Squamous cell carcinoma antigen in genitourinary tumors

We have evaluated the serum levels of squamous cell carcinoma (SCC) antigen in patients with adenocarcinoma of the kidney, adenocarcinoma of the prostate, germ cell tumors of the testis, transitional cell carcinoma of the bladder, and SCC of the penis, urethra, and bladder. Serum SCC antigen levels were elevated in 5 of 11 patients (45%) with metastatic SCC of the penis, and in the 3 patients for whom serial determinations were made, the serum levels correlated correctly with the progression of disease or response to treatment. The antigen was elevated in 1 of 3 patients with SCC of the urethra, and 1 apparent false-positive value was observed in a patient with adenocarcinoma of the prostate. Otherwise, no SCC antigen elevations were noted among 10 patients with metastatic adenocarcinoma of the prostate, 8 with metastatic adenocarcinoma of the kidney, 11 with metastatic transitional cell carcinoma of the bladder, 8 with metastatic nonseminomatous germ cell tumors of the testis, and 2 patients with metastatic SCC of the bladder

Comparison of assay methods for detection of circulating tumor cells in metastatic breast cancer: AdnaGen AdnaTest BreastCancer Select/Detect™ versus Veridex CellSearch™ system

The detection of CTCs prior to and during therapy is an independent and strong prognostic marker, and it is predictive of poor treatment outcome. A major challenge is that different technologies are available for isolation and characterization of CTCs in peripheral blood (PB). We compare the CellSearch system and AdnaTest BreastCancer Select/Detect, to evaluate the extent that these assays differ in their ability to detect CTCs in the PB of MBC patients. CTCs in 7.5 ml of PB were isolated and enumerated using the CellSearch, before new treatment. Two cutoff values of ≥2 and ≥5 CTCs/7.5 ml were used. AdnaTest requires 5 ml of PB to detect gene transcripts of tumor markers (GA733-2, MUC-1, and HER2) by RT-PCR. AdnaTest was scored positive if ≥1 of the transcript PCR products for the 3 markers were detected at a concentration ≥0.15 ng/μl. A total of 55 MBC patients were enrolled. 26 (47%) patients were positive for CTCs by the CellSearch (≥2 cutoff), while 20 (36%) were positive (≥5 cutoff). AdnaTest was positive in 29 (53%) with the individual markers being positive in 18% (GA733-2), 44% (MUC-1), and 35% (HER2). Overall positive agreement was 73% for CTC≥2 and 69% for CTC≥5. These preliminary data suggest that the AdnaTest has equivalent sensitivity to that of the CellSearch system in detecting 2 or more CTCs. While there is concordance between these 2 methods, the AdnaTest complements the CellSearch system by improving the overall CTC detection rate and permitting the assessment of genomic markers in CTCs.

Technical validation of an autoantibody test for lung cancer

Background: Publications on autoantibodies to tumour-associated antigens (TAAs) have failed to show either calibration or reproducibility data. The validation of a panel of six TAAs to which autoantibodies have been described is reported here.

Materials and methods: Three separate groups of patients with newly diagnosed lung cancer were identified, along with control individuals, and their samples used to validate an enzyme-linked immunosorbant assay. Precision, linearity, assay reproducibility and antigen batch reproducibility were all assessed.

Results: For between-replicate error, samples with higher signals gave coefficients of variation (CVs) in the range 7%–15%. CVs for between-plate variation were only 1%–2% higher. For between-run error, CVs were in the range 15%–28%. In linearity studies, the slope was close to 1.0 and correlation coefficient values were generally >0.8. The sensitivity and specificity of individual batches of antigen varied slightly between groups of patients; however, the sensitivity and specificity of the panel of antigens as a whole remained constant. The validity of the calibration system was demonstrated.

Conclusions: A calibrated six-panel assay of TAAs has been validated for identifying nearly 40% of primary lung cancers via a peripheral blood test. Levels of reproducibility, precision and linearity would be acceptable for an assay used in a regulated clinical setting.

Circulating tumor cells and FDG-PET/CT: biological and functional methods for therapeutic monitoring in metastatic breast cancer

Abstract #6052

Introduction: The combination of Computed Tomography (CT) and [18F] Fluorodeoxyglucose - Positron Emission Tomography (FDG-PET) scanning technologies provides a more complete picture of disease activity than CT alone. Circulating tumor cell (CTC) levels were shown to be more predictive than standard imaging (CT) when used to monitor disease progression in women with metastatic breast cancer (MBC). We performed a retrospective study to compare the ability of combined FDG-PET/CT to CTC to predict clinical outcomes in patients treated for MBC.
 Methods: One hundred and two MBC patients with either measurable or evaluable disease starting a new line of therapy had CTC counts and FDG-PET/CT scans done at baseline (BL) and at mid-therapy. CTC: 7.5mL of blood collected in CellSave tubes at both time points was assayed for CTC using the FDA approved CellSearch® System. Patients were categorized as having a favorable (<5CTC) or unfavorable (≥5CTC) outcome. Imaging: non-contrast-enhanced CT images were acquired first, then FDG-PET/CT scans were performed after administering a mean dose of 555 MBq FDG (range 444-740 MBq) to fasting patients. CT, PET, and co-registered CT-PET images were reviewed independently by 2 radiologists. The highest recorded FDG uptake was semi-quantitatively analyzed and maximum standardized uptake value (SUV) calculated with response = SUV of <50% in target lesions and no response = SUV of >50%. Changes in CTC and SUV at mid-therapy were compared to progression free survival (PFS) and overall survival (OS).
 Results: CTC: 50% (51/102) patients had ≥5 CTC at baseline (BL). At mid-therapy (median 2.5 months from BL), 21/102 progressed (≥5CTC) with a median PFS of 2.8 months vs. 7.8 months for those with no progression (<5CTC) (p<0.0001). OS was 10.0 months for patients with ≥5CTC at mid-therapy vs. 29.6 months for those with <5CTC (p<0.0001). PET/CT: 48% (49/102) patients showed no response at mid-therapy with median OS = 17.4 months vs. 29.6 months for those responding (p=0.0020). Overall, there was approximately 75% concordance in predicting outcomes between imaging and CTC assay changes [Table 1]. The majority of patients with discordant results had more advanced aggressive disease, i.e., >2nd line chemotherapy and triple-negative disease.
 
 Conclusion: ≥5 CTC and/or no response at FDG-PET/CT at mid-therapy accurately predicted significantly shorter OS.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6052.

Circulating tumor cells (CTCs) in metastatic breast cancer: Biological value beyond tumor burden

615

Background: The detection of circulating tumor cells (CTCs) can predict progression-free (PFS) and overall survival (OS) in patients with metastatic breast cancer (MBC). We evaluated the prognostic significance of baseline CTCs in relation to standard measures of tumor burden. Furthermore, we assessed if the prognostic value of CTCs was related to any particular molecular phenotype. Patients and Methods: One hundred twenty-three consecutive MBC patients (pts) evaluated prospectively between 12/2000 and 5/2005 were included in this analysis. CTCs from 7.5 mL of whole blood were isolated and enumerated using CellSearch system. Prognostic value was determined by analyzing the following factors, baseline level of CTCs (negative: <5 CTCs/7.5 mL; positive: ≥ 5 CTCs/7.5 mL), age (50 yrs<vs. >/=50 yrs), hormonal receptor (HR), Her-2/neu status, metastatic site (visceral vs. non-visceral), Swenerton score, CA27.29 levels, and previous chemotherapy for MBC (none vs. pre-treated), Results: Median age was 52 years (range 24–88) and the median follow-up was 7.7 months (range 0–53.4 months). The median OS for the alive pts was 17.5 months. Fifty-two pts (42%) had positive CTCs and abnormal CA27.29 was detected in 80 pts (66%). The median OS for patients with negative vs. positive CTCs were 28.3 months (range 1.28 - 31.24) and 12.8 months (range 1.71 to 36.83) respectively (p=0.0001). In the multivariable model, HR status, CTCs, and CA27.29 level were the only factors significantly related to OS. CTCs demonstrated the strongest predictor for OS and were associated with 2.53 times the risk of death (p = 0.003). The prognostic value of CTCs was independent of line of treatment, site of recurrence and phenotype of the disease. Conclusions: CTCs demonstrated prognostic value independent of standard measures of tumor burden and phenotypic characteristics of the disease. CTCs are an important marker of tumor biology in metastatic breast cancer.

