Management of proximal metaphyseal curvilinear tibial fractures in 25 skeletally immature dogs (2009 to 2020)

OBJECTIVES

To describe the occurrence, management and outcome of proximal metaphyseal curvilinear tibial fractures in skeletally immature dogs.

MATERIALS AND METHODS

A multi-centre retrospective review was conducted, searching for skeletally immature dogs presenting with proximal metaphyseal curvilinear tibial fractures between January 2009 and September 2020. Signalment, fracture description and case management data were retrieved. Outcome was assessed by retrospectively evaluating follow-up radiographs, hospital records and an owner questionnaire.

RESULTS

Twenty-five dogs met the inclusion criteria. All but one fracture was a result of minimal trauma. Twenty fractures were managed with internal fixation, two with external fixation and three conservatively. All 25 fractures healed. Eight major complications occurred in seven of 25 (28%) dogs. Twelve minor complications occurred in 10 of 25 (40%) dogs. Owner questionnaire data were available for 12 of 25 dogs; 11 of 12 were reported as having full function and one of 12 as having acceptable function at the time of questioning (median 34.5 months following presentation). At final follow-up, either by clinical examination or owner questionnaire, full function was achieved in 22 of 25 patients and acceptable function in three of 25.

CLINICAL SIGNIFICANCE

This study reported a series of proximal metaphyseal tibial fractures in skeletally immature dogs. The most common fixation method was internal fixation, which frequently resulted in full limb function at final follow-up. Owners reported outcome as fully functional in all dogs that underwent surgery at first presentation and had owner follow-up available, though positive outcomes may have been affected by participation bias.

Retrospective study of complications associated with surgically-placed gastrostomy tubes in 43 dogs with septic peritonitis

OBJECTIVES

To determine the safety of surgically-placed gastrostomy feeding tubes in dogs with septic peritonitis.

MATERIALS AND METHODS

Retrospective analysis of 43 dogs with septic peritonitis that had undergone surgical exploration and gastrostomy tube (de Pezzer or Foley) placement as part of the surgical procedure. Postoperative recovery times, hospitalisation times, complication rates and overall survival times were documented.

RESULTS

The most common cause of septic peritonitis was dehiscence of an enterotomy or enterectomy site. Fifteen dogs had a Foley gastrostomy tube placed and 28 had a de Pezzer gastrostomy tube placed. The median time from surgery to the start of enteral nutrition was 16 hours (range 3 to 28 hours). There were no major complications relating to the gastrostomy tube; minor complications occurred in 11 (26%) patients. The overall median time spent in hospital was 5 days (range 3 to 29 days) for patients surviving to discharge and 22 (51%) dogs survived overall.

CLINICAL SIGNIFICANCE

Gastrostomy feeding tubes provide a safe way to provide enteral nutrition to dogs with septic peritonitis; they are associated with a low complication rate in these patients.

Comparison of the use of LigaSure versus a standard technique for tonsillectomy in dogs

The principal aim of this study was to document the effectiveness of tonsillectomy in dogs using a vessel-sealing device compared with a standard technique with tonsillectomy forceps. A secondary aim of the study was to document histopathological changes of the excised tonsillar tissue in dogs with brachycephalic obstructive airway syndrome. 20 dogs were studied. The time taken to remove a tonsil using LigaSure was a mean of 44.8 seconds (sd 15 seconds, 95 per cent CI 40  to 57 seconds) and with the standard technique a mean of 305.9 seconds (sd 67 seconds, 95 per cent CI 272  to 349 seconds). Significantly less haemorrhage occurred using LigaSure compared with the standard technique. Histopathology of the tonsils was characterised by multifocal neutrophilic and lymphocytic inflammation, and 1-2 mm of heat-induced coagulation necrosis at the cut edge of LigaSure tonsils. This study shows that LigaSure is significantly faster and resulted in less bleeding than the standard technique.

Liposomal encapsulated doxorubicin (Caelyx) in the treatment of relapsed aggressive non-Hodgkin's lymphoma: A phase II study

Aggressive non-Hodgkin's lymphoma (NHL), such as diffuse large B-cell lymphoma, can be cured in approximately 50% of cases, but those cases that recur and are not amenable to high-dose chemotherapy rely on palliative chemotherapy to improve symptoms and prolong life. Anthracyclines are associated with a high response rate in aggressive NHL but extended treatment results in cardiotoxicity. Liposomal encapsulated doxorubicin has been shown in other tumor types to allow for extended treatment with doxorubicin, but is associated with a low cardiac risk. The present study aimed to assess the response rate, survival and cardiac risk of patients with relapsed aggressive NHL treated with liposomal encapsulated doxorubicin. Eighteen patients with relapsed aggressive NHL were treated with liposomal encapsulated doxorubicin (40 - 50 mg/m2) for a planned six cycles. Some 83% of patients had diffuse large B-cell or mantle cell NHL. Four patients had a partial response (23%), whereas five patients had stable disease. None had a complete response. Eight patients progressed when receiving the liposomal encapsulated doxorubicin therapy. The median survival time was 34 weeks, and the median progression-free survival was 15.7 weeks. Overall survival was 50% at 6 months and 39% at 12 months. Progression-free survival was 33% at 6 months and was 28% at 12 months. The mean ejection fraction pre- and post-liposomal encapsulated doxorubicin treatment remained the same. Only one patient had a drop in ejection fraction to <50%. Liposomal encapsulated doxorubicin offers another choice to patients seeking palliation from their lymphoma recurrence with a response rate of 23% that was well tolerated and had a minimal cardiotoxic risk.

