Outcome and Prognostic Impact of Surgical Staging in Serous Tubal Intraepithelial Carcinoma: A Cohort Study and Systematic Review

Does serous tubal intraepithelial carcinoma (STIC) metastasize? The clonal relationship between STIC and subsequent high-grade serous carcinoma in BRCA1/2 mutation carriers several years after risk-reducing salpingo-oophorectomy

OBJECTIVE

The majority of high-grade serous carcinomas (HGSC) of the ovary, fallopian tube, and peritoneum arise from the precursor lesion called serous tubal intraepithelial carcinoma (STIC). It has been postulated that cells from STICs exfoliate into the peritoneal cavity and give rise to peritoneal HGSC several years later. While co-existent STICs and HGSCs have been reported to share similarities in their mutational profiles, clonal relationship between temporally distant STICs and HGSCs have been infrequently studied and the natural history of STICs remains poorly understood.

METHODS

We performed focused searches in two national databases from the Netherlands and identified a series of BRCA1/2 germline pathogenic variant (GPV) carriers (n = 7) who had STIC, and no detectable invasive carcinoma, at the time of their risk-reducing salpingo-oophorectomy (RRSO), and later developed peritoneal HGSC. The clonal relationship between these STICs and HGSCs was investigated by comparing their genetic mutational profile by performing next-generation targeted sequencing.

RESULTS

Identical pathogenic mutations and loss of heterozygosity of TP53 were identified in the STICs and HGSCs of five of the seven patients (71%), confirming the clonal relationship of the lesions. Median interval for developing HGSC after RRSO was 59 months (range: 24-118 months).

CONCLUSION

Our results indicate that cells from STIC can shed into the peritoneal cavity and give rise to HGSC after long lag periods in BRCA1/2 GPV carriers, and argues in favor of the hypothesis that STIC lesions may metastasize.

Human peritoneal fluid exerts ovulation- and nonovulation-sourced oncogenic activities on transforming fallopian tube epithelial cells

Secretory cells in the fallopian tube fimbria epithelium (FTE) are regarded as the main cells of origin of ovarian high-grade serous carcinoma (HGSC). Ovulation is the main cause of FTE oncogenesis, which proceeds through a sequence of TP53 mutations, chromosomal instability due to Rb/cyclin E aberration, in situ carcinoma (STIC), and metastasis to the ovary and peritoneum (metastatic HGSC). Previously, we have identified multiple oncogenic activities of the ovulatory follicular fluid (FF), which exerts the full spectrum of transforming activity on FTE cells at different stages of transformation. After ovulation, the FF is transfused into the peritoneal fluid (PF), in which the FTE constantly bathes. We wondered whether PF exerts the same spectrum of oncogenic activities as done by FF and whether these activities are derived from FF. By using a panel of FTE cell lines with p53 mutation (FT282-V), p53/CCNE1 aberrations (FT282-CCNE1), and p53/Rb aberrations plus spontaneous transformation, and peritoneal metastasis (FEXT2), we analyzed the changes of different transformation phenotypes after treating with FF and PF collected before or after ovulation. Similar to effects exhibited by FF, we found that, to a lesser extent, PF promoted anchorage-independent growth (AIG), migration, anoikis resistance, and peritoneal attachment in transforming FTE cells. The more transformed cells were typically more affected. Among the transforming activities exhibited by PF treatment, AIG, Matrigel invasion, and peritoneal attachment growth were higher with luteal-phase PF treatment than with the proliferative-phase PF treatment, suggesting an ovulation source. In contrast, changes in anoikis resistance and migration activities were similar in response to treatment with PF collected before and after ovulation, suggesting an ovulation-independent source. The overall transforming activity of luteal-phase PF was verified in an i.p. co-injection xenograft mouse model. Co-injection of Luc-FEXT2 cells with either FF or luteal-phase PF supported early peritoneal implantation, whereas co-injection with follicular-phase PF did not. This study, for the first time, demonstrates that PF from ovulating women can promote different oncogenic phenotypes in FTE cells at different stages of malignant transformation. Most of these activities, other than anoikis resistance and cell migration, are sourced from ovulation.

