Podcast Summary for S2E9: No Longer Optional: Genetic Testing for Cancer Patients in 2026

Full episode is available here (in Cantonese).

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1. Introduction: Confronting the Fear of Genetic Testing

• Many cancer patients feel resistant to genetic testing after diagnosis, worrying that discovering a hereditary mutation will burden their children psychologically, and believing that genetic information has no direct bearing on their current treatment.

• Host Yoyo acknowledges this fear fully, but explains that a landmark update to international medical guidelines in 2026 has fundamentally changed the meaning and scope of genetic testing in oncology.

• Yoyo is Hong Kong’s first Australian-certified genetic counsellor with over thirteen years of clinical practice in the city. This episode aims to explain how precision medicine can restore a sense of agency and choice for cancer patients.

2. A Real Patient Story: Ming’s Journey

• Ming, aged fifty, was diagnosed with colorectal cancer. His oncologist recommended genetic testing, but provided little explanation, leaving him unable to understand its practical purpose.

• Ming initially believed genetic testing was only relevant to hereditary risk and the health of his children, and felt it had nothing to do with his own treatment at the time, causing him to hesitate.

• After receiving genetic counselling, Ming proceeded with germline testing. The results revealed that he carried a gene associated with Lynch Syndrome, and that his tumour exhibited a key characteristic known as dMMR (mismatch repair deficiency).

• Armed with this genetic information, his oncologist decided to incorporate the immunotherapy drug Pembrolizumab into his treatment plan — a significant change in therapeutic direction that would not have been possible without the test results, demonstrating the direct impact genetic testing can have on immediate clinical decisions.

3. The 2026 NCCN Guideline Update: From “Optional” to “Essential”

• On 16 June 2026, the National Comprehensive Cancer Network (NCCN) — the world’s most authoritative body on clinical cancer practice guidelines — published a major update that formally changed the standards for cancer genetic testing.

• Previously, doctors would typically assess a patient’s age and family history before recommending genetic testing. Older patients or those without a notable family history of cancer were often never offered it.

• The updated guidelines explicitly recommend that all patients diagnosed with colorectal cancer, endometrial cancer, or gastric cancer, as well as those whose tumours exhibit dMMR features, should undergo germline testing — regardless of age or family history.

• There are two distinct types of cancer genetic testing: somatic testing examines acquired genetic changes within the tumour itself and is not heritable. Germline testing examines the inherited genetic code present in every cell of the body, which may be passed on to future generations. The NCCN update calls for the adoption of the latter.

• The driving force behind this update is the finding that Lynch Syndrome is far more prevalent among patients with these cancers than previously estimated. Crucially, targeted treatments now exist that make the test results directly actionable in a clinical setting.

4. The Dual Role of Genetic Testing: Diagnostic Tool and Prevention Tool

• As a diagnostic tool: Genetic testing helps doctors identify the most precise treatment approach for each patient. In the era of precision medicine, the genetic profile of a tumour directly determines which therapies are most effective. Tumours with dMMR features respond significantly well to immunotherapy, but this can only be confirmed and acted upon through testing.

• As a prevention tool: Confirming the presence of Lynch Syndrome-related gene variants allows patients and their medical team to establish a more proactive long-term monitoring plan, as the syndrome increases the risk of multiple cancer types. This genetic information serves as both a treatment guide for the present and a health roadmap for the future.

• Implications for family members: Carrying a hereditary gene variant means that close relatives may harbour the same mutation. Being aware of this is not bad news, but rather an opportunity. Family members can begin targeted screening from a younger age, intercepting potential problems before they develop into cancer.

• The updated NCCN guidelines also recommend the use of multi-gene panel testing, scanning over a dozen key genes in a single test — including Lynch Syndrome-related genes, BRCA1/2, and TP53 — providing doctors with a comprehensive map of actionable targets rather than a single-point investigation.

5. On-the-Ground Challenges in Hong Kong: Three Barriers to Overcome

• The first barrier — limited accessibility of testing: Guideline updates do not automatically translate into immediate changes in clinical practice. Some hospitals only perform somatic testing on tumour tissue and may not proactively arrange the deeper germline testing now recommended. Yoyo encourages patients to ask their oncologist directly whether germline testing is appropriate for them, and to request a referral to a genetics specialist if needed.

• The second barrier — difficulty interpreting reports: Genetic reports are considerably more complex than standard blood test results, involving nuanced interpretations of gene variants. Terms such as VUS (Variant of Uncertain Significance) can cause significant anxiety if left unexplained, potentially leading patients to make unnecessary or ill-informed decisions about their care.

• The third barrier — integrating findings into treatment decisions: Receiving a report is only the first step. The greater challenge lies in translating genetic findings into concrete clinical actions — such as adjusting treatment protocols, identifying suitable clinical trials, and advising family members on next steps. This is precisely why the role of a genetic counsellor has become more indispensable than ever in this new era of oncology.

6. The Role of the Genetic Counsellor: Accompanying the Entire Journey

• A genetic counsellor’s involvement begins well before a patient receives their report. It starts from the moment a patient considers whether to undergo testing. The counsellor helps assess the appropriateness of testing, prepares the patient psychologically for potential outcomes, and ensures that any decision made is a truly informed one.

• Once the report is received, the genetic counsellor walks through the findings with the patient line by line, explaining the clinical implications of each variant, and helping to identify any targeted therapies or ongoing clinical trials that may be relevant based on the patient’s genetic profile.

• Throughout the treatment journey, the genetic counsellor acts as a bridge between the patient and the oncology team, ensuring that genetic information is genuinely integrated into the treatment plan rather than left as an uninterpreted document.

• Yoyo emphasises that when facing a genetic report, patients need more than professional explanation. They also need a safe space to process the emotions that the results may bring, whether that is fear, relief, or deeper uncertainty. All of these responses are natural and deserve to be handled with care.

7. Closing Remarks: Yoyo’s Perspective and Call to Action

• The 2026 NCCN guideline update formally marks a turning point: genetic testing has evolved from a tool for predicting future risk into a core instrument for shaping present-day treatment decisions. For patients with colorectal, endometrial, or gastric cancer, germline testing is now a right — one that can meaningfully improve their chances of survival.

• Yoyo reflects that fear is most often rooted in the unknown, and that genetic testing is precisely the act of using what can be known now to confront what is uncertain. In her view, what is hardest to treat is never the genetic change itself, but rather silence and a lack of information.

• Listeners who hold a genetic report they cannot understand, are considering whether to proceed with a doctor-recommended test, or are seeking professional guidance on behalf of a family member battling cancer, are encouraged to book a consultation with Yoyo. It is available to anyone, wherever they may be.

GENE TALKS Podcast Disclaimer

The content of this podcast is provided for general educational and informational purposes only and does not constitute medical advice, diagnosis, or treatment of any kind.

If you have questions about your personal health, genetic test results, or medical decisions, you should consult a qualified healthcare or genetics professional.

Any cases, experiences, or opinions mentioned in this program reflect the personal views of the host, and do not represent the positions of any medical institutions or professional organisations.

While GENE TALKS and its host endeavor to provide accurate and reliable information, they are not responsible for any consequences arising from the use or interpretation of the content.

Our mission: to help you understand genetics — and yourself — not to replace professional judgment.