Lung cancer is classified into two major types based on the appearance of cancer cells under a microscope. This two major types are : Non-Small cell lung cancer and Small cell lung cancer.
1. Non-Small cell lung cancer (NSCLC) : It is the most common type of lung cancer. accounting for about 80-85% all cases of Lung cancer. It occurs when normal lung cells undergo changes and grow uncontrollably, usually Non-Small cell lung cancer, the cancer cells are larger in size and generally grow slowly as compared to Small cell lung cancer (SCLC).
Non-Small cell lung cancer has 3 major subtypes : Adenocarcinoma, Squamous cell carcinoma, and Large cell carcinoma.
Adenocarcinoma
Adenocarcinoma is the most common subtype of Non-Small cell lung cancer (NSCLC), accounting for about 40% of all lung cancer cases. It begins in the glandular cells of the lungs which secretes substances such as mucus, and usually developed outer region of the lungs, particularly in the alveoli. This type of cancer is more common in women, younger individuals, non smokers and former smokers. It grows slowly as compared to other cancer and spread to the other part of the body if untreated. Symptoms includes like persistent cough, weight loss, chest pain and shortness of breath. There are many treatment options such as surgery, radiation therapy, chemotherapy which depends on stages of the cancer. Early detection may increase survival rates.
Squamous cell carcinoma
Squamous cell carcinoma (SCC) of the lung is also known as epidermoid carcinoma. it is a subtype of Non-Small cell lung cancer, that accounts for about 30% cases of all lung cancers. It usually originates in the flat squamous cells lining the airways, typically in the central part of the lung near the bronchi. these cells usually grow slowly and can spread to the brain, liver, adrenal glands. Smoking is the primary risk factor. Other risk factors for SCC may includes such as age, family history and exposure to secondhand smoke. Common symptoms of SCC may includes chest pain, coughing up blood, weight loss and persistent cough. Treatments can be similar to those for adenocarcinoma. Early detection improves prognosis, with over 80% survival rates at five and ten years in early stage cases.
Large cell carcinoma
Large cell carcinoma(LCC) is a rare and aggressive subtype of Non-Small cell lung cancer, accounting for about 10-15% of all lung cancer cases. Large cell carcinoma (LCC) is named according to the cancer cells, large, abnormal- looking cells appearances under a microscope. This type of cancer cells can developed anywhere in the lungs, most commonly in the outer edges. It tends to grow more quickly and spread faster as compared to other forms of Non-Small cell lung cancer, making it harder to detect in early stages. Smoking is major risk factor but it can also occurs in non smokers due to environmental and genetic changes. LCC does not have a distinct features, which makes diagnosis challenging. Symptoms and Treatments of LCC can be similar to those of other forms of Non-Small cell lung cancer.
2. Small Cell Lung Cancer (SCLC) : It is a rare and highly aggressive type of lung cancer, accounting for about 10-15% of all lung cancer cases. In small cell lung cancer (SCLC), the cancer cells are smaller in size but spread more quickly as compared to Non-Small cell lung cancer (NSCLC).
Small Cell lung cancer has 2 major subtypes : Small cell carcinoma and Combined small cell carcinoma.
Small cell carcinoma is the one of the most common type of small cell lung cancer (SCLC), accounting for majority of SCLC cases. It is a highly aggressive and fast-growing cancer typically begins in the bronchi and rapidly spread to the other part of the body including liver, lymph nodes, brain and bones. It is most commonly found in smokers and rarely found in non-smokers. In small cell carcinoma , cancer cells appear small, round and densely packed with little cytoplasm, under a microscope. Treatments usually involves radiation and chemotherapy, due to cells aggressive nature.
Combined small cell carcinoma is also known as mixed small cell carcinoma, it is a rare subtype of small cell lung cancer (SCLC). Combined small cell carcinoma contains both small cell carcinoma and non-small cell lung cancer, such as adenocarcinoma and squamous cell carcinoma. It represents small percentage of small cell lung cancer cases. It is highly aggressive and rapidly grow. This mixed composition of cells can make treatment and diagnosis more challenging. They may not respond uniformly to standard therapies of small lung cell cancer.