Assessment of sentinel node concept in esophageal cancer based on lymph node micrometastasis

Roles of Pathological Assessments of Frozen Sections in Esophageal Squamous Cell Carcinoma

Pathological assessment of frozen sections of tissues is important in the clinical management (intraoperative consultation) and research in patients with esophageal squamous cell carcinoma. Frozen sections may be used in the assessment of status of resection margins, extent of cancer metastasis (pathological staging), confirmation of the pathology, and increased volume of cancer cells for tissue banking. However, the applications of frozen sections have many technical limitations. Thus, interpretation of frozen sections needs expertise, collaborations, and attention to proper technical skills in the sectioning.

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

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.

Prognostic Significance of "Nonsolid" Microscopic Metastasis in Merkel Cell Carcinoma Sentinel Lymph Nodes

Our recent work regarding Merkel cell carcinoma sentinel lymph node (SLN) metastasis found that "solid" pattern microscopic metastasis conferred worse prognosis than the "nonsolid" ones. The goals of the present study were to (1) compare the prognostic significance/outcomes of 2 diagnostic groups-patients with a nonsolid pattern of SLN metastasis and those with diagnostically negative SLN biopsies (SLNB), and (2) evaluate the durability of SLN metastasis after extensive sectioning. Five-level, step-wise sectioning at 250-μm intervals was performed in all SLN blocks with an immunohistochemical stain for CK20 on all levels. The presence and pattern of metastases were recorded and analyzed as were corresponding patient and tumor parameters. Median follow-up durations for all patients (n=38), positive SLNB (n=16) and negative SLNB (n=22) groups were 56.3, 50.4, and 66.8 months, respectively. Overall survival (OS) and disease-specific survival (DSS) did not differ between the 2 diagnostic groups (OS P=0.65, DSS P=0.37) but did differ by immune status (immunocompetent vs. immunosuppressed, OS P=0.03, DSS P=0.005) and primary tumor category (OS P<0.0001, DSS P=0.001). On deeper sectioning, all 16 diagnostically positive SLNB continued to show nonsolid microscopic metastasis, and 32% (7/22) diagnostically negative SLNB revealed nonsolid metastasis. DSS was worse for sinusoidal-pattern metastasis versus all others (P=0.02). Five of 38 patients (13%) died of disease; the only immunocompetent patient had sinusoidal-pattern metastasis discovered in a diagnostically negative SLNB. Our data suggest that outcome for nonsolid metastasis is similar to that of negative SLNB with the exception of the sinusoidal pattern, which was associated with worse outcome. Larger studies are warranted to quantify and compare microscopic metastatic tumor burden by pattern and confirm whether the sinusoidal pattern confers an intermediate prognostic risk between solid and other nonsolid microscopic metastases.

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.

Pilot-study on the feasibility of sentinel node navigation surgery in combination with thoracolaparoscopic lymphadenectomy without esophagectomy in early esophageal adenocarcinoma patients

High-risk submucosal esophageal adenocarcinoma's might be treated curatively by means of radical endoscopic resection, followed by thoracolaparoscopic lymphadenectomy without concomitant esophagectomy. A preclinical study has shown the feasibility and safety of this approach; however, no studies are performed in a clinical setting. In addition, sentinel node navigation surgery could be valuable in tailoring the extent of the lymphadenectomy. This study aimed to evaluate the feasibility and safety of thoracolaparoscopic lymphadenectomy without esophagectomy (phase I) and sentinel node navigation surgery (phase II) in patients with early esophageal adenocarcinoma. Patients with T1N0M0 early esophageal adenocarcinoma scheduled for esophagectomy without neoadjuvant therapy were included. Phase I: Two-field, esophagus preserving, thoracolaparoscopic lymphadenectomy was performed, followed by esophagectomy in the same session. Primary outcome parameters were the number of lymph nodes resected, and number of retained lymph nodes in the esophagectomy specimen. Phase II: A radioactive tracer was injected endoscopically the day before surgery. Static imaging was performed 15 and 120 minutes after injection. The day of surgery, sentinel node navigation surgery followed by esophagectomy was performed. Primary outcome parameters were the percentage of patients with a detectable sentinel node, and the concordance between static imaging and probe-based detection of sentinel node. Phase I: Five patients were included, and a median of 30 (IQR: 25-46) lymph nodes was resected. A median of 6 (IQR: 2-9) retained lymph nodes was found in the esophagectomy specimen. No acute adverse events occurred, but near the end of lymphadenectomy esophageal discoloration was observed, possibly indicating ischemia. Phase II: In all five included patients sentinel nodes could be visualized and resected, at a median of 3 (IQR: 2-5) locations. There was a high concordance between imaging and probe-based detection of sentinel nodes. In conclusion, sentinel node navigation surgery followed by lymphadenectomy without concomitant esophagectomy seems feasible in patients with high-risk submucosal early esophageal adenocarcinoma. More evidence is however needed before applying this technique in clinical practice.

