresectable metastatic colorectal cancer (mCRC). A systematic literature search was performed in PubMed Publisher. Studies evaluating FOLFOXIRI combine with panitumumab or cetuximab as the therapy for initially unresectable mCRC were included. The primary outcome was objective response rate (ORR) and rate of R0 resections. The secondary outcomes included overall survival (OS), progression-free survival (PFS), and grades 3 or 4 adverse events. R software (version 4.0.2) and RevMan (version 5.3) were used to analyze the extracted data. The studies included were published between 2010 and 2021, involving four single-arm phase II trials and two randomized phase II trials. A total of 6 studies with 282 patients were included. The data showed a significant benefit for the FOLFOXIRI + anti-EGFR antibody arm compared with FOLFOXIRI arm (RR 1.33; 95% CI, 1.13–1.58; I2 = 0%, P < 0.05). The pooled ORR and pooled rate of R0 resection in patients who receiving FOLFOXIRI + anti-EGFR antibody were 85% (95% CI, 0.78–0.91; I2 = 58%) and 42% (95% CI, 0.32–0.53; I2 = 62%), respectively. The range of median PFS between all the six studies was 9.5–15.5 months, with weighted pooled median PFS mean 11.7 months. The range of median OS between all the four studies was 24.7–37 months, with weighted pooled median PFS mean 31.9 months. The common grades 3 and 4 adverse events were diarrhea and neutropenia. Our findings show that triplet-drug chemotherapy (FOLFOXIRI) combined with anti-EGFR antibody (panitumumab or cetuximab) represents a very effective therapeutic combination associated with a significant ORR and R0 rection rate for patients with molecularly unselected and surgically unresectable metastatic CRC.

Maintenance Therapy With Cetuximab After FOLFIRI Plus Cetuximab for RAS Wild-Type Metastatic Colorectal Cancer

The optimal maintenance strategy after induction chemotherapy with anti-epidermal growth factor receptor antibody for patients with RAS wild-type metastatic colorectal cancer (mCRC) remains to be debated. To evaluate the efficacy and safety of maintenance therapy with single-agent cetuximab after FOLFIRI (leucovorin [folinic acid], fluorouracil, and irinotecan) plus cetuximab induction therapy. The TIME (Treatment After Irinotecan-Based Frontline Therapy: Maintenance With Erbitux]) (PRODIGE 28 [Partenariat de Recherche en Oncologie Digestive]-UCGI 27 [UniCancer GastroIntestinal Group]) phase 2 noncomparative, multicenter randomized clinical trial was conducted from January 15, 2014, to November 23, 2018, among 139 patients with unresectable RAS wild-type mCRC. The cutoff date for analysis was July 21, 2022. After first-line induction therapy with 8 cycles of FOLFIRI plus cetuximab, patients without disease progression were randomized (1:1) to biweekly maintenance with cetuximab or observation. On disease progression, the same induction regimen was recommended for 16 weeks followed by further maintenance with cetuximab or observation until disease progression under the full induction regimen. The primary end point was the 6-month progression-free rate from randomization. Analysis was performed on an intention-to-treat basis. An exploratory biomolecular analysis, using next-generation sequencing, investigated the putative prognostic value of the tumor mutation profile. Of 214 patients enrolled (141 men [65.9%]; median age, 67 years [range, 23-85 years]), 139 were randomized to receive cetuximab (n = 67; 45 men [67.2%]; median age, 64 years [range, 34-85 years]) or to be observed (n = 72; 50 men [69.4%]; median age, 68 years [23-85 years]). The 6-month progression-free rate was 38.8% ([26 of 67] 95% CI, 27.1%-51.5%) in the cetuximab group and 5.6% ([4 of 72] 95% CI, 1.5%-13.6%) in the observation group. At a median follow-up of 40.5 months (95% CI, 33.6-47.5 months), median progression-free survival (PFS) from randomization was 5.3 months (95% CI, 3.7-7.4 months) in the cetuximab group and 2.0 months (95% CI, 1.8-2.7 months) in the observation group. Median overall survival (OS) was 24.8 months (95% CI, 18.7-30.4 months) in the cetuximab group and 19.7 months (95% CI, 13.3-24.4 months) in the observation group. In an exploratory multivariate analysis, any tumor-activating mutation in the mitogen-activated protein kinase (MAPK) pathway genes was associated with shorter PFS from randomization regardless of treatment group (hazard ratio, 1.63 [95% CI, 1.01-2.62]; P = .04). The most frequent grade 3 or 4 treatment-related toxic effect in the cetuximab group during maintenance therapy was rash (8 of 67 [11.9%]). The randomized clinical trial did not meet its primary end point but suggests clinically meaningful PFS and OS benefits associated with cetuximab maintenance therapy. However, maintenance cetuximab or treatment breaks after first-line combination FOLFIRI-cetuximab therapy seems inappropriate for patients with MAPK-mutated independently of the side of primary tumor. A more complete assessment of MAPK pathway mutations warrants further investigation to the refine treatment strategy for patients with RAS wild-type mCRC. ClinicalTrials.gov Identifier: NCT02404935.

