Deepa Rangachari

Brain metastases in patients with EGFR-mutated or ALK-rearranged non-small-cell lung cancers

INTRODUCTION Brain metastases (BM) are common in non-small-cell lung cancer (NSCLC). However, the baseline incidence and evolution of BM over time in oncogene-driven NSCLCs are seldom reported. In this study, we evaluated the frequency of BM in patients with epidermal growth factor receptor (EGFR)-mutated or anaplastic lymphoma kinase (ALK)-rearranged NSCLC. METHODS The presence of BM, clinicopathologic data, and tumor genotype were retrospectively compiled and analyzed from a cohort of 381 patients. RESULTS We identified 86 EGFR-mutated (90.7% with metastatic disease; 85.9% received an EGFR inhibitor) and 23 ALK-rearranged (91.3% with metastatic disease; 85.7% received an ALK inhibitor) NSCLCs. BM were present in 24.4% of EGFR-mutated and 23.8% of ALK-rearranged NSCLCs at the time of diagnosis of advanced disease. This study did not demonstrate a difference in the cumulative incidence of BM over time between the two cohorts (EGFR/ALK cohort competing risk regression [CRR] coefficient of 0.78 [95% CI 0.44-1.39], p=0.41). In still living patients with advanced EGFR-mutated NSCLC, 34.2% had BM at 1 year, 38.4% at 2 years, 46.7% at 3 years, 48.7% at 4 years, and 52.9% at 5 years. In still living patients with advanced ALK-rearranged NSCLC, 23.8% had BM at 1 year, 45.5% at 2 years, and 58.4% at 3 years. CONCLUSIONS BM are frequent in advanced EGFR-mutated or ALK-rearranged NSCLCs, with an estimated >45% of patients with CNS involvement by three years of survival with the use of targeted therapies. These data point toward the CNS as an important unmet clinical need in the evolving schema for personalized care in NSCLC.

Management of advanced non-small cell lung cancers with known mutations or rearrangements: latest evidence and treatment approaches

Precision oncology is now the evidence-based standard of care for the management of many advanced non-small cell lung cancers (NSCLCs). Expert consensus has defined minimum requirements for routine testing and identification of epidermal growth factor (EGFR) mutations (15% of tumors harbor EGFR exon 19 deletions or exon 21 L858R substitutions) and anaplastic lymphoma kinase (ALK) rearrangements (5% of tumors) in advanced lung adenocarcinomas (ACs). Application of palliative targeted therapies with oral tyrosine kinase inhibitors (TKIs) in advanced/metastatic lung ACs harboring abnormalities in EGFR (gefitinib, erlotinib, afatinib) and ALK/ROS1/MET (crizotinib) has consistently led to more favorable outcomes compared with traditional cytotoxic agents. In addition, mutations leading to resistance to first-line EGFR and ALK TKIs can now be successfully inhibited by soon to be approved third-generation EGFR TKIs (osimertinib, rociletinib) and second-generation ALK TKIs (ceritinib, alectinib). Notably, increasing feasibility, accessibility, and application of molecular profiling technologies has permitted dynamic growth in the identification of actionable driver oncogenes. Emerging genomic aberrations for which TKIs have shown impressive results in clinical trials and expansion of drug labels for approved agents are awaited include ROS1 rearrangements (1–2% of tumors, drug: crizotinib) and BRAF-V600E mutations (1–3% of tumors, drugs: vemurafenib, dafrafenib + trametinib). Evolving genomic events in which TKI responses have been reported in smaller series include MET exon 14 skipping mutations (2–4% of tumors, drug: crizotinib); high-level MET amplification (1–2% of tumors, drug: crizotinib); RET rearrangements (1% of tumors, drug: cabozantinib); and ERBB2 mutations (2–3% of tumors, drug: afatinib), among others. Unfortunately, the most common genomic event in NSCLC, KRAS mutations (25–30% of tumors), is not targetable with approved or in development small molecule inhibitors. Here, we review currently approved, emerging, and evolving systemic precision therapies matched with their driver oncogenes for the management of advanced NSCLC.

