Human pancreatic carcinomas and cell lines reveal frequent and multiple alterations in the p53 and Rb-1 tumor-suppressor genes.

The molecular pathology of human pancreatic cancer is poorly understood, particularly with regard to the role of known tumor-suppressor genes. We have examined the expression of the p53 and Rb-1 tumor-suppressor genes in seven human pancreatic carcinoma cell lines and 10 primary pancreatic carcinomas. Examination of the Rb-1 gene by Northern hybridization and immunoprecipitation analyses revealed the absence of Rb-1 protein expression in two cell lines. Moreover, regions of absent nuclear staining in two primary pancreatic carcinomas were detected by immunohistochemical analysis. Investigation of p53 by Southern, Northern, immunohistochemical and immunoprecipitation analyses revealed multiple abnormalities, including gross rearrangements in two cell lines, the absence of detectable p53 transcript in two cell lines and a truncated transcript in one line. Six cell lines overexpressed p53 protein, while one line revealed the absence of p53 product by immunohistochemical and immunoprecipitation analyses. Sequence analysis of exons 5-8 of the p53 gene confirmed these analyses, revealing missense mutations in all seven cell lines in codons 181, 220, 248, 249, 265, 272 and 273. Of 10 mutations identified, nine were transitions and 50% were in codon 273. Immunohistochemical analyses of frozen primary pancreatic carcinomas revealed positive nuclear staining for p53 in 40% of cases. Mutations were identified in codons 238 and 286 and in intron 9 in several representative specimens. Alterations in the p53 and Rb-1 genes may be important features in the development of human pancreatic cancer.

Dose-escalation and pharmacodynamic study of topotecan in combination with cyclophosphamide in patients with refractory cancer.

PURPOSE: Based on preclinical data that demonstrated synergy between alkylating agents and topoisomerase (topo) I poisons, we determined the maximum-tolerated dose (MTD) of topotecan, using a 5 day bolus schedule, that could be given in combination with a single, fixed dose of cyclophosphamide. Pharmacodynamics of this combination were explored by analyzing biochemical effects of treatment in peripheral-blood mononuclear cells (PBMCs). PATIENTS AND METHODS: Patients with refractory cancer were treated with cyclophosphamide 600 mg/m2 on day 1, followed by topotecan given as a 30-minute infusion for 5 consecutive days. Cycles were repeated every 3 weeks. Once the MTD was defined, granulocyte colony-stimulating factor (G-CSF) was added to the regimen in an attempt to escalate further the dose of topotecan. Plasma concentrations of topotecan were determined during the first treatment cycle by high-performance liquid chromatography. PBMCs were sampled at baseline and throughout the 5-day treatment period for analysis of topo I protein concentrations and to determine drug-induced DNA fragmentation. RESULTS: Twenty-six patients were treated with topotecan at doses that ranged from 0.5 mg/m2/d to 1.2 mg/ m2/d for a total of 74 cycles. Reversible neutropenia was dose-limiting, with mild to moderate suppression of the other blood-cell elements commonly occurring. Transfusions of RBCs and platelets were required in 24% and 7% of treatment cycles, respectively. The most prominent nonhematologic toxicities were fatigue and weight loss. Compared with previously published data in which topotecan was administered alone, cyclophosphamide did not appear to alter the pharmacokinetics of topotecan. Significant increases in topo I concentration were identified in PBMCs following the administration of cyclophosphamide on day 1 and there was a significant decrease in topo 1 during the 5-day course of treatment (P < .01, sign test). DNA fragmentation as a result of drug treatment was identified in 11 of 15 (73%) cycles analyzed. CONCLUSION: For previously treated patients, the recommended dose of topotecan in this schedule is 0.75 mg/m2/d without growth factor support and 1.0 mg/ m2/d if it is administered with G-CSF. Biochemical changes in cells induced by exposure to camptothecins can be measured in vivo and these effects may have important implication in the design of combination therapies and the optimal scheduling of this class of agents.

Flow cytometric analysis of deoxyribonucleic acid in human granulosa cells as a function of chronological age and ovulation induction regimen.

