A comparison of three methods for detecting KRAS mutations in formalin-fixed colorectal cancer specimens.

BACKGROUND: KRAS mutation testing is required to select patients with metastatic colorectal cancer (CRC) to receive anti-epidermal growth factor receptor antibodies, but the optimal KRAS mutation test method is uncertain. METHODS: We conducted a two-site comparison of two commercial KRAS mutation kits - the cobas KRAS Mutation Test and the Qiagen therascreen KRAS Kit - and Sanger sequencing. A panel of 120 CRC specimens was tested with all three methods. The agreement between the cobas test and each of the other methods was assessed. Specimens with discordant results were subjected to quantitative massively parallel pyrosequencing (MPP). DNA blends were tested to determine detection rates at 5% mutant alleles. RESULTS: Reproducibility of the cobas test between sites was 98%. Six mutations were detected by cobas that were not detected by Sanger, and five were confirmed by MPP. The cobas test detected eight mutations which were not detected by the therascreen test, and seven were confirmed by MPP. Detection rates with 5% mutant DNA blends were 100% for the cobas and therascreen tests and 19% for Sanger. CONCLUSION: The cobas test was reproducible between sites, and detected several mutations that were not detected by the therascreen test or Sanger. Sanger sequencing had poor sensitivity for low levels of mutation.

The HOX homeodomain proteins block CBP histone acetyltransferase activity.

Despite the identification of PBC proteins as cofactors that provide DNA affinity and binding specificity for the HOX homeodomain proteins, HOX proteins do not demonstrate robust activity in transient-transcription assays and few authentic downstream targets have been identified for these putative transcription factors. During a search for additional cofactors, we established that each of the 14 HOX proteins tested, from 11 separate paralog groups, binds to CBP or p300. All six isolated homeodomain fragments tested bind to CBP, suggesting that the homeodomain is a common site of interaction. Surprisingly, CBP-p300 does not form DNA binding complexes with the HOX proteins but instead prevents their binding to DNA. The HOX proteins are not substrates for CBP histone acetyltransferase (HAT) but instead inhibit the activity of CBP in both in vitro and in vivo systems. These mutually inhibitory interactions are reflected by the inability of CBP to potentiate the low levels of gene activation induced by HOX proteins in a range of reporter assays. We propose two models for HOX protein function: (i) HOX proteins may function without CBP HAT to regulate transcription as cooperative DNA binding molecules with PBX, MEIS, or other cofactors, and (ii) the HOX proteins may inhibit CBP HAT activity and thus function as repressors of gene transcription.

HOXA9 forms triple complexes with PBX2 and MEIS1 in myeloid cells.

Aberrant activation of the HOX, MEIS, and PBX homeodomain protein families is associated with leukemias, and retrovirally driven coexpression of HOXA9 and MEIS1 is sufficient to induce myeloid leukemia in mice. Previous studies have demonstrated that HOX-9 and HOX-10 paralog proteins are unique among HOX homeodomain proteins in their capacity to form in vitro cooperative DNA binding complexes with either the PBX or MEIS protein. Furthermore, PBX and MEIS proteins have been shown to form in vivo heterodimeric DNA binding complexes with each other. We now show that in vitro DNA site selection for MEIS1 in the presence of HOXA9 and PBX yields a consensus PBX-HOXA9 site. MEIS1 enhances in vitro HOXA9-PBX protein complex formation in the absence of DNA and forms a trimeric electrophoretic mobility shift assay (EMSA) complex with these proteins on an oligonucleotide containing a PBX-HOXA9 site. Myeloid cell nuclear extracts produce EMSA complexes which appear to contain HOXA9, PBX2, and MEIS1, while immunoprecipitation of HOXA9 from these extracts results in coprecipitation of PBX2 and MEIS1. In myeloid cells, HOXA9, MEIS1, and PBX2 are all strongly expressed in the nucleus, where a portion of their signals are colocalized within nuclear speckles. However, cotransfection of HOXA9 and PBX2 with or without MEIS1 minimally influences transcription of a reporter gene containing multiple PBX-HOXA9 binding sites. Taken together, these data suggest that in myeloid leukemia cells MEIS1 forms trimeric complexes with PBX and HOXA9, which in turn can bind to consensus PBX-HOXA9 DNA targets.

Overexpression of HOXA10 in murine hematopoietic cells perturbs both myeloid and lymphoid differentiation and leads to acute myeloid leukemia.

