Lung Cancer

Lung cancer is the leading cause of cancer-related mortality in the U.S. and worldwide. Histology is used to diagnose lung cancer. Molecular markers are useful for informing therapeutic decisions in patients with advanced stages of adenocarcinoma.

Tabs Content

Clinical Overview

Key Points

Molecular Markers in Lung Cancer

The presence of molecular markers in nonsmall cell lung cancer (NSCLC) is associated with responsiveness to targeted therapies (eg, tyrosine kinase inhibitors [TKIs], monoclonal antibodies) for patients with adenocarcinoma or mixed adenocarcinoma histology. Simultaneous ordering of testing for EGFR, ALK, and ROS1 alterations is recommended for advanced stage adenocarcinoma or mixed adenocarcinoma subtypes. Mutational testing may be considered on small samples even in the absence of adenocarcinoma, as sampling bias may occur and mixed adenocarcinoma tumors could otherwise be missed. Minimum testing should include EGFR mutation and ALK and ROS1 rearrangement detection (American Society of Clinical Oncology [ASCO]/College of American Pathologists [CAP], 2014; International Association for the Study of Lung Cancer [IASLC]/Association for Molecular Pathology [AMP], 2013; National Comprehensive Cancer Network [NCCN] NSCLC guideline, 2018). Additionally, immunohistochemistry (IHC) testing for programmed death-ligand 1 (PD-L1) expression in patients with metastatic NSCLC (squamous and nonsquamous morphology) is recommended. Guidelines strongly advise using multiplex or next generation sequencing (NGS), which detects both common and rare driver alterations (eg, BRAF, MET, RET, HER2 alterations) to optimize patient therapy (NCCN NSCLC guideline, 2018).

EGFR

EGFR (Epidermal Growth Factor Receptor) Gene
Pathophysiology	Receptor tyrosine kinase is involved in cell proliferation and survival
Mutations	Increased sensitivity to TKIs associated with exon 19 deletions or exon 21 (L858R) substitution Decreased sensitivity to TKIs associated with T790M mutation – usually develops when treatment resistance occurs Lack of EGFR mutations (wild type) Mutation status of EGFR does not appear to predict response to treatment with EGFR monoclonal antibody (cetuximab) Presence of EGFR mutation is usually mutually exclusive for ALK translocation
Population characteristics associated with mutation	10-15% of adenocarcinomas Associated with Asian ethnicity, female sex, and nonsmoking or light smoking status
ARUP tests available Lung Cancer Panel 2008894 – includes EGFR, ALK, and ROS1 Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK, and ROS1 EGFR Mutation Detection by Pyrosequencing 2002440 EGFR T790M Mutation Detection in Circulating Tumor DNA by Digital Droplet PCR 2012868 Solid Tumor Mutation Panel 2007991	Mutational analysis is preferred over gene amplification (ASCO/CAP, 2014; IASLC/AMP, 2013) Mutational testing should detect mutations in samples with at least 50% tumor cells (25% mutant alleles), although laboratories are strongly encouraged to use more sensitive tests that can detect mutations in specimens with as little as 10% tumor cells IHC and FISH are not recommended Consider monitoring for acquired resistance to early generation TKIs for development of EGFR T790M mutation (using blood plasma or cerebrospinal fluid)

ALK

ALK (Anaplastic Lymphoma Receptor Tyrosine Kinase) Gene
Pathophysiology	Fusion of ALK gene with echinoderm microtubule-associated protein-like-4 (EML-4) or other fusion partners mediates ligand-independent oligomerization of ALK protein, resulting in ALK kinase activation Functions as potent oncogenic driver
Translocations	Fusion partner genes include EML4, HIP1, KIF5B, KLC1, TPR Certain ALK rearrangements are associated with increased sensitivity to specific TKIs (eg, crizotinib) and decreased sensitivity to EGFR TKIs Presence of ALK gene rearrangements is generally mutually exclusive of EGFR and KRAS gene mutations
Population characteristics associated with mutation	4-7% of adenocarcinomas Associated with young age, male sex, nonsmoking or light smoking status, signet rings, and mucinous subtypes
ARUP tests available Lung Cancer Panel 2008894 – includes EGFR, ALK, and ROS1 Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK, and ROS1 ALK (D5F3) with Interpretation by Immunohistochemistry 2007324 ALK (D5F3) by Immunohistochemistry with Reflex to ALK Gene Rearrangements by FISH 2011431 ALK Gene Rearrangements by FISH, Lung 2006102	Detection of mutation is a prerequisite for crizotinib treatment in U.S. IHC detects protein expression and is a surrogate marker for ALK gene fusion FISH interpretation may be challenging due to small inversions involving chromosome 2p (2p21 and 2p23) and does not identify translocation partner