No significant financial relationships to disclose.

CAN COMPLEXED PROSTATE SPECIFIC ANTIGEN AND PROSTATIC VOLUME ENHANCE PROSTATE CANCER DETECTION IN MEN WITH TOTAL PROSTATE SPECIFIC ANTIGEN BETWEEN 2.5 AND 4.0 NG./ML

PURPOSE

We assessed whether complexed prostate specific antigen (PSA) and complexed PSA referenced variables would enhance prostate cancer detection in men with serum total PSA between 2.5 and 4.0 ng./ml.

MATERIALS AND METHODS

Transition zone and total prostate gland volumes were determined in 151 men who underwent prostate biopsy using an 11 core biopsy strategy. In addition to measuring the Bayer section sign complexed PSA assay, we also calculated 2 computed complexed PSA values (Hybritech parallel total PSA--Hybritech free PSA and Bayer total PSA--Hybritech free PSA). We calculated 8 volume referenced variables using total and complexed PSA, and 2 computed complexed PSA values by dividing each value by the total prostate and transition zone volumes.

RESULTS

Of the 151 patients 37 (24.5%) had cancer. In 10 of the 37 men with cancer (27%) a positive core was present in only 1 or more of the 5 alternate regions not sampled by conventional sextant biopsies. At 92% sensitivity a cutoff value of 2.3 ng./ml. for complexed and 31% for free-to-total PSA provided 42% and 11% specificity, respectively (p <0.001). In the 116 men with a total prostate volume of 30 cc or greater at 92% sensitivity the specificity of complexed PSA density (55%) and complexed PSA adjusted for transition zone volume (52%) were better than that of complexed (40%) and free-to-total (11%) PSA. In the 35 men with a total prostate volume of less than 30 cc at 92% sensitivity the specificity of complexed PSA (50%), complexed PSA density (55%) and complexed PSA adjusted for transition zone volume (55%) were significantly better than that of free-to-total PSA (8%, p <0.001). The area under the curve of complexed PSA was almost identical to that of the 2 computed complexed PSA calculations.

CONCLUSIONS

A substantial proportion of men with total PSA values between 2.5 and 4.0 ng./ml. had prostate cancer. Complexed and computed complexed PSA were more specific than the free-to-total PSA ratio when total PSA was between 2.5 and 4.0 ng./ml. A 2.3 ng./ml. threshold for complexed and computed complexed PSA appears to stratify prostate biopsy results in men with total PSA between 2.5 and 4.0 ng./ml. The computed complexed PSA calculation appears to be equivalent to the complexed PSA serum assay for detecting cancer. Volume referenced complexed PSA performed better than complexed PSA in men with a total prostate volume of 30 cc or greater compared to men with a total prostate volume of less than 30 cc.

The effect of 13-cis-retinoic acid chemoprevention on human serum retinol levels

This study of the effect of 13-cis-retinoic acid on serum levels of retinol was a laboratory correlate of a clinical chemoprevention trial in asymptomatic chronic smokers. All study participants had squamous metaplasia of the bronchial epithelium and received 6 months' treatment of either 13-cis-retinoic acid (1 mg/kg/day) or placebo. Baseline serum retinol levels were compared with levels taken immediately post-treatment. The placebo group (N = 38) had little change, whereas the 13-cis-retinoic acid group, (N = 35) experienced a decline in retinol levels (p = 0.06). Within the 13-cis-retinoic acid group, women's (N = 13) mean serum retinol levels dropped significantly, from 531 +/- 191 ng/ml (baseline) to 436 +/- 115 ng/ml (post-treatment) (p = 0.03); men's (N = 22) levels virtually did not change (p = 0.43). Therefore, the borderline-significant overall decline in the 13-cis-retinoic acid group was due entirely to the decline among women subjects. The etiology of this effect is unknown. Our results suggest that chronic 13-cis-retinoic acid administration may lead to a clinically significant reduction in serum retinol levels in females. This finding may have implications for currently ongoing chemoprevention trials that administer 13-cis-retinoic acid for 3 years.

Lactate dehydrogenase isoenzyme 1 is the most important LD isoenzyme in patients with testicular germ cell tumor

We examined the clinical utility of serum lactate dehydrogenase (LD) isoenzyme catalytic concentrations in 58 patients with testicular germ cell tumors (TGCT) (13 with seminoma and 45 with non-seminomatous tumors). Twenty-one patients with no evidence of disease (NED) all had serum LD isoenzyme 1 catalytic concentrations (LD-1) and LD-1/LD fractions below the upper limit of the reference values (ULR). LD-1 and the LD-1/LD fraction discriminated significantly between evidence of disease (ED) and NED (p = 0.00009 and p = 0.028, respectively, Mann Whitney U-test). Twenty of the 37 patients with ED had raised values of LD-1. The 17 patients with an LD-1 < 1.0 x ULR had a better survival than the 10 patients with LD-1 between 1.0 and 2.9 x ULR, the 7 with LD-1 between 3.0 and 5.9 x ULR, and the 3 patients with LD-1 > 6.0 x ULR (p = 0.006, log-rank test, chi2 test for trend)). Twenty-three patients with an LD-1/LD fraction < or = 0.25 had a better survival than the 14 with an LD-1/LD fraction > 0.25 (p = 0.013). Nineteen patients with LD-5 < 105 U/L and the 15 with LD-5 > 105 U/L had a similar rate of survival (p = 0.85). Our findings add to the evidence showing LD-1 in preference to LD as a serum tumor marker of TGCT.

N-(4-hydroxyphenyl)retinamide in the chemoprevention of squamous metaplasia and dysplasia of the bronchial epithelium

Lung cancer remains the number one cause of cancer-related deaths in the United States. To reduce the mortality associated with this disease, individuals at risk must be identified prior to the development of lung cancer, and effective prevention strategies must be developed. One such strategy is to use retinoids like N-(4-hydroxyphenyl)retinamide (4-HPR), which has been found to possess chemopreventive activities in preclinical studies. In this study, 139 smokers were registered and 82 were randomized onto a double-blinded, placebo-controlled chemoprevention trial of 4-HPR administered p.o. (200 mg once daily). Of these, 70 participants were eligible for response evaluation. Biopsies were obtained at six predetermined sites in the bronchial tree from participants before and at the completion of 6 months of treatment. 4-HPR treatment had no measurable effect on histopathology (squamous metaplasia and dysplasia) in the bronchial epithelium of current smokers. 4-HPR was detected (104.5+/-64.0 ng/ml, mean +/- SD) in the serum of participants, supporting its potential bioavailability. Serum retinol levels decreased markedly (44% of placebo-treated patients) as a consequence of 4-HPR treatment. Notably, the mRNA level of retinoic acid receptor beta, which is typically increased by retinoid treatment, did not change in the bronchial epithelium of 4-HPR-treated participants. Clonal populations of bronchial epithelial cells were detected by analysis of loss of heterozygosity at putative tumor suppressor loci on chromosomes 3p, 9p, and 17p, and these changes were not altered by 4-HPR treatment. In conclusion, at this dose and schedule, 4-HPR was not effective in reversing squamous metaplasia, dysplasia, or genetic and phenotypic abnormalities in the bronchial epithelium of smokers.

