Protein expression and gene copy number changes of receptor tyrosine kinase in thymomas and thymic carcinomas.

BACKGROUND: Insulin-like growth factor-1 receptor (IGF-1R), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-type 2 (HER2), and c-Met are members of the receptor tyrosine kinases (RTKs). The associations between the RTK status [protein expression and gene copy number (GCN)] and patient characteristics and between the RTK status and prognosis remain undetermined. MATERIALS AND METHODS: The study included 140 patients who underwent surgery for thymic tumors. Protein expression was evaluated by immunohistochemistry (IHC) and GCN was evaluated by bright-field in situ hybridization (BISH). The correlations between the RTK status and clinicopathological findings were examined. RESULTS: IGF-1R protein was frequently detected in thymic carcinoma (83.8%) and EGFR in thymic tumors (91.4%). Thirty-six and 39 tumors were BISH high for IGF-1R and EGFR, respectively: 28 and 25 exhibited high polysomy; 8 and 14 exhibited gene amplification. No tumor was positive for HER2 or c-Met by IHC and BISH. Multivariate analysis revealed that IGF-1R gene amplification (P = 0.027), thymic carcinoma histology, and higher tumor stage were significantly correlated with an adverse prognosis. CONCLUSIONS: Thymic epithelial tumors frequently express IGF-1R and/or EGFR proteins. IGF-1R gene amplification is suggested to define an unfavorable subset for thymic epithelial tumors.

HLA-DR (Ia) immune phenotype predicts outcome for patients with diffuse large cell lymphoma.

The clinical utility for establishing the immune phenotype in patients with non-Hodgkin's lymphoma is controversial. To help resolve this dilemma, we studied 104 consecutive patients with diffuse large cell lymphoma, the most common subtype of potentially curable non-Hodgkin's lymphomas. The presence or absence of the human class II histocompatibility antigen was determined using the monoclonal antibody anti-HLA-DR (Ia), and the results correlated with pretreatment clinical features and survival. We found that eight HLA-DR negative patients had similar pretreatment clinical characteristics compared with 96 HLA-DR positive patients, but HLA-DR negative patients had a significantly shorter survival duration compared with HLA-DR positive patients (P = 0.003 log-rank). The median survival of the HLA-DR negative patients was 0.5 years compared to 2.8 yr for the HLA-DR positive patients. No HLA-DR negative patient survived beyond 1.5 yr. A multi-variate analysis, adjusting for prognostic factors of known clinical significance, confirmed the importance of HLA-DR as a prognostic factor (P = 0.016). We conclude that determining the presence of HLA-DR is a relatively simple pretreatment study that identifies a small but important group of patients who are not curable using currently available combination chemotherapy.

P-glycoprotein expression: critical determinant in the response to osteosarcoma chemotherapy.

BACKGROUND: Fewer than 20% of patients with bone cancer who are treated with surgery alone are cured. Even with the best current treatment, surgery combined with chemotherapy, only 60%-80% of patients with nonmetastatic bone cancer and 10% of patients with metastatic bone cancer are cured. Thus far, the reason for treatment failure in the nonresponding subset has not been identified. It has been hypothesized that P-glycoprotein, which confers multidrug resistance, might be the cause. We sought to determine whether the expression of P-glycoprotein is associated with poor treatment outcome in osteosarcoma. METHODS: In a retrospective study, we correlated P-glycoprotein expression with the outcome of conventional chemotherapy in 62 consecutive, clinically staged patients diagnosed as having osteosarcoma between 1980 and 1989. RESULTS: P-glycoprotein was overexpressed in 27 patients but not in another 34 patients, and expression was ambiguous in the sample from one patient. At a median follow-up of 8.9 years, the 34 patients whose tumors did not express P-glycoprotein had significantly better relapse-free rates than the 27 subjects whose tumors expressed the protein (87% versus 0%; P<.00001) and had improved survival rates (94% versus 35%; P<.00001). Among the 46 patients who received chemotherapy before surgery, the 23 whose tumors were negative for P-glycoprotein showed significantly better long-term outcomes (P<.00002), although differences in tumor necrosis in response to therapy were only of borderline significance (P = .057). CONCLUSIONS: P-glycoprotein expression does correlate with treatment failure in patients with osteosarcoma. This correlation raises the possibility that inhibiting the action of P-glycoprotein as part of therapy for this disease would improve outcome.

