Clinical outcome of patients with lymph node‐negative breast carcinoma who have sentinel lymph node micrometastases detected by immunohistochemistry

• Published in: Cancer 2005-04, Vol.103 (8), p.1581-1586
• Main Authors: Chagpar, Anees, Middleton, Lavinia P., Sahin, Aysegul A., Meric‐Bernstam, Funda, Kuerer, Henry M., Feig, Barry W., Ross, Merrick I., Ames, Frederick C., Singletary, S. Eva, Buchholz, Thomas A., Valero, Vincente, Hunt, Kelly K.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Biological and medical sciences; Breast carcinoma; Breast Neoplasms - chemistry; Breast Neoplasms - drug therapy; Breast Neoplasms - pathology; Carcinoma, Ductal, Breast - pathology; Carcinoma, Lobular - pathology; Chemotherapy, Adjuvant; Female; Gynecology. Andrology. Obstetrics; Humans; Immunoenzyme Techniques; immunohistochemistry; Lymph Nodes - pathology; Lymphatic Metastasis - diagnosis; Mammary gland diseases; Medical sciences; micrometastases; Middle Aged; Neoplasm Staging; Predictive Value of Tests; sentinel lymph node; Sentinel Lymph Node Biopsy; survival; Survival Rate; Treatment Outcome; Tumors
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/cncr.20934

BACKGROUND The ideal pathologic assessment of sentinel lymph nodes (SLNs) in patients with breast carcinoma remains controversial. The authors evaluated how detailed assessment of SLNs using immunohistochemistry (IHC) and serial sectioning would affect treatment decisions and outcomes in patients with breast carcinoma who had negative SLNs on standard hematoxylin and eosin staining. METHODS The SLNs from patients who were treated between June 1998 and June, 1999 and who had negative lymph node status determined by hematoxylin and eosin staining (n = 84 patients) were evaluated further with serial sectioning and cytokeratin IHC. Patients were offered adjuvant therapy based on primary tumor factors. RESULTS The median patient age was 57 years, and the median tumor size was 1.2 cm. At a median follow‐up of 40.2 months, 81 patients (96%) were alive with no evidence of disease, 1 patient was alive with disease, 1 patient had died of disease, and 1 patient had died of other causes. Fifteen patients (18%) had micrometastases identified on IHC. Of the total 84 patients, information regarding adjuvant therapy was not available for 5 patients. Of the remaining 79 patients, 10 patients (13%) were not offered adjuvant chemotherapy but had positive SLN status determined by IHC. SLN status based on IHC evaluation did not correlate with age (P = 0.077), tumor size (P = 0.717), grade (P = 0.148), estrogen receptor status (P = 1.000), or lymphovascular invasion (P = 0.274). Furthermore, IHC‐detected positive SLN status did not correlate with distant metastasis (P = 0.372) or overall or distant metastasis‐free survival (P = 0.543 and P = 0.540, respectively). CONCLUSIONS Although the finding of SLN micrometastases by IHC may change management in > 12% of patients, preliminary results suggested that such micrometastases do not affect outcomes significantly. Cancer 2005;103:1581–6. © 2005 American Cancer Society. Extensive evaluation of sentinel lymph nodes with serial sectioning and immunohistochemistry may upstage 18% of patients with breast carcinoma. This stage migration may affect management in > 12% of patients, but the impact of immunohistochemistry detected sentinel lymph node micrometastases on outcome remains unclear.