Cancer diagnostics are undergoing a revolution. No longer limited to tissue samples, clinicians are now reading real-time signals from blood to understand how tumors evolve and how best to fight them.

In this episode of Rubin On Point, Dan Rubin, ND, FABNO talks with Brandon S. Guida, PhD, Mc.S, MS, MB(ASCP)—a translational and interdisciplinary scientist with more than two decades of experience spanning clinical diagnostics, pharma, biotech, and academia.

Dr. Guida's career bridges molecular and cellular biology, microbiology, neurogenomics, microscopy, bioinformatics, and oncology—giving him a rare ability to translate complex data into meaningful, real-world insights.

For the past six years, he’s focused on scientific communication and clinical education, helping establish regenerative medicine and precision oncology as standards of care. Now, as a Medical Science Liaison in oncology diagnostics, he partners with clinicians to integrate next-generation liquid biopsy technology into the cancer care continuum.

Together, they pull back the curtain on where precision oncology is headed:

* cfDNA vs. ctDNA — what they really mean and how blood can show cancer’s presence and evolution

* Tumor fraction — a near real-time “cancer signal” that can change before imaging

* MRD (Molecular Residual Disease) — predicting recurrence and guiding therapy earlier

* ESR1 resistance — catching endocrine therapy resistance in breast cancer before scans show progression

* Dark DNA — why most of our genome isn’t “junk” and how unlocking it could shift cancer care

* PCR vs. NGS — where each fits, and how sequencing depth and breadth influence what we see

* VUS & TMB — interpreting complexity, mutational burden, and immunotherapy sensitivity

* The next horizon: AI, bioinformatics, and truly individualized (“N-of-1”) cancer care

If you’ve ever looked at a genetic test result and wondered what it really means, this conversation is your roadmap to the fast-changing world of cancer diagnostics and resilience.

Chapters
00:00 Welcome & resilience


01:10 Genetics vs. genomics and the “dark genome”


08:18 What a liquid biopsy really measures


10:00 PCR vs. NGS explained
20:00 cfDNA vs. ctDNA; timing after chemo or radiation


33:07 MRD — molecular recurrence before imaging


36:07 ESR1 monitoring & therapy pivots


43:27 VUS, TMB & immune responsiveness


47:14 AI, bioinformatics & the N-of-1 future

Educational only. Not medical advice. Always consult your care team.