ALK (Anaplastic Lymphoma Receptor Tyrosine Kinase) Gene

Pathophysiology

Fusion of ALK gene with echinoderm microtubule-associated protein-like-4 (EML-4) or other fusion partners mediates ligand-independent oligomerization of ALK protein, resulting in ALK kinase activation

Functions as potent oncogenic driver

Translocations

Fusion partner genes include EML4, HIP1, KIF5B, KLC1, TPR

Certain ALK rearrangements are associated with increased sensitivity to specific TKIs (eg, crizotinib) and decreased sensitivity to EGFR TKIs

Presence of ALK gene rearrangements is generally mutually exclusive of EGFR and KRAS gene mutations

Population characteristics associated with mutation

4-7% of adenocarcinomas

Associated with young age, male sex, nonsmoking or light smoking status, signet rings, and mucinous subtypes

ARUP tests available

Lung Cancer Panel 2008894 – includes EGFR, ALK, and ROS1

Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK, and ROS1

ALK (D5F3) with Interpretation by Immunohistochemistry 2007324

ALK (D5F3) by Immunohistochemistry with Reflex to ALK Gene Rearrangements by FISH 2011431

ALK Gene Rearrangements by FISH, Lung 2006102

Detection of mutation is a prerequisite for crizotinib treatment in U.S.

IHC detects protein expression and is a surrogate marker for ALK gene fusion

FISH interpretation may be challenging due to small inversions involving chromosome 2p (2p21 and 2p23) and does not identify translocation partner

ROS1

ROS1 (c-ros Oncogene 1, Receptor Tyrosine Kinase) Gene
Pathophysiology	Receptor tyrosine kinase is involved in cell proliferation ROS1 gene rearrangement and fusion with multiple known partners mediates constitutive ROS1 kinase activation Inhibition of tyrosine kinase activity diminishes tumor growth
Translocations	Fusion partner genes include CD74, EZR, FIG, KDELR2, LRIG3, SDC4, SLC34A2, TPM3 Generally associated with increased sensitivity to TKIs (eg, crizotinib) and decreased sensitivity to EGFR TKIs Presence of ROS1 gene rearrangements is generally mutually exclusive of EGFR and KRAS gene mutations
Population characteristics associated with mutation	1-2% of adenocarcinomas Associated with Asian ethnicity, young age, nonsmoking or light smoker status
ARUP tests available Lung Cancer Panel 2008894 – includes EGFR, ALK, and ROS1 Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK, and ROS1 ROS1 with Interpretation by Immunohistochemistry with Reflex to FISH if Equivocal 2008414 ROS1 by FISH 2008418	IHC detects protein expression (surrogate marker for ROS1 gene fusion) and is more cost effective and efficient when compared to FISH, although FISH is indicated for equivocal results by IHC FISH detects gene rearrangements

ROS1 (c-ros Oncogene 1, Receptor Tyrosine Kinase) Gene

Pathophysiology

Receptor tyrosine kinase is involved in cell proliferation

ROS1 gene rearrangement and fusion with multiple known partners mediates constitutive ROS1 kinase activation

Inhibition of tyrosine kinase activity diminishes tumor growth

Translocations

Fusion partner genes include CD74, EZR, FIG, KDELR2, LRIG3, SDC4, SLC34A2, TPM3

Generally associated with increased sensitivity to TKIs (eg, crizotinib) and decreased sensitivity to EGFR TKIs

Presence of ROS1 gene rearrangements is generally mutually exclusive of EGFR and KRAS gene mutations

Population characteristics associated with mutation

1-2% of adenocarcinomas

Associated with Asian ethnicity, young age, nonsmoking or light smoker status

ARUP tests available

Lung Cancer Panel 2008894 – includes EGFR, ALK, and ROS1

Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK, and ROS1

ROS1 with Interpretation by Immunohistochemistry with Reflex to FISH if Equivocal 2008414

ROS1 by FISH 2008418

IHC detects protein expression (surrogate marker for ROS1 gene fusion) and is more cost effective and efficient when compared to FISH, although FISH is indicated for equivocal results by IHC

