Jens Pedersen-Bjergaard

Increased risk of myelodysplasia and leukaemia after etoposide, cisplatin, and bleomycin for germ-cell tumours

Among the cytostatic drugs only the alkylating agents have been firmly established as being leukaemogenic. This report describes 4 cases of acute myeloid leukaemia and 1 of myelodysplasia occurring in a cohort of 212 patients with germ-cell tumours treated with etoposide, cisplatin, and bleomycin. The mean cumulative risk of leukaemic complications was 4.7% (SE 2.3) 5.7 years after start of etoposide-containing chemotherapy, and, compared with the risk in the general population, the relative risk of overt leukaemia was 336 (95% CI 92-861). No leukaemias were detected in a previous cohort of 127 patients with germ-cell tumours treated with cisplatin, bleomycin, and vinblastine. The increased risk of leukaemia was most probably due to etoposide alone or in combination with cisplatin or bleomycin, since other published work has also not revealed an excess of leukaemias among patients with germ-cell tumours treated with only cisplatin, bleomycin, and vinblastine. The risk of leukaemia was dose related since all 5 patients with leukaemic complications were among the 82 who had received a cumulative dose of more than 2000 mg/m2 etoposide, whereas no leukaemias were observed among 130 patients who had received up to 2000 mg/m2 (p = 0.004). 3 of the leukaemic patients had balanced chromosome translocations affecting bands 11q23 and 21q22. These translocations, and perhaps also other balanced aberrations, seem to be characteristic of myelodysplasia and acute leukaemia occurring after therapy with cytostatic agents acting on DNA-topoisomerase II.

Mutations With Loss of Heterozygosity of p53 Are Common in Therapy-Related Myelodysplasia and Acute Myeloid Leukemia After Exposure to Alkylating Agents and Significantly Associated With Deletion or Loss of 5q, a Complex Karyotype, and a Poor Prognosis

PURPOSE To study mutations and loss of heterozygosity (LOH) of p53 in therapy-related myelodysplasia (t-MDS) and acute myeloid leukemia (t-AML). PATIENTS AND METHODS Fifty-two unselected patients with t-MDS and 25 patients with t-AML were studied by polymerase chain reaction (PCR)-single-strand conformational polymorphism (SSCP) at the DNA level and by reverse transcriptase (RT)-PCR-SSCP at the mRNA level, and cases with aberrant SSCP patterns were sequenced. RESULTS Somatically acquired mutations of p53 were observed in 21 of 77 cases of t-MDS or t-AML, and 19 of these 21 patients had received alkylating agents. Single-base substitutions at A:T pairs were more common in t-MDS and t-AML, whereas single-base substitutions at G:C pairs are most common in MDS and AML de novo and in solid tumors. Six patients demonstrated a cytogenetic loss of 17p13, and these six and an additional nine patients with p53 mutations demonstrated LOH of p53 at the DNA or mRNA level. This suggests a cytogenetic loss of the normal p53 allele in these nine cases combined with duplication of the homologous chromosome 17 carrying the mutated p53 allele. Mutations of p53 were significantly associated with deletion or loss of 5q (P <.0001) and a complex karyotype (P =.0001), but surprisingly were not associated with deletion or loss of 7q (P =.73), and were infrequent in patients with balanced chromosome translocations (P =.03). Mutations of p53 were more common in older patients (P =.036) and were associated with an extremely poor prognosis (P =.014), apparently restricted to the 15 cases with LOH of p53 ( P =.046). CONCLUSION Mutations with loss of function of p53 are significantly associated with deletion or loss of 5q in t-MDS and t-AML after previous treatment with alkylating agents and are associated with genetic instability.

Risk of acute nonlymphocytic leukemia and preleukemia in patients treated with cyclophosphamide for non-Hodgkin's lymphomas. Comparison with results obtained in patients treated for Hodgkin's disease and ovarian carcinoma with other alkylating agents.

Of 602 patients treated for non-Hodgkins lymphomas, 9 developed overt acute nonlymphocytic leukemia or preleukemia with refractory cytopenia and cytogenetic abnormalities of the bone marrow. A Kaplan-Meier estimate of the cumulative probability of leukemic complications was 6.3 +/- 2.6% (mean +/- SE) 7 years after start of treatment. All 9 patients with leukemic complications belong to a major subgroup of 498 patients treated with alkylating agents, predominantly cyclophosphamide. The risk of leukemic complications in this subgroup was compared with the risk in 312 patients treated with other alkylating agents for Hodgkins disease, and with the risk in 553 patients treated with dihydroxybusulfan for ovarian carcinoma. Cumulative 9-year risks were 8.0 +/- 3.3%, 12.8 +/- 3.5%, and 7.1 +/- 1.9%, respectively. The general risk of secondary leukemia after long-term treatment with alkylating agents ranges from 1% to 1.5% per year from 2 to at least 9 years after start of treatment.