Prediction of doxorubicin resistance in vitro in myeloma, lymphoma, and breast cancer by P-glycoprotein staining.

Prior studies have shown that the P-glycoprotein is a cell membrane efflux pump that is quantitatively increased in expression in multidrug-resistant tumor cell lines. In this study, fresh tumor tissues from patients with multiple myeloma, malignant lymphoma, or metastatic breast cancer were studied immunohistochemically for P-glycoprotein expression and for in vitro sensitivity to doxorubicin. Twenty-six patients who were either previously untreated or in relapse after chemotherapy had tumor specimens submitted that could be evaluated in both assays. The testing was done independently and blindly in separate laboratories instead of our being provided relevant clinical data on the patients. Tumor cells from 12 of the 26 patients (46%) stained positively for P-glycoprotein. Fifteen of the 26 specimens (58%) exhibited drug resistance in vitro. Although only three (21%) of the 14 P-glycoprotein-negative tumors exhibited in vitro resistance to doxorubicin, all 12 fresh tumors that stained positively for P-glycoprotein were resistant to doxorubicin. The difference in frequency of intrinsic doxorubicin resistance between P-glycoprotein-negative and -positive tumors was highly significant (P less than .001). Similar trends were observed in each of the individual tumor categories and were statistically significant in myeloma and breast cancer. Four of the biopsy specimens that stained positively for P-glycoprotein and exhibited doxorubicin resistance were from patients who had not received prior cytotoxic chemotherapy. Similar conclusions were reached when results of drug sensitivity tests were ranked in relation to the median infective dose rather than by criteria based on correlations with clinical drug resistance. Our findings indicate that positive staining for P-glycoprotein associated with multidrug resistance predicts intrinsic cellular resistance of human cancers to doxorubicin. We anticipate that immunohistochemical staining for P-glycoprotein will prove useful in clinical oncology.

Expression of vascular endothelial growth factor and its receptors in hematopoietic malignancies.

Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis by acting as a potent inducer of vascular permeability as well as serving as a specific endothelial cell mitogen. The importance of angiogenic factors such as VEGF, although clearly established in solid tumors, has not been fully elucidated in human hematopoietic neoplasms. We examined the expression of mRNA and protein for VEGF in 12 human hematopoietic tumor cell lines, representing multiple lineages and diseases, including leukemia, lymphoma, and multiple myeloma. Our results revealed that VEGF message was expressed in these cells and that the corresponding protein was secreted into the extracellular environment. Five of the 12 cell lines were also found to express the Flt-1 receptor for VEGF at a moderate to strong level, suggesting an autocrine pathway. When human vascular endothelial cells were exposed to recombinant human VEGF, there was an increase in the mRNA for several hematopoietic growth factors including macrophage colony-stimulating factor, granulocyte colony-stimulating factor and interleukin 6. Plasma cells in the bone marrow from patients diagnosed with multiple myeloma were found to express VEGF, whereas both the Flt-1 and KDR high affinity VEGF receptors were observed to be markedly elevated in the normal bone marrow myeloid and monocytic cells surrounding the tumor. These data raise the possibility that VEGF may play a role in the growth of hematopoietic neoplasms such as multiple myeloma through either a paracrine or an autocrine mechanism.

Development and characterization of a melphalan-resistant human multiple myeloma cell line.

We present data describing a human myeloma cell line (8226/LR-5) selected for resistance to melphalan which exhibits a 7-fold level of resistance to melphalan and is partially cross-resistant to other bifunctional alkylators and X-irradiation. Melphalan resistance is relatively unstable with a decrease in resistance observed within 17 weeks in the absence of drug. The resistance observed in this cell line is not mediated by reduced intracellular melphalan accumulation. DNA interstrand cross-linking at equivalent intracellular drug accumulation is significantly reduced in the resistant subline. Whether this reduction is the result of a decrease in the formation of this lesion or to an increased rate of removal of the lesion remains to be determined. Growth characteristics and cell cycle kinetics, including S phase, were similar between sensitive and resistant cell lines. Intracellular nonprotein thiols were found to be significantly elevated in the resistant 8226/LR-5 cells; as cells revert or lose resistance, intracellular nonprotein sulfhydryl levels decline. Prior treatment of the cells with buthionine sulfoximine significantly reduced nonprotein sulfhydryl levels and enhanced melphalan cytotoxicity in both the sensitive and resistant cell lines. Thiols appear to play a role in mediating melphalan resistance.

