Serous Tubal Intraepithelial Carcinoma - Causes, Symptoms, and Treatment

What Is Serous Tubal Intraepithelial Carcinoma (STIC)?

The serous tubal intraepithelial carcinoma (STIC) is the precursor lesion of the following:

1. High-grade serous pelvis carcinomas.

2. Carcinosarcoma.

3. Undifferentiated carcinoma.

It has an incidence of 0.6 percent to seven percent in BRCA carriers or women with a strong family history of breast or ovarian carcinoma. Serous tubal intraepithelial carcinoma (STIC) is a pathomorphological lesion with uncertain biological and clinical implications.

What Are the Other Names for Serous Tubal Intraepithelial Carcinoma?

Serous tubal intraepithelial carcinoma is also known as:

1. TIC (tubal intraepithelial carcinoma).

2. STIN (serous tubal intraepithelial neoplasia).

What Are Pelvic Serous High-Grade Carcinomas (HGSCs)?

Pelvic serous high-grade carcinomas (HGSCs) comprise carcinomas of:

1. Ovaries.

2. Fallopian tubes.

3. Peritoneum.

What Are the Precursor Lesions of High-Grade Serous Carcinoma (HGSC)?

Molecular studies are required to confirm the involvement of serous tubal intraepithelial carcinoma as a precursor lesion. Identifying molecules up-regulate in serous tubal intraepithelial carcinoma is essential for identifying biomarkers to aid in STIC diagnosis.

It also helps to understand high-grade serous carcinoma(HGSC) pathophysiology. The precursor lesions of high-grade serous carcinoma (HGSC) of the fallopian tube are as follows:

1. P53 signature.

2. Secretory cell outgrowths (SCOUTs).

3. Serous intraepithelial lesion of the fallopian tube (STIL).

4. Serous intraepithelial carcinoma of the fallopian tube (STIC).

5. Serous tubal intraepithelial carcinoma (STIC).

How Are Serous Tubal Intraepithelial Carcinoma Classified?

Pelvic high-grade serous carcinoma (HGSC) is a type II tumor that is composed primarily of:

1. Carcinosarcoma.

2. Undifferentiated carcinoma.

3. High-grade serous carcinomas.

It can be further split into morphological and molecular subtypes. Many type II carcinomas originate from serous tubal intraepithelial carcinoma. As a result, serous tubal intraepithelial carcinoma is the most common subtype of pelvic high-grade serous carcinoma (HGSC).

How Does Serous Tubal Intraepithelial Carcinoma (STIC) Occur?

The specific cause of serous tubal intraepithelial carcinoma (STIC) is unknown. However, in 1969 researchers reported that it might be caused due to multifocal origin in the fallopian tube. One of the risk factors is excessive gonadotropin secretion. Women with the inherited BRCA (breast cancer gene) mutation have a higher incidence of occult fallopian tube cancer. Immunohistochemical staining, particularly p53 and Ki67 assays, evaluates the fallopian tubes and identifiesseroustubal intraepithelial carcinoma (STIC).

Where Is Serous Tubal Intraepithelial Carcinoma Located?

Serous tubal intraepithelial carcinoma is a significant subset of pelvic high-grade serous carcinomas (HGSCs). It originates particularly in the distal section of the fallopian tube. Serous tubal intraepithelial carcinoma can also be found in the non-fimbriated portion of the fallopian tube.

How Is Serous Tubal Intraepithelial Carcinoma (STIC) Diagnosed?

Patients who develop serous tubal intraepithelial carcinoma (STIC) should be screened for BRCA 1 or 2 mutations. The doctor should evaluate the other parts of the uterus if the initial hematoxylin and eosin (H&E) sections are negative in cases of serous ovarian carcinoma treated with neoadjuvant chemotherapy.

• Confocal and Flexible Microlaparoscopy- Confocal and flexible micro laparoscopy can identify macroscopically abnormal fallopian tube alterations. This procedure shows live views of the fallopian tube lumen. Thus it serves as a guide for biopsies. This device can image organs without substantial difficulties.

• Serous Tubal Intraepithelial Carcinoma (STIC) Fallopian Tube Sampling- Accurate serous tubal intraepithelial carcinoma detection is crucial as a therapeutic and preventive procedure, especially for people with pre-existing gynecologic cancers. A thorough examination of the fallopian tubes is essential for identifying any serous tubal intraepithelial carcinoma.

The embedded fimbria of the fallopian tubes can help detect most of the serous tubal intraepithelial carcinomas. Thus, sectioning the fimbriated end increases the amount of fallopian tube mucosa accessible for microscopic investigation. Check-ups every six months should include gynecological examinations, CA 125 and HE4 testing, and pelvic ultrasound examination.

How Is Serous Tubal Intraepithelial Carcinoma (STIC) Fallopian Tube Sampling Done?

The ampullary part is sectioned at two to three millimeters intervals to maximize exposure of the fimbrial mucosa. The infundibulum is also severed and sectioned longitudinally.

This procedure highlights the relevance of fimbria sampling if there is a link between the tube and ovarian carcinogenesis; the tube section closest to the ovarian surface warrants special attention.

What Is the Importance of Fallopian Tube Sampling?

The fimbria is the part closest to the ovarian surface. It is an epithelial-to-mesothelial transition zone that may differ in biology due to its proximity to the abdominal cavity. The fimbria has a more extensive surface area than the proximal tube, and longitudinal sectioning of the infundibulum and fimbria allows for complete exposure of this area. Fallopian tube sampling has been 75 % successful in detecting fimbrial or tubal lesions after further resectioning the samples.

What Is the Treatment of Serous Tubal Intraepithelial Carcinoma(STIC)?

The increased detection of serous tubal intraepithelial carcinoma (STIC) in the fallopian tubes has resulted in an extensive examination of the fallopian tubes. Approximately 4.5 % of high-risk women with serous tubal intraepithelial carcinoma (STIC) and BRCA1 or BRCA2 mutations would develop primary peritoneal cancer.

Only women with invasive cancer discovered during surgery should be administered postoperative chemotherapy. The surgical procedures are as follows:

• Salpingectomy - In a salpingectomy, one or both fallopian tubes are surgically removed. Serous tubal intraepithelial carcinoma (STIC) is found in women undergoing opportunistic salpingectomy for mild illness or with a high-risk family history.

• Bilateral Salpingo-Oophorectomy (BSO) - It is a surgical operation involving removing the ovaries and fallopian tubes. A serous tubal intraepithelial carcinoma (STIC) will be discovered in around 3.5 to 5.5 % of people after bilateral salpingo-oophorectomy.

What Is the Prognosis of Serous Tubal Intraepithelial Carcinoma (STIC)?

Most patients (75%) are identified in the late stages of the disease (III-IV), with a five-year survival rate of five to 25 %. In the early stages, serous tubal intraepithelial carcinoma (STIC) has a five-year survival rate of 60 to 85%.

Female patients with genetic mutations in the BRCA1 or BRCA2 gene have a better prognosis than patients with sporadic malignancies.

Conclusion

Serous tubal intraepithelial carcinoma (STIC) can be diagnosed by histopathology and immunohistochemistry. The other lesions of pelvic serous high-grade carcinomas (HGSCs) should also be considered during diagnosis. A thorough BRCA1 or BRCA2 mutation screening is mandatory if serous tubal intraepithelial carcinoma has been detected and treatment of such lesions should be given utmost priority.