Surgery for breast cancer after initial diagnosis taking longer. A study at Fox Chase Cancer Center in Philadelphia of women between 1992 and 2005 showed that the average time between diagnosis and surgery increased from 21 days to 32 days. The time from the first cancer related visit to biopsy also increased. This increased treatment delay was greatest for black and Hispanic women and people who live in large cities. Although it is unknown how much of a difference this delay is making, the trend is problematic.