Expression of the metalloproteinase matrilysin in DU-145 cells increases their invasive potential in severe combined immunodeficient mice.

Human prostate cancer displays a high degree of variability in its rate of spread, which could be due largely to differences in the invasive potential of the tumor cells. The degradation of the basal lamina and stromal extracellular matrix is mediated in part by the secretion of matrix metalloproteinases (MMPs). Matrilysin (PUMP-1, MMP-7) and gelatinase A (M(r) 72,000 type IV collagenase, MMP-2) have been shown to be overexpressed in prostate carcinoma. We have expressed the single MMP matrilysin in the tumorigenic but nonmetastatic human prostate tumor cell line DU-145 to determine if matrilysin has a functional role in prostate tumor cell invasion. DU-145 cells expressing matrilysin were significantly more invasive than vector-only transfected cell lines as assayed by a severe combined immunodeficient mouse model of tumor cell invasion. Vector-only transfected DU-145 cells injected i.p. into severe combined immunodeficient mice invaded the diaphragm in only 1 of 9 mice (11%), whereas matrilysin-transfected DU-145 cells invaded the diaphragm in 12 of 18 mice (66%). The difference between the controls and matrilysin-transfected cells was statistically significant (P < 0.006). These results suggest a functional role for matrilysin in the initial invasion of prostate cancer through the epithelial basal lamina and into the surrounding stroma.

Multidrug resistance protein (MRP) expression in retinoblastoma correlates with the rare failure of chemotherapy despite cyclosporine for reversal of P-glycoprotein.

Failure of chemotherapy associated with expression of the multidrug resistance protein p170 frequently occurs in retinoblastoma (RB). Despite using cyclosporine, which inhibits p170 and improves our chemotherapy results, rare failures occur. In nonmetastatic primarily enucleated RBs, we show expression of p170 in 3 of 18 samples and expression of multidrug resistance protein (MRP), the second protein associated with resistance to chemotherapy, in 1 of 18 samples. All three RBs that failed chemotherapy without cyclosporine expressed MRP with p170. All three RBs that were enucleated immediately when chemotherapy failed despite the addition of cyclosporine expressed only MRP. One RB enucleated 2 years after failing chemotherapy with cyclosporine, despite radiation and salvage chemotherapy, expressed both p170 and MRP. Two metastatic RBs that expressed both p170 and MRP at diagnosis and at recurrence failed chemotherapy without cyclosporine, whereas one metastatic RB that expressed neither protein was cured by chemotherapy without cyclosporine. MRP may result in failure of chemotherapy despite the elimination of p170-expressing clones by cyclosporine.

Relationship of the expression of the multidrug resistance gene product (P-glycoprotein) in human colon carcinoma to local tumor aggressiveness and lymph node metastasis.

P-glycoprotein mediates classic multidrug resistance by functioning as an efflux pump that excretes lipophilic chemotherapeutic drugs from cancer cells. We now report an association of P-glycoprotein in colon carcinomas with another tumor property, i.e., enhancement of local tumor aggressiveness. P-glycoprotein was detected with monoclonal antibody immunohistochemistry in 65 of 95 primary colon adenocarcinomas, which were stage B1 or greater. In all but 1 of the 95 cases, solitary invading carcinoma cells were present at the leading edge of the tumor. This subpopulation of invasive carcinoma cells expressed P-glycoprotein (P-Gp+) in 47 of the 95 surgically resected colon specimens. Cases were grouped on the basis of the presence (Group 1, 47 cases) or absence (Group 2, 48 cases) of P-Gp+ invasive carcinoma cells. There was a significantly greater incidence of vessel invasion (P less than 0.001) and lymph node metastases (P less than 0.01) in Group 1 cases. Groups 1 and 2 did not differ with respect to tumor size, depth of invasion of the bowel wall, histological grade, maximum tumor size, mitotic index, mucin production, or presence of perineural invasion (P greater than 0.1). Our findings indicate that P-Gp+ invasive colon cancer cells may have an increased potential for dissemination, suggesting that P-glycoprotein may influence cell behavior.

