Survival rates are better for women with breast cancer who get their surgery and chemo more quickly, as reported in JAMA Oncology:

Time to Surgery and Breast Cancer Survival in the United States 

 Delayed Initiation of Adjuvant Chemotherapy Among Patients With Breast Cancer

Timeliness in Breast Cancer Treatment—The Sooner, the Better

Approximately 100,000 women were studied. The first study looked at how the timing between the diagnosis and surgery impacts survival.  Most women with breast cancer have some form of surgery – either a lumpectomy or a full mastectomy.

The second study assessed how women with invasive breast cancer fared depending on how long they waited after surgery to start chemotherapy. Many women receive chemo after surgery to remove any remaining abnormal cells and reduce the risk of recurrence.

They found that women with early breast cancer’s had their survival odds decline by almost 10% for every 30-day delay in surgery beyond the first 30 days after diagnosis.

“We are not talking about providing care in days, but a woman should not have to wait months,” said Dr. Eric Winer, a researcher at Harvard University and director of the breast program at Dana-Farber Cancer Institute in Boston.

“We need to reinforce for doctors that delays could be a problem for some patients and that, in any case, timely care could not be bad,” Winer, senior author of an editorial accompanying the studies in JAMA Oncology, said by email.

You can read more on this here.