FISH detects gene rearrangements

PD-L1

Programmed Death-Ligand 1 (PD-L1)
Pathophysiology	Control T-cell coinhibitory receptor and ligand function as immune checkpoint PD-L1 – ligand for PD-1 PD-L1 expression facilitates immune system evasion by inhibiting T-cell activation PD-1 is expressed by a variety of solid tumors, including NSCLC
ARUP tests available PD-L1 22C3 IHC for NSCLC with Interpretation, pembrolizumab (KEYTRUDA) 2013284 PD-L1 28-8 pharmDx by Immunohistochemistry with Interpretation, nivolumab (OPDIVO) 2013684	Detection of PD-L1 expression by immunohistochemistry may predict response to immunotherapy PD-L1 22C3 aids in prediction of response to pembrolizumab (KEYTRUDA) as first- or second-line therapy for patients with NSCLC PDL1 28-8 aids in prediction of response to nivolumab for patients with nonsquamous NSCLC
PD-1, programmed cell death protein 1

Programmed Death-Ligand 1 (PD-L1)

Pathophysiology

Control T-cell coinhibitory receptor and ligand function as immune checkpoint

PD-L1 – ligand for PD-1
PD-L1 expression facilitates immune system evasion by inhibiting T-cell activation
PD-1 is expressed by a variety of solid tumors, including NSCLC

ARUP tests available

PD-L1 22C3 IHC for NSCLC with Interpretation, pembrolizumab (KEYTRUDA) 2013284

PD-L1 28-8 pharmDx by Immunohistochemistry with Interpretation, nivolumab (OPDIVO) 2013684

Detection of PD-L1 expression by immunohistochemistry may predict response to immunotherapy

PD-L1 22C3 aids in prediction of response to pembrolizumab (KEYTRUDA) as first- or second-line therapy for patients with NSCLC

PDL1 28-8 aids in prediction of response to nivolumab for patients with nonsquamous NSCLC

PD-1, programmed cell death protein 1

KRAS

KRAS (v-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog I) Gene
Pathophysiology	RAS family of genes regulates signal conduction pathways that control cell growth 3 distinct genes – HRAS, NRAS, and KRAS
Mutation	Almost all RAS mutations in NSCLC are in KRAS gene Generally associated with decreased sensitivity to EGFR TKIs and overall poor prognosis Mutations in both EGFR and KRAS genes are associated with decreased sensitivity to TKIs despite the presence of EGFR mutation Presence of KRAS gene mutations is generally mutually exclusive of EGFR mutations and ALK rearrangements
Population characteristics associated with mutation	25-30% of adenocarcinomas Associated with mucinous subtype and current smoker status
ARUP tests available Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK (D5F3), and ROS1 KRAS Mutation Detection 0040248 Solid Tumor Mutation Panel 2007991	Mutation testing is test of choice Testing for KRAS is not recommended as a sole determinant for EGFR-directed therapy

KRAS (v-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog I) Gene

Pathophysiology

RAS family of genes regulates signal conduction pathways that control cell growth

3 distinct genes – HRAS, NRAS, and KRAS

Mutation

Almost all RAS mutations in NSCLC are in KRAS gene

Generally associated with decreased sensitivity to EGFR TKIs and overall poor prognosis

Mutations in both EGFR and KRAS genes are associated with decreased sensitivity to TKIs despite the presence of EGFR mutation

Presence of KRAS gene mutations is generally mutually exclusive of EGFR mutations and ALK rearrangements

Population characteristics associated with mutation

25-30% of adenocarcinomas

Associated with mucinous subtype and current smoker status

ARUP tests available

Lung Cancer Panel with KRAS 2008895 – includes KRAS, EGFR, ALK (D5F3), and ROS1

KRAS Mutation Detection 0040248

Solid Tumor Mutation Panel 2007991

Mutation testing is test of choice

Testing for KRAS is not recommended as a sole determinant for EGFR-directed therapy

BRAF

BRAF (B-Raf Proto-Oncogene) Gene
Pathophysiology	Activates MAPK pathway, links with tyrosine kinases
Mutation	Generally associated with increased sensitivity to TKIs (eg, vemurafenib)
Population characteristics associated with mutation	1-4% of adenocarcinomas Associated with female sex and smoking
ARUP tests available BRAF Codon 600 Mutation Detection by Pyrosequencing 2002498 BRAF V600E Mutation Detection in Circulating Cell-Free DNA by Digital Droplet PCR 2013921 Solid Tumor Mutation Panel 2007991	BRAF codon 600 mutation testing by pyrosequencing detects most common mutation BRAF V600E mutation detection in circulating cell-free DNA by digital droplet PCR also available

