Small Cell Lung Cancer - Extensive Stage

Summary:
Extensive stage small cell lung cancer is best managed by cisplatin and etoposide chemotherapy.

Prophylactic cranial irradiation of 25 Gy in 10 fractions should be offered to all patients who have any response to chemotherapy on the basis that it improves survival rates.

In an exam setting, DO NOT offer thoracic irradiation for these patients. There is no good evidence to support this practice, even though this is done in clinical practice to prevent obstructive symptoms.

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Extensive Stage Small Cell Lung Cancer is defined as disease that can not be encompassed within one radiation port. The decision to consider contralateral mediastinal or supraclavicular lymph nodes as extensive or limited stage disease is controversy and management decisions are largely clinician and patient dependent.

Management of extensive stage small cell lung cancer is primarily by cisplatin & etoposide chemotherapy for 4 - 6 cycles. Patients who have any kind of response to chemotherapy should receive prophylactic cranial irradiation (PCI). There is no evidence to support the use of consolidative thoracic irradiation following chemotherapy. Instances where this is considered is based on the fact that many patients will relapse in the original sites of disease. Adding radiation will not affect survival, but will decrease the rate of local relapse.

PCI has been proven to increase survival at 2 years by the PCI EORTC trial. This study randomized patients with extensive stage small cell lung cancer who had demonstrable response to chemotherapy to either observation or PCI. The PCI ranged in dose from 20 Gy in 5 fractions to 30 Gy in 10 fractions. This study demonstrated a 27% 1 year survival rate for PCI compared to 13% for observation. Quality of life measures demonstrated more fatigue in the PCI arm, but no detectable changes in quality of life or neurotoxicity.

Dose of PCI is an extrapolation from limited stage SCLC, based on the EORTC study by Le Pechoux, demonstrated no difference between higher dose PCI 36 Gy in 18 fractions versus a standard regimen 25 Gy in 10 fractions.

There is no role for consolidative radiation after a patient has completed chemotherapy. The weight of the evidence shows no benefit in terms of overall survival. Some oncologists may consider consolidation radiation to decrease local relapse rates and avoid death by lung failure, but with the knowledge that this will not prolong survival.