A randomized study of radiotherapy versus radiotherapy plus chemotherapy in stage I-II non-hodgkin's lymphomas

In a randomized, prospective trial from 1974–1978, 73 patients with non‐Hodgkins lymphomas in clinical Stage I or II were treated with extended field radiotherapy alone (RT) or RT plus adjuvant chemotherapy with vincristine, streptonigrin, cyclophosphamide and prednisone (RT + CT). With a median follow‐up time of five years, 54% have relapsed in the RT group versus only 10% in the RT + CT group (P < 0.01). There is no statistical difference in the overall survival yet, but 13/14 deaths in the RT group versus only 3/12 in the RT + CT group were due to progressive disease. Among patients with unfavorable histology, 13/22 in the RT group have died from disease progression against 3/34 in the RT + CT group (P < 0.01). The results are in agreement with those from two other series published in detail. Based on these results we therefore recommend to use adjuvant CT with RT in all Stage I‐II patients with unfavorable histology. Further observation is necessary before a conclusion can be drawn for the lymphoma patients with more favorable histology. Cancer 52:1–7, 1983.

RISK OF THERAPY-RELATED LEUKAEMIA AND PRELEUKAEMIA AFTER HODGKIN'S DISEASE: Relation to Age, Cumulative Dose of Alkylating Agents, and Time from Chemotherapy

391 patients treated intensively for Hodgkins disease were followed for up to 15 years to evaluate the risk of therapy-related acute non-lymphocytic leukaemia (t-ANLL) and preleukaemia. Only two independent factors, patient age and cumulative dose of alkylating agents, were related to the risk of t-ANLL. The hazard rate of t-ANLL was roughly proportional to the square of patient age and to the total cumulative dose of alkylating agents. In 320 patients treated with alkylating agents the cumulative risk of t-ANLL increased steadily from 1 year after the start of treatment and reached 13.0% (SE 3.0) at 10 years after which time there were no further cases. Calculated from cessation of therapy with alkylating agents, however, the cumulative risk curve increased steeply during the first 1-2 years then gradually levelled out and no new cases were observed beyond 7 years. With a 15-year follow-up the general risk of solid tumours was not increased.

Genetics of therapy-related myelodysplasia and acute myeloid leukemia

Myelodysplasia (MDS) and acute myeloid leukemia (AML) are heterogeneous, closely associated diseases arising de novo or following chemotherapy with alkylating agents, topoisomerase II inhibitors, or after radiotherapy. Whereas de novo MDS and AML are almost always subclassified according to cytogenetic characteristics, therapy-related MDS (t-MDS) and therapy-related AML (t-AML) are often considered as separate entities and are not subdivided. Alternative genetic pathways were previously proposed in t-MDS and t-AML based on cytogenetic characteristics. An increasing number of gene mutations are now observed to cluster differently in these pathways with an identical pattern in de novo and in t-MDS and t-AML. An association is observed between activating mutations of genes in the tyrosine kinase RAS–BRAF signal-transduction pathway (Class I mutations) and inactivating mutations of genes encoding hematopoietic transcription factors (Class II mutations). Point mutations of AML1 and RAS seem to cooperate and predispose to progression from t-MDS to t-AML. Recently, critical genetic effects underlying 5q−/−5 and 7q−/−7 have been proposed. Their association and cooperation with point mutations of p53 and AML1, respectively, extend the scenario of cooperating genetic abnormalities in MDS and AML. As de novo and t-MDS and t-AML are biologically identical diseases, they ought to be subclassified and treated similarly.

Carcinoma of the Urinary Bladder after Treatment with Cyclophosphamide for Non-Hodgkin's Lymphoma

Abstract We observed nine cases of transitional-cell carcinoma of the urinary bladder among patients who had had long-term treatment of other cancers with cyclophosphamide. Seven of the bladder carcinomas occurred within a cohort of 471 patients treated for non-Hodgkins lymphomas. In this cohort the relative risk of bladder cancer was 6.8 (95 percent confidence interval, 3.2 to 14.2). The cumulative risk (mean±SE) was 3.5±1.8 percent 8 years after the start of treatment with cyclophosphamide and 10.7±4.9 percent after 12 years. Three of the nine patients were 50 years of age or younger; seven died with progressive bladder cancer. Subsequently, an additional patient had acute nonlymphocytic leukemia. Hemorrhagic cystitis was observed in 33 patients (cumulative risk, 11.8±2.1 percent after five years). Development of carcinoma of the urinary bladder was not related to previous hemorrhagic cystitis. The results caution against long-term treatment with cyclophosphamide for diseases with a favorable prognosis...

