C677T and A1298C MTHFR Polymorphisms and Fluoropyrimidine Effectiveness in Metastatic Colon Cancer

Universidad de Costa Rica65 enrolled

Overview

Fluoropyrimidines are the backbone of chemotherapy regimes used to treat metastatic colorectal cancer (CRC). These drugs act in different pathways of folate metabolism altering DNA synthesis mainly by inhibition of the tymidylate synthase. For this reaction the 5,10-methylenetetrahydrofolate acts as cofactor. It has been demonstrated that A1298C and C677T polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene result in reduced enzyme activity that leads to reduced availability of this important cofactor. Hence, we hypothesized that the presence of these polymorphisms are related to the efficacy and toxicity of fluoropyrimidines in patients with CRC.

Patients with metastatic colorectal cancer are invited to join this study at the start of treatment with any fluoropyrimidine used alone or in combination with oxaliplatin and/or irinotecan +/- bevacizumab, panitumumab or cetuximab. DNA extraction will be done from blood and tissue samples to determine the C677T (rs1801133) and 1298 A\>C (rs18011131) polymorphisms of the MTHFR gene. The patient will be followed at least for one year during treatment to determine any toxicity related to the therapy and to determine the overall survival, progression-free survival and response rate. Patients will be categorized into different categories according to the genetic status of each polymorphism.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Colon Cancer MTHFR Gene Mutation Chemotherapeutic Toxicity Chemotherapy Effect

Outcomes

Primary Outcomes

Assessment of C677T and A1298C MTHFR polymorphisms and overall survival

Overall survival

Time frame: From the start date of treatment until the date of death from any cause, assessed up to 24 months

Assessment of C677T and A1298C MTHFR polymorphisms and progression-free survival

Progression-Free survival

Time frame: From the start date of treatment until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 24 months

Assessment of C677T and A1298C MTHFR polymorphisms and response rate

Response rate

Time frame: From the start date of treatment until the first radiological or clinical assessment, up to 6 months.

Secondary Outcomes

Assessment of C677T and A1298 MTHFR polymorphisms and toxicity

Prospective assessment of toxicity according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) 4.0 criteria according to the C677T and A1298C polymorphisms

Time frame: From treatment initiation to detected toxicity during treatment with any fluoropyrimidine alone or in combination with oxaliplatin, irinotecan or any biological treatment as first line therapy of colorectal metastatic cancer (up to 24 months)