Activity of lenalidomide in a phase II trial for T-cell lymphoma: Report on the first 24 cases

8524

Background: Novel therapies are needed to improve outcomes in T-cell lymphomas. We report the interim results of a prospective multicenter trial evaluating lenalidomide in T-cell lymphomas. Methods: Patients with relapsed and refractory T-cell lymphomas other than mycosis fungoides were prescribed oral lenalidomide (25mg daily) on days 1 to 21 of each 28 day cycle, with standardized dose reductions for toxicity. Treatment continued until disease progression, death or unacceptable toxicity. The primary endpoint was overall response rate, and secondary endpoints were complete and partial response rates, progression-free and overall survival (PFS, OS), and safety. The two-stage design allows for up to 40 patients. Results: At the time of this interim analysis, 24 patients were enrolled in this study and 23 were evaluable for response. The median age was 65 years. ECOG PS was 0–1 (n=15), 2 (n=7), 3 (n=2). The histology was peripheral T-cell unspecified (PTCL-u, n=10), angioimmunoblastic (n=7), anaplastic large cell (n=5), enteropathic T-cell (n=1) and hepatosplenic gamma/delta (n=1). Median number of prior therapies was 1 (range, 0–4), and three had prior autologous stem cell transplant. Four patients were previously untreated and not candidates for combination chemotherapy. Median time from completion of prior therapy to the start of lenalidomide was 8 months (range, 1–48 months). The overall response rate was 7/23 (30%); all were partial responses. Two patients had stable disease (SD) for ≥3 cycles. Responses were seen in anaplastic, angioimmunoblastic, and PTCL-u histologies. Median PFS was 96 days (range, 8–696 days). Median OS was 241 days (range, 8–696+ days). Among the 9 patients with SD or better, median PFS was 168 days and median OS has not yet been reached with 241–696 days of follow-up. The most common grade 4 adverse event was thrombocytopenia (33.3%). The most common grade 3 adverse events were neutropenia (20.8%), febrile neutropenia (16.7%), and pain NOS (16.7%). Conclusions: In relapsed and refractory T-cell lymphomas, oral lenalidomide monotherapy has clinical activity and toxicity is consistent with the known profile of lenalidomide. Further study of lenalidomide in these diseases is warranted.

[Table: see text]

Comparison of lenalidomide plus dexamethasone therapy used at first relapse versus later salvage therapy in relapsed or refractory multiple myeloma patients

8594

Background: The benefit of initiating lenalidomide plus dexamethasone at first relapsed was evaluated in this subset analysis from phase III studies in patients with relapsed or refractory multiple myeloma (MM). Methods: Patients from the randomized, multicenter clinical trials MM-009 and MM-010 who had received at least 1 prior treatment and were not resistant to dexamethasone were treated with lenalidomide (25 mg daily for 21 days of every 28 day cycle) plus dexamethasone (40 mg on days 1–4, 9–12, and 17–20 every 28 days for 4 months, then 40 mg on days 1–4 every cycle thereafter until disease progression or intolerance), or dexamethasone (same dose and schedule) plus placebo. Baseline characteristics such as age, sex, ECOG score, and baseline β2-microglobulin levels between the 2 patient groups were similar, however, median time from diagnosis and prior therapy were statistically different. Results: Multivariate analysis showed that more prior therapies is associated with shorter time-to-progression (TTP). Patients who received 1 prior therapy demonstrated a significant improvement in outcomes such as TTP, progression-free survival (PFS), overall response rate (ORR), complete response/very good partial response rate (CR/VGPR), median duration of treatment and overall survival (OS) after first relapse compared with those who received ≥ 2 prior therapies ( Table ). Toxicity, rate of dose reduction, or treatment discontinuation in the cohort with 1 prior therapy did not increase, despite longer treatment. Conclusions: When used at first relapse compared with salvage therapy, lenalidomide plus dexamethasone treatment resulted in significantly prolonged TTP, PFS, and OS, and an improved quality of response. Lenalidomide plus dexamethasone should be considered at an early stage of therapy for patients with MM.

[Table: see text]

[Table: see text]

Detection of genes with moderate effects on disease resistance using ovine mhc and resistance to nematodes as an example

Detecting some of the genes that influence disease resistance would improve our understanding of the processes that cause disease and also simplify disease control. Genes within the major histocompatibility complex (mhc) are strong candidates for disease resistance and they have been intensely studied for the last 30 years. Recently, several groups working independently have reported the existence of alleles within the mhc that are associated with enhanced resistance to nematode infection. This article uses hindsight to describe some of the potential pitfalls that hinder the search for valid disease resistance genes. The search requires a good understanding of disease biology, molecular genetics, statistical genetics and especially, the design and analysis of experiments. The power to detect mhc effects is quite low and is quite sensitive to the frequency of the putative resistance alleles.

ZIO-101 (S-dimethylarsino-glutathione): Phase I/II trials in advanced/progressive multiple myeloma

8109

Background: ZIO-101(S-dimethylarsino-glutathione), a novel organic arsenic, is active against multiple cancers including myeloma in vitro and in animal models. In vitro, it is active at low concentrations in cancers resistant to arsenic trioxide. Anti-cancer activity is multifaceted and is mediated by disrupted mitochondrial function, increased reactive oxygen species (ROS) production, modified signal transduction and anti-angiogenesis. Methods: (1) Phase I/II study to determine maximum tolerated dose (MTD), dose- limiting toxicity (DLT), safety-profile and preliminary efficacy in patients with advanced/progressive myeloma receiving ZIO-101 daily for 5 consecutive d every 4 w; (2) comparison of this schedule at MTD with a schedule of 420 mg/me2/d twice/w for 3 w every 4 w. Results: (1) phase I/ II: 19 patients have been treated so far. Median age is 61 y (range, 41–84 y). Median N prior therapies was 8 (range, 4–10). ZIO-101 was well-tolerated; MTD was 420 mg/me2/d for the 5 d schedule, and DLT was transient confusion /ataxia. No clinically- important biochemical, bone marrow, or cardiac toxicities were seen and there was neither neuropathy nor QTc-prolongation. Pain during peripheral infusion was reported in some patients. Anemia was the only adverse event = grade-3 in 25% of subjects. 6 of 14 evaluable subjects had stable disease (SD) =8 w and 2, SD > 6 mo. Accrual to the phase II portion continues. Conclusions: ZIO-101 was well- tolerated. In the daily for 5 consecutive d every 4 w schedule, the MTD is 420 mg/me2/d and DLT, transient confusion /ataxia. There was SD in 43% of patients with advanced/progressive myeloma, of whom half are beyond 6 months. Accrual into the phase II part of this study continues.