Methylation of p15INK4B is common, is associated with deletion of genes on chromosome arm 7q and predicts a poor prognosis in therapy-related myelodysplasia and acute myeloid leukemia

The p14ARF, p15INK4B, and p16INK4A genes are important negative cell-cycle regulators often inactivated by deletions, mutations, or hypermethylation in malignancy. Hypermethylation of the three genes was studied in 81 patients with therapy-related myelodysplasia (t-MDS) or acute myeloid leukemia (t-AML) by methylation-specific PCR, and p15 methylation additionally by bisulfite genomic sequencing. In all, 55 patients disclosed p15 methylation, five patients showed p16 methylation, whereas p14 methylation was not observed. Methylation of p15 was closely associated with deletion or loss of chromosome arm 7q (P=0.0006). In t-MDS, the p15 methylation frequency and the p15 methylation density both increased significantly by stage (P=0.004 and 0.0002), and p15 methylation frequency increased with an increasing percentage of myeloblasts in the bone marrow (P=0.006). In a two-variable Cox model including the percentage of myeloblasts, p15 methylation was an independent prognostic factor (P=0.005). Methylation of p15 was less common in t-AML of subtype M5 than in other FAB subtypes (P=0.03). Methylation of p15 was unrelated to type of previous therapy, to latent period from start of therapy, to platelet count, and to p53 mutations. Inactivation of p15 and deletion of genes on chromosome arm 7q possibly cooperate in leukemogenesis.

Acute nonlymphocytic leukemia, preleukemia, and acute myeloproliferative syndrome secondary to treatment of other malignant diseases. II. Bone marrow cytology, cytogenetics, results of HLA typing, response to antileukemic chemotherapy, and survival in a total series of 55 patients

Secondary acute nonlymphocytic leukemia or its earlier stages, preleukemia or an acute myeloproliferative syndrome with refractory cytopenia and clonal cytogenetic abnormalities of the bone marrow, was diagnosed in 55 patients previously treated for other malignant diseases. In patients with overt leukemia, cytologic, and cytochemical studies showed predominance of the French–American–British (FAB) type M2. Cytogenetic examination demonstrated a normal karyotype in 11 cases, whereas clonal abnormalities were observed in 44 patients. Defects of chromosome 7 were observed in 24 cases, most often –7, and defects of chromosome 5 in 14 cases, most often 5q–. In addition, chromosomes 3 and 17 were possibly nonrandomly involved. Other abnormalities commonly observed in de novo acute nonlymphocytic leukemia as t(8;21) and t(15;17) were not observed and +8 rarely seen in secondary leukemia. The survival from the leukemic complication was short for the whole group of 55 patients (median, 7 months). However, a significantly longer survival was observed in a subgroup of 11 patients with a normal karyotype (P < 0.01), due to a favorable response to antileukemic chemotherapy, and in a subgroup of 11 patients with −7 or −C as the only cytogenetic abnormality (P < 0.01), due to a prolonged preleukemic phase, compared with the remaining 33 cases with mostly multiple karyotypic abnormalities. Three preleukemic patients with −7 who were studied during transformation to overt leukemia all developed additional cytogenetic abnormalities. According to the two‐step or multistep hypothesis for malignant transformation, the prolonged preleukemic course in patients with −7 as the only abnormality could represent a premalignant stage, in which further evolution is required for development of overt leukemia. The patients showed a random distribution of blood groups and HLA types.

Alternative genetic pathways and cooperating genetic abnormalities in the pathogenesis of therapy-related myelodysplasia and acute myeloid leukemia

Alternative genetic pathways were previously outlined in the pathogenesis of therapy-related myelodysplasia (t-MDS) and acute myeloid leukemia (t-AML) based on cytogenetic characteristics. Some of the chromosome aberrations, the recurrent balanced translocations or inversions, directly result in chimeric rearrangement of genes for hematopoietic transcription factors (class II mutations) which disturb cellular differentiation. Other genetic abnormalities in t-MDS and t-AML comprise activating point mutations or internal tandem duplications of genes involved in signal transduction as tyrosine kinase receptors or genes more downstream in the RAS-BRAF pathway (class I mutations). The alternative genetic pathways of t-MDS and t-AML can now be further characterized by a different clustering of six individual class I mutations and mutations of AML1 and p53 in the various pathways. In addition, there is a significant association between class I and class II mutations possibly indicating cooperation in leukemogenesis, and between mutations of AML1 and RAS related to subsequent progression from t-MDS to t-AML. Therapy-related and de novo myelodysplasia and acute myeloid leukemia seem to share genetic pathways, and surprisingly gene mutations were in general not more frequent in patients with t-MDS or t-AML as compared to similar cases of de novo MDS and AML studied previously.