What are the early symptoms of lung cancer?

Most lung cancer patients have advanced disease by the time they see their doctor. And early stage lung cancer has a chance to be cured. How can early lung cancer be detected?

Why is lung cancer difficult to detect early?

Patients with early-stage lung cancer may not have any symptoms. This is mainly because the alveoli do not have sensory nerves and cannot feel pain. The lungs are relatively large, and early lung cancer lesions are usually small, so they rarely cause significant symptoms. Most of the associated symptoms appear due to the increased size of the tumor, which involves the bronchi and pleura. Even when symptoms appear, they are ignored because most of them are atypical, such as cough and chest pain.

What do you mean by “atypical” symptoms? For example, “egg-shaped stools” are usually typical for fall diarrhea (rotavirus infection), while “full-moon face, buffalo back” are typical. full-moon face and buffalo back” suggest Cushing’s syndrome (excessive glucocorticoids). Unfortunately, lung cancer does not have such “exclusive” symptoms.

On the other hand, screening is the most effective means of detecting early lung cancer, and is currently recommended internationally by low-dose spiral CT, which is not widely available due to the cost, equipment, and expertise of the test.

What are the early symptoms of lung cancer?

The common early symptoms of lung cancer are summarized below. Knowing these will help us to be alert and seek timely medical attention:

Symptoms	Clinical manifestations and causes of occurrence
Chronic cough	This is the most common symptom of lung cancer, usually an irritating dry cough, sometimes accompanied by coughing sputum; Chronic cough is caused by lung cancer invading the trachea and bronchi; Although nearly half of all lung cancer patients have chronic cough at diagnosis, not all patients with chronic cough have lung cancer.
Coughing up blood	This is one of the common symptoms in patients with lung cancer and is the only symptom in 7% of patients in clinical practice. It can manifest as blood in the sputum or bloody sputum, and once more severe coughing up of blood occurs, it indicates disease progression and critical condition. As a result of tumor cells invading the bronchial mucosa. The tumor is surrounded by abundant blood vessels, and when the capillaries or small blood vessels rupture, it will lead to coughing up blood.
Chest Pain	There are close to half of patients who present with early chest pain. It is worse with deep breathing, coughing, and laughing. The pain is often dull or vague, diffuse, and often not clearly localized, sometimes not consistent with the tumor site. The viscera are insensitive to pain and sensitive to pulling. Therefore, it is often when the tumor invades the pleura and chest wall that persistent chest pain occurs. When the tumor causes pleural effusion, it also causes chest pain.
Short of breath	Often manifests as shortness of breath after exercise, inspiratory dyspnea, chest tightness, etc; Caused by tumor compression of the airway, or obstruction resulting in pneumonia, pulmonary atelectasis (reduced volume or air content of lung segments or lobes), malignant pleural effusion, diffuse alveolar lesions, etc; Sometimes shortness of breath is often mistakenly thought to be due to aging or weight gain.
Recurrent infections	Presenting with fever, cough, sometimes coughing yellow pus sputum; Tumor compression or obstruction of the bronchial tubes, causing obstructive pneumonia due to obstructed drainage of the distal lung; at the same time, patients with lung cancer have decreased immunity and are prone to accompanying infections.
Shoulder or arm pain	This is a common presentation of supraglottic sulcus (Pancoast tumors); In addition to shoulder pain and medial upper arm pain, this pain can radiate toward the little finger. Sometimes it can also manifest as hand weakness and tingling, and Horner’s syndrome – droopy eyelids, no sweating on one side of the face, and flushing and sweating on one side of the face. Suprapulmonary sulcus tumors located at the narrow thoracic inlet tend to invade nerves, blood vessels, and their adjacent ribs and vertebrae, causing these symptoms.
Unexplained weight loss	Generally defined as a weight loss of more than 5% over a period of 6 to 12 months. A subset of lung cancer patients clinically present with weight loss before diagnosis. It is sometimes overlooked because there is no significant discomfort.

Other symptoms that may occur include:

1. Fatigue and lethargy: a generalized feeling that is difficult to relieve with good rest;
2. Heartiness: tumors or enlarged lymph nodes in the mediastinum that compress or invade the recurrent laryngeal nerve can paralyze the vocal cords and cause hoarseness, a symptom that is often difficult to take seriously;
3. Swelling of the face, neck, and arms: This may also be accompanied by dilated veins in the neck and chest, a manifestation of superior vena cava syndrome (SVC syndrome), a complication of lung cancer;
4. Shortness of breath: When the tumor obstructs the airway, it can cause shortness of breath;
5. Thrombotic symptoms: manifesting as leg pain, swelling, and life-threatening pulmonary embolism if the thrombus occurs in the lung;
6. Paraneoplastic Syndromes: manifesting as pestle and mortar fingers, painful enlarged joints in the extremities, myasthenia gravis, hypercalcemia, and carcinoid syndrome.

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What should I do if I develop these symptoms?

Some studies have found that people who smoke are more likely to ignore early symptoms of lung cancer. However, lung cancer is not the only disease that smokers need to worry about. In recent years, the incidence of lung cancer in young, non-smoking women has been on the rise, so if you experience one or more of these symptoms, you need to get checked out at the earliest possible time.

It’s worth noting that lung cancer sometimes has no symptoms in its early stages, and many people find lung nodules by chance during a health checkup, only to find out it’s lung cancer on further examination. Therefore, lung cancer screening is very important.

Co-reviewed by: Guangdong Provincial People’s Hospital Guangdong Lung Cancer Institute Dr. Wang Zhen, Deputy Chief Physician Dr. Xue Tao Lai