Unresectable Colorectal Cancer Research Articles

FOLFOXIRI for First-Line Treatment of Unresectable Colorectal Cancer with Liver Metastases in a Resource-Limited Setting.

FOLFOXIRI is a standard treatment for unresectable colorectal cancer (CRC) liver metastases. However, limited data exists on its safety and effectiveness in low-to-middle-income countries (LMICs). This prospective study addresses this gap in a Vietnamese LMIC setting. We enrolled 92 patients with unresectable CRC liver metastases between 2022 and 2023. All patients received FOLFOXIRI every 2 weeks, with routine G-CSF prophylaxis to prevent neutropenia. A multidisciplinary team (MDT) assessed diagnoses and treatment responses. Outcomes were R0/R1 resection rate, progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), adverse events (AEs), and recurrence-free survival (RFS) for surgical patients. The median patient age was 56 years, with a male predominance (70.7%). The primary tumors were located in the left colon (42.4%), rectum (37%), and right colon (20.7%). Thirty-two patients (34.8%) experienced severe (grade 3 or higher) AEs, with thrombocytopenia (13.1%) and anemia (9.8%) being the most frequent. Most patients (72/87, 82.9%) achieved a partial response. The ORR and DCR were 85.1% and 95.4%, respectively. Fifty-seven patients (62%) achieved resectability, and 54 (58.7%) underwent radical surgery. The R0/R1 resection rate was 88.9%. The median PFS and OS for all patients were 13 and 22 months, respectively. The median RFS of surgical patients was 14 months. FOLFOXIRI improves the response rates, R0/R1 resection rates, and survivals for patients with CRC liver metastases. Future research is necessary to improve the prognosis of patients while minimizing toxicities. NCT05362825 dated 5 May 2022.

Posthepatectomy Liver Failure in Patients with Splenomegaly Induced by Induction Chemotherapy for Colorectal Liver Metastases.

With advances in chemotherapy, conversion surgery is often performed for initially unresectable colorectal cancer liver metastasis (CLM). However, unexpected posthepatectomy liver failure (PHLF) is sometimes associated with chemotherapy-associated liver injuries following long-term chemotherapy. We aimed to identify predictive factors for PHLF after conversion surgery for initially unresectable CLM. We retrospectively identified 774 consecutive patients who underwent initial liver resections for histologically confirmed CLMs between 2010 and 2019 at our institute. We enrolled 107 patients with initially unresectable CLMs. Clinicopathological characteristics were evaluated to determine their association with PHLF. Logistic regression analysis was performed to analyze the predictors of PHLF. Among the 107 patients, PHLF occurred in 15 cases (14%). Multivariate analysis revealed that splenomegaly during preoperative chemotherapy (> 135%) was an independent risk factor for PHLF (P = 0.002; odds ratio 14.30; 95% confidence interval 2.69-76.08). In the analysis limited to the splenomegaly group, lower platelet counts, increased blood loss and operative times, and large liver resection areas (> 100 cm2) were significant risk factors for PHLF (P = 0.018, 0.043, 0.020, and 0.024, respectively). Among them, a liver resection area > 100 cm2 can be calculated preoperatively and correlate with a complex hepatectomy. These findings could help predict PHLF after conversion surgery and induction chemotherapy for initially unresectable CLMs. Careful decisions, including detailed procedures and timing of hepatectomy, should be made before conversion hepatectomy in patients who develop splenomegaly after induction chemotherapy and require complex hepatectomies with a large liver resection area.

Population Pharmacokinetic Analysis of Tucatinib in Healthy Participants and Patients with Breast Cancer or Colorectal Cancer.

