We propose a working hypothesis that integrates data from the CALGB/SWOG 80405 and FIRE-3 studies to explain apparent discrepancies in their results. Both trials assessed the combination of either ...cetuximab or bevacizumab with a different chemotherapy backbone: irinotecan in all patients in the FIRE-3 study, or oxaliplatin in 75% of the patients in the CALGB/SWOG 80405 study. The hypothesis is divided into three parts. Firstly, in addition to the biology or microenvironment of the tumour and the selection of the biologically targeted agents common to both trials, chemotherapy itself is an important variable that determines treatment efficacy because of a complex interplay between the biological therapy, the chemotherapy, and the microenvironment. Secondly, the tumour microenvironment, as defined by the Consensus Molecular Subtypes (CMS) classification, determines the interaction of chemotherapeutic agents with biologically targeted agents such as bevacizumab and cetuximab. Whereas irinotecan synergises with cetuximab across all CMS subtypes, oxaliplatin might have variable effects, synergising with cetuximab in fibroblast-poor microenvironments, such as CMS2 and CMS3, but activating fibroblast-rich microenvironments, such as CMS1 and CMS4, to release cytokines that might antagonise some of the cetuximab effects. Thirdly, the previous assumptions integrate into a final concept, which is that overall survival is determined not only by the biological therapy or the first-line treatment, but specifically by the sequence of first-line and second-line regimens, and the degree of synergism between them. In a clinical setting, the optimal first-line combination of biological therapy and chemotherapy predetermines the crossover to a specific second-line treatment, which affects the overall survival of a patient with a specific tumour subtype. Our working hypothesis suggests that the CALGB/SWOG 80405 and FIRE-3 studies are complementary rather than discrepant, and it provides an explanation for their opposing interpretations. In conclusion, proper interpretation of the CALGB/SWOG 80405 and FIRE-3 results requires an in-depth examination of the complex interplay, not only between the targeted biological agents and chemotherapeutic drugs, but also between therapies and the tumour biology and microenvironment, for each line of treatment.
Highlights • TAS-102 is an oral fluorothymidine agent for the treatment of cancer. • TAS-102 is a combination of the thymidine analog trifluridine (FTD) and tipiracil. • Tipiracil, a thymidine ...phosphorylase inhibitor, improves FTD bioavailability. • Compared with 5-fluorouracil (5-FU), TAS-102 has a distinct mechanism of action and metabolism. • TAS-102 has demonstrated efficacy in 5-FU-refractory cancers.
The achievements in the treatment of metastatic colorectal cancer during recent years are based on a better understanding of the disease and individualized regimen planning. In adjuvant treatment, ...the highly important IDEA (International Duration Evaluation of Adjuvant Chemotherapy) study has shown that treatment duration can safely be reduced in selected patient populations. In patients with pN1 and pT1-pT3 tumors, 3 months of treatment with 5-fluorouracil and oxaliplatin is comparable with respect to 3-year survival rate to 6 months of treatment. For patients with N2 tumors, 6 months of treatment should stay the standard of care. The limitation of the duration of the adjuvant treatment is significantly reducing the chemotherapy-induced morbidity. New studies will explore the use of immune-checkpoint inhibitors in the adjuvant setting in microsatellite-instable (MSI) tumors. In metastatic disease, next to the required molecular testing for
and
mutations, MSI testing is recommended. In the rare group of patients with a MSI tumor, immune-checkpoint inhibition is changing the course of the disease dramatically. Therefore, it is important to identify those patients early. For the
-mutant cases, no new and targeted treatment options have been identified yet. An optimal treatment strategy for those patients is urgently needed.
wild-type patients with tumors derived from the left side of the colon (splenic flexure to rectum) should be treated in first line with epithelial growth factor receptor (EGFR) antibodies. This selection by a molecular and a clinical marker increased the benefit derived by EGFR antibodies dramatically and defined the most effective treatment option for those patients. New selection criteria based on gene expression, methylation, and other molecular changes are explored and will further influence our therapeutic strategies in the future.
•5-FU and leucovorin are standard therapy in metastatic colorectal cancer.•Systemic chemotherapy agents can increase the efficacy of 5-FU-based treatments.•Optimising route of administration, dosage ...and folate metabolism improves efficacy.•Recent research has focused on addressing variability in folate metabolism.•Agents that do not require metabolic conversion are promising candidate therapies.
