Histopathologic analysis of brain metastasis in pulmonary adenocarcinoma: Necrosis is a new risk factor.

BACKGROUND: Studies have shown that 30-50% of non-small cell lung cancer (NSCLC) patients develop brain metastasis (BM). Since BM shortens overall survival and decreases the quality of life, early detection and treatment of BM are vital. While data are available for clinical risk factors of NSCLC with BM, histopathological factors are not well understood. Therefore, we evaluated the histopathological related factors which will help early detection and selection of effective treatment options.

MATERIALS AND METHODS: A total of 117 surgical lung specimens diagnosed as NSCLC with BM were included as a study group. We included 237 cases without BM as a control group. One pathologist reviewed H&E slides and analyzed the histopathologic factors of all cases.

RESULTS: In pulmonary adenocarcinoma, vascular invasion, N stage, micropapillary pattern and necrosis were significantly associated with BM in multivariate analysis (vascular invasion, p = 0.009; micropapillary pattern, p = 0.024; others, p < 0.001). Tumor with extensive necrosis had higher hazard ratio and shorter time to BM (p < 0.001).

CONCLUSION: Our findings suggest that necrosis is a new predictive factor of BM in pulmonary adenocarcinoma. Short term follow-up is needed especially when extensive necrosis is present.