M1 prostate cancer with a serum level of prostate‐specific antigen less than 10 ng/mL

Abstract

Background: M1 prostate cancer, which is invasive, is usually associated with a serum level of prostate-specific antigen (PSA) greater than 10 ng/mL, but cases are occurring where the serum PSA level is less than this. The present study investigated the clinical and pathologic characteristics of these cases of M1 prostate cancer. Methods: Between April 1989 and March 1998, 167 cases of M1 prostate cancer were diagnosed by transrectal needle biopsy and eight of these with a serum PSA level less than 10 ng/mL were investigated. The patients' ages ranged from 57 to 79 years (median, 73) and the serum PSA levels ranged from less than 4.0 to 9.8 ng/mL. In all cases except one, the distal metastasis was to bones only. All cases had received hormonal therapy as the initial therapy. Immunostaining of PSA, chromogranin A, neuron-specific enolase, carcinoembryonic antigen and vimentin were performed in five of the eight cases. Results: Four cases were poorly differentiated, two were undifferentiated, one was a mixture of poorly differentiated and undifferentiated and one case was moderately differentiated. Of the five cases in the immunohistochemical study, three cases with an undifferentiated carcinoma component showed negative staining reactions for PSA and all cases were positive for carcinoembryonic antigen. Four of the patients died of prostate cancer. In two of these four cases, hormonal therapy was ineffective, but systemic chemotherapy and irradiation therapy had been moderately effective. The overall 3-year survival rate was 33.3%. Conclusions:The cases of M1 prostate cancer with a serum PSA less than 10 ng/mL are almost always poorly differentiated or undifferentiated and have a poor prognosis compared with the usual M1 prostate cancer. Because hormonal therapy is ineffective in these cases, systemic chemotherapy and irradiation therapy should be chosen as the initial therapy.

Clinical features of patients who present with metastatic prostate carcinoma and serum prostate‐specific antigen (PSA) levels < 10 ng/mL

“…14 In reviewing 167 patients with M1 prostate carcinoma who presented over an 11-year period, only 8 patients with a serum PSA levels Ͻ 10 ng/mL were identified. 5 It has been proposed that an undifferentiated component correlates with nonresponsiveness to hormone therapy, 15 and other series have been comprised almost exclusively of poorly differentiated and undifferentiated tumors. 5 In 3 patients with metastatic prostate carcinoma who had serum PSA levels Ͻ 10 ng/mL, all tumors were of high Gleason grade, and the authors postulated that the tumors had lost the characteristics of the original prostate tissue itself, which affected PSA release into the blood stream.…”

“…5 It has been proposed that an undifferentiated component correlates with nonresponsiveness to hormone therapy, 15 and other series have been comprised almost exclusively of poorly differentiated and undifferentiated tumors. 5 In 3 patients with metastatic prostate carcinoma who had serum PSA levels Ͻ 10 ng/mL, all tumors were of high Gleason grade, and the authors postulated that the tumors had lost the characteristics of the original prostate tissue itself, which affected PSA release into the blood stream. 16 Other authors also have described the association between advanced prostate carcinoma stage with a low PSA level and poorly differentiated tumors.…”

“…12,19 Our response rate is similar to that seen in smaller case series of patients with PSA-negative tumors, in which responses to first-line hormone therapy were observed in two of four patients. 5 Nonetheless, the majority of patients did demonstrate a symptomatic response to androgen-deprivation therapy, and this remains the recommended initial treatment.…”

“…[5][6][7] To our knowledge, information is sparse concerning this group of tumors, although they have been associated with high tumor grade (Gleason score, 8 -10). 3,8 Based on anecdotal evidence, it is believed that overall survival is poorer in these patients who have low PSA levels compared with patients who have PSApositive metastatic prostate carcinoma.…”

“…3,8 Based on anecdotal evidence, it is believed that overall survival is poorer in these patients who have low PSA levels compared with patients who have PSApositive metastatic prostate carcinoma. 5 The pattern of metastatic disease is considered to be unlike the pattern observed in tumors with high PSA levels, with increased numbers of visceral and soft tissue metastases (up to 55% of patients) and a nontypical pattern of bone disease seen. 9 However, these latter data were obtained from patients with androgen independent, clinically progressive disease rather than patients who presented with treatment-naïve metastatic prostate carcinoma with low serum PSA levels.…”