Non small cell lung cancer (NSCLC) accounts for the vast majority of lung cancer cases and includes adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Research over the last two decades has transformed NSCLC from a single disease into a collection of distinct molecular subtypes with different treatments and outcomes.

A major focus is on driver gene alterations such as EGFR, ALK, ROS1, BRAF, MET, RET, KRAS, and HER2. Targeted therapies that inhibit these altered proteins can shrink tumors, prolong survival, and often have different side effect profiles than traditional chemotherapy. For example, EGFR tyrosine kinase inhibitors and ALK inhibitors have become standard options when those mutations or rearrangements are present. Resistance to targeted therapy is common, so newer generations of inhibitors and combination strategies are under active study.

Immunotherapy is another key advance. Drugs that block PD 1 or PD L1 help the immune system recognize and attack cancer cells. They can be used alone or with chemotherapy, especially in advanced disease. Biomarkers such as PD L1 expression and tumor mutational burden are being studied to predict who benefits most.

Research is also refining screening and early detection with low dose CT scans, improving surgical and radiotherapy techniques, and exploring perioperative treatments such as adjuvant and neoadjuvant targeted or immune therapies. Liquid biopsies using circulating tumor DNA aim to track tumor evolution and resistance more quickly and less invasively.

Overall, NSCLC research is moving toward highly personalized care, where molecular and immune profiles guide therapy choices and sequencing over the course of the disease.