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Significance of Intramammary Lymph Nodes in the Staging of Breast Cancer: Correlation with Tumor Characteristics and Outcome
Significance of Intramammary Lymph Nodes in the Staging of Breast Cancer: Correlation with Tumor Characteristics and Outcome Nassar A, Cohen C, Cotsonis G, et al (Mayo Clinic, Rochester, MN; Emory Univ School of Med, Atlanta, GA; Rollins School of Public Health, Atlanta, GA; et al) Breast J 14:147-152, 2008
Intramammary lymph nodes (intraMLNs) have received little attention as potential prognostic indicators for patients with breast carcinoma. Patients with stage I breast carcinoma and positive intraMLN metastases have been reported to have a poorer prognosis compared to patients with similar stage and negative intraMLN metastases. However, the presence of intraMLN metastases does not appear to influence the survival of patients with stage II breast carcinoma. In the current retrospective analysis, we assessed the clinical significance of intraMLNs and evaluated their role in predicting outcome in patients with breast carcinoma. Between 1995 and 2005, 116 intraMLN specimens were identified. In all, 59 patients (50.8%) were found in association with benign breast conditions and the remaining 57 (49.2%) with primary breast carcinoma. Primary tumor characteristics and axillary lymph node (AxLN) status were recorded. Outcome data were documented. Statistical analysis was performed to detect correlation between intraMLN and tumor characteristics as well as outcome. IntraMLN metastases were found in 26% of all insitu and invasive cancer cases (15/57),
and 32% (15/47) of invasive cancer cases only. Most patients (80%) who had intraMLN metastases also had axillary metastases; however, an isolated intraMLN metastasis was documented in one patient (7%). Univariate analysis revealed that predictors of intraMLN metastases include: tumor size (p ¼ 0.04), tumor grade (p ¼ 0.04), tumor stage (p < 0.001), and AxLN status (p < 0.001). Furthermore patients with intraMLN positive for metastases have a poorer 4-year overall (40% versus 88%; p < 0.001) and diseasefree survival (37% versus 83%; p < 0.001) than patients with negative intraMLN. On multivariate analysis, intraMLN metastasis is not an independent predictor of outcome (disease-free survival: p ¼ 0.350; and overall survival p ¼ 0.138). IntraMLN metastasis is a poor prognostic marker but not an independent predictor of poor outcome in patients with breast carcinoma.
identified intraMLNs in 76 specimens (48%), 25 of which were positive. Ten women had positive intraMLNs and negative axillary nodes. The key issue not addressed by Nassar and colleagues and not addressed well in other available reports is the prognostic significance of a positive intraMLN when axillary lymph nodes are negative. Other authors have commented that intraMLNs are a poor prognostic indicator, but no study has had sufficient numbers of intraMLN-positive, axillary node-negative cases.2,3 In the absence of better data, it is best to be aware of the possibility of intraMLNs, to perform a biopsy on nodules suggestive of malignancy on imaging or identified on sentinel node biopsy, and to treat the rare case of isolated intraMLN metastasis as any nodepositive breast cancer. S. B. Edge, MD
Nassar and colleagues identified a series of women with intraMLNs in a retrospective review of pathology reports, and determined that their findings were similar to those of women from other reports. The reported frequency was low: over an 11-year period, 116 specimens of intraMLN had been identified, only 57 of which were associated with primary breast cancer. Most of the women with intraMLN involvement also had positive axillary nodes—indeed, only 1 woman had intraMLN metastases and negative axillary lymph nodes. The frequency of intraMLNs may be higher than that suggested by Nassar and others. In another recent article, Rampaul and colleagues1 reported the incidence of intraMLNs in 157 mastectomy specimens. They
References 1. Rampaul RS, Dale OT, Mitchell RW, et al. Incidence of intramammary nodes in completion mastectomy specimens after axillary sampling: implications for breast conserving surgery. Breast. 2008;17:195-198. 2. Shen J, Hunt KK, Mirza NQ, et al. Intramammary lymph node metastases are an independent predictor of poor outcome in patients with breast carcinoma. Cancer. 2004; 101:1330-1337. 3. Guth AA, Mercado C, Roses DF, et al. Intramammary lymph nodes and breast cancer: a marker for disease severity, or just another lymph node? Am J Surg. 2006;192:502-505.