RET

RET (Ret Proto-Oncogene) Gene
Pathophysiology	RET gene rearrangement and fusion with multiple known partners mediates constitutive RET kinase activation
Translocations	Fusion partner genes include CCDC6, CUX1, KIF5B Generally associated with sensitivity to TKIs (eg, vandetanib, cabozantinib); decreased sensitivity to EGFR TKIs
Population characteristics associated with mutation	1-2% of adenocarcinomas
ARUP test available RET Gene Rearrangements by FISH 2012654	IHC has not been established for RET detection FISH detects gene rearrangements; does not identify translocation partner

MET

MET (Met Proto-Oncogone) Gene
Pathophysiology	Encodes for MET tyrosine kinase receptor
Mutation	Certain MET mutations are associated with Acquired resistance to EGFR inhibitors in 5-20% of patients with EGFR-mutated tumors Tumor progression Possible response to specific TKIs (eg, crizotinib)
Population characteristics associated with mutation	2-4% of adenocarcinomas
ARUP tests available MET Gene Amplification by FISH 2013082 c-MET by Immunohistochemistry 2008652	FISH detects gene amplification IHC detects c-MET overexpression

Diagnosis

Indications for Testing

New pulmonary mass

Laboratory Testing

Serum testing is not helpful in diagnosing lung cancer; however, baseline testing (eg, CBC with differential, liver function) may be performed as a general screen for metastasis
Other testing
- Molecular testing – see Key Points
- Neuron-specific enolase (NSE), serum – may have diagnostic value for small cell lung cancer (SCLC)

Imaging Studies

Chest x-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI) provide basis for initial testing

Histology

Invasive testing to obtain tissue is necessary for diagnosis – sampling is performed by
- Bronchoscopic biopsy
- Mediastinal node sampling
- Fine needle aspiration using CT guidance
- Open lung biopsy
- Fine needle aspiration using endobronchial ultrasound (EBUS)
Do not use sputum cytology to evaluate patients with peripheral lung lesions (Choosing Wisely: 20 Things Physicians and Patients Should Question, 2017; American Society for Clinical Pathology)

Immunohistochemistry

Should be used adjunctively and interpreted in clinical context
Squamous cell carcinoma (SCC)
- Usually negative for CK 7, CK 20, TTF-1
- Does not typically require immunohistochemical staining for diagnosis
Primary adenocarcinoma and bronchioalveolar carcinoma
- Positive for CK 7, napsin A, and thyroid transcription factor-1 (TTF-1); negative for CK 20
- Primary mucinous adenocarcinoma – positive for CK 7 and CK 20, negative for TTF-1
SCLC and neuroendocrine carcinomas
- Typically negative for CK 7, CK 20
- Typically positive for keratin, epithelial membrane antigen, and TTF-1
- Positive for neuroendocrine markers such as chromogranin A, CD56 (NCAM), synaptophysin, NSE
Dysregulation in tumor progression, therapeutic target – c-MET

Markers used to differentiate cancers

Markers	Use	Comments
p63 and CK 5,6 – positive TTF-1 – negative	Differentiating poorly differentiated SCC from SCLC	Supports SCC
CEA-P, b72.3, Ber-EP4, MOC-31, and TTF-1	Differentiating NSCLC adenocarcinoma from mesothelioma	Positive in NSCLC Negative in mesothelioma
Micro RNA (mRNA) expression	Differentiating NSCLC from SCLC
CK 7+/CK 20-, TTF-1+ – pulmonary CK 7-/CK20+, TTF-1- – colorectal	Differentiating metastatic adenocarcinomas
CDX2	Differentiating primary lung tumors from metastatic gastrointestinal tumors	Specific for gastrointestinal tumors

Molecular markers
- Most useful for therapeutic decisions in patients with advanced stages of adenocarcinoma and mixed adenocarcinoma subtypes (ASCO/CAP, 2014; IASLC/AMP, 2013) – see Key Points

Solitary Pulmonary Nodule

Definition – single, well-circumscribed opacity measuring up to 3 cm in diameter and completely surrounded by aerated wing
Usually found incidentally on chest radiograph (0.09-0.2% of all radiographs)
- Incidence of cancer ranges from 10-70% (Kikano, 2015)
Histologic diagnosis may be necessary in the following cases:
- Patient is ≥35 years
- Nodule is ≥8 mm diameter
- Growth of lesion
- Lack of calcification
- Adenopathy
- Positive positron emission tomography (PET) scan
- No previous imaging to review in order to determine if nodule has changed in size

