14545 Background: The value of the extent of lymph node dissection at radical prostatectomy remains controversial. We report our experience with extended lymph node dissection in patients undergoing open radical prostatectomy. Methods: 201 consecutive patients with cT1c-cT3a prostate cancer who underwent open radical prostatectomy with an extended regional lymph node (LN) dissection of up to six packets (iliac, hypogastric, and obturator; right and left) by a single surgeon at The Methodist Hospital between July 2002 and April 2004 were studied. No patient was treated with adjuvant radiation or hormonal therapy before elevated PSA levels were observed. Ultrasensitive PSA (uPSA) using the 3rd generation Immulite assay (DPC) was performed periodically beginning at 6 weeks post operatively. A uPSA level ≥ 0.03 ng/mL and rising on at least one subsequent uPSA obtained at least six weeks later was classified as a biochemical recurrence (BCR). Results: The mean patient age was 59 years at the time of surgery (median, 59; range, 39 to 73 years). Median follow-up after surgery was 21 months (range 1–37 months). Gleason Score was ≤ 6, 7, and 8–10 in 37%, 53% and 10% of patients, respectively. Sixty-two patients had extra prostatic extension and 16 patients had seminal vesicle involvement. A total of 3125 pelvic lymph nodes were removed (per patient: mean, 15.64; median, 15; range 4–42). Of these 22 LN (0.71%) were positive in 11 (5.5%) patients. By specified region, 2/1775 (0.23%) of iliac nodes, 6/642 (0.93%) of hypogastric nodes and 9/708 (1.27%) of obturator nodes were positive. Of the 11 patients with positive LN, 3/11 (27.27%) had positive iliac nodes, 6/11 (54.54%) had positive hypogastric nodes, and 6/11 (54.54%) had positive obturator nodes. Using a very stringent definition of BCR in order to compensate for the relatively short follow-up period, the 2 year progression-free survival (PFS) for patients with at least one positive LN was 37.5%. Conclusions: Extended LN dissection may alter the biology of early nodal metastatic prostate cancer and lead to longterm PFS without additional therapy. A higher percentage of patients and nodes are positive in the hypogastric and obturator regions, supporting the rationale to include these with the iliac nodes when performing LN dissection. No significant financial relationships to disclose.