Negative upper and lower resection margins for prostate cancer usually means primarily that the radical prostatectomy was relatively successful and that there are no cancer cells present at either its upper or lower margins.
Cancer resections usually need to ensure that the resected margins are negative, thus minimizing the probability of cancer cells growing back. Patients who have negative upper and lower margins of the prostate after radical prostatectomy are considered to have had a successful surgery and need to undergo regular check-ups after the surgery to avoid recurrence of the cancer.
Besides, whether the cancer recurs after radical prostatectomy usually depends on whether the cancer is high-risk, intermediate-risk or low-risk, and whether it is in the early stage, especially low-risk and early-stage patients generally have a smaller recurrence rate.