Identification of Response Predictors to Temozolomide-Based Chemotherapy

#1245

Introduction: Capecitabine and temozolomide are active in the treatment of metastatic pNETs, with response rates ranging from 30% to 70%. Several small retrospective series have suggested that MGMT deficiency may predict response to temozolomide, however expression of MGMT has not been validated as a predictive biomarker. Cytotoxic chemotherapy is thought to be most active in aggressive tumors, however the ki-67 index has not been formally evaluated as a predictive factor. It is unclear whether chromosomal instability (which correlates with alternate lengthening of telomeres) predicts response.

Aim(s): To identify predictive biomarkers of response to cape/tem in patients with pNETs.

Materials and methods: 144 patients with pNET who underwent treatment with cape/tem were retrospectively evaluated for radiographic response. The predictive role of ki-67% and MGMT by IHC as well as ALT activation by FISH was assessed on up to 59 evaluable archival specimens. Frequently altered genes in pNETs were also sequenced and their status was correlated to the radiographic response.

Conference: 12th Annual ENETSConcerence (2015)

Presenting Author: Strosberg J

Authors: Strosberg J, Cives M, Brelsford M, Black M, Meeker A,

Keywords: ki67, MGMT, ALT, chromosomal instability, temozolomide, capecitabine, pNET,