No significant financial relationships to disclose.

A phase II study of bortezomib in mantle cell lymphoma: the National Cancer Institute of Canada Clinical Trials Group trial IND.150

BACKGROUND

We evaluated the activity and toxic effects of bortezomib in patients with mantle cell lymphoma.

PATIENTS AND METHODS

Thirty patients, including 29 eligible patients, were enrolled; 13 had received no prior chemotherapy. The dose of bortezomib was 1.3 mg/m2 given on days 1, 4, 8 and 11 every 21 days. Response was assessed according to the International Workshop Criteria for non-Hodgkin's lymphoma and toxicity graded using the National Cancer Institute Common Toxicity Criteria version 2.0.

RESULTS

There were 13 responding patients (46.4%; 95% confidence interval=27.5% to 66.1%), including one unconfirmed complete remission. The median response duration was 10 months. Response rates were similar in previously untreated (46.2%) and treated (46.7%) patients. Neurological toxicity and myalgia led to treatment discontinuation in 10 patients after two to seven treatment cycles. Five serious adverse events (including two deaths) associated with fluid retention were observed in the first 12 patients. We subsequently excluded patients with baseline effusions, dyspnea or edema; no further events were seen.

CONCLUSIONS

Bortezomib is active in treating patients with mantle cell lymphoma. While cumulative neuromuscular toxic effects limited therapy duration and specific issues related to fluid retention require further evaluation, continued study of this drug in combination regimens is warranted.

International uniform response criteria for multiple myeloma

New uniform response criteria are required to adequately assess clinical outcomes in myeloma. The European Group for Blood and Bone Marrow Transplant/International Bone Marrow Transplant Registry criteria have been expanded, clarified and updated to provide a new comprehensive evaluation system. Categories for stringent complete response and very good partial response are added. The serum free light-chain assay is included to allow evaluation of patients with oligo-secretory disease. Inconsistencies in prior criteria are clarified making confirmation of response and disease progression easier to perform. Emphasis is placed upon time to event and duration of response as critical end points. The requirements necessary to use overall survival duration as the ultimate end point are discussed. It is anticipated that the International Response Criteria for multiple myeloma will be widely used in future clinical trials of myeloma.

Lenalidomide plus high-dose dexamethasone provides improved overall survival compared to high-dose dexamethasone alone for relapsed or refractory multiple myeloma (MM): Results of a North American phase III study (MM-009)

7521

Background: Lenalidomide is a novel, orally administered, immunomodulatory drug (IMiD) that has single-agent activity against MM and additive effects when combined with dexamethasone (Dex). Methods: In this phase 3, multicenter, double-blind trial, 354 patients (pts)with relapsed or refractory MM were treated with Dex 40 mg daily on days 1–4, 9–12, 17–20 every 28 days and were randomized to receive either lenalidomide (Len) 25 mg daily orally on days 1–21 every 28 days or placebo. Beginning with cycle 5, Dex was reduced to 40 mg daily on days 1–4 only, every 28 days. Patients were stratified with respect to B2M (≤ 2.5 vs. > 2.5 mg/mL), prior stem cell transplant (none vs. ≥ 1), and number of prior regimens (1 vs > 1). The treatment arms were well balanced for prognostic features. Results: The overall response rate was greater with Len-Dex than with Dex-placebo (59.4% vs. 21.1%; p < 0.001). Complete responses were achieved in 12.9% of pts treated with Len-Dex and 0.6% of pts treated with Dex-placebo. The median time to progression (TTP) for pts treated with Len-Dex was 11.1 months compared to 4.7 months for pts treated with Dex-placebo (p < 0.000001). Median overall survival was higher with Len-Dex (not reached) compared to Dex-placebo (24 months) (hazard ratio 1.76, p = .0125). Grade 3–4 neutropenia was more frequent with combination therapy than with Dex-placebo (24% vs. 3.5%), however ≥ grade 3 infections were similar in both groups. Thromboembolic events occurred in 15% of pts treated with Len-Dex and in 3.5% of pts treated with Dex-placebo. Atrial fibrillation occurred in 8 pts and CHF developed in 4 pts treated with Len-Dex. Conclusions: Considering the ease of oral administration, higher response rate, longer time to progression and overall survival benefit, the combination of lenalidomide-dexamethasone may very well represent the treatment of choice for early refractory or relapsing multiple myeloma. The relatively infrequent side effects should not detract from these improvements, but the use of prophylactic antithrombotic therapy should be considered for patients treated with the combination of lenalidomide and dexamethasone.

[Table: see text]

Gemcitabine, dexamethasone and cisplatin is an active and non-toxic chemotherapy regimen in relapsed or refractory Hodgkin's disease: a phase II study by the National Cancer Institute of Canada Clinical Trials Group

BACKGROUND

Gemcitabine (difluorodeoxycytidine) is active as a single agent in Hodgkin's disease and has been used successfully in combination with cisplatin to treat a variety of solid tumors.

PATIENTS AND METHODS

We evaluated the combination of gemcitabine/dexamethasone/cisplatin (GDP) as salvage chemotherapy in 23 patients with relapsed or refractory Hodgkin's disease (median age 36 years, range 19-57). Treatment consisted of gemcitabine 1000 mg/m(2) intravenously on days 1 and 8, dexamethasone 40 mg orally days 1-4 and cisplatin 75 mg/m(2) on day 1, every 21 days as an outpatient. Response was assessed following two cycles of treatment.

RESULTS

There were four complete responses and 12 partial responses for a response rate of 69.5% (95% confidence interval 52% to 87%); the remaining seven patients had stable disease and no patient progressed on treatment. All patients had successful stem cell mobilization and underwent transplantation with a median 10.6 x 10(6) CD34+ cells/kg. Hematological toxicity from GDP was mild (grade 3 neutropenia 8.6%, grade 3 thrombocytopenia 13%).

