Pelvic lymph node dissection in early ovarian cancer: success of retrieval of lymph nodes by individual lymph node groups in respect to pelvic laterality

Objective

To evaluate the differences in number of harvested retroperitoneal pelvic lymph nodes by specific lymph node regions in respect to pelvic laterality.

Study design

We extracted cases of early ovarian cancer (EOC) with lymphadenectomy from the medical database which were treated at our institution in the period between 1994 and 2008. Recommendations of FIGO and EGSOC (European Guidelines for Staging in Ovarian Cancer) for staging of ovarian malignancies were followed. Stage of the disease was established on the basis of intra-abdominal condition which we found during surgery and histopathologic status of retroperitoneal lymph nodes (LN). For each case and every LN group, we subtracted the number of dissected lymph nodes on the left side from the number of dissected lymph nodes on the right side of the pelvis. The result would represent the difference between number of removed LN on each side of the pelvis for specific LN group. A negative difference means that a greater number of LN was extracted from the left side and a positive difference that the greater number of LN was extracted from the right side of the pelvis. We used Wilcoxon signed-rank test for statistical analysis of differences.

Results

48 cases with EOC underwent lymphadenectomy. In three cases, metastatic retroperitoneal pelvic lymph nodes were found. There were 79.1%, 50.0%, 45.8%, 93.8%, 52.1%, 60.4% and 70.8% of cases with left-right difference in number of removed lymph nodes in external iliac region, common iliac region, presacralic, above obturator nerve, under obturator nerve, lateral from the external ilac vessels and lateral from the common iliac vessels nodal group, respectively. The mean differences between left and right groups were in the range from 2 to 4 lymph nodes. There was no identifiable bias toward either side of the pelvis for any of the analyzed lymph node groups.

Conclusion

There is a right and left prevalence of retrieved LN by individual LN regions in the pelvis that could be influenced by asymmetry in right-left pelvic LN distribution. However, we did not find any evidence that the observed imbalance is, on average, directed toward either side of the pelvis.