Dynamic nature of BRAF or KRAS p.G12C mutations in second-line therapy for advanced colorectal cancer patients: do early and late effects exist?

INTRODUCTION: The mitogen-activated protein kinase (MAPK) signalling network aberrations in metastatic colorectal cancer (mCRC) generate intrinsic dynamic effects and temporal variations that are crucial but often overlooked in clinical trial populations. Here, we investigate the time-varying impact of MAPK pathway mutation genotype on each treatment line's contribution to the overall clinical course. METHODS: The PROMETEO study focused on mCRC patients undergoing second-line treatment at 20 hospitals. We evaluated genotypes and employed flexible models to analyse the dynamic effect of each mutation. RESULTS: We examined data derived from 1160 patients. The effects of KRAS G12C or G12V, and BRAF V600E are clearly time-varying, with unexpected consequences such as the deleterious effect of BRAF V600E vs other genotypes dissipating over time when subjects receive antiangiogenics, or KRAS G12V and G12C showing increasing aggressiveness over time. Thus, contrary to expectations, the 12-month survival rate from the second line for those who survived >6 months was 49.9% (95% CI, 32.7-67.3) for KRAS G12C and 59% (95% CI, 38.5-80.6) for BRAF V600E. CONCLUSIONS: The dynamic perspective is essential for understanding the behaviour of tumours with specific genotypes, especially from the second line onward. This may be relevant in patient monitoring and treatment decision-making, particularly in cases with distinct mutations.

A phase 2 study for evaluating doxycycline 50 mg once daily and 100 mg once daily as preemptive treatment for skin toxicity in patients with metastatic colorectal cancer treated with an anti-EGFR and chemotherapy.

PURPOSE: To assess the efficacy, safety, and quality-of-life outcomes of doxycycline 50 or 100 mg once daily in the prevention of skin toxicity in patients undergoing chemotherapy plus anti-EGFR therapy as first-line treatment of metastatic colorectal cancer (mCRC). METHODS: Phase II, multicenter, single-arm, exploratory study was conducted in 7 Spanish hospitals. The primary study outcome was the incidence of ≥ grade 2 skin toxicities during the 6-week skin treatment period. Quality of life was assessed with the Dermatology Life Quality Index (DLQI) questionnaire. Patients had to receive either doxycycline 50 mg once daily in a first stage with 10 patients, or, if more than three patients presented ≥ grade 2 skin toxicities, the next 30 patients had to receive 100 mg once daily. RESULTS: Thirty-four patients with RAS wild-type mCRC were enrolled in the study. Ten patients were first treated with doxycycline 50 mg once daily, and the following 24 were treated with doxycycline 100 mg once daily. A total of 60.0% (95% CI 29.6-90.0) and 20.8% (95% CI 4.6-37.0) of patients who received doxycycline 50 mg/day and 100 mg/day, respectively, had at least one ≥ grade 2 skin toxicity. Patients treated with doxycycline 100 mg once daily experienced less QoL deterioration. Only 1 patient reported a mild doxycycline-related gastrointestinal adverse event. CONCLUSION: Our results suggest that doxycycline doses as low as 100 mg once daily are efficacious and well tolerated for the prevention of skin toxicity in patients with mCRC who undergo treatment with chemotherapy plus EGFR-targeted therapies. TRIAL REGISTRATION: ClinicalTrials.gov NCT03448731.

Recommendations for the management of yttrium-90 radioembolization in the treatment of patients with colorectal cancer liver metastases: a multidisciplinary review.

PURPOSE: Strategies for the treatment of liver metastases from colon cancer (lmCRC) are constantly evolving. Radioembolization with yttrium 90 (Y-90 TARE) has made significant advancements in treating liver tumors and is now considered a potential option allowing for future resection. This study reviewed the scientific evidence and developed recommendations for using Y-90 TARE as a treatment strategy for patients with unresectable lmCRC. METHODS: A multidisciplinary scientific committee, consisting of experts in medical oncology, hepatobiliary surgery, radiology, and nuclear medicine, all with extensive experience in treating patients with ImCRC with Y-90 TARE, led this project. The committee established the criteria for conducting a comprehensive literature review on Y-90 TARE in the treatment of lmCRC. The data extraction process involved addressing initial preliminary inquiries, which were consolidated into a final set of questions. RESULTS: This review offers recommendations for treating patients with lmCRC using Y-90 TARE, addressing four areas covering ten common questions: 1) General issues (multidisciplinary tumor committee, indications for treatment, contraindications); 2) Previous process (predictive biomarkers for patient selection, preintervention tests, published evidence); 3) Procedure (standard procedure); and 4) Post-intervention follow-up (potential toxicity and its management, parameters for evaluation, quality of life). CONCLUSIONS: Based on the insights of the multidisciplinary committee, this document offers a comprehensive overview of the technical aspects involved in the management of Y-90 TARE. It synthesizes recommendations for applying Y-90 TARE across various phases of the treatment process.

Real-world study on microsatellite instability and mismatch repair deficiency testing patterns among patients with metastatic colorectal cancer in Spain.