CONCLUSIONS

In summary, GDP is an active regimen for patients with relapsed or refractory Hodgkin's disease. The response rate is similar to the rates of other current salvage regimens, it can be given to outpatients with tolerable toxicity and it does not inhibit the mobilization of autologous stem cells.

Optimising parameters for peripheral blood leukapheresis after r-metHuG-CSF (filgrastim) and r-metHuSCF (ancestim) in patients with multiple myeloma: a temporal analysis of CD34(+) absolute counts and subsets

Patients (n = 69) with multiple myeloma undergoing peripheral blood stem cell collection (PBSC) were treated with cyclophosphamide and a combination of recombinant methionyl human granulocyte colony-stimulating factor (r-metHuG-CSF, filgrastim) and recombinant methionyl human stem cell factor (r-metHuSCF, ancestim). The objectives of this study were to determine: (1) The proportion of patients reaching a target yield of >or=5 x 10(6) CD34(+) cells/kg in one or two successive large-volume (20 liter) leukapheresis procedures; (2) the optimal collection time for leukapheresis; (3) mobilization kinetics of CD34(+) subsets in response to G-CSF/SCF. All patients were mobilized with cyclophosphamide (2.5 g/m(2)) on day 0 followed by filgrastim (10 microg/kg ) plus ancestim (20 microg/kg) commencing day 1 and continuing to day 11 or 12. Of the 65 evaluable patients, 57 were considered not heavily pretreated and 96.5% obtained a target of >or=5 x 10(6)/kg in one collection. The median CD34(+) cells/kg was 39.5 x 10(6) (range: 5.2-221.2 x 10(6)). Subset analysis demonstrated the number of CD38(-), CD33(-), and CD133(+) peaked at day 11; and CD34(+), CD90(+) cells peaked at day 10. The optimum day for leukapheresis was determined to be day 11. The median absolute peripheral blood CD34(+) cell numbers on day 11 was 665 x 10(6)/l (range: 76-1481 x 10(6)/l). Eight of the 10 heavily pretreated patients were evaluable: three achieved the target dose in one leukapheresis (37.5%) and three (37.5%) achieved the target dose with two leukaphereses. Use of this mobilization strategy allowed the collection of high numbers of CD34(+) cells and early progenitors and the ability to predictably schedule leukapheresis.

Zoledronic acid versus pamidronate in the treatment of skeletal metastases in patients with breast cancer or osteolytic lesions of multiple myeloma: a phase III, double-blind, comparative trial

PURPOSE

Zoledronic acid, a new and more potent bisphosphonate, was compared with pamidronate, the current standard treatment for patients with osteolytic or mixed bone metastases/lesions.

PATIENTS AND METHODS

A total of 1,648 patients with either Durie-Salmon stage III multiple myeloma or advanced breast cancer and at least one bone lesion were randomly assigned to treatment with either 4 or 8 mg of zoledronic acid via 15-minute intravenous infusion or 90 mg of pamidronate via 2-hour intravenous infusion every 3 to 4 weeks for 12 months. The primary efficacy endpoint was the proportion of patients experiencing at least one skeletal-related event over 13 months.

RESULTS

The proportion of patients with at least one skeletal-related event was similar in all treatment groups. Median time to the first skeletal-related eventwas approximately 1 year in each treatment group. The skeletal morbidity rate was slightly lower in patients treated with zoledronic acid than in those treated with pamidronate, and zoledronic acid (4 mg) significantly decreased the incidence and event rate for radiation therapy to bone, both overall and in breast cancer patients receiving hormonal therapy. Pain scores decreased in all treatment groups in the presence of stable or decreased analgesic use. Zoledronic acid (4 mg) and pamidronate were equally well tolerated; the most common adverse events were bone pain, nausea, fatigue, and fever and < 5% of serious adverse events were related to the study drug. The incidence of renal impairment among patients treated with 4 mg of zoledronic acid via 15-minute infusion was similar to that among patients treated with pamidronate.

CONCLUSIONS

Zoledronic acid (4 mg) via 15-minute intravenous infusion was as effective and well tolerated as 90 mg of pamidronate in the treatment of osteolytic and mixed bone metastases/lesions in patients with advanced breast cancer or multiple myeloma. (Can-

Intervention with the hypoxic tumor cell sensitizer etanidazole in the combined modality treatment of limited stage small-cell lung cancer. A one-institution study

PURPOSE

We report the toxicity, patterns of failure and survival of a cohort of patients with limited disease (LD) small-cell lung cancer (SCLC) treated with combined radiation and chemotherapy. During the course of thoracic irradiation, we added intravenous (i.v.) etanidazole (SR-2508, a third-generation 2-nitroimidazole) as a hypoxic cell sensitizer in an attempt to reduce the primary local failure rate and improve survival.

METHODS AND MATERIALS

Between July 1988 and August 1990, 30 consecutive patients with limited disease SCLC were enrolled and treated on a Phase II protocol receiving a standard combination chemotherapy regimen utilizing i.v. cisplatin 25 mg/m2/day x 3 days, i.v. etoposide 100 mg/m2/day x 3 days alternating with intravenous cyclophosphamide 1000 mg/m2/day, intravenous doxorubicin 15 mg/m2, and intravenous vincristine 2 mg (CAV) to a total of six cycles every 3 weeks. Radiotherapy and etanidazole were started after the first cycle of chemotherapy. Etanidazole was administered intravenously at a dose of 2 g/m2 three times per week for a total of 30 g/m2 during the course of thoracic radiation that delivered 50.00 Gy tumor dose in 25 fractions in an overall time of 6 weeks.

RESULTS

The overall response rate of the primary lesion in the thorax was 96% (CR + PR), with 64% complete responses. The median time to treatment failure was 18 months. Of the patients that have relapsed, only 18% failed in the thorax (alone or concomitant with other sites). This is a marked improvement compared to the 40-50% rate reported in the literature. The 2-year crude survival was 46%. The 3- and 5-year crude survival rate with no evidence of disease was 33 and 30%, respectively. We have observed a 10% increase in the incidence of transient etanidazole related peripheral neuropathies compared to previous etanidazole studies not utilizing systemic chemotherapy. There was no increased incidence of radiation esophagitis, pulmonary toxicity, or nephro- or myelotoxicity over and above what has been routinely observed with this radio/chemotherapy regimen. There were no treatment related deaths.

