Morton K. Schwartz

Prostate-specific antigen as a measure of disease outcome in metastatic hormone-refractory prostate cancer.

PURPOSE To evaluate the prognostic significance of pretreatment parameters and posttherapy declines in prostate-specific antigen (PSA) in relation to the survival of patients with hormone-refractory prostate cancer. PATIENTS AND METHODS One hundred ten assessable patients treated on seven sequential protocols at Memorial Sloan-Kettering Cancer Center (MSKCC) for hormone-refractory prostate cancer were evaluated for 29 different pretherapy and posttherapy parameters, including a posttherapy decline in PSA of 50% and 80% from baseline. RESULTS In the univariate analysis, initial Karnofsky performance status (KPS) > or = 80% was associated with a favorable outcome (P = .005), while age, extent of disease on bone scan, and individual sites of metastatic disease were not significant. No difference in survival was observed between patients with measurable or assessable (bone only) disease. Initial hemoglobin (HGB; P = .0012), alkaline phosphatase (ALK; P = .0015), and lactate dehydrogenase (LDH; P = .0002) levels were significant discriminators, while the initial PSA was not. Using a landmark analysis, a significantly longer median survival rate was observed for patients with a > or = 50% decline in PSA (median not reached) versus patients with a less than 50% decline in PSA (median, 8.6 months; P = .0001). Multivariate analysis using the Cox proportional hazards model showed that a > or = 50% decline in PSA (P = .0004) and the natural log of LDH (P = .0001) were the two most significant variables predicting survival. The model was confirmed on an independent data set from the Norwegian Radium Hospital (NRH) in Oslo, Norway. CONCLUSION The results suggest that posttherapy PSA declines can be used as a surrogate end point to evaluate new agents in hormone-refractory prostate cancer. The criteria for response need prospective validation in phase III trials.

Serum folate, homocysteine and colorectal cancer risk in women: a nested case–control study

SummaryAccumulating evidence suggests that folate, which is plentiful in vegetables and fruits, may be protective against colorectal cancer. The authors have studied the relationship of baseline levels of serum folate and homocysteine to the subsequent risk of colorectal cancer in a nested case–control study including 105 cases and 523 matched controls from the New York University Women’s Health Study cohort. In univariate analyses, the cases had lower serum folate and higher serum homocysteine levels than controls. The difference was more significant for folate (P < 0.001) than for homocysteine (P = 0.04). After adjusting for potential confounders, the risk of colorectal cancer in the subjects in the highest quartile of serum folate was half that of those in the lowest quartile (odds ratio, OR = 0.52, 95% confidence interval, CI = 0.27–0.97, P-value for trend = 0.04). The OR for the highest quartile of homocysteine, relative to the lowest quartile, was 1.72 (95% CI = 0.83–3.65, P-value for trend = 0.09). In addition, the risk of colorectal cancer was almost twice as high in subjects with below-median serum folate and above-median total alcohol intake compared with those with above-median serum folate and below-median alcohol consumption (OR = 1.99, 95% CI = 0.92–4.29). The potentially protective effects of folate need to be confirmed in clinical trials.

Paclitaxel, Estramustine Phosphate, and Carboplatin in Patients With Advanced Prostate Cancer

PURPOSE To determine the safety and activity of weekly paclitaxel in combination with estramustine and carboplatin (TEC) in patients with advanced prostate cancer. PATIENTS AND METHODS In a dose-escalation study, patients with advanced prostate cancer were administered paclitaxel (weekly 1-hour infusions of 60 to 100 mg/m(2)), oral estramustine (10 mg/kg), and carboplatin (area under the curve, 6 mg/mL-min every 4 weeks). Paclitaxel levels were determined 0, 30, 60, 90, and 120 minutes and 18 hours after infusion, and a concentration-time curve was estimated. Once a safe dose was established, a multi-institutional phase II trial was conducted in patients with progressive androgen-independent disease. RESULTS Fifty-six patients with progressive androgen-independent disease were treated for a median of four cycles. The dose of paclitaxel was escalated from 60 to 100 mg/m(2) without the occurrence of DLT. Posttherapy decreases in serum prostate-specific antigen levels of 50%, 80%, and 90% were seen in 67%, 48%, and 39% (95% confidence interval, 55% to 79%, 35% to 61%, 26% to 52%) of the patients, respectively. Of the 33 patients with measurable disease, two (6%) had a complete response and 13 (39%) had a partial response. The overall median time to progression was 21 weeks, and the median survival time for all patients was 19.9 months. Major grade 3 or 4 adverse effects were thromboembolic disease (in 25% of patients), hyperglycemia (in 38%), and hypophosphatemia (in 42%). Significant leukopenia, thrombocytopenia, and peripheral neuropathy were not observed. CONCLUSION TEC has significant antitumor activity and is well tolerated in patients with progressive androgen-independent prostate cancer.

