Late side effects of chemotherapy in ovarian carcinoma: a cytogenetic, hematologic, and statistical study

Acute Myeloblastic Leukemia after Adjuvant Chemotherapy with Melphalan in Breast Cancer. Case Report with Cytogenetic Analysis

Therapy of solid and hematologic tumors with alkylating agents appears to increase the frequency of acute non-lymphocytic leukemia (ANLL), as indicated by the cases reported in the literature. The carcinogenetic mechanism of alkylating agents seems related to their ability to damage DNA, and this is supported by the findings of multiple cytogenetic abnormalities in these patients. We report a case of ANLL secondary to therapy with melphalan, which was utilized on an adjuvant basis for breast cancer. ANLL developed 24 months after chemotherapy was discontinued. Results of the cytogenetic analysis in our patient showed multiple rearrangements and marker chromosomes. Among these was a large metacentric chromosome, identified in 6 of 8 karyotypes, in the size range of group A, which probably resulted from a translocation t(7;14) (7qter→7p11::14p11-→14qter). The natural history of the underlying disease and of the ANLL in our patient and data from chromosomal analysis seem to confirm the hypothesis that alkylating agents are potentially leukemogenic in man, probably through genetic damage. This possibility should be considered when such cytotoxic drugs are used in an adjuvant setting.

Lipid-lowering drugs and risk for cancer

The suspicion that lipid-lowering drugs might increase the risk for cancer has been present for three decades and has been the reason for intense debate and several attempts to reanalyze data from clinical trials. Recently, the results of the Simvastatin and Ezetimibe in Aortic Stenosis study sparked new interest in this problem, as the intense lipid-lowering therapy seems to have increased the number of cancers compared with the control group. This article gives an overview of the clinical evidence from trials and observational studies. As of now, the evidence is inconclusive, but there does not appear to be a reason for serious concern with short-term therapy. Whether statins and other lipid-lowering drugs will increase the risk of cancer when used over several decades is at present unknown.

Dominant lethal and heritable translocation tests with chlorambucil and melphalan in male mice

Chemicals used in the treatment of cancer include several that are potent mutagens in a range of in vitro and in vivo assays. For some, genetic effects have also been demonstrated in humans, detected as chromosomal aberrations in peripheral lymphocytes. Because (1) many of these agents are confirmed mutagens, (2) humans are exposed to them in relatively high doses, and (3) an increasing number of early cancer victims are surviving to reproductive age, it is important that information be available on the genetic and reproductive hazards associated with exposure to these agents. Chlorambucil and melphalan are structurally related chemicals that are included in our efforts to identify and assess such hazards among cancer chemotherapy agents. To date, both have been reported to induce specific locus mutations in germ cells of male mice (Russell et al., 1989; Russel et al., 1992b) and melphalan is one of very few chemicals shown to induce such mutations in spermatogonial stem cells. More recently, both chemicals were found to have strong reproductive effects in female mice (Bishop and Generoso, 1995, in preparation). In the present studies, these chemicals were tested for the induction of dominant lethal mutations and heritable translocations in male mice. Both chemicals were found to have reproductive effects attributable to cytotoxicity in specific male germ cell stages and to induce dominant lethal mutations and heritable translocations in postmeiotic germ cells, particularly in mid to early stage spermatids. Thus, relatively extensive data are now available for assessing the genetic and reproductive hazards that may result from therapeutic exposures to these chemicals.

Increased risk of second primary malignancies in patients with gynecological cancer. A Swedish record-linkage study

The Stockholm-Gotland Cancer Register was used to study the risk of developing second primary malignancies (SPM) in women diagnosed with cancer of the uterine cervix, uterine corpus and ovaries during the period 1958-1992. Among 5,325 patients with uterine cervix cancer, 619 developed SPM. Standardized incidence ratio (SIR) was 1.29 (95% confidence interval (CI) 1.19-1.39). Significantly increased risks were observed for cancer of the colon, rectum, lung, vulva, kidney and bladder. A total of 4,815 women with uterine corpus cancer were followed and 660 SPM were found. The overall SIR was 1.21 (95% CI 1.12-1.30) with significantly increased risk for cancer of the colon, ovary, vulva and bladder. The incidence of leukemia was also significantly elevated (SIR = 3.03; 95% CI 1.70-5.00). Among 5,060 patients with ovarian cancer, 379 SPM were found (SIR 1.49; 95% CI 1.34-1.64). Increased risks of cancer of the colon, rectum, breast, uterine corpus, bladder and leukemia were observed. All three primary sites showed elevated risks of cancer of the colon and bladder. For patients with a primary cancer of the corpus and ovary an elevated risk of leukemia was also noted. The conclusion from these findings is that SPM to some extent can be explained by previously known factors, i.e. treatment and common risk factors. However, further studies concerning the role of common etiology, for instance hereditary and hormonal factors, are needed to increase the knowledge on the etiology of second primary malignancies.