CONCLUSION

The moderate increase in etanidazole-related transient peripheral neuropathies could have been related to the concomitant use of etanidazole with vincristine and cisplatin. Although the almost 50% improvement in the incidence of tumor failure rate in the thorax in this small group of patients did not correlate with an equal marked improvement in their survival, the 5-year survival outcome in our series is at least equal or better than the best reports in the literature of larger clinical trials. We believe there is sufficient data from this study, particularly the improvement of local tumor control, to warrant a large randomized controlled clinical trial, using the most current systemic chemotherapy with concomitant thoracic irradiation with or without the most effective available hypoxic cell cytotoxic/sensitizer.

Randomized trial of interferon maintenance in multiple myeloma: a study of the National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To determine whether interferon maintenance therapy improves overall survival and response duration in patients with multiple myeloma who have responded to induction therapy with melphalan and prednisone.

PATIENTS AND METHODS

In a multicenter trial, patients with symptomatic clinical stage I and stage II and III multiple myeloma were registered at diagnosis and those who responded to melphalan-prednisone (MP) were randomized either to receive interferon (2 mU/m2) subcutaneously three times per week or no maintenance. MP was discontinued in both groups once a stable response plateau of the monoclonal protein was reached. Interferon was continued until relapse, and then was restarted on subsequent response to MP. Interferon toxicity was recorded using a self-report diary. Survival and response duration were calculated using life-table methods, and were adjusted in the analysis for imbalances in baseline prognostic factors.

RESULTS

Four hundred two patients were registered and 176 responders were randomized (85 to interferon and 91 to control). At a median follow-up time of 43 months, the median survival duration was 43 months for interferon and 35 months for control (P = .16), but when adjusted for chance imbalances in baseline prognostic factors (mainly performance status), the median survival duration was 44 months and 33 months for interferon and control, respectively (P = .049). Progression-free survival from randomization to first relapse also favored interferon (unadjusted P < .002; adjusted P < .003). Interferon toxicity caused 58% of patients to reduce their dose, of which 84% were able to return to the initial dose; 14% had to discontinue interferon treatment.

CONCLUSION

Interferon maintenance therapy improves progression-free and overall survival of patients with multiple myeloma who respond to melphalan and prednisone. Toxicity is substantial and must be weighed by patients against the potential benefits in response duration and survival.

Modified adriamycin-vincristine-dexamethasone (m-VAD) in primary refractory and relapsed plasma cell myeloma: an NCI (Canada) pilot study. The National Cancer Institute of Canada Clinical Trials Group

The purpose of this single arm phase II study was to test a modified version of the three drug combination vincristine, adriamycin and dexamethasone (m-VAD), in which intravenous vincristine (0.4 mg/d) and adriamycin (9 mg/m2 per day) infusions are administered for only 2 h on days 1-4 of each 28 d cycle, in patients with refractory multiple myeloma. In addition, only two 4 d courses of dexamethasone 40 mg/d was given during each cycle. The entry criteria for 44 patients included plasma cell myeloma and a measurable monoclonal peak, either refractory to initial treatment with melphalan and prednisone, or resistant to melphalan and prednisone after initially responding (resistant relapsed disease, 27 patients). Patients treated previously with chemotherapy other than melphalan and prednisone were excluded. There were no complete responses. Of the 41 evaluable patients who completed at least one course of therapy 11 had a partial response (27%, 95% C.I. 14-40%). The response rates were 19% for primary refractory disease patients, and 32% for those with resistant relapsed disease. The median duration of response was 4 months. The median survival for all 44 patients was 7.6 months (5.5 months for primary refractory patients, and 10 months for relapsed resistant disease patients). Episodes of documented bacterial infection occurred in 12 patients, and 10 patients had minor viral infection. The dexamethasone dose was reduced in 12 patients. The median neutrophil nadir was 1.2 x 10(9)/l, and median platelet nadir was 147 x 10(9)/l. Five deaths were judged as treatment related and occurred during marrow cytopenia. The results of this modified form of VAD are inferior to that reported previously for 4 d continuous infusions of vincristine and doxorubicin. This could be related to either patient selection factors, or to a reduction of the efficacy of the drug combination produced by either the shortened intravenous infusions and/or omission of one 4 d course of dexamethasone.

Does gallium uptake in the pulmonary hila predict involvement by non-Hodgkin's lymphoma?

67Ga imaging of non-Hodgkin's lymphoma is useful for evaluating the presence of viable tumour in a residual mass after treatment. However, we have frequently seen gallium uptake in the pulmonary hila without other evidence of lymphoma. To study the significance of this finding, 79 patients with intermediate grade non-Hodgkin's lymphoma were reviewed. Thirty-seven (47%) had abnormal hilar gallium uptake. Twenty-three of these could be fully evaluated, and only five (22%) had hilar lymphoma. A pattern of bilateral, symmetric hilar uptake was seen in 19 patients, but only one had evidence of lymphoma. In 15 cases, this pattern was seen only on single photon emission computed tomography (SPECT). The aetiology of this uptake remains unknown. It is not treatment related, as 12 patients had hilar gallium uptake prior to chemotherapy. Unless confirmed by other methods, hilar gallium uptake should not be attributed to lymphoma, and should not influence patient management.

Elevated c-myc messenger RNA in multiple myeloma cell lines

Oncogene analyses of four human myeloma cell lines provided no indication of gene amplification or rearrangement using DNA probes for the met, raf, abl, mos, erb B, Her-2-neu, fos, myb-7, fms, L-myc, sis, and myb-1 genes. However, a consistent elevation of up to 23-fold in the level of c-myc mRNA was observed in all of the cell lines studied. No restriction fragment length polymorphism (in exons one, two, or three) or c-myc gene amplification has as yet been demonstrated to account for the c-myc mRNA elevation. The c-myc mRNA has a half-life of 25 min which is comparable to that observed in other systems. The elevation in c-myc mRNA is further evidence for the role of the c-myc proto-oncogene in the pathogenesis of myeloma.

