Lung cancer

Lung cancer

Lung cancer is the leading cause of cancer mortality in men and second only to breast cancer in women.

Frequency

• • 175,000 new cases per year
  • 70 cases per 100,000 population
  • The predominant age is 50-70 years
  • The predominant gender is male.

Risk factors

• • Smoking. There is a direct relationship between smoking and the incidence of lung cancer. An increase in the number of cigarettes smoked every day leads to an increase in the disease. Passive smoking is also associated with a slight increase in incidence.
  • industrial carcinogens. Exposure to beryllium, radon and asbestos increases the risk of developing lung cancer, and smoking further increases this risk
  • Prior lung disease. It is possible to develop adenocarcinomas in scar areas with tuberculosis or other lung diseases accompanied by fibrosis; such tumors are called cancers in the scar
  • Certain cancers (such as lymphoma, head, neck, and esophageal cancer) lead to an increased incidence of lung cancer. Pathological anatomy.
  • Adenocarcinoma is the most common histological variant of lung cancer. In the group of malignant lung tumors, its share is 30-45%. Smoking addiction is not so obvious. The tumor often affects women. The usual location is the periphery of the lung.
  • Histological examination reveals distinct acinar cell masses emanating from the distal airways.
  • Characteristics – often the formation of adenocarcinoma is associated with scarring in the lungs resulting from chronic inflammation
  • Growth may be slow, but the tumor metastasizes early and spreads via the hematogenous route. In addition, its diffuse distribution in the tissue of the lung along the branches of the tracheobronchial tree is likely.
  • Bronchioloalveolar carcinoma (a variant of adenocarcinoma) originates in the alveoli, spreads along the walls of the alveoli, and causes hardening of the lobe that is easily detected radiographically. Bronchoalveolar cancer is found in three forms: a single node, multinodular and diffuse (pneumonic) forms. The prognosis is relatively favorable.
  • Squamous cell carcinoma is the second most common variant of lung cancer (25-40% of cases). Clearly linked to smoking
  • Histological examination. It is assumed that the tumor arises from squamous metaplasia of the epithelial cells of the tracheobronchial tree.
  • Characteristic. Squamous cell carcinoma is more often detected near the root of the lung in the form of endobronchial lesions (in 60-70% of cases) or peripheral rounded formations
  • The tumor is voluminous, causing bronchial obstruction
  • Characterized by slow growth and late metastases
  • Subject to necrosis of the central areas with the formation of cavities.
  • Small cell carcinoma (oat cell). Tumor with high malignancy. Among malignant lung tumors, its share is within 20%
  • Histological examination reveals nest-like clusters or layers, consisting of small round, oval or spindle-shaped cells with a round dark nucleus.
  • Cells contain secretory cytoplasmic granules
  • The tumor secretes biologically active substances
  • Characteristic
  • The tumor is usually located centrally
  • Characterized by early metastasis by the hematogenous or lymphogenous route
  • After timely excision of stage I small peripheral tumors, complete recovery is likely in the early periods. Unremoved tumor cells in the majority of cases respond to combined chemotherapy
  • The prognosis is bad.
  • Large cell undifferentiated cancer is not often detected (5-10% of all forms of lung cancer)
  • Histological examination reveals large tumor cells without clear signs of differentiation
  • Characteristic
  • Can develop in both central and peripheral areas
  • High degree of malignancy
  • The prognosis is bad.

TNM classification (see also Tumor, staging)

• • T, – the tumor is not more than 3 cm in diameter, there are no signs of invasion
  • T2 Tumor greater than 3 cm in diameter or tumor of any size that invades the visceral pleura or is accompanied by atelectasis, obstructive pneumonia, extending to the root of the lung
  • T3 Tumor of any size that invades adjacent tissues (eg, pleura or chest wall), affects the main bronchus, or tumor with concomitant atelectasis or pneumonia.

Clinical picture

• • Pulmonary symptoms: productive cough with blood in the sputum; obstructive pneumonia (typical for endobronchial tumors); dyspnea; chest pain, pleural effusion, hoarseness (due to compression of the mediastinal tumor of the recurrent laryngeal nerve); fever; hemoptysis; stridor; compression syndrome of the superior vena cava (combination of thoracic vein expansion, cyanosis and swelling of the face with an increase in intracranial pressure; caused by obstruction of the vessel by a mediastinal tumor). The disease may be asymptomatic.
  • Extrapulmonary symptoms
  • Extrapulmonary metastases are accompanied by weight loss, malaise, signs of CNS damage (epileptiform convulsions, signs of meningeal carcinomatosis), bone pain, enlarged liver and pain in the right hypochondrium, hypercalcemia.
  • Paraneoplastic manifestations (extrapulmonary manifestations not associated with metastases) appear secondarily due to the action of hormones and hormone-like substances secreted by the tumor. These include Cushing’s syndrome, hypercalcemia, osteoarthropathy, and gynecomastia. Ectopic ACTH secretion causes hypokalemia and muscle weakness, while inappropriate ADH secretion leads to hyponatremia.
  • Pancoast’s tumor (cancer of the upper lobe of the lung) may cause symptoms due to involvement of the brachial plexus and sympathetic ganglia; probably the destruction of the vertebrae as a result of the germination of the tumor. There are pains and weakness in the arm, its edema, Horner’s syndrome (ptosis, miosis, enophthalmos and anhidrosis associated with damage to the cervical sympathetic trunk).

Laboratory research

• • General blood test – anemia
  • Hypercalcemia.

