Molecular diagnosis of lymph node metastasis in patients with upper urinary tract cancer who underwent lymphadenectomy

Septin 9 methylation analysis of lymph node micrometastases for predicting relapse of colorectal cancer

BACKGROUND

Molecular markers for the detection of lymph node micrometastases of malignant tumors have been extensively investigated. However, epigenetic signatures have rarely been reported for identification of metastatic lymph nodes and disease relapse. Septin 9 is the most frequently reported hypermethylated gene in colorectal cancer (CRC). This study aimed to assess the clinical relevance of Septin 9 methylation in regional lymph nodes in recurrence/metastases of CRC.

METHODS

We analyzed Septin 9 methylation of DNA from resected lymph nodes in 75 CRC patients with or without tumor recurrence using quantitative methylation-sensitive PCR (qMS-PCR).

RESULTS

Of the 30 histologically negative lymph node CRC patients without recurrence (group 1), methylated Septin 9 was detected in 3 (10 %) cases. The positivity rate of methylated Septin 9 in group 2 containing 30 histologically node-negative CRC patients with recurrence was 30 % (9/30). For group 3, lymphatic invasion as well as tumor recurrence, 11 (73 %) out of 15 subjects had Septin 9 methylation-positive lymph nodes. Moreover, patients in group 3 had a higher level of methylated Septin 9 compared to subjects in group 1 and group 2 (p < 0.05). In addition, CRC patients with Septin 9 methylation in lymph nodes had significantly reduced survival (Log-rank P < 0.0001).

CONCLUSION

Our data support the predictive role of Septin 9 methylation analysis of lymph node micrometastases for tumor relapse after surgery.

Oncologic outcomes of laparoscopic radical nephroureterectomy in conjunction with template-based lymph node dissection: An extended follow-up study

OBJECTIVES

This study investigated the relapse pattern and oncologic outcomes after laparoscopic nephroureterectomy with template-based lymph node dissection (LND) in patients with clinically node-negative (cN0) upper urinary tract urothelial carcinoma. The frequency of lymph node metastasis, including micrometastases, was also evaluated.

METHODS AND MATERIALS

A total of 105 patients with cTa-3N0M0 upper urinary tract urothelial carcinoma were analyzed, all of whom underwent regional LND during laparoscopic nephroureterectomy. Of those patients, 96 (91%) underwent complete LND in accordance with an anatomical template-based rule. We collected patient characteristics, pathological data, and follow-up data from medical charts. Micrometastases were assessed by pan-cytokeratin immunohistochemistry. Nonurothelial recurrence-free survival and cancer-specific survival were estimated using the Kaplan-Meier method.

RESULTS

The median number of lymph nodes removed was 12 (range, 1-59). Lymph node metastasis was identified by routine pathological examination in 7 (7/105, 6.7%) patients. Pan-cytokeratin immunohistochemistry revealed micrometastases in 5 additional patients (pNmicro +: 5/105, 4.8%). Nonurothelial disease recurrence was observed in 21 (20%) patients at a median of 10 months (range: 1-33) after surgery. Distant metastasis was dominant (15/105, 14.3%), followed by locoregional recurrence (5/105, 4.8%) and both (1/105, 0.95%). The 5-year nonurothelial recurrence-free survival rates were 84.8% for pN0, 53.3% for pNmicro+, and 19.1% for pN+ (3-sample log-rank test, P < 0.0001). The 5-year cancer-specific survival rates were 95.0% for pN0, 53.3% for pNmicro+, and 23.8% for pN+ (P < 0.0001).

CONCLUSIONS

Our observation showed that template-based LND could contribute to precise disease staging and better local disease control probably by eliminating nodal disease, compared with previous studies. The survival impact and ideal management of pNmicro+ disease should be evaluated in a larger cohort.