Sintilimab plus bevacizumab, oxaliplatin and capecitabine as first-line therapy in RAS-mutant, microsatellite stable, unresectable metastatic colorectal cancer: an open-label, single-arm, phase II trial

Microsatellite stable (MSS) and RAS-mutant metastatic colorectal cancer (mCRC) patients are characterized by an immunosuppressive microenvironment and a low response rate to immunotherapy. Chemotherapy and anti-angiogenesis therapy have been reported to potentially promote immunotherapy response. This study aims to assess the preliminary anti-tumor activity and safety of sintilimab plus bevacizumab, oxaliplatin and capecitabine as a treatment option for patients with RAS-mutant MSS mCRC. This study was an open-label, single-arm, phase II trial in China. Patients with unresectable, RAS-mutant and MSS metastatic colorectal adenocarcinoma received treatment by intravenous sintilimab (200mg, day 1) plus bevacizumab (7.5mg/kg, day 1), oxaliplatin (135mg/m2, day 1) and oral capecitabine (1g/m2, day 1-14) in each 21-day cycle. The primary endpoints included objective response rate (ORR) and adverse events. Biomarker analysis was performed to identify potential predictors of good response to treatment. This study is registered with ClinicalTrials.gov, number NCT04194359. Between April 2021 and December 2021, 25 patients were enrolled. Two (8%) patients showed complete response (CR), 19 (76%) had partial response (PR) and 4 (16%) presented with stable disease. ORR reached 84% (95% CI, 63.9-95.5) and the disease control rate was 100% (95% CI, 86.3-100). The median progression-free survival (PFS) was 18.2 months for the full analysis set. The most common treatment-related adverse events (TRAEs) in all grades were anemia (21/25, 84%), neutropenia (20/25, 80%), and hand-foot syndrome (14/25, 56%). The most frequent grade 3 or 4 TRAEs were neutropenia (3/25, 12%) and increased alanine transaminase (2/25, 8%). No grade 5 adverse events occurred. In the exploration of biomarkers, 5 patients could be characterized as TTN/OBSCN "double-hit" after treatment, and the copy number variants burden was significantly decreased in tumor tissues after treatment compared with the baseline. Nanostring panel RNA sequencing analysis indicated a better tumor immune microenvironment cell infiltration in CR/PR patients compared with non-CR/PR patients as well as the PFS-long (≥12.5 months) group compared with the PFS-short group. Combination treatment with sintilimab plus bevacizumab, oxaliplatin and capecitabine as first-line treatment demonstrated a promising antitumor activity and a manageable safety profile in RAS-mutant, MSS and unresectable mCRC. Exploratory biomarker assessment analysis showed that some RAS-mutant and MSS patients changed into "immune-hot" subtype after the treatment. This study was supported by the Key R&D Program of Zhejiang Province (2021C03125 to Ying Yuan), the National Natural Science Foundation of China (81872481 to Ying Yuan, 82072624 to Kefeng Ding), the Fundamental Research Funds for the Central Universities (No. 226-2022-00009 to Kefeng Ding), and the Zhejiang Provincial Natural Science Foundation of China (No. LY22H160024 to Hanguang Hu).

