KRASandBRAFgenotyping of synchronous colorectal carcinomas.
v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genotyping is required prior to anti-epidermal growth factor receptor monoclonal antibody therapy administered in cases of metastatic colorectal carcinoma (CRC). Thus,KRASmutation screening is required for patient management. The present study reported the experience ofKRAS/v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutational screening on synchronous CRC pairs from 26 patients, which were defined as index lesions (ILs) and concurrent lesions (CLs) on the basis of tumor grade and dimension and their respective lymph node and distant metastases. Overall,KRASmutations were present in 38.4% of patients, whereasBRAFmutations were present at a frequency of 11.5%. The genotyping of paired synchronous carcinomas indicated that 11 patients (42.3%) exhibited discordantKRASmutational statuses in terms of the presence of a mutation in only one lesion of the pair or of two different mutations harbored by each lesion.BRAFmutations were present in the synchronous tumors of two cases, whereas in two other cases, only the IL or CL harbored mutantBRAF.Overall, the mutational statuses of distant and lymph node metastases confirm the genetic heterogeneity of synchronous primary tumors. These results highlighted the fact that adequate sampling and comprehensive testing, when feasible, is likely to optimize the decision-making process for treatment approaches, even in the relatively rare event of multiple synchronous lesions.
Department of Surgery, University of Pisa, Pisa I-56126, Italy.
Riccardo
R
Giannini
Unit of Surgical Pathology 3, Pisa University Hospital, Pisa I-56126, Italy.
Cristiana
C
Lupi
Unit of Medical Oncology, Pisa University Hospital, Pisa I-56126, Italy.
Fotios
F
Loupakis
Department of Surgery, University of Pisa, Pisa I-56126, Italy.
Adele
A
Servadio
Unit of Medical Oncology, Pisa University Hospital, Pisa I-56126, Italy.
Chiara
C
Cremolini
Unit of Surgical Pathology 3, Pisa University Hospital, Pisa I-56126, Italy.
Elisa
E
Sensi
Department of Surgery, University of Pisa, Pisa I-56126, Italy.
Massimo
M
Chiarugi
Unit of Medical Oncology, Pisa University Hospital, Pisa I-56126, Italy.
Carlotta
C
Antoniotti
Department of Surgery, University of Pisa, Pisa I-56126, Italy.
Fulvio
F
Basolo
Unit of Medical Oncology, Pisa University Hospital, Pisa I-56126, Italy.
Alfredo
A
Falcone
Department of Surgery, University of Pisa, Pisa I-56126, Italy.
Gabriella
G
Fontanini
BRAF; KRAS; synchronous colorectal carcinomas