The primary goal of this prospective study is to define the efficacy of the sentinel lymph node biopsy (SLNB) procedure by comparing it to the results obtained from systematic lymphadenectomy, each performed in participants with a suspicious adnexal mass for early-stage ovarian cancer.

Ovarian cancer is the leading cause of mortality among gynecologic cancers. Although most women are diagnosed at advanced stage, about 20% are can be diagnosed at an earlier stage. Treatment and prognosis depends on the correct assessment of stage of the apparently early stage (Stage I and II). About 10-30% of apparently early stage ovarian cancer patients are upstaged based on the final pathology report. Detection of positive lymph node is an important contributor for upstaging of apparently early stage ovarian cancer. However, systematic lymphadenectomy carries immediate and long term risks for patients including bleeding, massive transfusions, prolongation of operation time, serious major vessel and major abdominal organ injury and death. These risks are especially increased in paraaortic lymphadenectomy which is an integral part of staging procedure in early ovarian cancer.

Sentinel lymph node biopsy (SLNB) procedure is the biopsy of one or two lymph node(s) which represents the lymph node basin draining the area of malignancy. This biopsy may potentially eliminate the need systemic pelvic / paraaortic lymphadenectomy. Although SLNB became an integral and accepted procedure in endometrium and cervix cancers, available data on the SLNB for ovarian cancer is limited and is in its infancy to be incorporated in routine practice of ovarian cancer surgery.

So, investigators aim to compare the effectiveness of SLNB procedure results with systematic lymphadenectomy, both performed in each participant, either by laparotomy or laparoscopy.

Technically, 2-4 mL of sterile black carbon stain is carefully injected beneath the adnexal mass just under peritoneal covering of mesovarium or infundibulopelvic ligament avoiding intravascular injection before removal of suspicious adnexal mass for frozen section. This is done classically through a laparotomy incision but can also be performed laparoscopically via a needle introduced transcutaneously into the base of adnexa under optical supervision. 10-15 minute interval is allowed before resection of adnexal mass for frozen section. A peritoneal incision and pelvic and paraaortic retroperitoneal dissection is carried out for identification of major vessels and important surgical landmarks (abdominal ureters, gonadal vessels, inferior mesenteric artery and etc.) up to the left renal vein to visually detect the sentinel lymph node(s) stained in black. Lymphatic vessels are carefully eliminated visually not to be biopsied instead of sentinel lymph node. An additional 2 mL injection is allowed if a SLN could not be detected before systematic lymphadenectomy, adnexectomy and other surgical staging procedures. Frozen section of a adnexal mass is carried out thereafter following the detection and biopsy of SLN. Systematic lymphadenectomy is abandoned in case of a non-malignant frozen section result.

Inclusion Criteria:

Must have a suspicious adnexal mass for early stage ovarian cancer

Must be medically and surgically fit enough to perform SLNB and complete the systematic lymphadenectomy.

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Exclusion Criteria:

Ovarian mass with low probability for early stage ovarian cancer.

Medical or surgical contraindications for surgical comprehensive staging.

Metastatic cancers or double primary cancers (metachronous) of ovary

Recurrent ovarian cancer

Preoperative or intraoperative finding of advanced ovarian cancer (FİGO stage III and IV)

Neoadjuvant ovarian cancer

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No party in our clinical trial are prevented from having knowledge of the interventions assigned to individual participants.