Women with small early breast cancers may have a better chance of survival if they have lumpectomy plus radiation therapy than mastectomy, according to a new analysis due to be published early online in the journal Cancer this week.

Although they did not determine why women who had mastectomy had a higher risk of dying, Shelley Hwang of the Duke Cancer Institute in the US, and colleagues, suggest their findings provide confidence in the effectiveness of breast-conserving treatments even in women who have aggressive, early breast cancers.

The news is timely because over the last 10 years, there has been a growing tendency for women diagnosed with breast cancer to opt for mastectomy, even if they have small early cancers.

The researchers suggest there are certain groups of women, such as those who are younger and more well off, who have come to believe their survival chances following breast cancer would be better with a mastectomy than a lumpectomy.

Hwang says in a statement:

“The findings in this study should reassure women that among all age groups and tumor types, lumpectomy continues to be an excellent choice for women with small early breast cancers.”

For their study, Hwang and colleagues examined data on over 112,000 cases of stage I and stage II breast cancer diagnosed in women in California between 1990 and 2004 who had either a mastectomy or lumpectomy plus radiation therapy, and were followed up to 2009.

They searched among different age groups and types of breast cancer for patterns between type of treatment and survival rates.

The results showed that in the first three years following surgery, women who had a mastectomy were more likely to die from heart disease and other diseases compared with women who had a lumpectomy.

Hwang suggests perhaps the women who had lumpectomy were in better health.

Over the whole study period, women who had lumpectomy plus radiation were more likely to survive breast cancer than women who had mastectomy.

In fact for any age or cancer type, lumpectomy plus radiation was linked to a better survival rate than mastectomy.

The biggest effect was in women over 50 with hormone-sensitive breat cancers. Their risk of dying from breast cancer during the follow-up was 14% lower than similar women with similar cancers who had mastectomy.

The researchers did not investigate the reasons behind these results, and the question why women appear to fare better with lumpectomy and radiation as opposed to mastectomy, which more seem to be going for, remains to be answered.

One concern women have when choosing a treatment option, is whether their cancer will recur, and the perception that this is less likely following mastectomy, may influence their choice.

Last week, researchers in Canada, published findings of a study showing how breast cancer recurrence may be predictable with a simple blood test.

Written by Catharine Paddock PhD