We examined whether the proliferative index of granulosa cells as determined by flow cytometry varied with a women's age or ovulation induction regimen that included leuprolide acetate (LA). This prospective cohort study included three groups of patients undergoing assisted reproductive technologies. Group I consisted of 9 women age less than or equal to 30 yr, who received LA plus human menopausal gonadotropin (hMG). Group II included 9 women age more than or equal to 40 yr, who received LA plus hMG. Group III consisted of 6 women age less than or equal to 30 yr who received hMG alone. A total of 79 preovulatory follicles containing greater than 10(4) granulosa cells were obtained from these 24 women and examined by flow cytometry. Group I was compared to group II to match for ovulation induction regimen and to examine proliferative index as a function of age. Group I was compared to group III to match for age and to examine proliferative index as a function of ovulation induction regimen. Outcome measures included proliferative index of granulosa cells as a function of age, ovulation induction regimen, ampules of hMG, estradiol on day of hCG, and serum FSH. Group I demonstrated a greater proliferative index than group II: 23.4% +/- 1.4 vs. 18.4% +/- 0.96 (P less than 0.01). Group I had a greater proliferative index than group III: 23.4% +/- 1.4 vs. 11.9 +/- 0.61 (P less than 0.001). Although both age and the presence of LA appeared to affect the PI, multiple linear regression demonstrated that only the addition of LA and not age, per se, had an independent effect upon granulosa cells undergoing proliferation (P less than 0.0005). We conclude that LA followed by hMG leads to an increase in the percentage of granulosa cells undergoing proliferation when compared to ovulation induction regimens that include hMG alone. Chronological age does not appear to have a significant independent influence upon the proliferative index.

Presymptomatic testing using DNA markers for individuals at risk for familial multiple endocrine neoplasia 2A.

The carrier status of 39 at-risk individuals in 6 multiple endocrine neoplasia 2A families was determined using a DNA based test. We were able to calculate a virtual diagnosis (probability greater than 95%) for 77% of the individuals and a probable diagnosis (probability greater than 90%) for 90% of the individuals. This study points out some of the problems of specific pedigree structures that can affect the risk calculation. This study further shows that no single test based on either biochemistry, pathology, or genetics can consistently and unambiguously produce a presymptomatic diagnosis. We also describe two specific examples where DNA testing has helped to resolve clinical uncertainties in at-risk individuals.

Gonadotropin-releasing hormone agonist-induced differences in granulosa cell cycle kinetics are associated with alterations in follicular fluid müllerian-inhibiting substance and androgen content.

We have previously shown that the proliferative index (PI), as determined by flow cytometry of luteinized granulosa cells obtained at oocyte retrieval, is greater in ovulation induction regimens which include the GnRH analog (GnRH-a) leuprolide acetate than those using human menopausal gonadotropin (hMG) only. Specific growth factors or intrafollicular hormones may contribute to this leuprolide acetate-induced difference in cell cycle kinetics. We examined whether differences in the PI of these granulosa cells are associated with the alterations of follicular fluid content of Mullerian-inhibiting substance (MIS) and other intrafollicular hormones including FSH, estradiol, progesterone, androstenedione, and testosterone. The control group consisted of follicular fluid obtained from 18 follicles from 4 women receiving hMG alone. The GnRH-a treated group consisted of follicular fluids obtained from 55 follicles aspirated from 18 women receiving GnRH-a in addition to hMG. One-way analysis of variance using log-transformed data and expressed as geometric means with 95% confidence intervals, demonstrated that the follicles from the control group had a significant 14-fold higher concentration of 2.46 ng/mL MIS, 95% CI (1.8-4.8) vs. 0.18 ng/mL, 95% CI (0.13-0.24) P < 0.0005, a 3-fold higher concentration of 17.55 nmol/L androstenedione, 95% CI (14.6-20.9) vs. 5.76 nmol/L, 95% CI (3.1-10.5) P < 0.02, and a 1.5-fold higher concentration of 29.43 nmol/L testosterone 95% CI (22.5-38.14) vs. 19.3 nmol/L, 95% of CI (11.1-33.9) P < 0.01 than GnRH-a treated follicles, although the PI value in controls was half that of the GnRH-a group. These data demonstrate that GnRH-a induced differences in granulosa cell cycle kinetics are associated with alterations of MIS and androgen intrafollicular fluid content and suggest that MIS may be a mitotic inhibitor of human granulosa cells.

