Borderline Ovarian Cancer: Understanding Diagnosis and Treatment

June 6, 2024

Borderline Ovarian Cancer: Understanding Diagnosis and Treatment

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

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 shares some similarities with malignant ovarian cancer but differs in several key aspects. It is characterized by abnormal cells that do not invade nearby tissues as aggressively as malignant tumors. This type of cancer often occurs in younger women, with a median age at diagnosis of 40-50 years. Borderline ovarian cancer is considered rare and impacts an estimated ~5 women per 100,000 women per year.

Are Borderline Ovarian Tumors Considered Cancer?

The classification of borderline ovarian tumors as cancer is 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.

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. 

Interestingly, serous borderline tumors are often found alongside low-grade serous ovarian carcinomas (LGSOCs) in pathology reports. Some doctors hypothesize that SBOTs may develop into LGSOCs over time, although this relationship is not yet definitively established. 

Here are some 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 and monitoring.
  • Attend all scheduled check-ups and inform your doctor about new symptoms or concerns.
  • Consider seeking a second opinion from a gynecologic oncologist who specializes in ovarian tumors to ensure you receive the most appropriate care.

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. 

MBOTs are generally not associated with the development of invasive carcinomas, unlike SBOTs. 

  • While MBOTs are less likely to develop into invasive carcinomas, it’s still essential to follow up with your healthcare team regularly to monitor your condition.
  • Discuss the appropriate frequency of check-ups and any necessary tests with your doctor.
  • Be aware of any changes in your symptoms and report them to your healthcare provider promptly.

Patients need to understand the type of borderline ovarian tumor they have been diagnosed with, as this information can help guide discussions with their healthcare team about prognosis, treatment options, and long-term management. Don’t hesitate to ask questions and express your concerns to your healthcare team, as they are there to support you throughout your journey.

Borderline Ovarian Cancer: Diagnosis and Staging

Diagnosing borderline ovarian cancer involves a series of tests similar to those used for other ovarian cancers:

  • Imaging Tests: Ultrasounds, CT scans, and MRIs help visualize the ovarian tumor and assess its size and extent. There is currently no definitive way to confirm a diagnosis without a biopsy. At Not These Ovaries, we are funding research to identify ways to diagnose ovarian cancer. 
  • Surgical Biopsy: A gynecologic oncologist surgeon will typically obtain a tissue sample during surgery for an initial pathology report, but it can take up to two weeks to have a complete report. The biopsy results will confirm the diagnosis and provide more information about the tumor’s characteristics.

These tests are crucial in determining the location and spread of the tumor, which can help guide treatment decisions. It’s essential to discuss the results of these tests with your healthcare team to understand the extent of the disease fully.


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. 
  • Stage II: The tumor involves one or both ovaries with pelvic extension or primary peritoneal cancer. 
  • Stage III: The tumor involves one or both ovaries with microscopically confirmed peritoneal metastasis outside the pelvis and/or regional lymph node metastasis.
  • Stage IV: Distant metastasis beyond the peritoneal cavity. 

It’s important to note that while the staging system is the same, the prognosis and treatment options for BOTs may differ from those of invasive ovarian cancers. In most cases, surgery is the primary treatment for BOTs, and the extent of the surgery depends on the stage and the patient’s individual circumstances, such as their desire for fertility preservation.

Understanding the stage of your BOT is essential for determining the most appropriate treatment plan and discussing your prognosis with your healthcare team. However, it’s crucial to remember that BOTs generally have a more favorable prognosis than invasive ovarian cancers, and the treatment approach may be tailored accordingly.

Creating a Treatment Plan for Borderline Ovarian Cancer

The treatment of borderline ovarian cancer typically differs from that of malignant ovarian cancer due to its less aggressive nature.

  • Surgery: Surgery is the primary treatment, and the goal is to remove the tumor while preserving fertility whenever possible. Selecting a gynecologic oncologist surgeon will significantly impact patient outcomes. Research has shown that the surgery success rate statistically doubles if a gynecologic oncologist surgeon performs patient surgery compared to a general surgeon. 
  • Hysterectomy or Oophorectomy: In some cases, an ovarian cancer hysterectomy (referred to as debulking surgery to remove the cancer) or oophorectomy surgery (removal of one or both ovaries) may be recommended, especially if the disease is more advanced or if the patient has completed childbearing.
  • Chemotherapy: Unlike malignant ovarian cancer, chemotherapy is NOT recommended for borderline ovarian cancer. Surgery and ongoing surveillance are the current standard of care for borderline ovarian cancer. 
  • Second Opinion: With the rarity of a borderline ovarian cancer diagnosis, we strongly recommend you get a second opinion from another specialized physician. It is, unfortunately, commonly misdiagnosed as low-grade serous ovarian carcinoma (LGSOC).

The Emotional Rollercoaster

A borderline ovarian cancer diagnosis can evoke a mix of emotions similar to those experienced with other cancers:

  • Fear and Uncertainty: The uncertainty of the disease and its potential impact on fertility can be emotionally challenging. 
  • Coping Strategies: Seeking support from loved ones, mental health professionals, or support groups can provide valuable assistance in navigating these emotions.
  • Menopause: A hysterectomy in younger women will cause menopause quickly, as most gynecologic oncologists do not recommend hormone replacement therapy (HRT), which will have a material impact on the female patient. Learning essential menopause nutrition tips will help nourish your body and alleviate symptoms.

Support Systems and Resources

Building a solid 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 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.

While knowledge is power, action is the key to progress. But groundbreaking research doesn’t happen in a vacuum — it requires support from people who understand its critical importance. By contributing to our ovarian cancer research fund, you’re investing in hope, in futures, and in the potential to transform lives. Your support will help improve early detection methods, develop targeted treatments, and unravel the genetic mysteries of BOTs.

Ready to be part of the solution? Visit our Fund a Trial page and join us in this vital mission. You can also make a difference by giving to Not These Ovaries in your own way. Together, we can turn research into reality and hope into healing.