Contradictory KRAS mutation test results in a patient with metastatic colon cancer: a clinical dilemma in the era of personalized medicine.

Publication/Presentation Date

8-1-2013

Abstract

The KRAS oncogene is mutated in 40‒50% of colorectal cancers and confers resistance to EGFR-targeted therapy. In the clinic, agents such as cetuximab or panitumumab target the EGFR receptor for therapeutic benefit. Cetuximab was approved by the FDA in 2012 as first-line therapy for KRAS mutation-negative (wild-type), EGFR-expressing metastatic colorectal cancer, in combination with FOLFIRI (5-fluorouracil, irinotecan, leucovorin). Herein we report a case of metastatic colon cancer with conflicting testing results for the KRAS oncogene from two different reference laboratories. The discordant reports complicated the decision-making process regarding the administration of targeted anti-EGFR personalized therapy. As the second test result was wild-type from the same original pathological specimen, the patient was treated with cetuximab-containing combination chemotherapy and appeared to have a response after prior disease progression. It is unclear whether the observed response was fully due to regression of wild-type KRAS-containing tumor or any component of antibody-dependent cellular cytotoxicity to a heterogeneous tumor in this patient.

Volume

14

Issue

8

First Page

699

Last Page

702

ISSN

1555-8576

Disciplines

Medicine and Health Sciences

PubMedID

23792572

Department(s)

Department of Medicine, Hematology-Medical Oncology Division

Document Type

Article

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