What is prevention?

Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.

To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.

Different ways to prevent cancer are being studied, including:

• Changing lifestyle or eating habits.
• Avoiding things known to cause cancer.
• Taking medicines to treat a precancerous condition or to keep cancer from starting.

General Information About Ovarian, Fallopian Tube, and Primary Peritoneal Cancer

KEY POINTS

• Ovarian, fallopian tube, and primary peritoneal cancers are diseases in which malignant (cancer) cells form in the ovaries, fallopian tubes, or peritoneum.
• Ovarian cancer is the leading cause of death from cancer of the female reproductive system.

Ovarian, fallopian tube, and primary peritoneal cancers are diseases in which malignant (cancer) cells form in the ovaries, fallopian tubes, or peritoneum.

The ovaries are a pair of organs in the female reproductive system. They are in the pelvis, one on each side of the uterus (the hollow, pear-shaped organ where a fetus grows). Each ovary is about the size and shape of an almond. The ovaries make eggs and female hormones (chemicals that control the way certain cells or organs work in the body).

The fallopian tubes are a pair of long, slender tubes, one on each side of the uterus. Eggs pass from the ovaries, through the fallopian tubes, to the uterus. Cancer sometimes begins at the end of the fallopian tube near the ovary and spreads to the ovary.

The peritoneum is the tissue that lines the abdominal wall and covers organs in the abdomen. Primary peritoneal cancer is cancer that forms in the peritoneum and has not spread there from another part of the body. Cancer sometimes begins in the peritoneum and spreads to the ovary.

Anatomy of the female reproductive system. The organs in the female reproductive system include the uterus, ovaries, fallopian tubes, cervix, and vagina. The uterus has a muscular outer layer called the myometrium and an inner lining called the endometrium.

Ovarian cancer is the leading cause of death from cancer of the female reproductive system.

Ovarian cancer is most common in postmenopausal women. New cases of ovarian cancer and deaths from ovarian cancer are higher among white women than black women, but have decreased in both groups.

Women who have a family history of ovarian cancer and/or certain inherited gene changes, such as BRCA1 or BRCA2 gene changes, have a higher risk than women who do not have a family history or who have not inherited these gene changes. For women with inherited risk, genetic counseling and genetic testing can be used to find out more about how likely they are to develop ovarian cancer.

It is hard to find ovarian cancer early. Early ovarian cancer may not cause any symptoms. When symptoms do appear, ovarian cancer is often advanced.

Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Prevention

KEY POINTS

• Avoiding risk factors and increasing protective factors may help prevent cancer.
• The following are risk factors for ovarian, fallopian tube, and primary peritoneal cancer:
  • Family history of ovarian, fallopian tube, and primary peritoneal cancer
  • Inherited risk
  • Hormone replacement therapy
  • Weight and height
  • Endometriosis
• The following are protective factors for ovarian, fallopian tube, and primary peritoneal cancer:
  • Oral contraceptives
  • Tubal ligation
  • Giving birth
  • Salpingectomy
  • Breastfeeding
  • Risk-reducing salpingo-oophorectomy
• It is not clear whether the following affect the risk of ovarian, fallopian tube, and primary peritoneal cancer:
  • Diet
  • Alcohol
  • Aspirin and non-steroidal anti-inflammatory drugs
  • Talc
  • Infertility treatment
• Cancer prevention clinical trials are used to study ways to prevent cancer.
• New ways to prevent ovarian, fallopian tube, and primary peritoneal cancer are being studied in clinical trials.

Avoiding risk factors and increasing protective factors may help prevent cancer.

Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

The following are risk factors for ovarian, fallopian tube, and primary peritoneal cancer:

Family history of ovarian, fallopian tube, and primary peritoneal cancer

A woman whose mother or sister had ovarian cancer has an increased risk of ovarian cancer. A woman with two or more relatives with ovarian cancer also has an increased risk of ovarian cancer.

Inherited risk

The risk of ovarian cancer is increased in women who have inherited certain changes in the BRCA1, BRCA2, or other genes.

The risk of ovarian cancer is also increased in women who have certain inherited syndromes that include:

• Familial site-specific ovarian cancer syndrome.
• Familial breast/ovarian cancer syndrome.
• Hereditary nonpolyposis colorectal cancer (HNPCC; Lynch syndrome).

