Clinical significance of circulating tumor cells in peripheral blood from patients with gastric cancer.

BACKGROUND: The authors hypothesized that circulating tumor cells (CTCs) in patients with gastric cancer are associated with prognosis and disease recurrence. In this study, they evaluated CTCs in gastric cancer and clarified the clinical impact of CTCs. METHODS: In total, 265 consecutive patients with gastric cancer were enrolled. Fourteen patients were excluded from the analysis, including 12 patients who another cancer and 2 patients who refused the treatment. The remaining 251 patients were divided into 2 groups: 148 patients who underwent gastrectomy (the resection group) and 103 patients who did not undergo gastrectomy (the nonresectable group). Peripheral blood samples were collected before gastrectomy or chemotherapy. A proprietary test for capturing, identifying, and counting CTCs in blood was used for the isolation and enumeration of CTCs. RESULTS: CTCs were detected in 16 patients (10.8%) from the resection group and in 62 patients (60.2%) from the nonresectable group. The overall survival rate for the entire cohort was significantly lower in patients with CTCs than in those without CTCs (P < .0001). In the resection group, relapse-free and overall survival in patients with CTCs was significantly lower than in patients without CTCs (P < .0001). It was noteworthy that the expression of CTCs was an independent factor for determining the overall survival of patients with gastric cancer in multivariate analysis (P = .024). In the nonresectable group, the overall survival rate was significantly lower in patients with CTCs than in those without CTCs (P = .0044). CONCLUSIONS: The evaluation of CTCs in peripheral blood may be a useful tool for predicting tumor progression, prognosis, and the effect of chemotherapy in patients with gastric cancer.

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

PURPOSE: The clinical significance of lymph node micrometastasis remains unclear in patients with esophageal cancer. Therefore, accurate assessment of lymph node status including micrometastasis is important when performing sentinel node (SN) navigation surgery. The purpose of the present study was to investigate the adequacy of SN concept based on lymph node micrometastasis determined by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) in patients with esophageal cancer. METHODS: A total of 57 patients with esophageal cancer who were preoperatively diagnosed as having T1-T2 (cT1-T2) and N0 (cN0) were enrolled. They underwent standard esophagectomy with lymph node dissection. One day before surgery, a total of 3 mCi of 99mTechnetium-tin colloid was endoscopically injected into the submucosa around the tumor. During the operation, radioisotope uptake in the lymph nodes was measured using Navigator GPS. All dissected lymph nodes were investigated by RT-PCR using the double marker of CEA and SCC, hematoxylin-eosin (HE) staining, and IHC. RESULTS: Node-positive incidence identified by HE and IHC was 12.3% (7/57) and 19.3% (11/57), respectively. RT-PCR demonstrated micrometastasis in four of 46 patients without nodal metastasis determined by HE staining and IHC. No non-SN metastases were found in 42 patients without micrometastasis identified by IHC and RT-PCR of SN. Accuracy and false negative rates were 100% (57/57) and 0% (0/42), respectively. CONCLUSIONS: SN concept might be acceptable in patients with cT1-T2 and cN0 esophageal cancer, even in the presence of micrometastasis identified by IHC and RT-PCR.

Sentinel node navigation surgery is acceptable for clinical T1 and N0 esophageal cancer.

BACKGROUND: If the sentinel node (SN) concept is established for esophageal cancer, it will be possible to reduce safely the extent of lymphadenectomy. Our objective was to perform SN mapping in esophageal cancer to assess distribution of lymph node metastases with the goal to reduce the need for extensive lymphadenectomy. METHODS: A total of 134 patients who underwent esophagectomy with lymph node dissection were enrolled. The number of patients with clinical T1, T2, and T3 tumors was 60, 31, and 32, respectively. Eleven patients also received neoadjuvant chemoradiation therapy (CRT). (99m)Tc-Tin colloid was injected endoscopically into the esophageal wall around the tumor 1 day before surgery. SNs were identified by using radioisotope (RI) uptake. RI uptake of all dissected lymph nodes was measured during and after surgery. Lymph node metastases, including micrometastases, were confirmed by hematoxylin eosin and immunohistochemical staining. RESULTS: Detection rates of SNs were 93.3% in cT1, 100% in cT2, 87.5% in cT3, and 45.5% in CRT patients. In the 120 cases where SNs were identified, lymph node metastases were found in 12 patients with cT1, 18 with cT2, 24 with cT3 tumors, and 3 with CRT. Accuracy rate of SN mapping was 98.2% in cT1, 80.6% in cT2, 60.7% in cT3, and 40% in CRT patients. Although one false-negative case had cT1 tumor, the lymph node metastasis was detected preoperatively. CONCLUSIONS: SN mapping can be applied to patients with cT1 and cN0 esophageal cancer. SN concept might enable to perform less invasive surgery with reduction of lymphadenectomy.

