Ascorbic acid: a culture requirement for colony formation by mouse plasmacytoma cells.

Plasmacytoma stem cells explanted from mice formed colonies in culture only in the presence of L-ascorbic acid; this vitamin was not needed for the formation of granulocytic colonies. Isomers of L-ascorbic acid with less antiscorbutic activity also promoted plasmacytoma colony formation, but less effectively. Other redox compounds without antiscorbutic activity and an antioxidant were ineffective.

Comparison of extramedullary plasmacytomas with solitary and multiple plasma cell tumors of bone.

Patients with solitary osseous plasmacytomas (SOP) differ from those with extramedullary plasmacytomas (EMP) in that they are younger and the proportion of males is smaller. The median survival of the two groups is similar: 86.4 mo for SOP, and 100.8 mo for EMP. Progression-free survival, however, is much better for EMP. Only five EMP patients have progressed following initial radiation therapy: one developed a single bony lesion, two progressed to multiple myeloma, and two developed multiple EMP. Thus, 71% of EMP patients are progression free at 10 yr, and most deaths do not result from plasma cell neoplasia. In contrast, 13 SOP patients have progressed to develop additional osteolytic lesions, so that only 16% of SOP patients are progression free at 10 yr; death resulted from progression to multiple myeloma in most of these patients. In EMP patients the occurrence of involved lymph nodes at the time of diagnosis in seven, and initial relapse in regional nodes in three, suggest that consideration should be given to including regional lymph nodes in the radiation fields used to treat these patients.

Effect of daily etidronate on the osteolysis of multiple myeloma.

Progressive bone disease in multiple myeloma frequently leads to osteolysis, bone resorption, pathologic fractures, vertebral compression, and hypercalcemia. We conducted a double-blind study in 173 newly diagnosed multiple myeloma patients of etidronate disodium (EHDP), a diphosphonate compound that reduces bone resorption by inhibiting osteoclastic activity. The patients were randomly assigned to receive oral EHDP 5 mg/kg/d or placebo until death or discontinuation due to intolerance or refusal. The extent of vertebral deformity was measured by a vertebral index as well as height. The frequency of pathologic fractures, hypercalcemia, and bone pain was regularly assessed, as well as size and number of osteolytic lesions. All patients received melphalan and prednisone daily for 4 days every 4 weeks as the primary chemotherapy for their disease. Although the repeated measures analysis showed a significant height loss, there was no difference between treatment arms (P = .98). There was no significant difference in bone pain, episodes of hypercalcemia, or development of pathologic fractures. Patients on EHDP showed less deterioration in their vertebral index, but this difference only approached statistical significance (P = .07). We conclude that EHDP therapy used in this dosage schedule does not have a clinically significant impact in multiple myeloma.

Colony growth and self renewal of plasma cell precursors in multiple myeloma.

Culture conditions that support the growth of multi-and single-lineage hemopoietic colonies are also able to give rise to large myeloma colonies from bone marrow and peripheral blood samples of some patients with multiple myeloma. The culture system was used to determine the frequency of hemopoietic precursors and clonogenic myeloma progenitors in 71 patients with multiple myeloma studied in various clinical phases of the disease. The frequency of normal hemopoietic precursors in patients with benign monoclonal gammopathy and smoldering myeloma were indistinguishable from normal controls. Myeloma colonies were not observed in these subgroups. In contrast, patients with active disease showed significantly reduced hemopoietic colony formation, even before the initiation of therapy. A further reduction was demonstrated for patients with acute phase disease. A correlation between the frequency of hemopoietic colonies and the concentration of plasma cells in the plated sample was not observed. Large myeloma colonies with recloning potential were identified in cultures of specimens derived from 14 of the studied patients. These colonies were most frequently (ten cases) obtained from patients who had entered the acute phase of the disease. These patients manifested marrow failure (pancytopenia) and their marrow had a limited capacity to generate normal hemopoietic colonies. Three of the patients that formed myeloma colonies were studied in chronic phase following chemotherapy and one patient was examined at diagnosis. The myeloma colonies were composed exclusively of cells characterized by the same M protein as the patient. Some of the cells within the colonies retained their ability to self renew extensively, as demonstrated by serial recloning studies. Colonies derived from six of the patients are now propagated in semisolid and liquid medium for as many as nine to 34 generations. Patients that form myeloma colonies under these culture conditions represent a high-risk group with significantly shorter survival than patients not able to give rise to myeloma colonies. A Cox proportional hazards model was fitted to the data to determine the prognostic role of myeloma colony growth in culture after accounting for the influence of other well established risk factors, such as concentration of plasma cells and disease status. The analysis indicated that myeloma colony growth in culture serves as a strong and independent predictive indicator of poor clinical prognosis.

