A Tumor That Doesn't Follow the Rules
Desmoid tumors are strange. They don't spread to other organs. They aren't technically cancerous in the classic sense. But they grow into the surrounding tissue — muscles, nerves, blood vessels — and they can be incredibly difficult to remove.
What makes them particularly confusing: they sometimes grow after surgery. Some doctors have worried that cutting into them actually makes them worse.
Who Gets Desmoid Tumors
Desmoid tumors are rare — estimated to affect about 2-4 people per million each year. They tend to appear in young adults, often in the abdomen, chest wall, or limbs.
Some cases are linked to a genetic condition called familial adenomatous polyposis (FAP). Others develop after physical trauma or surgery. The unpredictability of these tumors — some stay stable for years, others grow rapidly — makes treatment decisions difficult.
The Long-Standing Debate
For decades, surgery was the go-to treatment. Remove the tumor, solve the problem.
But a shift happened when doctors noticed that desmoid tumors sometimes grew back more aggressively after surgery — and occasionally, tumors that were left alone stabilized or even shrank on their own.
This led many centers to shift toward active surveillance: monitoring the tumor closely with imaging and only intervening if it began growing significantly.
But here's the twist: this study suggests the fear of surgery triggering growth may have been overstated.
What Drives Desmoid Tumor Growth
The exact biology of desmoid tumors is still being worked out. They arise from fibroblasts — cells that normally help build connective tissue. Think of them as the body's construction crew going rogue and building walls in the wrong places.
Hormonal signals, trauma, and the protein beta-catenin (part of a key cellular pathway) all appear to play roles. Surgery creates inflammation and triggers healing signals — which some researchers believe could stimulate tumor regrowth. This study challenges how significant that mechanism actually is in practice.
Researchers reviewed records from 76 patients with desmoid tumors treated at the National Cancer Centre Singapore between 1999 and 2023. Nineteen were managed with active surveillance. Fifty-seven underwent surgical resection — with varying degrees of completeness. Tumor behavior was assessed by imaging at one year.
At one year, progression rates were nearly identical between the two groups: 26.3% in the surveillance group, 22.8% in the surgical group. Surgery did not appear to make tumors grow faster than waiting.
Long-term outcomes, however, favored complete surgical removal. Among patients who had R0 resection (complete removal with clear margins), no cases showed further progression long-term. Tumors that initially recurred after complete removal either stabilized or regressed without additional treatment.
Here's Where It Gets Interesting
The similarity in one-year progression rates doesn't mean surgery and surveillance are equivalent choices — it means the decision can be made on its own merits for each patient.
For someone whose tumor is near a vital structure, or who is experiencing symptoms, surgery may offer the better long-term outcome. For someone with a small, stable tumor in a less dangerous location, surveillance is a reasonable choice that avoids surgical risk.
What the Data Tells Experts
The authors argue that surgery should no longer carry a blanket warning of "may accelerate growth." That fear, while understandable, may have pushed some patients toward prolonged watchful waiting when surgery could have offered durable control.
At the same time, incomplete removal — where some tumor tissue remains — showed higher one-year progression rates, suggesting that partial surgery may carry more risk than either full removal or no surgery at all.
If you or someone you know has been diagnosed with a desmoid tumor, this research offers reassurance that surgery doesn't automatically make things worse. It also reinforces that the choice between surgery and surveillance should be made with a specialist who has experience with these tumors — not as a one-size-fits-all protocol.
Asking your care team about the completeness of possible resection — whether they expect R0, R1, or R2 — is a meaningful question that this data supports.
The study was retrospective and included only 76 patients across 24 years at a single center. The groups were not randomized, meaning patients selected for surgery or surveillance weren't necessarily comparable. The small numbers make it difficult to draw conclusions about specific subgroups.
What Comes Next
Larger prospective studies and ideally randomized trials are needed to confirm these findings. International desmoid tumor registries are being developed that may eventually provide the kind of multicenter data needed to give stronger, personalized guidance on when to operate and when to wait.