Clinical significance of risk-reducing salpingo-oophorectomy in patients with BRCA1/2 mutation

OBJECTIVE

Serous tubal intraepithelial carcinoma (STIC) is a precursor lesion which is located in the distal fallopian tube and causes high grade serous ovarian carcinoma (HGSOC). The incidence of STIC for women underwent risk reducing salpingo-oophorectomy for BRCA mutation varies from 0.6 to 7% and its clinical outcomes are still unclear. The aim of this study was to demonstrate the incidence of STIC and HGSOC in BRCA1/2 mutation carriers after risk reducing salpingo-oophorectomy (RRSO) and the clinical outcomes of these patients.

MATERIAL AND METHODS

We retrospectively reviewed the records of 48 BRCA1 and/or 2 mutation carriers who underwent prophylactic salpingo-oophorectomy with or without hysterectomy at the Department of Obstetrics and Gynecology, Bursa Uludag University between January 2000 and January 2022.

INCLUSION CRITERIA

BRCA 1 and/or 2 mutation carriers diagnosed by genetic testing, asymptomatic patients with no abnormal findings on pelvic examination.

EXCLUSION CRITERIA

patients with no abnormal findings on pelvic examination and a presence of a personal history of ovarian, fallopian tube or peritoneal cancer.

RESULTS

A total of 48 BRCA 1 and/or 2 mutation carriers underwent RRSO. STIC was diagnosed in 1 (2,0%) patient and restaging surgery was not performed. Primary peritoneal carcinoma (PPC) did not develop during the 20 months follow-up period. One (2.0%) patient was diagnosed with occult ovarian cancer. Restaging surgery was performed and chemotherapy treatments were given after surgery. A pelvic recurrence developed 25 months after the occult cancer diagnosis in the follow up period. One (2.0%) patient with normal histopathological findings after RRSO was diagnosed with peritoneal cancer 57 months after the operation.

CONCLUSION

The risk of PPC continues after RRSO. Therefore, close follow-up procedure is very important for early diagnosis and effective treatment of patients with PPC after RRSO.

A questionnaire-based survey on the diagnostic and therapeutic approaches for patients with STIC in Germany

PURPOSE

Despite the growing understanding of the carcinogenesis of pelvic high-grade serous carcinoma (HGSC) of the ovary and peritoneum and its precursor lesion serous tubal intraepithelial carcinoma (STIC), evidence-based proven recommendations on the clinical management of patients with STIC are lacking so far.

METHODS

A questionnaire containing 21 questions was developed to explore the clinical experience with patients with the diagnosis of STICs and the diagnostic, surgical and histopathological approaches in Germany. Overall, 540 clinical heads of department in all German gynaecological centres were asked to participate.

RESULTS

131 questionnaires (response rate 24.3%) were included in this survey. 45.8% of the respondents had treated one to three STIC patients during their career. 75.6% of the respondents performed opportunistic bilateral salpingectomies during other gynaecological surgeries. Most of the participants (31.3%) started with the SEE-FIM (Sectioning and Extensively Examining the FIMbria) protocol in 2014. It was requested by 39.7% centres for prophylactic salpingectomies, by 13.7% for both prophylactic and opportunistic salpingectomies and by 22.1% for neither of both. 38.2%, 1.5% and 24.4% of the participants would use the laparoscopic, transverse and midline laparotomic approach for a surgical staging procedure, respectively. 25.6% (54.7%) of the respondents recommended a hysterectomy in premenopausal (versus postmenopausal) patients with a STIC, 24.4% (88.4%) a bilateral oophorectomy and 50.0% (4.7%) an affected side oophorectomy (all p values < 0.001). Omentectomy, pelvic and para-aortic lymphadenectomy would be performed by 60.5% (64.0%), 9.3% (11.6%) and 9.3% (11.6%) of respondents in premenopausal (versus postmenopausal) patients (all p values > 0.05).

CONCLUSION

Our survey highlights significant inconsistency in the management of patients with STIC. Prospective data are urgently needed to elucidate the clinical impact of a STIC lesion and its clinical management.

Ovarian cancer prevention by opportunistic salpingectomy is a new de facto standard in Germany

PURPOSE

The most prevalent and aggressive subtype of epithelial ovarian carcinoma (EOC), high-grade serous carcinoma (HGSC), originates in many cases from the fallopian tubes. Because of poor prognosis and lack of effective screening for early detection, opportunistic salpingectomy (OS) for prevention of EOC is being implemented into clinical routine in several countries worldwide. Taking the opportunity of a gynecological surgery in women at average cancer risk, extramural fallopian tubes are completely resected preserving the ovaries with their infundibulopelvic blood supply. Until recently, only 13 of the 130 national partner societies of the International Federation of Obstetrics and Gynecology (FIGO) have published a statement on OS. This study aimed to analyze the acceptance of OS in Germany.

