Many types of cancer cells originating in the lungs have been identified and considered highly preventable. The two major types are Small-Cell Lung Cancer and Non-Small Cell Lung Cancer. Small cell lung cancer account for 10-15%of the lung cancer cases and are named after the tiny size of the cancer cells.
Approximately, 80-90% of the lung cancers are reported to be of Non-Small Cell type, which is again classified into subtypes based on the place of origin and characteristics of the cancer cells. A common sub-type is the Adenocarcinoma, accounting for 40% of the lung cancers, while large cell carcinoma is an aggressive type that makes the early detection and treatment much more difficult.
Lung cancers are considered to be highly preventable as 85%-90% of the cases are the effects of long term smoking. Advancements in the medical field make it easier for people to let go of their addiction to nicotine. Exposure to asbestos, industrial smoke, chemicals, and second-hand smoke can be avoided with precautionary steps.
Lung cancer is a killer disease estimated to cause 159,480 deaths in America this year. The cancerous cells causing this deadly disease damage the lung tissues hindering the normal functioning of the lungs to the cells lining the bronchioles, which are the tiny tubes acting as air passages.
Lung Cancer Stages
Diagnosing the type of lung cancer and its current progression plays a very critical role in designing a suitable treatment strategy. Non-Small Cell Lung Cancer progresses through six stages.
Occult or the hidden stage is where the cancer cells are found in certain body fluids and can be detected in the sputum because cancer cells do not show up in the imaging tests.
Stage 0 or Carcinoma in situ, cancer cells could be detected only in the innermost lining of the lungs, and tumor formation would not have started yet. Stage I mark the growth of a malignant tumor and progress in two stages. In stage IA, the tumor is said to measure less than 3 cm and stay without spreading to surrounding tissues, while in stage IB, the tumor would have grown into main bronchus and pleura.
At Stage II, the tumor reaches the size of 5 to 7 cm. The cancer cells may affect the lymph nodes or other parts of the lung like the diaphragm and the chest wall.
At stage III, the cancer cells’ advances further to the lymph nodes which may cause the affected lung to collapse due to inflammation and metastasis to surrounding organs like the heart membrane, major blood vessels, trachea, esophagus, chest bone, back bone and even the nervous system.
Stage IV is the most advanced stage and incurable stage. The tumor may be of any size, and the cancer cells are found in the fluids surrounding the lungs and heart. The tumor may metastasize to other organs in the body leading to cancer metastasis.
Small-cell lung cancer detection and stages
Progression of the disease in small-cell lung cancer is divided into Limited Stage, where the cancer cells affect only one lung and the lymph nodes on that side, and the Extensive Stage, where the tumor spreads to both the lungs, lymph nodes and other body organs.
A lung cancer that is detected during the early stages has a 70% chance of complete cure, and the treatment would require only a surgery to remove the tumor, while lung cancer at stage III is said to have 25% chance of cure.
Hence, people who are in the high-risk group with excessive exposure to polluted air, and smoking is advised to undergo a low-dose spiral CT scan, which has been proven to an effective screening technique, decreasing the risk of death due to lung cancer. A CT scan may cost between $300 and $500.
Research has shown that surgery proved to be the choice of treatment for stage I and stage II. On the other hand, small cell lung cancer is shown to respond more efficiently to chemotherapy and radiation therapy, even when diagnosed at limited stage.
A chemotherapy before a radiation therapy or surgery has been recommended as the drugs shrink the tumor, making its removal easier. However, chemotherapy has the biggest disadvantage of side effects as the drugs do not differentiate between healthy and malignant cells.
Targeted therapy, the emerging trend in lung cancer treatment is known to act on the tumor cells to stop the further growth of the tumor. Some of the commonly used drugs in the targeted therapy include Erlotinib (Tarceva), Bevacizumab (Avastin), Crizotinib (Xalkori).
A study published earlier this month suggested that the tumor growth in non small cell lung cancer can be suppressed by inactivating a gene responsible for the survival and progression of the malignant cells.
Researchers are exploring various options including gene therapy to increase the survival rate among lung cancer patients, which at present has a very low five-year survival rate of only 30-50% in the early cancer stages.
With the advancement in the medical industry, lung cancer cells could be easily identified and highly preventable if high-risk individuals take the initiative to get the screening for lung cancer.
Written by: Janet Grace Ortigas