Value of prostate cancer screening

Low serum testosterone and a younger age predict for a poor outcome in metastatic prostate cancer

Carcinoma of the prostate gland is one of the most common malignancies in males. This study was undertaken to determine which factors predict the course and outcome of patients treated with first line hormonal manipulation. A total of 144 patients with Stage D2 prostate cancer who received androgen deprivation therapy were studied. Pretreatment parameters analyzed were age, performance status, analgesia usage, concurrent disease, histologic differentiation, hemoglobin, leukocyte and platelet count, serum creatinine, alkaline phosphatase, lactate dehydrogenase, prostate specific antigen, total and prostatic acid phosphatase, serum testosterone, follicle stimulating and luteinizing hormone levels, number of metastatic sites and bone scan grade. Only initial serum testosterone (> 10 nmol/l) had a positive impact on response (p = 0.0304), whereas age older than 60 years had a positive impact on time to progression (16 vs. 11 months, p = 0.0414). Both serum testosterone (26 vs. 20 months, p = 0.003), and age (28 vs. 17 months, p = 0.036) had a significant influence on overall survival. Low testosterone, indicating androgen independence, and a younger age, seem to result in a more aggressive disease and a poorer prognosis in advanced prostate cancer.

The fall in incidence of prostate carcinoma. On the down side of a prostate specific antigen induced peak in incidence--data from the Utah Cancer Registry

BACKGROUND

In the 1980s, prostate specific antigen (PSA) came into wide use as a prostate carcinoma screening and detection method in the United States. Following the introduction of PSA, the age-adjusted incidence of prostate carcinoma reported by the Surveillance, Epidemiology, and End Results (SEER) program in the United States rose rapidly (from 84.4/100,000 in 1984 to 163/100,000 in 1991). When an increase in incidence is observed following the introduction of a screening method, a subsequent decrease in incidence may be expected as prevalent cases are removed from the population (a cull effect). Incidence rates may also fall due to factors such as decreased intensity of screening. The Utah Cancer Registry data were examined for a decrease in prostate cancer incidence.

METHODS

We tracked age-adjusted prostate carcinoma incidence trends from the population-based Utah Cancer Registry and compared them with rates from the SEER national registry.

RESULTS

A rapid and highly correlated rise in prostate carcinoma incidence has been observed in both SEER and Utah incidence rates between 1988 and 1991, the last year for which SEER data are available. In 1992, Utah incidence rates peaked at 236.2 per 100,000. In 1993 and 1994, Utah incidence rates fell to 195.0, and an estimated 164.0 per 100,000, respectively.

CONCLUSIONS

Population-based data from the Utah Cancer Registry indicates that the incidence of prostate carcinoma is decreasing rapidly after a similarly rapid increase.

Can aggressive prostatic carcinomas be identified and can their natural history be altered by treatment?

The factors that determine tumor aggressiveness are multifactorial: age, stage, and grade. Even a well differentiated tumor in a young patient may be aggressive someday because of genetic drift and tumor heterogeneity. In a recent review of 826 favorably selected cases managed with conservative therapy, metastatic disease had developed in 19% with grade I tumors, 42% with grade II, and 74% with grade III at 10 years. Recognizing that < 20% of men present with grade I disease, most prostate cancers are a threat to life in men who are going to live longer than 10 years. On the other hand, some tumors at presentation are too far advanced to cure. To improve the accuracy of preoperative staging in identifying these cases, we have developed nomograms based upon clinical stage, grade, and serum prostate-specific antigen (PSA). Traditionally, patients with high-grade tumors (Gleason 8-10) were never considered candidates for radical prostatectomy because of their poor expectancy for long-term survival. However, with improvements in the staging of prostate cancer and with a reduction in the morbidity of radical prostatectomy, a subset of these patients are potential candidates for curative therapy. We have recently studied the clinical outcome of 72 men with Gleason scores of 8-10 on needle biopsies who presented with clinically localized disease (9 T1c, 22 T2a, 17 T2b, 13 T2c, and 11 T3a). Of the 63 men who underwent radical prostatectomy, 46 (68%) had negative lymph nodes; nine did not undergo surgery because of positive lymph nodes identified from frozen section. The actuarial likelihood of an undetectable serum PSA at 5 years was 43% for men with negative lymph nodes and 45% for men with organ-confined disease. Thus, with proper evaluation, some men with even the most aggressive tumors can be cured by surgery if their pelvic lymph nodes are negative.

PSA and clinical problems relating to prostate cancer

The PSA is the most important tumoral marker for prostate cancer. Not all Authors agree that it plays an important role in screening and diagnosis, classification and prognosis; they agree, instead, about its monitoring the response to therapy. Two personal experiences are presented: in one the PSA values are compared with the prostatic biopsies in 100 patients with suspect rectal exploration; in the other the PSA value, taken at the moment of diagnosis, is compared with the result of the radionuclide bone scan in 43 patients with prostate cancer.