Sentinel lymph node biopsy in esophageal cancer: has its time come?

Endoscopic treatment versus surgical treatment for T1b esophageal cancer: a systematic review and meta-analysis

BACKGROUND

Endoscopic and surgical treatment are the two most common treatment strategies for resectable esophageal cancer (EC), but the optimal treatment for T1b EC remains controversial. This study aims to compare the efficacy and safety of endoscopic treatment versus esophagectomy for T1b EC.

METHODS

Web of Science, MEDLINE, Scopus, and EMBASE were searched from their inception to December 2023. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, we used the fixed- and random-effect models for this meta-analysis by RevMan. The primary outcomes included overall survival (OS), recurrence, lymph node metastasis, complete resection rate and positive resection margin. The secondary outcomes were 1-year survival, 3-year survival, 5-year survival, overall mortality rate, EC-specific mortality rate and lymphovascular invasion.

RESULTS

Nine studies with a population of 1637 patients (endoscopic treatment: 715 patients; surgical treatment: 922 patients) were included. The pooled results showed that surgical treatment was associated with a significantly better OS than endoscopic treatment (Hazard Ratio [HR] = 0.78; 95 % confidence interval [CI]: [0.62, 1.00]; P = 0.05). There was also significant difference in positive resection margin (Relative Risk [RR] = 0.13; 95 % CI: [0.09, 0.20]; P < 0.00001) between the two treatment strategies.

CONCLUSION

The pooled results of this study indicated that surgical treatment had better OS than endoscopic treatment for T1b EC. Furthermore, endoscopic treatment also had significantly higher risk of margin positivity than surgical treatment for T1b EC.

Sentinel node navigation surgery in esophageal cancer

Over the last 20 years, the sentinel node (SN) concept has been widely applied to the surgical staging of both breast cancer and melanoma. However, the validity of this concept has been controversial for esophageal cancer, because SN mapping for esophageal cancer is not considered to be technically easy because of the complicated multidirectional lymphatic networks of the esophagus and mediastinum. Nevertheless, studies including meta-analyses indicated that SN mapping may be feasible in early esophageal cancer. Transthoracic esophagectomy with three-field lymphadenectomy was developed as a potential curative procedure for thoracic esophageal cancer. However, this highly invasive procedure might increase morbidity and reduce patients' quality of life (QOL) after esophagectomy. Although further validation based on multicenter trials using the standard protocol of SN mapping for esophageal cancer is required, SN navigation surgery would enable us to carry out personalized and limited lymph node dissection which might reduce morbidity and maintain patients' QOL.

Sentinel node navigation surgery in early-stage esophageal cancer

The sentinel node (SN) concept has revolutionized the surgical staging of both melanoma and breast cancer over the past two decades. However, the validity of the SN hypothesis has been controversial for esophageal cancer, because SN mapping for esophageal cancer is technically complicated, and the number of early-stage esophageal cancer is very limited. Nevertheless previous studies nicely demonstrated that SN mapping may be feasible in patients with early-stage esophageal cancer. Transthoracic extended esophagectomy with three-field radical lymph node dissection has been recognized as a curative procedure for thoracic esophageal cancer in Japan. However, uniform application of this highly invasive procedure might increase the morbidity and markedly reduce the quality of life (QOL) after surgery. Although further accumulation of evidence based on multicenter clinical trials using a standard protocol is needed, SN mapping and SN navigation surgery would provide significant information to perform individualized selective lymphadenectomy which might reduce the morbidity and retain the patients' QOL. In addition, technical innovation including the development of new tracers is expected to confirm the accuracy and reliability of SN mapping in esophageal cancer.

Sentinel lymph node biopsy in esophageal cancer: should it be standard of care?

INTRODUCTION

Sentinel node mapping is established in some superficial cancers but remains controversial in harder-to-access solid tumors. There are an increasing number of recent studies suggesting that isolated tumor cells have prognostic significance in predicting poor survival, in breast cancer, esophageal cancer, and others. It is for this reason that we have persevered with the sentinel lymph node concept in our esophagectomy cancer patients, and we report our results since 2008.

METHODS

Thirty-one of 32 consecutive patients underwent resection for invasive esophageal cancer along with sentinel lymph node retrieval (resection rate, 97%). Peritumoral injection of (99m)Tc antimony colloid was performed by upper endoscopy prior to the operation. A two-surgeon synchronous approach via a right thoracotomy and laparotomy was performed with a conservative lymphadenectomy. Sentinel lymph nodes were identified with a gamma probe both in and ex vivo, and sent off separately for three serial sections and immunohistochemistry with AE1/AE3.

RESULTS

The median patient age was 63.4 years (range, 45-75 years). Most patients (81%) had an adenocarcinoma, and 61% had received neoadjuvant therapy. At least one sentinel lymph node (median, 3) was identified in 29 of 31 patients (success rate, 94%). Sentinel nodes were present in more than one nodal station in 16 patients (55%). One false negative case led to a sensitivity of 90%. In 28 of 29 patients, the sentinel lymph node accurately predicted findings in non-sentinel nodes (accuracy, 96%).

CONCLUSIONS

Sentinel lymph node biopsy is both feasible and accurate in esophageal resections with conservative lymphadenectomy. It allows targeted serial sectioning and immunohistochemical studies of those nodes and should become standard of care in patients undergoing esophagectomy for esophageal cancer.

Impact of nodal status and tumor burden in sentinel lymph nodes on the clinical outcomes of cancer patients

The validation of sentinel lymph node (SLN) concept in melanoma and breast cancer has established a new paradigm in cancer metastasis that, in general, cancer cells spread in a orderly fashion from the primary site to the SLNs in the regional nodal basin and then to the distant sites. In this review article, we examine the development of SLN concept in penile carcinoma, melanoma and breast carcinoma and its application to other solid cancers with emphasis of the relationship between micrometastasis in SLNs and clinical outcomes.