Preoperative serum prostate-specific antigen and Gleason grade as predictors of pathologic stage in clinically organ confined prostate cancer: implications for the choice of primary treatment.

PURPOSE: Despite careful preoperative staging, approximately 50% of patients who undergo radical prostatectomy for clinical stage A2 (T1b-c) and B (T2) prostate cancer are found to have pathologic stage C (T3-4) or D (N1) disease. This study investigates whether preoperative serum prostate specific antigen (PSA) and Gleason grade predict pathologic stage among patients with clinically organ confined prostate cancer. METHODS: The records of all 63 patients who underwent attempted pelvic lymphadenectomy and radical prostatectomy for adenocarcinoma of the prostate at our institution in 1990-91 were retrospectively reviewed. RESULTS: Patients with a preoperative serum PSA of 12.5 ng/mL or greater had an 81% incidence of pathologic upstaging to stage C (T3-4) or D (N1) compared with 38% for patients with a PSA less than 12.5 (p = 0.0015). The incidence of various pathologic findings for prostate specific antigen > or = 12.5 vs. prostate specific antigen < 12.5 was as follows: seminal vesicle involvement 29% vs. 5% (p = 0.0186), lymph node metastases 24% vs. 0% (p = 0.0029), capsular penetration 71% vs. 38% (p = 0.0424), and positive margins 47% vs. 36% (p = 0.56). None (0/3) of the patients with Gleason grade 4 or less were pathologically upstaged compared with 49% (24/49) of patients with grade 5-7 tumors (p = 0.15) and 82% (9/11) of patients with grade 8 or higher cancers (p = 0.0474, grade 5-7 vs. 8-10). Within the group of patients with Gleason grade 5-7, a prostate specific antigen of 12.5 ng/mL or greater predicted an 79% rate of upstaging compared with 37% for patients with prostate specific antigen less than 12.5 (p = 0.0098). CONCLUSION: Patients with clinical Stage A2 (T1b-c) or B (T2) prostate cancer who have Gleason grade 8-10 tumors and those patients with Gleason grade 5-7 tumors with a preoperative serum prostate specific antigen of 12.5 ng/mL or higher have a high incidence of pathologic upstaging. These patients should be preferentially treated with external beam radiation in most cases.

Local recurrence versus new primary: clinical analysis of 82 breast relapses and potential applications for genetic fingerprinting.

PURPOSE: The purpose of this study was to perform a detailed clinical pathological analysis of breast relapses in patients treated with conservative surgery and radiation therapy in an effort to classify those relapses as true local recurrences or second primary tumors, and to assess the prognostic and therapeutic implications of such a classification system. METHODS AND MATERIALS: Of 990 patients treated with conservative surgery and radiation therapy at our facilities prior to December 1987, 82 patients have experienced a relapse in the conservatively treated breast as the primary site of failure. Patients were classified as having new primary tumors if they fulfilled any one of the following criteria: a) breast relapse occurring at a site distinctly removed from the original tumor; b) histology of the breast relapse compared with the original tumor consistent with a new primary; or c) DNA flow cytometry converting from an aneuploid primary to a diploid relapse. RESULTS: As of 2/92, with a median follow-up of 5.4 years from the time of breast relapse, the overall 5-year survival rate following breast relapse was 55%. Forty-seven patients were classified as true recurrences and 33 patients were classified as new primaries. Patients classified as true recurrences had a shorter median time to breast relapse than patients classified as new primaries (3.16 years vs. 5.42 years, p < .05) and an inferior post breast recurrence survival rate compared to patients classified as new primaries (36% vs. 89%, p < .05). Residual disease outside of the recurrent tumor bed was also noted to be more frequent in patients classified as true recurrences compared to patients classified as new primaries (48% vs. 16%, p < .05). CONCLUSION: Based on the clinical and pathological criteria outlined, it appears that a significant portion of patients experiencing a relapse in the conservatively treated breast may have new primary tumors as opposed to true local relapses. Distinction between a true recurrence and a new primary tumor may have significant prognostic implications. Uncertainties associated with the clinical and pathological criteria are presented and further investigations with genetic fingerprinting techniques to establish the clonality of breast relapses are presented and discussed.

Ovarian serous borderline tumors with lymph node involvement. Clinicopathologic and DNA content study of seven cases and review of the literature.