Relative contributions of technetium Tc 99m sestamibi scintigraphy, intraoperative gamma probe detection, and the rapid parathyroid hormone assay to the surgical management of hyperparathyroidism

HYPOTHESIS

Technetium Tc 99m sestamibi scintigraphy, intraoperative gamma probe detection, and the rapid parathyroid hormone assay have been used to permit a directed operation in patients with hyperparathyroidism. We hypothesized that the coordinated use of these techniques might be particularly useful in patients who require a second operation for hyperparathyroidism.

DESIGN

Retrospective analysis was performed to determine the specific contribution of these technologies to the surgical management of patients with hyperparathyroidism who underwent evaluation by at least 2 of these techniques between April 1996 and October 1999.

SETTING

Patients were evaluated and treated by an endocrine tumor surgery group within a tertiary care referral center.

PATIENTS

Coordinated application of 99mTc-sestamibi scintigraphy, intraoperative gamma probe detection, and/or the rapid parathyroid hormone assay was performed in 32 patients.

RESULTS

Twenty-eight of 32 patients had primary hyperparathyroidism, 3 had multiple endocrine neoplasia type 1, and 1 had secondary hyperparathyroidism. The surgical procedure was an initial cervical exploration in 19 and a second operative procedure in 13. Parathyroidectomy was successful in all patients. A directed anatomic operation was performed in 24 patients, including 11 patients who underwent second operative procedures and 9 patients who underwent minimally invasive procedures under local anesthesia. A directed operation was facilitated by sestamibi scan in 22 of 24 patients, intraoperative gamma probe detection in 5 of 23 patients, and the rapid parathyroid hormone assay in 15 of 15 patients.

CONCLUSIONS

Coordinated application of 99mTc-sestamibi scintigraphy, intraoperative gamma probe detection, and the rapid parathyroid hormone assay allows for successful directed reoperative parathyroidectomy; a minimally invasive procedure may be performed in selected patients.

Calcium-induced activation of a mutant G-protein-coupled receptor causes in vitro transformation of NIH/3T3 cells

The calcium-sensing receptor (CaR) is a G-protein-coupled receptor that is widely expressed, has tissue-specific functions, and regulates cell growth. Activating mutations of this receptor cause autosomal dominant hypocalcemia, a syndrome characterized by hypocalcemia and hypercalciuria. The identification of a family with an activating mutation of the CaR (Thr151Met) in which hypocalcemia cosegregates with several unusual neoplasms led us to examine the transforming effects of this mutant receptor. Transfection of NIH/3T3 cells with the mutant but not the normal receptor supported colony formation in soft agar at subphysiologic calcium concentrations. The mutant CaR causes a calcium-dependent activation of the extracellular signal-regulated protein kinase (ERK) 1/2 and Jun-N-terminal kinase/stress-activated (JNK/ SAPK) pathways, but not P38 MAP kinase. These findings contribute to a growing body of information suggesting that this receptor plays a role in the regulation of cellular proliferation, and that aberrant activation of the mutant receptor in this family may play a role in the unusual neoplastic manifestations.

Urinary nuclear matrix protein 22 (NMP22): a diagnostic adjunct to urine cytologic examination for the detection of recurrent transitional-cell carcinoma of the bladder

This study compares urine nuclear matrix protein 22 (NMP22) immunoassay and conventional urine cytologic examination for detecting recurrent transitional-cell carcinoma (TCC) of the urinary bladder. One hundred twenty-eight urine specimens from 107 patients with a history of TCC of the urinary bladder were studied. NMP22 immunoassay and conventional cytologic examination were performed on each specimen. The NMP22 and cytology results were then compared with the results of subsequent cystoscopies/surgical biopsies performed over a 6-mo follow-up period. The sensitivity of urine cytologic study for predicting recurrent TCC was 60%, while the sensitivity of NMP22 assay was 47%. When both NMP22 assay results and the cytologic interpretation were positive for TCC, the positive predictive value of the combined tests was 74%. When both tests showed negative results, the negative predictive power was 81%. Our findings suggest that urine NMP22 assay may represent a useful diagnostic adjunct to conventional urine cytologic examination for the detection of recurrent TCC of the urinary bladder.

Bayer Immuno 1 PSA Assay: an automated, ultrasensitive method to quantitate total PSA in serum

The Bayer Immuno 1 PSA Assay measures total PSA in human serum and demonstrates excellent performance with an interassay CV < or = 3.4% and a biological detection limit of 0.03 microgram/L. No significant interference from common hormonal and chemotherapeutic drugs, kallikrein, prostatic acid phosphatase, and trypsin, or elevated levels of total bilirubin, hemoglobin, triglycerides, and IgG was observed. The 95th percentile values for healthy individuals increased with age from 3.0 micrograms/L for males 50-59 years and 3.3 micrograms/L for males 60-69 years, to 4.6 micrograms/L for males > or = 70 years. Clinical studies with retrospective samples demonstrated correspondence between serial measurements of PSA and clinical outcome for 98% of 159 prostate cancer patients. Clinical sensitivity for patients with clinical evidence of disease, untreated at the time of specimen draw, increased with increasing stage from 77.5-100%. Specificity of 60-70% for BPH and other benign urogenital diseases was consistent with previous findings. Bayer Immuno 1 PSA Assay values for 2131 specimens from healthy subjects and patients with prostate cancer, BPH, and other malignant and nonmalignant diseases correlated well with the Abbott IMx PSA Assay over the range 0.0-6,238 micrograms/L (Y = 1.10 x + 0.02). The Bayer Immuno 1 PSA Assay provides automated ultrasensitive, precise, and equimolar measurement of total PSA in human serum.

Multicenter evaluation of the Bayer Immuno I CA 15-3 assay

We conducted a multicenter evaluation of the analytical and clinical features of the automated Bayer Immuno 1 CA 15-3 assay and compared assay performance to two manual tests. Results of the 10-day imprecision study of the Bayer Immuno 1 assay pooled across four evaluation sites and three lots of reagent produced total CV < or = 4%. Lot-to-lot reproducibility for 26 different lots of reagents and calibrators manufactured over a 2-year period was demonstrated (CV, 1.1%). Results for the Bayer Immuno 1 assay correlated well with the Biomira TRUQUANT BR 27.29 and Centocor CA 15-3 RIAs (r > or = 0.94). The upper limit of the reference interval for the Bayer Immuno 1 assay was 35.9 kilounits/L (35.9 units/mL); values were similar for all methods. Longitudinal monitoring of healthy women yielded assay values with an average CV of 11% and 21% for the Bayer Immuno 1 and Biomira assays, respectively. The Bayer Immuno 1 assay demonstrated the analytical features, intermethod correlation, and long-term performance characteristics that are essential for longitudinal monitoring of breast cancer patients.

