PCR Assessment of the Efficacy of Therapy in Philadelphia Chromosome-Positive Leukemias

Abstract

As discussed in Chapter 31, the PCR has rapidly assumed an important role in the molecular diagnosis of cancer. Neoplastic transformation is accompanied by a series of somatic genetic mutations that culminate in clinical manifestation of the malignant phenotype. Molecular characterization of these neoplasia-associated genetic alterations has led to the identification of DNA (and resultant) RNA sequences that differ between normal and malignant cells. These altered nucleic acid sequences can be detected by PCR either by the use of specific primers that will amplify the mutant, but not the wild-type, sequence, or by the use of allele-specific oligonucleotide hybridization after amplification of the informative sequence. PCR amplification of these somatic mutations also allows the detection of minimal residual disease (MRD), which is defined as malignant cells that are below the standard limits of detection in a patient who has no clinical evidence of residual neoplastic cells.