Prostate cancer patients have good survival outcomes with pelvic lymph node dissection

June 1, 2011

Men with clinically localized prostate cancer who undergo radical retropubic prostatectomy with bilateral pelvic lymph node dissection show a higher than expected incidence of lymph node metastases, but men with nodal involvement have excellent 10-year clinical recurrence-free survival.

Key Points

Washington-Men with clinically localized prostate cancer who undergo radical retropubic prostatectomy with bilateral pelvic lymph node dissection (PLND) show a higher than expected incidence of lymph node (LN) metastases, but men with nodal involvement have excellent 10-year clinical recurrence-free survival, results of a retrospective study found.

Data for the study were extracted from review of a prospectively maintained University of Southern California, Los Angeles prostate cancer database. After excluding men treated preoperatively with radiation or androgen deprivation or whose risk group was indefinable, 2,487 men were identified who underwent radical prostatectomy and bilateral PLND between July 1988 and June 2008. Minimum postoperative follow-up was 1 year, and the median was 7.2 years.

The median number of LNs removed per patient was 16. LN involvement was found on pathologic examination in 150 men (6.0%), and the majority of these men had low-volume nodal disease with just one (53.3%, 80/150) or two (26.7%, 40/150) positive LNs. About two-thirds of the men with LN+ disease went on to receive adjuvant therapy after surgery.

Co-author Sia Daneshmand, MD, associate professor of clinical urology and director of urologic oncology at USC/Norris Cancer Center, told Urology Times, "These results are consistent with findings from European studies reporting LN-positive rates in the range of 6% to 10% among men with clinically organ-confined disease, and together the data suggest that the Partin tables underestimate the extent of LN involvement in this subgroup of prostate cancer patients.

"Growth of robot-assisted radical prostatectomy has led to a shift away from performing PLND. However, considering our findings of a risk of LN involvement that is not insignificant and showing that lymphadenectomy can be curative, we recommend performing bilateral PLND in all men undergoing radical prostatectomy for prostate cancer, except perhaps for those in the lowest-risk group."

"Furthermore," Dr. Daneshmand added, "by providing definitive information about LN status, lymphadenectomy enables early institution of ADT, which has been shown in a randomized trial to significantly improve prognosis. If a patient's nodal status remains unknown because lymphadenectomy was omitted, that patient may be at a disadvantage if he subsequently develops a recurrence and ADT is started later."

In 2004, Dr. Daneshmand and colleagues reported a study investigating outcomes in a series of 235 patients with clinically localized prostate cancer found to have LN-positive disease after prostatectomy performed between 1972 and 1999 (J Urol 2004; 172:2252-5). In that cohort, the 10-year clinical recurrence-free survival rate was about 70% in patients with limited nodal involvement (one or two positive nodes) and 49% in those with five positive nodes. Other studies have shown similar or even higher rates of clinical recurrence-free survival at 10 years in men found to have LN metastasis at surgery. The present investigation was undertaken to examine the findings and outcomes in a more contemporary series of men with clinically localized cancer, said Dr. Daneshmand.

"Previous data showed lymphadenectomy can be therapeutic and that patients with limited disease can be cured by PLND," he said. "However, we wanted to update our knowledge by looking at a more relevant cohort of men diagnosed with prostate cancer in the PSA era and who specifically have clinically localized disease. This population represents the predominant group undergoing radical prostatectomy with minimally invasive techniques today, many of whom have PLND omitted based on a predicted low risk of nodal metastasis."