Prognostic groups for management of localized Hodgkin's disease.

Two hundred fifty-two patients receiving radical irradiation for clinical stages I and II Hodgkin's disease between 1968 to 1977 had an actuarial ten-year survival rate of 78% and a relapse-free rate of 61%. Sixty-seven patients receiving chemotherapy followed by radiation had a 78% survival rate and a 63% relapse-free rate. Independent prognostic factors for survival and relapse were age, stage, and histology. Disease bulk was predictive only of relapse. Neither site of presentation above or below the diaphragm nor presence of mediastinal involvement was predictive for survival or relapse; however, patients with large mediastinal masses (greater than or equal to 10 cm absolute diameter) had a significantly higher intrathoracic failure rate with conventional mantle irradiation. Analysis of failure, according to age, clinical stage, and histologic type, showed three groups of patients defined according to the risk of relapse with radiation therapy: those with isolated upper cervical stage IA disease (group 1, relapse rate 8%), younger patients with localized stages I and II disease of favorable histologic type (group 2, relapse rate 35%), and older patients with extensive or symptomatic stages I and II disease of less favorable histologic type (group 3, relapse rate 70%). Subsequent analysis of radiation treatment volume indicates that the use of upper abdominal irradiation for patients in group No. 2 could yield results equivalent to those achieved with radiation therapy for surgically staged patients.

Treatment of plasma cell myeloma with cytotoxic agents.

Because cross-resistance between alkylating agents has not been observed, we attempt in a prospective trial to determine the advantages, if any, in administering three alkylating agents sequentially, alternately, or concurrently. A patient with myeloma, showing progressive shortening of M-protein doubling time from 98 to 15 days, developed an acute terminal phase, characterized by fever and pancytopenia. A similar acute terminal phase was observed in 17 of 50 deaths from myeloma. Since alkylating agents are only effective in controlling the chronic phase of myeloma, future improvements will require the discovery of agents that delay, prevent, or are effective in the treatment of the acute phase. Forty-five patients with kappa- and 36 with lambda-light-chain disease showed no differences in frequency of amyloidosis, renal failure, response to treatment, or survival after treatment with alkylating agents.

Mouse myeloma. A model for studies of cell kinetics.

The mouse plasma cell tumor Adj PC-5 grows slowly due to a large loss of cells from the growth fraction into nonprolifeative, end-stage cells. All tumor cells with the capacity to form a colony appear to be in cell cycle. Marked tumor specificity of several alkylating agents could not be explaned by differences in the porliferative state of myeloma and normal marrow cells. The sensitivity of different mouse myelomas to an alkylating agent varies considerably. The factors determining whether a mouse myeloma is sensitive to an alkylating agent are probably related to structure of the agent and intrinsic properties of the cell, rather than to the agent's mechanism of action.

Radiation therapy in clinical stage I and II Hodgkin's disease. The Princess Margaret Hospital Lymphoma Group.

A review of the Princess Margaret Hospital experience over the last 20 years in treating clinically staged patients with stage I and II Hodgkin's disease was performed to analyse the impact of patient selection and extended field radiation on relapse and survival. Of the 878 patients with stage I and II Hodgkin's disease, 521 with clinical stages I and II received radiation alone as the initial treatment. The actuarial survival for all stage I and II patients was 85.1% at 5 years and 76.2% at 10 years, and for clinically staged patients treated with radiation alone, 87.2 and 77.6%, respectively. The relapse-free rate (RFR) for all clinical stage I and II patients treated with radiotherapy (RT) alone was 70.1% at 5 years and 65.8% at 10 years. Significant prognostic factors for RFR and survival included age, stage and histology. In addition, the extent of radiation was identified as an independent prognostic factor for survival as well as for relapse. The RFR for those treated with involved field RT was 58.4% at 5 years and 50.5% at 10 years; for patients treated with mantle RT, 69.9 and 65.6%, and those treated with extended field RT 77.4 and 75.8%, respectively. In a highly selected group of patients with no adverse features, i.e. with stages IA-IIA, lymphocyte predominant or nodular sclerosis histology, erythrocyte sedimentation rate < 40, age < 50, no large mediastinal mass, and no E-lesions--the policy of mantle RT (M) and extended field RT (EF) produced comparable 5-year relapse-free rates (M, 84.9%; EF, 87.1%; P = 0.53). We conclude that a policy of treatment selection based upon clinicopathological prognostic factors and the use of extended field RT confers excellent results in the treatment of clinical stage I and II Hodgkin's disease.