Modulation of cellular proliferation and production of prostate-specific antigen and matrix adhesion molecules in human prostate carcinoma cells by polypeptide growth factors: comparative analyses of MDA PCa2a with established cell lines

The cellular responses of a newly established and early-passage human prostate adenocarcinoma cell line, MDA PCa2a, to transforming growth factor (TGF) beta1, epidermal growth factor (EGF), and TGFalpha were characterized in terms of proliferation, production of prostate-specific antigen (PSA), fibronectin (FN) and laminin (LM). The responses of the MDA PCa2a cells were compared with those of the well-established human prostate carcinoma cell lines LNCap, PC3, and DU145. The MDA PCa2a cells were more responsive to the growth-inhibitory effect of TGFbeta1 than the established cell lines. The androgen-responsive cell lines (MDA PCa2a and LNCap) were relatively responsive to the growth-stimulatory effect of EGF and TGFalpha whereas the androgen-independent lines (PC3 and DU145) were not. Only the androgen-responsive cells produced PSA, which was further upregulated by treatment with growth factors. The androgen-independent cells did not produce PSA, and growth factors had no effect on PSA production. However, all cell lines produced abundant amounts of FN and LM, and the levels of production of these molecules were subject to modulation by growth factors. It is concluded that each growth factor elicits diverse and distinct responses in prostate carcinoma cells, which may reflect the involvement of diverse post-receptor signal pathways.

Evaluation of NMP22 in the detection of transitional cell carcinoma of the bladder

PURPOSE

Urinary nuclear matrix protein (NMP22) was evaluated for detection of new and recurrent bladder tumors in patients with a history of transitional cell carcinoma. Our objective was to determine sensitivity and specificity of this marker for tumors of various stages and grades, as well as its use as an adjunct to or substitute for urinary cytology.

MATERIALS AND METHODS

A total of 231 patients with a history of transitional cell carcinoma provided 288 voided urine samples before cystoscopic examination at 1 of 3 institutions (53 patients were reevaluated at least once). Urine samples were assayed for NMP22 using the NMP22 Test Kit. Select patients underwent biopsy with appropriate additional therapy. Voided urinary cytology was obtained in 200 cases. End points for determination of the absence and presence of tumor were negative cystoscopy and positive biopsy, respectively. A receiver operating characteristics curve was constructed to determine the optimal NMP22 threshold for detection of transitional cell carcinoma. For positive biopsies NMP22 values were also correlated with tumor stage and grade. Comparison to cytology was limited to patients with complete data.

RESULTS

There were 208 negative cystoscopies (158 with cytology) and 66 positive cystoscopies with biopsy (42 with cytology). Of the cases 14 were eliminated from statistical analysis due to incomplete data. Receiver operating characteristics curve interpretation determined that 6.4 units per ml. was an optimal reference value for detection of transitional cell carcinoma in this patient group. Sensitivity and specificity for all pathological groupings was 68 and 80%, respectively. When compared to cytology the sensitivities of NMP22 and cytology were 67 versus 31 or 40% (depending on the definition of positive cytology).

CONCLUSIONS

NMP22 values represented significant improvement over urinary cytology for detection of transitional cell carcinoma. The sensitivity of NMP22 for detection of transitional cell carcinoma in bladder cancer patients was as much as twice that of cytology when a reference value of 6.4 units per ml. was used. NMP22 analysis was less costly than cytology and operator independent. While NMP22 has previously been shown to be a strong predictor of recurrence after tumor resection, it is an effective and sensitive screening test for detecting tumors in patients with transitional cell carcinoma.

Evaluation of prostAsure index in the detection of prostate cancer: a preliminary report

OBJECTIVES

Although prostate-specific antigen (PSA) has revolutionized the detection of prostate cancer, it has definite limitations with respect to its clinical sensitivity and specificity. Because a substantial number (20% to 40%) of men undergoing radical prostatectomy have a PSA level of 4.0 ng/mL or less, any new test offering diagnostic improvement must perform well in patients whose PSA level is less than or equal to 4.0 ng/mL, as well as in patients whose PSA is greater than 4.0 ng/mL. The performances of two tests, the ProstAsure index and the percent free PSA test, were evaluated in detecting cancer.

METHODS

We retrospectively analyzed serum samples from 225 men who were grouped into three categories: 94 men who had a normal digital rectal examination and a serum PSA level of 4.0 ng/mL or less, 77 men who were clinically suspected of having benign prostatic hyperplasia (BPH) with a serum PSA level of 4.0 ng/mL or less, and 54 men with localized prostate cancer. The PSA assays were performed using the Hybritech and Tosoh assays and the ProstAsure index was determined by Global Health Net, Savannah, Ga. Receiver operator characteristic (ROC) curves were constructed to evaluate the performance of these two tests, and the areas under the curve were compared for significance.

RESULTS

The sensitivity and specificity of detecting prostate cancer using ProstAsure were 93% and 81%, respectively. Using a cutoff value of 15%, the sensitivity and specificity of detecting cancer for percent free PSA were 80% and 74%, respectively (sensitivity increased to 93% and specificity to 59% for free PSA at 19%). In men with a total serum PSA level of 4.0 ng/mL or less, ProstAsure had a lower false-positive rate compared to free PSA level at 19% for men with or without clinical BPH as well as for men without clinical BPH using a 15% free PSA threshold. ProstAsure left fewer cancers undetected (7%) compared to free PSA at the 15% cutoff (20%).

CONCLUSIONS

In this study of selected men, ROC curve analysis shows a statistically significant advantage in performance (P = 0.0023) for the ProstAsure index compared to free PSA in detecting prostate cancer.

The induction of benign epithelial neoplasms of the ovaries of guinea pigs by testosterone stimulation: a potential animal model

We studied the effects of different hormones on the epithelial cells of the ovaries of 11 guinea pigs. Three received testosterone, two received estrone, three megestrol, and three chorionic gonadotropin. Three control guinea pigs received sterile water. Benign epithelial cysts larger than 1.5 mm were found in six guinea pigs, three who received testosterone, one who received megestrol, and two who received chorionic gonadotropin. In one of the three guinea pigs who received testosterone, 2.5-cm bilateral cysts were grossly identified. Papillary excrescences were found on the ovarian surface in four guinea pigs, three who received testosterone and one who received megestrol. The proliferating epithelial cells also formed benign glands in the ovarian stroma in two guinea pigs who received testosterone, the most exuberant epithelial proliferations, including large bilateral cystadenomas, papillary excrescence that formed a small papillary neoplasm, and glands in the ovarian stroma that formed adenomatous areas, were seen in the guinea pig who received an intermediate dose of testosterone for the longest time. By radioimmunoassay, the serum level of testosterone was 22 ng/dL in one of the controls and 10,000, 12,000, and 15,000 ng/dL in the three guinea pigs who received testosterone. In the guinea pig with the most exuberant epithelial proliferation, the level of testosterone in the uterus was similar to that in the serum (13,860 ng/mg), but in the wall of the ovarian epithelial cyst, it was three times higher than it was in the serum (44,000 ng/mg). Our study shows that testosterone stimulates the growth of epithelial cells in the ovaries of guinea pigs, resulting in benign cysts, small adenomas in the ovarian parenchyma, and papillomas on the ovarian surface. The study also shows that guinea pigs can be used as an animal model for epithelial tumors of the human ovary.

