In early stages, signs and symptoms of lung cancer are not always present or easily identifiable. Hence many lung cancers are diagnosed in later stages.
Signs and symptoms which may be present in a person with lung cancer include:
No symptoms: According to studies, about 25% of people with lung cancer may not have any symptoms. It may be discovered through a routine chest X-ray or CT scan as a small round mass (also known as coin lesion—as on two-dimensional X-ray or CT scan, the round tumour looks like a coin).
Symptoms related to the cancer: As the cancer grows and invades lung tissues and surrounding tissues, it may cause symptoms such as:
If a nerve is invaded by cancerous cells, it may cause symptoms such as shoulder pain that travels to the outside of the arm (called Pancoast's syndrome), or paralysis of the vocal cords causing hoarseness of voice. If oesophagus is invaded, it may lead to difficulty swallowing (dysphagia). Obstruction of large airway by the tumour can cause collapse of a portion of the lung, or infections (abscesses, pneumonia) in the obstructed part.
Symptoms related to metastasis: Lung cancer can spread to the bones, brain or other parts of the body. If bone is involved, it may cause pain at the sites of bone involvement. Spread of cancer to brain may cause a number of neurologic symptoms such as headaches, seizures, or symptoms of stroke (such as weakness of a part of body or loss of sensation in certain areas).
Paraneoplastic symptoms: Some lung cancers may secrete hormone-like substances. The body reacts to these substances and it causes some specific symptoms known as paraneoplastic syndromes. These syndromes are most common in SCLC but may occur in any type of lung cancer. Some common paraneoplastic syndromes associated with lung cancer include overproduction of a hormone called adrenocorticotrophi c hormone (ACTH) by the cancer cells, leading to oversecretion of the hormone cortisol by the adrenal glands. This causes Cushing's syndrome or secretion of a chemical similar to parathyroid hormone. This further results in elevated levels of calcium in the bloodstream.
Nonspecific symptoms: Nonspecific symptoms which may occur in a person with lung cancer include weight loss, weakness, and fatigue. Some people may experience psychological symptoms such as depression and mood changes.