Objective The evolving knowledge of ovarian carcinogenesis sets the stage for our understanding of high-grade serous pelvic carcinoma (HGSC). Findings in prophylactic surgery introduced serous tubal intraepithelial carcinoma (STIC) as potential precursor of HGSC. The present study explores whether STIC instead should already be considered as an early stage of HGSC with a need for comprehensive staging and therapy.

Patients and Methods We identified all consecutive patients with HGSC who received first-line therapy in our referral center for gynecologic oncology from January 2011 to April 2016. All chemo-naive patients with upfront debulking surgery in whom an association of STIC and tumor lesions could be analyzed were included. Patients with previous removal of the adnexa or overgrown of the fallopian tube by the tumor were excluded. Pathological workup of the fallopian tubes according to the SEE-FIM protocol was conducted.

Results We analyzed a series of 231 consecutive patients with HGSC of whom 121 (52.4%) had ovarian cancer, 74 (32.0%) had cancer of the fallopian tubes and 36 patients (15.6%) had primary peritoneal cancer. Serous tubal intraepithelial carcinoma could be identified in 158 (68.4%) of 231 patients; of 22 patients, 28.1% is ovarian cancer, 30.8% cancer of the fallopian tubes, and 9.5% peritoneal cancer. Four patients without any further intra-abdominal disease were identified of whom 2 patients had stage FIGO IA and 2 patients had lymph node metastases only.

Conclusions Our data suggest that STIC should be regarded as a malignant lesion with metastatic potential. Therefore, we recommend a comprehensive surgical staging including lymphadenectomy.