The utility of rapid diagnosis of lymph node metastasis in gastric cancer using a multiplex real-time reverse transcription polymerase chain reaction assay.

BACKGROUND: Lymph node metastasis is the most important prognostic factor in gastric cancer. However, diagnosis by hematoxylin and eosin staining or immunohistochemistry is not always sufficient for the detection of cancer cells because only representative number of slices are examined. Cancer cells may, therefore, be missed by traditional histological methods. Recently, reverse transcription polymerase chain reaction (RT-PCR) methods have been introduced for improved detection of cancer cells. The purpose of this study was to evaluate the utility of a prototype RT-PCR assay run on the Cepheid SmartCycler system compared to conventional RT-PCR using the LightCycler system. PATIENTS AND METHODS: Forty-seven overt metastatic lymph nodes from 8 patients with advanced gastric cancer and 22 benign lymph nodes from patients without malignant tumor who received surgery were obtained with informed consent. We examined the lymph nodes by RT-PCR, using markers for CEA and CK19 and the LightCycler and SmartCycler systems. RESULTS: In the singlex assay, the sensitivity of CEA and CK19 was 91.5 and 70.2% in the LightCycler system, and 97.9 and 95.7% in the SmartCycler system, respectively. In the multiplex assay, the sensitivity was 91.5% in the LightCycler system and 100% in the SmartCycler system, respectively. CONCLUSION: In this study, rapid diagnosis using RT-PCR by the SmartCycler system had higher accuracy for detecting lymph node metastasis than the conventional LightCycler system. The SmartCycler system is more effective for the diagnosis of lymph node metastasis in gastric cancer when run with the prototype assay.

Detection of micrometastases in sentinel node navigation surgery for gastric cancer.

Although lymph node metastasis is one of the important prognostic factors for patients with gastric cancer, the clinical significance of micrometastasis remains controversial. In the 6th edition of the TMN classification, micrometastases were classified as micrometastasis (MM) and isolated tumor cells (ITC) according to its greatest dimension. The accurate diagnosis of micrometastases is required when considering less invasive surgery, especially in early stage of gastric cancer. Since generating useful information about micrometastases by conventional RT-PCR is time-consuming, this procedure is not useful for rapid diagnosis during surgery. Recently some new methods of genetic diagnosis have reduced the amount of time required to obtain information about micrometastases in lymph nodes to 30-40 min. Such methodology can be clinically applied during less invasive surgery. The sentinel node (SN) concept has recently been applied to gastric cancer and SN navigation surgery (SNNS) is ideal for reduction of lymphadenectomy in patients with early gastric cancer. However, we should think about some conditions to establish SN concept for gastric cancer: the particle size of radioisotope, relationship between metastatic area and RI uptake, and the diagnosis of micrometastases by various method such as histological examination, immunostaining and RT-PCR. Here, we described the current status of MM and ITC in the lymph nodes and the SN concept in gastric cancer.

Intramammary sentinel lymph node in patients with breast cancer: report of four cases.

To analyze breast cancer patients with intramammary sentinel lymph node, we reviewed T1-T2N0 breast cancer patients who underwent sentinel lymph node mapping using radioisotope methods. Intramammary sentinel lymph (ISN) nodes were detected in 4 of 166 patients. Three of four ISNs were present in completely different quadrants of the breast from those of primary lesions. Although two patients had no involved nodes, including ISNs, the remaining two with T2 tumor had metastasis of ISNs alone with resulting upstaging. We should keep in mind the presence of intramammary SN in regions apart from the primary tumor, particularly when performing breast conservative surgery.

Analysis of T-helper type 1 and 2 cells and T-cytotoxic type 1 and 2 cells of sentinel lymph nodes in breast cancer.

