High incidence of ischemic stroke occurrence in irradiated lung cancer patients: a population-based surgical cohort study.
OBJECTIVE
A high risk of stroke occurrence has been reported in several types of irradiated cancer patients. However, clinical data are lacking in irradiated lung cancer patients. The present study intended to explore a risk level of ischemic stroke occurrence in irradiated lung cancer patients.


METHODS
A nationwide population-based database obtained from the Taiwan National Health Insurance was analyzed. Between 2003 and 2006, we recruited 560 resected lung cancer patients into two study groups: surgery-plus-irradiation (n = 112) and surgery-alone (n = 448). Patients treated with chemotherapy were excluded. Propensity score match was used for pairing cases with a ratio of 1∶4. Two-year ischemic-stroke-free survival was defined as the primary endpoint.


RESULTS
Three observations supported a high risk of ischemic stroke occurrence in patients with postoperative irradiation when compared with those patients with surgery alone: first, a high incidence per 1,000 person-year (22.3 versus 11.2, 1.99 folds); second, a low two-year ischemic-stroke-free survival rate (92.2% versus 98.1%, P = 0.019); and third, a high adjusted hazard ratio (HR, 4.19; 95% CI, 1.44-12.22; P = 0.009). More notably, the highest risk of ischemic stroke occurrence was found in irradiated patients who had diabetes mellitus (HR, 34.74; 95% CI, 6.35->100; P<0.0001).


CONCLUSIONS
A high incidence of ischemic stroke was observed in irradiated lung cancer patients, especially in those with diabetes mellitus. For these patients, close clinical surveillance and strict diabetes control should be considered. Further studies to define detail biological mechanisms are encouraged.
Departments of Radiation Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Shih-Kai
SK
Hung
Departments of Radiation Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Moon-Sing
MS
Lee
Departments of Radiation Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Wen-Yen
WY
Chiou
Department of Otolaryngology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Ching-Chih
CC
Lee
Division of Nephrology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Yi-Chun
YC
Chen
Division of Chest Medicine, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Chun-Liang
CL
Lai
Division of Thoracic Surgery, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Nai-Chuan
NC
Chien
Department of Radiation Oncology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Wen-Lin
WL
Hsu
Department of Radiation Oncology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Dai-Wei
DW
Liu
Division of Hematology-Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Yu-Chieh
YC
Su
Division of Hematology-Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Szu-Chi
SC
Li
Division of Hematology-Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC.
Hung-Chih
HC
Lai
Departments of Radiation Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC.
Shiang-Jiun
SJ
Tsai
Departments of Radiation Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC.
Feng-Chun
FC
Hsu
Departments of Radiation Oncology, Buddhist Dalin Tzu Chi Hospital, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC; Institute of Molecular Biology, National Chung Cheng University, Min-Hsiung, Chia-Yi, Taiwan, ROC.
Hon-Yi
HY
Lin
D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000150:complications*; D015331:Cohort Studies; D048909:Diabetes Complications / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011184:Postoperative Period; D011832:Radiation Injuries / Q000150:complications* / Q000209:etiology*; D012307:Risk Factors; D020521:Stroke / Q000150:complications* / Q000209:etiology*