Special Studies

• • Chest x-ray or CT – infiltrate in the lung tissue, mediastinal enlargement, atelectasis, enlargement of the roots of the lung, pleural effusion. Doubtful changes on the radiograph in patients older than 40 years are highly likely to indicate lung cancer
  • Sputum cytology and bronchoscopy confirm the diagnosis of endobronchial cancer. Bronchoscopy also allows evaluation of proximal extension of the tumor and the status of the contralateral lung.
  • Transthoracic needle biopsy under fluoroscopy or CT guidance is not often necessary for the diagnosis of peripheral cancer.
  • Thoracotomy or mediastinoscopy in 5-10% allows diagnosing small cell lung cancer, more prone to growth in the mediastinum than in the lumen of the bronchi. Mediastinoscopy or mediastinotomy can be used to evaluate the resectability of the hilar and mediastinal lymph nodes.
  • Lymph node biopsy allows examination of suspicious cervical and supraclavicular lymph nodes
  • Scanning of the chest, liver, brain and adrenal glands, mediastinal lymph nodes helps to detect metastases
  • Radioisotope scanning of bones helps to exclude their metastatic lesion.

Treatment:

• • Non-small cell lung cancer.
  • The method of choice is surgical (lung resection), which determines the need to assess the resectability of the tumor and the prevalence of the neoplasm outside the chest cavity. The radicalism of surgical intervention determines the distance of the line of intersection of the bronchus by 1.5-2 cm from the edge of the tumor and the absence of cancer cells, determined in the edge of the crossed bronchus and vessels
  • Lobectomy. Performed with a lesion limited to one lobe
  • Extended resections and pulmonectomy. Performed if the tumor affects the interlobar pleura or is located close to the root of the lung
  • Wedge resections, segmentectomy. Carried out with a localized tumor in patients from a high-risk group.
  • Radiation therapy (in inoperable cases or as an adjunct to surgical treatment)
  • Reduces local recurrence rate in resectable stage II cancers
  • Indicated for patients suffering from heart and lung diseases and unable to undergo surgery. 5-year survival varies between 5-20%
  • Radiation therapy is particularly effective for Pancoast tumors. For other tumors, radiation therapy is traditionally prescribed in the postoperative period for patients with mediastinal metastases.
  • Combined chemotherapy gives a therapeutic effect in approximately 10-30% of patients with metastases of non-small cell lung cancer. A twofold increase in the therapeutic effect is noted in the absence of cachexia in patients receiving outpatient treatment. Chemotherapy for lung cancer in most cases does not help prolong the life of the patient and does not even have a palliative effect. The result does not depend on whether it is used in its pure form or in combination with surgery. Combination chemotherapy is effective only in the treatment of small cell lung cancer, especially when combined with radiation therapy. Preoperative chemotherapy (alone or in combination with radiotherapy)

for the treatment of tumors in stage Ilia, in particular with N2 degree of involvement of the lymph nodes. Frequently used schemes:

• • Cyclophosphamide doxorubicin and cisplatin
  • Vinblastine, cisplatin
  • mitomycin vinblastine and cisplatin
  • Etoposide and cisplatin
  • ifosfamide etoposide and cisplatin
  • Etoposide fluorouracil, cisplatin
  • Cyclophosphamide doxorubicin, methotrexate and procarbazine.
  • Small cell lung cancer. The basis of treatment is chemotherapy. Therapeutic regimens: etoposide and cisplatin or cyclophosphamide, doxorubicin and vincristine.
  • Localized cancer – a tumor within one pleural cavity; neoplasm can be completely cured by irradiation of the root of the lung. The maximum survival rates (10-50%) are noted in patients who received both radiation and chemotherapy, especially combined chemotherapy and fractional irradiation.
  • Disseminated cancer – the presence of distant metastases, involvement of the supraclavicular lymph nodes and / or exudative pleurisy. Such patients are shown combined chemotherapy. In the absence of the effect of chemotherapy or the presence of brain metastases, radiation gives a palliative effect.
  • Contraindications for thoracotomy. In about half of the patients, by the time the diagnosis is established, the disease is so advanced that thoracotomy is inappropriate. Signs of inoperability:
  • significant involvement of the mediastinal lymph nodes from the side of the tumor (N2), especially the upper paratracheal
  • involvement of any contralateral mediastinal lymph nodes (N3)
  • distant metastases
  • pleural effusion
  • superior vena cava syndrome
  • recurrent laryngeal nerve injury
  • phrenic nerve palsy
  • severe respiratory failure (relative contraindication).

Surveillance after surgery

• • First year – after 3 months
  • Second year – after 6 months
  • From 30% of it to the fifth year – 1 r / year. Prevention is the elimination of risk factors. Complications
  • Metastasis
  • Relapse due to incomplete tumor resection.

Forecast

• • Non-small cell lung cancer. Key prognostic factors are tumor extent, objective status scores, and weight loss
  • Survival – 40-50% in stage I and 15-30% in stage II
  • Maximum survival – after extended removal of mediastinal lymph nodes
  • In advanced or inoperable cases, radiation therapy gives a 5-year survival rate in the range of 4-8%.
  • Limited small cell carcinoma. In patients who received combined chemotherapy and radiation, long-term survival rates range from 10 to 50%. In cases of advanced cancer, the prognosis is poor.

Synonym. Epidermoid carcinoma of the lung See also Hypercalcemia in malignant tumors; tumor, radiation therapy; Tumor, markers; Tumor, methods of treatment; Tumor, stages, Paraneoplastic syndrome ICD C34 Malignant neoplasm of bronchi and lung Note. Consider the possibility of prophylaxis with retinoids, for example, B-carotene.

Literature

• • Lung cancer. Davydov MI, Polotsk BE. M.: Radiks, 1994
  • Lung Cancer: A Guide for Physicians. Kharchenko VP, Kuzmin NV M.: Medicine, 1994