Predictive factors for the efficacy of cetuximab plus chemotherapy as salvage therapy in metastatic gastric cancer patients.
OBJECTIVE
We performed a retrospective study to evaluate the efficacy of cetuximab plus chemotherapy in metastatic gastric cancer (MGC) patients previously treated with chemotherapy and to investigate potential predictors of treatment efficacy in those patients.


METHODS
Thirty-two patients with MGC were included in this study. Cetuximab was delivered, often combined with irinotecan-based chemotherapy. Thirty patients were analyzed for K-ras mutations via direct sequencing of the tumor DNA.


RESULTS
Patients were heavily pretreated with a median number of three previous lines of palliative chemotherapy (56% of the patients were refractory to all of the following drugs: fluoropyrimidines, cisplatin, irinotecan, oxaliplatin, and docetaxel) and 53% of the patients displayed poor performance status. Of 28 response-assessable patients, the overall response rate to cetuximab plus chemotherapy was 3.6% [95% confidence interval (CI) 0-10.5%] and the disease control rate was 28.6%. The median progression-free survival (PFS) was 1.7 months (95% CI 1.3-2.1 months), and the median overall survival (OS) was 3.2 months (95% CI 1.4-5.0 months). Multivariate analyses revealed that skin rash and performance status were significantly associated with PFS and OS. The presence of a K-ras mutation (13.3%) was not associated with either PFS or OS.


CONCLUSIONS
Our study suggests that MGC patients with good performance status and skin rash benefit most from salvage cetuximab combined with chemotherapy, even in heavily pretreated status.
Park
Sook Ryun
SR
Center for Gastric Cancer, Research Institute and Hospital, National Cancer Center, 111 Jungbalsan-ro, Ilsandong-gu, Goyang, Gyeonggi, 410-769, Republic of Korea. sukryun73@hanmail.net
Kook
Myeong-Cherl
MC
Choi
Il Ju
IJ
Kim
Chan Gyoo
CG
Lee
Jong Yeul
JY
Cho
Soo-Jeong
SJ
Kim
Young-Woo
YW
Ryu
Keun Won
KW
Lee
Jun Ho
JH
Lee
Jong Seok
JS
Park
Young-Iee
YI
Kim
Noe Kyeong
NK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000009:adverse effects; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D000068818:Cetuximab; D004252:DNA Mutational Analysis; D005076:Exanthema / Q000139:chemically induced; D005260:Female; D006801:Humans; D000077146:Irinotecan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D012189:Retrospective Studies; D016879:Salvage Therapy; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D016019:Survival Analysis; D016896:Treatment Outcome; D018631:ras Proteins / Q000235:genetics
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D000077146:Irinotecan; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab; D002166:Camptothecin