Diagnostic biopsies do not cause cancer to spread, according to Dr. Mandeep Singh Malhotra, a surgical and molecular oncologist. While a persistent myth suggests that the procedure triggers metastasis, medical evidence confirms that biopsies are safe, essential, and the standard of care for identifying malignancies. The primary danger to patients is the delay in treatment caused by avoiding or postponing the test.
The Origins of the “Biopsy Spreads Cancer” Myth
The fear that cutting into a tumor will cause it to spread is one of the most common misconceptions encountered by oncologists in India, according to Dr. Malhotra, founder of Art of Healing Cancer. This belief often stems from a misunderstanding of a rare scientific phenomenon known as “needle-tract seeding.”
Needle-tract seeding occurs when a few tumor cells are displaced along the path of a biopsy needle. However, Dr. Malhotra clarifies that this is not synonymous with cancer metastasis. A few cells sitting in a needle track do not constitute the systemic spread of disease. Clinical evidence from the American Cancer Society supports this, confirming that biopsies are a standard, safe practice and that the risk of spreading cancer via this procedure is not supported by clinical data.
Did you know?
In many tier-two and tier-three cities in India, patients may wait two to three weeks for biopsy results. Because cancer continues to grow naturally during this interval, patients often mistakenly attribute the progression of their tumor to the biopsy procedure itself, reinforcing the myth through a flawed cause-and-effect observation.
Why Biopsies Are Essential for Precision Medicine
A biopsy provides critical biological data that imaging alone cannot capture. By analyzing a small tissue sample, doctors can determine the specific type of cancer, its level of aggression, and which targeted therapies or immunotherapies are most likely to succeed. This information is the cornerstone of modern precision oncology.
Without an accurate biopsy, oncologists are effectively “treating in the dark,” according to Dr. Malhotra. Even in the rare event that cells are displaced during a biopsy, those cells are typically removed during the subsequent surgical excision of the tumor. Furthermore, the body’s own immune system, along with standard radiotherapy and systemic treatments, is effective at eliminating residual cells.
The High Cost of Treatment Delays
The correlation between early detection and survival rates is well-documented. For instance, oral cancer patients who receive a diagnosis while the disease is still localized have a five-year survival rate of nearly 79%. In contrast, that rate drops to approximately 19% once the cancer spreads to distant organs.
In India, nearly two-thirds of oral cancer patients are diagnosed only after the disease has reached an advanced stage. The irony, experts note, is that while patients avoid the biopsy to prevent the “spread” of cancer, the resulting delay in care is precisely what allows the disease to progress to a more dangerous, advanced, or metastatic stage.
Frequently Asked Questions
Is it possible for a biopsy to cause metastasis?
No. While “needle-tract seeding” is a documented, rare phenomenon involving the movement of a few cells along a needle path, it is not the same as metastasis, which is the spread of cancer through the body to form new tumors. There is no evidence that a routine diagnostic biopsy causes cancer to spread.
Why does the lump seem to grow after a biopsy?
This is typically due to the natural progression of the cancer during the waiting period for test results. Because patients often receive their biopsy report weeks after the procedure, they mistakenly associate the natural growth of the tumor with the biopsy event.
What happens if cells are displaced during a biopsy?
If cells are displaced, they are typically removed during the primary surgery to excise the tumor. Additionally, systemic treatments, radiotherapy, and the body’s immune system are capable of neutralizing these cells.
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