Pregnancy causes many changes in the breast, including the development of new lumps and bumps. Pregnancy changes in the breast make it difficult to assess whether new lumps have developed. While rare, breast cancer can occur in pregnancy, affecting between 1 in 3,000 and 1 in 10,000 women, reports Imaginis, an independent resource developed and managed by physicians specializing in women's health issues. Breast cancer occurs more frequently in women who postpone pregnancy until their late 30s or 40s.
Normal Changes
Breasts enlarge during pregnancy and often feel tender and lumpy. This can create anxiety in pregnant women if normal pregnancy breast changes are mistaken for cancerous lumps. Clogged milk ducts in pregnancy can cause hard, lumpy, tender reddened areas, the American Pregnancy Association states.
Evaluation
On the other hand, new lumps can develop during pregnancy and should not be dismissed as just another pregnancy change. Higher levels of estrogen during pregnancy may increase growth in an estrogen-dependent tumor, one that grows in the presence of estrogen. Self-examination breast exams should continue once a month to detect new lumps, and any changes should be reported to medical personnel. Between 70 to 80 percent of lumps that develop during pregnancy are not cancerous, BreastCancer.org explains.
Testing
Ultrasound can distinguish between cysts, fluid-filled areas in the breast and solid tissue, which could be cancerous. Mammogram, done with proper shielding of the abdomen, is used to follow up on an abnormal ultrasound. Mammograms can't detect cancers in pregnant women as well as non-pregnant women, however. While 85 percent of cancerous lumps are normally detected in non-pregnant women, only between 62 and 78 percent are detected in pregnant women, according to BreastCancer.org. Biopsy, where fluid is drawn out of the suspicious area with a needle and viewed under the microscope for changes, can safely be done in pregnancy, but rapidly dividing breast cells that occur normally in pregnant women may be mistaken for cancerous cells.
Treatment
A diagnosis of breast cancer does not mean the pregnancy must be terminated. The cancer itself does not appear to harm the pregnancy, although treatment options may be somewhat limited if the pregnancy continues. Some of the treatments and tests can cause harm to the developing fetus, however. Treatment should not be delayed, unless the woman is within two to three weeks from her due date, Imaginis advises.
Chemotherapy in the second or third trimester appears to cause few short-term complications in the fetus, although long-term complications aren't well studied. Mastectomy is usually performed in the first or second trimester. During the third trimester, mastectomy or lumpectomy may be done, and chemotherapy or radiation are postponed until after delivery.
Considerations
Breast cancer can occur during pregnancy, although odds are that any new lumps are not cancerous. A diagnosis of breast cancer in the first trimester requires serious consideration of the risks and benefits of possible treatment on the fetus, if the woman decides to carry the pregnancy to term. Staging of the cancer to see if it has already spread to other areas helps determine the type of treatment.