Prognosis

Markers
- Mutations in genes – AKT1, ALK, BRAF, EGFR, ERBB2, ERBB4, KRAS, NRAS, PIK3CA
- Gene fusions that result in translocations – ALK, RET, ROS1
  - Refer to Key Points
  - Used to establish eligibility for therapies such as tyrosine kinase and ALK inhibitors
- Programmed cell death protein 1 (PD-1) and PD-L1
  - Refer to Key Points
Promising markers
- Cytokeratin-19 fragment (CYFRA 21-1) (Cho, 2007)
  - Most sensitive tumor marker for NSCLC (particularly squamous)
    - May also be elevated in urological, gastrointestinal, and gynecological tumors
  - Uses
    - Prognostication
      - Elevated pretreatment level – associated with unfavorable prognosis
    - Monitoring
      - Decreasing levels predict objective response to treatment
- NSE
  - High specificity for SCLC
  - May be useful in assessing prognosis in NSCLC and SCLC
  - Currently in clinical use, but prognostic value has not been validated in high-level study
- p53 – tumor suppressor protein
  - Presence in patients with NSCLC is prognostic of short survival time and potential benefit from adjuvant chemotherapy
- Progastrin-releasing peptide (ProGRP) – SCLC
- CA-125 (available as an immunohistochemical stain) – NSCLC
- STK11 – adenocarcinoma
- Tumor M2-PK (TU M2-PK) – all types
- BCL-2 (available as an immunohistochemical stain) – SCLC
- ERCC1 expression – high level
- RRM1 expression – high level

Differential Diagnosis

Solitary pulmonary nodule
- Granuloma
  - Mycobacterium tuberculosis
  - Yeasts – Coccidiomycosis, Histoplasma, Cryptococcus
  - Molds – Aspergillus
- Hamartoma
- Round pneumonia
- Bronchogenic cyst
- Pulmonary infarction
- Focal hemorrhage
- Arteriovenous malformation
- Other malignancy
  - Carcinoid tumor
  - Lung metastases
  - Lymphoma
Mass
- Pneumonia
- Metastatic tumor
- Fibrotic lung disease
- Mesothelioma
- Other lung tumor
  - Lymphoma
  - Carcinoid

Screening

Screening recommendations
- Annual screening by low-dose CT scan is indicated for
  - High-risk smokers and former smokers 55-74 years of age with ≥30 pack-year smoking history and no history of lung cancer (1 pack-year is equal to smoking one pack per day for 1 year)
  - Former smokers who have quit within the past 15 years
- Minor variations in age (starting at 50 years and extending to 80 years), influence of comorbidities, and stopping rules based on specific society guidelines; refer to table below for summary

Screening Recommendations for Lung Cancer
	Recommendation	Age (Years)	Smoking History	Methodology	Additional Information
American College of Chest Physicians (ACCP) (2013)	Annual screening for high-risk individuals based on results of the NLST^a	55-74	≥30 pack-yr smoking history and current smoker, or smoking cessation within the past 15 yrs	LDCT	Screening offered only in clinical settings similar to those in the trial
ASCO (2014)	Annual screening for high-risk individuals based on results of the NLST^a	55-74	≥30 pack-yr smoking history and current smoker, or smoking cessation within the past 15 yrs	LDCT	Screening offered only in clinical settings similar to those in the trial
American Thoracic Society (ATS)(2015)	Annual screening for high-risk individuals based on results of the NLST^a	55-80	≥30 pack-yr smoking history and current smoker, or smoking cessation within the past 15 yrs	LDCT	Screening offered only in clinical settings similar to those in the trial
NCCN (Lung Cancer Screening guideline, 2018)	Annual screening for high-risk individuals	55-74	≥30 pack-yr smoking history and if former smoker, smoking cessation within the past 15 yrs	LDCT	Screening not recommended for Moderate-risk individuals – ≥50 years with ≥20 pack per year smoking history or secondhand smoke exposure but no additional risk factors or Low-risk individuals – <50 yrs or <20 pack-yr smoking history
NCCN (Lung Cancer Screening guideline, 2018)	Annual screening for high-risk individuals	≥50	≥20 pack-yr smoking history and additional risk factors (other than secondhand smoke) that increase risk to ≥1.3%	LDCT
U.S. Preventive Services Task Force (USPSTF) (2014)	Annual screening for high-risk individuals	55-80	≥30 pack-yr smoking history and current smoker, or smoking cessation within the past 15 yrs	LDCT	Screening can be discontinued once an individual has not smoked for 15 yrs or develops a health problem that limits life expectancy or the ability to have curative surgery
American Association for Thoracic Surgery (AATS) (2012)	Annual screening in current and former smokers	55-79	30 pack-yr smoking history	LDCT
		50-79	20 pack-yr smoking history with additional comorbid conditions that produce a cumulative risk for cancer of at least 5% over the next 5 yrs
		55-79	Long-term cancer survivors
American Cancer Society (ACS)(2013)	Annual screening in high-risk individuals with relatively good health who meet NLST^a criteria	55-74	≥30 pack-yr smoking history and current smoker, or smoking cessation within the past 15 yrs	LDCT	Recommends against the use of chest radiography Strongly suggests individuals enter an organized screening program that has experience in LDCT
NLST included high-risk smokers and former smokers 55-74 years with ≥30 pack-yr smoking history and no history of lung cancer (former smokers must have quit within the past 15 years) LDCT, low-dose computed tomography, NLST, National Lung Screening Trial

