Lobular carcinoma in-situ as a component of breast cancer: the long term outcome in patients treated with breast conservation therapy

Purpose: There is a paucity of data regarding prognostic implications of having LCIS as a histologic component of invasive breast carcinomas or ductal carcinoma in situ. The purpose of this study is to assess the long term outcome of patients with breast carcinoma with a component of LCIS, treated with conservative surgery and radiation therapy. Materials and Methods: The pathology reports of all patients treated with conservative surgery and radiation therapy at our institution prior to 1993 were reviewed to identify patients who had LCIS as a histologic component. A total of 51 patients were identified. Primary histology of the 51 patients were as follows: 53% infiltrating lobular, 20% invasive and intraductal, 18% invasive ductal, 10% intraductal. There were no patients treated who had LCIS only. 1023 patients treated conservatively during the same time interval without LCIS served as a control group. All patient characteristics, staging, treatment and outcome variables were entered into a computer database. Overall survival, disease-free survival, local-regional relapse and distant metastasis rates were calculated from the date of diagnosis to the most recent follow-up. Results: As of (3(96)), the median follow-up for the LCIS containing group and control group was 10.6 and 11.4 years, respectively. There were no significant differences in age of presentation, clinical stage, nodal status, estrogen receptor status, or adjuvant therapy received between the two groups. Twenty-two patients (43%) in the LCIS group underwent re-excision. Of those, 68% had residual LCIS in the re-excision specimen. LCIS was characterized as focal in 29%, diffuse in 25%, and not specified in all other cases. Forty-one percent of patients with LCIS containing tumors had a positive family history. The primary histology of the two populations differed significantly with a larger percentage of infiltrating lobular primaries in the LCIS group (53% vs. 4%, p<.001). The LCIS group also differed from the control group with respect to the percentage of patients with bilateral disease (17% vs. 8%, p=0.052), and the percentage of patients with 'false negative' mammograms (20% vs. 10%, p=0.002). There was no statistically significant difference between the LCIS group and control group in the 10 year overall survival (67% vs. 72%), distant disease free survival (62% vs. 79%) or relapse free survival (50% vs. 68%). Of note, the 10 year ipsilateral breast tumor recurrence free survival between the two groups was not significantly different (77% LCIS vs. 84% control). Conclusion: Patients with lobular carcinoma in situ as a histological component of breast cancer do not carry a worse prognosis than breast cancer patients without an LCIS component. Furthermore, the comparable local control rates between conservatively treated patients with or without LCIS suggests that patients with a histologic component of LCIS are suitable candidates for conservative surgery and radiation therapy