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SEER Inquiry System - Report
Produced: 05/24/2026 3:52 PM
Question 20110111
Inquiry Details
References:
2007 MP/H Rules
Question:
MP/H Rules/Multiple primaries--Breast: How many primaries are to be abstracted for a patient with a history of right breast ductal carcinoma in situ diagnosed in 2007 treated with bilateral mastectomies and a right chest wall mass excised in 2010 that revealed infiltrating ductal carcinoma? See Discussion.
Discussion:
The patient's right breast DCIS in 2007 was treated with bilateral mastectomies with negative lymph nodes and negative margins. The patient refused Tamoxifen at that time. In 2010 a right chest wall mass excision revealed infiltrating ductal carcinoma with negative axillary lymph nodes. The physician states this is a recurrence. Per MP/H rule M8 this invasive tumor must be abstracted as a new primary. Would the primary site of the 2010 tumor be coded to breast or chest wall given that the patient has a previous mastectomy?
Answer:
This tumor in 2010 represents a recurrence; it is not a new primary. This second tumor would be coded as a new primary ONLY if the pathology report states that it originated in breast tissue that was still present on the chest wall. When there is no mention of breast tissue in a subsequent resection, the later occurring tumor is regional metastases to the chest wall (i.e., a recurrence of the original tumor).
In turn, this means that there was at least a focus of invasion present in the original tumor that was not identified by the pathologist. The behavior code on the original abstract must be changed from a /2 to a /3 and the stage must be changed from in situ to localized.
