Introduction
Papillary thyroid cancer is the most common type of thyroid cancer, and its incidence is increasing by approximately 6% every year. For most patients, the prognosis is good. But good odds on a population level do not always translate into clarity for the individual patient sitting in a clinic, trying to understand what their diagnosis means and what should happen next.
As we have explored throughout this blog series, precision oncology is changing how we approach these moments. Rather than making treatment decisions based solely on what a tumour looks like, we can now look at what it is actually doing at a biological level. For papillary thyroid cancer, that is exactly what Thyroid GuidePx® was designed to do.
The Challenge With Papillary Thyroid Cancer
Papillary thyroid cancer is not one uniform disease. Some tumours are slow-growing and pose very little long-term risk. Others are more aggressive and more likely to return after treatment. The challenge is that these tumours can look very similar on a scan or under a microscope, making it genuinely difficult to know upfront which category a patient falls into.
Current treatment decisions are largely based on traditional clinical factors such as tumour size and whether the cancer has spread to nearby lymph nodes. These factors are useful, but they do not always capture the full biological picture.
This uncertainty plays out in a very real way for patients. Papillary thyroid cancer is widely overtreated. Many patients undergo a total thyroidectomy and receive radioactive iodine when they do not need it. You can read more about these treatment approaches in our previous blog posts on surgical approaches to thyroid cancer and radioactive iodine therapy.
Another common and particularly difficult scenario involves patients who initially have a lobectomy, where only part of the thyroid is removed, and then require a second surgery to remove the rest of the thyroid because high-risk features were only identified in the final pathology after the first operation. Having two surgeries in a short space of time is stressful, physically and emotionally, and in many cases could be avoided with better information upfront.
This is the gap that Thyroid GuidePx® was built to address. Research by Bathe and Stretch published in Technology in Cancer Research and Treatment shows that the current reliance on clinical and pathological factors leads to overtreatment, with more patients undergoing total thyroidectomy than necessary, completion thyroidectomy rates that remain unacceptably high, and radioactive iodine used more frequently than needed. (Bathe and Stretch, 2025)
What Is Thyroid GuidePx®?
Thyroid GuidePx® is a gene expression test developed by Qualisure Diagnostics that analyses the activity of 82 genes within a papillary thyroid cancer tumour. As we explored in our previous article, gene expression testing goes beyond looking at what is present in a tumour and instead measures what the tumour is actually doing at a molecular level.
The 82 genes in the test were identified using a machine learning approach that analysed data from over 500 papillary thyroid cancer patients to find the genes most closely associated with whether a cancer returned after treatment. By analysing the pattern of activity across these genes, Thyroid GuidePx® classifies papillary thyroid cancer into three molecular subtypes, each reflecting a different level of recurrence risk. (Craig et al., Frontiers in Endocrinology, 2023)
The test can be performed on a tumour sample collected either before or during surgery, meaning the information is available at exactly the point when it is most needed.
What the Subtypes Mean for Patients
The three molecular subtypes identified by Thyroid GuidePx® reflect meaningful differences in how a tumour is likely to behave over time.
Patients whose tumours are classified as Type 1 or Type 2 at an early stage have a low risk of recurrence. For these patients, Thyroid GuidePx® provides the biological evidence needed to consider a more conservative treatment approach. That might mean a lobectomy rather than a total thyroidectomy, or in some carefully selected cases, active surveillance rather than surgery at all. It can also mean avoiding radioactive iodine and the side effects that come with it.
Patients whose tumours are classified as Type 3 carry a higher risk of recurrence regardless of tumour size. Knowing this early means that a more proactive treatment plan can be put in place from the start, rather than waiting for signs of recurrence to appear later. Importantly, the research shows that Type 3 tumours carry a high recurrence risk even when they appear small and localised, which is exactly why relying on size and appearance alone can lead clinicians astray.
For patients with small tumours where the treatment pathway is genuinely unclear, this kind of biological insight is particularly valuable. It gives both the patient and their care team a clearer, more confident basis for the decisions ahead.
Validated Across Multiple Patient Populations
The prognostic value of Thyroid GuidePx® has been validated across independent patient cohorts from the United States, Canada, and South Korea, representing over 700 patients in total. In these studies, molecular subtype was found to be a more impactful predictor of recurrence than any single clinical or pathological feature, outperforming the standard risk stratification system used by the American Thyroid Association. (Craig et al., Frontiers in Endocrinology, 2023)
Clinical Recognition
Thyroid GuidePx® is not just a promising new tool. It is one that is increasingly being recognised by the clinical community. In 2025, Thyroid GuidePx® was cited in the American Thyroid Association Guidelines, one of the most authoritative clinical references in thyroid cancer management. This recognition reflects the growing body of evidence supporting the use of molecular classifiers in papillary thyroid cancer and signals that this type of testing is becoming part of how thyroid cancer is managed at the highest levels of clinical practice.
Why This Matters for Patients
A cancer diagnosis is one of the most overwhelming experiences a person can go through. The decisions that follow, about surgery, about further treatment, about how closely to be monitored, can feel just as daunting. Having access to more precise information about your individual tumour does not remove that difficulty, but it does mean those decisions can be made with greater confidence and with a clearer understanding of what the biology is actually telling us.
For patients with low-risk tumours, Thyroid GuidePx® can provide genuine reassurance and a path toward less invasive care. For those with higher-risk tumours, it ensures that the level of treatment matches what the cancer actually requires. Either way, it puts more information in the hands of the people who need it most.
Conclusion
Precision oncology has already transformed treatment decisions in cancers like breast cancer and lung cancer. Thyroid GuidePx® is bringing that same depth of biological insight to papillary thyroid cancer, helping clinicians and patients navigate one of the most common and fastest growing cancer diagnoses with greater clarity, confidence, and care.
If you have been diagnosed with papillary thyroid cancer and want to learn more about Thyroid GuidePx®, you can find more information at qualisuredx.com.