Monitoring

Recommended monitoring (postcurative approach)
- CT scanning at prescribed intervals determined by initial staging is recommended
SCLC
- Serial NSE testing may be useful for monitoring tumor recurrence in SCLC
NSCLC
- CK 19 – potential role for monitoring therapy in advanced NSCLC

Background

Epidemiology

Incidence – 55.8/100,000 in the U.S. (National Cancer Institute [NCI], Surveillance, Epidemiology, and End Results [SEER], 2015)
- Leading cause of cancer deaths in the U.S.
Age – peak incidence is 65-74 years; median is 71 years
Sex – M>F, minimal
- Female prevalence has increased; male prevalence has stabilized
Ethnicity – highest incidence in African American males

Risk Factors

Tobacco use – 85-90% of all lung cancers attributed to tobacco use
- 13-fold increase in risk for primary user
- Secondhand smoke exposure – 20-30% increased risk for those who live/have lived with smokers
Radon exposure – likely main cause of lung cancer in nonsmokers
Asbestos exposure – cumulative risk; estimated to cause 3-4% of cases
- Risk increased if patient also smokes
Occupational exposure to carcinogens (eg, bis(chloromethyl)ether, polycyclic aromatic hydrocarbons, chromium, nickel, organic arsenic)
Previous chest irradiation
Genetic – positive family history combined with tobacco use increases the risk

Pathophysiology

Any tumor arising from respiratory epithelium or pneumocytes
Two main types
- NSCLC – ~85% of all lung cancers
  - Adenocarcinoma (nonsquamous cell) – most common
    - Occurs in glandular tissue of lung lining
  - Squamous (epidermoid) cell carcinoma
  - Large cell (large cell anaplastic), other types
- SCLC – ~15% of all lung cancers
  - Epithelial tumor of small cells
    - 95% arise in lung; may also arise from extrapulmonary sites (eg, nasopharynx, gastrointestinal tract, genitourinary tract)
  - Nearly all cases result from smoking
  - Two subtypes
    - Small cell carcinoma (oat cell)
    - Combined small cell carcinoma
Other tumors (rare)
Undifferentiated bronchial-gland tumors, sarcomas, neuroendocrine tumors

Clinical Presentation

20% of cases incidentally identified by chest x-ray for other reasons (patients are typically asymptomatic)
Symptoms based on area of tumor growth
- Central lesion – cough, wheeze, hemoptysis, stridor, dyspnea, postobstructive pneumonia
- Peripheral lesion – pleural/chest wall pain, cough, dyspnea
- Invasion and obstruction of adjacent structures
  - Tracheal obstruction – dyspnea, wheezing
  - Esophageal compression – dysphagia
  - Recurrent laryngeal nerve invasion – hoarseness
  - Phrenic nerve invasion – diaphragmatic paralysis
  - Sympathetic nerve invasion – Horner syndrome
    - Ptosis
    - Miosis
    - Enophthalmos
    - Unilateral loss of sweating
  - Invasion of lung apex – Pancoast tumor, superior vena caval syndrome
- Distant metastasis
  - Superior vena caval syndrome
  - Pericardial tamponade
  - Pleural effusions
  - Pathologic bone fractures
  - Adrenal insufficiency (rare)
- Paraneoplastic syndromes – common; may be first presenting symptoms of lung cancer (SCLC in particular)
  - Endocrine syndromes
    - Ectopic parathyroid hormone
      - Usually squamous cell
      - Hypercalcemia, hypophosphatemia
    - Antidiuretic hormone (ADH)
      - Usually SCLC
      - Syndrome of inappropriate secretion of ADH
      - Hyponatremia
    - Adrenocorticotropic hormone (ACTH)
      - Usually SCLC
      - Usually not Cushingoid in appearance
      - Hypokalemia
  - Skeletal/connective tissue syndromes
    - Clubbing
      - 30% incidence
      - Usually NSCLC
    - Hypertrophic pulmonary osteoarthropathy
      - Usually adenocarcinoma
  - Neurologic/myopathic syndromes
    - Eaton-Lambert syndrome
      - Usually SCLC
      - Myasthenia gravis symptoms
    - Retinal blindness
      - Usually SCLC
    - Peripheral neuropathy
    - Subacute cerebellar degeneration
    - Cortical degeneration
    - Polymyositis
  - Hematologic syndromes
    - Migratory thrombophlebitis – Trousseau sign
    - Nonbacterial endocarditis – marantic endocarditis
    - Disseminated intravascular coagulation
  - Dermatologic syndromes
    - Uncommon
    - Dermatomyositis
    - Acanthosis nigricans
  - Systemic syndromes
    - Unknown etiology
    - Cachexia, anorexia, fever, weight loss, suppressed immunity

