Strategies for optimizing pathologic staging of sentinel lymph nodes in breast cancer patients

Abstract

Due to the extensive pathologic evaluation of the sentinel lymph node (SLN), micrometastases are frequently observed. If micrometastases are clinically relevant, the histopathologic examination of SLNs should be sensitive enough to detect them. The probability of detecting micrometastases was calculated when examining the SLN according to the current Dutch pathology protocol and strategies evaluated to optimize the chance of detection. The dimensions of 20 consecutive axillary SLNs in patients with cT1-2N0 breast cancer were measured. In a mathematical model, the probability of detecting micrometastases in a SLN was calculated. Similarly, strategies to optimize the probability of detecting micrometastases were explored. When applying the pathology guidelines, the calculated probability to detect a micrometastasis was 18% for a 200-microm micrometastasis and 69% for a 2.0-mm metastasis in a median sized SLN. To detect the smallest micrometastasis in a median-sized SLN with a 95% probability, the interval between the sections must be decreased to 200 microm, and 20 levels from both halves must be examined. Given a prognostic significance of micrometastases, our current pathology guidelines are not sensitive enough. The number of sections should be increased, while the interval between cuts should be no more than 200 microm.

Histopathologic Characteristics of Sentinel Lymph Node Biopsy in Breast Carcinoma: Uludağ University Faculty of Medicine Experience

“…6,15 In our study, this ra ti o was 2.2%. Ve ro ne si re por ted n-SLN me tas ta sis in 35-67% of the ca ses with SLN me tas ta sis.…”

“…It was lo wer than the values reported in the li te ra tu re. 15 It may depend on the ex pe ri en ce of the sur ge on and the patho lo gist, fro zen sec ti on ar te facts and se ri al sec ti on in ter val and thick ness in per ma nent sec ti ons.…”

“…There fo re, se ri al sec ti ons with dif fe rent in ter vals are used in dif fe rent la bo ra to ri es. 26 Mo re re cently, mole cu lar bi o logy tech ni qu es ha ve be en used. Their spe si fi city and sen si ti vity is hig her than ro u ti ne me tods.…”

The prognostic impact of occult nodal metastasis in early breast carcinoma

“…As we have found that MM are clinically relevant, to miss detection of MM is unwanted. Using H&E staining, Madsen et al [27] have suggested that the interval between the sections must be decreased to 200 lm, and 20 levels from each of a bisectioned lymph node must be investigated to detect micrometastasis with a 95% probability. Accepting such a labor-intensive method in the routine laboratory may, however, not be feasible.…”

Pathological Examination of Sentinel Lymph Node Biopsy

“…Kesit aralıklarının 200 μm'u geçmemesi önerilmektedir (46). Kendi kurumumuzda 25 µm aralıklar ile 9 ince kesit alınıp, dokunun büyüklüğüne göre lamlara yerleştirilmektedir.…”