Ovarian Cancer vs. Ovarian Cysts

Picture of the Female Reproductive System

• Ovarian cancer is a malignant tumor arising in the ovaries or nearby tissues in women. This group of cancers includes epithelial ovarian (from the cells on the surface of the ovary), fallopian tube, and primary peritoneal (the lining inside the abdomen that coats many abdominal structures) cancers.
• Ovarian cysts are closed, sac-like structures within the ovary that are filled with a liquid or semisolid substance.
• Both ovarian cancer and ovarian cysts typically do not produce symptoms until they are very large or when the cancer has advanced. When this occurs, they may share similar signs and symptoms, for example:
  • Pelvic pain or lower abdominal pressure
  • Pain with sexual intercourse
  • Abdominal bloating
• It is impossible to tell the difference between ovarian cysts and ovarian cancer from the symptoms alone, but ovarian cysts are much more common.
• Ovarian cysts are often identified when an ultrasound examination is performed for another reason.
• It is unclear what causes ovarian cancer, but risk factors include a family history of the condition and mutations in certain genes.
• Ovarian cysts are caused by multiple factors including the menstrual cycle, endometriosis, and benign tumors.

Ovarian Cancer

The term ovarian cancer includes several different types of cancer (uncontrolled division of abnormal cells that can form tumors) that all arise from cells of the ovary. Most commonly, tumors arise from the epithelium, or lining cells, of the ovary. These include epithelial ovarian (from the cells on the surface of the ovary), Fallopian tube, and primary peritoneal (the lining inside the abdomen that coats many abdominal structures) cancers. These are all considered one disease process. There is also an entity called ovarian low malignant potential tumor; these tumors have some of the microscopic features of a cancer, but tend not to spread like typical cancers.

Less common forms of ovarian cancer come from within the ovary itself, including germ cell tumors and sex cord-stromal tumors.

Ovarian Cysts

Ovarian cysts are small fluid-filled sacs that develop in a woman's ovaries. Most cysts are harmless, but some may cause problems such as rupture, bleeding, or pain. Moreover, surgery may be required in certain situations to remove the cyst(s). It is important to understand the function of the ovaries and how these cysts develop.

Ovarian Cancer Symptoms and Signs

Ovarian cancer is difficult to diagnose because symptoms often do not occur until late in the disease. Symptoms do not occur until the tumor has grown large enough to apply pressure to other organs in the abdomen, or until the cancer has spread to remote organs. The symptoms are nonspecific, meaning they could be due to many different conditions. Cancer is not usually the first thing considered in a woman having symptoms.

The only early symptom of the disease can be menstrual irregularity. Symptoms that come later include:

• Pelvic pain or pressure
• Pain with intercourse
• Abdominal swelling and bloating
• Urinary frequency
• Constipation
• Ascites: Collection of fluid in the abdomen, contributing to abdominal distension and shortness of breath
• Loss of appetite
• Feeling full after eating little
• Gas and/or diarrhea
• Nausea and vomiting

Ovarian Cysts Symptoms and Signs

Usually, ovarian cysts do not produce symptoms and are found during a routine physical exam. They also may be seen as an incidental finding on an ultrasound performed for other reasons. However, symptoms can be present, especially with large cysts or ruptured cysts. These are variable and may include:

• Pain with sexual intercourse, especially with deep penetration
• Lower abdominal or pelvic pain. This may be intermittent, or can be severe, sudden, and sharp
• A feeling of lower abdominal or pelvic pressure or fullness
• Chronic pelvic pain or low back pain throughout the menstrual cycle
• Pelvic pain following exercise or vigorous activity
• Pain or pressure with urination or bowel movement
• Nausea and vomiting
• Vaginal pain or spotty bleeding from the vagina
• Infertility
• Problems having bowel movements
• Feeling pressure to have a bowel movement
• Abdominal tenderness
• Abdominal distension
• Bloating
• Feeling of abdominal fullness
• Heartburn
• Indigestion
• Feeling full early when eating
• Problems with the control of urination

A ruptured ovarian cyst typically causes severe pain that comes on suddenly. This most commonly occurs in the mid-menstrual cycle and often happens following sexual intercourse or exercise.

Causes of Ovarian Cancer

In most instances of ovarian cancer, there is no identifiable cause; however, family history does play a role.

• The lifetime risk for U.S. women of developing ovarian cancer is low.
• If one first-degree relative -- a mother, sister, or daughter -- has the disease, the risk increases.
• The risk can climb to 50% if two first-degree relatives have the disease.
• If a woman has ovarian cancer and her daughter develops ovarian cancer, the daughter will probably develop the cancer at a relatively young age (younger than 60 years old).

Ovarian cancer has been linked with three hereditary syndromes.

1. Breast-Ovarian Cancer Syndrome

• Breast-ovarian syndrome is a mutation in a gene called BRCA1 that has been linked to an increased risk of both breast and ovarian cancer. Some women who have this mutation develop ovarian cancer.
• Another mutation involving the BRCA2 gene increases the risk of ovarian cancer, but to a lesser degree. These mutations are hereditary, meaning that they can be passed from one generation to the next.

