Key Differences in a Lung Cancer Biopsy & Pathology Report

1. Biopsy Methods for Lung Cancer

Since the lungs are located deep inside the chest, biopsies for lung cancer are performed using specialized techniques, such as:

• Bronchoscopy biopsy – A thin tube with a camera is inserted into the lungs through the mouth or nose to collect tissue samples.
• Needle biopsy (CT-guided or transthoracic biopsy) – A thin needle is inserted through the chest wall to sample lung tissue.
• Endobronchial ultrasound (EBUS) biopsy – A special type of bronchoscopy that uses ultrasound to guide the biopsy.
• Surgical biopsy – If needed, doctors may perform a thoracoscopy or thoracotomy to remove a larger sample.

2. Common Types of Lung Cancer in the Report

Your pathology report will specify the type of lung cancer found, which is crucial for treatment decisions. The two main types include:

• Non-Small Cell Lung Cancer (NSCLC) (about 85% of lung cancers)
  • Adenocarcinoma – The most common type, often found in non-smokers and peripheral lung areas.
  • Squamous Cell Carcinoma – Linked to smoking and typically found in the central airways.
  • Large Cell Carcinoma – A less common, aggressive form of NSCLC.
• Small Cell Lung Cancer (SCLC) (about 15% of lung cancers)
  • A more aggressive type that spreads quickly and is often diagnosed at an advanced stage.

3. Staging Information for Lung Cancer

Lung cancer staging helps determine the best treatment plan. The pathology report will indicate:

• Tumor size (T stage) – How large the tumor is.
• Lymph node involvement (N stage) – Whether the cancer has spread to nearby lymph nodes.
• Metastasis (M stage) – Whether the cancer has spread to other parts of the body.

4. Molecular and Genetic Testing for Targeted Therapy

Lung cancer pathology reports often include biomarker testing to check for genetic mutations and protein expressions. These results determine if targeted therapies or immunotherapies are options. Some key biomarkers include:

• EGFR mutations – Targeted by drugs like osimertinib (Tagrisso).
• ALK or ROS1 rearrangements – Treated with specific inhibitors like alectinib or crizotinib.
• PD-L1 expression – Determines if immunotherapy (e.g., pembrolizumab) is an option.
• KRAS mutations – Guides the use of new targeted drugs.

5. Presence of Necrosis or Spread to Lymph Nodes

• The report may describe necrosis, which indicates how aggressive the tumor is.
• Lymph node involvement suggests whether cancer has begun spreading, affecting treatment options.

6. Liquid Biopsy Option

In some cases, a liquid biopsy (blood test) may be performed to detect circulating tumor DNA (ctDNA), especially if a traditional biopsy is not possible. This test helps guide treatment decisions without needing invasive procedures.