Lung sarcoma. What is the difference between cancer and sarcoma?

There are three main signs of cancerous tumors: growth, penetration into surrounding tissues and metastasis to distant areas of the body. The same characteristics can be attributed to sarcomas. However, they are usually called malignant neoplasms, but not cancer.

Cancer arises from the epithelial cells that line most of the cavities and spaces of the human body. At the same time, sarcomas are formed from mesenchymal cells. In the human body, these cells form fat, cartilage, connective tissue, muscle, bone tissue, as well as blood, lymphatic vessels and nerve sheaths.

Distinctive characteristics of sarcomas:

• do not have a real capsule, but, as a result of prolonged pressure of the tumor on surrounding structures, they can form a pseudocapsule;
• tumor cells are able to spread far beyond the edges of the tumor (along the muscle fibers, fascial plates, vessels, perineural clefts);
• soft tissue sarcomas are primarily prone to hematogenous (through the blood) metastasis (up to 80% to the lungs), and to a lesser extent to lymphogenous (through the lymph);
• the main clinical symptom of sarcoma is the presence of a tumor, and in two thirds of patients, it may be the only one.

Primary lung sarcomas are a group of nonepithelial malignant tumors developing from mesenchymal lung tissue. They are very rare, accounting for only 1.1% of all malignant lung diseases.

Causes and signs of lung sarcoma

Some of the factors that may play a role in the development of lung sarcomas are the following:

• Genetic mutations. Inherited genetic changes may increase the risk of developing pulmonary sarcoma.
• Previous radiation therapy. Radiation to the chest, especially during childhood, may be associated with an increased likelihood of tumor development.
• Impact of environmental factors. Long-term exposure to certain chemicals or carcinogens, such as asbestos or mercury.

Some researchers believe that chronic bronchitis also plays a role in the development of lung sarcomas.

Lung sarcoma: symptoms

The danger of malignant tumors lies in the fact that at an early stage they do not manifest themselves in any way. As the tumor progresses, patients experience symptoms such as:

• cough with sputum production;
• chest pain;
• dyspnea;
• increased body temperature;
• hemoptysis.

On average, it takes 6 months from the appearance of the first symptoms of sarcoma to diagnosis and initiation of treatment. There were cases when this period was 4-6 years.

Classification and types of lung sarcoma

Pulmonary sarcomas are primary and secondary. Primary tumors form directly in the lungs. Secondary sarcomas are metastases that have spread to the lungs from tumors that have arisen in other parts of the body.

Depending on the type of tissue from which tumors arise, doctors distinguish the following types of sarcomas:

• Myogenic – affects muscle tissue (leiomyosarcoma, rhabdomyosarcoma).
• Angiogenic – effect vessels in the lungs (hemangiopericytoma, hemangioendothelioma, low-grade angiosarcoma).
• Neurogenic – affects nervous tissue.
• Malignant non-Hodgkin’s lymphomas (lymphosarcoma, plasmacytoma).
• Malignant fibrous histiocytomas.
• Carcinosarcoma.
• Others (fibro-, chondro-, liposarcoma, malignant paraganglioma).
• Unclassified sarcomas.

Myogenic and angiogenic sarcomas are the most common.

Where and how quickly does sarcoma metastasize?

The rate at which pulmonary sarcomas metastasize varies greatly depending on the histological type of tumor and individual factors. Most neoplasms of this type are highly aggressive – they quickly penetrate the surrounding tissues and spread to distant areas of the body. Most often, lung sarcomas metastasize to the pleura, brain, liver and adrenal glands.

Metastases in the lungs due to sarcoma

As mentioned above, lung sarcoma can be primary or secondary. Secondary lesions develop due to the spread of a tumor localized in another part of the body. Sarcomas are quite aggressive tumors. Most often they metastasize to the lungs:

• soft tissue sarcomas – in 20% of cases;
• bone tissue sarcomas – in 40% of cases.

In 19% of patients, the lungs are the only metastatic site. Sarcomas of any subtype have the potential to metastasize to the lungs, but osteosarcomas, synovial tumors, and liposarcoma are most prone to this.

The development of pulmonary metastases negatively affects prognosis: without treatment, most patients die within 6–11 months after diagnosis. Chemotherapy remains the standard approach in the treatment of sarcomas. However, if it is used alone, survival rates improve only slightly. At the same time, surgery can significantly prolong the life of patients.

Stages of lung sarcoma

• Stage I – a tumor node measuring up to 3 cm in diameter or a tumor of the segmental bronchus, without regional metastases.
• Stage II – a tumor node from 3.1 to 6 cm in diameter that does not invade the visceral pleura, or a tumor that has not spread beyond the lobar bronchus, without or with single regional metastases.
• Stage III – a tumor more than 6 cm in diameter, growing into the visceral pleura or spreading to the main bronchus, with metastases in regional lymph nodes.
• Stage IV – the tumor occupies a lobe or the entire lung, or a neoplasm of any size with characteristic pleurisy and metastases in distant organs. Lung sarcoma of the fourth stage also includes a multinodular form of the disease.

Diagnosis of lung sarcoma

Diagnosing primary pulmonary sarcomas is a rather difficult process, since they are very rare. Lung carcinomas are detected 700 times more often. Symptoms of the disease are nonspecific and the main task of doctors is to distinguish the primary tumor from the metastatic one, since sarcomas of bones and soft tissues often metastasize to the lungs.

