Consultant, Molecular Haematology & Oncology, Fortis Memorial Research Institute, Gurugram
Part 3 of 9 in Genomics Revolution in Cancer
How Genomic Sequencing Changed Precision Medicine in Stage 4 Lung Cancer
January 19, 2025
A Diagnosis That Used to Mean Months, Not Years
Before 2007, a stage 4 lung cancer diagnosis carried a fixed, grim prognosis: survival of roughly six months. Only about 30 percent of patients even opted for chemotherapy at the time, and even among that minority, survival was typically limited to around a year and a half.
Genome sequencing changed that calculation. The US FDA has approved targeted oral medicines for at least ten specific gene mutations found in lung cancer, and a patient whose tumour carries one of those mutations and receives the matching drug now has a median survival of 36 months, meaning average survival runs well past 50 months. Dr. Nathany calls this 'bullseye therapy': once sequencing identifies the exact gene or molecule driving a tumour, treatment is aimed directly at it, rather than at the cancer in general.
Lung Cancer Is Furthest Along
Genomic sequencing to select targeted treatment is most established in lung cancer, where it is already recommended and proven in clinical practice. The same degree of genomic guidance is still being worked out for many other cancers, where it remains under active research rather than routine, guideline-based care.
This guide is based on a live Jivo Masterclass: Dr. Shrinidhi Nathany taught doctors across Africa on January 19, 2025.
FROM THE LIVE Q&A
Moderator
What has caused the rise in cancer in the world today?
Dr. Shrinidhi Nathany
What has caused the rise in cancer is multifactorial. Number one is lifestyle. Number two is environmental insults like radiation and the kind of food we eat, and stress. But also underrated and underdiagnosed is genetics, and at least 30% of cancers are genetic, so we need to test to understand those cases.
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Frequently Asked Questions
Can you clarify what CRISPR-Cas9 is?▼
CRISPR-Cas9 is a technology related to gene therapy that lets you edit the gene. CRISPR is gene editing, and the Cas9 technology is what lets us edit the gene, for example the gene causing type 1 diabetes mellitus, and deliver it back to the patient so the disease is cured. That is not yet available in all countries.
What is the most common genetic cancer?▼
The most common genetic cancer, as it's the most commonly tested for, is breast cancer. Breast and ovarian cancer has a syndrome called hereditary breast and ovarian cancer syndrome, and that is the most common because it is right now the most tested for. However, there are many more cancers which can be inherited.
Can molecular genomics help in preventing aging?▼
That is the most in-thing right now, which is longevity testing, which can tell you your actual biological age. Supposing you are 30 years of age by your date of birth, but because of stress your body may actually be 40 years old biologically. You can prevent that: we can first study why your body is aging faster, and then you can modify your lifestyle based on the genetics, what you should eat and what you should not eat and what kind of therapy you should take, and it gives you a lot of a personalised report.
Can you clarify more about gene therapy?▼
For example, sickle cell anaemia is caused by a point mutation where only one letter in the genome is changing. So what we can do is if A is becoming B, we make the B back to A and edit that gene, and deliver it through an IV cannula in the form of a solution. That is what is going to get integrated into the patient, and the disease can be cured. That is what gene therapy is.
Can we do genomic modifications to prevent cancer?▼
Well, not yet. What we can do is, supposing somebody in my family got cancer, I can get my genes tested so I know whether I am at risk of getting that cancer, and then I can try to catch it early, because once you're at a last stage it becomes difficult to cure. If you catch it early you can still cure the cancer.
How has genomic sequencing changed survival in stage 4 lung cancer?▼
Before 2007, stage 4 lung cancer carried a typical survival of about six months. With genomic sequencing identifying a targetable mutation and matching oral medicine, median survival has improved to 36 months, with average survival running past 50 months.
What is 'bullseye therapy'?▼
A term for treatment aimed directly at the specific gene or molecule that genomic sequencing identifies as driving a patient's tumour, rather than treating the cancer generically.
How many lung cancer gene mutations have FDA-approved targeted drugs?▼
At least ten, as of the guidelines Dr. Nathany referenced.
In This Series: Genomics Revolution in Cancer
- 1.Genomics Revolution in Cancer
- 2.Germline Versus Somatic Testing: The Two Pillars of Genomic Testing
- 3.How Genomic Sequencing Changed Precision Medicine in Stage 4 Lung Cancer
- 4.Hereditary Cancer Risk: BRCA, HBOC Syndrome and the Case for Family Testing
- 5.Pharmacogenomics: How Genes Shape Drug Response and Side Effects
- 6.Liquid Biopsy for Cancer Screening: What's Proven and What's Still Under Research
- 7.Inside Next Generation Sequencing: How Genomic Testing Actually Works
- 8.Gene Therapy and Genome Editing: From Sickle Cell Anaemia to CRISPR
- 9.Genomics Beyond Cancer: Cardiology, Neurology and Pre-Marital Screening