Stage 4 Cancer: I wish I knew about these tests sooner.
These are the tests our founder, Smilo, went through on his journey. Everyone’s cancer is different, so use this as a starting point for a conversation with your care team.
At a glance
| Test | What it does | Sample | Approx. cost |
|---|---|---|---|
| 1. Tumor genomic sequencing | Looks at the biology of your cancer so you know how to target it | Tumor tissue or blood | Usually covered |
| 2. Germline testing | Finds inherited cancer-related genes | Blood or saliva | Often covered · ~$250–400 |
| 3. ctDNA monitoring | Tracks tumor DNA in your blood; can catch recurrence early | Blood | Varies by plan |
| 4. Gut microbiome | Shows what may be missing or imbalanced in your gut | Stool | ~$200–250 |
| 5. Circulating tumor cells | Tests your tumor cells against actual treatments like chemo | Blood | ~$1,500–3,500 |
| 6. Wellness genetics | Shows how your genes may impact your health | Cheek swab | ~$300–400 |
Full details
Cancer care testing
Tumor genomic sequencingFoundation Medicine, Tempus, Caris and others
Looks at the biology inside your cancer so you and your doctors know how to target it. It reads the DNA of your tumor to find the specific mutations and markers driving it, which can point to targeted drugs, immunotherapy, or clinical trials built for your cancer. This is the test that led Mike to his treatment.
- Who
- Advanced or returning cancer
- Sample
- 🩸 Tumor tissue or blood
- How to get it
- Ask your doctor: “Has my tumor had full genomic testing? Can I see the report?”
- Cost
- Usually covered for advanced cancer. List ~$3,000–6,000; labs offer help.
- Learn more
- National Cancer Institute ↗
Germline (inherited) testingInvitae, Myriad, Color and others
Finds inherited cancer-related genes, the ones you were born with, like BRCA. Knowing this can open up certain treatment options, explain why cancer runs in a family, and tell relatives whether they should get checked too.
- Who
- Anyone, with or without cancer, especially if you were diagnosed young, have relatives with cancer or a known family mutation, or have breast, ovarian, pancreatic, or prostate cancer
- Sample
- 🩸 Blood or 🧪 saliva
- How to get it
- Ask your care team or a genetic counselor. Some tests can also be ordered online.
- Cost
- Often covered when guidelines apply. Self-pay ~$250–400.
- Learn more
- National Cancer Institute ↗
ctDNA monitoringSignatera by Natera
Tracks tumor DNA in your blood over time. It can show whether treatment is working and can catch signs of recurrence early, sometimes months before a scan would. It adds to scans rather than replacing them.
- Who
- In treatment, or in remission and watching for recurrence
- Sample
- 🩸 Blood
- How to get it
- Ask your doctor: “Could ctDNA monitoring help track how I’m doing?”
- Cost
- Covered by Medicare for several cancers; private insurance varies. Natera offers financial help.
- Learn more
- Natera ↗
Additional testing Not a substitute for standard cancer testing
Gut microbiome testTiny Health — the one Mike used; others offer this too
Shows what may be missing or imbalanced in your gut. A healthy gut is linked in early research to better immunotherapy response and fewer stomach side effects, so this can be a starting point for diet and probiotic changes. The science is promising but still young.
- Who
- Anyone, with or without cancer, especially if you are on immunotherapy or curious about gut health
- Sample
- 🏠 Stool, at home
- How to get it
- Order from their website.
- Cost
- ~$200–250. Not covered.
- Learn more
- Tiny Health ↗
Circulating tumor cell testRGCC — the one Mike used
Tests your tumor cells against actual treatments like chemo. Cancer cells are pulled from a blood sample and exposed in a lab to different drugs and, on some panels, natural compounds, to see which ones they respond to. This is an additional data point, not standard oncology testing, and shouldn’t replace your care team’s treatment decisions.
- Who
- Anyone with cancer who wants to explore additional options
- Sample
- 🩸 Blood
- How to get it
- Through an integrative or functional medicine provider.
- Cost
- ~$1,500–3,500 depending on panel. Not covered.
- Note
- Should not replace standard oncology testing or treatment decisions.
- Learn more
- RGCC ↗
Wellness genetic testing3X4 Genetics — the one Mike used; others offer this too
Shows how your genes may impact your health. It looks at inherited variants across areas like methylation (including MTHFR), inflammation, detox, and nutrient needs, and turns them into nutrition and lifestyle suggestions. It’s a wellness tool, not a cancer test, but it helped Mike understand what his body needed alongside treatment.
- Who
- Anyone, with or without cancer
- Sample
- 🏠 Cheek swab, at home
- How to get it
- Order from their website.
- Cost
- ~$300–400. Not covered.
- Learn more
- 3X4 Genetics ↗
One more thing: this list is what helped Mike. There may be other tests that matter a lot for your specific cancer that aren’t here, so always ask your care team what else could be worth checking.
Shared with love by the Smilo Foundation. This is for information only, not medical advice, and hasn’t been reviewed by a doctor. Your care team knows your situation best. Prices are approximate as of September 2026 and can change; coverage depends on your plan.
Golden Rules for Self-Advocacy
Get copies of everything: Keep your own copies of pathology reports, genomic testing, lab work, scans, and other medical records.
Trust your gut. Keep asking questions: You and your family are your strongest advocates. If something doesn’t make sense, ask again.
Get second (and third) opinions: Never feel guilty about consulting another specialist or exploring another cancer center.
We’re In This Together
At The Smilo Foundation, we know firsthand how access to the right information, right testing, and right experts can change everything. Don’t be afraid to ask questions, seek another opinion, explore every avenue, and advocate for your care.
