Prophylactic Cranial Irradiation in Adenocarcinoma of the Lung z A Possible Role zyxw RENEE H. JACOBS, MD, AZHAR AWAN, MD, JACOB D. BITRAN, MD, PHILIP C. HOFFMAN, MD, ALEX G. LITTLE, MD, MARK K. FERGUSON, MD. RALPH WEICHSELBAUM, MD, AND HARVEY M. GOLOMB. MD zyxwv Seventy-eight patients with modified Stage zyxwvuts I1 or Stage IIIMO adenocarcinoma of the lung were evaluated retrospectively with regard to the impact of prophylactic cranial irradiation (PCI) (30 Gy in 15 fractions) in preventing central nervous system (CNS) metastases. Twenty patients received PCI and 58 did not. There were no significant differences between these groups with respect to age, sex, stage, or median survival (17.4 months with PCI versus 16.9 months without PCI; zyxw P zyxw = 0.6). One zyxw (5%) of 20 patients receiving PCI developed CNS metastases, compared with 14 (24%) of 58 patients not receiving PCI (P = 0.06). The time from diagnosis to development of CNS metastases and survival after CNS involvement was 51 weeks and 14 weeks, respectively, for the patient who received PCI; and a median time of 50 weeks and 26 weeks, respectively, for the patients not receiving PCI. In nine (64%) of the 14 non-PCI patients the CNS was the first and only site of relapse. A Cox regression analysis demonstrated that nodal involvement was significantly associated with an increased risk of CNS metastases. These data suggest that PCI may decrease the incidence of CNS metastases, and that it may be beneficial in the management of patients with N1 or N2 disease. Cancer 59:2016-2019, 1987. HE ROLE OF PROPHYLACTIC CRANIAL IRRADIATION T (PCI) in adenocarcinoma of the lung is undefined. In small cell lung carcinoma (SCLC) PCI decreases the incidence of central nervous system (CNS) relapse from 22% to 8%.*,* From clinical and autopsy series in non- small cell lung carcinoma (NSCLC) distant metastases in patients with adenocarcinoma are frequent and often the only site of relap~e.~ Specifically, CNS metastases occur in 39% to 57% of patients with adenocarcinoma, com- pared with 17% to 27% of patients with squamous cell carcin~ma.~?~ In 1980, we reported our experience with combined modality therapy in NSCLC. The CNS was the first site of relapse in 38% of patients with adenocarcinoma, com- pared with no CNS metastases in patients with squamous cell carcinoma (P = 0.001).6 As a result, in 198 1 PCI was added to the treatment of all patients with modified Stage I1 and Stage IIIMO adenocarcinoma of the lung. This study retrospectively evaluates the impact of PCI in preventing CNS relapse among patients with adenocarcinoma of the lung. ~ From the Departments of Medicine, Surgery, and Ra&ation Oncology, University of Chicago and Michael Reese Medical Center, Joint Section of Hematology/Oncology, Chicago, Illinois. Address for reprints: Renee H. Jacobs, MD, 5841 S. Maryland Avenue, Box 420, Chicago, IL 60637. Accepted for publication December 30, 1986. Materials and Methods The charts of all patients seen at the University of Chi- cago since 1975 with histologically proven modified Stage I1 or Stage IIIMO adenocarcinoma of the lung were retro- spectively reviewed. Initial staging included a history and physical examination, complete blood count, chemistry profile (including renal and liver function studies), chest x-ray, liver scan, bone scan, brain CT scan, and gallium scan. In 1983, we began to obtain computed axial to- mographic (CT) scans of the chest and upper abdomen to the level of the adrenal glands for mediastinal staging and to screen for clinically silent adrenal metastases. Patients were staged with a modification of the TNM classification of the Task Force on Carcinoma of the Lung.’ Patients were classified as modified Stage I if they had T 1 NOMO or T2NOMO disease and as modified Stage I1 if they had T 1 N1 MO or T2N 1 MO disease. Patients with Stage IIIMO disease had locally advanced disease without distant spread. Patients with disease metastatic to supra- clavicular nodes or with malignant pleural effusions were excluded from the study. All patients with clinical Stage I and I1 disease had sur- gical resection of their disease, unless contraindicated by a coexisting medical illness. Of this group, only patients with pathologic Stage I1 or IIIMO disease were included in this study. 2016