What is Lung Cancer?
Lung cancer begins in the cells of the lungs. It develops when normal cell division and growth are disrupted, leading to uncontrolled, abnormal growth of cells which become a mass or tumor. Cigarette smoking is the most common risk factor for lung cancer.
Lung cancer symptoms aren’t always present in the early stages of the disease, meaning lung cancer is often diagnosed when the disease is at a more advanced stage. This means the disease is more complex and difficult to treat. Identifying lung cancer early is very important.
Learn more about lung cancer symptoms, causes and risk factors here.
Diagnosing lung cancer
Lung cancer often presents with subtle symptoms in its early stages, making early detection vital for successful treatment.
Usually, concern that a patient may have lung cancer starts when an abnormal finding is seen on a chest imaging study (chest X-ray or CT scan) or when the disease is advanced enough to cause symptoms, such as coughing, shortness of breath, chest pain, fatigue and/or weight loss.
How lung cancer is diagnosed is different from person to person. Imaging tests, supported by several minimally invasive procedures, may be required if the imaging results reveal a possible cancer.
Traditionally, lung cancer diagnosis requires a biopsy, or the removal of cells or tissues from the suspicious mass. Biopsies can be performed through a camera fed through the breathing tubes (called bronchoscopy) or from a needle inserted through the skin into the lung tumor. If these approaches are not successful, surgery may be required for an adequate diagnosis. The biopsy is important in determining whether or not it is cancer, and to determine which type of lung cancer is present.
Innovations in diagnosing lung cancer
Innovations such as low dose computed tomography (LDCT) scans have improved the early detection process, allowing doctors to identify lung cancer at its earliest and most treatable stages in some patients. These non-invasive screening techniques have proven highly effective in high-risk individuals, leading to better outcomes and increased survival rates.
Diagnostic tests include:
Imaging tests
- Low dose computed tomography (CT) scan: The procedure works like a regular CT scan, but at a much lower radiation dose, decreasing the risk associated with frequent examinations. Producing cross sectional images, it creates detailed 3D images of the lungs.
- Positron emission tomography (PET) scan.
Procedures
- Bronchoscopy: A procedure in which a hollow flexible tube, or bronchoscope, is used to visually examine inside the patient’s lungs and collect samples for laboratory testing including electromagnetic guided navigation to lung lesions.
- Endobronchial ultrasound (EBUS): A bronchoscope (a thin, lighted, flexible tube) is used to take ultrasound images of the lungs and airways using soundwaves that make pictures. This is done with local anesthesia and sedation.
- Mediastinoscopy and mediastinotomy: Both procedures allow a surgeon to look and take samples of the lymph nodes in the area between the lungs.
- Transthoracic CT guided biopsy: A method of obtaining an image-guided a biopsy of the pulmonary lesion.
- Thoracoscopy: A procedure in which a camera is inserted through an incision in the chest to view the lungs and surrounding area.
These important tests and procedures can help determine whether cancer is present, help tell how advanced the disease is and provide information that will help specialized teams to identify and treat lung cancers at the earliest possible stage, maximizing chances of recovery and survival.
Staging lung cancer
Staging is the next step in lung cancer diagnosis process and allows the doctor to fully understand the extent of the patient's cancer to help make treatment decisions and determine expected outcomes. Doctors use specific terms to describe the stages of cancer, but a straightforward way of describing staging might be as follows:
- Localized: The cancer is confined to the lung.
- Regional: The cancer has spread to lymph nodes (or glands) within the chest. Lymph nodes act as a filtering system outside the lung, collecting cancer cells that are beginning to migrate out of the lung.
- Distant: The cancer has spread (or metastasized) to other parts of the body.
Treating lung cancer
All relevant information about the patient, including their health status, the kind of tumor and how far it has spread are brought together to design the most appropriate treatment plan for that individual's cancer.
Lung cancer is a very challenging cancer to treat. The most critical factor in determining the survival rate is the stage at the time of diagnosis. Those that are diagnosed at a localized stage are often curable. Unfortunately, most people are diagnosed when the disease has spread outside the chest (advanced or distant) or involves the nodes in the chest (regional).
It is important to discuss the goals of lung cancer treatment with your doctor. While some treatments aim to cure lung cancer, others may be used to control the cancer and improve quality of life and/or reduce symptoms. These treatments may be used alone or in combination.
Surgery
Surgery is still considered the 'gold standard' for treating early-stage lung cancer.
Removing the tumor and surrounding lung tissue gives the best chance for cure for patients whose disease is localized. Surgery should be performed by specialized thoracic surgeons with particular expertise in the treatment of lung cancer and other chest malignancies. Your surgeon will determine whether a tumor is resectable (removable). Not all tumors are resectable due to their location near or if they have invaded vital structures.