Reassessment of the relationship between M-protein decrement and survival in multiple myeloma

The relationship between percentage M-protein decrement and survival is assessed in 134 multiple myeloma patients. The correlation did not achieve statistical significance (P = 0.069). Multivariate analysis using the Cox proportional hazards model, including a number of previously recognised prognostic factors, showed only percentage M-protein decrement, creatinine and haemoglobin to be significantly correlated with survival. However, the R'-statistic for each of these variables was low, indicating that their prognostic power is weak. We conclude that neither the percentage M-protein decrement nor the response derived from it can be used as an accurate means of assessing the efficacy of treatment in myeloma. Mature survival data alone should be used for this purpose.

Dose intensity analysis of melphalan and prednisone in multiple myeloma

The average relative dose intensity (DI) of conventional oral melphalan and prednisone therapy received by 93 newly diagnosed multiple myeloma patients was correlated with survival and with percent reduction in M-protein. A survival advantage was shown with increasing average relative DI of melphalan and prednisone. Multivariate analysis showed survival to correlate with increasing DI of prednisone (P = .05) but not with the DI of melphalan (P = .93) nor with the percent decrement in M-protein (P = .10). These results suggest that the initial management of myeloma should be reassessed, with particular emphasis on more intensive therapy employing high-dose steroids.

A randomized trial of maintenance versus no maintenance melphalan and prednisone in responding multiple myeloma patients

In order to assess the role of maintenance melphalan and prednisone (MP) in responding multiple myeloma patients, 185 eligible patients who responded to initial MP with stabilization for at least 4 months were randomized to either stop treatment and resume therapy at relapse or to continue MP until relapse. Time to first relapse was significantly shorter in the no maintenance group (P = 0.0011), however 57% of the no maintenance patients had a second response when MP was restarted and others had minor improvement. The time to final progression on MP, which reflects the duration of disease control by MP, was therefore longer for the no maintenance group (median = 39 months) compared to the maintenance group (median = 31 months) although the observed difference was not statistically significant (P = 0.086). Median survival from start of MP in the maintenance group (46 months) was also not significantly different than the no maintenance group (51 months) (P = 0.587). Multifactor analysis of the randomized patients demonstrated shorter total remission duration and shorter survival in patients who had an initially rapid response to therapy or a lesser reduction in serum M-protein concentration.

Weekly cyclophosphamide and alternate-day prednisone: an effective secondary therapy in multiple myeloma

Intravenous or oral cyclophosphamide, 150-250 mg/m2 (500 mg maximum), once per week with alternate-day oral prednisone, 100 mg, was given to 57 myeloma patients resistant to melphalan and prednisone (MP). Seven responses in 28 primary MP-resistant patients and ten responses in 29 secondary MP-resistant patients were observed. Previous response to MP was not a significant factor in predicting response to weekly cyclophosphamide and alternate-day prednisone. The results suggest that the regimen of weekly cyclophosphamide and alternate-day prednisone may be as effective as more aggressive regimens in the treatment of patients with myeloma who have failed MP therapy. However, a randomized trial would be required to determine the relative contributions of cyclophosphamide and prednisone to the effectiveness of this regimen.

Are the current criteria for response useful in the management of multiple myeloma?

One hundred seventy-three patients with multiple myeloma were treated from the time of diagnosis with standard oral melphalan and prednisone at 28-day intervals until they became refractory to treatment. Response to treatment was determined according to the Chronic Leukemia-Myeloma Task Force (TF) criteria, and independently according to the Southwest Oncology Group (SWOG) criteria. Survival by disease stage and response according to the two sets of criteria were analyzed for patients living longer than 3 months. The median survival of responding and nonresponding (TF criteria) stage II patients was 43.8 and 40.3 months, respectively (P = .29). By SWOG criteria, median survival for responding and nonresponding stage II patients was 48.3 and 39.0 months, respectively (P = .12). In stage III patients, median survival for responders and nonresponders (TF criteria) was 34.0 and 21.7 months, respectively (P = .01), compared with 35.5 and 24.4 months (P = .04) by SWOG criteria. These data would suggest that the TF criteria predicts a survival disadvantage only in very advanced myeloma and that applying the stricter limits for the definition of response of the SWOG does not further aid in selecting a subgroup of myeloma patients with poorer survival.

Cytogenetic and biological characterization of two new human plasma cell lines

Two new human plasma cell lines designated as ACB-885 and ACB-1085 have been established from a 39-year-old patient with multiple myeloma. These cell lines have definitive plasma cell features by morphologic examination, and essentially all of the cells are positive for cytoplasmic IgG kappa immunoglobulin. These cells are negative for standard T-cell surface markers and mature B-cell markers, such as B1, B2, and HLA-DR, but are strongly positive for the antigen defined by OKT-10. The cells are negative for Epstein-Barr virus. The cell lines have a doubling time of 30-35 hours and a growth fraction approaching 100%. Cytogenetic analysis showed a 2n chromosome number of 45-46 with very similar karyotypic abnormalities in both the plasma cell lines and the original tumor material. One of the chromosomes in each of the pairs of chromosomes number #1, #2, #6, #7, #8, #10, #12, #13, and #22 were consistently missing. These were replaced by eight marker chromosomes that resulted from chromosomal rearrangements involving mainly these missing chromosomes. Almost all of the breakpoints occurring in the marker chromosomes were identified, and eight of these breakpoints have been reported in other studies of myeloma plasma cells. Homogeneously staining regions were observed in two marker chromosomes suggesting gene amplification in these chromosomal regions.

