Brain metastasis in lung cancer: Are there any predictive risk factors?

Abstract

e21740 Background: Lung cancer is the first cause of death by cancer worldwide. Brain metastases in lung cancer are associated to an even poorer prognosis of this cancer. Identifying patients with a higher risk of developing brain cancer may help their prognosis by including systematic brain radiotherapy to their treatment. But what are risk factors of brain metastasis occurrence in lung cancer patients? Methods: To answer this question, we conducted a case control study comparing two groups of lung cancer patients. The cases group included 35 lung cancer patients with brain metastasis at the moment of diagnosis while the control group was made of 49 lung cancer patient with no brain metastasis at the moment of diagnosis. Many parameters were compared between the two groups such as: professional exposure, type and duration of smoking, medical history, clinical and radiological presentation as well as the histological type of the carcinoma. Results: The mean age was 56 for the cases group and 61 for the control group. Nonsmokers represented 14% in the cases group and 4% in the control group. The average smoking was 34 pack-year for the cases group and 31 pack-year for the control group and in both groups 51% of patients smoked a mixture of tobacco and Cannabis. 36% of the control group patients had an exposure to a professional carcinogen while 48% of the cases group patients had one. Digital clubbing was found in 62% of cases group patients and in 51% of the control group patients. 17% of the cases group patients had two more metastases outside the lungs and other than the brain ones while this rate was only 6% for the control group patients. The mean level of LDH (Lactate Dehydrogenase) was 340 U/L for the cases group and 342 U/L for the control group while the CRP (C- reactive protein) one was 78 mg/L for the cases group and 59 mg/L for the control group. The main histological type found in both groups was Adenocarcinoma (25% in the cases group and 18% in the control group) followed by the poorly differentiated carcinoma in the cases group and the squamous cell carcinoma in the control group. Small cell carcinoma was found in 5% of the patients with brain metastases and in 8% of the patients without brain metastases. Conclusions: Patients with brain metastases have a higher professional carcinogens exposure, a higher percentage of nonsmokers, more digital clubbing, and higher CRP levels than patients with no brain metastases. They also have more than one metastasis at the moment of the diagnosis and the predominant histological types are Adenocarcinoma and poorly differentiated carcinoma.