P5-14-09: Malignant Calcification Is an Important Prognostic Factor in Women with Invasive Breast Cancer – Suggestion for Regarding It as High-Risk Factor in Current Staging and Adjuvant Treatment Guidelines.

Abstract

Abstract Purpose: To investigate whether calcification is a prognostic factor for breast cancer. Methods: A total of 804 patients with invasive breast cancer diagnosed between 2001 and 2003 were recruited and divided into two groups based on whether they had malignant calcification on mammogram. The association of calcification with lymph node status, grade, tumor size, ER, PR and Her2 status, 8-year disease-free survival (DFS) and overall survival (OS) was evaluated. Survival difference was analyzed by Kaplan-Meier technique. The relative importance of each of the potentially prognostic variables was tested using Cox regression analysis. Results: The incidence of malignant calcification in all breast cancer was 41.5%. Compared with tumor without calcification, those with calcification had a larger size (2.6cm vs 2.1cm, P=0.000), higher axillary lymph node (LN) positive rate (40.1% vs 31.5%, P=0.012), more LN involvement (14.8% vs 9.2%, P=0.000), lower ER (54.3% vs 65.1%, P=0.002) and PR (42.7% vs 60.6%, P=0.000) expression and higher Her2 expression (27.3% vs 14.7%, P=0.000). The 8-year DFS was lower for patients with calcification than those without (89.9% vs. 76.8%, P=0.000). The 8-year OS for tumor with calcification was 82.2%, compared with 92.8% for those without (P=0.000). Subgroup analysis showed that the shorter survival and higher relapse rate for tumors with calcification could be found in both LN- and LN+ patients, also could be found in T1, T2, Grade II, ER+, PR+ and Her2- patients. The existence of calcification, LN stage, tumor size, ER status, and grade were significantly associated with survival in univariate analysis. Further Cox regression analysis demonstrated that calcification and LN stage maintained their prognostic significance in both DFS and OS. The hazard ratios of these factors are listed in Table 1. Conclusions: The existence of calcification is a poor prognostic factor for patients with invasive breast cancer. Its prognostic value is only second to LN status and is higher than the other factors evaluated, including tumor size, grade, and ER, PR status. Thus, breast cancer with calcification should be regarded as a high-risk factor when determining cancer stage and selecting the adjuvant treatment. Discussion: Given the strong prognostic value of calcification revealed in this research, the biological mechanism of its formation and related cell signal pathway should be investigated. Further adjuvant clinical trial should be done to select certain sensitive chemotherapeutic agent or regimen. Some biomarkers have been found to have a role in the formation of calcification and may be targets for treatment. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-09.