Interferon alfa-2b in the treatment of chronic granulocytic leukemia.

Studies of the effect of interferon on the growth of colonies of myeloid leukemic blast cells, myeloma colony-forming cells, and normal hemopoietic precursor cells have demonstrated that interferon shows no specificity in inhibiting the growth of these cells in culture (ie, growth of the malignant and normal precursor cells is equally inhibited). However, interferon markedly reduces the self-renewal capacity of acute myeloid leukemic blast cells and myeloma cells. This observation suggested that interferon's ability to prolong rather than induce remissions should be tested. We have studied the ability of interferon alfa-2b (Intron A) to prolong remissions induced by busulfan (Myleran) in patients with chronic granulocytic leukemia (CGL). The leukocyte doubling time and remission duration among patients receiving no therapy was compared with the values observed during interferon alfa-2b maintenance therapy. Nine patients have begun the study; five have completed 3 months of interferon alfa-2b therapy. In four (80%) of the five patients, there has been a significant slowing of the leukocyte doubling time and prolongation of the remission duration. A larger study, with longer follow-up, will be required to determine whether interferon alfa-2b therapy will slow progression of CGL to the blast phase and prolong survival.

Analysis of supradiaphragmatic clinical stage I and II Hodgkin's disease treated with radiation alone.

Patients with clinical Stage I and II Hodgkin's disease have been managed at the Princess Margaret Hospital for over 20 years, without the use of routine staging laparotomy. Our experience identified as adverse prognostic factors presence of a large mediastinal mass, B symptoms, and advanced age in presence of unfavorable histology (20). We had suggested previously that the use of extended field radiation therapy (XRT) was associated with a lower risk of relapse than involved field XRT or mantle XRT. There has been a trend over the past decade to select those patients with favorable prognostic factors for treatment with XRT alone and to use mantle plus upper abdominal XRT (extended field XRT) to treat them. A retrospective study of patients with clinical Stage I and II Hodgkin's disease treated at the Princess Margaret Hospital between 1978 and 1986 was conducted to determine the impact of patient selection and extended field radiation on outcome. The study involved 250 patients with supradiaphragmatic disease selected for treatment with radiation alone on the absence of adverse prognostic factors. Radiation techniques included involved field radiation in selected patients (those with upper neck involvement), mantle radiation in the earlier years, and mantle plus upper abdominal radiation in the later years of the study. Actuarial survival was 83.3% at 8 years; cause-specific survival was 90.1% and the relapse-free rate 71.6%. Local tumor control was 94.6%; only two patients had true infield failure. Multivariate analysis showed that significant prognostic factors included age, histology, and erythrocyte sedimentation rate. Extent of the radiation treatment volume was significant and influenced the risk of relapse, particularly out-of-field relapse, independently of other factors. A dose of 35 Gy was found to be sufficient for control of clinical disease. This study validated a previously developed model for the selection of clinically staged patients with Stage I and II Hodgkin's disease for treatment with radiation alone. Careful selection of these patients can yield excellent results without requiring that staging laparotomy be routinely performed or the use of systemic chemotherapy as the initial treatment.

Determination of IL6, IL1, and IL4 in the plasma of patients with multiple myeloma.

Interleukin 6 (IL6) plasma levels were measured in 63 patients with multiple myeloma and 8 individuals with benign monoclonal gammopathy. 15 of these 71 samples showed by an enzyme linked immunosorbent assay (ELISA) detectable levels that ranged from 5 to 107 pg of IL6/ml. The IL6 levels of patients with multiple myeloma did not differ significantly from those of normal individuals (N = 25, range 5-27 pg IL6/ml) (Student's t-test, p = 0.295). The samples were negative for IL4; 3 were found positive for IL1 beta. A correlation between IL6, IL4 and IL1 beta levels and disease status was not observed for this group of patients.