Although several studies have established the excellent prognosis of ovarian serous borderline tumors (OSBTs) in general, the significance of lymph node involvement has not been thoroughly addressed. In this article, we describe seven OSBTs with lymph node involvement and their DNA content and S-phase fraction. Lymph node involvement was identified at presentation in four cases (pelvic, paraaortic, and omental) and after 4, 5, and 7 years in the other three (omental, scalene, and cervical, respectively). In the first group, clusters of cells cytologically similar to those of the OSBT were identified in the nodal sinusoids in all four cases and focally in the lymph node parenchyma in three of them. In contrast, the involved lymph nodes of the three cases with delayed nodal disease showed an almost complete replacement by tumor. In one of them, the tumor in the lymph node was histologically similar to the OSBT, while in the other two cases the tumor was more solid and poorly differentiated, suggesting true metastatic disease. Flow cytometric analysis of nuclear DNA content and S-phase fraction were performed on paraffin-embedded tissue of all of the primary OSBTs and of the involved lymph nodes in six cases; diploid DNA content and low S-phase fraction were seen in all cases. All patients were alive and free of disease 2-9 years after initial diagnosis. While the clinical significance of LN involvement in OSBT is still uncertain, DNA ploidy analysis seems to be unable to identify those cases at risk for tumor progression.

The histology of interstitial cystitis.

Several studies have reported histologic findings in interstitial cystitis (IC) bladder biopsy specimens. However, these studies used a variety of criteria to define IC, which may explain the variation noted in the histologic changes. Clinical experience shows that these biopsy specimens are often not helpful in confirming the diagnosis. Our study was designed to examine the histologic features identified in bladder biopsy specimens from patients with IC and compare them with biopsy specimens from a control population. Although IC patients as a group had a higher incidence and degree of denuded epithelium, ulceration, and submucosal inflammation, none of these findings was pathognomonic. In addition, these findings occurred only in interstitial cystitis patients with pyuria or small bladder capacity. The inflammatory infiltrate seen in IC was composed predominantly of lymphocytes, with increasing numbers of plasma cells as the degree of inflammation increased. There was no specific predilection for the inflammatory infiltrate to be perineural. Submucosal inflammation was associated with denuded epithelium, ulceration, pyuria, and a clinical response to therapy suggesting a pathophysiologic relationship. Epithelial and basement membrane thickness, submucosal edema, vascular ectasia, fibrosis, and detrusor muscle inflammation and fibrosis were not significantly different in the IC and control patients. These findings suggest that IC is a chronic submucosal inflammatory disease, at least in those patients with small bladder capacities or pyuria. IC is best diagnosed from its clinical features; the histologic changes identified in the bladder biopsy play a supportive role in this diagnosis. Mast cells play a limited role in the diagnosis of IC.

Immunocytochemical identification of Rochalimaea henselae in bacillary (epithelioid) angiomatosis, parenchymal bacillary peliosis, and persistent fever with bacteremia.

We report the immunocytochemical identification of Rochalimaea henselae, a newly recognized fastidious, Gram-negative, Warthin-Starry-positive organism, as the common pathogen in bacillary angiomatosis (BA), bacillary peliosis (BP) of the liver and spleen, and persistent fever with bacteremia in immunocompromised patients. Immunogenic proteins of the R. henselae strain isolated from the blood of a febrile immunocompromised patient with BP of the liver were used to produce primary immune serum in rabbits. Using immunocytochemical procedures, the polyclonal antiserum reacted strongly not only with the immunizing strain of the bacteria, but also with other blood isolates of R. henselae (five cases) from both immunocompromised and immunocompetent patients and with the organisms present in the tissue lesions of cutaneous BA (five cases) and BP of the liver (two cases) and spleen (one case). The blood isolates and BA and BP tissue samples were obtained from widely separated geographic areas. The antiserum was weakly cross-reactive with cultures of Rochalimaea quintana, an organism closely related to R. henselae, but this reactivity was eliminated by specific adsorption. The antiserum did not cross-react with the Warthin-Starry-positive organisms associated with cat scratch disease (Afipia felis), syphilis (Treponema pallidum), Lyme disease (Borrelia burgdorferi) or chronic active gastritis (Helicobacter pylori). Likewise, the antiserum did not identify organisms in eight cases of Kaposi's sarcoma, a disorder of immunocompromised patients that is clinically similar to BA. Further studies are needed to determine the prevalence of this newly recognized organism as well as its possible involvement in other angioproliferative diseases.