One of the main diagnostic methods is x-ray examination. Next, oncologists prescribe a puncture biopsy and histological analysis of sputum. Additionally, CT, MRI and PET-CT may be prescribed to assess the extent of tumor spread.

Since lung sarcoma is a rare disease, its diagnosis and treatment should be carried out by a doctor who has previously encountered it. Leave a request in the form below, and the MedTour coordinating doctor will select for you an oncologist specializing in the treatment of sarcomas.

The latest methods for diagnosing cancer

More recently, scientists have discovered that malignant tumors have molecular differences, even if they are localized in one part of the body. These differences have made it possible to create drugs that specifically target tumor cells. Targeted drug molecules recognize specific mutations on the surface of pathological cells and specifically attack them. Since normal cells do not carry these specific mutations, healthy tissue is not affected by targeted therapy.

To find out whether targeted therapy will be effective in a particular patient, it is necessary to create a molecular portrait of the tumor and find out whether there are target proteins on the surface of its cells. Similar tests are carried out in the best diagnostic centers in the world. Leave a request in the form below, and the MedTour coordinating doctor will select for you a clinic or laboratory that performs molecular genetic research in the field of oncology.

Is it possible to cure lung sarcoma without surgery?

A retrospective analysis of the Surveillance, Epidemiology and End Results database showed that the 5-year survival rate of patients with primary lung sarcoma was:

• 41% after surgery;
• 25% after surgery and adjuvant (postoperative) radiation therapy;
• 7% for those who received radiation therapy only.

Thus, surgical treatment allows to achieve the best result. However, this study involved standard radiation therapy. In recent years, lung sarcoma has begun to be treated using stereotactic radiosurgery (CyberKnife technology).

CyberKnife in the treatment of lung sarcoma

The main reason for poor tumor control with conventional radiation therapy is insufficient total radiation dose. CyberKnife delivers a much higher biologically effective dose compared to standard radiotherapy. In addition to this direct effect of killing tumor cells, CyberKnife destroys the vascular bed of the tumor, causing it to shrink in size.

For early-stage non-small cell lung cancer, stereotactic radiosurgery is the standard option for patients who are medically inoperable or who refuse surgery. For primary lung sarcomas, CyberKnife began to be used relatively recently. But there is already evidence that at an early stage, targeted radiation can destroy the tumor without surgery.

Leave a request in the feedback form below. The MedTour coordinator will select a doctor for you who will be able to determine whether treatment with stereotactic radiosurgery will be effective in your particular case.

Surgery for lung sarcoma

In most cases, pulmonary sarcoma can be treated with organ-preserving surgery: lobectomy, economical lung resection. The need for total pneumonectomy is primarily due to damage to the main bronchus or the gigantic size of the tumor. If the malignant process spreads to adjacent structures, an extended or combined pneumonectomy is performed.

Paresis of the larynx after surgery to treat lung cancer

Because of their anatomical location around the aortic arch, the left vagus nerve and recurrent laryngeal nerve are frequently affected by hilar malignancies. For the same reason, these nerves may be cut during lung tumor resection or mediastinal lymph node dissection. Nerve damage causes dysfunction of the left vocal cord, which in turn leads to varying degrees of glottis insufficiency and swallowing problems. During resection of lung cancer, vocal cord paralysis occurs in approximately 10% of patients.

Currently, there are progressive methods for treating laryngeal paresis and restoring voice. Virtus Medical Center has been using injection laryngoplasty and augmentation rhinoplasty since 2015. The SmartCell biotechnological laboratory, which operates at the center, has developed an innovative method for producing a graft from a patient’s adipose tissue. At the same time, platelet-rich plasma is injected into the vocal cords.

The essence of the technique is to augment (build up) a paralyzed ligament in order to restore the normal function of the ligamentous apparatus. The effectiveness of the method is very high. More than 90% of patients report an improvement in their voice after the procedure. Leave a request in the feedback form below to learn more about the innovative method of treating laryngeal paresis.

Lung sarcoma – prognosis (how long do people live with lung sarcoma)

Primary pulmonary sarcoma is a very aggressive malignancy. It has a significantly worse median 5-year survival rate (35%) than soft tissue sarcomas of the extremities (71%).

In the surgical treatment of patients with pulmonary sarcoma, the size of the primary lesion, histological structure, the condition of the intrathoracic lymph nodes and the degree of tumor differentiation play a role. The best 5-year survival rates can be achieved with:

• malignant non-Hodgkin’s lymphoma (85.7%);
• angiogenic sarcoma (66.7%);
• malignant fibrous histiocytoma (62.5%).

With myogenic sarcoma of the lungs, the prognosis is unfavorable and amounts to 33.3%.

The best clinics for the treatment of lung sarcoma

MedTour company cooperates with the best clinics around the world. Currently, we can offer lung cancer treatment in Turkey, Germany, Spain, Italy, South Korea and other countries where the field of oncology is well developed. Leave a request in the feedback form below to receive a free consultation. The MedTour coordinator will select for you the best oncology center specializing in the treatment of sarcomas, and will also help resolve all organizational issues.

The best doctors for the treatment of lung sarcoma

Lung sarcoma is very rarely diagnosed, so it is important to find a doctor who has experience treating this disease. Leave a request in the form below to receive a free consultation. The MedTour coordinator will select an oncologist who specializes in the treatment of lung cancer and sarcoma in particular.

Published: 08.01.2024

Updated: 10.04.2024

Medical author, Medical editor:

Olena Kursabaieva

Medical author, Medical editor:

Natalia Segen