ARUP Lab Tests

Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Lung Cancer Panel 2008894
Method: Polymerase Chain Reaction/Pyrosequencing/Immunohistochemistry

Recommended Use

Determine eligibility for TKI therapy

Screening panel detects EGFR mutations (pyrosequencing), and ALK and ROS1 translocations (IHC)

Refer to Additional Technical Information document for further content

Limitations

Results must be interpreted in the context of clinical findings and morphological and other relevant data

Results may be compromised if the recommended tissue fixation procedures are not followed

Lung Cancer Panel with KRAS 2008895
Method: Polymerase Chain Reaction/Pyrosequencing/Immunohistochemistry

Recommended Use

Screening panel to determine eligibility for TKI therapy

Screening panel detects KRAS and EGFR mutations (pyrosequencing), and ALK and ROS1 translocations (IHC)

Refer to Additional Technical Information document for further content

Limitations

Results must be interpreted in the context of clinical findings and morphological and other relevant data

Results may be compromised if the recommended tissue fixation procedures are not followed

Solid Tumor Mutation Panel by Next Generation Sequencing 2007991
Method: Massively Parallel Sequencing

Recommended Use

Assess for targeted variants that are useful for prognosis and/or treatment of individuals with solid tumor cancers, including melanoma, gastrointestinal stromal tumor (GIST), colorectal, bladder, and hepatocellular carcinomas, at initial diagnosis or in the presence of refractory disease

If the clinical indication is lung cancer, additional molecular genetic testing may be considered for detection of gene rearrangements and/or c-MET exon 14-skipping alterations

For evaluation of microsatellite instability, additional molecular testing should be considered

Genes included – AKT1, ALK, APC, ATM, BRAF, CDH1, CDKN2A, CTNNB1, DDR2, EGFR, ERBB2, ERBB4, EZH2, FBXW7, FGFR1, FGFR2, FGFR3, GNA11, GNAQ, GNAS, HRAS, IDH1, IDH2, KDR, KIT, KRAS, MAP2K1, MET, MTOR, NOTCH1, NRAS, NTRK1, PDGFRA, PIK3CA, PTEN, RB1, RET, ROS1, SMAD4, SMO, STK11, TERT promoter, TP53, VHL

Refer to Additional Technical Information document for further content and test limitations

MET Gene Amplification by FISH 2013082
Method: Fluorescence in situ Hybridization

Recommended Use

Determine eligibility for TKI therapy

Aid in prognostication and therapeutic decisions for neoplasms in which amplification has been demonstrated

Screening test for MET gene amplification

Limitations

Results must be interpreted in the context of clinical findings and morphological and other relevant data

Results may be compromised if the recommended tissue fixation procedures are not followed

c-MET by Immunohistochemistry 2008652
Method: Immunohistochemistry

Recommended Use

Determine eligibility for TKI therapy

Detect overexpression of c-MET protein

EGFR T790M Mutation Detection in Circulating Tumor DNA by Digital Droplet PCR 2012868
Method: Polymerase Chain Reaction

Recommended Use

Detect and quantify circulating EGFR T790M point mutation from blood plasma or cerebrospinal fluid (CSF)

Monitor blood plasma or CSF for

Development of EGFR T790M drug-resistant mutation in patients administered TKI therapy for EGFR-mutant NSCLC
Response to therapy and disease progression in patients receiving EGFR T790M-specific TKIs

