Sentinel Node Biopsy In Gastric Cancer Research Articles

Current status and challenges in sentinel node navigation surgery for early gastric cancer.

As an optimal surgical procedure to accurately evaluate lymph node (LN) metastasis during surgery with minimal surgical resection, we have been developing sentinel node (SN) biopsy for early gastric cancer since the 1990s. Twelve institutions from the Japanese Society of Sentinel Node Navigation Surgery (SNNS), including Keio University Hospital, conducted a multicenter prospective trial to validate the SN concept using the dual-tracer method with blue dye and a radioisotope. According to the results, 397 patients were included in the final analysis, and the overall accuracy in detecting LN metastasis using SN biopsy was 99% (383 of 387). Based on the validation study, we are targeting cT1N0 with a primary tumor of ≤4 cm in diameter as an indication for SN biopsy for gastric cancer. We are currently running a multicenter nonrandomized phase III trial to assess the safety and efficacy of SN navigation surgery. The Korean group has reported the result of a multicenter randomized phase III trial. Since meticulous gastric cancer in the remnant stomach was rescued by subsequent gastrectomy, the disease-specific survival was comparable between the two techniques, implying that SN navigation surgery can be an alternative to standard gastrectomy. With the development of SN biopsy procedure and treatment modalities, the application of SN biopsy will be expanded to achieve an individualized minimally invasive surgery.

Sentinel node navigation surgery for gastric cancer: Overview and perspective

The sentinel node (SN) technique has been established for the treatment of some types of solid cancers to avoid unnecessary lymphadenectomy. If node disease were diagnosed before surgery, minimal surgery with omission of lymph node dissection would be an option for patients with early gastric cancer. Although SN biopsy has been well ascertained in the treatment of breast cancer and melanoma, SN navigation surgery (SNNS) in gastric cancer has not been yet universal due to the complicated lymphatic flow from the stomach. Satisfactory establishment of SNNS will result in the possible indication of minimally invasive surgery of gastric cancer. However, the results reported in the literature on SN biopsy in gastric cancer are widely divergent and many issues are still to be resolved, such as the collection method of SN, detection of micrometastasis in SN, and clinical benefit. The difference in the procedural technique and learning phase of surgeons is also varied the accuracy of SN mapping. In this review, we outline the current status of application for SNNS in gastric cancer.

Sentinel Node Biopsy in Early Gastric Cancer: Constant Exertion for Clinical Application

Lymph node status is the most important prognostic factor in gastric cancer. Standard surgery, therefore, is radical subtotal or total gastrectomy with wide dissection of regional lymph nodes. Recently, the proportion of early gastric cancer has increased to more than 60% in Korea and Japan because of screening gastroscopy. The rate of lymph node metastasis in early gastric cancer ranges from 5 to 20%, which means that more than 80% of patients with early gastric cancer undergo unnecessarily wide excision of the stomach with aggressive lymphadenectomy. If there is a tool to predict the exact status of lymph nodes, radical gastrectomy with lymphadenectomy can be substituted with limited resection of stomach without lymph node dissection. However, preoperative endoscopic ultrasound and computed tomography have limited accuracy for nodal staging in gastric cancer patients. The sentinel node (SN) concept has been introduced into various solid tumors, including stomach cancer, to predict lymph node status. Ideally, if the SN has no metastasis, extensive lymphadenectomy can be avoided, the extent of resection of the stomach reduced, function preserved, complications lessened, recovery accelerated, and the quality of life for the patient improved. SN navigation surgery has been widely performed for the treatment of breast cancer and malignant melanoma. Regarding gastric cancer, it seemed that SN concept is difficult to apply because the lymphatic flow is multidirectional. However, many studies reported that SN mapping is feasible in gastric cancer especially in early gastric cancer even though many issues still remain to be solved. Sensitivity of SN biopsy is highly important in gastric cancer compared with breast cancer and malignant melanoma. When false-negative cases develop in patients with malignant melanoma or breast cancer, other treatment options, such as chemotherapy and radiotherapy exist. Because gastric cancer has no other treatment option except surgery, a gastric cancer patient with false-negative SN loses an opportunity for cure. The detection rate is not as important as sensitivity in gastric cancer SN biopsy. Surgeons should perform just conventional lymphadenectomy for detection failure cases. Sensitivities of SN mapping in gastric cancer reported until now are not adequate for clinical application. Until now, the sensitivities were generally low and even the studies with high sensitivity had small number of cases with lymph node metastasis. There are several methods to increase the sensitivity of SN biopsy in gastric cancer. As pathologic methods, multiple sections of the SN may raise the rate of detecting lymph node metastases. Immunohistochemistry (IHC) staining with anti-cytokeratin antibody helps to detect micrometastases in SNs in addition to conventional hematoxylin and eosin (HE) staining. Reverse transcription-polymerase chain reaction (RT-PCR) using tumor markers, such as carcinoembryonic antigen, cytokeratin, or CD44, also is good tool for molecular detection of SN micrometastases. Rapid IHC or real-time RT-PCR is needed so that IHC or RT-PCR is applicable to SN biopsy for gastric cancer. Takeuchi et al. 1 introduced a novel realtime multiplex RT-PCR assay that is suitable for intraoperative detection of micrometastasis in SNs for the patients with clinical N0 gastric carcinoma. In the present study, 31% of patients with no metastasis over histological diagnosis were RT-PCR positive and the diagnostic accuracy is significantly higher in their multiplex RT-PCR assay than in intraoperative histopathology. Because the time taken for the assay is just 80 minutes, real-time multiplex RT-PCR is thought to be applicable for use in the intraoperative diagnosis of SN. Society of Surgical Oncology 2011

Comparative study of the subserosal versus submucosal dye injection method for sentinel node biopsy in gastric cancer

Aims To determine the most efficient injection method for a sentinel node (SN) biopsy in gastric cancer. Methods Gastric adenocarcinoma patients without serosal invasion and distant metastasis were prospectively enrolled in this study. Isosulfan blue was injected into the subserosa (SS) of the first set of 71 consecutive patients and an intraoperative endoscopic submucosal (SM) injection of the same dye was injected into the second set of 50 consecutive patients. After the biopsy of blue-stained SNs, a gastrectomy with a D2 lymphadenectomy was performed. All dissected lymph nodes were evaluated for metastasis. The results of the SN biopsies were compared between the SS and SM dye injection methods. Results Detection rate (0.92 vs 0.94), mean number of SNs (2.5 vs 2.9) and sensitivity (0.61 vs 0.46) of the SN biopsies were not significantly different between the SS and SM injection methods ( P>0.05). The operation time was significantly shorter in the SS than the SM injection method (159.7 vs 172.7 min, P=0.030). Conclusions Both injection methods were equally efficient in their roles for a SN biopsy in gastric cancer. However, the SS injection method was more preferable due to its easy technique and short operation time.