6. Management of Serous Tubal Intraepithelial Carcinoma (STIC)

​More extensive examination of the fallopian tubes and increased uptake of risk reducing procedures (BRCA1/2 mutation carriers) or opportunistic salpingectomies (general population) have resulted in the increased detection of serous tubal intraepithelial carcinoma (STIC) in the fallopian tubes, the putative precursor lesion to high-grade serous carcinomas of the ovary.

When performing a risk reducing bilateral BSO for women with a BRCA1 or BRCA2 mutation, a STIC will be found in approximately 3.5-5.5% of patients [48-49]. In women having an opportunistic salpingectomy for benign disease or in women with a high-risk family history, STIC may be found in approximately 0.6-1.1% of patients.

When an isolated STIC is identified during risk-reducing BSO for BRCA1 or BRCA2, a referral should be made to BC Cancer for consideration of completion surgical staging (minimum washings, omentectomy, directed biopsies, +/- hysterectomy). Approximately 10% of high-risk women (with BRCA1 or BRCA2 mutations) with a STIC will have a concurrent HGSC of the ovary following surgical staging [51]. In addition, these patients are at risk of developing primary peritoneal carcinoma, the median time to the development being 4-6 years. The 5-year risk is 10.5%, and the 10-year risk is 27.5% [52]. However, based on currently knowledge, only those with invasive disease found at the time of completion surgery should be offered post-operative chemotherapy.

When an isolated STIC is identified in a patient at 'low risk'/general population, a referral should be made to both BC Cancer Surgical Gynecologic Oncology for consideration of completion surgical staging as well as to the BC Cancer Hereditary Cancer Program. These women have an elevated risk (~30%) of carrying a germline BRCA1 or BRCA2 mutation. These patients also are at risk of developing subsequent primary peritoneal carcinoma [53].

References

48. Chay, W.Y., et al., Outcomes of Incidental Fallopian Tube High-Grade Serous Carcinoma and Serous Tubal Intraepithelial Carcinoma in Women at Low Risk of Hereditary Breast and Ovarian Cancer. Int. J. Gynecol. Cancer, 2016. 26(3): p. 431-6.

49. Long Roche, K.C., et al., Risk-reducing salpingectomy: Let us be opportunistic. Cancer, 2017. 123(10): p. 1714-1720.

50. Patrono, M.G., et al., Clinical outcomes in patients with isolated serous tubal intraepithelial carcinoma (STIC): A comprehensive review. Gynecol. Oncol., 2015. 139(3): p. 568-72.

51. Ruel-Laliberté J., Kasasni S.M., Oprea D., Viau M. Outcome and Management of Serous Tubal Intraepithelial Carcinoma Following Opportunistic Salpingectomy: Systematic Review and Meta-Analysis. J. Obstet. Gynaecol. Can. 2022 Nov;44(11):1174-1180. doi: 10.1016/j.jogc.2022.08.018. Epub 2022 Sep 12. PMID: 36099965.

52. Steenbeek M.P., van Bommel M.H.D., Bulten J., Bogaerts J., Garcia C., Cun H.T., Lu K.H., van Beekhuizen H.J., Minig L., Gaarenstroom K.N., Nobbenhuis M., Krajc M., Rudaitis V., Norquist B.M., Swisher E.M., Mourits M.J.E., Massuger L.F.A.G., Hoogerbrugge N., Hermens R.P.M.G., IntHout J., de Hullu J.A.  Risk of Peritoneal Carcinomatosis After Risk-reducing Salpingo-oophorectomy: A systematic review and individual patient data meta-analysis. J. Clin. Oncol. 2022;40(17). https://doi.org/10.1200/JCO.21.02016

53. Stewart K.T., Hoang L., Kwon J.S. Serous tubal intraepithelial carcinoma (STIC) outcomes in an average risk population. Gynecol. Oncol. Rep. 2024 Feb 8;51:101334. doi: 10.1016/j.gore.2024.101334. PMID: 38370398; PMCID: PMC10869241.