METHODS

(1) Survey of German gynecologists in 2015 and 2022 by the Department of Gynecology of the Jena University Hospital in co-operation with the Department of Gynecology at Charité-University Medicine Berlin with support of NOGGO e. V. and AGO e. V. (2) Salpingectomy numbers in Germany for years 2005-2020 as retrieved from the Federal Statistical Office of Germany (Destatis).

RESULTS

(1) Survey: Number of participants was 203 in 2015 and 166 in 2022, respectively. Nearly all respondents (2015: 92%, 2022: 98%) have already performed bilateral salpingectomy without oophorectomy in combination with benign hysterectomy with the intention to reduce the risk for malignant (2015: 96%, 2022: 97%) and benign (2015: 47%, 2022: 38%) disorders. Compared to 2015 (56.6%), considerably more survey participants performed OS in > 50% or in all cases in 2022 (89.0%). Recommendation of OS for all women with completed family planning at benign pelvic surgery was approved by 68% in 2015 and 74% in 2022. (2) Case number analysis: In 2020, four times more cases of salpingectomy were reported by German public hospitals compared to 2005 (n = 50,398 vs. n = 12,286). Of all inpatient hysterectomies in German hospitals in 2020, 45% were combined with salpingectomy, and more than 65% in women at the age of 35 to 49 years.

CONCLUSION

Mounting scientific plausibility regarding involvement of fallopian tubes in the pathogenesis of EOC led to change of clinical acceptance of OS in many countries including in Germany. Case number data and widespread expert judgment demonstrate that OS has become a routine procedure in Germany and a de facto standard for primary prevention of EOC.

Risk-reducing salpingo-oophorectomy among Chinese women at increased risk of breast and ovarian cancer

BACKGROUND

Risk-reducing salpingo-oophorectomy (RRSO) is recommended for women at increased risk of breast and ovarian cancer. We launched a prospective study of women receiving RRSO, including those with mutations in genes beyond BRCA1/2.

PATIENTS AND METHODS

80 women were enrolled for RRSO with sectioning and extensively examining the fimbriae (SEE-FIM) protocol between October 2016 and June 2022. The majority of participants had inherited susceptibility gene mutations or a family history suggesting ovarian cancer risk, while patients with isolated metastatic high-grade serous cancer of unknown origin were also included.

RESULTS

Overall, two patients had isolated metastatic high-grade serous cancer with unknown origin, and four patients had family histories but refused to take genetic tests. The rest 74 patients harbored deleterious susceptible gene, including 43 (58.1%) with BRCA1 mutation, and 26 (35.1%) with BRCA2 mutation, respectively. Other mutated genes included ATM (1), BRIP1(1), PALB2(1), MLH1(1) and TP53 (1) in each patient. Among the 74 mutation carriers, three (4.1%) cancers were recognized, one (1.4%) was found to have serous tubal intraepithelial carcinoma (STIC), and five patients (6.8%) was diagnosed with serous tubal intraepithelial lesions (STILs). P53 signature was recognized in 24 patients (32.4%). For other genes, MLH1 mutation carrier had endometrial atypical hyperplasia and p53 signature in fallopian tubes. The germline TP53 mutation carrier had STIC in the surgical specimens. Evidence for precursor escape was also recognized in our cohort.

CONCLUSION

Our study demonstrated clinic-pathological findings of patients at increased risk of breast and ovarian cancer, and expand the clinical application of SEE-FIM protocol.

Risk reducing surgery with peritoneal staging in BRCA1-2 mutation carriers. A prospective study

INTRODUCTION

International guidelines recommend risk-reducing salpingo-oophorectomy (RRSO) in BRCA1-2 mutations carriers to decrease ovarian cancer occurrence. In this prospective study, we describe the incidence of occult malignancies and the surgical outcomes in asymptomatic BRCA mutation carriers submitted to RRSO.

METHODS

Data on BRCA1-2 carriers undergoing RRSO with peritoneal washing and peritoneal/omental biopsies (PeS), between January 2019 until March 2021, were prospectively collected.