Clues that may indicate the presence of these mutations include:

• Family members who have ovarian cancer or breast cancer (especially those who are diagnosed with these cancers when younger than 50 years)
• A relative with both breast and ovarian cancer or a male relative with breast cancer.

Development of more precise estimates of cancer risk and better genetic testing for carriers of these genes is taking place.

2. Hereditary Nonpolyposis Colorectal Cancer (HNPCC) Syndrome (Lynch Syndrome II)

Hereditary nonpolyposis colorectal cancer is a genetic syndrome that has been dubbed "family cancer syndrome," and is associated with colon cancer developing in people younger than 50 years old. Other organs that can be involved include the uterus, ovary, breast, stomach, and pancreas.

A mutated gene causes hereditary nonpolyposis colorectal cancer. Women with the syndrome have a chance of developing ovarian cancer.

3. Site-Specific Ovarian Cancer Syndrome

Site-specific ovarian cancer syndrome is the least common of the three syndromes, and experts do not know much about it yet. This syndrome may be due to mutations of the BRCA1 gene.

Other Factors That Increase Ovarian Cancer Risk

• Age greater than 50 years
• No pregnancies
• Use of fertility drugs: Some studies have shown that the use of fertility drugs increases the risk of ovarian cancer, but study results have not been consistent.
• Ashkenazi Jewish heritage
• European (white) heritage: White women are much more likely to have ovarian cancer than African American women are.
• Asbestos exposure
• Repeated exposure of the genitals to talc
• Irradiation of the pelvic area
• Some viruses, especially the virus that causes mumps

Some research suggests that estrogen may promote ovarian cancer in women who have been through menopause. For years, the cancer risks involved with using hormone replacement therapy divided the medical community. Research findings in 2002 and early 2003 showed that hormone replacement therapy does not provide many of the benefits it was believed to have, and it increases the risk of heart disease. Experts no longer routinely recommend long-term hormone replacement therapy for most women, though the issue can be considered on a case-by-case basis.

What Decreases the Risks of Ovarian Cancer?

• Any factor that inhibits ovulation (release of an egg from the ovary) seems to protect against development of ovarian cancer. This may be because ovulation disrupts the epithelial layer of the ovary. As cells divide to repair the damage, uncontrolled division and malignant changes may occur.
• Term pregnancy (lasting the full nine months) significantly reduces the risk of ovarian cancer. As the number of pregnancies increases, the risk of ovarian cancer decreases.
• Use of oral contraceptives (birth control pills) reduces the risk of ovarian cancer.
• Breastfeeding lowers risk of ovarian cancer, and the risk decreases with increasing duration of breastfeeding.
• Removal of the ovaries before cancer reduces the risk of cancer arising in the ovaries to zero. However, cases of a closely related condition called primary peritoneal carcinoma due to embryonic remnants of ovarian formation can still occur. This may be a consideration in women with inherited cancer risks. Experts should base this decision on genetic testing and counseling.
• Having the woman's "tubes tied" (tubal ligation) to prevent pregnancy.
• Having a hysterectomy lowers the risk of ovarian cancer.

Causes of Ovarian Cysts

Rsk factors for developing ovarian cysts include:

• History of previous ovarian cysts
• Irregular menstrual cycles
• Obesity
• Infertility
• Infertility treatment with gonadotropin medications
• Hypothyroidism
• Tamoxifen (Soltamox) therapy for breast cancer
• Oral contraceptive/birth control pill usage decreases the risk of developing ovarian cysts, because they prevent ovulation.

Most ovarian cysts are benign (non-cancerous); however, rarely, ovarian cysts may be related to ovarian cancers.

When to Call a Doctor If You Have Ovarian Cancer Symptoms and Signs

If you are experiencing abdominal pain, distension, or bloating that is not explained by simple constipation, lactose intolerance, or another harmless condition, call a doctor or other healthcare professional right away.

If you are older than 40 years or have a family history of breast or ovarian cancer, these symptoms should be attributed to constipation or other conditions only after a doctor has ruled out the possibility of ovarian cancer.

• Severe abdominal pain
• Abdominal pain with fever
• Continuous vomiting or diarrhea (especially with blood)
• Difficulty breathing
• Abnormal vaginal bleeding
• Weakness, dizziness, feeling faint or fainting especially while standing from sitting (hypotension, low blood pressure)
• Persistent fever
• Severe lower abdominal or pelvic pain
• High or low blood pressure unrelated to medications
• Excessive thirst or urination
• Unexplained shoulder pain combined with abdominal pain
• Persistent nausea and vomiting

When to Call a Doctor If You Have Ovarian Cysts Symptoms and Signs

See a doctor or other healthcare professional if you have these symptoms:

• Fever
• Abnormal pain or tenderness in the abdominal or pelvic area
• Nausea or vomiting
• Weakness, dizziness, or fainting
• Pallor or anemia (possibly from loss of blood)
• Abnormally heavy or irregular menstruation
• Abdominal swelling or unusual increased abdominal girth
• Abdominal pain in patient's taking blood thinners such as warfarin (Coumadin, Jantoven)
• Increased facial hair
• Excessive thirst or urination
• Unexplained weight loss
• A noticeable abdominal or pelvic mass