Considering FOLFOXIRI plus bevacizumab for metastatic colorectal cancer with left-sided tumors

A recent subgroup analysis of the TRIBE trial suggested that FOLFOXIRI plus bevacizumab may be a preferred option for the first-line treatment of only right-sided metastatic colorectal cancer (mCRC), regardless of RAS or BRAF status. Our subanalysis of a phase II trial of the FOLFOXIRI triplet regimen plus bevacizumab in patients with mCRC who had RAS mutant tumors showed that tumor shrinkage was better and the duration of treatment was longer in patients with left-sided tumors than in those with right-sided tumors, leading to a higher rate of conversion to surgery in mCRC patients with left-sided tumors. The early and deep responses to the triplet-regimen in patients with left-sided tumors might facilitate conversion treatment resulting in favorable survival. Our data suggest that the FOLFOXIRI plus bevacizumab might be a promising treatment for left-sided mCRC involving RAS mutant tumors.     

Impact of RAS and BRAF mutations on carcinoembryonic antigen production and pattern of colorectal metastases

AIM: To investigate the impact of RAS and BRAF mutations on the pattern of metastatic disease and carcinoembryonic antigen (CEA) production. METHODS: In this retrospective study, we investigated the impact of RAS and BRAF mutational status on pattern of metastatic disease and CEA production. Only patients presenting with a newly diagnosed metastatic colorectal cancer (CRC) were included. Patients’ characteristics, primary tumor location, site of metastatic disease and CEA at presentation were compared between those with and without RAS and BRAF mutations. RESULTS: Among 174 patients, mutations in KRAS, NRAS and BRAF were detected in 47%, 3% and 6% respectively. RAS mutations (KRAS and NRAS) were more likely to be found in African American patients (87% vs 13%; P value = 0.0158). RAS mutations were associated with a higher likelihood of a normal CEA (< 5 ng/mL) at presentation. BRAF mutations were more likely to occur in females. We were not able to confirm any association between mutational status and site of metastatic disease at initial diagnosis. CONCLUSION: No association was found between RAS and BRAF mutations and sites of metastatic disease at the time of initial diagnosis in our cohort. Patients with RAS mutations were more likely to present with CEA levels < 5 ng/mL. These findings may have clinical implications on surveillance strategies for RAS mutant patients with earlier stages of CRC.     

BRAF V600突变阳性的晚期黑色素瘤治疗的临床研究进展

多数黑色素瘤具有BRAF V600E/K突变,因此V600成为黑色素瘤精准治疗的重要靶点,并通常可被BRAF抑制剂和MEK抑制剂联合阻断。免疫检查点抑制剂的出现也极大地改善了BRAF V600突变阳性的晚期黑色素瘤患者的治疗结局,探究这部分患者的最佳一线治疗及序贯治疗顺序的临床试验正在开展。本文就精准医疗时代BRAF V600突变阳性的晚期黑色素瘤患者治疗的最新研究进展进行综述。     

New horizons for uncommon mutations in non-small cell lung cancer: BRAF,KRAS, RET,MET, NTRK,HER2

The 2004 discovery of EGFR mutations, followed by ALK rearrangements, ushered in a targeted therapy era for advanced non-small cell lung cancer (NSCLC). Tyrosine kinase inhibitors targeting gene alterations have substantially improved survival and quality of life for patients with NSCLC. In the last decade, rearrangements of the ROS1 oncogene have been incorporated into healthcare practice that are applicable to another small subgroup of patients who benefit from similar targeted strategies. Recent genome studies of lung adenocarcinoma have identified other possible therapeutic targets, including RET, NTRK fusions, c-MET alterations, and activating mutations in KRAS, BRAF, and HER2, all with frequencies greater than 1%. Lung cancers harbouring these genome changes can potentially be treated with agents approved for other indications or under clinical development. This review updates the therapeutic arsenal that especially targets those genes.     

Role of targeted therapy in metastatic colorectal cancer

Colorectal cancer (CRC) is a significant cause of cancer-related morbidity and mortality all over the world. Improvements of cytotoxic and biologic agents have prolonged the survival in metastatic CRC (mCRC), with a median overall survival of approximately 2 years and more in the past two decades. The biologic agents that have proven clinical benefits in mCRC mainly target vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR). In particular, bevacizumab targeting VEGF and cetuximab and panitumumab targeting EGFR have demonstrated significant survival benefits in combination with cytotoxic chemotherapy in the first-line, second-line, or salvage setting. Aflibercept, ramucirumab, and regorafenib are also used in second-line or salvage therapy. Recent retrospective analyses have shown that KRAS or NRAS mutations were negative predictive markers for anti-EGFR therapy. Based on the evidence from large randomized clinical trials, personalized therapy is necessary for patients with mCRC according to their tumor biology and characteristics. The aim of this paper was to summarize the results of the major randomized clinical trials and highlight the benefits of the molecular targeted agents in patients with mCRC.     

