Sentinel Node Biopsy Feasible to Determine Spread of Early-stage OC

A sentinel node biopsy, used to determine whether cancer has spread to lymph nodes, is a feasible way to obtain information and avoid lymph node dissection in patients with early-stage ovarian cancer, a new study shows.

The study, “Sentinel-Node Biopsy in Early Stage Ovarian Cancer: Preliminary Results of a Prospective Multicentre Study (SELLY),” was published in thea American Journal of Obstetrics and Gynecology.

Epithelial ovarian cancer is the most lethal gynecological tumor. The primary factor that determines life expectancy is the stage at which the patient presents and whether the cancer has metastasized to the lymph nodes.

Unfortunately, only 20–25% of patients are diagnosed at an early stage. And even among these patients, an estimated 14–15% of patients have have lymph node metastasis.

Pre-operative imaging is not very effective when it comes to detecting lymph node metastasis. Therefore, it is recommended for surgeons to do a systemic lymphadenectomy (dissection of all lymph nodes in the pelvic and para-aortic regions) as part of the surgical staging for the disease.

This is important, as information about possible lymph node metastasis can help guide physicians when it comes to making decisions regarding additional treatment.

However, the importance of obtaining this information must be balanced against the risks associated with the procedure, which include injuries to major blood vessels, excessive blood loss, and nerve lesions.

Alternatively, surgeons can conduct a sentinel node biopsy, a surgical procedure that can help determine whether cancer has spread beyond a primary tumor and into the lymphatic system.

The sentinel nodes are the first few lymph nodes into which a cancer spreads.

During a sentinel node biopsy, the surgeon will inject a fluorescent dye near the tumor, which will be taken up by lymph nodes that have metastasis. Using a near-infrared detector, the surgeon can figure out where the fluorescent tracer has accumulated and locate the lymph nodes with possible cancer. The surgeons will then remove these lymph nodes.

A sentinel lymph node biopsy is generally conducted at the same time as the surgery to remove the tumor. After the surgery, the nodes are examined under a microscope for the presence of cancer cells.

Thus far, studies that have investigated the effectiveness of sentinel node biopsy in early-stage epithelial ovarian cancer have not had any conclusive results.

Therefore, researchers are conducting the SELLY trial (NCT03563781), a prospective Phase 2 study designed to test whether sentinel lymph node biopsy can accurately predict lymph node metastasis status in women with early epithelial ovarian cancer.

Results of this study include data from the first 31 patients (of the 79 enrolled so far) that were planned for either immediate or delayed comprehensive staging. Delayed staging was defined as staging conducted in a subsequent surgery, but within 30 days after removal of the ovarian tumor.

Among the 31 patients included, sentinel node was identified in 21 patients, a detection rate of 67.7%. The detection rate was significantly higher in women undergoing immediate staging (88.9%) compared to delayed staging (41.7%).

“Our data show that the detection of sentinel node in early epithelial ovarian cancer is low when patients are submitted to delayed-staging surgery,” the researchers stated.

Overall, four patients were positive for metastasis in lymph nodes, and all were part of the 21 patients for whom a sentinel node was detected. This is led to a sensitivity of 100%, false-negative-rate of 0%, and negative-predictive value of 100%.

Thus, “sentinel node procedure is feasible and has the potential to provide reliable and useful information on nodal status and may allow the avoidance of systematic lymphadenectomy in the majority of patients,” researchers concluded.