Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. As they grow, the abnormal cells can form tumors and impede the function of the lung. Left untreated, lung cancer eventually causes death. Symptoms include a cough that does not go away, chest pain, hoarseness, weight loss, loss of appetite, bloody or rust-colored sputum, shortness of breath, recurring infections such as bronchitis and pneumonia, and wheezing. However, lung cancer usually does not cause severe symptoms until it has spread too far to be cured. Approximately 84 percent of lung cancers are diagnosed in an advanced stage.1
Lung cancer is caused by internal factors inherited from our genes and external or environmental factors like exposure to asbestos, radon, and smoke. Of all internal and external factors, the number one cause is smoking cigarettes. A 2008 World Health Organization (WHO) report noted that in the 20th century, the tobacco epidemic killed 100 million people. During the 21st century, it could kill one billion.2 Both smoking and lung cancer are important health issues worldwide.
Types of Lung Cancer
The two main types of lung cancer are called small cell lung cancer and non-small cell lung cancer. Non-small cell lung cancer is usually treated by surgery. Small cell lung cancer is mainly treated by chemotherapy and radiotherapy. A diagnosis of lung cancer also comes with a stage-I, II, III, or IV. The more advanced the disease, the higher the stage, impacting both prognosis and treatment.
Almost 70 percent of patients with non-small cell lung cancer are diagnosed when they are already at stage III or IV3, which means the cancer has spread and surgery is not an option. Similarly, almost 70 percent of patients with small cell lung cancer aren't diagnosed until the cancer has spread beyond the lung.4 The greatest opportunity to improve survival lies in early detection.1
Methods for Lung Cancer Diagnosis
Current methods for lung cancer diagnosis can be divided into two types: image based methods like x-ray, CT scan, MRI, and PET, and microscopic techniques such as biopsy, sputum cytology, bronchoscopy, and thoracoscopy. Confirmation can only be made with a biopsy, where a tissue sample is removed and studied under a microscope. Unlike other cancers like cervical and prostate cancers, there hasn't been a good technique to screen for lung cancer. In fact, the American Cancer Society notes that because lung cancer often spreads beyond the lungs before it causes symptoms, a good screening test to find lung cancer early could save many lives.1
Biomarkers and Screening
Fortunately, blood tests can now uncover biomarkers that are early indicators for lung cancer. Biomarkers are molecules found in the body that can signal an abnormal process or disease. These developments have made lung cancer prognosis more hopeful including aid in diagnosing between non-small cell lung cancer and small cell lung cancer, estimating disease prognosis and progression, monitoring recurrence after treatment, and vastly improving screening.
Screening programs should aim to find lung cancer at an early stage when there are more options. It has been shown that screening with multiple circulating tumor markers provides improved sensitivity for cancer detection in people not showing symptoms before they reach the fatal, advanced stage.5
Screening could become part of an annual physical for high-risk patients, particularly ones who may have the genes that can cause lung cancer. Two gene variants appear to make some smokers and former smokers more susceptible to lung cancer. These variants exist in about 34 percent of the population.6 After being identified as high risk, there is a blood test that looks for biomarkers correlated to lung cancer. If there is a positive result, an imaging test follows to eliminate false positives or to isolate a tumor.
Benefits of Biomarker Testing
Biomarkers provide patients with peace of mind-letting you know earlier if you have a benign or cancerous tumor. And if lung cancer is present, this kind of testing can help detect the disease earlier. The stage in which lung cancer is diagnosed is critical in planning treatment options. Early detection and therapeutic intervention can greatly improve one's survival and quality of life.
Specific Lung Cancer Biomarker Tests
Testing for lung cancer biomarkers is reliable, accurate, non-invasive, and affordable. Abbott Laboratories recently launched ARCHITECT ProGRP as a marker for small cell lung cancer. This test is used to aid in the differential diagnosis of lung cancer and disease management, both in conjunction with other clinical methods.7 Biomarker testing is a new development in medical technology that is accessible to the average person all over the globe.
Key to Improved Outcomes
It's called the 90/10 survival curve-catch cancer early and there's a 90 percent survival rate but catch it in its later stages and chances of survival are only 10 percent.8 Early detection of lung cancer is the key to improving the outcome of the disease. You may be at risk for lung cancer if you smoke or are often around smoke, if you are 60 years or older and have a history of smoking, have had previous lung tumors, or have chronic obstructive pulmonary disease (COPD). If you are at risk, talk with your doctor about biomarker screening. Even if you have been diagnosed with lung cancer, lifestyle changes and diagnostic testing using biomarkers can help you manage your disease and treatment. The signs are there. And now you know how to find them.
