Status of sentinel lymph node biopsy in gynecological cancers

Sentinel Lymph Node Assessment in Endometrial Cancer: A Review

As the number of patients diagnosed with endometrial cancer rises, so does the number of patients who undergo surgical treatment, consisting of radical hysterectomy, bilateral salpingo-oophorectomy, and bilateral pelvic lymphadenectomy or lymph node sampling. The latter entail intra- and post-surgical complications, such as lymphedema and increased intra-operative bleeding, which often outweigh their benefits. Sentinel Lymph Node (SLN) sampling is now common practice in surgical management of breast cancer, as it provides important information about the disease without jeopardizing surgical radicality and patient outcomes. While this technique has also been shown to be feasible in patients with endometrial cancer, there is little consensus on several aspects, such as tracer injection volume and site, pathological ultrastaging, and result interpretation. The aim of this review is to analyze the current literature on SLN assessment in order to help standardize the procedure.

A new label-free optical imaging method for the lymphatic system enhanced by deep learning

Our understanding of the lymphatic vascular system lags far behind that of the blood vascular system, limited by available imaging technologies. We present a label-free optical imaging method that visualizes the lymphatic system with high contrast. We developed an orthogonal polarization imaging (OPI) in the shortwave infrared range (SWIR) and imaged both lymph nodes and lymphatic vessels of mice and rats in vivo through intact skin, as well as human mesenteric lymph nodes in colectomy specimens. By integrating SWIR-OPI with U-Net, a deep learning image segmentation algorithm, we automated the lymph node size measurement process. Changes in lymph nodes in response to cancer progression were monitored in two separate mouse cancer models, through which we obtained insights into pre-metastatic niches and correlation between lymph node masses and many important biomarkers. In a human pilot study, we demonstrated the effectiveness of SWIR-OPI to detect human lymph nodes in real time with clinical colectomy specimens.

One Sentence Summary

We develop a real-time high contrast optical technique for imaging the lymphatic system, and apply it to anatomical pathology gross examination in a clinical setting, as well as real-time monitoring of tumor microenvironment in animal studies.

Applications and Safety of Sentinel Lymph Node Biopsy in Endometrial Cancer

Lymph node status is important in predicting the prognosis and guiding adjuvant treatment in endometrial cancer. However, previous studies showed that systematic lymphadenectomy conferred no therapeutic values in clinically early-stage endometrial cancer but might lead to substantial morbidity and impact on the quality of life of the patients. The sentinel lymph node is the first lymph node that tumor cells drain to, and sentinel lymph node biopsy has emerged as an acceptable alternative to full lymphadenectomy in both low-risk and high-risk endometrial cancer. Evidence has demonstrated a high detection rate, sensitivity and negative predictive value of sentinel lymph node biopsy. It can also reduce surgical morbidity and improve the detection of lymph node metastases compared with systematic lymphadenectomy. This review summarizes the current techniques of sentinel lymph node mapping, the applications and oncological outcomes of sentinel lymph node biopsy in low-risk and high-risk endometrial cancer, and the management of isolated tumor cells in sentinel lymph nodes. We also illustrate a revised sentinel lymph node biopsy algorithm and advocate to repeat the tracer injection and explore the presacral and paraaortic areas if sentinel lymph nodes are not found in the hemipelvis.

Nerve-oriented mesorectal excision (NOME): autonomic nerves as landmarks for laparoscopic rectal resection

PURPOSE

We have developed nerve-oriented mesorectal excision (NOME) as a novel concept in rectal cancer surgery by which autonomic pelvic nerves serve as landmarks for a standardized navigation along fascial planes. This article describes the technique step by step and presents our results from 2008 to 2012.

MATERIAL AND METHODS

The key steps are: preparation of the splanchnic nerves at the mid-posterior sidewall, the hypogastric nerves at the upper sidewall, and the urogenital nerve branches (Walsh) at the caudal-anterior sidewall. The dissection of the lateral ligament is strictly performed as the last step. NOME was applied in 274 consecutive mesorectal excisions (partial 20.4%, total 79.6%); a subgroup of 42 male patients underwent a questionnaire-based interview on sexual activity.

RESULTS

The conversion rate was 0.7%. High (complete) specimen quality and circumferential margin negativity were achieved in 90.1% and 95.3%, respectively. Anastomotic leaks occurred in 13 (4.7%) patients. Mortality was 1.8%. The frequency of prolonged urinary catheter was 1.8%. Of 22 sexually active males interviewed, 18 (81.8%) maintained activity postoperatively.

CONCLUSIONS

NOME achieves high-quality mesorectal specimens and a high rate of preservation of autonomic nerve function. The concept of using nerves as laparoscopic landmarks may help to standardize and master laparoscopic rectal cancer surgery.