Liquid biopsy to detect resistance mutations against anti-epidermal growth factor receptor therapy in metastatic colorectal cancer

Colorectal cancer (CRC) is a major cause of mortality worldwide, associated with a steadily growing prevalence. Notably, the identification of KRAS, NRAS, and BRAF mutations has markedly improved targeted CRC therapy by affording treatments directed against the epidermal growth factor receptor (EGFR) and other anti-angiogenic therapies. However, the survival benefit conferred by these therapies remains variable and difficult to predict, owing to the high level of molecular heterogeneity among patients with CRC. Although classification into consensus molecular subtypes could optimize response prediction to targeted therapies, the acquisition of resistance mutations to targeted therapy is, in part, responsible for the lack of response in some patients. However, the acquisition of such mutations can induce challenges in clinical practice. The utility of liquid biopsy to detect resistance mutations against anti-EGFR therapy has recently been described. This approach may constitute a new standard in the decision algorithm for targeted CRC therapy.     

Ongoing and future directions in the management of metastatic colorectal cancer: Update on clinical trials

Metastatic colorectal cancer (mCRC) continues to show poor outcomes, with many patients exhausting effective standard-of-care therapy. To explore the current landscape of clinical trials for mCRC, we reviewed over 600 clinical trials that are currently ongoing for mCRC patients. Immunotherapeutic agents form approximately 39% (includes monoclonal antibodies, viruses, vaccines, and immunomodulators) of all agents and targeted therapy forms 45% (tyrosine kinase inhibitors, epigenetic modulators, and others) of all agents being investigated for mCRC.     

Clinical efficacy and drug resistance of anti-epidermal growth factor receptor therapy in colorectal cancer

Colorectal cancer (CRC) ranked third in cancer related death and its incidence has been increasing worldwide. In recent decades important therapeutic advances have been developed in treatment of metastatic CRC (mCRC), such as monoclonal antibodies against epidermal growth factor receptor (anti-EGFR), which provided additional clinical benefits in mCRC. However, anti-EGFR therapies have limited usage due to approximately 95% of patients with KRAS mutated mCRC do not response to anti-EGFR treatment. Thus, KRAS mutation is predictive of nonresponse to anti-EGFR therapies but it alone is not a sufficient basis to decide who should not be received such therapies because; approximately fifty percent (40%-60%) of CRC patients with wild-type KRAS mutation also have poor response to anti-EGFR based treatment. This fact leads us to suspect that there must be other molecular determinants of response to anti-EGFR therapies which have not been identified yet. Current article summarizes the clinical efficacy of anti-EGFR therapies and also evaluates its resistance mechanisms.     

Recent Advances in the Clinical Development of Immune Checkpoint Blockade Therapy for Mismatch Repair Proficient (pMMR)/non-MSI-H Metastatic Colorectal Cancer

Metastatic colorectal cancer (mCRC) continues to be associated with a poor prognosis, and there remains a significant unmet need for novel agents and treatment regimens. Major breakthroughs have been made with immune checkpoint blockade therapy in several disease types, including DNA mismatch repair deficient/microsatellite instability-high (MSI-H) tumors. To date, however, immune checkpoint monotherapy has not shown significant clinical activity in the treatment of patients with mismatch repair proficient (pMMR)/non-MSI-H mCRC. The immune resistance mechanisms in pMMR/non-MSI-H mCRC have not yet been clearly elucidated. Significant efforts are currently focused on identifying effective combination immunotherapy regimens for the treatment of patients with pMMR/non-MSI-H mCRC. The combination of atezolizumab with cobimetinib had shown promising clinical activity in an early-phase clinical trial. Unfortunately, the IMblaze 370 (COTEZO) phase III trial of atezolizumab/cobimetinib combination in patients with mCRC failed to show significant improvement in overall survival in patients treated with the atezolizumab/combimetinib combination in comparison with regorafenib alone. This review summarizes the recent major advances in the clinical development of immunotherapy regimens for patients with pMMR/non-MSI-H mCRC.     

Review of the current targeted therapies for non-small-cell lung cancer

The last decade has witnessed the development of oncogene-directed targeted therapies that have significantly changed the treatment of non-small-cell lung cancer (NSCLC). In this paper we review the data demonstrating efficacy of gefitinib, erlotinib, and afatinib, which target the epidermal growth factor receptor (EGFR), and crizotinib which targets anaplastic lymphoma kinase (ALK). We discuss the challenge of acquired resistance to these small-molecular tyrosine kinase inhibitors and review promising agents which may overcome resistance, including the EGFR T790M-targeted agents CO-1686 and AZD9291, and the ALK-targeted agents ceritinib (LDK378), AP26113, alectinib (CH/RO5424802), and others. Emerging therapies directed against other driver oncogenes in NSCLC including ROS1, HER2, and BRAF are covered as well. The identification of specific molecular targets in a significant fraction of NSCLC has led to the personalized deployment of many effective targeted therapies, with more to come.     

