Prospective analysis of prostate-specific markers in pelvic lymph nodes of patients with high-risk prostate cancer

AC Ferrari1,*, NN Stone2, JN Eyler1, M Gao1, J Mandeli3, P Unger4, RE Gallagher6 and R Stock5

1Division of Neoplastic Diseases, 2Department of Urology, 3Department of Biomethematical Sciences, 4Department of
Pathology, 5Department of Radiation Oncology, Mount Sinai Medical Center, One Gustave Levy Place, Box 1129, New
York, NY 10029, USA, 6Department of Oncology, Montefiore Medical Center and Albert Einstein Cancer Center, Bronx,
NY, USA, *Corresponding author

Background: Pathological evidence of pelvic lymph node involvement is obtained in 12%-20% of patients with localized
prostate cancer that exhibits high-risk features (defined on the basis of tumor size, serum prostate-specific antigen (PSA] level,
or Gleason score). The rate of systemic failure (i.e., relapse) in patients with this type of prostate cancer and of pathological
evidence of regional lymph node involvement is 55%-92% within 5 years of definitive local therapy. Since reverse
transcription-polymerase chain reaction (RT-PCR) methods are likely to be more sensitive than routine pathological
examination in detecting metastatic tumor cells, we compared the ability of the two approaches to detect prostate cells in the
pelvic lymph nodes of patients with localized, high-risk disease.

Methods: fifty-eight lymph node specimens isolated from 3 patients before definitive local therapy were examined. Expression
of PSA and prostate-specific membrane antigen (PSM) messenger RNAs in the specimens was assessed by means of nested
RT-PCR.

Results: Pathological examination identified tumor cells in the lymph nodes of four (12%) of the 33 patients, and PSA and/or
PSM expression was positive in specimens from 27 (82

5) of the patients (two-sided P<.0001). The four patients with positive pathologic findings also had positive RT-PCR results.
Among the 29 patients with no pathologic evidence of lymph node involvement, 23 (79%) tested positive by means of
RT-PCR. In these 23 patients, PSM expression was detected more frequently than PSA expression; however, in two patients,
only PSA expression was detected.

Conclusions: Expression of prostate-specific markers in the pelvic lymph nodes of patients with localized, high-risk prostate
cancer may indicate the presence of metastatic tumor cells. Such cells may be responsible for the high rate of systemic failure
seen in these patients. Additional studies are required to determine the prognostic relevance of four findings.

Journal of the National Cancer Institute, Volume 89, Issue 20: October 15, 1997.
Pages 1498-1504