Tucatinib is a highly selective, oral, reversible, human epidermal growth factor receptor 2 (HER2)-specific tyrosine kinase inhibitor. Tucatinib is approved at a 300-mg twice-daily dose in adults in combination with trastuzumab and capecitabine for advanced HER2-postitive (HER2+) unresectable or metastatic breast cancer and in combination with trastuzumab for RAS wild-type HER2+ unresectable or metastatic colorectal cancer. This study sought to characterize the pharmacokinetics (PK) and assess sources of PK variability of tucatinib in healthy volunteers and in patients with HER2+ metastatic breast or colorectal cancers. A population pharmacokinetic model was developed based on data from four healthy participant studies and three studies in patients with either HER2+ metastatic breast cancer or metastatic colorectal cancer using a nonlinear mixed-effects modeling approach. Clinically relevant covariates were evaluated to assess their impact on exposure, and overall model performance was evaluated by prediction-corrected visual predictive checks. A two-compartment pharmacokinetic model with linear elimination and first-order absorption preceded by a lag time adequately described tucatinib pharmacokinetic profiles in 151 healthy participants and 132 patients. Tumor type was identified as a significant covariate affecting tucatinib bioavailability and clearance, resulting in a 1.2-fold and 2.1-fold increase in tucatinib steady-state exposure (area under the concentration-time curve) in HER2+ metastatic colorectal cancer and HER2+ metastatic breast cancer, respectively, compared with healthy participants. No other covariates, including mild renal or hepatic impairment, had an impact on tucatinib pharmacokinetics. The impact of statistically significant covariates identified was not considered clinically meaningful. No tucatinib dose adjustments are required based on the covariates tested in the final population pharmacokinetic model. NCT03723395, NCT03914755, NCT03826602, NCT03043313, NCT01983501, NCT02025192.

506O Evaluation of risk of disease progression in first-line therapy of unresected metastatic colorectal cancer to guide intervals of radiological assessment: An analysis of eleven randomized trials by AIO and GONO

506O Evaluation of risk of disease progression in first-line therapy of unresected metastatic colorectal cancer to guide intervals of radiological assessment: An analysis of eleven randomized trials by AIO and GONO

Contrast-enhanced intraoperative ultrasound improved hepatic recurrence-free survival in initially unresectable colorectal cancer liver metastases

BackgroundWe aimed to evaluate the role of Contrast-enhanced intraoperative ultrasound (CE-IOUS) with perfluorobutane microbubbles (Sonazoid) in improving the prognosis of patients with unresectable colorectal cancer liver metastases (CRLM). MethodsA total of 130 Patients with unresectable CRLM who underwent curative hepatic resection at our institute were retrospectively analyzed. Of these 130 enrolled patients, 67 underwent intraoperative ultrasound alone (IOUS group); 63 underwent additional CE-IOUS and IOUS (CE-IOUS group). Normalized inverse probability treatment weighting (IPTW) was employed to balance baseline characteristics between groups. Hepatic recurrence-free survival (HRFS) and overall survival (OS) were compared. ResultsThe treatment strategy was altered in 25 patients (25/63, 39.9%) due to the additional use of CE-IOUS. After applying IPTW, the CE-IOUS group exhibited a significantly lower rate of hepatic recurrence (hazard ratio [HR], 0.55; 95% confidence interval [CI] 0.32–0.95; P = 0.032). Subgroup analysis showed that CE-IOUS provided a significant benefit over IOUS in patients with bilobar liver metastases (P = 0.007), or with a number of live tumors < 3 (P = 0.021), or without DLM (P = 0.018), or with extrahepatic metastasis (P = 0.034), or with a minimum of 6 cycles of systemic therapy (P = 0.03). ConclusionsCE-IOUS is necessary for unresectable CRLM after preoperative chemotherapy, as it enhances detection accuracy and improves the prognosis of unresectable CRLM patients.

Baseline hepatobiliary MRI for predicting chemotherapeutic response and prognosis in initially unresectable colorectal cancer liver metastases

PurposeTo evaluate the performance of hepatobiliary MRI parameters as predictors of clinical response to chemotherapy in patients with initially unresectable colorectal cancer liver metastases (CRLM).MethodsEighty-five patients with initially unresectable CRLM were retrospectively enrolled from two hospitals and scanned using gadobenate dimeglumine-enhanced MRI before treatment. Therapy response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Conventional parameters (i.e., signal intensity [SI]) and radiomics features of portal venous phase (PVP) and hepatobiliary phase (HBP) images were analyzed between the responders and non-responders. Next, the combined model was constructed, and the area under the receiver operating characteristic (ROC) curve (AUC) was calculated. The relationship between the combined model and progression-free survival (PFS) was analyzed using Cox regression.ResultsOf the 85 patients from two hospitals, 42 were in the response group, and 43 were in the non-response group. Upon conducting five-fold cross-validation, the normalized relative enhancement (NRE) of CRLM during the PVP yielded an AUC of 0.625. Additionally, a radiomics feature derived from the tumor area in the HBP achieved an AUC of 0.698, while a separate feature extracted from the peritumoral region in the HBP recorded an AUC of 0.709. The model that integrated these three features outperformed the individual features, achieving an AUC of 0.818. Furthermore, the combined model exhibited a significant correlation with PFS (P < 0.001).ConclusionThe combined model, based on baseline hepatobiliary MRI, aids in predicting chemotherapeutic response and PFS in patients with initially unresectable CRLM.

