Borderline Ovarian Cancer: Understanding Diagnosis and Treatment

Borderline ovarian cancer, sometimes referred to as borderline ovarian tumors (BOT) or ovarian tumors of low malignant potential (LMP), is a unique form of ovarian cancer that falls between benign and malignant tumors.

Recent research continues to refine our understanding of these complex tumors, particularly their relationship to low-grade serous ovarian cancer and optimal treatment approaches for younger patients.

In this article, we’ll explore the nuances of borderline ovarian cancer (also commonly called borderline ovarian tumor, or BOT), from its diagnosis and treatment to the emotional aspects of coping with this less common but significant condition.

Understanding Borderline Ovarian Cancer

Borderline ovarian cancer occupies a unique position between benign and malignant tumors. Histologically, it’s characterized by atypical epithelium that doesn’t invade the stroma, or supportive tissue, of the ovary. 

This key feature distinguishes it from more aggressive forms of ovarian cancer. Typically affecting younger women, the median age at diagnosis ranges from 40 to 50 years — significantly younger than the 62.6-year average for high-grade ovarian cancers.

Borderline ovarian cancer is relatively rare, with an estimated incidence of about 4.8 women per 100,000 annually in the United States. But here’s what’s crucial: despite being “borderline,” these tumors still require expert care and long-term monitoring.

Are Borderline Ovarian Tumors Considered Cancer?

This question keeps many patients awake at night, and honestly? The answer isn’t black and white.

The classification of borderline ovarian tumors as cancer remains a subject of ongoing debate in the medical community. While these tumors exhibit some features of malignancy, such as abnormal cell growth, they lack the invasive properties of typical ovarian cancer.

The World Health Organization (WHO) classifies borderline ovarian tumors as a distinct category, separate from benign and malignant ovarian neoplasms. However, due to their potential for recurrence and the need for long-term monitoring, many experts consider borderline ovarian tumors to be a form of low-grade cancer.

The bottom line? Whether or not they’re technically “cancer,” they’re serious enough to require specialized treatment and ongoing surveillance.

Types of Borderline Ovarian Tumors

Borderline ovarian tumors can be classified into two main types based on their histological characteristics: serous and mucinous.

Serous borderline ovarian tumors (SBOTs): SBOTs are the most common type of BOTs, accounting for approximately 65% of all cases. They are characterized by the presence of complex papillary structures lined by stratified epithelium with mild to moderate atypia. 

Here’s where it gets interesting: SBOTs are often found alongside low-grade serous ovarian carcinoma (LGSOC) in pathology reports. Some doctors hypothesize that SBOTs may have the potential to develop into LGSOCs over time, although this relationship isn’t yet definitively established. (Read more: LGSOC vs BOT: Understanding Two Distinct Ovarian Tumors)

Practical tips for patients with SBOTs:

• Discuss the potential risk of developing LGSOCs with your healthcare team and understand the importance of long-term follow-up
• Attend all scheduled check-ups and inform your doctor about any new symptoms or concerns
• Consider seeking a second opinion from a gynecologic oncologist who specializes in ovarian tumors

Mucinous borderline ovarian tumors (MBOTs): MBOTs are less common than SBOTs, representing approximately 35% of all BOTs. They are characterized by the presence of glands or cysts lined by atypical mucinous epithelium, often with a complex branching architecture. 

Unlike SBOTs, MBOTs are generally not associated with the development of invasive carcinomas. However, they can occasionally show areas of microinvasion, which requires careful evaluation and monitoring.

For patients with MBOTs:

• While MBOTs have a lower risk of developing into invasive carcinomas, regular follow-up remains essential
• Discuss the appropriate frequency of check-ups and necessary tests with your doctor
• Be aware of any changes in your symptoms and report them promptly

Understanding your specific type of borderline ovarian tumor is crucial for guiding discussions about prognosis, treatment options, and long-term management.

(Read more about the different types of borderline ovarian tumors.)

Borderline Ovarian Cancer: Diagnosis and Staging

Diagnosing borderline ovarian cancer involves a series of tests similar to those used for other ovarian cancers, but the interpretation requires specialized expertise.

Diagnostic Tests

Imaging tests: Ultrasounds, CT scans, and MRIs help visualize the ovarian tumor and assess its size and extent. But here’s the frustrating reality — there’s currently no definitive way to confirm diagnosis without surgical biopsy.

At Not These Ovaries, we’re actively funding research to identify better ways to diagnose ovarian cancer earlier and more accurately.

Surgical biopsy: A gynecologic oncologist surgeon will typically obtain a tissue sample during surgery for an initial pathology, but it can take up to two weeks for a complete pathology report. The biopsy results will confirm the diagnosis and provide crucial information about the tumor’s characteristics.