Multiple members of the A, B, and C clusters of Hox genes are expressed in hematopoietic cells. Several of these Hox genes have been found to display distinctive expression patterns, with genes located at the 3' side of the clusters being expressed at their highest levels in the most primitive subpopulation of human CD34+ bone marrow cells and genes located at the 5' end having a broader range of expression, with downregulation at later stages of hematopoietic differentiation. To explore if these patterns reflect different functional activities, we have retrovirally engineered the overexpression of a 5'-located gene, HOXA10, in murine bone marrow cells and demonstrate effects strikingly different from those induced by overexpression of a 3'-located gene, HOXB4. In contrast to HOXB4, which causes selective expansion of primitive hematopoietic cells without altering their differentiation, overexpression of HOXA10 profoundly perturbed myeloid and B-lymphoid differentiation. The bone marrow of mice reconstituted with HOXA10-transduced bone marrow cells contained in high frequency a unique progenitor cell with megakaryocytic colony-forming ability and was virtually devoid of unilineage macrophage and pre-B-lymphoid progenitor cells derived from the transduced cells. Moreover, and again in contrast to HOXB4, a significant proportion of HOXA10 mice developed a transplantable acute myeloid leukemia with a latency of 19 to 50 weeks. These results thus add to recognition of Hox genes as important regulators of hematopoiesis and provide important new evidence of Hox gene-specific functions that may correlate with their normal expression pattern.

AbdB-like Hox proteins stabilize DNA binding by the Meis1 homeodomain proteins.

Recent studies show that Hox homeodomain proteins from paralog groups 1 to 10 gain DNA binding specificity and affinity through cooperative binding with the divergent homeodomain protein Pbx1. However, the AbdB-like Hox proteins from paralogs 11, 12, and 13 do not interact with Pbx1a, raising the possibility of different protein partners. The Meis1 homeobox gene has 44% identity to Pbx within the homeodomain and was identified as a common site of viral integration in myeloid leukemias arising in BXH-2 mice. These integrations result in constitutive activation of Meis1. Furthermore, the Hoxa-9 gene is frequently activated by viral integration in the same BXH-2 leukemias, suggesting a biological synergy between these two distinct classes of homeodomain proteins in causing malignant transformation. We now show that the Hoxa-9 protein physically interacts with Meis1 proteins by forming heterodimeric binding complexes on a DNA target containing a Meis1 site (TGACAG) and an AbdB-like Hox site (TTTTACGAC). Hox proteins from the other AbdB-like paralogs, Hoxa-10, Hoxa-11, Hoxd-12, and Hoxb-13, also form DNA binding complexes with Meis1b, while Hox proteins from other paralogs do not appear to interact with Meis1 proteins. DNA binding complexes formed by Meis1 with Hox proteins dissociate much more slowly than DNA complexes with Meis1 alone, suggesting that Hox proteins stabilize the interactions of Meis1 proteins with their DNA targets.

Methylthioadenosine phosphorylase deficiency in human leukemias and solid tumors.

5'-Methylthioadenosine (MTA) is a naturally occurring nucleoside which is degraded by MTA phosphorylase (MTAase) to adenine and methylthioribose-1-phosphate in all normal mammalian cells. These products of the phosphorylytic cleavage of MTA are recycled to the nucleotide pool and methionine, respectively. Thus, supplemental MTA could theoretically be utilized by MTAase-containing cells as a source of methionine and adenine. In fact, in vitro experiments have shown that MTAase-containing cells proliferate normally in methionine-free medium if MTA is added to the cultures (M. K. Riscoe and A. J. Ferro, J. Biol. Chem., 259: 5465-5471, 1984). In contrast, MTAase-deficient malignant cell lines do not proliferate under these conditions. In light of these observations and the recent demonstration (N. Kamatani et al., Blood, 60: 1387-1391, 1982) that a proportion of acute lymphoblastic leukemias lack MTAase, we wished to determine if this enzyme deficiency occurs in a variety of human neoplasms. Accordingly, malignant cells from eight patients with acute nonlymphocytic leukemia and ten patients with various solid tumors were assayed for MTAase activity. Samples from one of the eight acute nonlymphocytic leukemia patients and three of the 10 solid tumor patients (one with melanoma, one with squamous cell lung cancer, and one with adenocarcinoma of the rectum) had undetectable MTAase activity. In contrast, erythrocytes, neutrophils, and monocytes isolated from normal subjects and from patients with immunodeficiency syndromes or cancer all contained enzyme activity. In addition, the methods of preservation, storage, and cell disruption did not affect MTAase activity. These observations confirm and extend the findings of Kamatani et al. (Blood, 60: 1387-1391, 1982) by demonstrating that MTAase deficiency occurs in a variety of human malignancies including acute nonlymphocytic leukemia and solid tumors. This metabolic difference between normal and malignant cells may be therapeutically exploitable.