RESULTS

A total of 132 patients were enrolled: 74 BRCA1 and 58 BRCA2 mutation carriers. 31.1% women underwent RRSO and PeS (16.2% of BRCA1 and 50% of BRCA2 carriers), while 68.9% patients were submitted also to concomitant hysterectomy. Almost all the procedures (99.2%) were performed by minimally invasive surgery. Postoperative complications occurred in twelve patients (9.1%): 10 in the concomitant hysterectomy group and two complications in the RRSO group. At the final pathological examination, 6 (4.5%) occult carcinomas were diagnosed: 3 fallopian tube carcinomas, one ovarian carcinoma and two serous tubal intraepithelial carcinomas (STICs), with negative PeS. Median age of occult carcinomas patients at RRSO was 54 (range: 48-79) years. The mean follow up was 20 (range: 7-34) months. During the follow up, no primary peritoneal cancer has been diagnosed.

CONCLUSIONS

Occult pathologic findings in RRSO occurred in 4.5% (3% invasive carcinomas, STIC 1.5%) among our patients. The routine use of peritoneal biopsies does not improve the detection of occult malignancies. Our data confirm the importance of timely performing RRSO in BRCA1-2 carriers.

Outcome and Management of Serous Tubal Intraepithelial Carcinoma Following Opportunistic Salpingectomy: Systematic Review and Meta-Analysis

OBJECTIVE

Serous ovarian cancer is the most common subtype of epithelial ovarian carcinoma-the most prevalent type of ovarian cancer. High-grade serous ovarian carcinoma (HGSOC) is thought to arise from the distal fallopian tube, with a precursor lesion known as serous tubal intraepithelial carcinoma (STIC). STICs are found in the final pathology of a salpingectomy specimen in 10%-20% of women with a BRCA gene mutation and 1%-7% of women without a mutation. However, there is currently no official guideline and a paucity of data on the management of STICs.

DATA SOURCES

We performed a systematic review following PRISMA guidelines. Five databases were searched for relevant studies on STICs.

STUDY SELECTION

Two independent reviewers performed the abstract and full-text screening and data extraction, with conflicts resolved through discussion with the third reviewer. The risk of bias of each study was assessed using the Newcastle-Ottawa scale.

DATA EXTRACTION AND SYNTHESIS

Fourteen articles were included. Ninety-nine patients who were diagnosed with STIC and subsequently followed for a mean period of 55.5 months were included in this analysis. Eighty-three patients (83.9%) were BRCA mutation carriers. After the diagnosis of isolated STIC, 7 patients (7.3%) received chemotherapy and 25 (26%) underwent surgical staging. Three of the 25 patients were diagnosed with HGSOC based on the staging surgery. Nine patients were later diagnosed with HGSOC during follow-up, with an average duration of follow-up of 58.5 months between the diagnosis of STIC and the diagnosis of HGSOC.

CONCLUSION

Based on our review of the literature, there is a 10.7% risk of having concurrent HGSOC at the time of STIC diagnosis, and the risk of developing a subsequent HGSOC is 14.5%. BRCA mutation status should be determined in cases of isolated STIC, as 83.9% of patients included in this study were found to carry BRCA mutations. We believe it is necessary to further investigate the role of surgical staging following the diagnosis of STIC.

Incidence of pelvic high-grade serous carcinoma after isolated STIC diagnosis: A systematic review of the literature

Objective

Serous tubal intraepithelial carcinoma (STIC) is a precursor lesion of pelvic high-grade serous carcinoma (HGSC). Information on treatment and outcome of isolated STIC is rare. Therefore, we reviewed systematically the published literature to determine the incidence of subsequent HGSC in the high- and low-risk population and to summarize the current diagnostic and therapeutic options.

Methods

A systematic review of the literature was conducted in MEDLINE-Ovid, Cochrane Library and Web of Science of articles published from February 2006 to July 2021. Patients with an isolated STIC diagnosis and clinical follow-up were included. Study exclusion criteria for review were the presence of synchronous gynaecological cancer and/or concurrent non-gynaecological malignancies.

Results

3031 abstracts were screened. 112 isolated STIC patients out of 21 publications were included in our analysis with a pooled median follow-up of 36 (interquartile range (IQR): 25.3-84) months. 71.4% of the patients had peritoneal washings (negative: 62.5%, positive: 8%, atypic cells: 0.9%). Surgical staging was performed in 28.6% of all STICs and did not show any malignancies. 14 out of 112 (12.5%) patients received adjuvant chemotherapy with Carboplatin and Paclitaxel. Eight (7.1%) patients developed a recurrence 42.5 (IQR: 33-72) months after isolated STIC diagnosis. Cumulative incidence of HGSC after five (ten) years was 10.5% (21.6%). Recurrence occurred only in BRCA1 carriers (seven out of eight patients, one patient with unknown BRCA status).

