LIMITATIONS OF
GENOMIC TESTING
Understanding what the test cannot do is part of using what it can do correctly. The limitations do not cancel the clinical value of NGS -- they define when results should be interpreted and when additional testing is warranted.
Specific Limitations Patients Should Understand
These limitations apply to every comprehensive genomic profiling report to varying degrees. Understanding them is part of interpreting results responsibly.
Detection Method Gaps
Standard DNA-based NGS panels are excellent at finding point mutations and small insertions/deletions. They are less reliable for complex structural rearrangements and some gene fusions involving intronic breakpoints. ALK and ROS1 fusions in lung cancer are sometimes better detected by RNA sequencing or FISH than by DNA panels alone.
Tumour Heterogeneity
A biopsy samples one region of one tumour at one point in time. Cancer is not genetically uniform. Different regions can carry different mutations. Metastatic sites can differ from the primary. A single biopsy gives one perspective on a heterogeneous molecular landscape.
The Actionable Gap
Comprehensive NGS identifies far more alterations than currently have matched therapies. Most findings fall into the interesting but not yet actionable category. That is the state of the science, not a testing failure.
Liquid Biopsy Sensitivity
ctDNA-based testing detects less than tissue-based testing in several contexts. Low-shedding tumours, small-volume early-stage disease, and brain metastases are settings where ctDNA levels may be insufficient for reliable detection. A negative liquid biopsy result does not mean an alteration is absent.
Frequently Asked Questions
How CancerFax Helps
CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.
We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.
We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.
We support appointment coordination, document submission, translation, and direct communication with international departments.
For international patients, we help with practical coordination — travel planning, hospital admission guidance, and local support.
If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.
From inquiry through to follow-up, our coordinators provide a single point of contact for the family.
CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.
Questions About What Your NGS Results Do and Do Not Tell You?
CancerFax helps patients understand the scope and limitations of their genomic testing and when additional or repeat testing is warranted.
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified oncologist before making treatment decisions.