Dr. Karthik Chandra VallaM
(MBBS, M.S, M.Ch, D.N.B Surgical Oncology)
What is Lung cancer?
Lung cancer is a form of cancer that starts in the lungs, usually from the cells that line the airways. It's a widespread type of cancer worldwide and a major contributor to cancer-related fatalities. There are two primary kinds of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
Types of lung cancer:
There are 2 main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
Non-Small Cell Lung Cancer (NSCLC):
Non-small cell lung cancer (NSCLC) stands as the predominant form of lung cancer, representing more than 80% of diagnosed cases. Predominant subtypes within NSCLC include adenocarcinoma and squamous cell carcinoma, with adenosquamous carcinoma and sarcomatoid carcinoma being rarer variants.
Lung adenocarcinoma begins in the lung cells that produce mucus, known as epithelial cells. These cells cover the lung's surface. It is the most prevalent form of non-small cell lung cancer. Lung adenocarcinoma primarily affects individuals who smoke or have a history of smoking. However, it is also the most frequent type of lung cancer found in non-smokers. It is more common in women and tends to occur in younger individuals compared to other lung cancer types.
Squamous cell carcinoma:
Originating from flat cells lining the airways within the lungs, squamous cell carcinoma is frequently associated with a history of smoking and tends to localize in the central regions of the lungs, close to the main airway (bronchus).
Large cell (undifferentiated) carcinoma:
Large cell carcinoma, capable of arising in any lung region, poses treatment challenges due to its rapid growth and widespread dissemination. The subtype, large cell neuroendocrine carcinoma (LCNEC), progresses swiftly and closely resembles small cell lung cancer.
There are a couple of other types of NSCLC, like adenosquamous carcinoma and sarcomatoid carcinoma, that are not as frequently seen.
Small cell lung cancer (SCLC)
SCLC makes up around 10% to 15% of all lung cancers.
SCLC usually has a faster growth rate and spreads quicker than NSCLC. It often spreads beyond the lungs by the time it is diagnosed. Because of its rapid growth, it tends to respond well to chemotherapy and radiation therapy. Unfortunately, in most cases, the cancer is likely to come back.
Other types of lung tumors
Along with the main types of lung cancer, other tumors can occur in the lungs.
Lung carcinoid tumors:
Less than 5% of lung tumors are accounted for by carcinoid tumors, with the majority exhibiting slow growth.
Other lung tumors:
There are some rare forms of lung cancer, like adenoid cystic carcinomas, lymphomas, and sarcomas, as well as benign lung tumors called hamartomas. These types of lung cancer are treated differently from the more common ones.
Cancers that spread to the lungs:
Sometimes, cancers from different organs like the breast, pancreas, kidney, or skin can spread to the lungs, but these are not lung cancers.
- Smoking: The primary cause of lung cancer; both active and passive smoking increases the risk.
- Exposure to carcinogens: Occupational exposure to asbestos, radon, and certain chemicals.
- Family history: A genetic predisposition may contribute to the risk.
- Persistent cough.
- Chest pain.
- Shortness of breath.
- Unexplained weight loss.
- Coughing up blood.
Imaging tests: X-rays, CT scans, and PET scans.
Biopsy: Removal of a small tissue sample for laboratory examination.
- Surgery: Removal of the tumor or affected lung tissue.
- Radiation therapy: Using high doses of radiation to target and kill cancer cells.
- Chemotherapy: Medications to kill cancer cells or stop their growth.
- Targeted therapy: Drugs targeting specific molecules involved in cancer growth.
- Immunotherapy: Boosting the body's immune system to fight cancer cells.
- Quitting smoking is the most effective preventive measure.
- Avoid exposure to secondhand smoke and occupational carcinogens.
- Talking to your doctor is important for maintaining health when dealing with factors like a family history of lung cancer. Non-smokers with lung cancer may undergo targeted therapy for specific DNA mutations, such as those in the EGFR gene.
Getting regular screenings is really important for people who are at high risk, like heavy smokers. It can help catch any problems early on and improve the chances of a positive outcome. Being aware of lung cancer and taking action early is key to fighting against this disease.
What are Mediastinal tumors?
Mediastinal tumors are abnormal growths that form in the mediastinum, which is the middle part of the chest between the lungs. This crucial area houses important structures like the heart, thymus, lymph nodes, and other vital components. Different kinds of tumors that can develop in the mediastinum, such as thymomas, lymphomas, germ cell tumors, and cysts. These tumors can either be harmless (noncancerous) or harmful (cancerous).
Common Types of Mediastinal Tumors:
- Thymomas: Arise from the thymus gland and can be either benign or malignant.
- Lymphomas: Cancer originating from lymphocytes, a type of white blood cell.
- Germ Cell Tumors: Develop from reproductive cells and can occur in the mediastinum.
- Cysts: Fluid-filled sacs that may be congenital or acquired.
- Thyroid Tumors: Thyroid disorders can lead to abnormal growth of thyroid tissue in the mediastinum.
- Malignant Tumors: In some cases, tumors may be secondary (metastatic) and spread to the mediastinum from other parts of the body.
Almost 50% of new mediastinal tumor cases show no symptoms at all. These tumors remain undetected until a chest X-ray is required. Symptoms may arise depending on the tumor's size and position, causing pressure on the spinal cord, heart, or pericardium. These symptoms can include:
- Coughing, with or without blood, along with shortness of breath and hoarseness.
- Experiencing wheezing or a high-pitched sound during breathing.
- Night sweats, chills, or fever.
- Unexpected weight loss and anemia, along with swollen or tender lymph nodes.
Causes and Risk Factors
Mediastinal tumors are not very common. The location of the tumors usually varies based on the patient's age. Tumors found in the front part of the mediastinum are more likely to occur in individuals between the ages of 30 and 50. On the other hand, children with mediastinal tumors often have benign ones.
To confirm a diagnosis of a mediastinal tumor, your doctor may prescribe tests, including:
- Imaging studies, including X-rays, CT scans, and MRI, help visualize the tumor.
- A biopsy involves taking a small tissue sample for laboratory analysis to determine if the tumor is benign or malignant.
What is the treatment for a mediastinal mass?
The treatment for mediastinal tumors depends on the kind of tumor, where it is, how much it has spread (if it's cancer), and the symptoms you have. Surgery is usually the main way to treat them.
- Radiation therapy
Preventing mediastinal masses is not possible, but early detection can increase the likelihood of successful treatment. If you experience symptoms like shortness of breath or persistent coughing for more than two weeks, it's advisable to consult a healthcare provider.
Various tumors can form in your mediastinum. Some are serious and require immediate treatment. With others, you may not experience symptoms or need treatment at all. Your healthcare provider can explain your tumor type and whether it’s serious. Ask your healthcare provider about likely outcomes based on the type of tumor you have.