We thank Drs. Sobin and Greene for their comments regarding our article.1 Their point is noted, as indeed, according to the TNM staging system, the number of or multiplicity of the tumors should be indicated in parentheses (e.g., T2(m) or T2(5)).2, 3 As the authors accurately indicate, this notation would allow for the identification and separate analysis of such cases. In the staging manual, this provision can be found under “The General Rules of the TNM System” and pertains to any malignancy, not specifically to breast carcinoma.

In our study, we tried to assess the influence of multiplicity on the propensity for metastasis in breast carcinoma patients and found that by using aggregate volumes or surface area measurements as tumor size estimates, multifocal breast tumors were found to have a significantly higher incidence of axillary lymph node metastases than unifocal tumors of a similar volume or surface area. This finding would provide a clinical rationale for designating multifocal tumors in a separate T classification or for changing the rules regarding T classification in multifocal tumors of the breast because they appear to behave in a more aggressive manner than unifocal tumors.


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  • 1
    Andea AA, Bouwman D, Wallis T, Visscher DW. Correlation of tumor volume and surface area with lymph node status in patients with multifocal/multicentric breast carcinoma. Cancer. 2004; 100: 2027.
  • 2
    SobinLH, WittekindC, editors. TNM classification of malignant tumors, 6th edition. New York: John Wiley & Sons, 2002.
  • 3
    FlemingID, CooperJS, HensenDE, et al., editors. AJCC cancer staging manual, 5th edition. Philadelphia: Lippincott-Raven, 1998: 6.