Low-grade serous ovarian cancer (LGSOC) presents differently than the more common high-grade serous carcinoma. It tends to show up in younger people, grows slowly, and has higher survival rates.

LGSOC is a rare form of ovarian cancer. The average age of a person at diagnosis is 55.5 years, which is notably lower than the average of 62.6 years for high-grade serous cancer. About 8 in 10 people receive a diagnosis at an advanced stage.

The American Cancer Society estimates that in 2024, around 19,680 people in the United States will receive a diagnosis of ovarian cancer, and around 12,740 people are likely to die from this condition.

This article explores the symptoms, prevalence, diagnosis, risk factors, treatment, and outlook of low-grade serous ovarian cancer, as well as some frequently asked questions.

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LGSOC is a rare, slow-growing subtype of serous ovarian cancer. It starts in the epithelial cells, which are the cells covering the outer surface of the ovaries.

About 9 in 10 ovarian cancers are epithelial cell tumors, also known as carcinomas, with the serous subtype being the most common.

Doctors classify epithelial ovarian cancers into different types. The other main types of ovarian cancer include:

  • Endometrioid carcinoma: This is the second most common type (52%) of epithelial ovarian cancer and has links to endometriosis.
  • Clear cell carcinoma: This is a rare form (6%) of ovarian cancer that can have links to endometriosis. Chemotherapy is less effective at treating this form of cancer.
  • Mucinous carcinoma: This rare form (6%) of ovarian cancer can be difficult to diagnose. Mucinous tumors can be noncancerous (benign), borderline, or cancerous (malignant).

Each type of ovarian cancer also receives a grade on the basis of how much the tumor cells look like noncancerous tissue.

Doctors class LGSOC as “low grade”, or grade 1. This grade indicates that the cancer cells are less aggressive and progress at a slower rate than high-grade serous ovarian carcinoma (HGSOC), which is grade 3.

Low-grade carcinomas tend to have a better outlook.

As well as the type and grade, the stage of ovarian cancer is important, as it helps specialists decide what treatment a patient may need. The stage of a cancer describes how far the cancer has grown. In epithelial ovarian cancers, there are 4 stages, from 1 to 4.

LGSOC is a slow-forming cancer and sometimes does not cause any symptoms when it first develops. When symptoms do occur, they can be similar to those present in other types of ovarian cancer.

Recognizing these symptoms is crucial for early detection. However, the signs of LGSOC can be vague and similar to other conditions, making diagnosis challenging.

Symptoms may include:

  • pelvic or abdominal pain
  • swelling
  • bloating
  • feeling full quickly
  • changes in bowel habits
  • needing to urinate often

Diagnosis often involves a combination of imaging and diagnostic tests, including:

A definitive diagnosis typically requires a surgical procedure, during which a doctor takes a biopsy and examines it under a microscope.

LGSOC accounts for around 2–5% of cases of ovarian cancer overall and 5–10% of cases of serous ovarian cancer.

Despite being rare, its impact on affected individuals is significant.

The rarity of this subtype has led to ongoing research efforts to better understand its molecular and genetic characteristics, paving the way for more targeted treatments.

The treatment and management of LGSOC often involves a multifaceted approach as it does not respond well to chemotherapy.

Initial treatment usually involves surgery to remove as much of the tumor as possible. Afterward, an oncologist may recommend chemotherapy or radiation to target remaining cancer cells.

In recent years, new clinical trials have shown promise in treating LGSOC. A 2022 study found that participants who received a targeted drug lived longer without their cancer progressing than those who received standard treatment.

Identifying potential risk factors for LGSOC is an ongoing area of research.

Some of the common risk factors for LGSOC are:

The outlook for individuals with LGSOC varies depending on factors such as the stage at diagnosis and the effectiveness of treatment.

Generally, LGSOC has a more positive outlook than HGSOC, primarily due to its slower growth rate. However, the potential for the cancer to come back highlights the importance of long-term monitoring and follow-up care.

Below are commonly asked questions about low-grade serous ovarian cancer:

What is the survival rate?

The survival rate for LGSOC is generally higher than for high-grade serous ovarian cancer.

However, individual outcomes vary, and survival rates depend on factors such as the stage of diagnosis and the response to treatment.

Can it be cured?

Achieving a complete cure for LGSOC is challenging, but with timely and comprehensive treatment, many individuals can achieve long-term remission and lead fulfilling lives.

Ongoing research into innovative therapies continues to improve the outlook for those with an LGSOC diagnosis.

What causes it?

The exact causes of LGSOC remain unknown.

While genetic factors and family history may play a role, researchers are actively investigating the molecular and genetic origins of this type of cancer.

Low-grade serous ovarian cancer is a rare subtype of ovarian cancer that can affect females from the age of 19 and above.

While it is a slow-forming type of cancer, early detection and understanding its distinct characteristics, risk factors, and treatment options are crucial for accurate diagnosis and effective management.

Ongoing research aims to improve outcomes for individuals with this subtype of ovarian cancer.