How the Grouping of DCIS Tumors Affects Treatment Options

Most women with DCIS are treated with a lumpectomy. Many women also get radiation after lumpectomy. Radiation lowers the risk of the cancer coming back by about two-thirds (66%). Radiation does have some side effects and is time-consuming. But most women get through treatment without too much hassle. And the cost is usually covered by insurance. The women who are likely to benefit from radiation have a medium-to-high risk of cancer recurrence after lumpectomy.

Still, if you're unlikely to get a significant benefit from radiation, then avoiding radiation might be an option.

DCIS tumors are often classified according to a system called the Van Nuys prognostic index (VNPI), created in 1996 and updated in 2003. The Index tries to help figure out:

• which women will do well with surgery alone (because they have a low risk of recurrence after lumpectomy), and
• which women would get a significant benefit from radiation after surgery (because they have a medium-to-high risk of recurrence after lumpectomy).

This index rates four different aspects of DCIS:

1. size of the cancer (measured in millimeters or "mm"),
2. width of the margin, or the distance between the cancer that was removed and the edge of the normal tissue in your breast (also measured in millimeters),
3. cancer grade (the pattern of the cancer cell growth), and
4. your age when the DCIS is diagnosed.

Each of these four factors is given a score of 1 (low), 2 (medium), or 3 (high), as shown in the table below. The total of the four scores is the total VNPI score. The lowest possible score is 4 (4 times 1) and the highest is 12 (4 times 3). The higher the score, the more likely it is that the cancer will recur.

^{Table from "The University of Southern California/Van Nuys prognostic index for ductal carcinoma in situ of the breast" by Melvin J. Silverstein, American Journal of Surgery, Volume 186, Issue 4, October 2003. Used with the kind permission of Melvin J. Silverstein.}

The main purpose of this rating system is to figure out who is least likely to have a recurrence and therefore might be able to do without radiation. While it's a good idea to spare women treatment if they don't need it, the Van Nuys index is just an educated guess. It does not prove or disprove that the cancer will come back.

Some women want to do everything they possibly can to lower their risk of recurrence and will opt for radiation, since it is effective and relatively easy to take. Others might choose to live with their estimated low risk of recurrence and not have radiation. So this rating system is a tool for a woman to use with her doctor. The value of this tool depends on each woman's unique situation.