In some patients with multiple medical problems or poor lung function, surgery may not be the best option. This is carefully determined by our multidisciplinary team including pulmonologists, medical oncologists and radiation oncologists who work collaboratively daily.
Types of surgery
How much lung tissue will be removed and what type of surgical approach will be used depends on where the tumor is located in the lung, its size, patient's body type/weight and any previous chest surgeries. All patients are considered first for minimally invasive surgery, although some complex cases may still require a traditional, open approach. Trained thoracic surgeons perform video-assisted thoracic surgery (VATS) and VATS lobectomy routinely as well as robotic surgery. Surgical resection of lung cancer is generally performed as:
- Limited resection: An operation to remove only a small portion of the lung is called a segmental or wedge resection
- Lobectomy: Removal of large section of the lung, (there are three lobes of the lung on the right and two on the left), is called a lobectomy. This is the most common surgery performed for lung cancer
- Pneumonectomy: The removal of an entire lung is called a pneumonectomy.
Recovery after thoracic surgery depends on the extent of the surgery, whether or not it is performed minimally invasively as well as the age and overall fitness of the patient. Many patients return home within three to four days after surgery. Patients who undergo minimally invasive surgery can generally return to work three weeks after surgery.
Minimally invasive approaches
Where possible, treatment is performed using minimally invasive techniques or approaches called Robotic-Assisted Thoracoscopic Surgery and Video-Assisted Thoracic Surgery (VATS).
- Robotic-assisted thoracoscopic surgery
This procedure involves the use of a high precision 3D camera and robotic surgical system. The surgeon controls robotic surgical instruments that are inserted through small incisions in the chest. The surgeon uses a 3D camera system to view the surgical site with enhanced depth perception and magnification. Robotic arms mimic the surgeons’ hand movements with more precision and stability, making this an ideal approach for complex surgeries.
- Video-assisted thoracic surgery (VATS)
VATS, also a minimally invasive approach, is a technique with similar small incisions made in the chest wall, and a tiny camera called a thoracoscope is inserted through one of the incisions. This allows the surgeons to see inside the chest cavity and perform the surgery using specialized instruments that are inserted through the other small incisions. The surgeon is then able to remove a portion of the lung, repair damaged tissue or biopsy suspicious areas.
Advanced, minimally invasive treatment approaches in lung cancer have revolutionized patient care, providing viable alternatives to traditional open surgeries. While these techniques offer numerous benefits, their suitability depends on factors such as tumor stage, size, location, and individual patient characteristics.
Chemotherapy
Chemotherapy is the use of drugs that are designed to kill rapidly growing cells, such as cancer cells. Chemotherapy may be injected directly into a vein or can be taken as a pill.
In early stages of non-small cell cancer, chemotherapy may be used in conjunction with surgery to improve survival rates. In more advanced stages of non-small cell cancer and in all stages of small cell cancer, chemotherapy, immunotherapy and targeted therapies may be used to treat lung.
Chemotherapy affects both normal cells and cancer cells. Your doctors will try to prevent side effects as much as possible while treating the cancer appropriately. Side effects depend largely on the specific type of drug and the amount given. They can be different for each person and may be only temporary. Common side effects of chemotherapy include nausea and vomiting, hair loss, mouth sores and fatigue. Your doctor can suggest ways to make any side effects more manageable and to help relieve symptoms that may occur during and after procedures.
Personalized medicine and precision oncology
Advances in genetic profiling and molecular diagnostics have paved the way for personalized medicine in lung cancer treatment. Precision oncology allows doctors to identify the unique genetic makeup of each patient's tumor, enabling the selection of targeted therapies most likely to be effective. This approach maximizes treatment benefits while minimizing side effects. Through ongoing research and technological advancements, the field of personalized medicine continues to evolve, offering hope for improved outcomes and quality of life for individuals diagnosed with lung cancer.
- Molecular profiling
Molecular profiling involves analyzing the genetic makeup and molecular alterations of a patient's tumor cells. This process helps identify specific genetic mutations, alterations, or biomarkers that drive the growth and progression of the cancer. Techniques such as next-generation sequencing (NGS) enable comprehensive genomic profiling, providing a detailed understanding of the tumor's genetic make-up. Molecular profiling helps guide treatment decisions, identify potential targets for therapy, and predict a patient's response to specific treatments.
- Targeted therapies
Targeted therapies are medications designed to selectively inhibit specific molecules or pathways involved in the growth and survival of cancer cells. They differ from conventional chemotherapy, which broadly targets rapidly dividing cells. Targeted therapies are most effective when specific genetic alterations or biomarkers are identified in a patient's tumor.
