Non-sentinel lymph node involvement in patients with breast cancer and sentinel node micrometastasis; too early to abandon axillary clearance

AIMS

It has been suggested that patients with T1-2 breast tumours and sentinel node (SLN) micrometastases, defined as foci of tumour cells smaller than 2 mm, may be spared completion axillary lymph node dissection because of the low incidence of further metastatic disease. To gain insight into the extent of non-sentinel lymph node (n-SLN) involvement, SLNs and complementary axillary clearance specimens in patients with SLN micrometastases were examined.

METHODS

A set of 32 patients with SLN micrometastases was selected on the basis of pathology reports and review of SLNs. Five hundred and thirteen n-SLNs from the axillary clearance specimens were serially sectioned and analysed by means of immunohistochemistry for metastatic disease. Lymph node metastases were grouped as macrometastases (> 2 mm), and micrometastases (< 2 mm), and further subdivided as isolated tumour cells (ITCs) or clusters.

RESULTS

In 11 of 32 patients, one or more n-SLN was involved. Grade 3 tumours and tumours > 2 cm (T2-3 v T1) were significantly associated with n-SLN micrometastases as clusters (grade: odds ratio (OR), 8.3; 95% confidence interval (CI), 1.4 to 50.0; size: T2-3 tumours v T1: OR, 15; 95% CI, 2.18 to 103.0). However, no subgroup of tumours with regard to size and grade was identified that did not have n-SLN metastases.

CONCLUSIONS

In patients with breast cancer and SLN micrometastases, n-SLN involvement is relatively common. The incidence of metastatic clusters in n-SLN is greatly increased in patients with T2-3 tumours and grade 3 tumours. Therefore, axillary lymph node dissection is especially warranted in these patients. However, because n-SLN metastases also occur in T1 and low grade tumours, even these should be subjected to routine axillary dissection to achieve local control.

Decreased interstitial apolipoprotein A-I levels in IDDM patients with diabetic nephropathy

The risk of cardiovascular morbidity and mortality is highly increased in patients with diabetic nephropathy. Postulating that the generalized vasculopathy observed in these patients may enhance transcapillary filtration of lipids and lipoproteins resulting in a more atherogenic interstitial lipid profile, we set out to analyze the composition of their interstitial fluid. We studied healthy control subjects (n = 9), normoalbuminuric insulin-dependent diabetes mellitus (IDDM) patients (n = 16), and IDDM patients with diabetic nephropathy (n = 11) matched for age, body mass index, smoking habits, duration of diabetes, and metabolic control. Interstitial fluid was collected after an overnight fast by applying mild suction (200 mmHg) to the skin. Interstitial apolipoprotein A-I (apoA-I) levels were significantly lower in patients with nephropathy (0.18 +/- 0.10 milligram [mean +/- SD]) compared with normoalbuminuric diabetic patients (0.29 +/- 0.08 milligram) and healthy control subjects (0.30 +/- 0.09 milligram). Interstitial apolipoprotein B:apoA-I ratios tended to be higher in patients with diabetic nephropathy. In these patients, normal interstitial low-density lipoprotein cholesterol concentrations were observed in the presence of lower apoA-I levels. Transcapillary filtration of apoA-I was significantly lower in patients with diabetic nephropathy. Furthermore, an altered multiple regression model explaining interstitial apoA-I levels was observed in diabetic nephropathy. In this model, transcapillary protein (IgG) filtration and serum apoA-I levels no longer explained interstitial apoA-I levels. If we assume that interstitial apoA-I is involved in reverse cholesterol transport, these data suggest a more atherogenic interstitial lipoprotein profile in IDDM patients with nephropathy.