Lung Cancer (Bronchial Carcinoma): Test and Diagnosis

Laboratory parameters of 1st order – obligatory laboratory tests.

  • Small blood count
  • Differential blood count
  • Electrolytes – calcium, phosphate
  • Fasting glucose (fasting blood sugar)
  • Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (gamma-GT, GGT), alkaline phosphatase, bilirubin.
  • Renal parameters – urea, creatinine, cystatin C or creatinine clearance, if necessary.
  • Examination from sputum (sputum examination), bronchial lavage (“bronchial lavage”), bronchoscopy, puncture or thoracotomy obtained cells (cytological or genetic studies) or biopsies / tissue samples (histological / fine tissue studies).
  • Histology (fine tissue examination); obtaining biopsy material (tissue sampling) by means of:
    • Bronchoscopy (lung endoscopy) or mediastinoscopy (endoscopic method of examining the space between the two lung lobes, the interstitial space (mediastinum)) – for centrally growing carcinomas.
    • Transbronchial forceps biopsy (TBB)/bronchoscopic peripheral forceps biopsy – for peripheral carcinomas.
    • Transthoracic puncture (CT- or sonography-guided puncture; fine needle biopsy: approximately 6-15% of cases associated with pneumothorax/entry of air into the pleural space) – for peripheral carcinomas.
    • Transbronchial needle aspiration (TBNA) under fluoroscopy for peripheral round lesions is a safe procedure and has a high sensitivity of approximately 90% (percentage of diseased patients in whom the disease is detected by the use of the test, i.e., a positive test result occurs).
    • Percutaneous transthoracic biopsy (PTNB): when atypical cells are detected, the percentage of malignant diagnoses (“malignant finding”) is the highest at more than 90%, and the percentage of nonspecific benignity (“benignity”) is the lowest at approximately 20%
    • Open resection of the focus (as far as this focus is primarily operable; see findings in PET-CT).
  • For classification of lung carcinoma (genotype; ploidy and chromosomal alterations; detection of specific gene mutations/molecular markers).
  • Epidermal groth factor receptor (EGFR) mutations – in non-small cell lung cancer (NSCLC) [if positive → EGFR tyrosine kinase inhibitor (TKI)]
  • Mutation T790M detection – in non-small cell lung cancer (NSCLC) due to resistance to EGFR inhibitors (e.g., afatinib, erlotinib, or gefitinib).
  • Liquid biopsy: circulating tumor DNA fragments (ctDNA) in blood [ASCO 2018].
    • For early stages (stages 1-3A): sensitivity: 38%; specificity: 52%.
    • For late stages (stages 3B and 4): sensitivity: 87-89%; specificity: 98 percent %.
  • If necessary, pollutant analysis (see risk factors: inhalative carcinoge) – if workplace exposures are present.

Laboratory parameters 2nd order – depending on the results of the medical history, physical examination, etc. – for differential diagnostic clarification / follow-up.

  • Tuberculin determination
  • Tumor marker (only suitable for follow-up diagnostics!)
    • Squamous cell carcinoma: Cyfra 21-1, SCC, CEA, ACE.
    • Small cell carcinoma (English : Small Cell Lung Cancer, SCLC): ACE, CEA, NSE, LDH as prognostic parameters.
    • Adeno-Ca: CEA, Cyfra 21-1, ACE.
  • Subtyping of non-small cell lung cancer (NSCLC) from endobronchial biopsies (3-4 samples):
    • EGFR gene mutation (EGFR mutations in exons 18-21, on ALK fusions (ALK = anaplastic lymphoma kinase; persistently activated in 3-5% of patients with non-small cell lung cancer (NSCLC)) and ROS1 fusions, and BRAF V600 mutations ; material: in tumor tissue from non-curable) due toTherapy with a tyrosine kinase inhibitor (TKi, e.g., afatinib, erlotinib, or gefitinib) as first-line therapy.
    • Immunohistochemical examination for expression of the ligand PD-L1 (“programmed cell death-ligand 1”); if positive: monoclonal antibodies against PD-1.
  • If necessary, additionally: ACTH (adrenocorticotropic hormone), 5-HIES (5-hydroxy-indoleacetic acid) in the urine.
  • Tumor follow-up: small blood count, ESR (erythrocyte sedimentation rate), ferritin [an elevated serum ferritin level in elderly patients with advanced primary bronchial carcinoma is associated with poor prognosis(1)], AP (alkaline phosphatase), γ-GT, LDH (lactate dehydrogenase).