The immune suppression of sentinel lymph node (SN) is directly influenced by primary tumors. It has been reported that the T-helper type 1 (Th1) to T-helper type 2 (Th2) ratio or T-cytotoxic type 1 (Tc1) to T-cytotoxic type 2 (Tc2) ratio of lymph node lymphocytes could be used to evaluate direct immunological circumstances. We attempted to evaluate the Th1 to Th2 cell and Tc1 to Tc2 cell balance in SN and non-SN and to clarify the immunological status of sentinel nodes in breast cancer. To evaluate this balance, SN and non-SN were identified by radioguided methods and lymph node lymphocytes were collected, and prepared for flow cytometry. The Th1 to Th2 and Tc1 to Tc2 ratio were calculated by 3-color flow cytometry. The ratio of SN and non-SN was compared. The results demonstrated that SN was detected in 24 out of 24 patients (100%). As regards the correlation between SN and non-SN in the same patients, the Th1 to Th2 ratio in SN was significantly lower than that in non-SN for all patients (p<0.05). Among clinicopathological factors, a larger tumor diameter, histology and nodal involvement affected the decreased Th1 to Th2 ratio in SN significantly (p<0.05). We reached the conclusion that the increasing immunosuppressive conditions derived from the tumor may deteriorate the Th1 to Th2 ratio of SN in an earlier stage as compared with non-SN. According to the tumor extension and nodal involvement, the Th1 to Th2 ratio in SN was significantly suppressed. The current result supports that mainly helper T-cell paralysis occurred first in SN and this seems to be a favorable condition in forming lymph node metastases in SN. Moreover, the immunologic interaction between the primary site and regional lymph nodes may serve as useful criteria for identifying sentinel nodes.

Morphological distribution of metastatic foci in sentinel lymph nodes with gastric cancer.

BACKGROUND: The TNM classification defines micrometastasis (MM) and isolated tumor cells (ITC) in lymph nodes (LN). Sentinel node (SN) navigation surgery has been introduced in gastrointestinal cancer. Few reports have examined the morphological distribution of MM and ITC of SN in gastric cancer. The purpose of this study was to clarify the clinical significance of the morphological distribution of cancer cells in SNs according to metastasis (MA), MM, and ITC. METHODS: All dissected LNs obtained from 160 consecutive patients with mapped SNs arising from cT1-2 N0 tumors were examined. Metastasis in these LNs was examined by histology and cytokeratin staining. The distribution of MA, MM, and ITC was classified as marginal sinus (MS), intermediate sinus (IS), parenchymal (PA), and diffuse types (DF). RESULTS: Nodal metastases were detected in 65 SNs from 30 patients and MA, MM, and ITC accounted for 53.9%, 21.5%, and 24.6%, respectively. MS, IS, PA, and DF accounted for 57%, 6%, 17%, and 20.0%, respectively. Patients with metastasis of non-MS had more nodal metastasis in non-SNs (P = .025) and had nodal metastasis in second tier (P = .009), compared with the patients with metastasis of MS. The incidence of metastasis in non-MS was higher in tumors larger than 40 mm than those smaller than 40 mm (P = .011). CONCLUSION: When performing SN navigation surgery in gastric cancer, we should keep in mind that the patients with tumor larger than 40 mm in size and nodal metastasis of non-MS may have non-SN metastasis and nodal metastasis in second tier.

Sentinel node micrometastases have high proliferative potential in gastric cancer.

BACKGROUND: The 6th edition of the TNM classification has recently defined "sentinel nodes (SN)," "micrometastasis," and "isolated tumor cells (ITC)." The present study examines the frequency and proliferative activity of such metastases with focus on the SNs of gastric cancer. METHODS: We enrolled 133 patients with cT1-2 tumors (cT1: 104, cT2: 29) and mapped SNs. Lymph node metastases were examined by routine histology and by immunohistochemistry with anti-cytokeratin. We used the Ki-67 antibody to detect the primary tumor and lymph node metastases to evaluate proliferative activity. RESULTS: The number of patients with SNs metastases and metastatic SNs was 19 and 52, respectively. The frequencies of macrometastasis, micrometastasis, and ITC were 48%, 25%, and 27%, respectively. Ki-67 expression in the tumor closely correlated with lymphatic invasion (P = 0.0001), venous invasion (P < 0.0001), and lymph node metastasis (P < 0.0001). Cells in 96% of macrometastases, 92% of micrometastases, and 29% of ITCs were Ki-67 positive. CONCLUSIONS: We showed that micrometastasis and some ITCs in SNs had proliferative activity. We suggest that micrometastasis and ITCs should be removed, especially during SN navigation surgery, until their clinical significance is clarified.