The short answer
Depth of invasion in millimetres drives the operation. Stage IA is a tumor 2 cm or smaller invading 1 mm or less, and for very shallow disease NCI says a wide excision with a 1 cm margin may be done without touching the lymph nodes.
Ask for the depth of invasion in millimetres. Stage IA means a tumor 2 cm or smaller with invasion of 1 mm or less. Anything larger, or deeper than 1 mm, is stage IB.
Radical local excision, aiming at roughly a 1 cm rim of normal tissue, has generally replaced removing the whole vulva for tumors confined to the vulva or perineum; the margin the pathologist measures is what counts.
One-sided groin surgery may fit a small, shallow stage I lesion lying well to one side, with no cancer in the small blood or lymph channels and normal nodes; midline involvement means both groins are checked.
In a study of 403 women, long-term swelling was 1.9 percent after sentinel biopsy alone against 25.2 percent after full groin dissection, and groin recurrence after a negative sentinel biopsy was 3 percent at two years.
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The full explanation.
One millimetre decides a lot
Ask for the depth of invasion on your biopsy, measured in millimetres. It is a small number that changes the operation.
NCI's staging uses it directly. Stage IA means a tumor 2 cm or smaller with invasion of 1 mm or less. Anything larger, or deeper than 1 mm, is stage IB.
For very shallow stage I disease, under 1 mm and without severe skin changes around it, NCI says a wide excision with a 1 cm margin may be done without touching the lymph nodes.
How much skin has to go
Surgery here has become smaller over time. NCI says the trend since the 1980s has been toward more limited operations, often paired with radiation to reduce harm.
For tumors confined to the vulva or perineum, radical local excision has generally replaced removing the whole vulva. Surgeons have long aimed to take about 1 cm of normal tissue around the tumour. That is a working target, not a fixed rule. What the pathologist sees under the microscope counts for more than what was measured in theatre, and the margin bends around the clitoris, the urethra and the anal sphincter.
Ask what margin your surgeon needs. Ask what sits within that margin: the clitoris, the urethra, the anal sphincter.
Checking one groin or both
For a stage I tumor sitting well to one side, without diffuse severe skin changes, and with normal-feeling nodes, NCI describes removing the nodes on that side only.
NCI sets conditions on who fits that. The lesion should be 2 cm or smaller across, with 5 mm or less invasion, no cancer in the small blood or lymph channels, and nodes that feel normal. Ask whether your report meets all four.
Ask where your tumor sits relative to the middle. That position is what decides one groin or two.
The case for a sentinel node biopsy
NCI reports a study of 403 women with vulvar squamous cancers under 4 cm and normal-feeling groin nodes. Cancer was found in the sentinel nodes in 26 percent, and those women went on to full groin surgery.
The comparison of harms is stark. Wound breakdown was 11.7 percent after sentinel biopsy alone, against 34 percent after full groin dissection. Cellulitis was 4.5 against 21.3 percent. Long-term swelling was 1.9 against 25.2 percent. Hospital stay averaged 8.4 days against 13.7.
Groin recurrence after a negative sentinel biopsy was 3 percent at two years. NCI adds a condition: this works when the surgeon does the procedure often.
Size and normal-feeling nodes are not the whole of it. Mapping is generally offered for a single invasive squamous tumour, deeper than 1 mm, under 4 cm, with no node looking suspicious on exam or on a scan, and where the vulva has not already had major surgery. Earlier surgery can reroute the drainage and spoil the map. More than one separate invasive tumour, a suspicious node, or some other cell types all point to full groin dissection instead. Ask which of these fit you, and how often the centre does the mapping.
When radiation comes before surgery
For larger tumors, NCI lists radiation or chemoradiation followed by surgery among the options for stages III and IVA.
It is honest about the evidence. A review of using this to avoid huge operations found no randomized trials, only five smaller studies using four different schedules.
Ask whether shrinking the tumor first could spare you a bigger operation.
Questions to bring to the surgeon
- What is the depth of invasion on my biopsy?
- Does that mean my groin nodes have to be checked?
- Can I have a sentinel node biopsy instead of full groin surgery?
- How often does my surgeon do that procedure?
- Where is my tumor relative to the midline?
- What margin do you need, and what falls inside it?
- Would radiation before surgery mean a smaller operation?
Related pages
Cancer Staging and Biomarker Testing explain the terms used in a vulvar cancer treatment discussion. Clinical Trial vs Standard Treatment, Palliative Care, and Questions to Ask Your Doctor help you prepare for the vulvar cancer appointment itself.
Where this comes from
These questions were drawn from current NCI guidance for vulvar cancer. The staging cut-offs, the sentinel node figures and the surgical criteria above come from the health professional version:
Words to know
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Common questions
What does the depth of invasion change?
It sets the stage and decides whether your groin nodes are checked. Under 1 mm, without severe skin changes around it, NCI says a wide excision with a 1 cm margin may be enough on its own.
Can I have a sentinel node biopsy instead of full groin surgery?
Often, if the tumor is under 4 cm and your groin nodes feel normal. NCI adds one condition: it works when the surgeon does the procedure often. Ask yours how many they do.
Does the position of my tumor decide one groin or two?
Largely. Vulvar lymph drainage follows the midline. A small tumour lying well to one side, with normal nodes, may be mapped or cleared on that side alone. Anything at or crossing the midline needs both groins checked. It is a specialist mapping decision, and it can change once the sentinel nodes are read.
Questions to ask your doctor
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Sources last checked: 2026-08-11 what this meansLast updated: 2026-08-19Next planned review: 2027-07-30
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Editorial review complete — This page completed Cancer Explained's editorial checks (sources, safety, plain language, duplication). It has not been reviewed by a physician or other healthcare professional.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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