Enhancement of the clinical activity of melphalan by the hypoxic cell sensitizer misonidazole.

One hundred patients with non-small cell lung cancer were entered by members of the Northern California Oncology Group into a randomized Phase II trial of i.v. melphalan versus i.v. melphalan with concomitant oral misonidazole. The patients had not received prior chemotherapy. Eighty-five patients were evaluable for assessment of response and 89 were evaluable for toxicity analysis. The melphalan/misonidazole group had a superior response rate (two complete and four partial responses among 42 patients or 14%) compared to the melphalan group in which there were no responses among 43 patients (p = 0.024, two-sided Fisher exact test). Since hematological toxicity was equivalent in the two groups, there was an improvement in therapeutic index. Data from 12 patients undergoing pharmacological studies demonstrated that the plasma concentration of melphalan was 25% higher in the misonidazole group, a difference that is not statistically significant. Although the mechanism of interaction has not been fully established, this randomized trial demonstrates that a chemosensitizer can enhance the clinical antitumor activity of an alkylating agent and suggests that chemosensitizers in combination with alkylating agents should be investigated in further clinical trials.

High-dose cisplatin in hypertonic saline: reduced toxicity of a modified dose schedule and correlation with plasma pharmacokinetics. A Northern California Oncology Group Pilot Study in non-small-cell lung cancer.

Although increased efficacy has been described with a five-day schedule of high-dose cisplatin (CDDP) in hypertonic saline, severe myelosuppression and cumulative neurotoxicity have limited the usefulness of this therapy. In order to evaluate a possible dose-response relationship in non-small-cell lung cancer (NSCLC), 17 patients with metastatic disease were treated with a modified dose schedule delivering the same total dose (200 mg/m2) in a divided day 1 and 8 schedule. During a pilot study, a total of 47 cycles of therapy were administered, with a median of three cycles per patient and a median total cumulative dose of 600 mg/m2. Nine of 17 patients received at least 600 mg/m2. While nephrotoxicity was similar to previous reports of the five-day schedule, the incidence and severity of myelosuppression and peripheral neuropathy were markedly reduced. Using this modified schedule, severe myelosuppression did not occur. Clinically severe peripheral neuropathy developed in only one patient (6%). The overall response rate was 47% (eight of 17 patients). Plasma platinum pharmacokinetics during five cycles of the modified day 1 and 8 schedule were compared with pharmacokinetics of the five-day schedule. Accumulation of plasma ultrafiltrate platinum occurred in the five-day schedule, but not in the day 1 and 8 schedule. This difference in pharmacokinetics is one possible explanation for the reduced toxicity of this modified schedule. Although the degree of activity seen in this pilot study is encouraging, the efficacy of high-dose CDDP in NSCLC remains to be defined. In view of reduced myelosuppression and neurotoxicity, further trials with this modified schedule are indicated.

Frequent co-expression of the HOXA9 and MEIS1 homeobox genes in human myeloid leukemias.

There is increasing evidence that HOX homeobox genes play a role in leukemogenesis. Recent studies have demonstrated that enforced co-expression of HOXA9 and MEIS1 in murine marrow leads to rapid development of myeloid leukemia, and that these proteins exhibit cooperative DNA binding. However, it is unclear whether co-activation of HOXA9 and MEIS genes is a common occurrence in human leukemias. We surveyed expression of HOXA9 and MEIS1 in 24 leukemic cell lines and 80 patient samples, using RNase protection analyses and immunohistochemistry. We demonstrate that the expression of HOXA9 and MEIS1 in leukemia cells is uniquely myeloid, and that these genes are commonly co-expressed in myeloid cell lines and in samples of acute myelogenous leukemia (AML) of all subtypes except in promyelocytic leukemia. While HOXA9 is expressed in most cases of chronic myelogenous leukemia, MEIS1 is weakly expressed or not at all. Immunohistochemical staining of selected AML samples showed moderate to high levels of HOXA9 protein, primarily cytoplasmic, in leukemic myeloblasts, with weaker and primarily nuclear staining for MEIS1. These data support the concept that co-activation of HOXA9 and MEIS1 is a common event in AML, and may represent a common pathway of many different oncogenic mutations.