Notwithstanding recent treatment advances in metastatic colorectal cancer (mCRC), chemotherapy with a combination of a fluoropyrimidine and a folate agent, often 5-fluorouracil (5-FU) and leucovorin, remains the backbone of treatment regimens for the majority of patients with mCRC. This is despite a recent focus on molecular-targeted treatments and patient stratification according to mutational status or expression levels of specific genes. Intracellular folate concentration was discovered to be pivotal in the cytotoxic efficacy of 5-FU, paving the way to the current standard combination therapy approach. Subsequent discovery that systemic chemotherapy agents, such as irinotecan and oxaliplatin, can further increase the efficacy of 5-FU-based treatments led to the development of several combination chemotherapy regimens, including FOLFOX, FOLFIRI and FOLFOXIRI. Subsequent efforts to optimise 5-FU-based treatments have focused on 5-FU analogues, initially capecitabine and the combination drug tegafur/gimeracil/oteracil (S-1) and then TAS-102, which has recently been evaluated in phase 3 clinical trials for refractory colorectal cancer. Further approaches taken to improve the efficacy of 5-FU chemotherapy regimens have focused on optimising the route and dosing schedules and regulating folate metabolism. Pharmacokinetic variability caused by the requirement for metabolic conversion of leucovorin has been central to recent research, and the development of agents such as arfolitixorin which bypass the need for metabolic conversion remains promising for future therapeutic candidates. In this review, we summarise the evidence leading to the current treatment regimens employing 5-FU and leucovorin, focusing on recent approaches taken to optimise and refine treatments to improve clinical outcomes in patients with mCRC.
Cetuximab and panitumumab are two distinct monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR), and both are widely used in combination with chemotherapy or as ...monotherapy to treat patients with
RAS
wild-type metastatic colorectal cancer. Although often considered interchangeable, the two antibodies have different molecular structures and can behave differently in clinically relevant ways. More specifically, as an immunoglobulin (Ig) G1 isotype mAb, cetuximab can elicit immune functions such as antibody-dependent cell-mediated cytotoxicity involving natural killer cells, T-cell recruitment to the tumor, and T-cell priming via dendritic cell maturation. Panitumumab, an IgG2 isotype mAb, does not possess these immune functions. Furthermore, the two antibodies have different binding sites on the EGFR, as evidenced by mutations on the extracellular domain that can confer resistance to one of the two therapeutics or to both. We consider a comparison of the properties of these two antibodies to represent a gap in the literature. We therefore compiled a detailed, evidence-based educational review of the known molecular, clinical, and functional differences between the two antibodies and concluded that they are distinct therapeutic agents that should be considered individually during treatment planning. Available data for one agent can only partly be extrapolated to the other. Looking to the future, the known immune activity of cetuximab may provide a rationale for this antibody as a combination partner with investigational chemotherapy plus immunotherapy regimens for colorectal cancer.
Summary Background FIRE-3 compared first-line 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) plus cetuximab with FOLFIRI plus bevacizumab in patients with KRAS exon 2 wild-type metastatic ...colorectal cancer. The same study also reported an exploratory analysis of a subgroup of patients with tumours that were wild-type at other RAS genes ( KRAS and NRAS exons 2–4). We report here efficacy results for the FIRE-3 final RAS ( KRAS/NRAS , exons 2–4) wild-type subgroup. Moreover, new metrics of tumour dynamics were explored during a centralised radiological review to investigate how FOLFIRI plus cetuximab conferred overall survival benefit in the absence of differences in investigator-assessed objective responses and progression-free survival. Methods FIRE-3 was a randomised phase 3 trial comparing FOLFIRI plus cetuximab with FOLFIRI plus bevacizumab in the first-line treatment of patients with KRAS exon 2 wild-type metastatic colorectal cancer. The primary endpoint of the FIRE-3 study was the proportion of patients achieving an objective response according to Response Evaluation Criteria In Solid Tumors (RECIST) 1.0 in the intention-to-treat population. A centralised radiological review of CT scans was done in a post-hoc analysis to assess objective response according to RECIST 1.1, early tumour shrinkage, depth of response, duration of response, and time to response in the final RAS wild-type subgroup. Comparisons between treatment groups with respect to objective response rate and early tumour shrinkage were made using Fisher's exact test (two-sided), while differences in depth of response were investigated with a two-sided Wilcoxon test. This trial is registered at ClinicalTrials.gov , number NCT00433927. Findings In the final RAS wild-type population (n=400), median overall survival was better in the FOLFIRI plus cetuximab group than the FOLFIRI plus bevacizumab group (33·1 months 95% CI 24·5–39·4 vs 25·0 months 23·0–28·1; hazard ratio 0·70 0·54–0·90; p=0·0059), although investigator-assessed objective response and progression-free survival were comparable between treatment groups. Centralised radiological review of CT-assessable patients (n=330) showed that the proportion of patients achieving an objective response (113 of 157, 72·0% 95% CI 64·3–78·8 vs 97 of 173, 56·1% 48·3–63·6; p=0·0029), frequency of early tumour shrinkage (107 of 157, 68·2% 60·3–75·4 vs 85 of 173, 49·1% 41·5–56·8; p=0·0005), and median depth of response (–48·9% –54·3 to −42·0 vs −32·3% –38·2 to −29·2; p<0·0001) were significantly better in extended RAS wild-type patients receiving FOLFIRI plus cetuximab versus those receiving FOLFIRI plus bevacizumab. No differences in duration of response and time to response were observed between treatment groups. Interpretation This analysis provides a new framework that connects alternative metrics of response to overall survival. Superior response-related outcome parameters, such as early tumour shrinkage and depth of response, obtained by centralised radiological review correlated with the overall survival benefit conferred by FOLFIRI plus cetuximab compared with FOLFIRI plus bevacizumab in the extended RAS wild-type subgroup. Funding Merck KGaA and Pfizer.