Methods to detect P-glycoprotein-associated multidrug resistance in patients' tumors: consensus recommendations.

Multidrug resistance (MDR), especially that associated with overexpression of MDR1 and its product, P-glycoprotein (Pgp), is thought to play a role in the outcome of therapy for some human tumors; however, a consensus conclusion has been difficult to reach, owing to the variable results published by different laboratories. Many factors appear to influence the detection of Pgp in clinical specimens, including its low and heterogeneous expression; conflicting definitions of detection end points; differences in methods of sample preparation, fixation, and analysis; use of immunological reagents with variable Pgp specificity and avidity and with different recognition epitopes; use of secondary reagents and chromogens; and differences in clinical end points. Also, mechanisms other than Pgp overexpression may contribute to clinical MDR. The combined effect of these factors is clearly important, especially among tumors with low expression of Pgp. Thus, a workshop was organized in Memphis, Tennessee, to promote the standardization of approaches to MDR1 and Pgp detection in clinical specimens. The 15 North American and European institutions that agreed to participate conducted three preworkshop trials with well-characterized MDR myeloma and carcinoma cell lines that expressed increasing amounts of Pgp. The intent was to establish standard materials and methods for a fourth trial, assays of Pgp and MDR1 in clinical specimens. The general conclusions emerging from these efforts led to a number of recommendations for future studies: (a) although detection of Pgp and MDR1 is at present likely to be more reliable in leukemias and lymphomas than in solid tumors, accurate measurement of low levels of Pgp expression under most conditions remains an elusive goal; (b) tissue-specific controls, antibody controls, and standardized MDR cell lines are essential for calibrating any detection method and for subsequent analyses of clinical samples; (c) use of two or more vendor-standardized anti-Pgp antibody reagents that recognize different epitopes improves the reliability of immunological detection of Pgp; (d) sample fixation and antigen preservation must be carefully controlled; (e) multiparameter analysis is useful in clinical assays of MDR1/Pgp expression; (f) immunostaining data are best reported as staining intensity and the percentage of positive cells; and (g) arbitrary minimal cutoff points for analysis compromise the reliability of conclusions. The recommendations made by workshop participants should enhance the quality of research on the role of Pgp in clinical MDR development and provide a paradigm for investigations of other drug resistance-associated proteins.

Combination chemotherapy, glucocorticoids, and interferon alfa in the treatment of multiple myeloma: a Southwest Oncology Group study.

PURPOSE: Standard therapy for multiple myeloma consists of cytotoxic chemotherapy plus glucocorticoids. Interferon (IFN) alfa maintenance is reported to prolong chemotherapy-induced remissions and survival. This study evaluates induction chemotherapy, glucocorticoids, and interferon maintenance in myeloma. PATIENTS AND METHODS: Five hundred twenty-two previously untreated myeloma patients were randomized to three chemotherapy regimens with differing glucocorticoid intensities. Patients who achieved remission were randomized to receive IFN or observation until relapse. Patients who failed to respond to chemotherapy received IFN alfa plus dexamethasone (DEX). RESULTS: Five hundred nine patients were eligible for induction chemotherapy. Chemotherapy with higher dose-intensity glucocorticoids yielded higher response rates and improved survival (P = .02 for the three-group comparison; P < .05 for each higher glucocorticoid arm v vincristine, melphalan, cyclophosphamide, and prednisone alternating with vincristine, carmustine [BCNU], doxorubicin, and prednisone [VMCP/VBAP]). One hundred ninety-three patients who achieved remission were randomized to receive IFN alfa 3 MU three times weekly or observation. IFN was not superior to observation for relapse-free (P = .95) or overall survival (P = .39) from start of maintenance. Eighty-eight induction failures received 5 MU of IFN three times weekly plus DEX. Patients who received IFN/DEX had a median survival duration of 48 months from start of IFN/DEX. CONCLUSION: Higher-dose glucocorticoids increases frequency of response to chemotherapy and prolong survival in myeloma. IFN maintenance with the dose schedule used in this trial did not prolong relapse-free or overall survival. We cannot exclude a small effect of IFN, as most individual trials do not have sufficient statistical power. Meta-analysis of randomized trials evaluating IFN maintenance in myeloma might be of value. While IFN appeared ineffective, addition of higher-dose glucocorticoids improved outcome in myeloma.

