The prognostic significance of axillary lymph-node micrometastases in breast cancer patients

doi:10.1016/j.ejso.2005.01.001

European Journal of Surgical Oncology (EJSO)

Volume 31, Issue 5, June 2005, Pages 500-505

https://doi.org/10.1016/j.ejso.2005.01.001 Get rights and content

Abstract

Aims

We analysed the results of regional community practice to determine the prognosis of axillary lymph-node micrometastases in women with breast cancer.

Methods

Patient data were retrieved from the population-based Eindhoven Cancer Registry in The Netherlands. Between 1975 and 1997, 10,111 patients were diagnosed as having invasive breast cancer. We compared three subgroups: patients without axillary involvement (the pN0 group), patients with axillary micrometastasis (≤2 mm, the pN1a group), and patients with a macro metastasis in only one lymph node (>2 mm, the pN1 group). Follow-up was completed until April 2002.

Results

The relative risk (RR) of dying comparing the pN1a group and the pN1 group to the pN0 group was 1.32 and 1.34, respectively. Excluding the adjuvantly treated patients, the RR of dying was 1.51 and 1.91, respectively for the pN1a group and the pN1 group vs. the pN0 group.

Conclusion

This outcome data of nearly 25 years of community practice show that breast cancer patients with axillary lymph node micrometastasis have a significantly worse survival rate than those without independent of age or tumour size. Adjuvant systemic therapy should be contemplated when treating these patients.

Introduction

The detection of metastases in axillary lymph nodes of patients with breast cancer is highly dependent on the methods used to find them. Historically, a lymph node examination is based on haematoxylin and eosin (H&E) staining of one or two sections through the largest diameter of the lymph node. Micrometastases were defined by the American Joint Committee on Cancer as metastatic lesions no larger than 2.0 mm in greatest dimension. In the fifth edition of AJCC cancer staging manual these lesions were classified as pN1a. However, a footnote was added stating that the prognosis of patients with pN1a is similar to that of patients with pN0.¹ Earlier editions had classified patients with micrometastatic disease as pN0.

In the ongoing debate concerning the prognostic significance of micrometastatic axillary breast disease, we present the results of nearly 25 years of regional community practice. In a population of 10,111 breast cancer patients, we found 179 patients with H&E micrometastasis and compared them to 4377 patients without axillary involvement and to 640 patients with only one positive lymph node.

Section snippets

Data collection

Patient data were retrieved from the population-based Eindhoven Cancer Registry, which serves a population of nearly one million inhabitants in the south-eastern Netherlands (6% of the Dutch population). Data were collected by the cancer registry from copies of the pathology reports made by 10 pathologists in three different laboratories and the medical records of eight community hospitals and one department of radiotherapy.

In the period 1975–1997, there were, 10,111 patients diagnosed as

General population characteristics according to axillary nodal status

The mean age at the time of diagnosis of the patients with micrometastatic breast cancer was slightly lower than those with node-negative disease, although this was not statistically significant (Table 1). There was also no significant difference in age observed between the patients with micrometastases and those with a macro metastasis in one lymph node. Patients with micrometastatic disease had larger tumours than the node-negative patients (p=0.001). No differences in tumour size were

Discussion

This large, population-based study with long term follow-up shows that breast cancer patients with micrometastases detected by H&E staining alone without serial sectioning have a prognosis which is worse than that of node-negative patients and better than that of patients with macro metastatic disease in only one lymph node.

Overlooking the literature, the significance of finding axillary micrometastasis in breast cancer patients remains a controversial topic. Most early studies showed no

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