Ovarian cysts are fluid-filled sacs that develop on a woman’s ovary. They are very common and usually harmless. However, some ovarian cysts can be cancerous. Doctors use various tests and procedures to determine if an ovarian cyst is benign (non-cancerous) or malignant (cancerous).
What are the symptoms of an ovarian cyst?
Many ovarian cysts do not cause any symptoms. However, larger cysts can cause symptoms such as:
- Pelvic pain
- Dull ache in the lower abdomen or back
- Bloating or fullness
- Urinary frequency or urgency
- Irregular periods
- Pain or pressure during sex
- Difficulty emptying the bowels
These symptoms may come and go. They are usually more noticeable right before a menstrual period.
What types of ovarian cysts are more likely to be cancerous?
Most ovarian cysts are non-cancerous and go away on their own. However, there are certain types of cysts that have a higher risk of being or becoming cancerous. These include:
- Complex cysts – These cysts contain both solid material and fluid. The solid part could be cancerous.
- Cysts in postmenopausal women – Any ovarian cysts that develop after menopause have a higher cancer risk.
- Cysts over 5-10 cm large – Larger cysts are more likely to be cancerous than smaller cysts.
- Cysts that persist over 2-3 menstrual cycles – Benign cysts usually go away after 1-2 cycles. Persistent cysts may require further evaluation.
So if a woman has a complex, persistent, or large ovarian cyst, doctors will investigate further to determine if cancer is present.
What tests do doctors use to diagnose ovarian cysts?
Doctors use the following approaches to evaluate and diagnose ovarian cysts:
Medical History and Physical Exam
The doctor will ask about the patient’s symptoms, menstrual cycle, medication use, medical history, and family history of ovarian cysts or ovarian cancer.
They will perform a pelvic exam to check for an enlarged ovary or mass.
Blood Tests
Certain blood tests can help detect elevated levels of tumor markers like CA-125. High CA-125 may indicate ovarian cancer, but can also be caused by other conditions.
Ultrasound
An ultrasound uses sound waves to create images of the ovaries. It can show the size, shape, location and composition of ovarian cysts. Complex cysts are more likely to be cancerous.
CT Scan
A CT scan takes cross-sectional X-ray images of the abdomen and pelvis. It provides more detail than an ultrasound. CT scans help examine large cysts and nearby structures.
MRI Scan
An MRI uses magnets and radio waves to produce detailed images. An MRI gives the best visualization of soft tissues like the ovaries. It can characterize ovarian lesions and distinguish between benign and malignant features.
Laparoscopy
In this minor surgery, the doctor inserts a thin, lighted instrument through small incisions to examine the internal organs. Laparoscopy allows doctors to see ovarian cysts and take biopsies.
Biopsy
A biopsy involves removing fluid or tissue samples from the cyst and examining them under a microscope. This is the only way to confirm whether a cyst is cancerous. Doctors may perform a biopsy during laparoscopy or use a fine needle to extract a sample.
How do doctors determine if an ovarian cyst is cancerous?
Based on a woman’s symptoms, medical history, physical exam, imaging tests and biopsy results, doctors determine the likelihood that an ovarian cyst is cancerous.
Here are some key factors that indicate an increased risk of cancer:
- Postmenopausal woman – Ovarian cysts are very common before menopause. After menopause, cysts have a higher risk of being cancer.
- Elevated CA-125 blood levels – CA-125 is a protein produced by some ovarian cancer cells and may be elevated in women with malignant cysts.
- Complex cysts – Solid areas and thick septations seen on ultrasound or MRI may indicate cancerous tissue.
- Metastatic lesions – Advanced imaging can detect spread of ovarian cancer to distant sites.
- Ascites or fluid buildup – Malignant cysts can cause fluid accumulation in the abdomen.
- Fast growth – Rapidly enlarging ovarian cysts often raise suspicion of cancer.
- Abnormal biopsy – Microscopic examination can confirm cancerous cells.
- Family history – Genetic predisposition increases ovarian cancer risk.
However, sometimes there is uncertainty even after testing. In such cases, surgical removal of the cyst or ovary may be necessary. The entire mass can then be sent for pathology to confirm whether or not it is cancerous.
Can an ovarian cyst turn into cancer?
