Removing lymph nodes during cancer surgery has saved countless lives in many tumour types. Yet recent research is challenging parts of this long-standing practice.
Author
- Justin Stebbing
Professor of Biomedical Sciences, Anglia Ruskin University
Imagine your body's immune defences as a city, and lymph nodes as the hubs where police and firefighters gather fresh intel to launch their attack on criminals. What happens if you remove too many of these hubs? This is a new question at the centre of modern cancer surgery.
When surgeons remove lymph nodes, it's usually for two reasons: to find out whether cancer has spread, and to prevent further spread to other organs. For decades, this approach represented the best standard of care.
If a tumour escapes its original site, cancer cells often travel through lymph vessels and settle in the nearest lymph nodes, which act as biological filters. Detecting cancer cells in lymph nodes signals that a patient's disease may be more likely to return after treatment.
Removing these nodes allows doctors to "stage" the disease accurately, and potentially increase the chances of eradicating all tumour cells - while also telling oncologists like me to treat the cancer more aggressively.
But lymph nodes are not just passive waystations. They play an active role in the body's immune response , acting as meeting points for immune cells to share information about cancer. Recent scientific discoveries have led researchers to rethink how crucial these hubs are for sparking powerful, lasting immune reactions .
One of the newest studies shows lymph nodes help maintain a special type of immune cell called "CD8 positive T cells", which can destroy cancer cells. These immune cells are primed and kept ready to act by the environment inside the lymph nodes.
Without these hubs, the body's anti-cancer immune response, especially during immunotherapy treatment , may be weaker than previously imagined. The research shows how the specific cells in the lymph nodes make an initial anti-cancer burst of activity. However, this has only been demonstrated in the laboratory, not in humans as yet.
Removing lymph nodes is not without drawbacks. Patients can experience swelling ( lymphoedema ), increased risk of infection in the affected limb, and sometimes chronic pain or mobility problems . There's also concern that removing lymph nodes, while reducing short-term risks of cancer spread, might inadvertently weaken the body's long-term immune defences - especially as modern treatments increasingly rely on the patient's natural immunity. This is in line with the new study findings.
Why do surgeons still remove lymph nodes, then?
For many types of solid tumour, the risk of metastatic spread remains high, and lymph node involvement is one of the best predictors of cancer recurrence.
Lymph node removal also provides vital information for choosing the most effective post-surgical treatments. In breast cancer, doctors often use a "sentinel node biopsy" . This means removing only the first lymph node that fluid from the tumour drains into. Checking just this sentinel node helps doctors see if the cancer has spread, while reducing the number of nodes removed and lowering the risk of side-effects.
Medical researchers are learning more about how lymph nodes work during long-term illnesses. The new study shows that lymph nodes aren't just passive filters; they're active training grounds where special immune cells grow, multiply and become powerful fighters. This is especially important during treatments that boost the immune system, such as checkpoint blockade treatments which are now used for many types of cancer .
These results suggest that taking out lymph nodes doesn't just block cancer's spread; it also removes important hubs where the immune system monitors the body and gets reactivated to fight disease.
Over the last decade, hospitals have adopted gentler, more targeted lymph node surgeries. Instead of removing all the nodes in a region, the focus is now on minimising disruption: taking only the nodes most likely to harbour cancer.
This approach reduces complications for patients and may help keep their immunity strong. Some patients with early-stage cancers may even avoid node removal altogether, instead relying on imaging and biopsies to monitor for spread.
For those worried about the consequences of major lymph node removal, emerging therapies offer hope. Immunotherapy drugs, targeted treatments and even cancer vaccines are being developed that can "re-educate" the immune system, even if some lymph nodes have been lost.
Still, there is growing evidence that patients do best when at least some hubs remain - preserving the body's ability to mount and sustain a defence against lingering cancer cells.
In the future, cancer surgery may become even more personalised . By mapping the activity inside lymph nodes - tracking which ones are essential for immune function and which are most likely to seed new tumours - doctors can tailor surgery so each patient gets maximum benefit with minimum harm.
The recent discoveries challenge surgeons and oncologists to weigh every decision carefully: not just for what is removed today, but for the immunity and future defences left behind.
Is removing lymph nodes in cancer surgery a bad idea? The answer is complex. For many patients, it's still a good idea and can be lifesaving. But new science teaches us that lymph nodes are more than just staging posts; they may be indispensable for long-term immune protection. The future promises smarter, more strategic surgery, keeping more of the body's natural defence system intact while targeting cancer with precision.
Justin Stebbing does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