A clinical trial to evaluate the effect of vitamin C supplementation on in vitro mutagen sensitivity. The University of Texas M. D. Anderson Clinical Community Oncology Program Network

Mutagen sensitivity, as measured by an in vitro assay, has been described as a risk factor for the development of several tobacco-related epithelial cancers. In vitro studies have indicated that sensitivity to the clastogenic effects of bleomycin on chromosomes was reduced with the introduction of ascorbic acid in a dose-dependent relationship. We report the results of a randomized clinical trial to determine whether increasing levels of oral ascorbic acid could reduce the levels of mutagen sensitivity. For this study, we recruited 228 healthy smokers from 21 centers around the country through the Clinical Community Oncology Program. Each individual was randomly assigned to one of four daily regimens: placebo, 1 g of ascorbic acid, 2 g of ascorbic acid, or 4 g of ascorbic acid. Treatments were administered for 16 weeks. Assessment of mutagen sensitivity was made at baseline and at weeks 4, 16, and 20 (4 weeks after cessation of treatment). Serum ascorbic acid levels were measured at baseline and at weeks 4 and 16. Demographic and risk factor data were collected at baseline and at each-measurement point. Analyses measured the differences of mutagen sensitivity levels across the four treatment arms, as well as investigating the correlation between serum ascorbic acid level and mutagen sensitivity levels in individuals. We did not find a dose-response relationship between ascorbic acid intake and mutagen sensitivity. Additionally, we did not find an association between serum ascorbic acid levels and mutagen sensitivity.

Use of Truquant BR radioimmunoassay for early detection of breast cancer recurrence in patients with stage II and stage III disease

PURPOSE

The Truquant BR radioimmunoassay (RIA) (Biomira Diagnostics Inc, Rexdale, Canada) uses the monoclonal antibody B27.29 to quantitate the MUC-1 gene product (CA 27.29 antigen) in serum. We evaluated CA 27.29 antigen in a controlled, prospective clinical trial for its ability to predict relapse in stage II and stage III breast cancer patients.

PATIENTS AND METHODS

Over a 2-year period, 166 patients who had completed therapy for stage II (80.1%) or III (19.9%) breast cancer and were clinically free of disease were serially tested for CA 27.29 antigen levels. The study was double-masked and cancer recurrence was documented based on clinical findings. Patients with two consecutive CA 27.29 antigen test results above the upper limit of normal were considered positive.

RESULTS

The Truquant BR RIA had a sensitivity of 57.7%, specificity of 97.9%, positive predictive value of 83.3%, and negative predictive value of 92.6%. The recurrence rate was 15.7%. A Cox regression analysis showed that the only variable to correlate with recurrent disease was the CA 27.29 antigen test result. Patients with a positive test result had increased odds of having a recurrence (odds ratio, 6.8; P < .00001). The test was effective in predicting recurrence in patients with both distant and locoregional disease. In a subgroup of patients with bone pain, CA 27.29 antigen level was found to identify reliably patients who would subsequently develop recurrent disease.

CONCLUSION

These data demonstrate that the Truquant BR RIA can be used as an aid to predict recurrent breast cancer in patients with stage II and III disease.

Underestimation of monoclonal proteins by agarose serum protein electrophoresis

The effect of serum dilution on monoclonal protein quantitation by serum protein electrophoresis (SPE) on the agarose gel Paragon system was investigated in 388 serum samples from 106 patients with Ig G monoclonal gammopathy. It was found that the pre-electrophoretic 1:5 serum dilution recommended by the manufacturer was adequate for some but not all sera, especially those with the highest M-protein concentrations. As a result of the inadequate dilution, 232 (60 percent) of the 388 samples had M-protein concentrations that were significantly underestimated and the corresponding albumin concentrations overestimated. By Paragon SPE, the mean albumin concentration in these 232 sera was 41.8 (SD 6.7) g/L. After further dilution of these sera, the mean albumin concentration was 36.7 (SD 6.8) g/L and was, in each case, always less than that in the corresponding 1:5 diluted serum. By the bromcresol green (BCG) dye-binding method, the albumin concentration was 34.9 (SD 4.3) g/L. Similarly, the M-protein concentration for 1:5 diluted sera was 51.9 (SD 12.9) g/L vs. 59.1 (SD 16.1) g/L for the further diluted sera, with the M-protein concentration in each further diluted sample always exceeding that in the corresponding 1:5 diluted serum. Underestimation of the M-protein concentration limits its clinical utilization in evaluating the patient's response to therapy and for early detection of disease progression. A recommendation was made of a 1:10 dilution of sera that contain total protein from 91 g/L to 114 g/L and a 1:20 dilution of sera in which the protein content is in the range of 115 g/L to 152 g/L to insure accurate estimation of protein fractions by Paragon SPE.

Phase I trial of alpha-tocopherol effects on 13-cis-retinoic acid toxicity

BACKGROUND

Retinoids are under intensive study for the treatment and prevention of cancer. Substantial dose-related toxicities of retinoids are a major obstacle to this work. In a recent retrospective analysis of combined 13-cis-retinoic acid (13cRA) and alpha-tocopherol (AT) in myelodysplasia, 13cRA toxicity was reduced significantly and 13cRA activity was enhanced. These results suggested the need for prospective testing of this new combination. This trial tested the hypotheses that At can reduce toxicity of high-dose 13cRA and does not interfere with 13cRA absorption/activity as reflected by reduced 13cRA serum levels.

PATIENTS AND METHODS

This was a phase I trial design in which patients received fixed-dose 13cRA (100 mg/m2/d) plus escalating-dose AT (beginning at 800 IU/d, increased 400 IU/d each month until 2000 IU/d). We collected toxicity data every four weeks from self-report forms, clinical examinations and laboratory studies. AT effects on 13cRA toxicity were determined by comparing maximum toxicity at lowest AT dose with that at highest AT dose. We also measured serum levels of both agents every four weeks.

RESULTS

Of the 45 patients registered, 36 had cancer (active or prior history), 9 had premalignant lesions. Thirty-nine patients could be evaluated for initial-course toxicity; 31 for final course toxicity. Median time on treatment (all patients) was four months (range, 1-9 months); a total of 223 month-long courses of treatment were given. Eighteen percent of patients (7/39) developed grade 3 or 4 toxicity in the initial course. The rates of increase and decrease in 13cRA toxicity associated with increasing AT doses were similar: 36% decreased (11/31), 32% increased (10/31) (P = 0.84). At did not reduce 13cRA serum levels. After initial increases of mean AT plasma levels (17.9 micrograms/ ml at baseline to 45.4 micrograms/ml after first four-week course), subsequent AT plasma increases (< 2-fold) did not keep pace with increased AT doses (2-3-fold). No major activity occurred in the 21 patients with active refractory cancer. The complete response rate in patients with premalignant head-and-neck or lung lesions was 77.8% (7/9), which included two patients previously refractory to 13cRA alone.

CONCLUSION

Although escalating doses of AT did not reduce 13cRA toxicity, the rate of initial-course (including 800 IU/d of AT) high-grade toxicity was substantially lower than that typical of high-dose 13cRA-alone and similar to that typical of low-dose 13cRA-alone. Indeed, a trial of 13cRA-alone followed by 13cRA plus AT may have detected a significant toxicity difference. We did not design such a trial out of ethical concern for known side effects of high-dose 13cRA. The increase in AT serum levels was not proportional with increasing doses of AT, which may explain the lack of a dose-response effect of AT on 13cRA toxicity. Previous trials have established that 13cRA has an approximate 10% complete response rate in oral premalignancy. Our small trial's 77.8% complete response rate in premalignant lesions suggests that AT may enhance 13cRA clinical activity. Future trials of 13cRA plus AT are needed to define this combinations toxicity profile, clinical activity and pharmacokinetics.