Stage- and lineage-specific expression of the HOXA10 homeobox gene in normal and leukemic hematopoietic cells.

There is growing evidence that the HOX homeobox-containing transcription factors are differentially expressed during hematopoiesis. We have previously demonstrated that the HOXA10 gene is expressed in unfractionated normal marrow and in immortalized leukemic cell lines with myelomonocytic features, but not in cell lines with lymphoid or erythroid features. To gain insights into the patterns of activation of this gene during hematopoietic differentiation, we have examined HOXA10 expression in CD34+ and CD34- subfractions of normal marrow and normal peripheral blood, as well as samples from patients with a variety of acute and chronic leukemias. HOXA10 is strongly expressed in CD34+ normal marrow cells, markedly downregulated in CD34- marrow cells, and inactive in mature neutrophils, monocytes, and lymphocytes. HOXA10 is expressed in all types of acute myelogenous leukemia (AML) with the notable exception of acute promyelocytic leukemia (AML-M3). HOXA10 message is observed in chronic myelogenous leukemia (CML) but appears to be reduced in accelerated phase and blast crisis, particularly lymphoid blast crisis. With rare exception, HOXA10 expression is not observed in samples of acute or chronic lymphoid leukemias. Normal marrow and patient samples appear to contain a single transcript which encodes a full-length homeobox-containing protein, while immortalized cell lines contain an additional alternatively spliced transcript. These studies indicate that HOXA10 expression is restricted to early stages of myeloid differentiation.

Expression of class I homeobox genes in fetal and adult murine skin.

We examined the expression patterns of several class I homeobox genes in mouse fetal and adult skin. All the genes of the Hox-B locus, except Hoxb-1, are expressed in skin from murine fetuses of 17 and 18 d gestation, at which time the epidermis is undergoing stratification and differentiation. The amount of individual Hox gene message varies considerably, but expression of all genes is detectable by RNase protection except Hoxb-1, which could not be detected even by the reverse transcription-polymerase chain reaction (RT-PCR) assay. Homeobox gene expression in skin is not confined to the Hox-B locus; the paralogous genes Hoxa-4, -b-4, -c-4, and -d-4 are all expressed. The amount of Hoxb-4, -b-2, and -c-4 message in skin is relatively constant from the earliest gestational day examined (day 16) through birth at day 19. Expression of several homeobox genes is also seen in adult skin.

HOX homeobox genes exhibit spatial and temporal changes in expression during human skin development.

The spatial and temporal deployment of HOX homeobox genes along the spinal axis and in limb buds during fetal development is a key program in embryonic pattern formation. Although we have previously reported that several of the HOX homeobox genes are expressed during murine skin development, there is no information about developmental expression of HOX genes in human skin. We have now used reverse transcriptase polymerase chain reaction, in conjunction with a set of degenerate oligonucleotide primers, to identify a subset of HOX genes that are expressed during human fetal skin development. In situ hybridization analyses demonstrated that there were temporal and spatial shifts in expression of these genes. Strong HOXA4 expression was detected in the basal cell layers of 10 wk fetal epidermis and throughout the epidermis and dermis of 17 wk skin, whereas weak signal was present in the granular layer of newborn and adult skin. The expression patterns of HOXA5 and HOXA7 were similar, but their expression was weaker. In situ hybridization analysis also revealed strong HOXC4 and weaker HOXB7 expression throughout fetal development, whereas HOXB4 was expressed at barely detectable levels. Differential HOX gene expression was also observed in developing hair follicles, and sebaceous and sweat glands. None of the HOX genes examined were detected in the adult dermis.

Autoimmune thrombocytopenia in sarcoidosis.