Conclusion

The rate of HGSC after an isolated STIC diagnosis was 7.1% with a cumulative incidence of 10.5% (21.6%) after five (ten) years. HGSC was only observed in BRCA1 carriers. The role of adjuvant therapy and routine surveillance remains unclear, however, intense surveillance up to ten years is necessary.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021278340.

Serous tubal intraepithelial carcinoma: What Do We Really Know at this Point?

Serous tubal intraepithelial carcinoma (STIC) is the earliest morphologically recognizable step in the development of invasive high-grade serous carcinoma of the fallopian tube. Lesions occurring prior to STIC within the carcinogenic sequence for the pathogenesis of invasive high-grade serous carcinoma include the p53 signature and secretory cell outgrowth (SCOUT). Variable histologic criteria have been used for diagnosing STIC, but a combination of morphology and immunohistochemistry for p53/Ki-67 improves interobserver agreement. Half of all carcinomas identified in risk-reducing salpingo-oophorectomy specimens are in the form of STIC; however, STIC also may be incidentally found on occasion in specimens from women at low or average risk of ovarian/tubal/peritoneal carcinoma. TP53 mutation is the earliest known DNA sequence alteration in STIC and almost all invasive high-grade serous carcinomas of the ovary and peritoneum. Data on the clinical behavior of STIC are limited. While the short-term follow-up in the prior literature suggests a low risk of malignant progression, a more recent meta-analysis indicates a 10-year risk of 28%. STIC probably should be best regarded as a lesion with uncertain malignant potential at present, and future molecular analysis will help classify those with higher risk of dissemination. This review article provides an update on the current knowledge of STIC and related issues.

Risk of Peritoneal Carcinomatosis After Risk-Reducing Salpingo-Oophorectomy: A Systematic Review and Individual Patient Data Meta-Analysis

PURPOSE

After risk-reducing salpingo-oophorectomy (RRSO), BRCA1/2 pathogenic variant (PV) carriers have a residual risk to develop peritoneal carcinomatosis (PC). The etiology of PC is not yet clarified, but may be related to serous tubal intraepithelial carcinoma (STIC), the postulated origin for high-grade serous cancer. In this systematic review and individual patient data meta-analysis, we investigate the risk of PC in women with and without STIC at RRSO.

METHODS

Unpublished data from three centers were supplemented by studies identified in a systematic review of EMBASE, MEDLINE, and the Cochrane library describing women with a BRCA-PV with and without STIC at RRSO until September 2020. Primary outcome was the hazard ratio for the risk of PC between BRCA-PV carriers with and without STIC at RRSO, and the corresponding 5- and 10-year risks. Primary analysis was based on a one-stage Cox proportional-hazards regression with a frailty term for study.

RESULTS

From 17 studies, individual patient data were available for 3,121 women, of whom 115 had a STIC at RRSO. The estimated hazard ratio to develop PC during follow-up in women with STIC was 33.9 (95% CI, 15.6 to 73.9), P < .001) compared with women without STIC. For women with STIC, the five- and ten-year risks to develop PC were 10.5% (95% CI, 6.2 to 17.2) and 27.5% (95% CI, 15.6 to 43.9), respectively, whereas the corresponding risks were 0.3% (95% CI, 0.2 to 0.6) and 0.9% (95% CI, 0.6 to 1.4) for women without STIC at RRSO.

CONCLUSION

BRCA-PV carriers with STIC at RRSO have a strongly increased risk to develop PC which increases over time, although current data are limited by small numbers of events.

