What is Sarcomatoid cancer?
Sarcomatoid cancer (SARC) of the lung is a rare type of Non-Small Cell Lung Cancer (NSCLC). Non-Small Cell lung cancer accounts for about 80% of all lung cancers. There are several types of Non-Small Cell lung cancer and each type is associated with a uniquely different type of cancer cells. Sarcomatoid cancer cells tend to invade the lung tissue more deeply than other types of cancerous cells.
It has been suggested that radiotherapy for the treatment of a patient’s other cancer’s may induce a Sarcomatoid change in lung tissue which could preempt the subsequent development of a Sarcomatoid Carcinoma.
Sarcomatoid cancer (SARC) is sometimes found in other parts of the body although the incidence is more common in the upper body, particularly the lungs. Although this rare form of cancer has been associated with a poor prognosis, its effect on survival rates and incidence of recurrence has not been well documented or studied to date.
The survival rate in patients diagnosed with SARC is dependent upon a number of factors such as any metastases and the original cause or site of the cancer. In a recent study, the five year survival rate for Sarcomatoid cancer patients was 24.5% compared with 46.3% for patients with other forms of NSCLC.
Primary pulmonary Sarcomatoid Carcinoma can only be differentiated from other types of carcinoma by close examination involving immunohistochemistry (microscopic and biologic examinations) and molecular analysis. Once a tumor is identified as being SARC, it is then further defined by the presence of spindle cell lesions in the lung. SARC may also be described as a Carcinosarcoma, a Pseudosarcomatoid Carcinoma or spindle cell Carcinoma. These are all terms which define the lesions as seen on examination.
SARC is an aggressive form of cancer and the resultant tumors are frequently symptomatic, locally advanced and have high rates of recurrence. Non-surgical treatments are usually recommended for patients with clinically advanced Sarcomatoid cancer.
Inflammatory Sarcomatoid Carcinoma is an aggressive tumor with an unusually benign appearance. Inflammatory SARC amounts to just 0.1% to 0.4% of all lung malignancies and most often occurs in male smokers who are usually around 60 years of age at the time of diagnosis.
Patients most often present with cough, hemoptysis (coughing blood), chest pain, and dyspnea (shortness of breath). As with other non-small cell carcinomas of the lung, the clinical stage of SARC seems to be the most important prognostic factor. The diagnosis of Sarcomatoid Carcinoma cancer requires the exclusion of other diseases that histologically – that is, microscopically – may appear similar. It is therefore most often not confirmed as being SARC until tumor sampling has been carried out.
SARC may be mistaken for an inflammatory pseudo-tumor (IP) which is the most common type of lung cancer found predominantly in younger patients who have a history of cigarette smoking. Chest x-rays can’t always distinguish between SARC and IP so again, histologic investigations as well as biopsy may be required to make an accurate diagnosis.
The definitive diagnosis of Sarcomatoid Carcinoma with a primary or metastatic lung sarcoma – especially spindle cell carcinoma – can again be difficult and in-depth studies may be required to establish if the SARC is primary or secondary to other pulmonary cancers. The treatment options for Sarcomatoid Carcinoma will vary depending upon many factors to do with the patients overall condition.