Breast Diseases: A Year BookÒ Quarterly Vol 19 No 3 2008
225
Intramammary lymph nodes (intraMLNs) have received little attention as potential prognostic indicators for patients with breast carcinoma. Patients with stage I breast carcinoma and positive intraMLN metastases have been reported to have a poorer prognosis compared to patients with similar stage and negative intraMLN metastases. However, the presence of intraMLN metastases does not appear to influence the survival of patients with stage II breast carcinoma. In the current retrospective analysis, we assessed the clinical significance of intraMLNs and evaluated their role in predicting outcome in patients with breast carcinoma. Between 1995 and 2005, 116 intraMLN specimens were identified. In all, 59 patients (50.8%) were found in association with benign breast conditions and the remaining 57 (49.2%) with primary breast carcinoma. Primary tumor characteristics and axillary lymph node (AxLN) status were recorded. Outcome data were documented. Statistical analysis was performed to detect correlation between intraMLN and tumor characteristics as well as outcome. IntraMLN metastases were found in 26% of all insitu and invasive cancer cases (15/57),
and 32% (15/47) of invasive cancer cases only. Most patients (80%) who had intraMLN metastases also had axillary metastases; however, an isolated intraMLN metastasis was documented in one patient (7%). Univariate analysis revealed that predictors of intraMLN metastases include: tumor size (p ¼ 0.04), tumor grade (p ¼ 0.04), tumor stage (p < 0.001), and AxLN status (p < 0.001). Furthermore patients with intraMLN positive for metastases have a poorer 4-year overall (40% versus 88%; p < 0.001) and diseasefree survival (37% versus 83%; p < 0.001) than patients with negative intraMLN. On multivariate analysis, intraMLN metastasis is not an independent predictor of outcome (disease-free survival: p ¼ 0.350; and overall survival p ¼ 0.138). IntraMLN metastasis is a poor prognostic marker but not an independent predictor of poor outcome in patients with breast carcinoma.
identified intraMLNs in 76 specimens (48%), 25 of which were positive. Ten women had positive intraMLNs and negative axillary nodes. The key issue not addressed by Nassar and colleagues and not addressed well in other available reports is the prognostic significance of a positive intraMLN when axillary lymph nodes are negative. Other authors have commented that intraMLNs are a poor prognostic indicator, but no study has had sufficient numbers of intraMLN-positive, axillary node-negative cases.2,3 In the absence of better data, it is best to be aware of the possibility of intraMLNs, to perform a biopsy on nodules suggestive of malignancy on imaging or identified on sentinel node biopsy, and to treat the rare case of isolated intraMLN metastasis as any nodepositive breast cancer. S. B. Edge, MD
Nassar and colleagues identified a series of women with intraMLNs in a retrospective review of pathology reports, and determined that their findings were similar to those of women from other reports. The reported frequency was low: over an 11-year period, 116 specimens of intraMLN had been identified, only 57 of which were associated with primary breast cancer. Most of the women with intraMLN involvement also had positive axillary nodes—indeed, only 1 woman had intraMLN metastases and negative axillary lymph nodes. The frequency of intraMLNs may be higher than that suggested by Nassar and others. In another recent article, Rampaul and colleagues1 reported the incidence of intraMLNs in 157 mastectomy specimens. They
References 1. Rampaul RS, Dale OT, Mitchell RW, et al. Incidence of intramammary nodes in completion mastectomy specimens after axillary sampling: implications for breast conserving surgery. Breast. 2008;17:195-198. 2. Shen J, Hunt KK, Mirza NQ, et al. Intramammary lymph node metastases are an independent predictor of poor outcome in patients with breast carcinoma. Cancer. 2004; 101:1330-1337. 3. Guth AA, Mercado C, Roses DF, et al. Intramammary lymph nodes and breast cancer: a marker for disease severity, or just another lymph node? Am J Surg. 2006;192:502-505.
Breast Diseases: A Year BookÒ Quarterly Vol 19 No 3 2008
225