Bivariate RNA and DNA content analysis in breast carcinoma: biological significance of RNA content

Flow cytometric studies of mammary carcinoma have been limited to DNA content analysis. Simultaneous analysis of DNA and RNA has been applied to hematological and certain solid neoplasms and has been shown to provide valuable information in the clinical assessment of these tumors. To determine whether measuring RNA content during flow cytometric analysis provides additional information in the clinical assessment of breast carcinoma, dual-parameter analysis of DNA and RNA content on freshly disaggregated breast carcinoma specimens was performed. RNA content, divided along the mean (</=1.6 and >1.6), correlated with tumor grade, histological type, hormonal status, and patient survival. DNA aneuploidy was noted in 247 (69.2%) neoplasms and correlated significantly with tumor grade and stage but not with clinical outcome. The proliferative fraction, defined as S + G2-M and dichotomized along the mean value (</=10% and >10%), correlated significantly with tumor grade, size, hormonal status, lymph node involvement, and survival. Cox's proportional hazard analysis revealed that RNA content, proliferative fraction, and tumor stage are independent prognostic indicators. Our results indicate that measurement of cellular RNA content provides additional biological information that may be useful in the clinical assessment of breast carcinoma.

Risk classification for large cell lymphoma using lactate dehydrogenase, beta-2 microglobulin, and thymidine kinase

We have previously proposed a staging system for large cell lymphoma using the two serum markers beta-2-microglobulin (B2M) and lactate dehydrogenase (LDH). We recently tested this model in a different cohort of patients with large cell lymphoma and also examined the possible contribution of thymidine kinase (TK), a previously reported serologic prognostic factor. Using an inclusion criteria in the multivariate analysis for both forward and backward selection of p < 0.15, only LDH, B2M, and TK were significant independent prognostic factors for both time to treatment failure (TTF) and survival. Inclusion of TK in the serologic model resulted in three significantly different risk groups for both TTF and survival. Corresponding endpoints at three years were: 1) good risk (no markers elevated, n = 43): 78%, 91%; 2) intermediate risk (1 or 2 markers elevated, n = 47): 41%, 36%; 3) poor risk (3 markers elevated, n = 11): 0%, 0%. This analysis extends the observation of the independent prognostic significance of B2M and LDH. The addition of TK permits a more precise estimate of risk, contributing to the utility of a serological staging system for large cell lymphoma.

Serum levels of transforming growth factor alpha in gastrointestinal cancer patients

Transforming growth factor alpha (TGF alpha), a polypeptide growth-stimulating factor, has been implicated to play a role in the progression of gastrointestinal (GI) cancer. It has been suggested that TGF alpha expression in tumors or TGF alpha in the biological fluids of cancer patients may have tumor marker value. The serum levels of TGF alpha in GI cancer patients have not been reported. In this study, the serum TGF alpha levels of 100 GI cancer patients, as well as 74 healthy individuals, were determined by a TGF alpha-specific RIA kit. All of the cancer patient sera and 67% of the normal sera had detectable levels of TGF alpha. The TGF alpha concentrations in GI cancer patients ranged from 119 to 760 pg/ml, with a mean value of 269 +/- 102 pg/ml. Fifty normal individuals had detectable levels of TGF alpha, and their levels ranged from 120 to 207 pg/ml, with a mean value of 147 +/- 18 pg/ml. Differences in serum TGF alpha concentration between cancer patients and healthy individuals were found to be statistically significant, as evaluated by Mann-Whitney and Student's t tests. Serum TGF alpha levels were found to be significantly elevated in all disease stages of gastric, pancreas, colon, and rectal cancers, and only in the late stages of esophageal cancer. Serum carcinoembryonic antigen levels were significantly elevated only in the late stages of these diseases. The potential of serum TGF alpha as a tumor marker for GI malignancy, therefore, warrants further investigation.

Elevated serum levels of transforming growth factor-alpha in breast cancer patients

Previous studies suggest that transforming growth factor-alpha (TGF alpha) may have the potential of a tumor marker. Since the levels of serum TGF alpha in cancer patients and healthy individuals have not been reported, we determined the serum TGF alpha levels of 83 breast cancer patients and 74 healthy individuals by using a TGF alpha radioimmunoassay kit. All of the cancer patients' sera were positive for TGF alpha; their TGF alpha concentrations ranged from 210 to 740 pg/ml, with a mean of 353 +/- 98 pg/ml. Sixty-seven percent (50 cases) of normal sera were positive for TGF alpha; the levels ranged from 120 to 207 pg/ml, with a mean of 144 +/- 17 pg/ml. The difference in serum TGF alpha levels between cancer patients of different disease stages and healthy individuals was found to be statistically significant by Student t-test and the Mann-Whitney test. No correlation was found between serum carcinoembryonic antigen and TGF alpha levels. The potential of serum immunoreactive TGF alpha as a marker for breast cancer warrants further investigation.

Randomized placebo-controlled trial of isotretinoin in chemoprevention of bronchial squamous metaplasia

PURPOSE

Retinoids have proven chemopreventive efficacy in both preclinical and clinical studies. This trial was designed to confirm the finding of an earlier uncontrolled trial that the synthetic retinoid etretinate had major activity in reversing squamous metaplasia found in the bronchial epithelium of chronic smokers.

PATIENTS AND METHODS

We prospectively evaluated 152 smokers with bronchoscopy and obtained biopsies from six sites. Subjects with dysplasia and/or a metaplasia index of greater than 15% were randomly assigned to receive either 1 mg/kg isotretinoin or placebo daily for 6 months. Of 86 subjects randomized (41 isotretinoin, 45 placebo), 69 were reevaluated at the completion of treatment.

RESULTS

In the group as a whole, the metaplasia index decreased over time from a mean +/- SE of 35.8% +/- 2.7% at baseline to 28.1% +/- 3.3% at the completion of treatment (P = .01) by repeated measures analysis of variance [ANOVA]); a reduction in the metaplasia index (> 8%) was noted in both isotretinoin and placebo groups (19 of 35 [54.3%] and 20 of 34 [58.8%], respectively). Complete reversal of squamous metaplasia was noted in nine subjects from each group. However, the magnitudes of the mean metaplasia index changes did not differ significantly in the two treatment groups. In both groups, smoking cessation resulted in significant declines in the extent of squamous metaplasia, whereas no significant change in metaplasia index was found among those who continued to smoke.

CONCLUSION

Squamous metaplasia was frequently observed in bronchial biopsy samples from chronic smokers. From this study, we conclude that isotretinoin has no effect on squamous metaplasia, a potential intermediate end point of bronchial carcinogenesis. Although determining the exact role of isotretinoin in lung cancer prevention requires further study, the finding that there was a significant decrease in squamous metaplasia in the placebo group emphasizes the critical importance of a placebo-controlled study design in chemoprevention trials using intermediate end points.

Nonspecific cross-reacting antigen 50/90 is elevated in patients with breast, lung, and colon cancer

A total of 22 genes have been identified in the carcinoembryonic antigen (CEA) gene family. The protein products of this family are highly homologous and include CEA, biliary glycoprotein, nonspecific cross-reacting antigen 50/90 (NCA 50/90), NCA 95, and pregnancy-specific beta-glycoprotein. We used a monoclonal antibody with high affinity to develop a specific enzyme-linked immunosorbent assay (ELISA) method for NCA 50/90 in serum and plasma. Our calibrators were based on affinity-purified recombinant protein from a baculovirus expression system. No significant reactivity with purified CEA, recombinant NCA 95, or recombinant biliary glycoprotein was found by Western blot analysis or in the ELISA method. Only 1 of 15 sera from pregnant women (chorionic gonadotropin > 1000 ng/ml) was positive in the NCA 50/90 ELISA, suggesting that this method does not detect pregnancy-specific glycoprotein. A cutoff value of 18 ng/ml was established based on the 95% value of serum and plasma from 147 healthy volunteers. Only 3 of 31 serum and plasma samples from patients with clinically inactive breast cancer were elevated above the cutoff value, but 44% of 136 samples from patients with clinically active breast cancer were positive. NCA 50/90 measurements were elevated in 7 of 25 patients with active breast cancer whose CEA and CA 15-3 values were below cutoff, and NCA 50/90 values do not correlate with CEA in breast cancer. In addition, we found sensitivities of 70, 39, and 42% for lung cancer, colon cancer, and leukemia, respectively. The sensitivity for non-small cell lung cancer was 85%, however, compared to 50% for small cell lung cancer. Serum from leukemia patients showed an overall sensitivity of 43%, but 71% (10 of 14) sera from patients with chronic myelogenous leukemia were positive compared to, for example, chronic lymphocytic leukemia where 0 of 7 sera had NCA 50/90 values above the cutoff. These studies suggest that NCA 50/90 may have clinical utility in the management of patients with a variety of cancers.

