Chapter 8: How Genomic Testing Helps — Simple Patient Stories

Chapter 8: How Genomic Testing Helps — Simple Patient Stories

Realistic scenarios that show how genomic profiling guides treatment decisions. Every cancer journey is unique, but many patients share similar questions:

• “Will this treatment work for me?”
• “Is there a better option?”
• “What if chemotherapy doesn’t help?”
• “Do my genes affect which medicines I get?”

To help you understand how genomic testing fits into real-world care, here are some simple, fictional examples inspired by common clinical situations. They are not meant to represent your case—only to show how genomic information helps doctors choose the right path.

Story 1: Lung Cancer and Finding the “Light Switch” Mutation

Rita, age 56, was diagnosed with lung cancer. Her doctor sent her tumor sample for genomic testing.

• What the test found: An EGFR mutation—a known “driver” mutation.
• What this meant: Instead of starting chemotherapy, her doctor offered a targeted therapy pill designed to switch off the EGFR signal.
• The result: Her treatment was personalized to her tumor’s biology, and she experienced fewer side effects.
• What patients learn: A single mutation can open the door to treatments that are more precise and gentler than chemotherapy, when appropriate.

Story 2: Colon Cancer and the Power of “No Mutation Found”

Arun, age 65, had metastatic colon cancer. His test showed:

• No KRAS mutation (KRAS wildtype)
• What this meant: Even though “no mutation” sounds uneventful, this result was very meaningful. It told the doctor that Arun could receive a targeted therapy called an EGFR inhibitor—a treatment that would not work if KRAS was mutated.
• The result: The absence of a mutation guided the right therapy.
• What patients learn: Sometimes not finding a mutation is exactly the information your doctor needs.

Story 3: Breast Cancer and the Importance of HRD Testing

Meena, age 49, had ovarian-type breast cancer features. Her genomic test included HRD testing.

• What the test found: Her tumor had HRD positivity—meaning the cancer struggled to repair DNA damage.
• What this meant: She became eligible for a PARP inhibitor, a medicine that works especially well when HRD is present.
• What patients learn: HRD is not a “scientific term to ignore.” It’s a signal that certain treatments may work far better.

Story 4: Lung Cancer Progression and the Role of Liquid Biopsy

Farzana, age 58, was doing well on targeted therapy for lung cancer until her scans showed slight progression. Her doctor ordered a liquid biopsy (a simple blood test) to check for new mutations.

• What the test found: A resistance mutation that explained why the earlier drug stopped working.
• What this meant: Her doctor switched her to a different targeted therapy that works specifically against that resistance change.
• What patients learn: Liquid biopsy helps doctors keep up with how your cancer evolves, ensuring you stay on the most effective treatment.

Story 5: Immunotherapy for a Tumor That Looked Invisible

Rahul, age 45, was diagnosed with a stomach cancer that was not responding well to initial chemotherapy.

• What the test found: MSI-High. This meant his cancer was easily recognizable to the immune system once treated with immunotherapy.
• What this meant: Rahul became eligible for immunotherapy—a treatment he hadn’t considered before.
• What patients learn: A simple marker like MSI-H can completely change the treatment plan and offer new hope.

Story 6: When a Small Panel Doesn’t Give the Full Picture

Suma, age 52, initially had a small genomic test (about 40 genes). It did not show any actionable mutations. Her doctor recommended comprehensive genomic profiling.

• What the larger test found: * A gene fusion missed by the smaller panel.
  • A biomarker that made her eligible for immunotherapy.
  • A clinical trial match.
• What patients learn: Sometimes deeper testing reveals crucial information that smaller panels miss—and this can directly impact treatment choices.

What These Stories Teach Us

• Genomic testing personalizes treatment: Two patients with the same cancer may receive completely different therapies based on their tumor’s DNA.
• Sometimes the most important answer is “NO mutation found”: This can guide therapy just as much as finding a mutation.
• Biomarkers like HRD, MSI, TMB, and PD-L1 are powerful clues: They help determine whether targeted therapy or immunotherapy might work.
• Cancer evolves — and testing may be repeated: Liquid biopsy helps doctors stay updated on how the disease is changing.
• Bigger tests often provide bigger answers: Comprehensive and whole-exome tests can uncover options smaller panels miss.

A Final Thought

Your journey is unique, and your cancer is unique. Genomic testing helps your oncologist understand your tumor’s “language” so they can choose treatments that speak directly to it.

Your oncologist is your partner in this process. They use these findings — whether big, small, or even absent — to guide you toward the safest and most effective treatment plan.