Patient Satisfaction Survey on Portable Infusion Pumps for Colorectal Cancer Chemotherapy: Hard-Shelled or Soft-Shelled?

Elastomeric infusion pumps are widely used in colorectal cancer chemotherapy. However, no studies to date have investigated patient preferences regarding different infusion pump types. Twenty patients with unresectable colorectal cancer undergoing chemotherapy were initially treated with a portable hard-shelled continuous infusion pump, followed by a soft-shelled continuous infusion pump. The respondents used a numerical rating scale (0-10) to rate their comfort when using each pump, their ease of carrying it, the pump size and shape, its weight, their ease of reading its memory, and their overall satisfaction with it. They were then asked to determine which pump they would ultimately prefer. In terms of comfort, significantly higher user satisfaction was reported for the soft-shelled pump during the daytime and when going out (P < 0.001, P < 0.001, respectively). For pump portability, size, shape, and weight, the soft-shelled type also outperformed the hard-shelled one (P < 0.001, P=0.0011, P < 0.001, respectively). However, the hard-shelled pump scored significantly better in terms of ease of viewing memory (P < 0.001). Overall satisfaction was significantly higher for the soft-shelled pump than the hard-shelled type (P=0.0095). Finally, 13 patients (65%) indicated that they would prefer a soft-shelled pump for their next treatment, while only one patient (5%) preferred a hard-shelled alternative. A preference for soft-shelled pump was observed, particularly in female patients and those with a body mass index of < 22 kg/m2. The selection of portable elastomeric infusion pumps should consider the preferences of patients with colorectal cancer, as these devices have the potential to enhance their quality of life.

Prognosis and predictive factors of conversion surgery for initially unresectable advanced colorectal cancer

PurposeThe aim of this study was to report the outcomes of conversion surgery for initially unresectable advanced colorectal cancer and to identify factors that enable successful conversion surgery.MethodsWe compared the outcomes of patients with colorectal cancer with distant metastases, including extrahepatic metastases, who underwent upfront surgery, neoadjuvant chemotherapy, conversion surgery, and chemotherapy only at our department from 2007 to 2020. In addition, factors influencing the achievement of conversion surgery in patients who were initially unresectable were examined in univariate and multivariate analyses.ResultsOf 342 colorectal cancer patients with distant metastases treated during the study period, 239 were judged to be initially unresectable, and 17 (conversion rate: 7.1%) underwent conversion surgery. The prognosis for the conversion surgery group was better than that of the chemotherapy only group but worse than that of the upfront surgery group. In the conversion surgery group, the recurrence-free survival after resection was significantly shorter than that upfront surgery group and neoadjuvant chemotherapy group, and no patients have been cured. Among patients who were initially unresectable, left-sided primary cancer and normal CA19-9 level were identified as independent factors contributing to the achievement of conversion surgery in a multivariate analysis.ConclusionsAlthough relapse after conversion surgery is common, and no patients have been cured thus far, overall survival was better in comparison to patients who received chemotherapy only. Among unresectable cases, patients with left-sided primary cancer and normal CA19-9 levels are likely to be candidates for conversion surgery.

A phase II trial of UGT1A1 genotype-guided FOLFIRI plus bevacizumab as first-line therapy for advanced, unresectable colorectal cancer.

FOLFIRI is a standard regimen for metastatic colorectal cancer (mCRC). We hypothesized that a pharmacogenomic-directed strategy where more efficient irinotecan metabolizers (UGT1A1 *1/*1 homozygotes and *1/*28 heterozygotes) receive higher-than-standard irinotecan doses would improve progression-free survival (PFS) compared to non-genotype selected historical controls with acceptable toxicity. In this phase II multicenter study irinotecan dosing in first-line FOLFIRI and bevacizumab for mCRC was based on UGT1A1 genotype with *1/*1, *1/*28, and *28/*28 patients receiving 310 mg/m2, 260 mg/m2, and 180 mg/m2, respectively. Primary endpoint was PFS. Secondary endpoints were investigator and patient-reported adverse events, and estimation of overall survival (OS). One-hundred patients were enrolled with 91 evaluable for PFS and 83 evaluable for best response. Median PFS was 12.5 months (90% CI 10.9, 15.4), shorter than the anticipated alternative hypothesis of 14 months. PFS by genotype was 12.5 months (90% CI 10.9, 17.4) for *1/*1, 14.6 months (90% CI 11.8, 17.5) for *1/*28, and 6 months (90% CI 2.3, 7.7) for *28/28, respectively. OS was 24.5 months (90% CI 19.1, 30.7) and by genotype was 26.5 (90% CI 19.1, 32.9), 25.9 (90% CI 17.6, 37.7), and 13.4 (90% CI 2.3, 20.5) months for *1/*1, *1/*28, and *28/*28, respectively. G3/4 toxicity was similar between all subgroups, including diarrhea and neutropenia. A pharmacogenomic-directed irinotecan strategy improved PFS in the *1/*1 and *1/*28 genotypes with higher rates of neutropenia and similar rates of diarrhea compared to expected with standard FOLFIRI dosing. However, improvements in response rate and PFS were modest. This strategy should not change standard practice for mCRC patients in the first-line setting.