PURPOSE: Clinical practice guidelines recommend that all patients with metastatic colorectal cancer (mCRC) should be tested for mismatch repair deficiency (dMMR) or microsatellite instability-high (MSI-H). We aimed to describe the dMMR/MSI-H testing practice in patients with mCRC in Spanish centers. METHODS: Multicenter, observational retrospective study that included patients newly diagnosed with mCRC or who progressed to a metastatic stage from early/localized stages. RESULTS: Three hundred patients were included in the study from May 2020 through May 2021, with a median age of 68 years, and two hundred twenty-five (75%) had stage IV disease at initial diagnosis; two hundred eighty-four patients received first-line treatment, and dMMR/MSI-H testing was performed in two hundred fifty-one (84%) patients. The results of the dMMR/MSI-H tests were available in 61 (24%) of 251 patients before the diagnosis of metastatic disease and in 191 (81%) of 236 evaluable patients for this outcome before the initiation of first-line treatment. Among the 244 patients who were tested for dMMR/MSI-H with IHC or PCR, 14 (6%) were MMR deficient. The most frequent type of first-line treatment was the combination of chemotherapy and biological agent, that was received by 71% and 50% of patients with MMR proficient and deficient tumors, respectively, followed by chemotherapy alone, received in over 20% of patients in each subgroup. Only 29% of dMMR/MSI-H tumors received first-line immunotherapy. CONCLUSION: Our study suggests that a high proportion of patients with mCRC are currently tested for dMMR/MSI-H in tertiary hospitals across Spain. However, there is still room for improvement until universal testing is achieved. TRIAL REGISTRATION: Not applicable.

Early Clinical Experience with Trifluridine/Tipiracil for Refractory Metastatic Colorectal Cancer: The ROS Study.

Trifluridine/tipiracil is currently approved for metastatic colorectal cancer (mCRC) refractory to available therapies. However, there is no consensus on factors that predict treatment outcomes in daily practice. We assessed the early clinical experience with trifluridine/tipiracil in Spain and potential survival markers. This was a retrospective cohort study of mCRC patients who participated in the trifluridine/tipiracil early clinical experience programme in Spain. The primary outcome was overall survival (OS). Associations between OS and patient characteristics were assessed using multivariate Cox regression analyses. A total of 379 patients were included in the study. Trifluridine/tipiracil was administered for a median of 3.0 cycles and discontinued mainly due to disease progression (79.2%). The median OS was 7.9 months, with a 12-month OS rate of 30.5%. Cox analyses revealed that the following variables independently enhanced OS: ≤2 metastatic sites, no liver metastasis, alkaline phosphatase < 300 IU, trifluridine/tipiracil dose reductions, and neutrophil/lymphocyte ratio < 5. Grade ≥ 3 toxicities were reported in 141 (37.2%) patients, including mainly afebrile neutropaenia (23.2%), anaemia (12.1%), and thrombocytopaenia (5.3%). This study supports the real-life efficacy and safety of trifluridine/tipiracil for refractory mCRC and identifies tumour burden, liver metastasis, alkaline phosphatase, dose reductions, and neutrophil/lymphocyte ratio as survival markers.

Biochemotherapy in the treatment of metastatic melanoma in selected patients.

INTRODUCTION: Bioimmunochemotherapy (BCT) is a combination of biological agents and cytostatics that has shown an increase in response rate (RR) in metastatic melanoma patients. The aim of the study is to evaluate RR, progression- free survival (PFS), overall survival (OS) and treatment toxicity. MATERIALS AND METHODS: Retrospective analysis of 11 metastatic melanoma patients treated from January 2002 to June 2008 with cisplatin 20 mg/m(2) i.v. days 1.4, dacarbazine 800 mg/m(2) i.v. day 1, vinblastine 1.5 mg/m(2) i.v. days 1.4, interleukin (IL)-2 9 MIU/m(2) s.c. 5.8 days and interferon (IFN)-alpha-2b 5 MIU/m2 s.c. days 5.9, 11, 13 and 15, with the support of granulocyte colony-stimulating factor (G-CSF) and antibiotics. Patients with ECOG 0, age < or = 65 years and with measurable disease were included. The planned number of courses was 4. RR was measured by Revised Evaluation Criteria in Solid Tumour (RECIST) criteria (computed tomography [CT]+/-proton emission tomography [PET]). Toxicity was measured according to the National Cancer Institute (NCI) common toxicity criteria. RESULTS: Observed RRs were 18% complete response (CR), 27% partial response (PR), 9% stable disease (SD) and 46% disease progression. The median PFS was 4 months (95% CI, 0.10 m), with a 23% one-year PFS. Median OS was 4.6 months (95% CI, 0.9.19 m), with a 29% one-year OS. Eighty-three percent of patients experienced grade 3-4 toxicity, mainly due to neutropenia, thrombocytopenia and flu-like syndrome. CONCLUSIONS: Treatment with BCT shows an increase in RR, some achieving durable CR; nevertheless it cannot be considered a standard treatment and should be employed only in selected patients.