Loss of viability and induction of DNA damage in human leukemic myeloblasts and lymphocytes by m-AMSA

The effects of m-AMSA on in vitro viability and on the induction of DNA damage were examined in low-growth-fraction cell populations of human leukemic myeloblasts and normal lymphocytes. A significant individual variation in the drug-induced reduction of in vitro viability was observed in studies with five selected leukemic patients. The concentration of m-AMSA required to reduce viability by 50% within 48 h ranged from 0.25 microM to in excess of 5.0 microM for the leukemic myeloblasts as against about 2.0 microM for the samples of normal lymphocytes. Alkaline elution studies showed that m-AMSA induced protein-associated DNA strand breaks (PADB) in both myeloblasts and lymphocytes. Depending upon the m-AMSA concentration, there was a 4- to 9-fold difference in the level of PADBs induced by a given drug concentration in the myeloblasts of eight patients studied. The level of PADBs was saturable with respect to both drug concentration (5-10 microM) and exposure time (45-10 microM). The PADBs were repaired rapidly in all the lymphocyte and myeloblast samples studied, with over 90% of this DNA damage being repaired within 45 min after resuspension of the cells in drug-free medium. These studies of m-AMSA in low-growth-fraction samples of human lymphocytes and myeloblasts show both similarities and differences in the action of this drug compared with previously published studies using the high-growth-fraction mouse L1210 system.

Oral complications of acute leukemia: prophylactic impact of a chlorhexidine mouth rinse regimen

The prophylactic value of twice-daily mouth rinses with a solution of 0.1% chlorhexidine gluconate in minimizing oral complications during remission-induction chemotherapy was tested in sixteen patients with acute myeloblastic leukemia. The study design was double blind with a placebo control. Standardized measurement indices were employed to assess the dental plaque levels and the degree of gingivitis and mucositis during remission-induction. The treatment group demonstrated superior oral health on the basis of each of these measurement parameters. A moderate increase in tooth staining was observed in the treatment group. The results also suggested the potential value of chlorhexidine mouth rinses in the prophylaxis of oral candidiasis in the myelosuppressed patient.

Single-strand breaks or alkali-sensitive sites in the DNA of human myeloma plasma cells and chronic lymphocytic leukemia lymphocytes

Alkaline-elution studies showed significant levels of either DNA single-strand breaks or alkali-sensitive sites in the plasma cells of six out of six myeloma patients and in the lymphocytes of two out of four patients with chronic lymphocytic leukemia as compared with normal human lymphocytes. The increased rate of DNA elution was variable from sample to sample with a range that would correspond to that observed with 100-1000 rad (1 rad = 10 mGy) of X-ray irradiation. This alteration in DNA structure was observed in both new and advanced patients, did not appear to be related to prior therapy, and did not affect the in vitro viability of these cells. Repetitive alkaline-elution profiles obtained with tumor cells from three patients were similar on subsequent samples obtained 1 month apart. Altered DNA elution was not evident in peripheral blood lymphocytes from myeloma patients with altered plasma cell DNA elution. These observations are interesting in light of the recent hypothesis that breaking and rejoining of DNA, regulated by poly(ADP-ribosyl)ation, may be a general mechanism of altering gene expression during differentiation.

A multicenter comparative trial of tobramycin and ticarcillin vs moxalactam and ticarcillin in febrile neutropenic patients

During a multicenter prospective randomized trial in febrile neutropenic patients (neutrophil count, less than 1,000/cu mm), 103 episodes were treated with tobramycin sulfate plus ticarcillin disodium (TT) while 117 were treated with moxalactam plus ticarcillin disodium (MT). The majority of patients had an underlying diagnosis of leukemia (60%) and most (62.8%) had granulocyte counts of less than 100/cu mm at the start of therapy. The response rates for clinically or microbiologically documented episodes were 38 of 60 (55.1%) for TT and 38 of 64 (59.4%) for MT. The MT regimen appeared to be more effective for gram-positive infections (56% vs 33%) while TT appeared more effective for gram-negative infections (64% vs 40%). Nephrotoxicity attributable to study drugs occurred in only 2.3% of cases (one on each treatment arm). Prolongation of the prothrombin time was observed in only six of 78 (7.7%) in the TT arm as compared with 39 of 103 (38%) in the MT arm. Neither regimen was adequate for the unusually high frequency of gram-positive pathogens seen during this study.

Origin of leukemic relapse after bone marrow transplantation detected by restriction fragment length polymorphism

Bone marrow transplantation has become an accepted modality in the treatment of acute leukemia. With this therapy, it is possible to obtain long-term disease-free survival. However, leukemia recurs occasionally. In most cases, leukemic relapse is of recipient origin. There have been several reports, though, of leukemia developing in donor cells. These cases have been limited to instances in which there is an easily identifiable chromosome difference or abnormality, usually a sex chromosome. In this paper we describe the use of restriction fragment-length polymorphism analysis to determine the origin of recurrent leukemia cells in which no identifying chromosome was present. We found that the leukemia had recurred in recipient cells. We also were able to demonstrate the presence of normal hemopoietic cells of donor origin.

Severe deficiency of B lymphocytes in peripheral blood from multiple myeloma patients

A major problem in the assessment of circulating B lymphocytes in multiple myeloma is the extent to which cells with passively absorbed Ig contribute to the assay. We have analyzed peripheral blood B cell numbers in 51 patients in various treatment categories by using an assay that is not subject to artifacts involving cytophilic Ig. We have defined a B lymphocyte by three different criteria (a) expression of a high surface density of Ig (b) expression of a high density of HLA.DR and (c) expression of a marker exclusive to surface Ig+ B cells. By these criteria, normal individuals have an average of 6% B cells. In multiple myeloma patients, B cell levels in purified mononuclear cell preparations are severely reduced. Untreated patients and the majority of patients on intermittent chemotherapy have 20-600-fold fewer B cells than do normal donors (average = 0.3%). This decrease was even greater in whole blood of patients as compared with normal donors (100-1,000-fold fewer B cells). The number of B cells did not correlate with disease status or paraprotein concentration. We found no evidence to support the idea that B lymphocytes in patients include a substantial monoclonal subset.