The Prevalence of Overall and Initial Lymph Node Metastases in Clinical T1N0 Thoracic Esophageal Cancer: From the Results of JCOG0502, a Prospective Multicenter Study

OBJECTIVE

To evaluate the sites and frequencies of overall and initial lymph node (LN) metastases (LNMs) of clinical T1N0 esophageal cancer.

BACKGROUND

The sites and frequencies of initial LNMs and sentinel LNs (SLNs) of esophageal cancer remain unclear.

METHODS

The Japan Clinical Oncology Group JCOG0502 trial was a 4-arm prospective study that compared esophagectomy with chemoradiotherapy for clinical T1N0 esophageal cancer in both randomized and patient-preference arms. The preoperative diagnostic accuracy was evaluated for patients assigned to the surgery arm. Patients who withdrew consent and who were not treated were excluded. All patients underwent esophagectomy with D2 or greater LN dissection. From the pathologic findings, sites and frequencies of LNMs and SLNs were assessed and the frequency of skip LNMs was calculated.

RESULTS

In total, 211 patients underwent LNM and SLN analysis. Regarding N-factor accuracy, 57 (27.0%) of 211 clinical N0 cases had pathologic LNMs. The upper mediastinal and mediastinal/abdominal regions were frequent sites of LNMs in upper and lower thoracic cases, respectively. However, in middle thoracic cases, LNMs were observed in the neck, mediastinal, and abdominal regions, and pathologic SLN spread to all 3 fields. The frequency of skip LNMs was 36.7%.

CONCLUSIONS

A clinical diagnosis of T1N0 is not sufficiently accurate, and therefore, it is unacceptable to omit LN dissection or minimize the prophylactic radiation field. SLNs, which are not location restricted, should be surveyed in all 3 fields.

Clinical Significance of Circulating Tumor Cells in Peripheral Blood of Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND

Esophageal squamous cell carcinoma is an aggressive gastrointestinal tract cancer. To date, the presence of circulating tumor cells (CTC) has been reported as a prognostic factor in peripheral blood from patients with gastrointestinal cancers.

METHODS

The CellSearch system was used to isolate and enumerate CTCs. A total of 90 patients with esophageal squamous cell carcinoma who received chemotherapy or chemoradiotherapy were enrolled. Peripheral blood specimens were collected before and after treatments.

RESULTS

At baseline analysis, CTCs were detected in 25 patients (27.8 %). Overall survival was significantly shorter in patients with than without CTCs. Follow-up blood specimens were obtained from 71 patients. Partial response, stable disease, and progressive disease after treatment were seen in 32, 12, and 27 patients, respectively. CTC positivity after treatment in the progressive disease group (40.7 %) was significantly higher than that of the partial response group (6.3 %). Patients with a change in CTC status from positive to negative had a good prognosis as well as patients without baseline CTCs.

CONCLUSIONS

Evaluation of CTCs may be a promising indicator for predicting tumor prognosis and the clinical efficacy of chemotherapy or chemoradiation therapy in patients with esophageal squamous cell carcinoma.

Lymph node micrometastasis in gastrointestinal tract cancer--a clinical aspect

Lymph node micrometastasis (LNM) can now be detected thanks to the development of various biological methods such as immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). Although several reports have examined LNM in various carcinomas, including gastrointestinal (GI) cancer, the clinical significance of LNM remains controversial. Clinically, the presence of LNM is particularly important in patients without nodal metastasis on routine histological examination (pN0), because patients with pN0 but with LNM already in fact have metastatic potential. However, at present, several technical obstacles are impeding the detection of LNM using methods such as IHC or RT-PCR. Accurate evaluation should be carried out using the same antibody or primer and the same technique in a large number of patients. The clinical importance of the difference between LNM and isolated tumor cells (≤0.2 mm in diameter) will also be gradually clarified. It is important that the results of basic studies on LNM are prospectively introduced into the clinical field. Rapid diagnosis of LNM using IHC and RT-PCR during surgery would be clinically useful. Currently, minimally invasive treatments such as endoscopic submucosal dissection and laparoscopic surgery with individualized lymphadenectomy are increasingly being performed. Accurate diagnosis of LNM would clarify issues of curability and safety when performing such treatments. In the near future, individualized lymphadenectomy will develop based on the establishment of rapid, accurate diagnosis of LNM.