CDX2 Is a Prognostic Biomarker for Unresectable Metastatic Colorectal Cancer.

Colorectal cancer (CRC) with reduced expression of the homeobox transcription factor CDX2, a master gene essential for the development and maintenance of the intestinal tract, is known as a poor prognosis subtype of CRC. The recurrence rate is high in patients with CDX2low CRC. However, the prognostic significance of CDX2 in advanced CRC is unclear. This study aimed to elucidate the prognostic significance of CDX2 in unresectable metastatic CRC (mCRC). Twenty-nine patients with unresectable mCRC who underwent primary site resection at the Kobe University Hospital during a 6-year period from January 2008 to January 2015 were included. The tissues from those patients were immunohistochemically stained with anti-CDX2 antibody (clone: CDX2-88). The patients were divided into CDX2high CRC group and CDX2low CRC group and their prognoses were analyzed. There were no clear differences in background between the two groups. A low CDX2 expression was associated with reduced overall survival (37.67 months vs. 25.32 months, p=0.03) and tended to associate with reduced progression-free survival (17.4 months vs. 12.9 months, p=0.37). Two patients received chemotherapy after resection of the primary lesion and obtained pathological complete response. CDX2 expression might be a possible prognostic biomarker for unresectable mCRC.

Early low blood MALT1 expression levels forecast better efficacy of PD‑1 inhibitor‑based treatment in patients with metastatic colorectal cancer.

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) modulates colorectal cancer (CRC) malignant behaviors and tumor immune escape. The present study aimed to explore the association of MALT1 with treatment response and survival time among patients with metastatic CRC (mCRC) after programmed cell death protein-1 (PD-1) inhibitor-based treatment. MALT1 from the blood samples of 75 patients with unresectable mCRC receiving PD-1 inhibitor-based treatment at baseline and after 2-cycle treatment, as well as 20 healthy controls (HCs), was detected by reverse transcription-quantitative PCR. In the patients with mCRC, the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS) were calculated. MALT1 expression was elevated in patients with mCRC compared with that in HCs (P<0.001). In patients with mCRC, MALT1 expression was positively correlated with multiple (vs. single) metastasis (P=0.032) and peritoneum metastasis (P=0.029). MALT1 levels before treatment were decreased in ORR patients vs. non-ORR patients (P=0.043) and in DCR patients vs. non-DCR patients (P=0.007). Additionally, MALT1 expression was reduced after treatment compared with that before treatment (P<0.001). Meanwhile, MALT1 expression after treatment was notably decreased in ORR patients vs. non-ORR patients (P<0.001) and in DCR patients vs. non-DCR patients (P<0.001). Furthermore, a low MALT1 level before treatment was associated with longer PFS (P=0.030) and OS (P=0.025) times. Decreased MALT1 expression after treatment and a decline in MALT1 expression of >30% after treatment (ratio to MALT1 before treatment) (both P≤0.001) presented more significant associations with prolonged PFS and OS times. In conclusion, early low levels of blood MALT1 during therapy may predict an improved response to PD-1 inhibitor-based treatment and survival time in patients with mCRC.

FOLFOXIRI plus bevacizumab and atezolizumab as upfront treatment of unresectable metastatic colorectal cancer (mCRC): Updated and overall survival results of the phase II randomized AtezoTRIBE study.

