There are national guidelines for breast surgeons about waiting times for operations.
When an operation is to diagnose a breast cancer this should be carried out within two weeks of the decision to operate.
When the operation is to remove a known breast cancer it should be carried out within two weeks of the decision to operate. The maximum acceptable delay is one month. The only exceptions to this would be when there were planned delays, for example to give other treatments such as chemotherapy.
The guidelines also say that once it has been decided to offer surgical treatment patients should be offered a date for the operation rather than put on a waiting list.
These recommendations are based mainly on the fact that waiting for breast cancer surgery can be worrying and stressful, rather than on evidence that a delay of a few weeks will make the cancer any worse. Waiting times for surgery can vary from hospital to hospital. It is important that your sister discusses her concerns with her specialist.
Reference
Guidelines for the management of symptomatic breast disease. The Association of Breast Surgery. EJSO (2005) 31. S1-S21