Pulmonary meningiomas: a report of two cases.

Two intraparenchymal lung tumors exhibiting the histopathologic and immunophenotypic characteristics of an intracranial meningioma are presented. The meningiomas presented as solitary asymptomatic nodules in elderly individuals. Both patients survived longer than 3 years following resection, and neither displayed clinical or radiographic evidence of a central nervous system tumor, suggesting that these are primary lung tumors. Review of the literature and discussion of other lesions in the differential diagnosis of this rare intrapulmonary neoplasm are presented.

Intrapulmonary localized fibrous tumor. Intraparenchymal so-called localized fibrous mesothelioma.

This report describes three cases of intrapulmonary fibromas which are histologically identical to localized fibrous tumors of pleura (localized fibrous mesothelioma). Morphologically these tumors are characterized by a haphazard proliferation of cytologically bland spindle cells separated by variable amounts of wavy hyalinized collagen. Entrapped bronchiolar and alveolar epithelium is common. These spindle cells lack expression of cytoplasmic keratin, S-100 protein, desmin, and epithelial membrane antigen, but are strongly decorated for intracellular vimentin. The clinical behavior, differential diagnosis, and histogenesis of these lesions are discussed.

Management of ectopic thyroid nodules.

BACKGROUND: Surgical dictum states that the so-called lateral aberrant thyroid represents metastatic thyroid cancer. METHODS AND RESULTS: We present sixteen cases of patients with benign ectopic thyroid tissue. Seven cases were discovered during evaluation and treatment of hyperparathyroidism. The remaining nine cases were discovered during the evaluation and treatment of thyroid disorders or cervical nodules. In fifteen cases there is benign histology on the nodules. One case has been followed for 4 years with scans revealing a normal thyroid gland with an unchanging ectopic thyroid nodule in the superior mediastinum. In eight of our cases there have been thyroid resections searching for occult carcinomas. Histologic examination on these eight thyroid glands revealed either normal thyroid or benign nodules. CONCLUSIONS: Not all lateral aberrant thyroid tissue is malignant. The histologic condition of the nodule combined with intraoperative examination of the ipsilateral thyroid lobe can reliably guide therapy. The old dictum concerning lateral aberrant thyroid representing metastatic cancer should be removed from or modified in review texts and surgical examinations.

Poorly differentiated ("insular") carcinoma of the thyroid gland: an aggressive subset of differentiated thyroid neoplasms.

Four patients with a histologically distinctive thyroid carcinoma--which recently has been referred to as poorly differentiated ("insular") carcinoma--are reported. This study confirms the previous conclusions that patients with this neoplasm often experience an aggressive clinical course, with focal recurrences and distant metastases common, which results in death in the majority of patients. Such aggressive behavior may occur even when the insular component accounts for only a small percentage of an otherwise well-differentiated carcinoma, as seen in one of our patients. After subtotal or total thyroidectomy, three of the four patients have experienced local recurrence (1) and metastases to lung (3), mediastinum (1), and bone (1). All three of these patients died within 2 years of the diagnosis of insular carcinoma. The remaining patient is alive without evidence of disease 1 year after total thyroidectomy. Histologically, this neoplasm is characterized by well-defined nests (insulae) that are composed of relatively small, uniform cells and sometimes associated with small, thyroglobulin-containing follicles. Tumor necrosis is often present. Insular carcinoma may comprise the entire neoplasm (2 patients) or be associated with well-differentiated follicular (1 patient) or papillary (1 patient) carcinoma. The rapid and often fatal course associated with insular carcinoma warrants aggressive treatment at the time of initial diagnosis, including total thyroidectomy and node dissection (if involved), as well as possible iodine-131, external beam irradiation and chemotherapy.

The efficacy of simultaneous fine-needle aspiration and large-needle biopsy of the thyroid gland.

