Impact of Histological Type and Grade on the Diagnostic Accuracy of Intraoperative Frozen Section for Detecting Breast Cancer Metastasis to Axillary Sentinel Lymph Nodes

Abstract

Intraoperative sentinel lymph node (SLN) evaluation is the standard of care in patients with clinically nodenegative breast cancer. The most common histological subtype of breast carcinoma is invasive ductal carcinoma (IDC), followed by invasive lobular carcinoma (ILC). Alternatively, histological grades vary from grades G1 to G3. Therefore, in this study, we evaluated the diagnostic accuracy of frozen section (FS) for detecting breast cancer metastasis to SLNs with respect to histological subtypes and grades. MethodsA retrospective observational study was conducted in the Department of Histopathology at Liaquat National Hospital and Medical College, Pakistan, from January 2013 till December 2020, over a duration of eight years. A total of 540 cases of primary breast cancer, undergoing upfront breast surgery were included in the study. Intraoperatively, SLNs were identified and sent for FS. After FS reporting, the remaining tissue was submitted for final (paraffin) section examination after formalin fixation, and results of FS and final (paraffin) sections were compared. ResultsThe mean age of the patients included in the study was 52.05±12.42 years, and the median number of SLNs was three (ranging from one to 14). The overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of intraoperative FS were 88.2%, 100%, 100%, 92.5%, and 95.2%, respectively. The sensitivity of FS for IDC was 88.3%, whereas it was 85.7% for ILC. Alternatively, the sensitivity of FS for grade G1, G2, and G3 tumors was 78.3%, 91.5%, and 90.2%, respectively. The falsenegative rate for grade G1 tumors was 21.7%, which was higher than G2 and G3 tumors (8.5% and 9.8%, respectively). Similarly, the false-negative rate for cases where the number of SLNs was more than three was only 5.4%, which was lower than cases with a single and two to three SLNs sent on FS (23.1 and 14.7%, respectively). ConclusionThe sensitivity of intraoperative FS for detecting ILC metastasis to axillary SLNs was not substantially different from IDC; however, histological grade affects the sensitivity of FS diagnosis, with lower-grade tumors having low sensitivity. Moreover, increasing the number of SLNs sent intraoperatively on FS improves the sensitivity of FS for detecting breast cancer metastasis to axillary SLNs.

Diagnosis, Prognosis, and Treatment of Canine Hemangiosarcoma: A Review Based on a Consensus Organized by the Brazilian Association of Veterinary Oncology, ABROVET

“…Widely used in human medicine, transoperative histological evaluation by freezing has gained popularity in veterinary medicine and can be used to confirm the diagnosis of cutaneous HSA, as well as to identify neoplastic cells in the lateral and deep surgical margins, helping to determine the extent of the procedure [ 47 , 48 ].…”

Diagnosis, Prognosis and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors

“…In human medicine, the tissue freezing technique is typically used to determine the presence of tumor cells in surgical margins and metastases in sentinel lymph nodes [ 100 , 101 ]. Its accuracy is similar to that of tissues embedded in paraffin [ 102 , 103 ], and this technique can be perforMed.…”

Update on Sentinel Lymph Node Methods and Pathology in Breast Cancer

“…The metastatic disease's size plays a crucial role in influencing the FNR [37,[60][61][62][63][64][65][66][67][68], with reports suggesting an increase of up to eight times in the FNR for micro-metastatic disease versus macro-metastatic disease [63]. Errors in the interpretation of SLN frozen slide analysis are linked with tumor features, including low-grade tumors [59][60][61]69] and lobular histological subtypes [63,64,67,70]. Examining frozen sections of SLNs following neoadjuvant chemotherapy presents a significant challenge, as the cellularity of metastatic deposits is reduced and the alterations caused by the treatment can mask findings.…”