Phase I trial of murine monoclonal antibody 14G2a administered by prolonged intravenous infusion in patients with neuroectodermal tumors

PURPOSE

The purpose of this phase I trial was to determine the toxicity and maximum-tolerated dose (MTD) of murine monoclonal antibody (Mab) 14G2a (anti-GD2) in cancer patients.

PATIENTS AND METHODS

Following tracer doses of iodine-131-labeled 14G2a to determine tumor uptake, 18 patients with refractory melanoma, neuroblastoma, or osteosarcoma received unlabeled 14G2a at total concentrations of 50, 100, and 200 mg/m2 administered as daily 24-hour infusions for 5 days.

RESULTS

The overall sensitivity of external immunoscintigraphy was 64 of 74 known metastases (86%). Toxicity from prolonged infusion of 14G2a consisted of severe generalized pain, hyponatremia, fever, rash, paresthesias, weakness, and chronic refractory postural hypotension (two patients). Toxicity was less severe in pediatric patients. The MTD of Mab was 100 mg/m2. Sixteen of 18 patients developed human antimouse antibodies (HAMA) to 14G2a. Terminal-phase half-life (T1/2) of unlabeled Mab was 6.6 +/- 1.8 hours for patients receiving 50 mg/m2 and 39.5 +/- 13.3 hours at the 100-mg/m2 level. Tumor biopsies from six melanoma patients were positive for GD2 antigen, but only two of six had trace amounts of 14G2a present. Three mixed responses (two melanoma, one osteosarcoma) and two partial responses (PRs; neuroblastoma) were observed.

CONCLUSION

Mab 14G2a has modest antitumor activity at the expense of significant toxicity. Dose-limiting neurologic sequelae may significantly limit phase II studies other than in pediatric patients with neuroblastoma.

Serum tumor markers for patient monitoring: a case-oriented approach illustrated with carcinoembryonic antigen

The effectiveness of patient monitoring with serum tumor markers is improved when the patient's pretreatment baseline is established, regular serial testing is performed, and a clinically significant change of the marker is determined on the basis of objective criteria. Attention must be directed to (a) ensuring long-term assay precision, (b) timing specimen collection to avoid misinterpretation of paradoxical increases (induced by chemotherapy, surgery, or radiation), (c) noting changes in the production or clearance mechanisms of the marker, and (d) recognizing the variability of site-response in patients who have multiple locations of metastatic disease. Clinical decisions to alter therapy should not be based only on tumor marker measurements. In the absence of other clinical data, a tumor marker abnormality should be confirmed with serial samples collected at a time interval dictated by the half-life of the marker. Serial tumor marker testing can improve cancer patient care, especially when effective salvage therapies are available.

Serum tumor markers for patient monitoring: a case-oriented approach illustrated with carcinoembryonic antigen

The effectiveness of patient monitoring with serum tumor markers is improved when the patient's pretreatment baseline is established, regular serial testing is performed, and a clinically significant change of the marker is determined on the basis of objective criteria. Attention must be directed to (a) ensuring long-term assay precision, (b) timing specimen collection to avoid misinterpretation of paradoxical increases (induced by chemotherapy, surgery, or radiation), (c) noting changes in the production or clearance mechanisms of the marker, and (d) recognizing the variability of site-response in patients who have multiple locations of metastatic disease. Clinical decisions to alter therapy should not be based only on tumor marker measurements. In the absence of other clinical data, a tumor marker abnormality should be confirmed with serial samples collected at a time interval dictated by the half-life of the marker. Serial tumor marker testing can improve cancer patient care, especially when effective salvage therapies are available.

Analytical performance goals for measuring prostate-specific antigen

We have assessed the feasibility of using fixed-limit criteria based on medical relevance and biological variation for evaluating the analytical performance of the prostate-specific antigen (PSA) test. The estimated within-subject variation of serum PSA is on the order of 10-20% at clinical decision points. The calculated performance goals of 5-10% CV are attainable with current immunoassay technology and agree with precision goals based on clinical experience and the current clinical use of the test. However, new clinical applications of PSA may require a degree of analytical performance that current methods may not be able to provide. The PSA model demonstrates the need for biologically based fixed-limit criteria for all tumor-marker tests.

Analytical performance goals for measuring prostate-specific antigen

We have assessed the feasibility of using fixed-limit criteria based on medical relevance and biological variation for evaluating the analytical performance of the prostate-specific antigen (PSA) test. The estimated within-subject variation of serum PSA is on the order of 10-20% at clinical decision points. The calculated performance goals of 5-10% CV are attainable with current immunoassay technology and agree with precision goals based on clinical experience and the current clinical use of the test. However, new clinical applications of PSA may require a degree of analytical performance that current methods may not be able to provide. The PSA model demonstrates the need for biologically based fixed-limit criteria for all tumor-marker tests.

Sequentially administered ethinyl estradiol and medroxyprogesterone acetate in the treatment of refractory epithelial ovarian carcinoma in patients with positive estrogen receptors

The activity of sequentially administered hormonal therapy was investigated over 25 days in 25 patients with epithelial ovarian carcinoma who had estrogen receptor (ERc)-positive tumors. Patients received ethinyl estradiol (EE) (50 micrograms/d) on days 1 to 7 and medroxyprogesterone acetate (MPA) (400 mg/d) on days 8 to 25. Twenty-three patients completed one or more courses of treatment. There were no complete responses (CR). Four partial responses (PR) with durations of 9, 4, 3, and 1 months were seen. Two incomplete responses with durations of 6 and 4 months were also seen. Six patients had stable disease (SD), and 11 patients had progression. The overall response rate was 17% and may represent a modest improvement in response over those in previously published studies conducted with MPA alone. No significant toxic effects were noticed, and some patients reported an improved sense of well-being. However, two patients experienced depression with this treatment. The mean ERc values in responders, patients with SD, and nonresponders were 70.0, 36.7, and 47.9 fmol/mg cytosolic protein, respectively. Future studies of hormonal therapy in patients with ovarian carcinoma should attempt to identify more reliable indices for determining sensitivity to these agents.

Ratio of polyclonal-monoclonal prostate-specific antigen levels. Discrimination of nodal status in prostate tumors that produce low marker levels

The preliminary data we present in this report suggest that the ratio of polyclonal-monoclonal serum prostate-specific antigen levels may add clinically useful information to that obtained using serum prostate-specific antigen levels alone. We hypothesize that the diversity of prostate-specific antigen ratios observed in our data reflects a diversity in the antigenic and structural attributes of prostate-specific antigen molecules found in the sera of patients with prostate cancer. Further, this heterogeneity of molecules is a reflection of the diverse and altered metabolic state of human prostate cancer and appears to be related to biologic behavior in individual patients.