Severe thrombocytopenia and splenomegaly developed in a young man with sarcoidosis. Platelet-associated immunoglobulin (IgG) was strongly positive, and platelet survival studies revealed a half-life of five and a half hours. Treatment with prednisone and vincristine led to a rise in the platelet count to 100,000/mm3 after two months with no change in the splenomegaly. Five months later, when the platelet count was normal, the level of platelet-associated IgG had fallen to normal. Repeated platelet survival studies showed an initial half-life of three hours with a second half-life of two days, associated with accumulation in the spleen. Although there was evidence for splenic sequestration of platelets, the dominant mechanism of thrombocytopenia appeared to be antibody-mediated destruction, analogous to that seen in idiopathic autoimmune thrombocytopenic purpura and responsive to immunosuppressive therapy.

Erythrophagocytic T-cell lymphoma: immunologic and cytogenetic evidence for a clonal malignancy of the CD8-positive T-cell subclass.

We report a case of an erythrophagocytic T-cell lymphoma with autoimmune hemolytic anemia, osteolytic lesions, hypercalcemia, hepatomegaly, and marrow invasion without evident lymph node, skin or peripheral blood involvement. The malignant cells were large immunoblastic cells with pleomorphic nuclei and occasional phagocytic vacuoles containing erythrocytes. Immunologic studies showed the tumor cells to have the phenotype of activated T-cells of the cytotoxic/suppressor subclass (HLA- Dr-positive, CD8 positive) with surface receptors for IgG Fc but lacking functional activity in assays of natural killer activity and antibody-dependent cytotoxicity. The tumor cells appeared to express receptors for T-cell growth factor (Tac). Cytogenetic study of marrow mononuclear cells revealed complex but non-random karyotypic abnormalities (45 XX, +11, -12, -16, 17 p+). The clinical and laboratory features indicate that erythrophagocytic T-cell lymphoma represents a true clonal malignancy of the CD8-positive subclass of T-lymphocytes.

Topical dimethylsulfoxide may prevent tissue damage from anthracycline extravasation.

The optimal management of anthracycline extravasation remains unclear. Traditional topical measures to reduce local tissue damage, including corticosteroids, sodium bicarbonate, and ice applications, have not consistently demonstrated beneficial effects. This report describes our experience with four adult patients who suffered anthracycline extravasation and were treated with a regimen of ice, local glucocorticoid injection, and dimethylsulfoxide (DMSO) 55%-99% applied topically every 2-4 h after extravasation for a minimum of 3 days. In all four cases, pain and erythema resolved within 2 days; in no case did tissue necrosis or skin ulceration occur. Topical DMSO is a safe, inexpensive agent that appears to reduce the risk of anthracycline-induced tissue damage. Further studies are needed to determine the optimal dose and schedule of DMSO application and to assess its efficacy in extravasation injuries from other vesicants.

Metastatic cancer with unknown primary.

Close cooperation between an experienced pathologist and oncologist is essential in the management of patients with unknown primary carcinoma. A comprehensive pathological examination is crucial and, with undifferentiated tumors, this will include immunohistology and/or electron microscopy. Ample properly processed tissue therefore must be provided. Time-consuming and costly radiographic and imaging studies should be avoided. No matter how extensive the evaluation, in a majority of cases, the primary site will never be found, so a selective search for treatable tumors is most appropriate and cost-effective. With adenocarcinomas, this will include prostate, breast, and ovary; for undifferentiated tumors, small cell bronchogenic carcinoma, lymphomas, and germ cell tumors. Table 4 summarizes recommended studies for diagnosing unknown primary undifferentiated or adenocarcinomas. Women with adenocarcinoma in axillary nodes without a primary site should be treated as having breast cancer. Estrogen and progesterone receptor assays are to be obtained on the axillary biopsy. High and midcervical nodes with metastatic squamous cell carcinoma can be treated effectively and, not infrequently, cured with surgery and radiation therapy, even if the primary site never is detected. If doubt remains, treatment should be selected that offers the best chance of significant palliation or cure--for example, cisplatin-based chemotherapy in possible extragonadal germ cell tumors.

Evaluation of cisplatin dose intensity: current status and future prospects.

