Resistance to Methotrexate in Patients With Acute Lymphoblastic Leukemia in Relapse or Remission

Study Overview
=================
Brief Summary
-----------------
RATIONALE: Studying samples of blood from patients with cancer in the laboratory may help doctors learn more about cancer and the development of drug resistance in patients. PURPOSE: This laboratory study is looking at resistance to methotrexate in patients with acute lymphoblastic leukemia in relapse or remission.

Detailed Description
-----------------
OBJECTIVES: Determine the mechanisms of intrinsic and acquired methotrexate resistance using in vitro assays of matched initial diagnosis, relapsed, and nonrelapsed (control) leukemic blast samples from patients with acute lymphoblastic leukemia in relapse or remission. Determine if the mechanisms of acquired methotrexate resistance are related to dosage or timing of methotrexate administration or other clinical factors in these patients. OUTLINE: Random samples of frozen leukemic blasts from relapsing patients at initial diagnosis and relapse are selected. A corresponding sample from nonrelapsing patients (control) at initial diagnosis is also randomly selected. Reduced folate carrier (RFC) and dehydrofolate reductase (DHFR) expression is measured using a quantitative reverse transcriptase-polymerase chain reaction assay of prepared RNA. DHFR gene amplification is measured by a dot blot analysis of prepared DNA. Results of these assays are used to determine if a particular mechanism of acquired methotrexate resistance is associated with a particular subset of acute lymphoblastic leukemia patients. Data are collected regarding the actual timing and dosage of methotrexate received by each patient and are correlated with the mechanisms of resistance. PROJECTED ACCRUAL: A total of 135 paired samples will be accrued for this study.

Official Title
-----------------
A Study of the Mechanisms of Intrinsic and Acquired Methotrexate Resistance in Acute Lymphocytic Leukemia

Conditions
-----------------
Leukemia

Intervention / Treatment
-----------------
* Genetic: microarray analysis
* Genetic: reverse transcriptase-polymerase chain reaction
* Other: laboratory biomarker analysis


Participation Criteria
=================
Eligibility Criteria
-----------------
DISEASE CHARACTERISTICS: Meets 1 of the following criteria: Acute lymphoblastic leukemia (ALL) in relapse, including all risk groups and leukemia subtypes, with frozen leukemic blast samples stored from the time of initial diagnosis and relapse Non-relapsing ALL (as control) PATIENT CHARACTERISTICS: Not specified PRIOR CONCURRENT THERAPY: Not specified

Ages Eligible for Study
-----------------
Maximum Age: 120 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Genetic: microarray analysis|nan|
|Genetic: reverse transcriptase-polymerase chain reaction|nan|
|Other: laboratory biomarker analysis|nan|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mechanisms of intrinsic and acquired methotrexate resistance |  |  | 
| Correlation of acquired methotrexate resistance with dosage or timing of methotrexate administration |  |  | 
| Correlation of acquired methotrexate resistance with other clinical factors |  |  | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
adult acute lymphoblastic leukemia in remission, childhood acute lymphoblastic leukemia in remission, recurrent adult acute lymphoblastic leukemia, recurrent childhood acute lymphoblastic leukemia