Does pregnancy increase the risk of breast cancer coming back (recurrence)?

Because many breast cancers are sensitive to estrogen, there has been concern that if you had been treated for breast cancer, high hormone levels during pregnancy might increase the chance of cancer coming back. But research has now shown that being pregnant does not increase a woman's risk of breast cancer returning. This is true if your tumor did not spread beyond the breast area and your treatment was successful. It is always best to discuss your personal case with your breast surgeon and medical oncologist.

Doctors often counsel women to wait at least 2 years after breast cancer therapy (surgery, radiation, or chemotherapy) before becoming pregnant. The 2-year period is used because most recurrences of breast cancer happen during that time.

Can sex cause cancer?

For most cancers, there is no link between a person's sex life and the risk of developing a tumor. Nor does having sex after cancer treatment increase the chances of cancer coming back or getting out of control. Viruses passed from one person to another through sexual contact may cause a few kinds of cancer, including squamous cell carcinoma of the cervix, vulva, vagina, penis, or rectum, and Kaposi sarcoma. Hepatitis B and hepatitis C viruses, which can be passed from one person to another during sex, can increase the risk for liver cancer. Epstein-Barr virus, which causes mononucleosis (also called the "kissing disease"), seems to increase the risk of certain other types of cancer, too.

These cancers are not caused by having sex itself, but by viruses that can be picked up during sexual activity with someone who already has the virus. News stories about viruses and cancer can be confusing. The roles of these viruses are not fully understood, but some can cause changes in the DNA of the cell. Most people who get these viruses never develop cancer. For more information about viruses and cancer, call our toll-free number, 1-800-ACS-2345 (1-800-227-2345) and ask for our document, Infectious Agents and Cancer.

There are other risk factors involved in cancer development, even in those cancers that are promoted by viruses. Women who smoke cigarettes, for example, have a higher risk of cervical cancer. Women who start having sex before age 18 also seem at higher risk for cancer of the cervix.

Many patients and their partners worry that cancer is contagious. Despite this myth, a cancer cell from one person's body simply cannot take root and grow in someone else. Not only are all cells fragile, needing the proper environment to survive, but the partner's immune system would detect the cancer cell and destroy it. Cancer is not contagious.

Can AIDS be picked up from sex?

The virus that causes AIDS is called the human immunodeficiency virus (HIV). It can be passed to someone else when semen, vaginal secretions, or blood from an infected person get into the body of an uninfected person. This can happen during oral, vaginal, or anal sex. This virus can be passed on in 3 ways:

• unprotected sex with an infected person
• sharing an infected person's needle during drug or steroid use
• from a mother to her baby during pregnancy or breast-feeding

Most people with HIV do not look sick until they have had the virus for many years. During that time, the only way to find out whether they have the virus is to take an HIV test. Unless you know for sure that neither you nor your sexual partner has the virus, and that both of you are careful to avoid infection, you should practice safer sex. Examples of safer sex include:

• Touching each other's genitals with the hands.

• Oral sex with a man if he wears a condom from start to finish. A woman should never taste or swallow a man's semen if she suspects he might have HIV.

• Oral sex with a woman if a "dental dam" is used. A dental dam is a rubber sheet that is used to cover the woman's vulva during oral sex. Or a sheet of plastic kitchen wrap that keeps the woman's sexual fluids contained can be used instead.

• Vaginal intercourse or anal intercourse wearing a condom. Condoms only work if they are used correctly, every time, from start to finish. Lots of water-based lubricant can help reduce the risk of the condom breaking. Never use lotion, oils, or petroleum jelly, which weaken latex condoms.

Can sex during treatment be harmful to a patient or partner?

Cancer treatment does not make sex dangerous. Having sex with you will not expose your partner to radiation under most circumstances, but you should check with your doctor to be sure. A few chemotherapy drugs can be present in small amounts in semen or vaginal fluids. You may want to use condoms while you are getting chemotherapy and for about 2 weeks afterward. Talk to your doctor or nurse if you have specific questions or concerns.

Keep in mind that some cancer treatments may cause harm to the fetus if you get pregnant. Talk with your doctor about what kind of birth control will work best for you, and how long you will need to use it after treatment. Condoms alone are not likely to be effective enough for birth control during chemotherapy, radiation, or other types of cancer treatment.

When should a person with cancer not have sex?

Ask your doctor if sexual activity would cause a problem with your treatment. Here are some general guidelines to consider:

• During recovery from surgery, intercourse can cause bleeding or strain the incision. Sex may also raise your chance of an infection. The time between your surgery and when it is safe to resume your sex life varies. This depends on the type of operation and your rate of healing. Your surgeon can tell you when it would be safe to try sexual activity again.

• Some types of cancer, like cancer of the cervix or bladder, may cause bleeding in the genital area or urinary tract. If this bleeding becomes heavier after sex, talk with your doctor about it. You may need to stop having intercourse until the bleeding has stopped and the area has healed.

• During chemotherapy, a person with an infusion catheter sometimes worries that sexual activity will harm it. As long as you take care not to rub against the dressing, sex should not cause a problem.

• When you are being treated for cancer, there are often times when your immune system is not working as well as it should. This may happen during radiation therapy or chemotherapy. At such times, it may be easier for you to get all kinds of infections. Again, ask your doctor if sexual contact poses too much of a threat for infection. Most doctors say that if you are well enough to be out in public, you are well enough to have sex. If you are in the hospital because of weak immunity, ask your doctor's advice on kissing, cuddling, or sexual touching.

• Some of the bacteria that can start an infection in the urinary tract or genital area can be washed away by urinating a few minutes after sex. Some doctors also suggest washing the genital area before sex and drinking extra fluids. If you have urinary tract infections often, your doctor may give you antibiotics you can take after intercourse. This can help prevent infection.

• If you notice any sores, bumps, or warts on your partner's penis or a white or greenish-grey fluid (other than semen) in the opening at the tip, you should ask for an explanation of the symptom and decide whether it is safe to have sex.

• You can greatly reduce your chances of getting a sexually transmitted disease (STD) if your partner wears a condom from start to finish, each time you have sex.

• The sperm-killing chemicals in contraceptives were once thought helpful in fighting bacteria and some viruses. But some studies showed a higher risk of getting HIV infection in women who used nonoxynol-9 (N-9), a popular ingredient in foam and gel contraceptives. Some lubricated condoms also have N-9, so you may want to check the label before you use them. Also, if a woman's vagina is irritated or dry from chemotherapy, contraceptive foams, jellies, or films may make the problem worse and be painful. Water-based lubricants or vaginal moisturizers may be used to help with dryness. (See "Vaginal dryness" in the section "Ways of dealing with sexual problems") Talk with your doctor about what methods might meet your needs for preventing STDs or pregnancy.

You probably have many other questions that haven't been addressed here. Don't be afraid or embarrassed to discuss them with your doctor or other members of your health care team. Write them down now so you'll remember to ask them at your next visit.

Last Medical Review: 11/10/2008
Last Revised: 11/10/2008