What Do "Negative" and "Close" Margins Mean?

This page is for people whose surgery or pathology report describes the margins as negative, close, or positive. It explains what each term means and how it can change your treatment plan.

When a surgeon removes a tumor, they take out the tumor itself. They also take a rim of normal-looking tissue around it, called the margin. A pathologist then examines that rim under a microscope. They check whether cancer cells reach all the way to its outer edge. This tells your team whether the surgery likely got all the cancer. It also flags whether some may have been left behind.

A negative margin means no cancer cells are found at the outer edge of the removed tissue. This is the goal of most cancer surgery. It generally means the cancer was fully removed, as far as the pathologist can tell.

A positive margin means cancer cells are found right at the edge. This suggests cancer may still be present in the body, just beyond where the surgeon stopped cutting. A positive margin usually means more treatment is needed. That could mean more surgery to remove additional tissue, called re-excision. It could mean radiation aimed at the area instead.

A close margin sits in between. Cancer cells are near the edge but do not actually touch it. There is no single universal distance that defines "close." It depends on the type of cancer. Different cancers use different thresholds, sometimes just a millimeter or two. A close margin raises more concern than a comfortably negative one. It raises less concern than a positive one, though. Whether it needs more treatment depends heavily on your specific cancer type.

You might expect a fixed number, like "2 millimeters is always enough." That is not how it works. The safe margin distance differs by cancer type, tumor behavior, and location. A margin considered adequate for one cancer might be considered too close for a different, more aggressive cancer type. This is why your surgeon and pathologist interpret your specific margin result using standards developed for your specific cancer.

Margin status is one of the most direct, practical results in cancer care. It often changes what happens next, in a concrete way. A clearly negative margin, combined with other favorable features, may mean no further local treatment is needed. A positive or close margin often changes the plan directly. Sometimes that means more surgery. Sometimes it means adding radiation, to lower the risk that any remaining cells cause a recurrence in that same spot.

A negative margin is reassuring, but it is not an absolute guarantee. Cancer cells too small or too few to reach the sampled edge can still exist nearby. Even careful pathology can miss them. Margin status also does not tell you whether cancer has spread elsewhere in the body. It only speaks to the specific area that was surgically removed.

• Was my margin negative, close, or positive, and what specific distance was found?
• What is considered an adequate margin for my specific type of cancer?
• Does my margin status mean I need more surgery, radiation, or neither?
• How does my margin status affect my risk of local recurrence?

• National Cancer Institute — Pathology Reports
• ASCO Connection — Surgical Margins for Breast Cancer