A Nexus between Genetic and Non-Genetic Mechanisms Guides KRAS Inhibitor Resistance in Lung Cancer.

Several studies in the last few years have determined that, in contrast to the prevailing dogma that drug resistance is simply due to Darwinian evolution-the selection of mutant clones in response to drug treatment-non-genetic changes can also lead to drug resistance whereby tolerant, reversible phenotypes are eventually relinquished by resistant, irreversible phenotypes. Here, using KRAS as a paradigm, we illustrate how this nexus between genetic and non-genetic mechanisms enables cancer cells to evade the harmful effects of drug treatment. We discuss how the conformational dynamics of the KRAS molecule, that includes intrinsically disordered regions, is influenced by the binding of the targeted therapies contributing to conformational noise and how this noise impacts the interaction of KRAS with partner proteins to rewire the protein interaction network. Thus, in response to drug treatment, reversible drug-tolerant phenotypes emerge via non-genetic mechanisms that eventually enable the emergence of irreversible resistant clones via genetic mutations. Furthermore, we also discuss the recent data demonstrating how combination therapy can help alleviate KRAS drug resistance in lung cancer, and how new treatment strategies based on evolutionary principles may help minimize or even preclude the emergence of drug resistance.

A Closer Look at EGFR Inhibitor Resistance in Non-Small Cell Lung Cancer through the Lens of Precision Medicine.

The development of EGFR small-molecule inhibitors has provided significant benefit for the affected patient population. Unfortunately, current inhibitors are no curative therapy, and their development has been driven by on-target mutations that interfere with binding and thus inhibitory activity. Genomic studies have revealed that, in addition to these on-target mutations, there are also multiple off-target mechanisms of EGFR inhibitor resistance and novel therapeutics that can overcome these challenges are sought. Resistance to competitive 1st-generation and covalent 2nd- and 3rd-generation EGFR inhibitors is overall more complex than initially thought, and novel 4th-generation allosteric inhibitors are expected to suffer from a similar fate. Additional nongenetic mechanisms of resistance are significant and can include up to 50% of the escape pathways. These potential targets have gained recent interest and are usually not part of cancer panels that look for alterations in resistant patient specimen. We discuss the duality between genetic and nongenetic EGFR inhibitor drug resistance and summarize current team medicine approaches, wherein clinical developments, hand in hand with drug development research, drive potential opportunities for combination therapy.

Overcoming Barriers to Tobacco Cessation and Lung Cancer Screening among Racial and Ethnic Minority Groups and Underserved Patients in Academic Centers and Community Network Sites: The City of Hope Experience.

BACKGROUND: Tobacco control is important for cancer patient health, but delivering effective low-dose CT (LDCT) screening and tobacco cessation is more difficult in underserved and patients from racial and ethnic minority groups. At City of Hope (COH), we have developed strategies to overcome barriers to the delivery of LDCT and tobacco cessation. METHODS: We performed a needs assessment. New tobacco control program services were implemented focusing on patients from racial and ethnic minority groups. Innovations included Whole Person Care with motivational counseling, placing clinician and nurse champions at points of care, training module and leadership newsletters, and a patient-centric personalized medicine Personalized Pathways to Success (PPS) program. RESULTS: Emphasis on patients from racial and ethnic minority groups was implemented by training cessation personnel and lung cancer control champions. LDCT increased. Tobacco use assessment increased and abstinence was 27.2%. The PPS pilot program achieved 47% engagement in cessation, with self-reported abstinence at 3 months of 38%, with both results slightly higher in patients from racial and ethnic minority groups than in Caucasian patients. CONCLUSIONS: Tobacco cessation barrier-focused innovations can result in increased lung cancer screening and tobacco cessation reach and effectiveness, especially among patients from racial and ethnic minority groups. The PPS program is promising as a personalized medicine patient-centric approach to cessation and lung cancer screening.

Increasing clinician participation in tobacco cessation by an implementation science-based tobacco cessation champion program.

