Chemo and Radiation for Small Cell Lung Cancer

The lethal nature of small cell lung cancer (SCLC) is highlighted by the fact that very few of the cases can be treated with surgery by the time they are diagnosed.  The disease develops so rapidly that it is rarely discovered until it has grown beyond the point where it can be removed surgically.  In a few rare cases the tumor may be resected, but in the vast majority of them the treatment options are confined to chemotherapy and radiation.

Treating Types of Small Cell Lung Cancer

There are two subdivisions for this disease based on the types of cells that characterize the tumor.  All small cell lung cancer malignancies have what are called oat cells: small, flat cells that do not contain a lot of cytoplasm.  If that is the only type of cancer cell found in the tumor, the disease is diagnosed as oat cell lung cancer.  The other possibility is mixed small cell lung cancer, a form of the disease that manifests both oat cells and some type of non-small cell lung cancer cell as well.  Treatment protocols for the two types of the disease vary.

Oat Cell Lung Cancer Treatment

This particular type of cell has shown to be highly responsive to chemotherapy; usually initiated using one of these drugs: cisplatin, doxorubicin, etoposide, vincristine, and/or paclitaxel.  Response rates among patients can be between 40% and 90% using chemotherapy alone.   Half or more of those individuals show a “complete response,” which means the disappearance of all evidence of malignant cells.  Unfortunately relapse is the rule rather than the exception and develops fairly rapidly.  Radiation is used as well in treating oat cell lung cancer; the cells have proven to respond to radiotherapy as well.

Mixed Small Cell Lung Cancer Treatment

This form of the cancer has two types of cells to be reduced which require two clinical angles of attack.  The mixture of chemotherapy drugs in particular is going to vary depending on the type of non-small cell malignancy that is present.  Along with the oat cells there may be squamous cells, spindle cells, sarcomatoid cells or epithelial cells present, each of which responds to different types of drugs.  Carboplatin, gemcitabine, vinorelbine, and irinotecan may be used in combination with cisplatin or one of the other common drugs listed above.

Radiation is used to treat both types of SCLC, typically with good response.  The use of radiation is dictated by the location(s) of malignant tissue, meaning that treatment on multiple parts of the body may be required.  Radiation treatment is another instance of SCLC that can result in initial elimination of the cancer cells but in most cases is followed by recurrence of the disease.

Cranial Irradiation

Migration of SCLC to the brain is not uncommon and generally is treated with radiation.  In patients with extended or widespread small cell lung cancer the doctor may choose to apply radiation to the cranium even if there has been no diagnosis of cancer there.  This treatment is called prophylactic cranial irradiation (PCI); the randomized trials for the procedure indicate that it can contribute to survival time and that there are generally no ill effects on cognition.

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