How long does targeted therapy take to work for lung cancer?

Targeted medicines are selected for specific molecular changes in a tumour. The medicine used, the extent and location of disease, overall health and other treatments can all influence when a response becomes visible.

Some people notice changes such as easier breathing, less coughing or improved energy before a scan is available. Others have no immediate symptom change. Symptoms alone cannot confirm whether treatment is working, so your team may use examination, oxygen assessment when needed, blood tests and imaging to build a clearer picture.

Follow the dosing schedule and tell your oncology team about missed doses, new medicines, supplements or breathing changes. Keep a simple record of cough, breathlessness, pain, appetite and activity so trends are easier to discuss.

Attend the review appointments even if you feel well. Ask which scan will be used, when it is expected and what would count as benefit, stable disease or a reason to reconsider the plan. Do not change or stop the medicine without medical guidance.

Call your cancer team promptly for a new or worsening cough, increasing breathlessness, chest pain, coughing blood, high fever, severe diarrhoea, a widespread rash or marked weakness. Seek emergency care for severe breathing difficulty, blue lips, fainting, confusion or sudden chest pain.

What molecular result makes this medicine suitable for me? When will you check my symptoms and scan? Which changes could be a treatment side effect rather than cancer progression? What is the plan if the first assessment is unclear?