Recommendations for diagnosing STIC: a systematic review and meta-analysis

Our understanding of the oncogenesis of high-grade serous cancer of the ovary and its precursor lesions, such as serous tubal intraepithelial carcinoma (STIC), has significantly increased over the last decades. Adequate and reproducible diagnosis of these precursor lesions is important. Diagnosing STIC can have prognostic consequences and is an absolute requirement for safely offering alternative risk reducing strategies, such as risk reducing salpingectomy with delayed oophorectomy. However, diagnosing STIC is a challenging task, possessing only moderate reproducibility. In this review and meta-analysis, we look at how pathologists come to a diagnosis of STIC. We performed a literature search identifying 39 studies on risk reducing salpingo-oophorectomy in women with a known BRCA1/2 PV, collectively reporting on 6833 patients. We found a pooled estimated proportion of STIC of 2.8% (95% CI, 2.0-3.7). We focused on reported grossing protocols, morphological criteria, level of pathologist training, and the use of immunohistochemistry. The most commonly mentioned morphological characteristics of STIC are (1) loss of cell polarity, (2) nuclear pleomorphism, (3) high nuclear to cytoplasmic ratio, (4) mitotic activity, (5) pseudostratification, and (6) prominent nucleoli. The difference in reported incidence of STIC between studies who totally embedded all specimens and those who did not was 3.2% (95% CI, 2.3-4.2) versus 1.7% (95% CI, 0.0-6.2) (p 0.24). We provide an overview of diagnostic features and present a framework for arriving at an adequate diagnosis, consisting of the use of the SEE-FIM grossing protocol, evaluation by a subspecialized gynecopathologist, rational use of immunohistochemical staining, and obtaining a second opinion from a colleague.

Efficacy of risk-reducing salpingo-oophorectomy in BRCA1-2 variants and clinical outcomes of follow-up in patients with isolated serous tubal intraepithelial carcinoma (STIC)

OBJECTIVE

Serous tubal intraepithelial carcinoma (STIC) is currently considered the precursor lesion of pelvic high-grade serous carcinoma. The management of STIC diagnosed after risk-reducing salpingo-oophorectomy (RRSO) in women with BRCA1-2 variants remains unclear. The aim of our study was to evaluate the incidence of STIC, serous tubal intraepithelial lesions (STIL) and occult invasive cancer (OC) and to determine the long-term outcomes of these patients.

METHODS

We conducted a retrospective study of patients with BRCA 1-2 variants who underwent RRSO between January-2010 and Dicember-2020 at the Clinic of Gynaecology of University of Padova.

INCLUSION CRITERIA

women with a negative pelvic examination at the last screening prior to RRSO, patients with fallopian tubes analysed using the SEE-FIM protocol.

EXCLUSION CRITERIA

patients with a positive gynaecologic screening or with ovarian/tubal cancer prior to RRSO.

RESULTS

We included 153 patients. STICs were diagnosed in 4 patients (2.6%) and STILs in 6 patients (3.9%). None of the patients with STIC underwent restaging surgery or adjuvant chemotherapy; all patients were followed closely every 6 months. None of the patients developed primary peritoneal carcinomas (PPCs) with a median FUP of 54.5 months (15-106). OC was diagnosed in 3 patients (2%). All patients with OC underwent staging surgery, and one patient developed a peritoneal carcinoma (PC) after 18 months by staging surgery.

CONCLUSION(S)

The incidence of STIC, STIL and OC after RRSO in BRCA1-2 variants was low. Our results demonstrated that long-term close surveillance in patients diagnosed with STIC should be considered a possible management strategy.

Incidental Serous Tubal Intraepithelial Carcinoma that Developed into Primary Peritoneal Serous Carcinoma in a Patient without BRCA Mutation

Patient: Female, 62-year-old

Final Diagnosis: Peritoneal high grade serous carcinoma

Symptoms: Serous tubal intraepithelial carcinoma

Medication: —

Clinical Procedure: Total laparoscopic hysterectomy and both salpingo-oophorectomy

Specialty: Obstetrics and Gynecology

Pathological findings following risk-reducing salpingo-oophorectomy in BRCA mutation carriers: A systematic review and meta-analysis

OBJECTIVE

To evaluate the benefit of risk-reducing salpingo-oophorectomy (RRSO) by estimating the pathological positive rate of occult lesions, including serous tubal intraepithelial carcinoma (STIC) and occult cancers (OCCs).

METHODS

BRCA1/2 mutation carriers who underwent RRSO in a Chinese study center between 2014 and 2018 were included. A literature review was performed, followed by a meta-analysis of the literature to further validate the findings.

RESULTS

Twenty-four BRCA1/2 mutation carriers who underwent RRSO were identified; one patient (4.2%) had STIC, and one patient (4.2%) had occult fallopian tube cancer complicated by STIC. Thirty-four articles were ultimately included in the meta-analysis. Of the reported cases of OCC, 61.3% occurred in the fallopian tubes and 32.3% in the ovaries, and 81.5% were in the early stages. The estimated rate of overall pathological positive events was 5%. The estimated rates of overall STIC events and OCC were 1% and 3%, respectively. The rates of STIC and OCC were 1% and 3%, respectively, for BRCA1 mutation carriers and 1% and 1%, respectively, for BRCA2 mutation carriers. No significant difference was observed between the results of a routine examination of pathological sections and those of the Sectioning and Extensively Examining the Fimbriae (SEE-FIM) protocol.

