TITLE:
Clinical Predictors of Cetuximab for First-Line Therapy of Metastatic Colorectal Cancer: A Single Institutional Retrospective Study
AUTHORS:
Yuki Morishita, Hiroaki Tanioka, Motoi Asano, Kotomi Tokuyama, Hiroko Okamoto, Tomohisa Okamoto, Takako Oda, Masatoshi Ohta, Masayuki Fukuzawa
KEYWORDS:
Cetuximab, Colorectal Cancer, Clinical Predictor
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.8 No.9,
September
12,
2017
ABSTRACT: Predictive
factors of cetuximab efficacy for metastatic colorectal cancer (mCRC) have not
been sufficiently revealed. The present study aimed to explore new predictors. A total of 30 patients with KRAS exon 2 wild-type unresectable mCRC, who
had been treated with cetuximab-based regimen as first-line therapy, were
retrospectively analyzed. We assessed whether gender, age, primary tumor site,
RAS genotype, the Eastern Cooperative Oncology Group Performance Status (ECOG
PS), metastatic status, histological grade, carcinoembryonic antigen (CEA),
treatment regimen, and oxaliplatin-based adjuvant chemotherapy at baseline were
associated with cetuximab efficacy. Progression-free survival (PFS) and
objective response rate (ORR) were evaluated and statistically analyzed.
Analysis of PFS revealed that left-sided tumor and good PS had relevance to
good results. PFS among patients with left-sided CRC was longer than that among
those with right-sided CRC (median, 10.6 and 3.5 months, respectively).
Patients with a PS of 0 - 1 experienced significantly longer PFS than those
with a PS of 2 - 3 (median, 8.6 versus 1.3 months, respectively). In analysis
of ORR, high histological grade and serum CEA level showed interaction with
good effect. Patients with histological grade I/II cancer experienced better
ORR than those with histological grade III/IV cancer (76% versus 20%,
respectively). ORR among patients with serum CEA level higher than 5.0 ng/ml
was significantly higher than that among those with lower serum levels (88%
versus 38%, respectively). ECOG PS, tumor location, histological grade, and serum CEA level at
baseline might be useful predictors of cetuximab efficacy in the first-line treatment
of mCRC.