Correlation between Primary Tumor Location and Brain Metastasis Development or Peritumoral Brain Edema in Lung Cancer

In lung cancer overall survival and quality of life are affected adversely by brain metastases, while peritumoral brain edema is responsible for life-threatening complications. The clinicopathological and cerebral radiological data of 575 consecutive lung cancer patients with brain metastases were analyzed retrospectively. In squamous cell carcinoma (SCC) and adenocarcinoma (ADC) peritumoral brain edema was more pronounced as compared with small cell lung cancer (SCLC) (p<0.001, p˂0.001, respectively). There was positive correlation between size of metastasis and thickness of peritumoral brain edema (p<0.001). It was thicker in supratentorial tumors (p=0.019), in younger patients (≤50 years) (p=0.042), and in females (p=0.016). The interval time to brain metastasis was shorter in case of central as compared with peripheral lung cancer (5.3 vs. 9.0 months, p=0.035). Early brain metastasis was characteristic for ADCs. A total of 135 patients had brain only metastases (N0 disease) characterized by peripheral lung cancer predominance (p<0.001), and longer time-to-metastasis interval (9.2 vs. 4.4 months, p<0.001). Overall survival was longer in the brain only subgroup than in patients with N1-3 diseases (p<0.001). According to our results, clinicopathological characteristics of lung cancer are related to the development and radiographic features of brain metastases, and these findings might be helpful in selecting patients who could benefit from prophylactic cranial irradiation.