P-glycoprotein expression in malignant lymphoma and reversal of clinical drug resistance with chemotherapy plus high-dose verapamil.

P-glycoprotein is a transmembrane protein thought to function as an efflux pump to detoxify cells. It is associated with multidrug resistance in laboratory systems and has recently been found in human tumors associated with in vitro and clinical drug resistance. We used an immunohistochemical method employing two monoclonal antibodies, JSB-1 and C-219, to detect expression of P-glycoprotein in lymphoma patients. One of 42 newly diagnosed and untreated lymphoma patients (2%) and seven of 11 previously treated and drug-resistant patients (64%) had detectable levels of P-glycoprotein (P less than .001). Based on prior reports suggesting that verapamil sensitizes drug-resistant cancer cells to chemotherapy by competitive inhibition of the P-glycoprotein, we tested the efficacy of verapamil as a chemosensitizer in 18 patients with drug-refractory disease. All patients had previously failed or relapsed within 3 months of a doxorubicin-vincristine-containing drug regimen. Patients received day-1 cyclophosphamide, and 4-day continuous infusion doxorubicin and vincristine and oral dexamethasone (CVAD). CVAD was combined with 5-day continuous infusion verapamil given at maximally tolerated dose. Overall, 13 of 18 patients (72%) responded to treatment including five complete remissions (CRs; 28%). The median duration of response was 200 days and median survival was 242 days. The dose-limiting toxicity of the verapamil infusion was temporary cardiac dysfunction including hypotension, congestive heart failure, and cardiac arrhythmia. We conclude that the P-glycoprotein is uncommonly expressed in untreated lymphomas and frequently expressed in clinically drug-resistant disease, and that chemotherapy using CVAD plus maximally tolerated doses of verapamil results in a high response rate in patients carefully selected for clinical drug resistance.

Phase II study of paclitaxel and valspodar (PSC 833) in refractory ovarian carcinoma: a gynecologic oncology group study.

PURPOSE: A phase II study was conducted to determine the efficacy of paclitaxel and valspodar (PSC 833) in patients with advanced epithelial ovarian cancer. Valspodar, a nonimmunosuppressive cyclosporine D analogue that reverses P-glycoprotein-mediated multidrug resistance, in combination with paclitaxel might be active in paclitaxel-resistant and refractory ovarian cancer. PATIENTS AND METHODS: Patients received valspodar 5 mg/kg orally qid x 12 doses. Paclitaxel (70 mg/m(2) intravenously for 3 hours) was administered on day 2, 2 hours after the fifth or sixth dose of valspodar. This treatment was repeated every 21 days. One blood sample was collected before the sixth dose of valspodar for the first three cycles to evaluate valspodar trough concentration. Tumor tissue was obtained from patients for immunohistochemical staining of P-glycoprotein. RESULTS: Of 60 patients entered, 58 were assessable for response. There were five partial responses (8.6%; 90% confidence interval [CI], 3.8 to 20.0; median duration of response, 5.0 months [range, 1.9 to 10.5 months]). Median progression-free survival was 1.5 months (90% CI, 1.4 to 2.4). Grade 3 or 4 toxicities observed were neutropenia, anemia, nausea and vomiting, peripheral neuropathy, and cerebellar ataxia. The trough concentrations of valspodar were > or = 1,000 ng/mL in all but two of 40 patients in the first cycle. Immunohistochemical staining for P-glycoprotein was positive for one of two responding patients. CONCLUSION: Valspodar in combination with paclitaxel has limited activity in patients with paclitaxel-resistant ovarian carcinoma. An international randomized clinical trial of paclitaxel and carboplatin with or without valspodar as first-line therapy in advanced ovarian cancer is underway.

