[131] Significance of Partial Reverse Cell Polarity in Breast Cancer (BC) – Part of a Spectrum of Micropapillary (MP) Carcinoma?

G Acs, NN Esposito, Z Rakosy, C Laronga, PJ Zhang. Moffitt Cancer Center, Tampa, FL; Women's Pathology Consultants, Ruffolo Hooper & Associates, Tampa, FL; University of Pennsylvania Medical Center, Philadelphia, PA

Background: Invasive MP carcinomas (IMPC) of the breast are aggressive tumors frequently associated with lymphatic invasion (LVI) and metastasis even when MP features are very focal. We have noticed that some agressive BC showing lymphatic spread have occasional tumor cell clusters reminiscent of IMPC without the characteristic prominent retraction artifact seen in IMPC.
Design: We prospectively selected 1323 invasive ductal BC for the study. All H&E slides were reviewed and the presence and extent of MP differentiation and retraction artifact were determined. One representetative block per case was used for immunostaining for EMA. Partial reverse cell polarity (PRCP) was defined as prominent linear EMA reactivity on at least part of the periphery of tumor cell clusters usually associated with decreased cytoplasmic staining. The clinicopathologic features of BC with PRCP were compared to IMPC and ductal BC without this feature (IDC).
Results: Of the 1323 cases 96 (7.3%) and 92 (7.0%) showed MP features and the presence of PRCP, respectively. The results are summarized in the Table. Hormone receptor and HER2 status showed no correlation with the presence of PRCP or MP features.

Summary of results
IDC (n=1135)PRCP (n=92)IMPC (n=96)p
Age (ys)56 (56.9±0.4)55.5 (55.6±1.3)59.5 (58.8±1.4)0.193
Size (cm)1.5 (1.9±0.1)1.7 (2.1±0.1)2.2 (2.7±0.2)<0.0001
Grade (%)Low213 (18.8)2 (2.2)10 (10.4)0.0005
Intermediate510 (44.9)51 (55.4)50 (52.1)
High412 (36.3)39 (42.4)36 (37.5)
Percent retraction20 (26.2±0.8)10 (17.7±2.660 (57.9±2.8<0.0001
LVI (%)Present353 (31.1)89 (96.7)81 (84.4)<0.0001
Absent782 (68.9)3 (3.3)15 (15.6)
LN metastasis (%)Present416 (36.7)79 (85.9)75 (78.1)<0.0001
Absent719 (63.3)13 (14.1)21 (21.9)
EMA staining255 (226.2±5.3)200 (194.3±7.0)100 (106.2±9.4)<0.0001

Conclusions: The presence of PRCP in BC is strongly associated with lymphatic tumor spread even if present only focally. BC with PRCP appear to have the same implication as MP differentiation and may represent part of a spectrum of IMPC. Complete or partial reversal of cell polarity may play a significant role in lymphatic tumor spread.
Category: Breast

Monday, March 22, 2010 1:00 PM

Poster Session II # 37, Monday Afternoon


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