Updated

Women newly diagnosed with earlier-stage breast cancer can take a few weeks to prepare for surgery without raising the odds that their tumor will progress, a new study suggests.

There are a number of reasons that a woman's surgery for breast cancer might be delayed. She might want to get a second opinion, for example, or her doctors may need to make sure any other medical conditions are under control and she's healthy enough for surgery.

But whether those short-term delays can allow a woman's tumor to progress has not been clear.

In the new study, researchers found that of 818 women treated at their center, there was no evidence that a "modest" delay before surgery gave breast tumors time to grow and spread.

"Clearly, rapid treatment is desirable," said senior researcher Dr. Funda Meric-Bernstam of M.D. Anderson Cancer Center in Houston.

"However," she told Reuters Health, "taking a few weeks to coordinate care is safe. It's very unlikely there will be tumor progression."

The findings, published in the Annals of Surgery, offer women reassurance that they do not need to rush into surgery before they are ready.

Meric-Bernstam said that patients often have questions about the safety of delaying surgery for a short time.

"Some women want to get a second opinion, but feel that they don't have time," she said.

In other cases, a woman may want to undergo breast reconstruction at the same time as the cancer surgery. But because that can delay treatment for a short time -- since different surgeons' schedules have to be coordinated -- some women forgo immediate reconstructive surgery.

There are caveats from the current study.

All of the women were having surgery for cancer that was confined to the breast and had not yet spread to nearby lymph nodes. So the findings apply only to that group of breast cancer patients.

The study was also done at a single medical center -- though, Meric-Bernstam said, it's likely that the findings can be generalized to women treated elsewhere.

Patients in the study typically had surgery three weeks after imaging tests to diagnose their cancer -- though the wait time ranged from as little as one day to about four months.

Women who underwent breast reconstruction waited somewhat longer -- typically one month, versus 19 days among other patients. And women having a total mastectomy waited longer (typically 26 days) than those only having the cancer removed (17 days).

When the researchers weighed other factors -- like the woman's age and how aggressive the cancer appeared -- they found no evidence that a longer wait for surgery raised the odds of tumor growth.

Meric-Bernstam stressed that she is not suggesting women put off surgery for any substantial amount of time.

But, she said, a "modest" delay that allows their doctors to plan and coordinate their care -- and women to prepare themselves for surgery -- could potentially improve their outcomes.

Still, it's not clear whether surgical delays affect women's ultimate breast cancer survival, either negatively or positively. Larger, longer-term studies are needed, Meric-Bernstam said.