Added-value of SPECT/CT to lymphatic mapping and sentinel lymphadenectomy in gynaecological cancers

Lymphatic mapping and sentinel lymphadenectomy (LM/SL) have been successfully used in pre-treatment nodal staging of gynaecological cancers. We hypothesised the added-value of LM/SL plus SPECT/CT in patients with early stage of cervical cancer and vulvar cancer. A prospective, single-center, diagnostic, open label, active control, non-randomized clinical trial has been conducted in 7 patients with FIGO IA-IB1 cervical cancer and 7 patients with FIGO stage I-II-IIIcN0 vulvar cancer. All patients underwent LM/SL plus SPECT/low-dose CT and complete lymph node dissection (CLND) according to the standard of care. In case of negative hematoxylin-eosin staining, serial sections of the SLNs were analysed by immunohistochemistry and high molecular weight cytokeratin. Primary outcome measures were the detection rate, the sensitivity (SV), the negative predictive value (NPV), the diagnostic accuracy (DA) for anatomic localisation of SLNs, and the impact on management of SPECT/CT guided LM/SL versus CLND. The secondary outcome measure was the patient tolerability and operating time of LM/SL guided SPECT/CT versus CLND. http://clinicaltrials.gov/show/NCT00773071 All 14 patients were enrolled into the 1-day research protocol with dual-tracer LM/SL and SPECT/CT. Additional SLNs were detected on SPECT/CT compared to conventional planar imaging. Hot and cold > 1cm SLNs were detected on SPECT/CT. Detection rate, SV, NPV, DA were 100% in both groups; false negative rate was 0%. Rate of SLN metastases was 28.5% in cervical cancer and 42.9% in vulvar cancer. Impact on treatment was 28.5% and 14.3% in cervical cancer and vulvar cancer patients, respectively. SPECT/CT was well tolerated by all patients and operating time for LM/SL was within 30 min. No adverse events were reported with a time frame of 1-to-3 years. In early stage of gynaecological cancers, SPECT/low-dose CT is technically feasible and of clinical added-value for LM/SL.

Trop-2 protein overexpression is an independent marker for predicting disease recurrence in endometrioid endometrial carcinoma

Background

Endometrial cancer is the most common gynecologic malignancy in developed countries. Trop-2 is a glycoprotein involved in cellular signal transduction and is differentially overexpressed relative to normal tissue in a variety of human adenocarcinomas, including endometrioid endometrial carcinomas (EEC). Trop-2 overexpression has been proposed as a marker for biologically aggressive tumor phenotypes.

Methods

Trop-2 protein expression was quantified using tissue microarrays consisting of formalin-fixed paraffin-embedded specimens from 118 patients who underwent surgical staging from 2001–9 by laparotomy for EEC. Clinicopathologic characteristics including age, stage, grade, lymphovascular space invasion, and medical comorbidities were correlated with immunostaining score. Univariate and multivariate analyses were performed for overall survival, disease-free survival, and progression-free survival in relation to clinical parameters and Trop-2 protein expression.

Results

Clinical outcome data were available for 103 patients. Strong Trop-2 immunostaining was significantly associated with higher tumor grade (p=0.02) and cervical involvement (p<0.01). Univariate analyses showed a significant association with reduced disease-free survival (DFS) (p=0.01), and a trend towards significance for overall and progression-free survival (p=0.06 and p=0.05, respectively). Multivariate analyses revealed Trop-2 overexpression and advanced FIGO stage to be independent prognostic factors for poor DFS (p=0.04 and p <0.001, respectively).

Conclusions

Trop-2 protein overexpression is significantly associated with higher tumor grade and serves as an independent prognostic factor for DFS in endometrioid endometrial 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.

Staging of gynaecological malignancies by natural orifice transluminal endoscopic surgery (N.O.T.E.S.)

Gynaecological malignancies are most often diagnosed and staged by surgery. With the expanding evidence of efficacy and benefit of neoadjuvant treatments, such tumor confirmation and assessment should be ideally done with the least associated morbidity. Thus sentinel node biopsy has already been proposed for selected indications so that the morbidity associated with formal lymphadenectomy could be avoided in those patients without nodal metastases. The era of natural orifice transluminal endoscopic surgery (N.O.T.E.S.) heralds an operative methodology of 'least invasiveness' that could be useful in gynaecological cancer. In this article, we present an overview of the staging of gynaecological malignancies with a focus on the potential applications and benefits that N.O.T.E.S. may provide in this field. In particular, we believe that performing sentinel lymph node dissection with N.O.T.E.S. could associate the low morbidity rate of the former technique with the minimal invasiveness of the latter one and therefore consolidate the potential of this technique.