BACKGROUND: We designed a process to increase tobacco cessation in an academic center and its widely distributed network community sites using clinical champions to overcome referral barriers. METHODS: In 2020 a needs assessment was performed across the City of Hope Medical Center and its 32 community treatment sites. We reviewed information science strategies to choose elements for our expanded tobacco control plan, focusing on distributed leadership with tobacco cessation champions. We analyzed smoking patterns in patients with cancer before and following program implementation. We evaluated the champion experience and measured tobacco abstinence after 6 months of follow-up. RESULTS: Cancer center leadership committed to expanding tobacco control. Funding was obtained through a Cancer Center Cessation Initiative (C3I) grant. Multi-disciplinary leaders developed a comprehensive plan. Disease-focused clinics and community sites named cessation champions (a clinician and nurse) supported by certified tobacco treatment specialists. Patient, staff, clinician, and champion training/education were developed. Roles and responsibilities of the champions were defined. Implementation in pilot sites showed increased tobacco assessment from 80.8 to 96.6%, increased tobacco cessation referral by 367%, and moderate smoking abstinence in both academic (27.2%) and community sites (22.5%). 73% of champions had positive attitudes toward the program. CONCLUSION: An efficient process to expand smoking cessation in the City of Hope network was developed using implementation science strategies and cessation champions. This well-detailed implementation process may be helpful to other cancer centers, particularly those with a tertiary care cancer center and community network.

Pyramidal Decision Support Framework Leverages Subspecialty Expertise across Enterprise to Achieve Superior Cancer Outcomes and Personalized, Precision Care Plans.

The complexity of cancer care requires integrated and continuous support to deliver appropriate care. An expert network with complementary expertise and the capability of multidisciplinary care is an integral part of contemporary oncology care. Appropriate infrastructure is necessary to empower this network to deliver personalized precision care to their patients. Providing decision support as cancer care becomes exponentially more complex with new diagnostic and therapeutic choices remains challenging. City of Hope has developed a Pyramidal Decision Support Framework to address these challenges, which were exacerbated by the COVID pandemic, health plan restrictions, and growing geographic site diversity. Optimizing efficient and targeted decision support backed by multidisciplinary cancer expertise can improve individual patient treatment plans to achieve improved care and survival wherever patients are treated.

Addressing Drug Resistance in Cancer: A Team Medicine Approach.

Drug resistance remains one of the major impediments to treating cancer. Although many patients respond well initially, resistance to therapy typically ensues. Several confounding factors appear to contribute to this challenge. Here, we first discuss some of the challenges associated with drug resistance. We then discuss how a 'Team Medicine' approach, involving an interdisciplinary team of basic scientists working together with clinicians, has uncovered new therapeutic strategies. These strategies, referred to as intermittent or 'adaptive' therapy, which are based on eco-evolutionary principles, have met with remarkable success in potentially precluding or delaying the emergence of drug resistance in several cancers. Incorporating such treatment strategies into clinical protocols could potentially enhance the precision of delivering personalized medicine to patients. Furthermore, reaching out to patients in the network of hospitals affiliated with leading academic centers could help them benefit from such innovative treatment options. Finally, lowering the dose of the drug and its frequency (because of intermittent rather than continuous therapy) can also have a significant impact on lowering the toxicity and undesirable side effects of the drugs while lowering the financial burden carried by the patient and insurance providers.

Tragic Triad of Tobacco Dependence, Cancer, and COVID-19 Pandemic: An Urgent Call for Attention by Health Care Systems and Professionals.

Tobacco smoke is a well-known carcinogen associated with multiple malignancies. Patients with cancer, as well as survivors, who continue to smoke are at a greater risk for poor cancer treatment outcomes. With the emergence of the COVID-19 pandemic, there is increased frequency and severity of the infection in patients with cancer. Furthermore, smoking and/or vaping increases incidence or likelihood of progression of COVID-19. Cigarette smoking, cancer, and COVID-19 each impose disproportionate burden of illness and death among racial and ethnic minorities. Geographic and population-specific analyses reveal that neighborhoods with lower income and higher minority populations have more tobacco/vape shops and face increased risk associated with tobacco marketing. Referral to tobacco cessation has been reduced during the pandemic. To reduce the adverse health effects of tobacco dependence among patients with cancer during the pandemic, urgent evidence-based solutions are described for health systems and professionals to prioritize tobacco cessation for patients with cancer in the midst of the COVID-19 pandemic, on the basis of cessation implementation at City of Hope Medical Center.

Excision repair cross-complementing group-1 (ERCC1) induction kinetics and polymorphism are markers of inferior outcome in patients with colorectal cancer treated with oxaliplatin.