Responses to the multitargeted MET/ALK/ROS1 inhibitor crizotinib and co-occurring mutations in lung adenocarcinomas with MET amplification or MET exon 14 skipping mutation

INTRODUCTION Genomic aberrations involving ALK, ROS1 and MET can be driver oncogenes in lung adenocarcinomas. Identification of tyrosine kinase inhibitors (TKIs) with activity against these tumors and of preclinical systems to model response are warranted. METHODS We analyzed cases with lung adenocarcinomas for representative genomic aberrations, evaluated the response to the multitargeted MET/ALK/ROS1 crizotinib TKI in cases with MET aberrations and profiled lung cancer cell lines with the aforementioned genomic changes. RESULTS Lung cancer cell lines with ALK rearrangement, ROS1 rearrangement or MET amplification had expected in vitro responses to crizotinib and the ALK/ROS1 TKI ceritinib. However, a commercially-available cell line with MET exon 14 skipping mutation and co-occurring PIK3CA-p.Glu545Lys mutation did not respond to crizotinib; suggesting the latter abrogated response. 10% of MET exon 14 skipping mutation co-occurred with PIK3CA mutation in the TCGA cohort. Putative crizotinib-responsive somatic mutations (ALK rearrangements, ROS1 rearrangements, high level MET amplification or MET exon 14 skipping mutations) were present in 10% of lung adenocarcinomas analyzed at our service and in 9.5% of the TCGA lung adenocarcinoma database. One patient each whose advanced tumors harbored high level MET amplification with wild-type PIK3CA or MET exon 14 skipping mutation with PIK3CA-p.Glu542Lys had significant responses to crizotinib; suggesting that PIK3CA co-mutation did not affect clinical response. CONCLUSIONS Approximately 10% of lung adenocarcinomas harbor aberrations that are targetable using the approved multitargeted TKI crizotinib. MET exon 14 skipping mutation predicts for response to MET TKIs in human lung adenocarcinomas but co-occurrence of PIK3CA mutation needs to be better evaluated as a modifier of response to TKI therapy. MET TKIs should not be omitted from MET exon 14 skipping mutated tumors until further preclinical and clinical data can confirm or refute mechanisms of primary or acquired resistance to crizotinib and other MET TKIs in these recalcitrant cancers.

Correlation between Classic Driver Oncogene Mutations in EGFR, ALK, or ROS1 and 22C3–PD-L1 ≥50% Expression in Lung Adenocarcinoma

Introduction: Targeted somatic genomic analysis (EGFR, anaplastic lymphoma receptor tyrosine kinase gene [ALK], and ROS1) and programmed death ligand 1 (PD‐L1) tumor proportion score (TPS) determined by immunohistochemistry (IHC) are used for selection of first‐line therapies in advanced lung cancer; however, the frequency of overlap of these biomarkers in routine clinical practice is poorly reported. Methods: We retrospectively probed the first 71 pairs of patients with lung adenocarcinoma from our institution. They were analyzed for PD‐L1 by IHC using the clone 22C3 pharmDx kit (Agilent Technologies, Santa Clara, CA) and evaluated for co‐occurrence of genomic aberrations and clinicopathologic characteristics. Results: Surgical resection specimens, small biopsy (transbronchial or core needle) samples, and cytologic cell blocks (needle aspirates or pleural fluid) were tested. A PD‐L1 TPS of at least ≥50% was seen in 29.6% of tumors. Of 19 tumors with EGFR mutations, ALK fluorescence in situ hybridization positivity, or ROS1 fluorescence in situ hybridization positivity, 18 had a PD‐L1 TPS less than 50% versus only one tumor with a PD‐L1 TPS of at least 50% (p = 0.0073). Tumors with a PD‐L1 TPS of at least 50% were significantly associated with smoking status compared with tumors with a PD‐L1 TPS less than 50% but were not associated with patient sex, ethnicity, tumor stage, biopsy site, or biopsy type/preparation. Conclusions: PD‐L1 IHC can be performed on routine clinical lung cancer specimens. A TPS of at least 50% seldom overlaps with presence of driver oncogenes with approved targeted therapies. Three biomarker‐specified groups of advanced lung adenocarcinomas can now be defined, each paired with a specific palliative first‐line systemic therapy of proven clinical benefit: (1) EGFR/ALK/ROS1‐affected adenocarcinoma paired with a matched tyrosine kinase inhibitor (˜20% of cases), (2) PD‐L1–enriched adenocarcinoma (TPS ≥50%) paired with anti–PD‐1 pembrolizumab (˜30% of cases), and (3) biomarker‐negative (i.e., EGFR/ALK/ROS1/PD‐L1–negative) adenocarcinoma paired with platinum doublet chemotherapy with or without bevacizumab (˜50% of cases).

