Currently, the diagnosis of lung cancer is very unsatisfactory, and most patients are already in the middle to late stages when they receive the diagnosis. The few cases with early diagnosis are often found during health checkups. The reason for this situation is that many early-stage lung cancer patients are often asymptomatic and do not feel it themselves. In addition, there are quite a number of patients who do not pay attention to the symptoms when they appear, which delays the diagnosis.
I. Symptoms caused by local growth of lung cancer
In the early stage, due to the small extent of lesions, there may be no discomfort. In the middle and late stage, lung cancer often presents cough, hemoptysis, dyspnea, wasting, etc.
1.Cough
Cough is caused by the lesion stimulating the bronchial epithelium and is often an irritating dry cough. Cough is more prominent in squamous lung cancer and small cell lung cancer, because both are mostly central lung cancer. Many patients often do not pay attention to their cough because they smoke or have previous diseases such as bronchitis, and do not go to the clinic, or refuse to have an X-ray chest film or CT scan when they visit the clinic. Among the cases I have seen, many patients who have been coughing for half a year before coming to the clinic have reached an advanced stage.
2.Hemoptysis
Hemoptysis in lung cancer patients is often caused by the rupture of capillaries on the surface of the lesion, mostly a small amount of hemoptysis or blood in sputum. Except for advanced stage of lung cancer where large amount of hemoptysis can occur, large amount of hemoptysis is mostly caused by bronchial dilatation or pulmonary tuberculosis. However, many patients do not pay attention to blood in sputum, thinking that it is just a minor problem and do not pay attention to it.
3.Difficulty in breathing
Dyspnea is caused by lung cancer invading bronchial tubes, forming bronchial stenosis and obstruction, resulting in pulmonary atelectasis, or the mass is so huge that it affects the respiratory function of lung. At this stage, most of them have already entered advanced stage. Dyspnea also appears earlier in squamous lung cancer and small cell lung cancer, while lung adenocarcinoma is mostly peripheral lung cancer, and dyspnea appears relatively later.
4.Loss of weight
Some lung cancer patients have other symptoms such as cough and hemoptysis that are not prominent. If unexplained wasting occurs, they should also be alert to the possibility of lung cancer and should seek medical consultation in time.
Symptoms of lung cancer metastasis
The metastasis of lung cancer is early for small cell lung cancer and lung adenocarcinoma, while the metastasis of lung squamous cancer is relatively late. The most common sites of lung metastasis are lymph nodes, brain, liver, adrenal gland and bone metastasis. Lymph node metastases are earliest in the lungs and mediastinum, while supraclavicular and cervical lymphatic metastases appear as masses in the corresponding areas. Headache may appear in brain metastases. Bone metastasis can cause bone pain.
C. Paraneoplastic syndrome
Paraneoplastic syndrome refers to non-specific local or systemic clinical manifestations other than symptoms caused by direct tumor compression and infiltration and metastasis, which is also known as associated cancer syndrome. Paraneoplastic syndrome associated with lung cancer refers to the extra-pulmonary manifestations caused by the effects of lung cancer on other systems, including abnormal changes in endocrine, neuromuscular, connective tissue, hematological system and blood vessels.
These systemic manifestations may precede the symptoms caused by lung cancer itself and vary with the evolution of the primary site. Because they can be produced before lung cancer is exposed, paraneoplastic syndrome can be a clue for early diagnosis and help to improve the cure rate.
1.Pulmonary hypertrophic osteoarthropathy
Pulmonary hypertrophic osteoarthropathy is often seen in patients with lung squamous carcinoma and is caused by excessive secretion of growth hormone by lung cancer cells. The clinical manifestation is painful joint swelling and pestle-like fingers (toes), which can be relieved after lung cancer disease control. Joint symptoms are more obvious in the large joints of the limbs, mostly invading the distal ends of the long bones of the upper and lower limbs, such as the knee, wrist and ankle, which can be easily misdiagnosed as osteoarthritis such as frozen shoulder.
Patients often have osteoarthrosis with joint swelling and pain, but usually no joint deformity. After resection of lung cancer or lung cancer foci recede or shrink significantly through chemotherapy or radiotherapy, the symptoms of joint swelling and pain can be reduced or disappeared, but after tumor recurrence, joint swelling and pain can appear again or worsen.
2.Neuromuscular syndrome
Neuromuscular syndrome is more common with cerebellar cortical degeneration, peripheral neuropathy and myasthenia gravis. This disease is mostly seen in small cell lung cancer, and can easily appear in non-small cell lung cancer. The specific cause of the disease is unknown, and is not related to the presence or absence of metastasis of the tumor. Patients with predominantly muscular lesions develop muscle weakness, especially the muscles near the pelvis are more severe, and the face often has symmetrical butterfly-shaped erythema. Patients with mainly cerebellar degeneration show movement disorders, nystagmus, dementia, mental changes, etc.
3.Gynecomastia
Gynecomastia is often associated with pulmonary hypertrophic osteoarthropathy. It is caused by excessive secretion of gonadotropins from lung cancer cells. It is often delayed due to lack of attention or shyness of patients, and needs to be differentiated from common breast enlargement. It is mostly seen in large cell undifferentiated carcinoma and small cell lung cancer. Abnormal breast development can coexist with hypertrophic osteoarthropathy and is often seen in the breast ipsilateral to the lung cancer lesion.
4.Cushing syndrome
Some lung cancer cells can secrete adrenocorticotropic hormone-like substances, causing fat deposition and clinical manifestations such as “full moon face”, “buffalo back”, purple lines, swelling, hypertension and increased urine sugar, which are indistinguishable from primary Cushing’s syndrome. If not alerted, it may be misdiagnosed as endocrine system disease.
5. Disturbance of water-electrolyte balance
Patients are often seen for intractable electrolyte disorders, mainly dilutional hyponatremia and hypercalcemia. The former is caused by the secretion of antidiuretic hormone by lung cancer cells, and the latter is caused by the secretion of parathyroid hormone by lung cancer. The symptoms include poor appetite, nausea, vomiting, weakness, drowsiness, thirst, polyuria and mental disorder, etc. Those with this as the first symptom are often misdiagnosed as digestive system diseases.
6.Carcinoid syndrome
Carcinoid syndrome is commonly seen in lung adenocarcinoma or small cell lung cancer, which is caused by excessive secretion of 5-hydroxytryptamine from lung cancer cells. It is characterized by asthma-like dyspnea, paroxysmal tachycardia, watery diarrhea and skin flushing, etc.
7.Honer’s syndrome
It is caused by carcinoma of the apical lung or the upper lung sulcus, with no sweating on the affected side of the head and face, weakness of the upper eyelid in a drooping state and sunken eyes.
8.Echinococcosis nigricans
Mostly seen in lung adenocarcinoma. It is characterized by skin thickening and pigmentation in the axillae or limbs, and the palms of hands, soles of feet and even oral mucosa can also be involved.
9.Pigmentation of skin
Unlike acanthosis nigricans, it is common in exposed parts of the body, such as nipples, lips, cheek mucosa and vulva.