Limitations

Limit of detection ranges from 0.5% to <0.02% mutant alleles, based upon amplifiable DNA

Optimal clinical testing intervals are unknown

Mutations other than EGFR T790M are not detected

Presence or absence of EGFR T790M does not guarantee a response to EGFR T790M-specific drug therapy

PD-L1 22C3 IHC for NSCLC by Immunohistochemistry with Interpretation, pembrolizumab (KEYTRUDA) 2013284
Method: Immunohistochemistry

Recommended Use

Aid in prediction of response to pembrolizumab (KEYTRUDA) as first- or second-line therapy for patients with NSCLC

Can be performed in conjunction with or instead of PD-L1 28-8 test

FDA-approved test

PD-L1 28-8 pharmDx by Immunohistochemistry with Interpretation, nivolumab (OPDIVO) 2013684
Method: Immunohistochemistry

Recommended Use

Aid in prediction of response to nivolumab (OPDIVO) for patients with nonsquamous NSCLC

Can be performed in conjunction with or instead of PD-L1 22C3 test

FDA-approved test

KRAS Mutation Detection 0040248
Method: Polymerase Chain Reaction/Pyrosequencing

Recommended Use

Determine eligibility for TKI therapy

Predict response to anti-EGFR and MAPK pathway therapies in a variety of malignancies, including lung cancer

EGFR Mutation Detection by Pyrosequencing 2002440
Method: Polymerase Chain Reaction/Pyrosequencing

Recommended Use

Predicts response to TKI therapy

Detect mutations in EGFR exons 18, 19, 20, and 21

ALK (D5F3) by Immunohistochemistry with Reflex to ALK Gene Rearrangements by FISH 2011431
Method: Immunohistochemistry/Fluorescence in situ Hybridization

Recommended Use

Determine eligibility for TKI therapy

Detect ALK fusion proteins (IHC) and ALK gene rearrangements (FISH) in solid tumors

Reflex pattern – ALK (D5F3) by IHC will reflex to FISH if result is equivocal or positive

ALK (D5F3) with Interpretation by Immunohistochemistry 2007324
Method: Immunohistochemistry

Recommended Use

Determine eligibility for TKI therapy

Detect ALK fusion proteins

ALK Gene Rearrangements by FISH, Lung 2006102
Method: Fluorescence in situ Hybridization

Recommended Use

Determine eligibility for TKI therapy

Screening test for all ALK fusions; does not identify the translocation partner or variant

Use this test if companion diagnostic test for crizotinib is required

ROS1 with Interpretation by Immunohistochemistry with Reflex to FISH if Equivocal or Positive 2008414
Method: Immunohistochemistry

Recommended Use

Determine eligibility for TKI therapy

Detect ROS1 fusion proteins (IHC) and ROS1 gene rearrangements (FISH) in solid tumors

Reflex pattern – if ROS1 by IHC is equivocal, then ROS1 by FISH will be added

ROS1 by FISH 2008418
Method: Fluorescence in situ Hybridization

Recommended Use

Determine eligibility for TKI therapy

Detect ROS1 gene rearrangements in solid tumors

Limitations

Does not identify the translocation partner or variant

RET Gene Rearrangements by FISH 2012654
Method: Fluorescence in situ Hybridization

Recommended Use

Determine eligibility for TKI therapy

Detect RET gene rearrangements in solid tumors

Limitations

Does not identify the translocation partner or variant

CYFRA 21-1 (Cytokeratin 19 Fragment), Serum 0081344
Method: Quantitative Enzyme-Linked Immunosorbent Assay

Recommended Use

Use for prognostication and monitoring in NSCLC

Limitations

Do not use for lung cancer screening

Results obtained with different methods or kits cannot be used interchangeably

Test interference – hemolyzed specimens, icteric specimens, lipemic specimens, interfering antibodies in specimen (human antimouse or heterophile antibodies)

CYFRA 21-1 may be elevated in benign respiratory disease and other cancers (eg, urologic, gastrointestinal, gynecological)

Neuron Specific Enolase 0098198
Method: Quantitative Enzyme-Linked Immunosorbent Assay

Recommended Use

Use as a tumor marker for evaluation of neuroendocrine tumors

Limitations

Results obtained with different methods or kits cannot be used interchangeably

Cytokeratin 7 (CK 7) by Immunohistochemistry 2003854
Method: Immunohistochemistry

Recommended Use

Aid in histologic diagnosis of lung cancer