Integrating palliative care in oncology: the oncologist as a primary palliative care provider.

AbstractThe provision of comprehensive cancer care in an increasingly complex landscape necessitates that oncology providers familiarize themselves with the application of palliative care. Palliative care is a learnable skill. Recent endeavors in this arena have demonstrated that providing palliative care is part and parcel with providing compassionate and high-quality cancer care, specifically as it pertains to physical and emotional outcomes for patients and their caregivers alike. The basic tenets of providing palliative care emphasize: frequent and honest communication, routine and systematic symptom assessment, integration of spiritual assessments, and early integration of specialized hospice and palliative care resources as a patient’s circumstances evolve. This article will endeavor to review and synthesize recent developments in the palliative care literature, specifically as they pertain to the oncologist as a primary palliative care provider.

EGFR Testing in Advanced Non-Small-Cell Lung Cancer, A Mini-Review.

Expert consensus guidelines have defined minimum requirements for routine testing and identification of classical epidermal growth factor (EGFR) mutations (ie, exon 19 deletions and exon 21 L858R substitution) and anaplastic lymphoma kinase (ALK) rearrangements in advanced non-small-cell lung cancers of adenocarcinoma histology, with the intent of permitting use of these predictive biomarkers to select patients who will derive maximal benefit from approved oral tyrosine kinase inhibitors (TKIs) directed against EGFR and ALK, respectively. However, the practice of precision medicine is incumbent upon optimal tumor sampling, accurate tumor testing, and informed application of results to patient care. We report on a brief review of EGFR testing methodologies (Sanger sequencing, allele-specific polymerase chain reaction, and targeted next-generation sequencing) to identify classical and other (ie, exon 18 G719X, exon 19 insertions, exon 20 insertions, exon 21 L861Q) EGFR mutations; practical considerations (type of tissue/biopsies with different success rates of DNA isolation, and timeliness of result-reporting to facilitate therapeutic decision-making); role of rebiopsy (to identify mechanisms of acquired resistance to first- and second-generation EGFR TKIs, most importantly EGFR-T790M); and clinical vignettes highlighting the nuances of testing in day-to-day practice.

Mutations in TP53, PIK3CA, PTEN and other genes in EGFR mutated lung cancers: Correlation with clinical outcomes

INTRODUCTION The degree and duration of response to epidermal growth factor receptor (EGFR) inhibitors in EGFR mutated lung cancer are heterogeneous. We hypothesized that the concurrent genomic landscape of these tumors, which is currently unknown in view of the prevailing single gene assay diagnostic paradigm in clinical practice, could play a role in clinical outcomes and/or mechanisms of resistance. METHODS We retrospectively probed our institutional lung cancer database for tumors with EGFR kinase domain mutations that were also evaluated by more comprehensive molecular profiling, and evaluated tumor response to EGFR tyrosine kinase inhibitors (TKIs). RESULTS Out of 171 EGFR mutated tumor-patient cases, 20 were sequenced using at least a limited comprehensive genomic profiling platform. 50% harbored concurrent TP53 mutation, 10% PIK3CA mutation, 5% PTEN mutation, among others. The response rate to EGFR TKIs, the median progression-free survival (PFS) to TKIs, the percentage of EGFR-T790M TKI resistance and survival had higher trends in EGFR mutant/TP53 wild-type cases when compared to EGFR mutant/TP53 mutant tumors (all p >0.05 without statistical significance); with a significantly longer median PFS in EGFR-exon 19 deletion mutant/TP53 wild-type cancers treated with 1st generation EGFR TKIs (p=0.035). CONCLUSIONS Concurrent mutations, specifically TP53, are common in EGFR mutated lung cancer and may alter clinical outcomes. Additional cohorts will be needed to determine if comprehensive molecular profiling adds clinically relevant information to single gene assay identification in oncogene-driven lung cancers.

