What are the first symptoms of lung cancer, and when is an investigation warranted?

2026-09-15

In its early stages, lung cancer is often completely asymptomatic or presents with non-specific complaints, which is why a significant proportion of patients are diagnosed only at an advanced stage. The most common initial symptoms include a persistent cough or a change in the character of a chronic cough, dyspnea, chest pain, and haemoptysis. In addition, general systemic symptoms often appear, such as unexplained loss of appetite, weight loss, and chronic fatigue. In rarer cases, due to mediastinal extension or metastases of the tumour, difficulty swallowing (dysphagia) or paraneoplastic neurological syndromes may also be the first observed complaints. An investigation is indicated in all cases where respiratory symptoms (especially a cough persisting for more than 2–3 weeks, shortness of breath, or chest pain) do not resolve, when the character of a cough changes in smokers, or when an isolated episode of haemoptysis and unexplained weight loss occur. Furthermore, in high-risk individuals (particularly those with a significant smoking history), organised or individual screening with low-dose chest computed tomography (LDCT) is recommended even in an asymptomatic state.\n\nBased on data from clinical trials and cohorts, the early detection of lung cancer represents a serious challenge, as in more than 70% of patients the diagnosis is made only after the onset of symptoms, often in an advanced stage. In cases detected via screening (LDCT) or as incidental findings, the proportion of early stages treatable with curative intent is substantially higher, and overall survival is significantly longer.\n\nAccording to structured diagnostic protocols, upon detection of suspicious symptoms, a chest X-ray or low-dose chest CT is indicated as a first-line radiological examination. In the presence of an abnormal imaging finding or high clinical suspicion, a multidisciplinary investigation—including contrast-enhanced CT, tissue sampling, and organ-specific functional tests—must take place within targeted time windows in order to minimise therapeutic delay.

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