Targeted Treatment against Cancer Stem Cells in Colorectal Cancer.

The cancer stem cell (SC) theory proposes that a population of SCs serves as the driving force behind fundamental tumor processes, including metastasis, recurrence, and resistance to therapy. The standard of care for patients with stage III and high-risk stage II colorectal cancer (CRC) includes surgery and adjuvant chemotherapy. Fluoropyrimidines and their combination with oxaliplatin increased the cure rates, being able to eradicate the occult metastatic SC in a fraction of patients. The treatment for unresectable metastatic CRC is based on chemotherapy, antibodies to VEGF and EGFR, and tyrosine-kinase inhibitors. Immunotherapy is used in MSI-H tumors. Currently used drugs target dividing cells and, while often effective at debulking tumor mass, these agents have largely failed to cure metastatic disease. SCs are generated either due to genetic and epigenetic alterations in stem/progenitor cells or to the dedifferentiation of somatic cells where diverse signaling pathways such as Wnt/β-catenin, Hedgehog, Notch, TGF-β/SMAD, PI3K/Akt/mTOR, NF-κB, JAK/STAT, DNA damage response, and Hippo-YAP play a key role. Anti-neoplastic treatments could be improved by elimination of SCs, becoming an attractive target for the design of novel agents. Here, we present a review of clinical trials assessing the efficacy of targeted treatment focusing on these pathways in CRC.

SWOG S2107: Randomized phase II trial of encorafenib and cetuximab with or without nivolumab for patients with previously treated, microsatellite stable, BRAFV600E metastatic and/or unresectable colorectal cancer.

TPS3640 Background: Patients with microsatellite stable (MSS), BRAFV600E metastatic colorectal cancer (mCRC) experience poor survival outcomes. Second-line treatment with the BRAF inhibitor encorafenib (E) and anti-EGFR antibody cetuximab (C) is an approved treatment combination, with overall response rate (ORR) of 20% and median progression-free survival (PFS) of 4.1 months. Anti-PD-1 antibodies like nivolumab (N) are ineffective as monotherapy for patients with MSS, BRAFV600E mCRC. In preclinical models of MSS, BRAFV600E CRC, inhibition of BRAF and EGFR induces loss of expression of mismatch repairs genes and promotes a microsatellite instability-high phenotype, which may prime these tumors for response to immunotherapy. In support of these findings, a single-institution clinical trial of E + C + N for 26 patients with MSS, BRAFV600E mCRC reported an ORR of 50% and median PFS of 7.2 months. We hypothesize that the addition of N to E + C will improve median PFS for patients with MSS, BRAFV600E mCRC. Methods: In this prospective phase II clinical trial (N=84), patients with previously treated MSS, BRAFV600E mCRC are randomized 2:1 into 2 arms, respectively: experimental treatment (E + C + N) or standard treatment (E + C). No prior BRAF, EGFR, or immunotherapy agents are allowed. All patients receive E (300 mg PO daily) and C (500 mg/m2 IV every 14 days), and patients in the experimental arm receive N (480 mg IV every 28 days). The primary endpoint is PFS. Secondary endpoints include overall survival, best overall response, duration of response, and safety/tolerability. Using a one-sided α= .10 and power 80%, we target an improvement in median PFS from 4.2 to 7.3 months (hazard ratio 0.57). Additional patient specimens will be collected for exploratory correlative research. As of 2/2024, 50 of 84 planned participants have been enrolled. Clinical trial information: NCT05308446 .

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.

Phase Ib/II trial of hepatic arterial infusion chemotherapy in combination with fruquintinib for refractory unresectable colorectal cancer liver metastases.