Aphidicolin and deoxycoformycin cause DNA breaks and cell death in unstimulated human lymphocytes

Human lymphocytes lose viability when incubated in vitro with either aphidicolin, an inhibitor of DNA polymerase alpha, or with the combination of aphidicolin and deoxycoformycin (an adenosine deaminase inhibitor). Loss of viability was assayed by vital staining with fluorescein diacetate as well as examination of Wright stained preparations and the appearance of cellular debris observed using an electronic cell counter. The loss of viability was rapid with the combination of aphidicolin (2 micrograms/ml) and deoxycoformycin (1 microgram/ml) with essentially complete loss of viability after 72 hours of incubation. This drug combination produces DNA single strand breaks after 24 and 48 hours of incubation at a level equivalent to that produced by 200 or 400R of X-irradiation, respectively.

DNA strand breaks induced in human T-lymphocytes by the combination of deoxyadenosine and deoxycoformycin

There is a progressive loss of human T-lymphocyte viability upon incubation with deoxycoformycin, an adenosine deaminase inhibitor, and low concentrations of deoxyadenosine (drug concentration that reduced cell count at 48 hr after initiation to 50% of value for untreated control culture, less than 1 microM). The loss of viability was evidenced by vital staining with fluorescein diacetate and by changes in forward single light scatter measured by flow cytometry. This loss of lymphocyte viability is detectable 18 to 20 hr after the addition of deoxyadenosine and is earlier than has been reported by other investigators using trypan blue as the vital stain. Alkaline elution studies show that the incubation of T-lymphocytes with the combinations of deoxycoformycin and deoxyadenosine gives rise to DNA single-strand breaks. These DNA strand breaks are dose and time dependent and are readily detected 4 hr after the addition of deoxyadenosine. These DNA lesions are not observed with deoxycoformycin or deoxyadenosine alone. Incubations of T-lymphocytes with deoxycoformycin and deoxyadenosine (1 and 5 microM) for 7 hr result in DNA strand breaks with a frequency of 145 and 280 rad equivalents, respectively. Preliminary studies indicate that the ability of lymphocytes to repair this damage is dependent upon deoxyadenosine concentration and exposure time. The relationship of these DNA lesions to loss of lymphocyte viability in the presence of deoxycoformycin and deoxyadenosine remains to be established.

Hemibody radiation, an active therapeutic modality for the management of patients with small cell lung cancer

In a previously published paper, the results of a preliminary clinical trial comparing systemic radiation (upper and lower hemibody technique) versus systemic chemotherapy in the management of all stages of small cell lung cancer (SCLC), suggested that hemibody radiation (HBI) was as efficient as systemic chemotherapy, particularly for patients with early disease. We are now presenting the final results of the above trial. The two year survival has shown that as many patients in the HBI as in the chemotherapy arm have reached this endpoint. However, there is a difference in favor of chemotherapy on both the median and one year survival for those patients with advanced stages. Therefore, as of June 1981, we have initiated a study incorporating HBI as a consolidating-maintenance agent for patients with all stages of the disease who have received a 3 1/2 months induction systemic chemotherapy plus local chest irradiation. Up to date, 65 patients have been entered and our median survival for those who received the complete treatment is 62.5 weeks.

The effect of anoxia on anthracycline-induced DNA damage in the RPMI-6410 human lymphoblastoid cell line

The alkaline elution procedure developed by Kohn and co-workers was used with the RPMI-6410 cultured human lymphoblastoid cell line to examine the hypothesis that anthracycline-induced DNA strand scission is mediated by oxygen- or superoxide-derived free radicals. Hypoxia was induced by gassing with nitrogen containing 5% carbon dioxide and less than 4 ppm oxygen. Alkaline elution studies showed hypoxia was induced, as the oxygen enhancement ratios for DNA strand breaks was 2.4 and 2.6 for the 250 R +/- oxygen and the 500 R +/- oxygen (1 R = 2.58 x 10(-4) C/kg) experiments, respectively. The pattern of adriamycin-induced DNA strand breaks and cross-linking was not affected by hypoxia with 1-h adriamycin exposures between 0.05 and 1.0 microgram/ml. Similarly, 1-h exposures of N-trifluoroacetyladriamycin-14-valerate at 3 or 10 micrograms/mL gave essentially identical alkaline elution profiles in the presence or absence of oxygen. These results do not support the hypothesis that oxygen-derived radicals play a primary role in anthracycline-induced DNA strand breakage.

Adenosine and deoxyadenosine toxicity in colony assay systems for human T-lymphocytes, B-lymphocytes, and granulocytes

Adenosine and deoxyadenosine toxicity was examined in colony assay systems for human T lymphocytes, B lymphocytes, and granulocytes. In the absence of deoxycoformycin, an adenosine deaminase inhibitor, no growth inhibition was observed in the three systems with concentrations of adenosine or deoxyadenosine of at least 200 microM. Deoxycoformycin itself had no growth-inhibitory effect at concentrations of at least 10 micrograms/ml. Combinations of deoxycoformycin (1 microgram/ml) and either adenosine or deoxyadenosine gave growth inhibition in all three systems. Deoxyadenosine was the most toxic in all the systems, the LD50 values being 20-25 microM. The LD50 values for adenosine were 45-55 microM. There was no evidence of selective toxicity by adenosine or deoxyadenosine with these three colony assay systems. In the T-lymphocyte colony system deoxyadenosine appeared to be toxic to both the inducer/helper and the suppressor/cytotoxic T-lymphocyte subpopulations.

Nodular mixed cell lymphoma with monoclonal gammopathy

Malignant lymphomas are rarely accompanied by a serum M component. Such neoplasms are usually of lymphocytic cell type and, with extremely rare exceptions, of diffuse pattern. A patient with an unusual malignant lymphoma of mixed cell type characterized by follicular structures and vascular proliferation was found to have a serum monoclonal gammopathy (IgM kappa) of over 4 g/dl. Remission accompanied by a pronounced reduction in the M protein was achieved with Chlorambucil. Subsequent relapse was characterized by the emergence of a large cell lymphoma with IgM kappa surface immunoglobulin. No concomitant rise in the serum M component accompanied relapse.