[276] Clinicopathologic Profile and Outcomes of Microinvasive Breast Cancer – An Analysis of 42 Cases

Lamis A Shatat, Nika Gloyeske, Rashna Madan, Ossama Tawfik, Fang Fan. University of Kansas, Kansas City, KS

Background: The clinical implication of microinvasive breast carcinoma, especially when multiple foci are identified, is still not clearly defined. This study is designed to collect clinicopathologic and follow up data on patients with microinvasive breast carcinoma.
Design: Microinvasive breast carcinoma cases were identified from our surgical pathology files between 1998 and 2012. Patients treated with neoadjuvant therapy were excluded from the study. Histologic data including invasive breast cancer type, nuclear grade, number of microinvasive foci and lymph node status were collected. The type, size, and grade of the associated in-situ component were also recorded. Biomarkers were recorded from the in-situ component due to the inconsistent availability of markers on the microinvasive component. Clinical follow up data such as incidence of local recurrence, distant metastasis as well as survival was also noted.
Results: Forty two microinvasive carcinoma cases were identified among 1180 invasive breast cancer cases for the same time period, representing 3.6% of the overall invasive cases. The mean age of the 42 patients was 58 years (range 33-90 years). The clinicopathologic profiles of these cases are shown in Table 1.

Table 1
Pathologic FeaturesNumber of Cases (n=42)
Number of Microinvasive Foci≤3 foci: 29
 4-9 foci: 6
 ≥10 foci: 3
 Unknown: 4
Type of Microinvasive CarcinomaDuctal: 39; Mucinous: 3
Nuclear GradeNuclear grade 1: 5
 Nuclear grade 2: 10
 Nuclear grade 3: 27
Associated Ductal Carcinoma In-situComedo: 26; Non-comedo: 13; unknown: 3
In-situ GradeLow to intermediate: 7
 High: 34
 Unknown: 1
In-situ Size (cm)0.4-6.5 (mean: 2.3)
Biomarkers of In-situ ComponentER+/Her2+: 5
 ER+/Her2-: 10
 ER-/Her2+: 13
 ER-/Her2-: 5
 Unknown: 9
Lymph Node StatusNo nodal metastasis: 32
 Positive isolated tumor cells: 3
 Positive micrometastasis: 1
 Positive macrometastasis: 1
 Unknown: 5
Follow up (1-112 months)Alive with no local recurrence or distant metastasis: 36
 Death: 1 (respiratory failure, no evidence of metastasis)
 Unknown: 5

Conclusions: Microinvasive breast carcinoma represents a small portion of invasive carcinomas. The majority of cases is associated with high grade ductal carcinoma in-situ and have high nuclear grade. There is no consistent ER/Her2 expression pattern in the associated in-situ carcinoma. The number of microinvasive foci, the extent of the in-situ component and the biomarker expression pattern do not appear to impact the overall excellent outcome.
Category: Breast

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 20, Wednesday Morning


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