3561 Background: Hepatic arterial infusion chemotherapy (HAIC), a highly efficient local therapy for patients with colorectal liver metastases (CRLM), is supposed to have a synergetic effect when it is in combination with a systemic therapy. The aim of this study was to determine the recommended phase 2 dose (PR2D) of fruquintinib combine with HAIC and evaluate efficacy and safety in expansion cohort of patients with CRLM. Methods: This open-label, single-arm, phase Ib/II study (NCT05406206) enrolled patients with CRLM who had received at least two prior lines of treatment. In the dose-finding phase, based on a standard 3+3 design, patients were treated with HAIC involving oxaliplatin (85 mg/m2) and 5-FU (2000 mg/m2) on day 1 and 2 every 4 weeks, alongside fruquintinib (3mg, 4mg, 5mg, d3-23, q4w, respectively) until unacceptable toxicities, progressive disease, or death occurred. In the dose-expansion phase, patients received HAIC and RP2D of fruquintinib determined in the dose-escalation phase. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included RP2D, objective response rate (ORR; RECIST 1.1), disease control rate (DCR), overall survival (OS) and safety. Results: As of data cutoff date on January 30, 2024, a total of 30 patients were enrolled. 9 (30.0%) patients were female, and the mean age was 56 years, 22 (73.3%) patients were RAS/BRAF mutant. During the dose-escalation phase, 15 patients were enrolled, with 3, 6, and 6 patients receiving doses of 3 mg, 4 mg, and 5 mg, respectively. Only one dose-limiting toxicity occurred in a patient of 4 mg level (G3 hypertension failed to control with antihypertensive treatment within 7 days). RP2D of fruquintinib was established as 5 mg. Fifteen patients were evaluable for efficacy, with best response of pathological complete response in 1 patient, partial response in 5 patients and stable disease in 6 patients, yielding an ORR of 40.0% and DCR of 80.0%. Median hepatic-PFS and median PFS was 6.8 months (95% CI, 5.890-7.710) and 5.9 months (95% CI, 3.576-8.224), respectively. The median OS reached 15.0 months (95% CI, 8.671-21.329). 7 (23.3%) patients experienced G3/4 treatment-related adverse events (TRAEs). The most common TRAEs of all grades were voice alteration, hypertension, abdominal pain and hand-foot syndrome. Conclusions: The combination of HAIC and fruquintinib showed a manageable safety profile and survival benefit of heavily treated CRLM patient. Clinical trial information: NCT05406206 .

Unanticipated pathological clearance in two cases of clinical T4b dMMR/MSI-h advanced colorectal cancer: the potential of immune checkpoint inhibitors despite positive positron-emission tomography results.

The standard treatment for colorectal cancer consists of surgery and chemotherapy, which can be combined to improve outcomes. Immune checkpoint inhibitors (ICI) are a significant advancement in the standard treatment of metastatic, unresectable colorectal cancer with deficient mismatch repair (dMMR). However, limited data are available about the use of ICI in the neoadjuvant and conversion settings. Here, we present two cases treated with ICI. Case 1: A 75-year-old male with a large, borderline resectable rectal cancer diagnosed as cT4bN1bM0 who underwent neoadjuvant chemotherapy, followed by combination ICI consisting of ipilimumab and nivolumab. After four courses of ICI, the tumor significantly shrank, but positron emission tomography still showed a positive result and R0 resection was performed. Pathological analysis revealed no residual cancer cells. The patient has been monitored without adjuvant chemotherapy, and no recurrences have occurred after one year. Case 2: A 60-year-old male with locally advanced sigmoid colon cancer who received neoadjuvant treatment with pembrolizumab. The tumor partially shrank after three courses, and continued pembrolizumab monotherapy resulted in further tumor shrinkage which still showed positive positron emission tomography. Curative sigmoidectomy with partial resection of the ileum and bladder was performed, and the pathological outcome was pCR. There was no viable tumor in the specimen. The patient has been monitored without adjuvant chemotherapy for six months, and no recurrence has been observed. The present study reports two cases, including a large, borderline resectable rectal cancer after failure of chemotherapy followed by combination treatment with nivolumab and ipilimumab and one case of sigmoid colon cancer after pembrolizumab treatment, which resulted in pathological complete response. However, it remains unknown whether ICI therapy can replace surgery or diminish the optimal extent of resection, or whether adjuvant chemotherapy is needed after surgery in the case of achieving pCR after ICI therapy. Overall, this case report suggests that ICI before colorectal surgery can be effective and potentially a 'watch-and-wait" strategy could be used for cases in which ICI is effective.