3500 Background: AtezoTRIBE (NCT03721653) is a phase II randomized trial in which unresectable mCRC pts were randomized 1:2 to 1st-line FOLFOXIRI/bev [arm A] or FOLFOXIRI/bev/atezo [arm B]. Adding atezo to FOLFOXIRI/bev was safe and improved PFS (primary endpoint), with a modest benefit also among pts with pMMR tumors. Subgroup analyses suggest that TMB and Immunoscore IC (IS IC) -an IHC biomarker measuring CD8 and PD-L1 cell densities and their proximity- may identify pts with pMMR tumors deriving benefit from adding atezo to FOLFOXIRI/bev. Methods: The study had 85% power to detect a HR for PFS (time from randomization to 1st PD or death [PD1]) of .66 in favor of arm B with 1-sided α error of .10. Secondary endpoints included PFS2 (time from randomization to PD on any treatment given after PD1 or death [PD2]), 2nd PFS (time from PD1 to PD2), and OS. MMR, TMB, IS IC were correlated to clinical outcome. Results: 218 pts (arm A/B:73/145) were enrolled. Main pts’ characteristics were right-sided 44%/45%, RAS mut 71%/74%, BRAF mut 14%/8%, dMMR 7%/6%, high TMB 10%/12%, high IS IC 32%/32%. At a median follow-up of 37.0 mos, 175 (80%, arm A/B: 64/111) PD1, 150 (69%, arm A/B: 53/97) PD2, and 118 (54%, arm A/B: 43/75) OS events were collected. Out of 175 pts with a PD1 event, 135 (77%, arm A/B:50/85) received a subsequent treatment; among them, 121 pts (arm A/B: 43/78) had a PD2 event. PFS, PFS2, 2nd PFS and OS results in the intention-to-treat (ITT) population and the pMMR group are listed in the Table. In the ITT population, significant interactions between treatment and MMR status (Pint .011), TMB (Pint .008), and IS IC (Pint .037) were reported in terms of PFS. Only IS IC was associated with a differential OS benefit (Pint .065), with pts bearing IS IC-high tumors deriving benefit from adding atezo (HR 0.43, 95%CI 0.19-1.00), differently than those with IS IC-low tumors (HR 1.09, 95%CI 0.65-1.83). In the pMMR group, significant interactions between treatment and TMB and IS IC were reported in terms of PFS (Pint .016 and .051, respectively) and OS (Pint .043 and .063, respectively). Pts bearing IS IC-high tumors derived higher OS benefit from adding atezo (HR 0.44, 95%CI 0.19-1.03), than those with IS IC-low tumors (HR 1.15, 95% CI 0.67-1.97). Conclusions: Pts with IS IC-high and/or TMB high pMMR mCRC seem to derive a survival benefit from adding atezo to FOLFOXIRI/bev as upfront treatment. These findings deserve confirmation in a properly designed phase III trial. Clinical trial information: NCT03721653 . [Table: see text]

Intraarterial chemotherapy of liver metastases of colorectal cancer. Experience of National Cancer Institute of Ukraine.

e15619 Background: Liver - is the most often site of colorectal cancer metastases. Although surgical resection of primary tumor and liver metastases is the most radical type of treatment, only 10-25% of patients are eligible for this approach. Our aim was to evaluate efficacy of intraarterial chemotherapy for patients with primary unresectable metastatic colorectal cancer (mCRC) to improve prognosis and overall response for treatment. Methods: records of 73 patients with primary unresectable mCRC, who undergone catheterization of liver artery and received intraartetial chemotherapy (with 5-FU) in period 2008-2018 years at the Clinic of National Cancer Institute (Ukraine). Results: the figure of overall response: 57.5% (n = 42) - partial response, 8.2% (n = 6) - complete radiological response, 12.3% (n = 9) - stable disease, 21.9% (n = 16) - chemoresistant tumor. 46.6% (n = 34) of patient undergone resection of previously unresectable liver metastases. In 4.1% (n = 3) complete histological response was estimated. Surgical mortality and morbidity rate were 1.3% and 6.8% respectively. Cause of postoperative mortality was lung embolism, complications included bacterial infections and hemorrhage in postoperative period. Main reason for inability to perform operations were post chemotherapeutic toxicity, which did not resolved on optimal terms for operation. The overall 5-year survival rate was 29.4% in group who undergone resection and 17.9% in group, were patients were not radically operated (p &lt; 0.05). Conclusions: catheterization of liver artery with further intraarterial chemotherapy can potentially convert unresectable metastases into resectable, therefore improving treatment results and overall survival.

SO-28 FOLFOXIRI plus bevacizumab and atezolizumab as upfront treatment of unresectable mCRC patients: Updated and overall survival results of the phase II randomized AtezoTRIBE study

SO-28 FOLFOXIRI plus bevacizumab and atezolizumab as upfront treatment of unresectable mCRC patients: Updated and overall survival results of the phase II randomized AtezoTRIBE study