[147] Survival of Breast Intracystic/Solid Papillary Carcinoma Compared to Ductal Carcinoma In Situ.

Leela Elavathil, Jonathon Sussman, Noori Akhtar-Danesh, Asmaa Manan, Alice Lytwyn. Juravinski Hospital, Hamilton, ON, Canada; Juravinski Cancer Centre, Hamilton, ON, Canada; McMaster University, Hamilton, ON, Canada

Background: It is suggested that breast intracystic and solid papillary carcinomas (I/SPC) that lack peripheral myoepithelial cells are low grade invasive carcinomas (IC), and rare axillary node involvement is cited as evidence of malignancy. But non-papillary DCIS may lack myoepithelial cells. Axillary metastases occur in 1-2% of patients with DCIS; these are attributed to occult IC. Therefore, myoepithelial cell absence and regional metastases do not distinguish between in situ and IC. Survival may be a more valid outcome measure.
Design: We searched the pathology database from 1987-2008 for intracystic and solid papillary carcinomas and DCIS, and excluded those with previous ipsilateral breast carcinoma or without treatment information. Two pathologists independently reviewed all H&E slides, and p63 and SMMHC stains of selected blocks of I/SPC cases. Cases with peripheral myoepithelial cells, carcinoma beyond the cyst wall or with IC in adjacent breast were excluded. Survival was obtained from medical charts, family physicians, and death registry. Survival analysis with Cox proportional hazards model adjusted for all variables was performed.
Results: 30 intracystic and 4 solid papillary carcinomas and 206 DCIS were the study group.

Characteristic	IPC (n=34)	DCIS (n=172)
Median age, yrs (range)	70 (36-88)	59 (37-85)
Axillary dissection	6 (18%)	17 (10%)
Positive axillary lymph nodes	0 (0%)	0 (0%)
Median size, mm (range)	15 (5-80)	15 (2-60)
Nuclear grade 1	2 (6%)	19 (10%)
Nuclear grade 2	32 (94%)	96 (56%)
Nuclear grade 3	0 (0%)	57 (33%)
Comedo pattern	1 (3%)	107 (62%)
Positive margin	4 (12%)	24 (14%)
Optimum treatment*	18 (53%)	150 (87%)

*Mastectomy; or excision with radiation

Median follow-up was 73 months (range 13-167) for I/SPC and 84 months (range 8-168) for DCIS. There were 9 (26%) deaths in the I/SPC group and 10 (6%) in the DCIS group (Hazard ratio (HR) 5.2, p<0001). Among age, size, nuclear grade, comedo, margin, and treatment status, only age showed significant effect on overall survival (HR 2.5, p=0.001). After adjusting for age, HR for overall survival was 2.5 (95% confidence interval 0.8-7.3, p=0.102).
Conclusions: The difference in overall survival between patients with I/SPC and DCIS was mainly due to differences in age. After adjustment for age, I/SPC and DCIS did not differ significantly in overall survival. However, further studies are warranted to confirm these findings.
Category: Breast

Monday, February 28, 2011 1:00 PM

Poster Session II # 40, Monday Afternoon