VIC Regimen (Vemurafenib/Irinotecan/Cetuximab) Versus Bevacizumab Plus Chemotherapy as First-Line Treatment for BRAF V600E-Mutated Unresectable or Metastatic Colorectal Cancer in Asian Patients: A Prospective Cohort Study

BackgroundColorectal cancers (CRC) with BRAF V600E mutation exhibit limited chemotherapy response and a poor prognosis. Safety and efficacy of the VIC (Vemurafenib/Irinotecan/Cetuximab) regimen in the first-line setting for patients with BRAF V600E-mutated CRC remain undetermined. MethodsIn the prospective cohort study, the untreated, BRAF V600E-mutated, unresectable or metastatic CRC patients were enrolled. The VIC regimen and bevacizumab plus chemotherapy were compared in the first-line setting. The objective response rate (ORR), disease control rate (DCR), conversion resection rate, progression-free survival (PFS), and overall survival (OS) were evaluated. ResultsIn the intent-to-treat analysis, 38 patients received VIC regimen and 40 received bevacizumab plus chemotherapy. The ORR and DCR in the VIC group were significantly higher than in the bevacizumab-therapy group (ORR: 63.2% vs. 37.5%, P = .025; DCR: 94.7% vs. 75.0%, P = .019). The VIC regimen significantly outperformed bevacizumab plus chemotherapy in both PFS (11.9 vs. 7.7 months; hazard ratio [HR] = 0.51, 95% CI, 0.30-0.87; P = .010) and OS (25.3 vs. 14.6 months; HR = 0.43, 95% CI, 0.22-0.82; P = .011). In the VIC group, the conversion resection rate for liver metastases was 34.8% (8 of 23 patients), and for unresectable local CRC it was 54.5% (6 of 11 patients). The adverse events rates of Grade 3 to 4 were 34.2% and 32.5% for the VIC regimen and bevacizumab plus chemotherapy respectively. ConclusionsAmong Asian patients with BRAF V600E-mutated CRC, the VIC regimen showed favorable outcomes compared to bevacizumab plus chemotherapy in terms of tumor response and oncological survival, with a tolerable and manageable toxicity profile in the first-line setting.

Estimating Efficacy of Conversion Therapy on Patients with Initially Unresectable Colorectal Cancer Liver Metastases by using MRI: Development of a Predictive Score

The conversion success rate (CSR) has crucial implication for clinical outcomes of initially unresectable colorectal liver metastases (CRLM) following conversion therapy. This study aimed to develop a simple predictive scoring model for identifying CSR according to baseline magnetic resonance imaging (MRI) features, and confirm its performance and prognostic significance in a validation cohort. A total of 155 consecutive patients with initially unresectable CRLM were retrospectively reviewed in the study. A simple MRI-based predictive scoring model for identifying CSR was developed in the development cohort (n=104) by using multivariable logistic regression analyzes. The diagnostic performance was evaluated for the predictive score. Thereafter, patients in the validation cohort (n=51) were stratified into groups with predicted high CSR or low CSR according to the score. The progression-free survival (PFS) and overall survival (OS) were compared between two groups using the log-rank test. The predictive score of CSR, named mrNISE, incorporated the number of CRLM ≥10, the largest size ≥50mm, poorly defined tumor-liver interface, and peritumoral enhancement. The AUC of the mrNISE score was 0.845 for the development cohort and 0.776 for the validation cohort. According to the score, patients with predicted high CSR had better PFS and OS than those with low CSR in both development and validation cohorts. The predictive score demonstrated great performance for identifying CSR of initially unresectable CRLM. Stratifying patients by the score, personalized treatment goals can be formulated before conversion therapy to improve clinical prognosis and reduce adverse events caused by ineffective treatment.

