Pilot Study of the Lavage of the Uterine Cavity for the Diagnosis of Serous Tubal Intraepithelial Carcinoma

The term "high grade serous carcinoma" (HGSC) describes a group of ovarian, tubal and peritoneal cancers with an aggressive biological behavior. HGSC is the leading cause of death from gynecologic malignancy in western civilized countries. Women affected, usually have advanced stage disease with metastatic spread throughout the abdominal cavity at time of diagnosis. Five-year survival rates are in the range of 10 to 30 percent. The specificity of current diagnostic tools (CA-125 and transvaginal ultrasonography) is low and ineffective at detecting HGSC early enough to improve clinical outcomes. Definitive diagnosis of HGSC mostly relies on surgical confirmation. These findings underline the need for an effective test for early detection of HGSC. In the general population, the lifetime risk is 1.5 percent.

Women with germ line mutations in the BRCA1 and BRCA2 gene or a strong family history of epithelial ovarian cancer carry a high risk for breast cancer and/or HGSC development. Familial or inherited syndromes account for approximately 13 percent of cases of invasive epithelial ovarian and fallopian tube cancer. The lifetime risk of ovarian cancer is 35 to 46 percent in women with BRCA1 gene mutations and 13 to 23 percent in those with BRCA2 mutations. Again, even in this population with high-risk for HGSC, the specificity of CA-125 and transvaginal ultrasonography is still too low and ineffective to improve clinical outcomes.

Over the last years, increasing scientific evidence conglomerated that a large proportion of not only familial HGSC develop primarily in the lining of the fallopian tube, that resembles Müllerian epithelium. These precursor lesions are called "serous tubal intraepithelial carcinomas" (STICs) and are characterized by p53 overexpression on immunohistochemistry and high Ki-67 labelling index indicating a high proliferation index. In over 90 percent, STICs carry mutations in the TP53 tumor suppressor gene.

As for today, risk reducing bilateral salpingo-oophorectomy (rrBSO) is the most effective approach to reducing the risk of HGSC in high risk women. Among women with an increased risk of HGSC (most with BRCA mutations) who underwent rrBSO, 4 to 17 percent are found to have a STIC or even invasive neoplasm, and approximately 80 percent of these neoplasms are in the ampullar part of the fallopian tube.

Recent findings highlighted the malignant potential of STICs. On histopathological specimen, intraluminal shedding of tumor cells from STICs can be frequently demonstrated in the fallopian tube. This shedding of tumor cells from STICs appears to be a risk factor for early transperitoneal metastasis frequently found in HGSC. There is a strong clinical need for screening for STICs, since they are the precursor lesion of HGSC. These facts underline the importance of an effective - non-invasive - test for early detection of STICs.