The Yale University Experience of Early-Stage Invasive Lobular Carcinoma (ILC) and Invasive Ductal Carcinoma (IDC) Treated with Breast Conservation Treatment (BCT): Analysis of Clinical-Pathologic Features, Long-Term Outcomes, and Molecular Expression of COX-2, Bcl-2, and p53 as a Function of Histology

Abstract

To evaluate our experience of the clinical-pathologic features and outcomes of early-stage Invasive Lobular (ILC) versus Invasive Ductal (IDC) carcinoma treated with breast conservation treatment (BCT). 142 ILC and 1,760 IDC patients were treated with BCT at our institution. All patients underwent breast conserving surgery and radiation therapy (median total dose: 64 Gy). Clinical-pathologic and outcome parameters were analyzed to detect differences between the two cohorts. In addition, COX-2, Bcl-2, and p-53 expression was analyzed from our existing tissue micro-array database. Median follow-up was 6.8 years. A higher percentage of ILC patients presented at >40 years of age (94% ILC versus 89% IDC, p = 0.0353) and had more mammographically occult tumors (p < 0.002). There were no significant differences in T stage, nodal status, family history, final margin, ER/PR/HER-2 status or triple negative tumors (all p-values >0.05). From the immuno-histochemical analysis, expression of p53, COX-2, and Bcl-2 did not differ significantly (all p-values >0.05) between the two cohorts. At 10 years, there was no difference in breast relapse (20% versus 13%, p = 0.25), distant relapse (26% versus 20%, p = 0.28), cause-specific survival (72% versus 84%, p = 0.09) and OS (68% versus 78%, p = 0.08). Patients with ILC had higher contralateral breast relapses (26% versus 12%, p = 0.0006). Patients with early-stage ILC have comparable outcomes to IDC when treated with BCT. Because of the higher risk of contralateral breast cancers for ILC patients, careful evaluation of the contralateral breast will be important in the follow-up of these patients. Future investigations of chemo-preventive strategies to decrease contralateral breast cancers are warranted.

Lobular Breast Cancer and Abdominal Metastases: A Retrospective Review and Impact on Survival

“…It should be noted that in the Pestalozzi et al [12] study of 767 ILC cases, an early advantage in DFS (16% lower event incidence) was observed for the ILC patients, followed by a late advantage for IDC patients after 6 years (54% higher incidence of events for ILC patients). Similar results for OS have been documented, with the majority of studies revealing no difference between the groups at 5 and 10 years [6,7,8,15,21,22,25]. Cristofanilli et al [7] found improved OS for ILC patients at 70 months, while Pestalozzi et al [12] found that ILC patients had an early advantage in OS (16% lower risk of death) but that IDC patients again had a late advantage after 10 years (50% higher risk of death for ILC patients).…”

“…Cristofanilli et al [7] found improved OS for ILC patients at 70 months, while Pestalozzi et al [12] found that ILC patients had an early advantage in OS (16% lower risk of death) but that IDC patients again had a late advantage after 10 years (50% higher risk of death for ILC patients). Previous studies of DSS have found a higher incidence of breast cancer mortality for ILC patients at >10 years, with mixed survival data at earlier time points [6,9,15,25]. In our subgroup analysis, a substantial disadvantage in OS was observed for stage IV ILC patients compared to stage IV IDC patients, with a mean OS of 2.9 versus 6.8 years.…”

“…ILC was also more likely to be mammographically occult with a false-negative rate of 6.8% in our study. This trend has been described in the past with false-negative rates of 19-25% [22,24,25]. The basis for mammographic occultation is postulated to be due to the histologic characteristics of ILC.…”

“…Our study revealed similar DFS, OS, and breast-cancer-specific DSS in the two cohorts with a median follow-up of 4.7 years. The majority of published studies have not found a DFS difference between ILC and IDC patients at 5 and 10 years [4,6,7,8,21,22,25]. Cristofanilli et al [7] found ILC patients to have an improved DFS at 70 months.…”

“…The basis for mammographic occultation is postulated to be due to the histologic characteristics of ILC. ILC is known to have an infiltrative growth pattern with a single-file cellular dispersion in stroma that does not lead to formation of the distinct mass typical of IDC [10,25]. Additionally, ILC is associated with only minimal desmoplastic reaction that, when present, mimics the density of normal breast tissue.…”