Last Updated: 2003-08-11 14:25:12 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Young women who give birth after being diagnosed with breast cancer appear to fare no worse, and possibly better, than their peers who do not have a child, according to a new report published in the August 11th online issue of Cancer.

In several studies, researchers have found no evidence that childbearing adversely affects breast cancer survival. Still, most of these studies have not assessed the risk of death, taking into account different factors that can influence breast cancer outcome, such as patient age and tumor characteristics.

To investigate, Dr. Beth A. Mueller, from Fred Hutchinson Cancer Research Center in Seattle, and colleagues conducted a study of 438 women who gave birth after a breast cancer diagnosis and 2775 similar patients who did not give birth after their diagnosis.

Women who gave birth at least 10 months after diagnosis were 46% less likely to die than were women who did not give birth, the researchers note. However, this may not represent a true beneficial effect of childbearing, but rather a "healthy mother" effect in which disease-free mothers are the ones most likely to become pregnant, they caution.

Overall, women who were pregnant when cancer was diagnosed had a death rate that was comparable to that of women who did not give birth. However, for certain subgroups, such as women 35 years of age or older and those with adverse disease characteristics, pregnancy at diagnosis was tied to increased mortality.

These findings, "particularly in light of a growing body of evidence from other studies using various methods," may give some reassurance to young women with breast cancer that childbearing is unlikely to increase their risk of death, the authors note.