Cetuximab plus FOLFIRI improved overall survival compared with bevacizumab plus FOLFIRI in KRAS wild-type metastatic colorectal cancer (mCRC) in FIRE-3, but no corresponding benefit was found for ...progression-free survival. This analysis aimed to determine whether cetuximab improves response and survival versus bevacizumab among response-evaluable patients receiving first-line FOLFIRI for RAS wild-type mCRC and the effect of primary tumour side on outcomes.
The intent-to-treat population included 593 patients with KRAS exon 2 wild-type mCRC. Further testing identified 400 patients with extended RAS wild-type disease; of these, 352 (88%) who received ≥3 cycles of therapy and had ≥1 post-baseline scan were evaluable for response and constituted the per-protocol population (169 cetuximab and 183 bevacizumab). Patients received 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) with either weekly cetuximab or biweekly bevacizumab given on day 1 of each 14-day cycle until response, progression or toxicity occurred. The primary endpoint was the objective response rate (ORR) in the per-protocol population. Secondary endpoints included overall survival (OS) and progression-free survival (PFS). The effect of primary tumour location was evaluated.
Median OS in the RAS wild-type population was 31 vs 26 months in the cetuximab and bevacizumab groups, respectively (HR 0.76, P = 0.012). In the per-protocol population, outcomes favoured cetuximab for ORR (77% vs 65%, P = 0.014) and median OS (33 vs 26 months, HR 0.75, P = 0.011), while PFS was comparable between groups. The advantage of cetuximab over bevacizumab occurred only in patients with left-sided primary tumours.
FOLFIRI plus cetuximab resulted in a significantly higher ORR and longer OS compared to FOLFIRI plus bevacizumab among patients with left-sided tumours. The superior response associated with cetuximab may particularly benefit patients with symptomatic tumours or borderline-resectable metastases. CLINICALTRIALS.
NCT00433927.
The percentage of the planned dose received, however, was superior in the dose-escalation group in cycle 2 (median 100·0% IQR 95·2–100·0 vs 75·0% 50·0–100·0). ...with a slightly better toxicity ...profile and comparable dose exposure in cycle 2, a higher percentage of patients initiated cycle 3 in the dose-escalation group, thus making ReDOS a positive trial. ...it is—as is often the case with clinical trials including patients in the refractory treatment setting—questionable whether the study results obtained in ReDOS are transferable to most patients treated under routine clinical conditions. ReDOS took almost 25 months to achieve its recruitment goal of 116 evaluable patients in 39 centres, an average of 1·4 patients per centre per year. ...an obviously small subset of all patients was included in the ReDOS study that might not represent the majority of patients treated with regorafenib.
Ferroptosis, an iron and reactive oxygen species (ROS)-dependent non-apoptotic type of regulated cell death, is characterized by a massive iron overload and peroxidation of polyunsaturated fatty ...acids (PUFAs), which finally results in cell death. Recent studies suggest that ferroptosis can influence carcinogenesis negatively and therefore may be used as a novel anti-cancer strategy. Hepatocellular carcinoma (HCC) is a deadly malignancy with poor chances of survival and is the second leading cause of cancer deaths worldwide. Diagnosis at an already late stage and general resistance to current therapies may be responsible for the dismal outcome. As the liver acts as a key factor in iron metabolism, ferroptosis is shown to play an important role in HCC carcinogenesis and, more importantly, may hold the potential to eradicate HCC. In this review, we summarize the current knowledge we have of the role of ferroptosis in HCC and the application of ferroptosis as a therapy option and provide an overview of the potential translation of ferroptosis in the clinical practice of HCC.
COVID-19 pandemic challenges health system capacities in many countries. National healthcare services have to manage unexpected shortage of healthcare resources that have to be reallocated according ...to the principles of fair and ethical prioritisation, in order to maintain the highest levels of care to all patients, ensure the safety of patients and healthcare workers and save as many lives as possible. Beyond that, cancer care services have to pursue restructuring, following the same evidence-based dispositions. In this article, we propose guidance to the management of colorectal cancer during the pandemic, prioritised according to a three-tiered framework, based on expert clinical judgement and magnitude of benefit expected from specific interventions. Since the availability of resources for diagnostic procedures, surgery and postoperative care, systemic therapy and radiotherapy may differ, authors did separate prioritisation analyses. The impact of postponing or abrogating cancer interventions on outcomes according to a high, medium or low priority scale, is outlined and discussed. The implementation of healthcare services using telemedicine is explored: it reveals itself as functional and effective for limiting patients’ need to travel to centres and thereby has the potential to reduce diffusion of severe acute respiratory syndrome coronavirus 2. Colorectal cancer demands a considerable amount of medical resources. Therefore, the redefinition of its diagnostic and therapeutic algorithms with a rigorous method is crucial in order to ensure the highest quality of continuum of care in the broader context of the pandemic and the challenged healthcare systems.
PDF
