What types of cancer is erlotinib suitable for? Does it work against all cancers?

Erlotinib is a tyrosine kinase inhibitor mainly used to treat EGFR (epidermal growth factor receptor) mutation-positive non-small cell lung cancer (NSCLC). Non-small cell lung cancer is the most common type of lung cancer, and EGFR gene mutations are closely related to the occurrence and development of the disease. Erlotinib inhibits the kinase activity of EGFR and blocks the signaling pathways for tumor cell growth, thereby slowing the growth of tumors and prolonging the survival of patients. Erlotinib has become an important treatment option for patients with EGFR mutation-positive tumors.

In addition to non-small cell lung cancer, erlotinib is also approved to treat pancreatic cancer, especially those with advanced, unresectable pancreatic cancer. The treatment options for pancreatic cancer are relatively limited. Erlotinib, as a targeted therapy, has a certain effect on these patients. By targeting EGFR, erlotinib can reduce the proliferation and spread of tumor cells, thereby improving patients' survival rate and quality of life.

However, erlotinib is not effective against all cancers. Its effect mainly depends on the mutation or overexpression of EGFR. Therefore, the efficacy of erlotinib is poor in cancer types where EGFR is not mutated or overexpressed. Therefore, before using erlotinib, patients need to undergo genetic testing to ensure that their cancer cells express or mutate the EGFR gene. Erlotinib may have limited therapeutic benefit in patients who do not have this genetic signature.
In addition, although erlotinib is effective in EGFR-mutated non-small cell lung cancer and pancreatic cancer, not all patients with EGFR mutations will respond well to the drug. As treatment progresses, some patients may develop drug resistance, and may need to switch to other treatment options, such as second- or third-generation EGFR tyrosine kinase inhibitors, or in combination with other types of treatment. Therefore, it is necessary to regularly monitor the efficacy and adjust the treatment plan during the treatment process.
Reference: https://en.wikipedia.org/wiki/Erlotinib