Flow cytometry of breast carcinoma: I. Relation of DNA ploidy level to histology and estrogen receptor.

Flow cytometry studies of the DNA distribution of tumor cells from 92 human breast cancers showed measurable aneuploidy (hyperploidy) in 85 cases (92%). The DNA ploidy values were unimodal in each case, but there was a bimodal distribution for the entire series. One group of tumors had a diploid or near diploid DNA distribution and a second group had ploidy levels from triploid to tetraploid or higher. The tumors with lower DNA ploidy (at or near diploid) tended to be histologically low grade, cytologically more orderly and estrogen‐binding positive; those with higher DNA ploidy were more likely to be higher grade, more anaplastic, and estrogen‐binding negative.

Complexed prostate specific antigen provides significant enhancement of specificity compared with total prostate specific antigen for detecting prostate cancer.

PURPOSE Determining serum total prostate specific antigen (PSA) has proved to be a valuable diagnostic aid for detecting prostatic carcinoma, although the lack of specificity has limited its usefulness. Studies indicate that the use of percent free PSA would improve specificity while maintaining sensitivity. Since complexed PSA represents the major proportion of measurable PSA in serum, we determined whether it represents a single test alternative to the use of percent free PSA for the early detection of prostate cancer. MATERIALS AND METHODS Archival serum was obtained from 385 men with no evidence of malignancy on biopsy and 272 with biopsy confirmed prostate cancer. We determined the concentration and proportion of total, complexed and free PSA. RESULTS Receiver operating characteristics analysis using total PSA results from all samples (range 0.32 to 117 ng./ml.) indicated that the areas under the curve for complexed PSA alone as well as the free-to-total and complexed-to-total PSA ratios were similar and significantly greater than those for total PSA alone. Within the range of 85% to 95% sensitivity receiver operating characteristics analysis revealed that the specificity of complexed PSA was higher than that of total PSA and equivalent to that of the free-to-total PSA ratio. We noted a similar improvement in specificity in the 4 to 10 ng./ml. total PSA range. Using published cutoff values for complexed, total and percent free PSA when total PSA was in the 4 to 10 ng./ml. range the sensitivity and specificity of complexed and percent free PSA were similar. Within the 4 to 10 ng./ml. total PSA range the population of patients with no evidence of malignancy and complexed PSA below the upper limit was different with respect to total PSA from that with no evidence of malignancy and free PSA greater than 25%. CONCLUSIONS The measurement of complexed PSA represents an alternative to the use of percent free PSA, although the patient populations identified by the 2 tests are different.

Estrogen receptor protein of breast cancer as a predictor of recurrence

Estrogen receptor protein (ERP) determinations of primary cancers of 1034 patients with primary breast cancer were done. ERP‐positive patients tended to have a lower recurrence rate and had significantly improved survival. This difference was most apparent in patients with four or more axillary nodes involved. ERP‐positive patients who recurred had a better survival. ERP did not influence response to adjuvant chemotherapy, nor did the presence of progesterone receptor or femtomole level of ERP affect recurrence.

CEA (carcinoembryonic antigen): Its role as a marker in the management of cancer

SummaryA Consensus Development Conference was held at the National Institutes of Health from September 29-October 1, 1980, to address issues concerning the role of carcinoembryonic antigen (CEA) as a marker in the management of cancer. The panel met following formal presentations and discussions to assess the issues based on the evidence presented. These issues included: Should CEA be used in cancer screening? Is CEA helpful in cancer diagnosis? What does CEA tell about the extent and outcome of cancer? Is CEA helpful in monitoring cancer treatment? This paper constitutes the panels findings.