Ki-67 immunostaining in node-negative stage I/II breast carcinoma. Significant correlation with prognosis

Prognostic predictors for node-negative breast carcinoma have not been clearly established. Immunostaining with Ki-67 antibody was performed on frozen sections of histologically proved node-negative breast carcinomas from 42 patients to examine its prognostic value and its association with other clinicopathologic and biochemical parameters, i.e., patient age and tumor size, histologic type, nuclear grade, mitotic rate, presence of vascular or lymphatic invasion, DNA ploidy, percentage of cells in S-phase, estrogen content, and c-erbB-2 amplification. Thirty-seven of the 42 tumors showed immunoreactivity with Ki-67 antibody in 1% to 55% of the tumor cells. A strongly significant correlation was observed between Ki-67 staining percentage and, respectively, nuclear grade, age, and mitotic rate. Nuclear grade 1 (the most anaplastic) tumors showed a significantly higher median percentage of cells stained (median, 14; range, 3 to 40) compared with nuclear grade 3 tumors (median, 0.5; range, 0 to 8). Thirteen patients developed recurrence; six of them died of disease. On univariate analysis, both 5-year disease-free and overall survivals were strongly associated with percentage of cells stained with Ki-67 antibody. Our results suggest that Ki-67 immunostaining correlates well with nuclear grade and clinical outcome in node-negative breast carcinoma. Because of small sample size analyzed in this study we were unable to do multivariate analysis. Therefore, further studies with larger number of cases are needed to determine whether tumor proliferative activity determined by Ki-67 immunostaining is an independent prognostic parameter or it merely reflects histopathologic features such as nuclear grade or mitotic activity.

Carcinoembryonic antigen in serum of patients with colorectal polyps: correlation with histology and smoking status

To measure the concentration of carcinoembryonic antigen (CEA) in serial serum specimens of 47 healthy subjects and in serial sera of 59 patients with colorectal polyps of confirmed histology, obtained before or after (sometimes both) polypectomy, we used the Roche EIA and the Hybritech Tandem-E double monoclonal immunoenzymometric assays. Both methods gave comparable results for the healthy subjects but discordant values for some polyp patients. The Tandem-E test gave increased CEA results more frequently for two groups of polyp patients, the group of ex-smokers with neoplastic polyps (n = 14) and the group of smokers (n = 20). Smokers had significantly greater (P less than 0.025) mean concentrations of serum CEA than did nonsmokers, irrespective of whether they were healthy or had colorectal polyps. Smokers with recurrent polyps demonstrated significantly greater (P less than 0.050) mean concentrations of serum CEA than did smokers with a first occurrence of polyps. Polypectomy was followed by statistically significant decreases (P less than 0.050) of mean concentrations of serum CEA, primarily in polyp patients who were smokers. However, although CEA increases occurred frequently in polyp patients who smoked, these abnormalities did not fully correlate with polyp histology.

Carcinoembryonic antigen in serum of patients with colorectal polyps: correlation with histology and smoking status

To measure the concentration of carcinoembryonic antigen (CEA) in serial serum specimens of 47 healthy subjects and in serial sera of 59 patients with colorectal polyps of confirmed histology, obtained before or after (sometimes both) polypectomy, we used the Roche EIA and the Hybritech Tandem-E double monoclonal immunoenzymometric assays. Both methods gave comparable results for the healthy subjects but discordant values for some polyp patients. The Tandem-E test gave increased CEA results more frequently for two groups of polyp patients, the group of ex-smokers with neoplastic polyps (n = 14) and the group of smokers (n = 20). Smokers had significantly greater (P less than 0.025) mean concentrations of serum CEA than did nonsmokers, irrespective of whether they were healthy or had colorectal polyps. Smokers with recurrent polyps demonstrated significantly greater (P less than 0.050) mean concentrations of serum CEA than did smokers with a first occurrence of polyps. Polypectomy was followed by statistically significant decreases (P less than 0.050) of mean concentrations of serum CEA, primarily in polyp patients who were smokers. However, although CEA increases occurred frequently in polyp patients who smoked, these abnormalities did not fully correlate with polyp histology.

Monoclonal prostate-specific antigen in untreated prostate cancer. Relationship to clinical stage and grade

The authors evaluated 440 men with clinically staged and untreated prostate cancer with a monoclonal prostate-specific antigen (PSA) assay. The serum PSA value correlated significantly with both the stage and grade of disease (P less than 0.00005). The relationships between PSA and consecutive Stages A, B, C, and D2 (alpha = 0.15) and between progressive Gleason's scores 2 to 4, 5 to 7, and 8 to 10 (alpha = 0.15) were statistically significant. Also statistically significant was the correlation between serum PSA level and intracapsular versus extracapsular disease (P less than 0.00005), although no one value can be used to differentiate reliably between patients in these two categories. The probability of clinically detectable metastasis (Stage D2) is 85% if the serum PSA level is greater than 30; however, 12% of patients without clinical evidence of metastases (Stages A, B, and C) have such a serum PSA value. Despite the statistically significant association between PSA and tumor differentiation and volume as reflected by tumor grade and clinical stage, this marker cannot be used to determine either for an individual patient.

Plasma protein-bound sialic acid in patients with colorectal polyps of known histology

Protein-bound sialic acid (PBSA) was measured in serial plasma specimens from 62 healthy subjects, 48 patients with colorectal polyps, and 30 patients with colorectal adenocarcinomas. The mean plasma PBSA concentration in healthy smokers was significantly greater than that in healthy nonsmokers and healthy ex-smokers (P less than 0.0001). Villoglandular polyps were associated with higher plasma PBSA values than were the most benign hyperplastic polyps (P less than 0.025). Patients with the most neoplastic villoglandular and villous polyps had significantly greater (P less than 0.010-0.050) plasma PBSA values than healthy subjects. Polypectomy decreased the mean PBSA value significantly to the mean value for healthy subjects only for patients with villoglandular (P less than 0.010) or villous (P less than 0.050) polyps. Colorectal cancer patients had mean plasma PBSA concentrations significantly greater than those for the healthy subjects (P much less than 0.001) and the polyp patients (P much less than 0.001). Surgery significantly reduced (P less than 0.025) the mean PBSA value for the cancer patients to the mean PBSA value observed for the healthy subjects.

Measurement of estrogen and progesterone receptors in human breast tumors: enzyme immunoassay versus binding assay

To determine whether we could replace our current binding assay (BA) method for measurement of estrogen receptors (ERs) and progesterone receptors (PRs) with the recently developed enzyme immunoassay (EIA) method, we compared simultaneous measurements of ERs and PRs in frozen breast tumor samples by both methods. A value of greater than or equal to 10 fmol/mg cytosol protein was defined as positive. There was agreement between the BA and EIA on whether the sample was positive or negative in 75 of 91 (82%) samples measured for ERs and in 74 of 93 (80%) for PRs. When the threshold value for a positive assay was redefined as greater than or equal to 20 fmol/mg protein, there was agreement in 85 of 91 (93%) samples for ERs and 85 of 93 (91%) for PRs. The numerical value for ERs by EIA was not consistently greater or less than ERs by BA, but the difference between the EIA and BA measurement increased as the size of the measurement increased. We did not see an excess of premenopausal patients whose ERs by BA were negative and whose ERs by EIA were positive. Although we performed a linear regression analysis and determined the Pearson correlation coefficient to compare the BA and EIA as reported by others, we show that this analysis may be misleading when the objective is to demonstrate similarities between these methods. Our study shows that the EIA can be confidently used in place of the BA. However, a threshold value for a positive EIA should be confirmed clinically in future studies.