Squamous cell lung cancer

EGFR-mutant lung cancers (LC) serve as the prototype oncogene-driven cancer and mechanisms of resistance to EGFR therapy are well-established. Selective pressure of EGFR inhibitors can induce lineage plasticity to escape oncogene-dependence. While we have shown EGFR/TP53/RB1-mutations are necessary but insufficient to induce small cell transformation, no other genomic signatures and transcriptomic/epigenomic effectors that induce transformation have been identified.

Using parallel exome sequencing, bulk RNA sequencing, and bisulfite sequencing, we will characterize the biomarkers of transformation in EGFR/TP53/RB1-mutant LC and mixed adenocarcinoma/squamous cell tumors. We will also utilize single-cell RNA sequencing to identify the transcriptional changes associated with transformation and to identify distinct cell types within a heterogenous tumor. We will reconstruct a phenotypic landscape to identify subclones in a transitional state between histologies. The information obtained from these studies will nominate novel biomarkers of lineage plasticity that will be validated and proposed for study in clinical trials.

Despite high tumor response rates, patients treated with osimertinib inevitably develop disease progression. Mechanisms of both intrinsic, adaptive, and acquired drug resistance remain incompletely understood on a genomic and proteomic level. Our overall objective is to find new targeted treatments and drug combinations that can tackle cancer evolution and drug resistance.

We seek to:

1. Understand biological determinants of response prior to therapy (poor prognosis features)
2. Utilize correct combination therapies in the first line to enhance response, based on biological features of subpopulations present at the start
3. Reprogram cells toward a more drug-sensitive state through understanding network plasticity.

More specifically, our aims are:

1. To define the genomic and proteomic characteristics of drug-tolerant persister cells (DTPCs) under dynamic treatment with osimertinib. Our goal is to identify new vulnerabilities in EGFR-mutant tumors which, when therapeutically targeted, can maximize the depth and duration of benefit to first-line osimertinib therapy.
2. To decipher mechanisms of altered cell cycle progression and osimertinib-induced DNA damage that drive tumor progression.

We have assembled a collaborative, multi-disciplinary team of laboratory scientists and clinical investigators combined with cutting edge technologies to assess genetic and proteomic heterogeneity at the single cell level, access to a robust pipeline of patient samples, and strong preliminary data to support our studies. The proposed aims are expected to define the molecular determinants of tumor heterogeneity and to develop rational therapeutic strategies for delaying / overcoming resistance. These synergistic aims are highly relevant to the current landscape of EGFR-mutant lung cancer.

Statement of the Problem: Cancer develops in a sequenced manner. Patches of lung cells gain the ability to multiply faster than their neighboring normal cells by acquiring mutations. These patches of cells are called “premalignant lesions" (PMLs). Some of these lesions may eventually become cancer. Knowledge about how some PMLs may develop into lung cancer is central to developing tools for Cancer Interception—interrupting the cancer development process and blocking progression to advanced metastatic disease. However, we lack effective lung cancer interception approaches due to our incomplete understanding of the earliest molecular events associated with the development of lung cancer, as well as the challenge in developing personalized tools for early detection and prevention.

Proposed Solution: The Dream Team will use a holistic approach to understand the genetics, immunology, radiological (imaging) profile, and treatment response of patients who show evidence of abnormal lung tissue that puts them at high risk to develop lung cancer. The Team has access to unique groups of patient populations (adenocarcinoma—ADC and squamous cell carcinoma—SCC) with signs of lung cancer risk, and has assembled a collection of blood and tissue specimens from these individuals. The main objective of the Team is to understand how lung cancer develops and test methods that will block the development of cancer. Their three-pronged approach to solve this problem will include:

• Creation of a molecular pre-cancer genome atlas (PCGA) of the lung with the goal of identifying which types of precancerous lung tissue require aggressive treatment and which treatments will block the development of these abnormal lesions to invasive lung cancer.
• Development of two diagnostic tools that can be directly applied in the clinic for simple, yet accurate, detection of early lung cancer: 1) the use of nasal swabs, blood tests, and imaging to confirm whether lung abnormalities found on chest imaging are lung cancer or benign lung disease. 2) blood tests that can identify patients at the earliest stages of lung cancer recurrence, thus enabling their timely and effective intervention with therapies such as those that boost the immune system.
• Development of tests to identify which individuals are most likely to benefit from a number of treatment strategies to intercept lung cancer, including emerging immunotherapies.