Efficacy of cetuximab after treatment with oral epidermal growth factor receptor tyrosine kinase inhibitor-based chemotherapy in metastatic colorectal cancer

Purpose: We studied the efficacy of cetuximab therapy in patients with metastatic colorectal cancer (mCRC) previously treated with an oral inhibitor of the tyrosine kinase domain of the epidermal growth factor receptor. Patients and Methods: We reviewed the posttrial records of 73 patients with mCRC who participated in 1 of 3 clinical trials that examined a combination of gefitinib or erlotinib with standard cytotoxic chemotherapy. Medical and pharmacy records were used to identify patients who were subsequently treated with cetuximab-based therapy. Computed tomography scans during cetuximab-based therapy were reviewed, and the clinical activity of cetuximab was assessed by response rate using Response Evaluation Criteria in Solid Tumors and progression-free survival. Results: Twenty-four patients with mCRC previously treated with gefitinib or erlotinib and combination cytotoxic chemotherapy who subsequently received cetuximab-based therapy were identified. While receiving cetuximab-based therapy, no patient experienced a partial or complete response; however, 3 patients (16% of patients with available scans for formal measurements) had a minor response, defined as a 15%-29.9% decrease in the sum of longest dimensions of target lesions, and 72% had stable disease. The progression-free survival was 5.1 months for all patients and 6 months for patients who had documented progression of disease while previously receiving gefitinib- or erlotinib-based therapy. Conclusion: Cetuximab appears to have clinical benefit in patients with mCRC previously treated with a chemotherapy regimen that included an oral tyrosine kinase inhibitor of epidermal growth factor receptor. Whether these results apply to other cancer types is unknown but worthy of further study.     

局部晚期或转移性儿童及青少年分化型甲状腺癌的基因特征与临床特征及131I疗效的关系

背景与目的： 儿童及青少年分化型甲状腺癌（differentiated thyroid cancer,DTC）的分子生物学特征及其临床指导意义尚不明确。本研究拟初步探讨局部晚期或转移性DTC患儿的基因特征分布及其与临床特征及¹³¹I疗效的关系。方法： 采用甲状腺癌相关基因panel（ThyroLead^®）对2020年12月—2021年7月就诊于中国医学科学院北京协和医学院北京协和医院的儿童及青少年侵袭性DTC的原发灶进行测序,并回顾性收集患儿的临床病理学特征及¹³¹I治疗相关资料,分析其基因特征与其临床病理学特征及¹³¹I疗效的关系。结果： 本队列纳入39例局部晚期或转移性患儿,可及数据中所有患儿均存在淋巴结转移,侧方区受累率达91.4%（32/35）,远处转移率达61.5%（24/39）。61.5%（24/39）的患儿检出甲状腺癌相关基因变异,其中以RET融合（38.5%,15/39）和BRAF V600E点突变（12.8%,5/39）最为常见。突变组与非突变组的临床特征差异无统计学意义（P>0.05）。远处转移中,91.7%（22/24）的患儿在¹³¹I治疗后仍呈结构性疗效不佳（structural incomplete response,SIR）状态,其中9例患儿呈放射性碘难治（radioactive iodine-refractory,RAIR）状态。RAIR状态患儿中88.9%（8/9）检出相关基因变异,其中NCOA4/RET融合占62.5%（5/8）。进一步将RET变异组患儿细化分组显示,与其他形式的RET融合相比,NCOA4/RET融合阳性者远处转移率更高（33.3% vs 88.9%,P=0.089）,提示其具有更高的远处侵犯倾向。结论： 局部晚期或转移性DTC患儿的基因突变以融合突变尤其是RET融合为主,其中NCOA4/RET融合阳性者似乎显示出更强的侵袭性,更易呈RAIR状态。     

A retrospective on the inhibition of epidermal growth factor receptor as a therapeutic strategy for patients with relapsed metastatic colorectal cancer: impact on treatment of today's patients

The epidermal growth factor receptor (EGFR) pathway is overexpressed in many colorectal cancers (CRCs) and is associated with a worse prognosis compared with tumors that do not express EGFR. The development of monoclonal antibodies against this receptor, including cetuximab and panitumumab, and small-molecule inhibitors against the tyrosine kinase protein has led to new therapeutic paradigms in the treatment of metastatic CRC (mCRC). The anti-EGFR monoclonal antibody cetuximab has been shown to reverse chemotherapy resistance in patients with irinotecan-refractory mCRC, to improve survival compared with best supportive care (BSC) alone, and to prolong progression free-survival (PFS) in the first- and second-line settings. Panitumumab prolongs PFS compared with BSC, and trials in the first- and second-line settings are ongoing. Clinical trials with tyrosine kinase inhibitors have yielded disappointing results. This article reviews the clinical trial evidence for treatment strategies based on EGFR inhibition in relapsed/refractory mCRC, mechanisms of resistance to EGFR agents, clinical uncertainties, and future directions.     

