Abstract P6-07-28: Assessment of T stage in the multiple breast carcinomas

Abstract

Abstract Background: Tumor size is an important predictor of nodal metastasis, recurrence, distant metastasis in invasive breast carcinomas. T stage assignment of the multiple simultaneous ipsilateral breast carcinomas is based on the largest tumor with the suffix “(m)” to indicate multiplicity in the AJCC staging, and sum of the sizes should not be used. The aim of this study is to compare current AJCC staging and two test models using the aggregate of all tumor foci and the aggregate of all tumor volume in the single and multiple breast carcinomas. Methods: We reviewed original pathologic reports of 1145 consecutive patients with invasive ductal carcinoma, 2003–2004. 131 (11.4%) patients had multiple masses. Three factors were used to compare T stages; (1) the greatest dimension of the largest invasive component (T), (2) the aggregate of all tumor foci (TA), and (3) the aggregate of all tumor volume (TV). T stage follows AJCC (7th ed, 2010) system. TA and TV were categorized as followings: TA1 < 2cm, 2cm ≤ TA2 < 5cm and TA3 ≥ 5cm; TV1 < 8cm³ (average diameter < 2cm), 8 cm³ ≤ TV2 < 125cm³ and TV3 ≥ 125cm³ (average diameter ≥ 5cm). Clinicopathologic parameters were analyzed according to T stage. Results: Axillary lymph node metastasis was more common in the cases with multiple masses (64/131, 48.9%) than single mass (397/1014, 39.2%) and the number of the metastatic lymph node was also higher in multiple cases. Multiple breast carcinomas tended to show frequent recurrence, and disease specific death compared with the single cases in the same stage. (p < 0.05) Among 606 cases of T1, 34 cases were reclassified to TA2 and in 487 cases of the T2, 23 cases were reclassified to TA3. TV also showed reclassification of the cases. Multiplicity, T stage, TA stage, and TV stage were significant factors for nodal positivity in the univariate analysis (p < 0.05). Nodal positivity was remained in the multivariate analysis for recurrence and disease specific death, but the other factors were not significant for nodal involvement, recurrence and disease specific death. Conclusion: Multiple breast carcinomas has adverse patients' outcome than single carcinoma with same T stage of AJCC system and a better staging method is required to cover multiple carcinomas. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-28.