Discrepancies in clinical laboratory testing of eligibility for trastuzumab therapy: apparent immunohistochemical false-positives do not get the message.

BACKGROUND: Several studies have reported what seem to be false-positive results using the Food and Drug Administration (FDA)-approved HercepTest (Dako Corp, Carpinteria, CA) to profile Her-2/neu amplification and overproduction in breast carcinoma. False-positive status has been based on comparisons with gene copy enumeration by fluorescence in situ hybridization (FISH) and with comparisons to immunohistochemistry (IMH) results using a monoclonal antibody. However, simple overexpression by tumor cells that have normal gene copy has not been evaluated by profiling mRNA expression, ie, such cases could simply represent true-positive, transcriptionally upregulated overexpression. MATERIALS AND METHODS: Four hundred infiltrating ductal carcinomas of breast were evaluated by IMH using monoclonal (CB11; Ventana Medical Systems, Inc, Tucson, AZ) and polyclonal (HercepTest; Dako) antibodies after antigen retrieval (AR). A polyclonal antibody sans AR (PCA/SAR) was also used. All IMH stains were evaluated and scored according to the guidelines for the FDA-approved HercepTest. A total of 145 of 400 carcinomas were subsequently evaluated by direct and digoxigenin-labeled (Dig) FISH, and 144 of 400 were evaluated by detection of mRNA overexpression via autoradiographic RNA:RNA in situ hybridization. RESULTS: Overall HercepTest/CB11 IMH discordance was 12%. Expression of mRNA was highly concordant with FISH and DigFISH amplification and with CB11 and PCA/SAR immunohistology. IMH false-positive cases (no Her-2/neu gene amplification) occurred with both HercepTest (23%) and CB11 (17%), and the majority of false-positive results (34 of 44) were scored as 2+. All 2+ false-positive cases were mRNA-negative. Combined results of HercepTest and CB11 showed that 79% (38 of 48) of 3+ cases were Her-2/neu gene amplified, but only 17% (seven of 41) of 2+ cases had increased gene copy. CONCLUSION: Discordant HercepTest/FISH results, and to a lesser extent discordance with CB11 IMH, are most commonly false-positive results with a score of 2+. The 2+ score as defined in the guidelines for the FDA-approved HercepTest should not be used as a criterion for trastuzumab therapy unless confirmed by FISH. Determination of Her-2 gene copy number by FISH may be a more accurate and reliable method for selecting patients eligible for trastuzumab therapy.

Immunobiologic factors predictive of clinical outcome in diffuse large-cell lymphoma.

The prognostic importance of immunobiologic factors in diffuse large-cell lymphoma (DLCL) is studied in 105 consecutive DLCL patients. Multivariate results using the Cox proportional hazards model clearly indicate that the Ki-67 index (P = .002), a marker of cell proliferation activity, and the presence or absence of human leukocyte antigen-DR (HLA-DR) (P = .007) are strong predictors of survival even in the presence of established clinical factors of stage (P = .015) and symptoms (P = .050). Using these four variables, prognostic groups were formed identifying patient groups with varying degrees of risk. The group of patients with three or four risk factors present at the time of diagnosis had a median survival of 4 months compared with a median survival of 59 months for the group with no risk factors. Similarly, prognostic groups for disease-free survival (DFS) were constructed based on the proportional hazards model that involved B versus T phenotype (P = .035) and HLA-DR (P = .054). Median DFS for the patient group with one or two risk factors present was 11 months compared with 43 months with no risk factors present. This study suggests immunobiologic parameters are important predictors of clinical outcome in DLCL patients and are of value in identifying subgroups of patients who have not responded to currently available therapy. The practical significance of this study is to identify parameters that may suggest specific changes in therapy of patient subgroups.

Drug-resistance in multiple myeloma and non-Hodgkin's lymphoma: detection of P-glycoprotein and potential circumvention by addition of verapamil to chemotherapy.