Staging System

Borderline ovarian tumors are staged using the FIGO staging system, which ranges from Stage I to Stage IV. However, unlike invasive ovarian cancers, BOTs are less likely to spread beyond the ovaries and are generally associated with a more favorable prognosis.

• Stage I: The tumor is confined to one or both ovaries (approximately 80% of BOT cases)
• Stage II: The tumor involves one or both ovaries with pelvic extension
• Stage III: The tumor involves peritoneal metastasis outside the pelvis and/or regional lymph node metastasis
• Stage IV: Distant metastasis beyond the peritoneal cavity (rare for BOTs)

It’s important to note that while the staging system is the same, the prognosis and treatment options for BOTs differ significantly from those of invasive ovarian cancers.

Creating a Treatment Plan for Borderline Ovarian Cancer

The treatment approach for borderline ovarian cancer typically differs dramatically from that of malignant ovarian cancer due to its less aggressive nature. Here’s what you need to know:

Surgery: The Gold Standard

Surgery is the primary — and often only — treatment needed. The goal? Remove as much of the tumor as possible while preserving fertility when feasible.

Why a gynecologic oncologist matters: Choosing to see a gynecologic oncologist for your surgery can make a world of difference. Research consistently shows that surgery success rates nearly double when performed by these specialists compared to general surgeons.

Surgical Options

Conservative surgery: For younger patients wanting to preserve fertility, surgeons may be able to remove just the affected ovary and some lymph nodes if it’s safe to do so. This approach is often possible in early-stage disease.

Debulking surgery: In more advanced cases, debulking surgery might be necessary. This procedure aims to remove as much of the cancer as safely as possible. Depending on how far the cancer has spread, it might involve removing parts of other organs, lymph nodes, or the omentum.

Oophorectomy: Sometimes, removing one or both ovaries may be recommended. This is more likely if the disease is advanced or if you’ve completed childbearing.

What About Chemotherapy?

Here’s where borderline ovarian cancer differs significantly from other types: Chemotherapy is NOT recommended for borderline ovarian cancer. Surgery and ongoing surveillance are the current standard of care.

This can be confusing for patients who expect “cancer” to require chemotherapy, but borderline tumors simply don’t respond to standard chemotherapy for ovarian cancer protocols the way malignant tumors do.

The Critical Importance of Second Opinions

With the rarity of a borderline ovarian cancer diagnosis, we strongly recommend you get a second opinion from another specialized physician. Why? Because it’s unfortunately commonly misdiagnosed as low-grade serous ovarian carcinoma (LGSOC). This distinction matters enormously for your treatment plan and prognosis.

The Emotional Rollercoaster

A borderline ovarian cancer diagnosis can evoke a complex mix of emotions that many don’t expect:

• Fear and uncertainty: The uncertainty of the disease and its potential impact on fertility can be emotionally challenging. Many patients struggle with questions like: “Is this really cancer?” “Will it come back?” “Can I still have children?”
• The fertility factor: For younger women, the impact on fertility often becomes a central concern. If you’re facing fertility-sparing surgery, working with both a gynecologic oncologist and a fertility specialist is crucial.
• Menopause challenges: A hysterectomy in younger women will cause surgery-induced menopause quickly. Most gynecologic oncologists don’t recommend hormone replacement therapy, which will have material impacts on your health and quality of life. Learning essential menopause nutrition tips will help nourish your body and alleviate symptoms.
• Coping strategies: Seeking support from loved ones, mental health professionals, or ovarian cancer support groups can provide valuable assistance in navigating these emotions.

Support Systems and Resources

Building a strong support network and accessing resources can help individuals and their loved ones cope with borderline ovarian cancer:

• Medical team: Engage with a healthcare team that specializes in ovarian cancer to ensure you receive the most appropriate care.
• Fertility preservation: If fertility preservation is a concern, consult with a fertility specialist to explore options before treatment.
• Support groups: Connect with others who have experienced borderline ovarian cancer to share experiences and gain insight.

Borderline ovarian cancer may be less aggressive than other forms of ovarian cancer, but it still presents unique challenges and uncertainties. By understanding the diagnosis process, exploring treatment options tailored to individual needs, addressing emotional well-being, and accessing support systems, individuals and their loved ones can navigate this journey with resilience.

Not These Ovaries is committed to providing support, information, and hope for those affected by borderline ovarian cancer. Our ovarian cancer research fund aims to improve outcomes and develop better treatments, and your support enables us to continue this vital work. Together, we can make a difference in the lives of those impacted by ovarian cancer.