- Immunotherapy
Immunotherapy harnesses the body's immune system to recognize and attack cancer cells. Immune checkpoint inhibitors block certain proteins (like PD-1 or PD-L1) that suppress the immune response, allowing immune cells to recognize and destroy cancer cells. Immunotherapy has shown remarkable success in lung cancer treatment, particularly in patients with advanced or metastatic disease, and it has significantly improved overall survival rates. Recent studies have shown that they are also very effective in earlier stages and can be used to reduce tumor size before surgery.
- Resistance mechanisms and combination therapies
Resistance to targeted therapies can develop over time. Cancer cells may acquire additional mutations or bypass mechanisms that render the treatment less effective. Researchers are studying mechanisms of resistance to develop strategies to overcome them. Additionally, combination therapies that target multiple pathways simultaneously or combine targeted therapy with immunotherapy are being explored to enhance treatment efficacy and overcome resistance.
Precision medicine and targeted therapies have revolutionized lung cancer treatment by tailoring interventions to each patient's specific molecular profile. They have resulted in improved treatment outcomes, prolonged survival rates, and enhanced quality of life for many lung cancer patients. Ongoing research and advancements in molecular profiling techniques will further refine and expand the range of targeted therapies available, improving personalized treatment approaches for lung cancer patients.
Radiation Therapy
Radiation therapy is a form of high energy X-ray that kills cancer cells. It can be used as a primary treatment, or in combination with chemotherapy (with or without surgery). It is the main treatment of locally advanced disease and can also be used in patients with very advanced tumors to relief pain, blockage of the airways, bleeding, shortness of breath or coughing.
Radiation therapy is a focused treatment, meaning it is designed to maximize its effect on the cancer cells while minimizing any injury to normal cells. Radiation to treat lung cancer most often comes from a machine (external radiation). Occasionally, the radiation may be delivered internally using transfer tubes to bring a radioactive seed directly into or near the tumor (internal radiation or brachytherapy).
Side effects of radiation therapy depend mainly on the part of the body that is treated and the treatment dose. Common side effects of radiation therapy to the chest include a sore throat, difficulty swallowing, fatigue, and decrease in appetite. Skin changes are very uncommon.
An area of particular innovation in radiation therapy is a high-technology approach, termed stereotactic radiosurgery or stereotactic radiotherapy. In very select patients who have small tumors but for whom surgery is unsafe, particularly in the brain, radiosurgery using very high doses of precisely focused radiation aimed only at the small tumor in the lung, is a very effective alternative without the need to undergo surgery.
- Stereotactic body radiation therapy (SBRT): Is commonly used for early-stage lung tumors. This modern radiation technique delivers high-dose radiation precisely to the tumor while minimizing exposure to surrounding healthy tissues. This technique uses advanced imaging techniques and respiratory management to precisely map the tumor's location and deliver highly focused radiation beams from multiple angles. SBRT is often used for early-stage lung cancer or for patients who are not candidates for surgery due to various reasons. It typically involves a shorter treatment course compared to conventional radiation therapy, with fewer side effects and excellent tumor control rates.
Radiofrequency ablation and microwave ablation
Microwave ablation uses microwaves and radiofrequency ablation uses radio waves to heat cancerous cells to destroy them.
- Microwave ablation (MWA): A minimally invasive technique that uses high frequency electromagnetic waves to generate heat and destroy tumor cells, enabling faster and more efficient heating of the tumor tissue. MWA is particularly advantageous for larger tumors or lesions that may be less responsive to RFA. This procedure can be performed percutaneously (through the skin) or during minimally invasive surgery, offering an alternative treatment option for selected patients.
- Radiofrequency ablation (RFA) A localized treatment option for small lung tumors or lesions that are difficult to reach surgically. A needle-like probe is inserted through the skin and positioned into the tumor under image guidance. The probe emits high-frequency electrical currents, generating heat that destroys the cancerous cells. RFA is a minimally invasive alternative to surgery and can be performed on an outpatient basis. It is especially beneficial for patients with early-stage lung cancer or those who are not suitable candidates for surgery due to various reasons.
Lung Cancer Screening
Lung cancer screening refers to testing a healthy individual at high risk for developing lung cancer who has no symptoms of lung cancer in hopes of finding lung cancer at a stage that it can be cured. Low-dose chest CT based screening has been found to reduce the number of people who die from lung cancer with acceptable risks when performed in a high-quality setting.
At Cleveland Clinic Abu Dhabi, we have a comprehensive lung cancer screening program for those individuals at high risk of developing lung cancer. Learn more.
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