CONCLUSIONS

This study is the first report of RRSO results in China. In this systematic review, the positive rates of STIC or OCC after RRSO were no more than 3%, which are 200-fold higher than the risk of the general population. The use of a strict SEE-FIM protocol would likely increase positive results.

Development of Peritoneal Carcinoma in women diagnosed with Serous Tubal Intraepithelial Carcinoma (STIC) following Risk-Reducing Salpingo-Oophorectomy (RRSO)

Introduction

The management of Serous Tubal Intraepithelial Carcinoma (STIC) found at the time of Risk-Reducing Salpingo-Oophorectomy (RRSO) remains unclear. We set out to analyse the incidence of peritoneal carcinomas developed after prophylactic surgery and to formulate further guidance for these patients.

Methods

This is a retrospective study of 300 consecutive RRSO performed at the Royal Marsden Hospital between January 2008 and January 2017.

Results

The median age at RRSO was 47.8 years (range 34 to 60 years) and median BMI was 26.2 kg/m² (range 16 to 51 kg/m²). A total of 273 patients (91%) were tested for BRCA mutations. Of these, 124 (45.4%) had a BRCA 1 mutation, 118 (43.2%) had a BRCA 2 mutation, 2 (0.7%) had both a BRCA 1 and a BRCA 2 mutation and 29 (10.6%) had no BRCA mutation detected. Isolated STIC lesions were identified in 7 cases (2.3%) and p53 signatures in 75 cases (25%). There were five (1.6%) incidental tubal carcinomas and one (0.3%) ovarian carcinoma at the time of surgery. Two (28.6%) of the 7 patients with STIC identified following RRSO had high grade serous peritoneal carcinoma diagnosed at 53 and 75 months. One (0.3%) patient from the other 287 patients from our series with no STIC diagnosis or incidental carcinomas at RRSO developed high grade serous carcinoma of peritoneal origin after 92 months.

Conclusion

This study demonstrates that when a STIC lesion is identified following RRSO there is a significantly higher risk of a subsequent peritoneal cancer. Although there is no published consensus in literature, we recommend that consideration should be given for long term follow-up if a STIC lesion is identified at RRSO.

An Alternate Diagnostic Algorithm for the Diagnosis of Intraepithelial Fallopian Tube Lesions

Intraepithelial fallopian tube neoplasia is thought to be a precursor lesion to high-grade serous carcinoma of the Müllerian adnexae, particularly in women with BRCA1 or BRCA2 mutations. This association has led to recommendations to assess fallopian tubes for intraepithelial atypia. However, the diagnostic reproducibility of a diagnosis of intraepithelial neoplasia is unclear. In this study, 2 gynecologic pathologists independently evaluated sections of fallopian tubes from a sample of women (N=198, 623 slides) undergoing salpingectomy. A total of 101 (54%) women were undergoing risk-reducing salpingo-oophorectomy. Pathologists were blinded to patient histories and prior diagnoses. Pathologists rendered one of three diagnoses for each slide: "negative for fallopian tube intraepithelial neoplasia (FTIN)," "indeterminate for FTIN," or "definite for FTIN." Cases that were considered by histology definite for FTIN or suspicious for FTIN were stained with p53 and Ki67. Pathologists agreed on the diagnosis of "definite for FTIN" 61.5% of the time. There was no agreement on any cases for the diagnosis of "indeterminate for FTIN." Fifteen "indeterminate for FTIN" and 12 "definite for FTIN" cases were stained with p53 and Ki67. Two of the "indeterminate" cases (13%) had p53-positive foci. Five of the "definite" cases had p53-positive foci. In 3 of the other 8 "definite" cases, there was obvious carcinoma present, but the carcinoma did not stain with p53, suggesting a possible null phenotype. We propose that immunostains should only be used to aid in the diagnosis of FTIN in cases with indeterminate histology. The use of p53 immunohistochemistry in cases that were considered "definite for FTIN" by histology was minimally helpful, and in fact often served to further confuse the diagnosis.