Cisplatin dose intensity is a potentially important concept in the chemotherapeutic management of several human malignancies. In vitro studies have demonstrated steep dose-response relationships in a variety of tumor types. Although previous clinical trials have also suggested the importance of cisplatin dose, renal insufficiency has limited exploration of more dose-intensive regimens. Recently, therapeutic strategies such as hypertonic saline have allowed dose escalation to the level of 200 mg/m2/28 day cycle, or 50 mg/m2/week as standardized for dose intensity analysis. In this review, we summarize the rationale for investigation of cisplatin dose intensity, pertinent pharmacokinetics, and potential methods of dose escalation. Clinical data are presented regarding both efficacy and newly recognized non-renal toxicities of high-dose cisplatin. We describe the results of a pharmacokinetically designed schedule of high-dose cisplatin in hypertonic saline, administering a divided dose of 100 mg/m2 on days 1 and 8 of each 28-day cycle. This regimen has resulted in high response rates and encouraging survival times in non-small cell lung cancer, and is currently being investigated in several different tumor types. Compared to other dose-intensive regimens, this day 1 and 8 schedule is relatively well-tolerated, with a toxicity pattern not substantially different from standard-dose cisplatin. Since non-renal toxicities such as peripheral neuropathy continue to limit cumulative cisplatin dose, other methods of increasing dose intensity are of considerable interest. We present the rationale and current trials utilizing chemoprotective or "rescue" agents as a means of maximizing cisplatin dose intensity and minimizing the toxicity of this agent.

Expression of homeobox genes in human erythroleukemia cells.

Because homeobox-containing genes play a major role in embryogenesis and tissue identity in Drosophila and because similar genes encode tissue-specific transcription factors in mammalian cells, we hypothesized that homeobox genes might plan a role in hematopoietic differentiation and lineage commitment. We therefore surveyed a number of human leukemic cell lines for expression of homeobox-containing genes by Northern gel analysis with probes from the Hox 2 cluster of homeobox genes on chromosome 17. We observed transcripts for Hox 2.1, 2.2, 2.3 and 2.6 in the erythroid line HEL and for Hox 2.3 and 2.6 in the erythroid line K562. Using homeobox-specific probes we confirmed that the transcripts visualized contained the homeodomains for each gene as well as the flanking sequences. The myeloid lines HL60, KG1 and U937 did not express specific transcripts for any of the 4 genes studied. However, all these cell lines demonstrated bands when probed at low stringency with certain Hox 2 probes, indicating the expression of other homologous but as yet unidentified homeobox genes. Expression of Hox 2.3 and 2.6 was seen in some T and B lymphoid cell lines. Induction of differentiation in HEL cells resulted in complex modulation of expression of the Hox 2 genes. We have therefore observed erythroid-restricted expression of certain Hox 2 homeobox containing genes in human erythroid cell lines and modulation of that expression with differentiation, suggesting a role for these genes in the regulation of hematopoiesis. Different homeobox genes appear to be expressed in non-erythroid leukemic cell lines.

Unilateral adrenalectomy as a treatment for adrenocortical tumors in ferrets: five cases (1990-1992).

Adrenocortical tumors were diagnosed in 5 adult spayed ferrets. Four ferrets had bilaterally symmetrical alopecia of the caudal femoral region, abdomen, and tail, and 1 had alopecia of the distal limbs and feet. All 5 ferrets had vulvar swelling. During abdominal ultrasonography, irregular masses, believed to involve the adrenal glands, were seen in all 5 ferrets. Unilateral adrenalectomy was performed successfully in each ferret by use of ventral midline celiotomy. On histologic examination of biopsy samples, 4 ferrets were found to have adrenocortical adenomas, and 1 ferret was found to have an adrenocortical adenocarcinoma. All clinical signs resolved after adrenalectomy, suggesting that the adrenocortical tumors had been secreting adrenocortical hormones.

Evaluation of urinary cortisol:creatinine ratios for the diagnosis of hyperadrenocorticism associated with adrenal gland tumors in ferrets.

Assays were validated for the measurement of urinary concentrations of cortisol and creatinine in domestic ferrets (Mustela putorius furo). Urinary concentrations of cortisol and creatinine and the calculated urinary cortisol:creatinine ratio (UCCR) values were determined for 29 clinically normal female ferrets, 22 clinically normal male ferrets, and 12 ferrets with adrenal gland tumors. The UCCR values for the 51 clinically normal ferrets ranged from 0.04 x 10(-6) to 1.66 x 10(-6), with a median value of 0.22 x 10(-6). The UCCR values were significantly (P < or = 0.01) higher in the 12 ferrets with adrenal tumors, with a range of 0.5 x 10(-6) to 60.13 x 10(-6) and a median of 5.98 x 10(-6). We concluded that determination of UCCR values was useful in the diagnosis of hyperadrenocorticism associated with adrenal neoplasia in domestic ferrets.