Overview
The 17-Gene Signature, also known as the Oncocyte DX GPS Test, is a multi-gene expression panel developed for prognostic and predictive purposes in cancer management. The document explains (page 2) that this genomic signature is based on transcriptomic profiling and captures the stemness features of cancer cells—particularly in acute myeloid leukemia (AML)– allowing rapid prediction of how well a patient may respond to standard chemotherapy.
It is also a validated tool for prostate cancer, producing a Genomic Prostate Score (GPS) ranging from 0 to 100 (page 3). A higher GPS indicates a more aggressive disease. The panel includes 12 cancer-related genes and 5 reference genes, all of which reflect biological pathways such as proliferation, invasion, metastasis, immune response, androgen signaling, stromal interaction, and cellular organization (pages 3–5).
The test is also used in early-stage breast cancer, ductal carcinoma in situ (DCIS), non-small cell lung cancer, renal cell carcinoma, and other malignancies (page 7). By integrating multiple biological pathways, the 17-Gene Signature provides personalized therapy guidance, improved risk stratification, and enhanced clinical decision-making (page 16).
Symptoms
The 17-Gene Signature is a diagnostic and prognostic tool, not a disease itself; therefore, symptoms refer to clinical scenarios where the test becomes relevant.
1. Symptoms Suggesting Possible Malignancy
Patients who present with symptoms of cancers for which this assay is indicated may need evaluation using the 17-gene test. These include:
- Breast lumps or abnormalities
- Suspicious prostate abnormalities on biopsy
- Constitutional symptoms linked to hematologic malignancies (e.g., fatigue, weight loss)
2. Symptoms Suggesting Disease Progression
Where recurrence or metastasis is suspected (page 12), symptoms may include:
- New or worsening bone pain
- Local recurrence signs (e.g., breast or prostate discomfort)
- Systemic symptoms such as fatigue or unexplained weakness
- Increasing tumor marker levels
3. Symptoms After Initial Treatment
Patients undergoing adjuvant or hormonal therapy may develop:
- Persistent or worsening symptoms
- Clinical signs of treatment resistance
- The 17-Gene Signature helps predict chemotherapy benefit and recurrence risk (pages 12–13).
Although the test does not diagnose symptoms directly, it is used when these clinical pictures emerge.
Causes
“Causes” refer to the underlying biological mechanisms and clinical factors that lead to the need for a 17-gene molecular signature.
1. Tumor Heterogeneity
Different cancers express genes differently. Single-gene markers are insufficient because tumors are biologically diverse. The 17-Gene Signature captures this heterogeneity (pages 3 & 7).
2. Need for Accurate Prognosis
Traditional clinical markers are not adequate for predicting recurrence, metastasis, or survival. The genomic panel provides improved prognostication (page 14).
3. Personalized Cancer Therapy Requirements
Chemotherapy decisions depend heavily on gene expression patterns. The test predicts chemotherapy benefit and identifies who may safely avoid overtreatment (pages 12 & 16).
4. Identification of Stem-Cell–Like Properties
In AML, the signature evaluates leukemia stem-cell gene expression to predict chemoresistance (page 2).
5. Post-Surgical Risk Assessment
After lumpectomy, mastectomy, or biopsy, tissue samples are submitted for RNA analysis using RT-PCR (pages 9–10).
Risk Factors
Risk factors relate to patient groups for whom the test is most clinically meaningful.
1. Breast Cancer Patients
Particularly those who are:
- ER-positive, HER2-negative
- Node-negative or have 1–3 positive nodes
- Diagnosed with DCIS requiring recurrence prediction (page 17)
2. Prostate Cancer Patients
Those undergoing biopsy for suspected localized prostate cancer benefit from GPS scoring to determine aggressiveness (page 3).
3. AML Patients
AML patients needing evaluation for stemness-related chemotherapy resistance (page 15).
4. Individuals at Risk of Recurrence
Patients with increasing recurrence risk, as shown in the recurrence score charts (pages 12–13).
5. Patients Requiring Therapy Decision Support
The signature assists in selecting therapy intensity, clinical trial enrollment, and alternative regimens (page 15).
6. Populations With High Biological Variability
Patients whose tumor biology is highly variable and not predictable via traditional markers (page 16).
Prevention
While the test does not prevent cancer, the document highlights ways to prevent misclassification, overtreatment, or undertreatment by using the assay appropriately.
1. Use the Test Within Validated Groups
Ensures accuracy—since interpretation outside validated cancer subtypes is limited (page 19).
2. Combine With Clinical and Imaging Findings
The test is not stand-alone; it must be used alongside imaging and clinical parameters (page 19).
3. Ensure Proper Sample Collection
Tissue must be properly fixed in 10% formalin and transported correctly for RNA extraction (pages 9–10).
4. Apply Scores to Guide Therapy
Low-risk patients can avoid unnecessary chemotherapy, while high-risk patients receive intensified treatment plans (pages 12 & 16).
5. Avoid Over-Reliance on Single Biomarkers
The 17-gene panel prevents inaccurate decision-making that often results from interpreting isolated genes (page 16).
6. Adequate Validation & Platform Use
Use validated platforms to prevent errors due to technological limitations (page 19).