BACKGROUND: ERCC1, a component of nucleotide excision repair pathway, is known to repair DNA breaks induced by platinum drugs. We sought to ascertain if ERCC1 expression dynamics and a single nucleotide polymorphism (SNP) rs11615 are biomarkers of sensitivity to oxaliplatin therapy in patients with colorectal cancer (CRC). METHODS: Western blot and qPCR for ERCC1 expression was performed from PBMCs isolated from patients receiving oxaliplatin-based therapy at specified timepoints. DNA was also isolated from 59 biorepository specimens for SNP analysis. Clinical benefit was determined using progression free survival (PFS) for metastatic CRC. RESULTS: ERCC1 was induced in PBMC in response to oxaliplatin in 13/25 patients with mCRC (52%). Median PFS with ERCC1 induction was 190d compared to 237d in non-induced patients (HR 2.35, CI 1.005-5.479; p=0.0182). ERCC1 rs11615 SNP analysis revealed that 43.3% harbored C/C, 41.2%-T/C and 15.5%-T/T genotype. Median PFS was significantly lower with C/C or T/C (211 and 196d) compared to T/T (590d; p=0.0310). CONCLUSIONS: ERCC1 was induced in a sub-population of patients undergoing oxaliplatin treatment, which was associated with poorer outcome, suggesting this could serve as a marker of oxaliplatin response. C/C or C/T genotype in ERCC1 rs11615 locus decreased benefit from oxaliplatin.

Targeted Therapy in Biliary Tract Cancers.

OPINION STATEMENT: A paradigm shift towards molecular-based, personalized cancer therapeutics has occurred in recent years and a number of targeted drugs have emerged. Various targeted therapies like erlotinib, trastuzumab, and cetuximab have been approved in lung, breast, and colon cancers, respectively. Numerous clinical trials involving targeted drugs in biliary tract cancers are currently in progress, though none have been approved for this disease. Biliary tract cancers are divided into separate entities both anatomically and in terms of pathogenesis but are grouped together in most trials given their rarity. Combination chemotherapy involving cisplatin and gemcitabine is the current standard of care in the metastatic setting. In this review, we will discuss the various molecular pathways implicated in biliary tract cancers and potential therapeutic targets.

Targeting angiogenesis in squamous non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, and can be further classified as nonsquamous carcinoma (including adenocarcinoma, which accounts for 40 % of NSCLCs) and squamous NSCLC, which makes up 30 % of NSCLC cases. The emergence of inhibitors of epidermal growth factor receptors, anaplastic lymphoma kinase, and vascular endothelial growth factors (VEGF) in the last decade has resulted in steady improvement in clinical outcomes for patients with advanced lung adenocarcinoma. However, improvements in the survival of patients with squamous NSCLC have remained elusive, presenting an urgent need for understanding and investigating therapeutically relevant molecular targets, specifically in squamous NSCLC. Although anti-VEGF therapy has been studied in squamous NSCLC, progress has been slow, in part due to issues related to pulmonary hemorrhage. In addition to these safety concerns, several phase III trials that initially included patients with squamous NSCLC failed to demonstrate improved overall survival (primary endpoint) with the addition of antiangiogenic therapy to chemotherapy compared with chemotherapy alone. Angiogenesis is an established hallmark of tumor progression and metastasis, and the role of VEGF signaling in angiogenesis is well established. However, some studies suggest that, while inhibiting VEGF signaling may be beneficial, prolonged exposure to VEGF/VEGF receptor (VEGFR) inhibitors may allow tumor cells to utilize alternative angiogenic mechanisms and become resistant. As a result, agents that target multiple angiogenic pathways simultaneously are also under evaluation. This review focuses on current and investigational antiangiogenic targets in squamous NSCLC, including VEGF/VEGFRs, fibroblast growth factor receptors, platelet-derived growth factor receptors, and angiopoietin. Additionally, clinical trials investigating VEGF- and multi-targeted antiangiogenic therapies are discussed.

Novel drugs targeting the epidermal growth factor receptor and its downstream pathways in the treatment of colorectal cancer: a systematic review.

Colorectal cancer is the second most common malignancy among men and women in the United States, and the 5-year survival rate remains poor despite recent advances in chemotherapy and targeted agents. The mainstay of therapy for advanced disease remains the cytotoxic chemotherapy including 5-FU, irinotecan, and oxaliplatin. The USFDA approval and introduction of targeted therapies, including cetuximab and panitumumab (monoclonal antibodies targeting the epidermal growth factor receptor (EGFR)) and bevacizumab (monoclonal antibody targeting the vascular epithelial growth factor (VEGF)), has improved the median survival of patients with metastatic colorectal cancer to around 24 months. Clearly, better and more efficacious drugs are needed, and target-specific agents remain the future of cancer treatment. On this front, rapid advances are being made, which are likely to change the future of the management of metastatic colorectal cancer. However, absence of specific biomarkers for the use of targeted agents, in the subset of population who will benefit from the treatment, remains a major drawback. In this paper, we review agents that are in phases 1 and 2 clinical development, specifically targeting the EGFR and its subsequent downstream pathways.