The B-cell neoplasms, multiple myeloma and non-Hodgkin's lymphoma, frequently become drug resistant, despite initial responses to chemotherapeutic drugs. Tumor cells from eight patients with clinically drug-refractory disease were evaluated by immuno-histochemical staining for monoclonal immunoglobulin (Ig) expression, nuclear proliferation antigen, P-glycoprotein (P-gly) expression, and other cellular antigens. P-gly was detected on tumor cells from six of eight patients with drug-resistant disease. Of the six patients with P-gly-positive tumors, five patients had advanced multiple myeloma and one had a drug-refractory non-Hodgkin's lymphoma. Cellular RNA analysis confirmed the over-expression of P-gly. In an effort to overcome drug resistance, a pilot study evaluated possible verapamil enhancement of chemotherapy in these eight patients. All patients had developed progressive disease while receiving a regimen containing vincristine and doxorubicin, and seven of eight patients had previously received continuous infusion vincristine and doxorubicin plus oral dexamethasone (VAD). At the time of progressive disease, continuous infusion verapamil was added to the VAD regimen. Three of the eight patients who were refractory to vincristine and doxorubicin alone responded when verapamil was added to VAD. The three patients who responded had P-gly-positive tumors. Verapamil increased the intracellular accumulation of doxorubicin and vincristine in vitro for both a P-gly-positive myeloma cell line and tumor cells from two patients with end-stage myeloma which over-expressed P-gly. The dose-limiting side effect associated with the addition of verapamil to chemotherapy was temporary impairment of cardiac function, manifest as hypotension and cardiac arrhythmia. We conclude that P-gly expression occurs in drug-refractory B-cell neoplasms and may contribute to the development of clinical drug resistance. However, other factors, such as the proliferative activity of the tumor, may also play a role in determining response to chemotherapy. The administration of verapamil along with VAD chemotherapy may partially circumvent drug resistance in patients whose tumors over-express P-gly.

Diffuse small cleaved-cell lymphoma: a heterogeneous disease with distinct immunobiologic subsets.

PURPOSE AND METHODS: Diffuse small cleaved-cell lymphoma (DSCL) is a relatively uncommon non-hodgkin's lymphoma (NHL) in the United States and has not been the subject of recent in-depth study of factors predictive of outcome. It is unique among the NHL of intermediate grade because there is no evidence of a curable subset of patients. To investigate whether any laboratory data might predict outcome, we studied 33 cases collected during a 12-year period and correlated morphology, immunohistochemistry, and serum lactate dehydrogenase (LDH) with clinical data and outcome. RESULTS: We found that proliferative rate (Ki-67), cell lineage (T v B cell), and serum LDH were associated with significant differences in survival. A Ki-67 value greater than or equal to 20% was associated with a median survival of 20 months compared with 80 months for lower values (P = .0002); patients with tumors of T-cell lineage had a median survival of 20 months compared with 40 months for those with B-cell neoplasms (P = .0143); and a serum LDH greater than 225 IU/L was associated with a median survival of 8 months compared with 40 months for lower LDH levels (P = .0004). Blastoid morphology was also linked to a trend toward poor outcome (P = .08). Neither a history of low-grade lymphoma nor the presence of residual immunologically detectable follicles influenced outcome (P = .93 and .97, respectively). CONCLUSION: We conclude that high Ki-67, high LDH, and T-cell lineage each identify DSCL patients with poor outcome.

Infusional CHOP chemotherapy (CVAD) with or without chemosensitizers offers no advantage over standard CHOP therapy in the treatment of lymphoma: a Southwest Oncology Group Study.

