Treatment of Small Cell Lung Cancer

Chemotherapy is the main treatment for limited- and extensive-stage SCLC. Since SCLC grows quickly and is usually diagnosed in the later stages when it has already spread, systemic treatments like chemotherapy are more effective than localized treatments like radiation and surgery. Treatment of limited-stage SCLC begins with chemoradiation—a combination of chemotherapy and radiation. If the lung tumour responds well to this regimen, your doctor may recommend preventative radiation to the brain. Surgery is rarely part of the treatment plan, and is always used in combination with other treatments. In the extensive stage, chemotherapy is given first. There are currently no effective targeted therapies or immunotherapies for SCLC, but these are areas of active research in clinical trials.

Usually a combination of two chemotherapy drugs—commonly etoposide and a platinum-containing drug such as cisplatin or carboplatin—is used. Some combination regimens may use a chemotherapy drug called irinotecan instead of etoposide. If you cannot tolerate combination treatment, you will be treated with only etoposide. New evidence has emerged suggesting that combining chemotherapy with platinum and etoposide with a PD-L1 inhibitor, atezolizumab (Tecentriq™) may be beneficial in the first line treatment of extensive stage small cell. Speak to your physician to see if this triplet therapy is appropriate for you.
Recurrent cancer is also treated with etoposide, topotecan, or with a combination of three chemotherapy drugs—cyclophosphamide, doxorubicin, and vincristine. 

For limited-stage cancer, radiation treatment will be part of the chemoradiation regimen. For extensive-stage cancer, radiation treatment may be palliative—that is, with the goal of shrinking tumours to relieve symptoms like trouble with swallowing or breathing problems. Prophylactic cranial irradiation (PCI) is a type of radiation treatment used to kill cancer cells in the brain. PCI may be included in the treatment plans for limitedstage cancer that has responded well to chemoradiation, and for extensive-stage cancer that has responded well to chemotherapy. As its name suggests, PCI treatment is prophylactic—that is, it is used to prevent the spread of cancer to the brain, a common site of metastasis in SCLC. So, PCI may be used even if cancer cells do not show up on x-rays or scans of the brain, and can significantly reduce the chance of developing brain metastases. If the presence of brain metastases has been confirmed, external beam radiation therapy is used. 

Currently, surgery is not a standard part of treatment plans for SCLC. If SCLC is diagnosed in the limited stage, and the tumour is small and can be completely removed, and pulmonary function tests (PFTs) indicate that it is feasible to remove all or part of a lung, then surgery might be the first treatment given. But such cases are rare. When surgery is part of the treatment plan, an entire lobe of the lung is usually removed. Doing this offers a greater chance of removing all the cancer compared to when smaller parts of the lung are removed. Nearby lymph nodes or tissue samples are also removed at the same time.