Fine-needle aspirations and cutting needle biopsies were performed on 415 patients with solitary thyroid nodules. All nodules were considered hypofunctioning by scintiscans. Specimens were adequate in 399 patients. Ten percent of these patients had thyroid cancers documented by thyroidectomies. Results from either or both procedures were positive or suspicious in 58 patients (14.5%). Thyroid cancers were found in 40 of the 58 patients (69%). Aspirates alone detected 34 of 40 cancers (85%) and biopsy specimens alone detected 30 of 40 cancers (75%). All thyroid cancers were detected when both results were considered together, demonstrating that needle aspirates and cutting needle biopsies are complementary. The difficulty of making definitive diagnoses of follicular neoplasms by needle aspirates or cutting needle biopsies is reemphasized.

Independent modulation of enterocyte migration and proliferation by growth factors, matrix proteins, and pharmacologic agents in an in vitro model of mucosal healing.

BACKGROUND: Gastrointestinal mucosa heals by restitution and proliferation. These are difficult to distinguish in vivo. METHODS: Human Caco-2 enterocytes were cultured on matrix proteins (collagen I, laminin, fibronectin) with growth factors (epidermal growth factor [EGF] and transforming growth factor-beta 1 [TGF-beta 1]) and the tyrosine kinase and prostaglandin inhibitors genistein and indomethacin. Healing was modeled by means of monolayer expansion, proliferation by means of 3H-thymidine uptake, and restitution by means of mitomycin-blocked migration. RESULTS: Changing matrix composition failed to alter proliferation, but collagen I stimulated migration more than laminin or fibronectin (laminin/collagen, 68% +/- 2%; p less than 0.05). EGF (30 ng/ml) increased proliferation on both collagen (225% +/- 11% of basal) and laminin (206% +/- 26%) but increased migration only over laminin (210% +/- 17%) (all, p less than 0.05). TGF-beta 1 (200 pg/ml) stimulated migration over laminin (187% +/- 18%, p less than 0.005) but inhibited migration over collagen (89% +/- 3%, p less than 0.01) and did not affect 3H-thymidine uptake. When cultured on laminin, EGF but not TGF-beta 1 altered organization of the alpha 2 integrin subunit. Genistein (100 mumol/L) inhibited basal and EGF-stimulated 3H-thymidine uptake. In addition, it prevented EGF stimulation of replication-blocked migration (81% +/- 10% vs 190% +/- 20% of basal, p less than 0.0001) without altering basal replication-blocked migration. Indomethacin (10(-5) mol/L) did not alter migration but inhibited basal and EGF-stimulated proliferation by 7% +/- 1% (each, p less than 0.005). CONCLUSIONS: Restitution and proliferation appear independently regulated by matrix and growth factors. It may be possible to individually target specific phases of mucosal healing by means of pharmacologic agents.

P-glycoprotein expression and multidrug resistance in adrenocortical carcinoma.

BACKGROUND: The response of adrenocortical carcinoma (ACC) to adjuvant chemotherapy has been disappointing with no significant impact on survival. The normal adrenal cortex has very high levels of P-glycoprotein, an energy-dependent efflux pump of a variety of structurally unrelated chemotherapeutic agents. P-glycoprotein has been implicated as a cause of multidrug resistance in a variety of neoplasms. The purpose of this study was to evaluate P-glycoprotein expression in ACC. METHODS: Eleven patients with ACC had paraffin-embedded tumor evaluated for P-glycoprotein expression. These were analyzed by immunohistochemistry assay with a battery of four anti-P-glycoprotein antibodies (MRK-16, JSB-1, UIC-2, MDR). RESULTS: All eleven cases showed intense, predominantly membrane immunoreactivity for P-glycoprotein. In 10 of the cases, most tumor cells were immunoreactive with at least three antibodies, and six of 11 cases were positive for all four antibodies. In this small series no correlation existed between P-glycoprotein expression and tumor grade, stage of disease, or survival. CONCLUSIONS: All 11 cases of ACC studied showed P-glycoprotein expression, which was similar to the normal adrenal cortex. This possible mechanism of multidrug resistance may help explain the significant chemoresistance seen in ACC.

Parathyroid carcinoma: the relationship of nuclear DNA content to clinical outcome.

