What Biomarker Testing You Should Request Before a Biopsy or Tumor Surgery
When you’re preparing for a biopsy or cancer surgery for breast cancer, colon cancer, colorectal cancer, brain cancer, or any other type, one of the most important cancer treatment decisions happens before the procedure even begins: requesting biomarker testing. Genomic testing, tumor DNA sequencing, PD-L1 staining, and biomarker testing determine which chemotherapy, targeted cancer therapy, and cancer immunotherapy are likely to work for your tumor. Without this information, oncology teams are often forced to guess.
Tumors evolve over time. If your cancer has recurred, new genetic testing is especially important because the cancer biology may now be very different from when it was first diagnosed.
Genomic Testing and Tumor DNA Sequencing
The first essential test is genomic testing, sometimes called tumor DNA sequencing or genetic testing. This looks for mutations inside the tumor that control how the cancer grows and responds to treatment.
These mutations don’t just guide targeted therapy. They also affect how chemotherapy works. Some mutations make certain chemo drugs ineffective, while others make tumors far more sensitive to DNA-damaging agents. Without tumor DNA sequencing, doctors may choose drugs that are much less effective for your cancer.
When asking for genomic testing, always choose the broadest panel available. If one test covers 50 genes and another covers 100, pick the larger one. Even if you have lung cancer, a mutation commonly seen in melanoma or colon cancer may still guide treatment. The more mutations tested, the more options your care team has.
PD-L1 and Cancer Immunotherapy
The second critical biomarker is PD-L1. This test determines whether your tumor is likely to respond to immune checkpoint inhibitors, a powerful form of cancer immunotherapy.
PD-L1 staining should be done on all major tumor samples whenever possible. Without it, patients may miss out on life-changing immunotherapy options that work through the immune system.
Why Repeat Biomarker Testing Matters
If a tumor comes back, it should be tested again. Cancer cells can mutate rapidly, and treatments themselves apply selective pressure that changes tumor biology. A recurrence can have a very different genomic profile, which may open new treatment doors—or close old ones.
Cancer Surgery vs. Tumor Destruction
Traditional cancer surgery removes the tumor entirely. Newer approaches such as histotripsy, cryoablation, and radiofrequency ablation destroy the tumor in place. When cancer cells are killed but left inside the body, they release proteins that help the immune system recognize and attack remaining disease.
A separate prior biopsy can still provide material for biomarker testing, while leaving immune-stimulating tumor debris behind. This can strengthen cancer immunotherapy and your long-term immune control of cancer.
How Biomarker Testing Expands Your Options
Patients are often told they have only one treatment path. In reality, genomic testing and biomarker analysis can reveal dozens of anticancer drug options, including off-label therapies, targeted therapy, and optimized chemo combinations.
Understanding what biomarker testing shows—and having it explained clearly—can dramatically change how cancer treatment decisions are made.
If you’re facing a biopsy, or tumor removal, especially after recurrence, make sure genomic testing and PD-L1 staining are part of your plan. The information they provide can optimize every step that follows.
Disclaimer: This content is for educational purposes only and is not medical advice. It does not replace guidance from your healthcare provider. Cancer and treatment decisions are highly individual—always consult your physician or qualified healthcare professional regarding your specific situation.
A full disclaimer is available Terms and Conditions.