Abstract CT276: Liberty-201: Maintenance fluoropyrimidine (FP) and bevacizumab with or without anti-lymphocyte activation gene-3 (LAG-3) antibody LBL-007 plus anti-programmed cell death protein-1 (PD-1) antibody tislelizumab (TIS) for patients (pts) with metastatic or unresectable microsatellite stable (MSS)/mismatch repair proficient (pMMR) colorectal cancer (CRC)

Abstract Background: LBL-007 is a monoclonal antibody targeting LAG-3, a receptor expressed on immune cells that negatively regulates T-cell proliferation and effector T-cell function. LAG-3 is frequently co-expressed with PD-1 on tumor-infiltrating T cells, and dual inhibition of LAG-3/PD-1 synergistically prevents tumor growth in mouse models. CRC is the second-highest cancer-related cause of death worldwide; pts diagnosed with metastatic CRC have a 5-year survival rate of 14%. Immunotherapy (IO) has only demonstrated clinical benefit in pts with microsatellite instability-high/MMR-deficient CRC, which accounts for 5% of CRC pts; however, improved therapy options for patients with MSS CRC remain limited. The combination of anti-LAG-3 + anti-PD-1 IO is currently being tested in clinical trials in pts with MSS CRC. Methods: This is a phase 1b/2, randomized, open-label study (NCT05609370). Pts with unresectable or metastatic CRC with locally or centrally confirmed pMMR or MSS status and no disease progression after induction treatment in first-line therapy are eligible. A maximum of 36 pts will be enrolled in phase 1b (safety run-in) to determine the recommended phase 2 dose. All pts will receive intravenous dual IO (LBL-007 + TIS) in combination with maintenance backbone (FP + bevacizumab). The dose of LBL-007 will be escalated from 150 mg every 3 weeks (Q3W) to 600 mg Q3W/400 mg Q2W using a Bayesian optimal interval design with informative prior. In phase 2, ~130 pts will be enrolled in the programmed death-ligand 1 (PD-L1)-positive group (tumor area positivity [TAP] ≥1%) and 60 patients in the PD-L1-negative group (TAP &amp;lt;1%). Pts with a PD-L1-positive status will be randomized 2:1:2 to receive dual IO + maintenance backbone (Arm A), LBL-007 + maintenance backbone (Arm B), or maintenance backbone only (Arm C). Pts with a PD-L1-negative status will be randomized 1:1 to receive dual IO + maintenance backbone (Arm D) or maintenance backbone only (Arm E). Treatment will continue until disease progression or unacceptable toxicity. The primary endpoint is safety in phase 1b and investigator-assessed progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 in phase 2. Secondary endpoints include overall survival, PFS2, overall response rate, duration of response, safety, pharmacokinetics, and immunogenicity. Exploratory endpoints include potential biomarkers (including but not limited to PD-L1 and LAG-3). Citation Format: Heinz-Josef Lenz, Ying Yuan, Vivian Li, Juan Zhang, Lubna Jamal, Xiao Lin, Fuxiang Zhu, John H. Strickler. Liberty-201: Maintenance fluoropyrimidine (FP) and bevacizumab with or without anti-lymphocyte activation gene-3 (LAG-3) antibody LBL-007 plus anti-programmed cell death protein-1 (PD-1) antibody tislelizumab (TIS) for patients (pts) with metastatic or unresectable microsatellite stable (MSS)/mismatch repair proficient (pMMR) colorectal cancer (CRC) [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 CT276.

Prognostic factors for overall survival and safety of trans-arterial chemoembolization (TACE) with irinotecan-loaded drug-eluting beads (DEBIRI) in patients with colorectal liver metastases.

Transarterial chemoembolisation with irinotecan-loaded drug-eluting beads (DEBIRI TACE) can be considered in patients with unresectable colorectal cancer liver metastases (CRLM) who progress after all approved standard therapies or in patients unsuitable for systemic therapy. Between September 2010 and March 2020, thirty patients (22 men and 8 women; mean age 66.8 ± 13.2) were included in this retrospective study. DEBIRI TACE was conducted in 43% of patients unsuitable for systemic therapy as a first-line treatment and 57% as salvage therapy after the progression of systemic therapy. All the patients had liver-limited disease. In the case of unilobar disease, two treatments were performed at four-week intervals, and in the case of bilobar disease, four treatments were performed at two-week intervals. All patients were premedicated and monitored after the procedure. Adverse events were graded according to the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system for complications. The median overall survival (OS) from the beginning of DEBIRI TACE in the salvage group was 17.4 months; in the group without prior systemic therapy, it was 21.6 months. The median overall survival of all patients was 17.4 months (95% confidence interval [CI]: 10.0-24.7 months), and progression-free survival (PFS) was 4.2 months (95% CI: 0.9-7.4 months). The one-year survival rate after the procedure was 61%, and the two-year rate was 25%. Univariate analysis showed better survival of patients with four or fewer liver metastases (p = 0.002). There were no treatment-related deaths or grade 4 and 5 adverse events. Nonserious adverse events (Grades 1 and 2) were present in 53% of patients, and Grade 3 adverse events were present in 6% of the patients. DEBIRI TACE is a well-tolerated treatment option for patients with liver metastases of colorectal cancer. Patients with four or fewer liver metastases correlated with better survival.

