First Analysis of the Incidence of Serous Tubal Intraepithelial Carcinoma (STIC) in Germany – Evaluation of the Cancer Registry of the Federal State of Rhineland-Palatinate from 2016 to 2023

Introduction: Serous tubal intraepithelial carcinomas (STIC) are classified as precursor lesions of high-grade serous carcinomas (HGSC) in women. STIC are rare and their incidence, prognosis and therapy remain unclear. Since 2021, all cases of isolated STIC in Germany must be reported, which means that all STICs in the German federal state of the Rhineland-Palatine (RLP) are available for evaluation. Material and Methods: A systematic search of the pathology reports in the RLP cancer registry was carried out for the period 01/2016-12/2023 using keywords related to STIC, and the results of the search were evaluated. Results: 382 pathology reports were identified as relevant and screened. A total of seven patients with isolated STIC were reported to the RLP registry in the years 2020-2022. This corresponds to 0.014% of all reported cases of cancer in women in RLP in this period. Six patients had a diagnosis of isolated STIC, identified during risk-reducing salpingo-oophorectomy (RRSO). The mean patient age at the time of RRSO was 60.29 (± 7.09) years. RRSO was carried out on average 9.38 (± 6.75) years after a primary diagnosis of breast cancer/DCIS in five patients. No HGSC was reported for any of the patients with isolated STIC in the follow-up period until 01/2024. 43 synchronous STICs were reported for the period from 01/2016 to 12/2023. Conclusion: 2-3 diagnoses of isolated STIC were recorded annually in RLP in the years 2020-2022. To date, there have been no reports of HGSC in these patients. In the future, the systematic recording of STICs will be expanded to include the cancer registries of other federal states of Germany and it will be possible to obtain valid data on the incidence of STIC in Germany. The collected data will also provide the basic information for a national STIC registry.