A New Operating System for Cancer: How Sid Sijbrandij Is Outpacing an Evolving Disease
Going “Founder Mode” — And What Patients Can Do to Take Control of Their Own Care
What do you do when you’re told:
“There’s nothing more we can do”?
That’s the moment Sid Sijbrandij faced after completing standard of care for osteosarcoma—and seeing his cancer return.
In this conversation, Sid shares how that moment forced a shift in thinking: from following a treatment plan to actively building a system to stay ahead of the disease.
Drawing on his experience as Co-Founder of GitLab, Sid applies principles from software development—continuous feedback, iteration, and systems thinking—to cancer care.
🧠 In This Episode
Sid shares how he shifted from following a treatment plan to actively building a strategy to stay ahead of his disease.
We discuss:
- Why he wishes he had focused earlier on tissue preservation and deeper testing
- The limitations of how tumors are typically stored (and why it matters)
- How cancer can be approached as a dynamic, evolving system
- The role of continuous diagnostics, including ctDNA and immune monitoring
- Why most patients don’t have a clear therapeutic plan beyond the next step
- The real-world challenges of accessing your own tissue and data
Sid also walks through how he began exploring combination and off-label therapies, including immunotherapy approaches designed to increase immune system response.
⚙️ Key Insights
More data creates more options
Tissue quality and sequencing can shape future treatment possibilities.
Cancer evolves—and treatment needs to keep up. Static, step-by-step approaches may not match the speed of the disease.
The system isn’t built for this approach. Patients often face barriers around access, time, and medical liability.
Risk looks different in advanced disease. For some patients, the risk of progression may outweigh treatment risks.
AI is changing access to information
What once took months of research can now be explored in hours.
🔬 Looking Ahead
Sid also shares his experience with a personalized mRNA cancer vaccine—a promising but early technology with a favorable safety profile and growing potential as sequencing and AI improve.
🚀 What Patients Can Do
For those who want to take a more active role in their care, Sid suggests:
- Asking about comprehensive testing and sequencing
- Preserving and accessing tumor tissue whenever possible
- Using AI tools to explore treatment options and questions
- Seeking second opinions and broader expertise
- Considering whether additional or combination approaches may be appropriate.
He also emphasizes:
This approach is not for everyone.
It requires time, effort, and a willingness to navigate uncertainty.
🧭 Final Thought
This episode isn’t about rejecting standard of care. It’s about what happens when patients need—or choose—to go further. Sid’s story highlights a shift: from following a plan→ to building a system. And from treating cancer as fixed→ to engaging with it as something that evolves.
Timestamps
00:00 Episode Intro
02:37 Meet Sid Sijbrandij
09:51 What GitLab Teaches Us About Cancer Care
13:54 The Tissue Hostage Problem
18:39 Building a Therapeutic Ladder
24:11 How AI Empowers Patients
31:36 Future of Cancer Care Today
37:45 Closing Thoughts
PATIENT RESOURCE: Sijbrandij Foundation, Future of Cancer Care Today.
A great article about Sid’s Story: https://centuryofbio.com/p/sid
Sid’s personal website with links to all his healthcare information: https://sytse.com/
Even One Ventures (Sid’s Venture Capital company) invests in companies overcoming the barriers of cancer care: https://www.evenone.ventures/
If you found this valuable, LIKE, SUBSCRIBE, and SHARE to help others access anti-cancer strategies.
Facebook: https://www.facebook.com/outperformcancer/
LinkedIn: https://www.linkedin.com/company/outperform-cancer/
Instagram: https://www.instagram.com/marybethgilliam/
