Tumor Associated Inflammation Correlates with Poor Prognosis in Pregnancy Associated Breast Cancer
Luis Z Blanco, Jr., Aparna Mahajan, Seema A Khan, Megan E Sullivan, Stephen M Rohan, Kalliopi P Siziopikou. Northwestern University Feinberg School of Medicine, Chicago, IL
Background: Pregnancy associated breast cancer (PABC) is diagnosed during or after recent pregnancy and is associated with a poor prognosis. It has been proposed that, in some women, the mammary microenvironment might become tumor promoting after pregnancy as the mammary gland is remodeled to its pre-pregnant state. This pro-inflammatory state is thought to support tumor cell dissemination. In this study we evaluated pathologic characteristics of PABC and the presence and degree of tumor associated inflammation (TAI), and perilobular inflammation (PLI) away from the mass, to determine if these features were associated with worse prognosis.
Design: Our patient population consisted of 38 patients diagnosed with PABC within 2 years of pregnancy (1998-2011, mean age:35.5, range 25-48). Age-matched nulliparous women with a diagnosis of breast cancer served as controls (mean age:37.5, range 29-48). Pathologic tumor characteristics evaluated included histologic type, tumor grade, tumor size, presence of lymphatic vascular invasion (LVI), lymph node status, breast tumor markers (ER, PR, HER2 and p53) and the presence of TAI and PLI. The degree of TAI and PLI were graded as 0-absent, 1-mild (<10%), 2-moderate (10-50%) or 3-severe (>50%).
Results: Overall, women with PABC were more likely than controls to have grade 3 infiltrating ductal tumors (76% vs. 26%, p <0.0001) and triple negative phenotype (34% vs. 3%, p <0.001). Women with PABC had more positive lymph nodes (61% vs. 45%) and higher rates of p53 expression (31% vs. 16%). 96% of PABC cases had TAI, 12 mild, 8 moderate and 5 severe. Of interest, all 5 severe TAI were grade 3 ductal tumors with positive lymph nodes. 73% of controls showed TAI, 13 mild and 3 moderate. PABC cases were more likely than controls to have moderate to severe TAI (50% vs. 14%, p<0.04) and PLI (85% vs. 55%, p<0.05). There was no difference between PABC and controls in regards to tumor size, LVI or HER2 status.
Conclusions: 1. PABCs diagnosed within 2 years of pregnancy are more likely to be grade 3 triple negative ductal carcinomas often with positive lymph nodes 2. The majority of PABC have TAI (50% moderate or severe) 3. Severe TAI is more likely in PABC (1 in 5 cases) 4. Severe TAI is associated with lymph node involvement in PABC and 5. PABC is more likely to have PLI. Our findings suggest that TAI and PLI may play an important role in tumor metastasis in PABC and contribute to the poor prognosis in these patients.
Wednesday, March 6, 2013 1:00 PM
Poster Session VI # 24, Wednesday Afternoon