This article reports the use of flow cytometry to determine tumor nuclear DNA content and its correlations with clinical outcome in a series of patients with parathyroid carcinoma. Information concerning nine patients with parathyroid cancer (aged 25 to 88 years) was reviewed. Paraffin-embedded, formalin-fixed archival tissue was used to determine tumor DNA content flow cytometrically. Twenty-five operative procedures were performed in nine patients, including 11 parathyroidectomies, two wide local excisions, six central neck dissections, and four median sternotomies for resection of metastases. With flow cytometry used to determine a tumor DNA index, five patients had evidence of tumor aneuploidy; in two patients two aneuploid peaks were evident. The DNA index ranged from 0.7 (hypodiploid) to 1.92 (mean, 1.31). Follow-up ranged from 1 to 18 years. Four patients died. Five were alive 1 to 13 years after diagnosis of parathyroid disease. Four of the five patients with evidence of tumor aneuploidy had metastatic disease and died, and the fifth has had three local recurrences. The four patients with diploid tumors were alive and free of disease 1, 3, 4, and 8 years after the initial operation. It is concluded that in patients with clinically or pathologically demonstrated parathyroid cancer, flow cytometry may help differentiate those whose cancers are likely to behave indolently (diploid tumors) from those with tumors (aneuploid) more likely to behave aggressively by recurring locally or metastasizing.

Mechanism of technetium 99m sestamibi parathyroid imaging and the possible role of p-glycoprotein.

BACKGROUND: Localization of parathyroid glands is critical in the treatment of recurrent or persistent hyperparathyroidism. Technetium sestamibi imaging may improve localization; however, the mechanism of visualization of parathyroid tissue remains unclear. On the basis of the chemical structure of sestamibi it has been suggested that p-glycoprotein is involved in the transport of sestamibi across cell membranes. This study was designed to examine sestamibi uptake and retention and p-glycoprotein expression in normal and abnormal parathyroid tissue. METHODS: Thirty-two consecutive patients underwent 2-methoxy-isobutyl-isonitrile imaging immediately before parathyroid exploration. Tissue was obtained from normal and abnormal parathyroids and from the thyroid gland. Touch preparations gave rapid confirmation of tissue origin. Specimens were trimmed and weighed, and gamma-emission was counted. Percentage injected dose per gram of tissue was calculated. Immunohistochemistry was obtained with a battery of monoclonal antibodies to identify p-glycoprotein in parathyroid tissue submitted for permanent histologic examination. Slides were graded by a pathologist familiar with immunohistochemistry. RESULTS: Abnormal parathyroid tissue had a higher mean retention of injected dose per gram than did normal thyroid and parathyroid tissue. Immunohistochemistry revealed that abnormal parathyroid tissue expresses less p-glycoprotein. CONCLUSIONS: These results suggest that size is not the single determinant of parathyroid visualization and that p-glycoprotein expression may be involved in the mechanism of parathyroid imaging.

Trifluoperazine as a modulator of multidrug resistance in refractory breast cancer.

Overexpression of P-glycoprotein (P-gp) has been implicated as the mechanism of multidrug resistance (MDR) in a number of human cancers, including carcinoma of the breast. We conducted a clinical trial to determine whether the P-gp inhibitor, trifluoperazine, could sensitize patients with refractory breast cancer to vinblastine chemotherapy. Adult patients with histologically confirmed, refractory, advanced breast cancer were treated with vinblastine at a dose of 1.7 mg/m2 per day by continuous infusion for five consecutive days. Patients who did not respond after two cycles were subsequently treated with vinblastine plus trifluoperazine at a dose of 8 mg twice daily during the five days of chemotherapy. In patients from whom tumor samples were available, the expression of P-gp was determined by immunocytochemistry. Of 35 patients enrolled, 30 were evaluable, 2 of whom (7%) achieved a partial response to vinblastine alone. Among the 16 patients treated with vinblastine plus trifluoperazine there was one response (6%) which lasted 16 weeks. Tumor samples were available from 16 patients, and 14 (87%) were immunoreactive for P-pg. P_pg expression was detected both in the patient who responded to vinblastine plus trifluoperazine and in one of the two patients who responded to vinblastine alone. Continuous-infusion vinblastine demonstrated limited activity in this study. Furthermore, trifluoperazine did not effectively reverse established resistance to vinblastine. This failure may be related the presence of multiple mechanisms of drug resistance in the heavily pretreated population, or because ineffective concentrations of the modulator were achieved in vivo. Future studies should evaluate more effective modulators, and attempt to reverse MDR earlier in the course of treatment, before other forms of resistance can develop.