Abstract
BACKGROUND
The diagnosis of a brain metastases is generally made during the follow up examinations of patients with primary known cancer. However, there are some patients presenting brain metastases as the first manifestation of a previously undiagnosed primary tumor (UDP) pathological confirmation of the diagnosis. The timing of a subsequent neurosurgical intervention is influenced by the distribution of primary tumors in UDP patients. The purpose of this study was to investigate the optimal diagnostic approach and the role of surgery for UDP patients.
METHODS
In a retrospective study, 35 patients admitted to our institution and underwent brain tumor removal from 2017 to 2019 with the diagnosis of cerebral metastases and diagnosed lung cancer as primary tumor subsequently, or previously diagnosed lung cancer.
RESULTS
UDP patients represented 46% of the whole group. Primary tumor subtype was the adenocarcinoma (n=13, 81%), small cell carcinoma (n=2, 13%), and neuroendocrine carcinoma (n=1, 6%). They did not have bronchoscopy nor excision of lung cancer. On the other hand, the patients previously diagnosed lung cancer represented 54% and subtype was adenocarcinoma (n=14, 74%) and small cell carcinoma (n=5, 26%). EGFR mutation was detected from 7 patients (44%) in UDP group and treated by EGFR tyrosine kinase inhibitor.
CONCLUSION
The significance of surgical intervention in metastatic brain tumors has been limited. However, active surgical intervention in UDP patients could identify not only histological diagnosis but also molecular biological characteristics. Our study suggests the possibility to avoid whole brain radiation in UDP patient by the active surgery.