PURPOSE: Two phase II studies were conducted to evaluate infusional cyclophosphamide, doxorubicin, vincristine, and dexamethasone chemotherapy, termed the CVAD regimen, alone (Southwest Oncology Group [SWOG] 9240) and with the chemosensitizers verapamil and quinine (SWOG 9125) to assess effects on response, survival, and toxicity in intermediate- and high-grade advanced-stage non-Hodgkin's lymphoma (NHL). The results were compared with the historic group of patients randomized to CHOP chemotherapy on Intergroup (INT) 0067 (SWOG 8516). PATIENTS AND METHODS: All patients had biopsy-proven intermediate- or high-grade NHL (lymphoblastic histology excluded), were ambulatory and previously untreated, and had bulky stage II, III, or IV disease. One hundred twelve patients were registered on SWOG 9240 and received cyclophosphamide 750 mg/m(2) by intravenous bolus day 1, doxorubicin 12.5 mg/m(2)/d and vincristine 0.5 mg/d delivered as a continuous 96-hour infusion on days 1 through 4, and dexamethasone 40 mg/d orally on days 1 through 4 (CVAD). Cycles were repeated every 21 days for eight cycles. One hundred patients on SWOG 9125 received the same chemotherapy and the chemosensitizers verapamil 240 mg bid and quinine 40 mg tid. Chemosensitizers were begun 24 hours before chemotherapy and continued for a total of 6 days. RESULTS: Eighty-one patients were eligible for each study. The complete response (CR) rates were 39% on SWOG 9125 and 31% on SWOG 9240. With a median follow-up of 5.8 years on SWOG 9125 and 4.5 years on SWOG 9240, the 2-year failure-free survival (FFS) rate was 42% on SWOG 9125 and 41% on SWOG 9240. Two-year overall survival (OS) rate was 64% on SWOG 9125 and 58% on SWOG 9240. These results are comparable to a 44% CR rate, a 2-year FFS of 46%, and 2-year OS of 63% observed in 225 patients treated with CHOP on INT 0067 (SWOG 8516). CONCLUSION: CVAD combination chemotherapy alone or with the chemosensitizers verapamil and quinine is not promising therapy with respect to improved response or OS in intermediate- and high-grade advanced-stage NHL.

Phase III randomized intergroup trial of subtotal lymphoid irradiation versus doxorubicin, vinblastine, and subtotal lymphoid irradiation for stage IA to IIA Hodgkin's disease.

PURPOSE: The management of early-stage Hodgkin's disease in the United States is controversial. To evaluate whether staging laparotomy could be safely avoided in early-stage Hodgkin's disease and whether chemotherapy should be a part of the treatment of nonlaparotomy staged patients, a phase III intergroup trial was performed. PATIENTS AND METHODS: Three hundred forty-eight patients with clinical stage IA to IIA supradiaphragmatic Hodgkin's disease were randomized without staging laparotomy to treatment with either subtotal lymphoid irradiation (STLI) or combined-modality therapy (CMT) consisting of three cycles of doxorubicin and vinblastine followed by STLI. RESULTS: The study was closed at the second, planned, interim analysis because of a markedly superior failure-free survival (FFS) rate for patients on the CMT arm (94%) compared with the STLI arm (81%). With a median follow-up of 3.3 years, 10 patients have experienced relapse or died on the chemoradiotherapy arm, compared with 34 on the radiotherapy arm (P <.001). Few deaths have occurred on either arm (three deaths on CMT and seven deaths on STLI). Treatment was well tolerated, with only one death on each arm attributed to treatment. CONCLUSION: These results demonstrate that it is possible to obtain a high FFS rate in a large group of stage IA to IIA patients without performing staging laparotomy and that three cycles of chemotherapy plus STLI provide a superior FFS compared with STLI alone. Extended follow-up is necessary to assess freedom from second relapse, overall survival, late toxicities, patterns of treatment failure, and quality of life.

Methods to detect P-glycoprotein and implications for other drug resistance-associated proteins.

The problem of tumor cell drug resistance remains a barrier to the successful treatment of many neoplastic diseases. Problems of tumor cell heterogeneity and expression of multiple mechanisms of drug resistance complicate treatment strategies. Indeed, even that form of resistance to natural product anticancer agents, multidrug resistance (MDR), can have multiple mechanisms. Compounding these problems is the use of different methodologies and different reagents to assess expression of the most widely studied form of MDR, that due to increased expression of the MDR1 gene and its product, P-glycoprotein (Pgp). In this paper, we discuss problems associated with assay variability and accurate measurement of markers of drug resistance, and summarize consensus findings of the St Jude Workshop on methods to detect Pgp in tumors.