Four types of Ipsilateral Breast Tumor Recurrence (IBTR) after breast‐conserving surgery: Classification of IBTR based on precise pathological examination

Abstract

We classified ipsilateral breast tumor recurrences (IBTRs) based on strict pathological rules. Ninety-six women who were surgically treated for IBTR were included. IBTRs were classified according to their origins and were distinguished based on strict pathological rules: relationship between the IBTR and the primary lumpectomy scar, surgical margin status of the primary cancer, and the presence of in situ lesions of IBTR. The prognosis of these subgroups were compared to that of new primary tumors (NP) in the narrow sense (NPn) that occurred far from the scar. Distant-disease free survival of IBTR that occurred close to the scar with in situ lesions and a negative surgical margin of the primary cancer (NP occurred close to the scar, NPcs) was similar to that of NPn. In contrast, IBTR that occurred close to the scar without in situ lesions (true recurrence (TR) that arose from residual invasive carcinoma foci, TRinv) had significantly poorer prognosis than NPn. IBTR that occurred close to the scar with in situ lesions and a positive surgical margin of the primary cancer (TR arising from a residual in situ lesion, TRis) had more late recurrences than NPcs. Precise pathological examinations indicated four distinct IBTR subtypes with different characteristics. Key words: breast cancer, breast-conserving surgery, ipsilateral breast tumor recurrence, new primary tumor, true recurrence The concept of classifying ipsilateral breast tumor recurrences (IBTRs) into two categories was introduced by Veronesi in 1995. 1 True recurrences (TR) were described as cases consistent with the regrowth of malignant cells not removed by surgery or not killed by radiotherapy, and new primary tumors (NP) were described as de novo malignan-cies arising from mammary epithelial cells of the residual breast tissue. Several studies have attempted to classify the two distinct types of IBTR by using tumor location, histologi-cal subtype, surgical margin status of the primary tumor, estrogen receptor status and human epidermal growth factor receptor 2 (HER2) status. These studies demonstrated that patients with NP had significantly better survival rates than patients with TR. 2-6 Although the importance of classifying IBTR is well known, IBTR is difficult to classify, especially the IBTR that occurs near the primary lumpectomy scar. In this study, we classified IBTR into four subgroups based on simple pathological rules and investigated the clinical characteristics of these IBTRs. MATERIALS AND METHODS Study population We reviewed the records of 3876 patients with breast cancer who underwent breast-conserving surgery from 1986 to 2007

Impact of an In Situ Component on Outcome After In-Breast Tumor Recurrence in Patients Treated with Breast-Conserving Therapy

“…Most prior studies have differentiated NP from TR with location as the main distinguishing criterion 13–16,18–22,33–35 . Under this classification schema, NPs have been shown to arise sooner after primary surgery and generally have better prognosis than TR in the tumor bed 13,15,16,19 .…”

“…An alternate method of classifying recurrences may be to consider the presence of an in situ component 21,22 . Invasive breast tumors often develop from in situ lesions, such as ductal carcinoma in situ (DCIS) and, indeed, the majority of primary invasive ductal cancers have an accompanying intraductal component 23–26 .…”

Comparison of Recurrence Rate Between Re-Excision With Radiotherapy and Radiotherapy-Only Groups in Surgical Margin Involvement of In Situ Carcinoma

“…Quadrants in which IBTR occurs after BCS have been investigated in several studies [ 15 16 ]. The location of recurrence can be a factor in determining whether radical surgery should be performed at the time of the initial operation.…”

Invasive Cancer Confined to the Nipple of the Conserved Breast: A Case Report

“…At present, there are no established criteria that clearly classify local recurrences within the breast as either true recurrences or second cancers (metachronal ipsilateral breast cancers). Based on previous studies, these differ in prognoses and therapeutic strategies [ 11 , 12 ]. In our present case, if histopathological status of the nipple was ductal carcinoma in situ, we agreed that the lesion was a second cancer.…”