Statement of the Problem: Currently, low dose CT (LDCT) screening for lung cancer is recommended for high-risk individuals, defined as current or former smokers (quit within the past 15 years) with a 30-or-more pack-year smoking history, 55 to 74 years of age, and with no evidence of lung cancer. However, uptake of LDCT screening has been impeded by high rates of false-positive results, which in turn add significant physical and emotional stress to patients as well as additional healthcare costs. Since LDCT is now commonly available, lung nodules detected in LDCT scans are plentiful, but imprecise guidelines for care make it a challenge to ensure quality follow-up and expedited diagnoses for those with lung cancer. Furthermore, screening is not available for those who don’t meet the screening criteria (younger age or low smoking history) when they are the exact population among whom lung cancer rates are rising.

Proposed Solution: Leveraging expertise of academic research centers (Massachusetts General Hospital, Broad Institute, and Stanford University) and a non-profit managed-care consortium (Kaiser Permanente), the Dream Team will develop a test called the Lung Cancer Interception Assay (LCIA) to complement LDCT screening.

The proposal is novel in that it will develop complex computational algorithms to combine high-sensitivity/high-accuracy blood-based molecular biomarkers with image-based biomarkers to create the  LCIA assay. At the end of the award period, a streamlined product, the LCIA, will be ready to use in population-level definitive trials for the early detection of lung cancer.

One of the challenges for early detection and prevention of lung squamous cell carcinoma is the lack of understanding of the molecular and cellular changes that cause initiation and progression of this disease. Airway premalignant lesions are the precursors of lung squamous cell carcinoma and can be detected and monitored by autofluorescence bronchoscopy. However, many of these lesions will regress without clinical intervention, and only a subset will progress to invasive carcinoma. The goal of this study is to characterize the landscape of somatic mutations in airway premalignant lesions and to develop an early detection biomarker using targeted DNA sequencing that can predict risk of lesion progression. Ultra-deep whole-exome sequencing will be performed on a previously collected cohort of airway premalignant lesions from high-risk smokers that have been sampled over time, characterized histologically, and classified into those that are stable, regress, or progress. Significantly mutated genes, recurrent copy number changes, and mutational signatures will be identified, and a determination will be made whether they are associated with lesion histology or progression or regression status. Finally, the findings from this study will be combined with the driver genes from The Cancer Genome Atlas (TCGA) to build a targeted DNA sequencing panel. This panel will serve as a rapid and relatively inexpensive method for monitoring premalignant lesions from patients over time and can be used in a clinical trial to assess the ability of autofluorescence bronchoscopy in combination with molecular profiling to stratify patients and serve as a companion diagnostic in chemoprevention trials.

The overarching goal of the project is to develop a new technology for accurate and cost-effective lung cancer screening in current/former smokers. Lung cancer is curable if detected early. However, there are no robust screening techniques with options such as CT scans fraught with cost, harms, and a high false positive rate. Dr. Backman and his group hope to transform the clinical practice of lung cancer screening by exploiting field carcinogenesis, the concept that the genetic/environmental milieu that results in lung tumor impacts upon the entire aerodigestive mucosa including the buccal mucosa, which was referred to as a “molecular mirror” of lung carcinogenesis.

Their data show that the alteration of nanoscale architecture of buccal cells is exquisitely sensitive to lung field carcinogenesis and may serve as a robust biomarker for lung cancer. These nanoarchitectural changes can be detected in a practical and highly accurate fashion via a new technology, partial wave spectroscopic (PWS) microscopy (‘nanocytology’).

In the proposed study, they will conduct a blinded validation case-control trial to determine the sensitivity and specificity of buccal nanocytology for lung cancer. They will evaluate the ability of the test to identify patients who have lung cancer and how many patients with lung cancer would be missed using this technique. They will perform a subgroup analysis for Stage I lung cancers. They will assess the potential confounding effects of smoking frequency and time of cessation and other aerodigestive malignancies.

This project will provide the requisite data for the future definitive multicenter validation trial followed by FDA submission.