Impact of multisection and immunohistochemistry in lymph node staging of Gastric Carcinoma – Case series

Abstract

Gastric carcinoma (GC) locoregional recurrence may occur even in cases where the tumor has been completely resected, possibly due to lymph node (LN) micrometastases. It is estimated that in 10% to 30% of cases, LN micrometastases are not detected by a conventional method for histological assessment of LN metastases with hematoxylin-eosin (HE). A cross-sectional study assessed 51 patients with GC by histological evaluation of the LN micrometastases through LN multi sectioning associated with immunohistochemistry analysis with monoclonal antibodies AE1 and AE3. Total gastrectomy was performed in 51% of patients. The total number of resected LN nodes was 1698, with a mean number of resected LN of 33.3 ± 13.2 per surgical specimen, of which 187 had metastasis. After the application of LN multisection and immunohistochemistry, LN micrometastases were found in 45.1% of the cases. LN staging changed in 29.4%, and tumor staging changed in 23.5% of the cases. In patients initially staged as pN0, LN staging and tumor staging changed, both in 19.2% of the cases. In patients initially staged as pN1 or more, LN staging changed in 40.0% of them, and tumor staging changed in 28.0% of the cases. The accuracy of HE for the histological staging of LN tumoral involvement was 76%, which was considered insufficient for CG patients staging. Investigation of LN micrometastasis through LN multisection and immunohistochemistry should be performed, particularly in cases where the presence of blood and lymphatic vessel invasion has been identified after conventional histological analysis, as well as in patients with advanced Gc. Gastric carcinoma (GC), despite the recent decrease observed in its incidence, remains the second most common cause of cancer death in the world, with more than 600,000 deaths per year. The main chance of cure of this neoplasm is on surgical resection. The standard procedure for the treatment of this condition is radical gastrectomy, which includes gastric resection with surgical margins free of neoplasia, associated with extended locoregional lymphadenectomy 1-3. Accurate tumor staging is one of the leading factors in the definition of the therapeutic strategy. From the exact knowledge of the extent of tumor dissemination, it is possible to define, with greater security, the best therapeutic approach for each patient, and, consequently, avoid incomplete or excessive treatments 4,5. Recent literature has discussed the role of lymph node (LN) micrometastasis in GC. Conceptually, micrometastases are metastases of sizes between 0.2 mm and 2.0 mm (5). Its incidence varies between 10% to 30% 6,7. Currently, many authors admit that its presence is associated with a worse prognosis and that the clinical behavior of these patients is like those with lymph node involvement by metastasis 8. In the submucosal GC (T1b), with the absence of LN metastases and micrometastases, the five-year survival rate is close to 100%, being significantly higher than in micrometastases positive cases (82%) 6. The presence of micrometastasis ma...

PET/CT for Predicting Occult Lymph Node Metastasis in Gastric Cancer

“…OLNM is defined as a clinical diagnosis of stage N0 that is not detected by conventional palpation and imaging (CT and PET/CT) and lymph node metastasis confirmed by postoperative pathological sections [ 12 , 13 , 14 , 15 ]. The incidence of OLNM in gastric cancer ranges from approximately 11% to 56% [ 16 , 17 , 18 , 19 ]. One study demonstrated that occult metastases were identified in approximately 16% of gastric cancer patients using 18 F-FDG PET/CT [ 20 , 21 , 22 , 23 ].…”