Small cell lung cancer is a distinct form of lung cancer due to its clinical and biological characteristics. A recent study suggests that fighting these cell lines can provide better insights into overcoming chemotherapy resistance.
What is Small Cell Lung Cancer?
Small cell lung cancer (SCLC) is a rare form of fast-growing lung cancer, previously known as oat cell carcinoma. Although it is less common than non-small cell lung cancer, it represents about 15% of cancer diagnoses in the U.S.
Small-cell lung cancer begins when the healthy cells in a person's lungs undergo mutations or change into cancerous cells. As the cells divide and multiply uncontrollably, they clump together in the form of masses or tumors in the lungs. These tumors may shed cancer cells that can be picked up in the blood or lymph and carried throughout the body.
Aside from the lymph nodes and blood vessels, small-cell lung cancer can also spread to the bones, brain, liver, and adrenal glands. Once they spread, the cells may create new cancerous tumors in the lymph nodes and organs. They can also cause fluid build-up in the lungs or in the space around the lungs. As a result, the lung may collapse by pushing the air out in a process called pleural effusion.
Cases of small cell lung cancer that have not spread rarely cause symptoms. When symptoms happen, they may include chest pain, chronic cough, coughing up blood (hemoptysis), and facial swelling. Patients may also suffer from fatigue, hoarseness, swollen neck veins, and unexplained weight loss.
Anyone can get lung cancer, but people who smoke or are exposed to second-hand smoke have an increased risk of developing small-cell lung cancer. There are other risk factors, including family history, exposure to radon gas, radiation from cancer treatments or imaging scans, and exposure to workplace hazards such as nickel, arsenic, and asbestos.
Understanding the Resistance Mechanisms of SCLC
SCLC tumors usually develop resistance to chemotherapy, with poor prognosis due to tumor recurrence occurring within only five to 14 months after the initial diagnosis. In a research study conducted by Balazs Döme and Karin Schelch from MedUni Vienna, it was found that resistant cell lines can be successfully defeated using a combination of available therapeutic agents, providing a better approach to developing a new treatment for this aggressive type of tumor.
The research follows from previous findings, which suggest that small-cell lung cancer can be divided into subtypes that respond differently to chemotherapeutic agents and targeted medications. In this new study, histone deacetylase inhibitors (HDACi) were shown to be effective in two subtypes of small cell lung cancer known as SCLC-A and SCLC-N.
According to Schelch, the high mortality rate of small cell lung cancer is due to the rapid and inevitable recurrence of the disease, which is usually accompanied by resistance to treatment such as chemotherapy. In combination with standard chemotherapeutic agents, HDACi turned out to be a possible solution, as it was found to slow down the growth of tumor cells, which show resistance to individual therapy.
Further analysis also revealed the molecular mechanism underlying therapy resistance of small cell lung cancer. The research team is also hopeful that their findings can provide the basis for research into improved therapies that are far superior to the resistance mechanisms of SCLC.
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