Low-Grade Serous Ovarian Cancer (LGSOC)
What is LGSOC?
Low-grade serous ovarian cancer (also known as LGSOC) is a rare and serious ovarian cancer. It is distinct and different from the more common high-grade serous ovarian cancer (also known as HGSOC). LGSOC is likely to come back after initial treatment.
Low-grade serous ovarian cancer starts in the thin layer of tissue around the ovaries (also known as the epithelium) and can grow persistently.
Low-grade means that the cancer cells look a lot like normal cells.
Serous means that the cancer started in the serous membrane, which is part of the epithelium.
LGSOC affects younger people
LGSOC affects people at a broad range of ages, with large numbers between 20-30 years old and 50-60 years old. The average age of diagnosis for LGSOC happens around 43-48 years old.
LGSOC is a rare cancer
About 5%
of all serous ovarian cancers are LGSOC
Nearly 2,000
new cases are diagnosed in the US each year
Distinguishing LGSOC from HGSOC
LGSOC and HGSOC are two distinct and different cancers.
LGSOC
HGSOC
Uncommon
About 5% of serous ovarian cancers
Very common
About 95% of serous ovarian cancers
Affects younger people
The average age at diagnosis is 43-48 years, but has been diagnosed in people as young as 14 years old
Affects older people
Most people are over 60 years old when diagnosed
Normal-looking cells
Cells look like non-cancer cells
Abnormal-looking cells
Cells look unstructured or underdeveloped
Grows slowly
Cancerous cells grow slowly but persistently
Grows quickly
Cancerous cells grow quickly
Progresses slowly
Can start as benign (non-cancerous) before becoming cancerous and spreading
Progresses rapidly
Spreads quickly outside of ovaries
Less sensitive to chemotherapy
Other treatments may be required
Usually responds to chemotherapy
Responsive to chemotherapy, which can slow/stop the spread of cancer
LGSOC symptoms
At first diagnosis and at recurrence, low-grade serous ovarian cancer (LGSOC) symptoms are similar to other cancers and different diseases, like irritable bowel syndrome. That’s why LGSOC may be overlooked and take a long time to diagnose.
The symptoms of LGSOC are SERIOUS*
Stomach bloating
Eating less because you feel full
Repeated changes to bowel movements
Intense back and pelvic pain
Ongoing for up to 2 weeks
Urgent need to urinate
Stomach pain
*This list is not exhaustive, as these are not all of the symptoms of LGSOC. Discuss any and all symptoms that you feel may be related to LGSOC with your doctor.
Diagnosing LGSOC
Because the symptoms of LGSOC are similar to other diseases, like irritable bowel syndrome and chronic gastrointestinal issues, it can be difficult to diagnose. It can take as long as 3 years for patients to receive an accurate diagnosis of LGSOC.
- Up to 90% of patients with LGSOC are diagnosed at an advanced stage
- LGSOC is confirmed through a biopsy done by a pathologist, who may also perform what’s called germline and somatic testing to help your doctor guide treatment decisions
- If there has been no specific diagnosis for your type of ovarian cancer, consider getting a second opinion with a gynecologic oncologist with LGSOC experience
“Getting a second opinion is really important, especially for LGSOC, because it’s such a rare condition.”
–Kat, person living with LGSOC
Initial tumor detection
An initial diagnosis for LGSOC typically begins with a combination of pelvic imaging (like CT or MRI scans) and blood tests, such as CA-125. If these tests indicate a suspicious ovarian mass, a surgical tissue biopsy is required to confirm the diagnosis.
Confirming LGSOC
To confirm an LGSOC diagnosis, your healthcare provider will take a small sample of tissue from your tumor that another healthcare provider (called a pathologist) will then test to confirm an LGSOC diagnosis. They may also perform additional testing to detect changes and mutations in your cancer cells.
What recurrence means in LGSOC
Recurrence means that cancer has come back after previous treatment. More than 80% of patients with LGSOC experience recurrence.
Experts recommend regular monitoring and routine follow-ups after diagnosis. This is important for the detection and management of any recurrence you may experience. Report any changes to your health or concerns about how you feel to your healthcare provider.
If recurrence is confirmed, your doctor may do genetic testing to determine whether genetic mutations are present in your cancer cells.
About mutations
Mutations that drive cancer growth can be inherited, or they may occur locally. Sometimes local mutations occur during the course of cancer treatment. Detecting mutations in cancer cells is an important step in treatment as it provides insight to finding targeted therapies.
Common mutations in LGSOC are the KRAS, BRAF, and NRAS mutations. Some mutations are detectable using blood tests, while other use tissue biopsies from tumors.
About KRAS mutations
The KRAS gene mutation occurs in about 30% of LGSOC cases and is the most common type of mutation seen with LGSOC.
Mutations can cause a gene to act like a switch stuck in the “on” position, triggering the continuous growth of cancer cells.
