Prophylactic cranial irradiation in limited small-cell lung cancer: incidence of brain metastasis and survival and clinical aspects

Suh, Jae Chul; Kim, Myung Hoon; Park, Hee Sun; Kang, Dong Won; Lee, Kyu Seung; Ko, Dong Seok; Kim, Geun Hwa; Jeong, Seong Su; Cho, Moon June; Kim, Ju Ock; Kim, Sun Young

Abstract

PURPOSE
Brain metastases are present in approximately 10-16% of small cell lung cancer patients at diagnosis. Brain metastasis is an important clinical problem associated with increasing the survival rate, with a cumulative incidence of up to 80% in patients surviving 2 years. Prophylactic cranial irradiation(PCI reduces the incidence of brain matastasis and may prolong survival in patients with limited small-cell lung cancer who achieved complete remission. This study was performed to analyze the incidence of brain metastasis, survival and clinical aspects after PCI in patients with limited small-cell lung cancer who achieved complete remission.
METHODS
Between 1989 and 1999, forty-two patients with limited small-cell lung cancer who achived achieved complete remission after therapy were enrolled into this study retrospectively. All patients received etoposide and cisplatin(VPP) alternating with cytoxan, adriamycin, and vincristine(CAV) every 3 weeks for at least 6 cycles initially. All patients received thoracic radiotherapy:concurrent(38.1%) and sequentia(61.9%). All patients received late PCI.
RESULTS
Most patients(88.1%) were men, and the median age was 58 years. The median follow-up duration was 18.1 months. During the follow-up period, 57.1% of the patients developed relapse. The most frequent site of relapse was chest(35.7%), followed by brain(14.3%), liver(11.9%), adrenal gland(4.4%), and bone(2.2%). With the Kaplan-Meier method, the average disease-free interval was 1,090 days(median 305 days). The average time to development of brain relapse after PCI and other sites relapse(except brain) were 2,548 days and 1,395 days(median 460 days), respectively. The average overall survival was 1,233 days(median 634 days, 21.1 months), and 2-year survival rates was 41.7%. The average overall survival in the relapse group was 642 days(median 489 days) and in the no relapse group was 2,622 days(p<0.001). The average overall survival in the brain relapse guoup was 928 days(median 822 days) and in the no brain relapse group was 1,308 days(median 634 days)(p=0.772). In most patients(85.7%), relepse(expect brain) or systemic disease was the usual cause of death. Brain matastasis was the cause of death in 14.3% of the cases.
CONCLUSIONS
We may conclude that PCI reduces and delays brain metastasis in patients with limited small-cell lung cancer who achieved complete remission. We found decreased survival in relapse group but, no significant survival difference was noted according to brain matastasis. And relapse(except brain) or systemic disease was the usual cause of death. In order to increase survival, new treatment strategies for control methods for relapse and systemic disease are required.