May 15, 2024

Coalition Voice

Epithelial Gynecologic Cancers: Three Cancers Under One Umbrella

By Pat Battaglia, Associate Director of Communications

When the International Federation of Gynecology and Obstetrics revised its cancer staging system in 2014 to incorporate epithelial ovarian, fallopian tube, and peritoneal cancer into one umbrella category¹, the group was following the evidence.

The majority of cancers in all three places originate in their surface cells – the epithelial cells. These cells line the outer and inner surfaces of many of our tissues, including the ovaries, fallopian tubes, and peritoneum. Viewed under a pathologist’s microscope, cancers originating in the epithelium of all three sites look the same. Malignancies arising in one of these areas can spread into one or both of the others. In fact, recent evidence has led to the hypothesis that most ovarian cancers may have actually begun in a fallopian tube. Regardless of the site of origin, the clinical behavior of these three cancers – including the way they appear under a microscope, their response to surgery, and sensitivity to chemotherapy – are so similar that epithelial cancers diagnosed in any of these three sites are treated the same way.²

Taken as a group, ovarian, fallopian tube, and primary peritoneal cancers have a significant impact. They represent 2.5% of new female cancer cases in the United States, with more than 22,000 new diagnoses each year.³

Ovarian Cancer

Most tumors detected in the ovaries are benign. Of those found to be cancerous, about 85% to 90% are the epithelial type.⁴ Epithelial ovarian cancer is further divided into different subtypes, the most common of which is serous ovarian cancer. Other, less common diagnoses include mucinous, endometrioid, and clear cell ovarian cancers. The subtype found in any individual can impact their treatment decisions.⁵

Other, non-epithelial forms of ovarian cancer include germ cell tumors, which arise in the ova or eggs; stromal cell tumors, which are rare and develop on hormone-producing tissues within the ovaries; and small cell carcinoma, an extremely rare ovarian cancer of uncertain origin.⁵

Peritoneal Cancer

About ten percent of all ovarian, fallopian tube, and peritoneal cancers are primary peritoneal cancer (PPC), which means the cancer cells first started growing in the peritoneum – the thin layer of tissue that surrounds most of the abdominal organs, including the reproductive organs.⁶ Because the peritoneum is a non-gender-specific structure, men can be diagnosed with PPC, although this is extremely rare.

Secondary peritoneal cancer occurs when cancers that arise in other parts of the body, including the ovaries, metastasize to the peritoneum. Seventy-five percent of ovarian cancers are found to have spread to the peritoneum at the time they are diagnosed.⁷

Fallopian Tube Cancer

While the evidence suggests that many epithelial ovarian and peritoneal cancers originate from a fallopian tube precursor, primary fallopian tube cancer (FTC) is still a rare diagnosis. Given the uncommon nature of the disease, the literature on primary FTC is limited. With the extreme similarities in clinical behavior between primary epithelial fallopian tube, ovarian, and peritoneal carcinomas, the treatment approach is the same: surgical “debulking” (removing as much of the cancer as possible) and chemotherapy.³

Common Symptoms of Gynecologic Cancer

There is no screening or early detection test for those at average risk of most gynecologic cancers. Cervical cancer is the exception to this, as there is an effective screening method – the PAP smear – as well as a preventive vaccine. Those with a strong family history of any gynecologic cancer or an inherited genetic condition such as Lynch syndrome or a BRCA gene mutation are considered to have an elevated risk. They may be eligible for certain blood tests, transvaginal ultrasounds, or prophylactic surgery to monitor their health and potentially reduce their risk.

Ovarian, peritoneal, and fallopian tube cancers often do not produce noticeable symptoms at first. The signs of these cancers are non-specific; they can be (and often are) caused by conditions other than cancer. However, if you notice any of the following symptoms and they persist for longer than two weeks, contact your gynecologist:

Bloating
Pelvic or abdominal pressure or pain
Difficulty eating or feeling full quickly
Urinary symptoms (urgency or frequency)⁵

Although the initial consultations in cases of suspected gynecologic cancer will often include imaging and bloodwork, the only way to definitively diagnose ovarian, peritoneal, or fallopian tube cancer is through a surgical biopsy. When considering surgery for a suspected GYN cancer, it is helpful to consult with a gynecologic oncologist. Research has demonstrated that those whose surgeries are performed by these specialists are most likely to experience the best possible outcomes.⁸

If you are diagnosed with any one of the family of epithelial gynecologic cancers – or with any form of gynecologic or breast cancer – you are not alone. Call us at the Coalition. Our supportive survivor community and educational programming can help as you navigate this uncertain terrain. We are here for you.

This story appeared in the Spring 2024 newsletter, Voices of the Ribbon.

Coalition Voice