Resectable central nervous system (CNS) metastases from colorectal cancer (CRC): Patient characteristics, outcome, and molecular correlations between primary tumor and metastases.

Abstract

2084 Background: Aim of this study is to describe clinical characteristics and outcome of CRC patients with CNS metastases undergone to surgical resection, and report preliminary data on the comparison between molecular aspects of primary tumor and metastasis. Methods: Thirty-two pts (17 males, 15 females) with a median age of 65 yrs (range 38-80 yrs) with brain metastases from colon (23 pts, 72%) or rectum (9 pts; 28% ) adenocarcinoma (G1 in 3 pts, 9%; G2 in 12 pts, 37%; G3 in 17 pts, 53%) underwent total surgical resection. Primary tumor TNM was: T2 in 1 pt (3%), T3 in 22 pts (69%) and T4 in 9 pts (28 %); no patient had N0 status , 10 pts had N1 lesions (31%) and 22 pts had N2 (69%) lesions; 25 pts were M0 (78%) while 7 (22%) were M1. Results: One patient had neurological symptoms as first manifestation of CRC; the other cases had metachronous metastases in the SNC after a median of 35.5 months (range 4-96). The CNS location was cerebellum in 15 pts (47 %), frontal lobe in 9 pts (28 %), spinal cord in 5 pts (16% ), parietal lobe in 2 pts (6%) and occipital lobe in 1 pt (3%). Perioperative mortality was 3%. Ten pts (31%) received post-operative whole-brain radiotherapy. Six patient (19%) had local recurrence. Primary cancers harbored a K-RAS mutation in 13 cases (41%) and a BRAF mutation in 1 case (3%). Preliminary data in 20 pts indicate a 100% mutation concordance between primary tumor and CNS metastases. Conclusions: Resectable CNS metastases from CRC adenocarcinoma were seen after a median of 3 yrs originating from T3-4 N1-2 M0-1 lesions. The preferential locations in the CNS were cerebellum and frontal lobe, being spinal metastases relatively frequent. The total resection was feasible with a good long-term local control ; the whole-brain irradiation given to one third of cases could have contributed to local control. Almost all pts died of extranervous metastases. There was a concordance of KRAS and BRAF mutation in primary and CNS lesions.