Most ovarian cysts do not become cancerous. However, some non-cancerous cysts can develop into ovarian cancer over time.
Certain types of cysts have a greater potential to eventually turn malignant. These include:
- Endometriomas – Cysts filled with endometrial tissue have about a 1% chance of becoming cancerous.
- Serous cystadenomas – These fluid-filled cysts carry a 5-10% ovarian cancer risk.
- Mucinous cystadenomas – The risk of these mucus-producing cysts turning into cancer is estimated to be 10%.
- Dermoid cysts – Mature cystic teratomas have a 1-2% chance of undergoing malignant transformation.
The transition from a benign cyst to invasive ovarian carcinoma is slow and occurs over several years. Regular monitoring of complex or persistent ovarian cysts allows early detection of any cancerous changes. Prompt surgical treatment is recommended if the cyst shows signs of becoming cancerous.
Can a ruptured ovarian cyst be cancerous?
Rupture of an ovarian cyst often causes sudden, severe abdominal or pelvic pain. A ruptured cyst usually resolves on its own without treatment. However, sometimes a ruptured cyst can be an indication of ovarian cancer.
Research shows that about 15% of ruptured ovarian cysts are found to be malignant. Cancerous cysts may be more prone to rupture because they grow and expand rapidly.
Factors that raise suspicion of cancer in a ruptured ovarian cyst:
- The woman is postmenopausal
- The rupture causes significant internal bleeding
- Rupture is accompanied by dizziness or fainting
- Persistent abdominal pain after rupture
- The cyst is over 5 cm large
- The woman has other ovarian cancer symptoms
- Ascites or fluid buildup is present
- A complex solid/fluid cyst is seen on imaging
If cancer is suspected, the doctor will order blood tests, imaging scans and surgical evaluation of the ruptured cyst. Prompt diagnosis is important, even if the cyst initially appears benign on ultrasound. Postmenopausal women with ruptured cysts should be particularly vigilant about follow-up.
What are the treatment options for cancerous ovarian cysts?
Treatment of cancerous ovarian cysts involves surgery and chemotherapy. The stage and grade of the tumor determine the approach:
Surgery
- Removal of the affected ovary (oophorectomy) and fallopian tube (salpingectomy)
- Hysterectomy – Removal of the uterus and other ovary/fallopian tube
- Surgical staging – Removal of lymph nodes, tissue samples, abdominal fluid to detect spread
- Debulking – Removing as much of large tumors as possible
If the cancer is advanced and spread beyond the ovaries, the goal is to surgically remove as much of the tumor burden as possible.
Chemotherapy
Chemo drugs kill cancer cells. Chemotherapy may be given:
- Before surgery to shrink the tumor
- After surgery to destroy any remaining cancer cells
- Alone to treat recurrent cancer that has spread
Combined surgery and chemotherapy provide the best outlook for treating malignant ovarian cysts.
What is the prognosis and survival rate for ovarian cyst cancer?
Prognosis and survival rates for ovarian cancer depend on the stage at diagnosis:
- Stage 1 – Cancer limited to one or both ovaries. 5-year survival rate is 70-89%.
- Stage 2 – Cancer has spread to pelvis/uterus. 5-year survival rate is 45%.
- Stage 3 – Cancer has spread to abdomen or lymph nodes. 5-year survival rate is 10-41%.
- Stage 4 – Cancer has metastasized more distantly. 5-year survival rate is less than 20%.
When detected in early stages, the 5-year survival rate for ovarian cancer is over 90%. But most cases are diagnosed in later stages when cancer has already spread.
Regular screening and prompt follow-up of complex ovarian cysts is key to early diagnosis and better outcomes. Women with a family history of ovarian cancer may consider preventive surgery to remove the ovaries and fallopian tubes. This can lower ovarian cancer risk by up to 90%.
Conclusion
Ovarian cysts are usually benign. But some types carry an increased risk of being or becoming cancerous. Doctors use a combination of imaging tests, bloodwork, physical examination and biopsy results to determine if a cyst is cancerous. Prompt surgical treatment and chemotherapy can improve prognosis and survival if ovarian cancer is found early. Monitoring of postmenopausal women and those with a family history is important to detect any cancerous changes in ovarian cysts at the earliest stage possible.