Ductal carcinoma in situ (also called DCIS) is breast cancer, which has not invaded outside of the primary milk ducts. Consequently, it has no way to spread to other parts of the body or the lymph nodes. The reported cure rate for women diagnosed with DCIS is about 97% – 98%. It is not 100% because small areas that have invaded outside of the milk duct are not identified during the breast tissue examination. Unfortunately, few studies have examined the risk of breast recurrence in patients who have had a nipple-sparing mastectomy for pure DCIS, with no invasion.
Recently, a rather sizable study from South Korea sheds new light on this very issue. The researchers reported on a total of 199 consecutive patients diagnosed with pure DCIS and treated with nipple-sparing mastectomy with breast reconstruction. Over 90% of the patients had sentinel node biopsies performed at the time of this surgery. It is important to note that no patient had radiation therapy following their initial surgery. All patients had reconstruction, 65% performed with a flap, and 35% had reconstruction with an implant or expander.
The good news is that only 5% (10 patients) had a recurrence in the breast at five years. The recurrence was invasive in six of the ten patients. Of the ten patients with a recurrence, five recurred in the nipple, which is only 2.5% of the total number of patients having a mastectomy. At ten years, the recurrence rate was 4.5%, and the nipple recurrence rate was up slightly to 3%. The overall survival rate of the entire group was 98.5%. The average time between surgery and a recurrence was approximately four years.
It appears that factors that may increase the risk of recurrence in the breast include cancers equal to or greater than 4 cm in size and a negative progesterone receptor status. One factor taken into account by most when evaluating the successful outcome of nipple-sparing mastectomy is the distance of cancer to the nipple. Most surgeons would like to see approximately 2 cm distance between cancer and the back of the nipple. However, others will accept any distance between cancer and the nipple as long as the tissue biopsy beneath the nipple is free of tumor. Because the number of recurrences in this study was small, the researchers could not evaluate tumor to nipple distance as a risk factor for recurrence in the breast.
In summary, this study showed that recurrence in the breast in patients undergoing nipple-sparing mastectomy for pure DCIS was very low. They found that only 4.5% of patients having this procedure suffered from a recurrence in the breast at ten years and that only 3% recurred in the nipple. One can conclude that nipple-sparing mastectomy for women with pure DCIS is a safe and effective procedure.