MSS型结直肠癌免疫联合治疗研究进展

近年来,免疫治疗在恶性肿瘤治疗方面取得了很大的进展,已经丰富了多种恶性肿瘤的治疗模式。结直肠癌是全球三大常见的恶性肿瘤之一,免疫检查点抑制剂治疗对DNA错配修复缺陷（dMMR）/高微卫星不稳定性（MSI-H）转移性结直肠癌（mCRC）患者有显著临床获益,但约95%mCRC患者是错配修复完整（pMMR）/微卫星稳定（MSS）型,这类患者对单药免疫治疗的反应差,如何提高该类患者的免疫治疗疗效一直备受关注。本文就MSS型mCRC的免疫联合治疗研究进展进行综述。     

Upgraded role of autophagy in colorectal carcinomas

Autophagy is a basic catabolic process closely associated with degradation of cellular components. The role of autophagy in colorectal cancer (CRC) remains controversial. The mechanism of autophagy has been identified as protecting mechanism against tumorigenesis by isolation of damaged organelles or as cytoprotective provides energy in hypoxic regions of CRC tumors. Mutations in proto-oncogenes, such as RAS and BRAF, have been associated with autophagy initiation through signaling pathways of BRAF/MEK/ERK and PI3K/AKT/mTOR. A combination therapy of chemotherapeutic agents and autophagy inhibitors such as hydroxychloroquine or immunotherapy might represent a major step that could be evaluated as a putative novel therapeutic strategy in CRC patients.     

The changing face of treatment for metastatic colorectal cancer

Introduction: Since late 1990’s therapy of metastatic colorectal cancer (mCRC) patients has changed considerable, and the combination of doublet or triplet chemotherapy and a targeted agent are now routinely used. With the introduction of more intensified regimens, it has become even more important to identify patients that will benefit from and can tolerate therapy. Furthermore, the increasing understanding of the biology of mCRC has led to the discovery of new potential targets. Therefore, therapy of patients with mCRC has undergone considerable change from ‘one strategy fits all’ towards a more personalized therapy.

Areas covered: We present an overview of the recent literature on approved systemic treatment of mCRC however with focus on how the treatment strategy has changed based on clinical and molecular parameters that presently are used routinely in the clinical situation.

Expert commentary: The face of treatment of mCRC has changed from ‘one strategy fits all’ to a personalized approach in which both clinical, molecular parameters and the aim of therapy have to be taking into account when planning the optimal treatment strategy for the individual mCRC patient.     

The cytotoxic effects of regorafenib in combination with protein kinase D inhibition in human colorectal cancer cells

Metastatic colorectal cancer (mCRC) remains a major public health problem, and diagnosis of metastatic disease is usually associated with poor prognosis. The multi-kinase inhibitor regorafenib was approved in 2013 in the U.S. for the treatment of mCRC patients who progressed after standard therapies. However, the clinical efficacy of regorafenib is quite limited. One potential strategy to improve mCRC therapy is to combine agents that target key cellular signaling pathways, which may lead to synergistic enhancement of antitumor efficacy and overcome cellular drug resistance. Protein kinase D (PKD), a family of serine/threonine kinases, mediates key signaling pathways implicated in multiple cellular processes. Herein, we evaluated the combination of regorafenib with a PKD inhibitor in several human CRC cells. Using the Chou-Talalay model, the combination index values for this combination treatment demonstrated synergistic effects on inhibition of cell proliferation and clonal formation. This drug combination resulted in induction of apoptosis as determined by flow cytometry, increased PARP cleavage, and decreased activation of the anti-apoptotic protein HSP27. This combination also yielded enhanced inhibition of ERK, AKT, and NF-κB signaling. Taken together, PKD inhibition in combination with regorafenib appears to be a promising strategy for the treatment of mCRC.     

转移性结直肠癌维持治疗研究进展

结直肠癌是最常见的恶性肿瘤之一。近年来,奥沙利铂、5-FU类制剂、伊立替康、VEGF抗体、EGFR抑制剂等药物的使用延长了晚期结直肠癌患者的5年生存率,显著改善患者的生活质量。维持治疗是指对一线治疗后获益的患者,停用某些毒副反应较大的药物,保留低毒性药物继续治疗的一种治疗模式。因此,一些临床研究评估了上述药物在转移性结直肠癌患者一线治疗获益后的维持治疗的疗效及安全性。本文就转移性结直肠癌维持治疗方案的临床研究作一综述,全面地了解转移性结直肠癌维持治疗的相关进展。