Effect of prophylactic cranial irradiation on survival in elderly patients with limited-stage small cell lung cancer.
BACKGROUND
Prophylactic cranial irradiation (PCI) improves survival in patients with limited-stage small cell lung cancer (SCLC) who have a complete response to chemotherapy and radiotherapy, yet to the best of the authors' knowledge, data specific to the elderly population are lacking.


METHODS
Using the Surveillance, Epidemiology, and End Results (SEER) database, the authors identified 1926 patients aged ≥ 70 years who were diagnosed with limited-stage SCLC between 1988 and 1997. Overall survival (OS) for patients who received PCI versus those who did not were estimated using the Kaplan-Meier method and compared with the log-rank test. A Cox proportional hazards model was further fitted to estimate the effect of PCI on OS after adjusting for age, race, sex, tumor size, lymph node status, stage of disease, and receipt of thoracic radiotherapy and surgery.


RESULTS
The median age of the patients was 75 years (range, 70 years-94 years) and 138 patients (7.2 %) received PCI. The 2-year and 5-year OS rates were 33.3% (95% confidence interval [95% CI], 25.6%-41.2%) and 11.6% (95% CI, 6.9%-17.6%), respectively, among patients who received PCI versus 23.1% (95% CI, 21.2%-25.1%) and 8.6% (95% CI, 7.3%-9.9%), respectively, among patients who did not receive PCI (P = .028). On multivariable analysis, PCI was found to be an independent predictor of OS (hazards ratio, 0.72; 95% CI, 0.54-0.97 [P = .032]). On subgroup analysis, PCI remained an independent predictor of OS among patients aged ≥ 75 years, but not among patients aged ≥ 80 years.


CONCLUSIONS
The receipt of PCI is associated with improved OS in patients aged ≥ 70 years with SCLC, suggesting that the benefit of PCI is maintained in the elderly population.
Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, Georgia.
Bree R
BR
Eaton
Sungjin
S
Kim
David M
DM
Marcus
Roshan
R
Prabhu
Zhengjia
Z
Chen
Suresh S
SS
Ramalingam
Walter J
WJ
Curran
Kristin A
KA
Higgins
D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000517:prevention & control* / Q000556:secondary; D016371:Cranial Irradiation / Q000009:adverse effects / Q000401:mortality / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D009367:Neoplasm Staging; D011379:Prognosis; D018426:SEER Program / Q000706:statistics & numerical data; D055502:Secondary Prevention / Q000379:methods; D055752:Small Cell Lung Carcinoma / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate
age; elderly; lung cancer; prophylactic cranial irradiation; small cell