Hormone replacement therapy

There is a slightly increased risk of ovarian cancer in women who are taking hormone replacement therapy (HRT) after menopause. There is also an increased risk of ovarian cancer in women who have recently used HRT, even if they used it for less than 5 years. The risk of ovarian cancer is the same for HRT with estrogen only or with combined estrogen and progestin. When HRT is stopped, the risk of ovarian cancer decreases over time. The risk of ovarian cancer is not affected by the age of the woman when taking HRT.

Weight and height

Being overweight or obese is linked to an increased risk of ovarian cancer. Being obese is also linked to an increased risk of death from ovarian cancer. Being tall may also be linked to a slight increase in the risk of ovarian cancer.

Endometriosis

Women who have endometriosis have an increased risk of ovarian cancer.

The following are protective factors for ovarian, fallopian tube, and primary peritoneal cancer:

Oral contraceptives

Taking oral contraceptives (“the pill”) lowers the risk of ovarian cancer. The longer oral contraceptives are used, the lower the risk may be. The decrease in risk may last up to 30 years after a woman has stopped taking oral contraceptives.

Taking oral contraceptives increases the risk of blood clots. This risk is higher in women who also smoke.

Tubal ligation

The risk of ovarian cancer is decreased in women who have a tubal ligation (surgery to close both fallopian tubes).

Giving birth

Women who have given birth have a decreased risk of ovarian cancer compared to women who have not given birth. Giving birth to more than one child further decreases the risk of ovarian cancer.

Salpingectomy

Some studies have shown that salpingectomy (surgery to remove one or both fallopian tubes) is linked with a decreased risk of ovarian cancer. When both fallopian tubes are removed, the risk of ovarian cancer is lowered more than when one fallopian tube is removed.

Breastfeeding

Breastfeeding is linked to a decreased risk of ovarian cancer. The longer a woman breastfeeds, the lower her risk of ovarian cancer. Women who breastfeed for at least 8 to 10 months have the greatest decrease in risk of ovarian cancer.

Risk-reducing salpingo-oophorectomy

Some women who have a high risk of ovarian cancer may choose to have a risk-reducing salpingo-oophorectomy (surgery to remove the fallopian tubes and ovaries when there are no signs of cancer). This includes women who have inherited certain changes in the BRCA1and BRCA2 genes or have an inherited syndrome.

It is very important to have a cancer risk assessment and counseling before making this decision. These and other factors may be discussed:

• Infertility.
• Early menopause: The drop in estrogen levels caused by removing the ovaries can cause early menopause. Symptoms of menopause include the following:
  • Hot flashes.
  • Night sweats.
  • Trouble sleeping.
  • Mood changes.
  • Decreased sex drive.
  • Heart disease.
  • Vaginal dryness.
  • Frequent urination.
  • Osteoporosis (decreased bone density).
  These symptoms may not be the same in all women. Hormone replacement therapy (HRT) may be used to lessen these symptoms.
• Risk of ovarian cancer in the peritoneum: Women who have had a risk-reducing salpingo-oophorectomy continue to have a small risk of ovarian cancer in the peritoneum (thin layer of tissue that lines the inside of the abdomen). This is rare, but may occur if ovarian cancer cells had already spread to the peritoneum before the surgery or if some ovarian tissue remains after surgery.

It is not clear whether the following affect the risk of ovarian, fallopian tube, and primary peritoneal cancer:

Diet

Studies of dietary factors have not found a strong link to ovarian cancer.

Alcohol

Studies have not shown a link between drinking alcohol and the risk of ovarian cancer.

Aspirin and non-steroidal anti-inflammatory drugs

Some studies of aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) have found a decreased risk of ovarian cancer and others have not.

Talc

Studies of women who used talcum powder (talc) dusted on the perineum (the area between the vagina and the anus) have not found clear evidence of an increased risk of ovarian cancer.

Infertility treatment

Overall, studies in women using fertility drugs have not found clear evidence of an increased risk of ovarian cancer. The risk of invasive ovarian cancer may be higher in women who do not get pregnant after taking fertility drugs.

Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.

The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.

New ways to prevent ovarian, fallopian tube, and primary peritoneal cancer are being studied in clinical trials.

Information about clinical trials supported by NCI can be found on NCI’s clinical trials search webpage. Clinical trials supported by other organizations can be found on the ClinicalTrials.gov website.