CPT® Code 81518

Oncology (breast), mRNA, gene expression profiling by real-time RT-PCR of 11 genes (7 content and 4 housekeeping), utilizing formalin-fixed paraffin-embedded tissue, algorithms reported as percentage risk for metastatic recurrence and likelihood of benefit from extended endocrine therapy

The CPT® Code 81518 pertains to a specific molecular genetic test utilized in oncology, particularly for breast cancer. This test involves the analysis of messenger RNA (mRNA) through a process known as real-time reverse transcription polymerase chain reaction (RT-PCR). The assay evaluates the expression of 11 genes, which includes 7 content genes that are directly related to cancer progression and 4 housekeeping genes that serve as controls to ensure the accuracy of the test results. The tissue sample used for this analysis is formalin-fixed paraffin-embedded (FFPE), which is a common method for preserving biological tissues for examination. The primary purpose of this test is to generate an algorithm that provides a percentage risk score for metastatic recurrence, which indicates the likelihood that the cancer will return after treatment. Additionally, the test assesses the potential benefit of extended endocrine therapy, which is a treatment aimed at hormone receptor-positive breast cancer. This test is particularly relevant for patients with Stage I or II breast tumors that are estrogen receptor positive (ER+) and human epidermal growth factor receptor 2 negative (HER2-), especially in cases where there is no lymph node involvement or only a limited number of lymph nodes are affected. The results of the mRNA gene expression profiling are critical for clinicians as they integrate these findings with other clinical factors such as patient age, tumor size, and lymph node status to make informed decisions regarding the continuation or adjustment of endocrine therapy.