Comparison of methods of evaluating nephrotoxicity of cis‐platinum

The urinary excretion of leucine aminopeptidase (LAP), N‐acetyl‐β‐glucosaminidase (NAG), and β2‐microglobulin was measured in 12 cancer patients receiving cis‐platinum to evaluate the sensitivity of these indices for renal tubular damage. NAG and LAP excretion rose markedly in all patients, and β2‐microglobutin rose in 11. Seven of the 9 patients who had received cis‐platinum 6 wk before the study had prestudy dose elevations of one or more of these indices. We conclude that these urinary proteins are sensitive indicators of proximal renal tubular injury and may provide greater sensitivity for comparison of the nephrotoxic potential of future platinum analogs or for assessing the efficacy of regimens designed to protect the kidney from platinum nephrotoxicity than other measurements. The persistence of high excretion values for these indices 6 wk after a dose demonstrates the persistent renal injury by cis‐platinum.

Prospective evaluation of hydrocortisone and suramin in patients with androgen-independent prostate cancer.

PURPOSE To assess efficacy of intermittent infusion of suramin in patients with androgen-independent prostate cancer who have had disease progression on hydrocortisone. PATIENTS AND METHODS Chemotherapy-naive patients with progressive androgen-independent prostate cancer were given hydrocortisone 40 mg/d and monitored for treatment effect. At the time of disease progression, suramin was administered on a pharmacokinetically derived, 2-week dosing schedule. RESULTS Thirty patients with a median Karnofsky performance status (KPS) of 90% were treated with hydrocortisone. No responses were seen in 12 patients with measurable disease or 29 patients with abnormal bone scans. Thirty patients had an increasing prostate-specific antigen (PSA) level before treatment and six (20%) had a more than 50% decline in PSA from the baseline value for a median of 16 weeks (range, 12 to 52+). Twenty-eight patients had disease progression after a median of 7 weeks (range, 3 to 23), and two patients have continued to receive hydrocortisone for 44 and 52 weeks. Twenty-eight patients received hydrocortisone and suramin, with median suramin concentrations of 97 to 170 micrograms/mL for 4 weeks. No responses in measurable disease and no improvements in bone scans were seen. Five patients (18%) showed a more than 50% decline in PSA levels from baseline, of whom three had previously responded to hydrocortisone. Only two of 24 patients who did not show a posttherapy decline in PSA levels after hydrocortisone had a reduction in PSA levels with the addition of suramin. Toxicity profiles were acceptable with each agent, although a higher proportion of subjects showed hematologic, cardiac, and neurologic events when suramin was added. CONCLUSION Suramin has limited efficacy in patients with androgen-independent prostate cancer who have had disease progression after hydrocortisone.

Iron intake, body iron stores and colorectal cancer risk in women: a nested case-control study

Accumulated evidence suggests that increased body iron stores may increase the risk of colorectal cancer, possibly via catalyzing oxidation reactions. We examined the relationship between iron status and colorectal cancer in a case‐control study nested within the New York University Womens Health Study cohort. For 105 incident cases of colorectal cancer with an average follow‐up of 4.7 years and 523 individually matched controls, baseline levels of serum iron, ferritin, total iron binding capacity (TIBC) and transferrin saturation were determined as indicators of body iron stores, and total iron intake was assessed based on their diet and supplement intake. Overall, there were no associations between the risk of colorectal cancer and any of these indices except for serum ferritin, which showed a significant inverse association. When analyzed by subsite, there was an increasing trend in risk of cancer of the proximal colon with increasing total iron intake (p‐value for trend = 0.04). In addition, a significantly increased risk of colorectal cancer associated with higher total iron intake [odds ratio (OR) = 2.50; 95% confidence interval (CI): 1.06–5.87] was observed among subjects with higher intake of total fat. Our results do not support a role of increased body iron stores in the development of colorectal cancer, but suggest that luminal exposure to excessive iron may possibly increase the risk in combination with a high fat diet. Int. J. Cancer 80:693–698, 1999.