The origin of cancer cells
All cells in the body do a specific task. For example, platelets prevent bleeding, red blood cells carry nutrients and oxygen, while white blood cells protect the body from diseases. All these intertwine to keep the body functional. However, cells don’t live forever; otherwise, the body would be a batch of old non-functional cells.
In due course, old cells are destroyed and replaced with new ones to keep our systems well oiled. However, some cells have abnormal DNA and resist destruction and continually grow. Afterward, these cells transform into a tissue called a tumor – a collection of cells that always produce and are not destroyed and are harmful to the body.
A malignant tumor can grow anywhere in the body, destroy and invade into other tissues.
As long as there is nothing abnormal, cells that line the respiratory system; the lungs and alveoli, trachea, pleural tissue and glands, function as required. When we breathe in, oxygen is absorbed and swapped with toxic carbon dioxide. In some cases, these cells lose their function and transform into a cancer of the lungs.
If these cells grow unchecked, they become malignant, spread into other parts of the body, and damage more organs.
Some tumors, such as a hamartoma or papilloma, are harmless to the body. They are non-invasive or damage other tissues. However, these seemingly harmless tissues have the potential of becoming malignant.
Malignant and Destructive Lung Cancers
There are two categories of lung cancers based on the cells from which they grow from; they include non-small cell lung cancers (NSCLC) and small cell lung cancers (SCLC).
Non–Small Cell Lung Cancer (NSCLC)
Tumors of glandular cells that dominate outer parts of the lungs are called adenocarcinoma. Squamous epithelium that lines the trachea or windpipe is the origin of NSCLS tumors known as squamous cell carcinomas. Sarcomas and sarcomatoid are other rare cancers that affect larger cells of the lungs.
Small Cell Lung Cancer (SCLC)
Small cell lung cancers are common in the central part of the lungs. They seed in tiny cells that are local to bronchi or larger windpipe and are known as carcinomas. When a small cell carcinoma merges with larger squamous, glandular cells, the result is a combined small cell carcinoma.
Lung Carcinoid Tumor
Lung carcinoid tumors, aka neuroendocrine tumors, are a rare group of tumors that grow slowly and are non-invasive, and these account for less than 5% of lung tumors.
The pleural membrane secretes a special fluid that lubricates the lungs. Sometimes cells of the pleural membrane are the origin of a rare tumor known as pleural mesothelioma that is different from tumors of glandular cells and small cell carcinomas.
A tumor that grows from the lung is primary lung cancer. Sometimes it gets malignant and invades distant tissues in the body. This can also happen in reverse where a tumor from other parts of the body invades the lungs and becomes a malignant tumor. This phenomenon is known as lung metastasis.