Clinical Impact of Nutrition and Inflammation Assessment Tools in Colorectal Cancer Treatment.

For resectable colorectal cancer (CRC), the standard treatment is perioperative adjuvant treatment and complete resection. For unresectable CRC, the standard treatment is systemic chemotherapy. The detection of promising biomarkers is necessary for optimizing the management of CRC and improving patient survival. If physicians can detect useful biomarkers, patients with CRC may benefit from more aggressive or less toxic treatment. Recent studies have shown that the inflammatory and nutritional status both influence the short and long-term oncological outcomes of patients with CRC during perioperative and/or chemotherapy. The utility of several tools for the evaluation of the inflammation and nutritional status has been reported. The introduction of such tools in the management of CRC could have a beneficial impact on postoperative surgical complications or adverse events of chemotherapy. An understanding of the characteristics of each of these evaluations is necessary for their introduction in daily clinical practice. The present report summarizes the background and current status of nutrition and inflammation evaluation tools and future perspectives on their application in the management of patients with CRC.

Abstract 6101: PLASMUT: An R Package for estimating the probability of tumor-specific mutations in cell-free DNA

Abstract Noninvasive approaches for detection of tumor-specific mutations in cell-free DNA (cfDNA) have the potential to track a patient’s response to treatment, enabling effective and timely decisions on therapy. However, mutations in cfDNA arising from clonal hematopoeisis (CH) are common and tumor biopsies for definitive identification of the origin of these mutations are not always available. Sequencing of matched cells from buffy coat and the absence of mutations in these cells has been used to rule-out white blood cell (WBC) mutations, but uneven sequencing depths between matched cfDNA and buffy coat and the fraction of mutant alleles are generally ignored by rule-based tests. A probabilistic approach that quantifies the evidence of tumor-derived mutations in cfDNA is needed. We developed a Bayesian framework to estimate the probability that a mutation identified in cfDNA is tumor specific. Our approach requires the number of reads with a mutant allele in plasma (yp) and WBCs (yw) and the corresponding number of total distinct reads at these locations. The posterior odds that a mutation is tumor-derived (S) versus CH or germline (H) is given by the ratio of the probabilities of observing the distinct reads given each model times the prior odds. Estimation of the Bayes factor is obtained by integrating over the unobserved mutant allele fractions in plasma and WBCs using Monte Carlo importance sampling. We applied this approach to 52 patients with initially unresectable colorectal cancer (CRC) liver metastases in the CAIRO5 clinical trial (NCT02162563), using ultra-deep targeted sequencing of cfDNA from plasma and matched WBCs. Among the CAIRO5 patients analyzed, we identified 95 mutations with moderate evidence of tumor-derived cfDNA mutations (Bayes factor &amp;gt; 10) and 19 mutations that were CH-derived (Bayes factor &amp;lt; 0.1). For a subset of 47 cfDNA mutations with no corresponding mutation identified by WBC sequencing, the evidence of tumor origin was highly variable (Bayes factor range: 0.03 to 5.6). While the standard rule-based approach identifies all of these mutations as tumor-derived, none of these mutations reach a moderate evidence cutpoint (all Bayes factors &amp;lt; 6). As a false positive would lead to identification of cfDNA mutations that do not track tumor burden, requiring even higher levels of evidence (Bayes factor &amp;gt; 99) for the selection of cfDNA mutations could be warranted, and still identifies one or more cfDNA mutations in 43 of the patients. This approach is implemented in the R package PLASMUT available from Bioconductor (doi:10.18129/B9.bioc.plasmut). We developed an approach that quantifies the evidence between two competing models for the origin of mutations in cfDNA. A cutpoint for determination of the probability of tumor-derived cfDNA mutations can be tailored to the disease application, balancing the potential benefits of noninvasive testing with the harms of false positives and negatives. Citation Format: Adith S. Arun, Jamie E. Medina, Stephen Cristiano, Daniel C. Bruhm, Remond J. Fijneman, Gerrit A. Meijer, Alessandro Leal, Victor E. Velculescu, Robert B. Scharpf. PLASMUT: An R Package for estimating the probability of tumor-specific mutations in cell-free DNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6101.