De novo pulmonary small cell carcinomas and large cell neuroendocrine carcinomas harboring EGFR mutations: Lack of response to EGFR inhibitors

INTRODUCTION Epidermal growth factor receptor (EGFR) mutations are present in 10-20% of all non-small-cell lung cancers and predict for response to EGFR tyrosine kinase inhibitors (TKIs). However, the incidence of these mutations and their ability to predict response to TKIs in high-grade pulmonary neuroendocrine carcinomas [i.e. small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC)] is unknown. METHODS The presence of EGFR mutations, clinicopathologic and anti-cancer therapy response data were retrospectively compiled and analyzed from a cohort of 608 patients-lung tumors to identify EGFR mutated high-grade pulmonary neuroendocrine carcinomas. We identified 126 EGFR-mutated (21.8% of 578 successful genotyped cases) lung cancers and only 2 (1.6%) were high-grade neuroendocrine carcinomas. RESULTS Case one was of a 63 year-old white never smoker woman with extensive stage SCLC harboring EGFR-delL747_P753insS but without EGFR protein expression. After progression on carboplatin/etoposide, the patient was treated with erlotinib and developed progressive disease with a survival <3 months from start of erlotinib. Case two was of a 73 year-old Asian 30 pack-year smoker man with metastatic LCNEC harboring EGFR-delL747_P753insQS and also lacking EGFR protein expression. The patient received first line therapy with erlotinib and had progressive disease with a survival of 4 months. CONCLUSIONS The lack of response to EGFR TKIs in EGFR mutated de novo SCLC and LCNEC reported here may indicate that tumor differentiation affects tumor dependency on EGFR as a driver oncogene.

Targeting the Immune System in the Treatment of Non-Small-Cell Lung Cancer

Opinion statementNon-small-cell lung cancer (NSCLC) remains the most common cause of cancer-related death worldwide. Traditional cytotoxic agents and their attendant toxicities have remained the mainstay of systemic therapy for this disease, until now. With the identification of novel molecular and immune cancer-specific aberrancies, molecular agents and immunotherapies have garnered increasing attention as attractive targets, with the potential for improved outcomes while mitigating systemic toxicities seen with traditional cytotoxic agents. Despite a longstanding interest in immunotherapy for the treatment of NSCLC, results of prior studies of therapeutic vaccines have failed to show durable or convincingly meaningful clinical responses. However, newer trials of therapeutic vaccines and checkpoint inhibitors have yielded more promising results. In particular, the checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed death-1 (PD-1) pathway have shown meaningful clinical responses with manageable toxicities. Large phase III studies are underway, the results of which have the potential to revolutionize the way in which we care for patients with NSCLC. More studies also are needed to investigate the potentially synergistic effects of traditional and immune-based therapies. Given their unique antineoplastic effects, novel immune-specific clinical endpoints also are actively being investigated.

De novo ALK kinase domain mutations are uncommon in kinase inhibitor-naïve ALK rearranged lung cancers

INTRODUCTION Anaplastic lymphoma kinase (ALK) rearranged lung adenocarcinomas are responsive to the multitargeted ALK inhibitor crizotinib. One of the common mechanisms of resistance to crizotinib is the acquisition of ALK kinase domain mutations. However, the presence of ALK mutations in crizotinib-naïve tumors has not been widely reported and it is unclear if de novo ALK mutations affect the response to crizotinib. METHODS We analyzed preclinical models of ALK rearranged lung cancers that were sensitive/resistant to ALK inhibitors, probed our institutional and other lung cancer databases for tumors with ALK kinase domain mutations, and evaluated tumor response to crizotinib. RESULTS ALK rearranged cell lines with ALK kinase domain mutations were heterogeneously less inhibited by increasing concentrations of crizotinib than cells driven solely by EML4-ALK fusions. Previous ALK rearranged lung cancer cohorts did not report ALK kinase mutations in inhibitor-naïve tumors. We identified one TKI-naïve ALK rearranged tumor with an ALK kinase domain mutation: ALK-S1206F (mutations at ALK-S1206 shifted crizotinib inhibitory curves only minimally in preclinical models). The never smoker whose tumor harbored de novo EML4-ALK-E5;A20+ALK-S1206F only achieved a 4-month radiographic response to crizotinib 250mg twice daily. CONCLUSIONS Combining data from our and prior cohorts, ALK kinase domain mutations were uncommon events (<3% of cases) in ALK inhibitor-naïve ALK rearranged lung adenocarcinomas but their effect on intrinsic resistance to ALK inhibitors should be better evaluated.