Sister-chromatid exchange: second report of the Gene-Tox Program

This paper reviews the ability of a number of chemicals to induce sister-chromatid exchanges (SCEs). The SCE data for animal cells in vivo and in vitro, and human cells in vitro are presented in 6 tables according to their relative effectiveness. A seventh table summarizes what is known about the effects of specific chemicals on SCEs for humans exposed in vivo. The data support the concept that SCEs provide a useful indication of exposure, although the mechanism and biological significance of SCE formation still remain to be elucidated.

Cytogenetic findings in 111 ovarian cancer patients: therapy-related chromosome aberrations and heterochromatic variants

The chromosomes of 111 ovarian cancer patients were studied in G- and C-banded slides from peripheral blood lymphocyte (PBL) cultures for chromosome damage caused by chemotherapy and radiotherapy and for asymmetry of the constitutive heterochromatin of chromosomes 1, 9, and 16. We also monitored the survival of these patients to determine whether any secondary neoplasia induced by the therapy and report the findings of our investigations. Melphalan (MEL) was the only drug used in single-drug chemotherapy. The incidence of chromosome abnormalities in melphalan-treated cells (25%) was higher than in the control group (17%). The incidence of structural changes was also higher (10.5%) in the MEL-treated group than in controls (6%). After treatments with combinations of drugs, the incidence of structural changes remained at the same level (11%). In the patients receiving combined treatment with MEL and radiation, the rate of structural changes increased dramatically (24%). The overall rate of chromosome aberrations in this group was also higher (50%). Combination of two or more drugs and radiation produced only 14% structural chromosome changes. The overall rate of chromosome aberrations was also low (20%) in this group. Of 111 patients studied, only 33 were alive 6 years after initiation of the study. Of the surviving patients, eight had rearranged chromosomes in the first analysis. After 5 years, new blood samples were collected from these patients and chromosome analyses showed abnormal karyotypes in all eight patients. All chromosome abnormalities in the second analysis were completely unrelated to those in the first analysis, however. Whether the chromosome changes in the second analysis were due to therapy or to other unknown factors could not be determined. Data on C-banding and the distribution of inversions indicated that 91% of the patients had C-band heteromorphisms of chromosomes 1, 91% had heteromorphisms of chromosome 9, and 69% had heteromorphisms of chromosome 16. Furthermore, inversions were observed in chromosome 1 (41% of patients), chromosome 9 (28% of patients), and chromosome 16 (5% of patients).

The frequency of translocations after treatment for Hodgkin's disease

We studied the frequency of translocations in peripheral blood lymphocytes of patients with Hodgkin's disease to determine the extent of chromosome changes induced by radiation or radiation and chemotherapy. Comparisons were made to patients with second cancers to determine if this population is more susceptible to the effects of treatment. Group one included six patients with newly diagnosed Hodgkin's disease who were treated with radiation only. Group two included Hodgkin's disease patients who were treated 12-24 years previously and have been continuously free of disease. Five of these patients were treated with radiation only and five patients received radiation and mechlorethaminehydrochloride, oncovin, procarbazine, prednisone (MOPP) chemotherapy for six cycles. Group three included three patients who developed a second cancer after successful treatment for Hodgkin's disease. Two of these patients had a sarcoma within the radiation field and one had breast cancer. Metaphase spreads were obtained from cultured lymphocytes and hybridized with a chromosome 4 specific probe. After fluorescein staining, approximately 1000 metaphases were scored per patient. In group one only one patient in six demonstrated translocations in chromosome 4 before treatment for a mean frequency of .0009. After treatment the frequency of translocations increased to a mean of .016 (p = .036) (range .006-.034). Group two patients treated with radiation only had a mean translocation frequency of .012 (range .004-.022) in comparison to the radiation/mechlorethaminehydrochloride, oncovin, procarbazine, prednisone chemotherapy treated patients who demonstrated a mean frequency of .016 (p = .425) (range .0009-.023). The third group of second cancer patients showed inconsistent translocation frequencies of .002, .020, and .035. Of these patients, the one who demonstrated the greatest frequency of translocations (.035) was treated with mechlorethaminehydrochloride, oncovin, procarbazine, prednisone/adriamycin, bleomycin, vinblastine, decadron) and radiation. Our data demonstrates a statistically significant increase in translocations detected after radiation. When compared to combined modality therapy a greater mean frequency of translocations is observed over radiation alone; however, this was not statistically significant. In the three patients who developed second cancers in our series we saw no consistent increase in translocation frequency compared to Hodgkin's disease patients who did not develop a second cancer.

Chronic myelogenous leukemia after treatment with 131I for thyroid carcinoma. Report of a case and review of the literature

A patient who developed Philadelphia chromosome-positive chronic myelogenous leukemia (CML) 5 years after successful treatment for thyroid carcinoma, is reported. The Philadelphia chromosome was the typical 9;22 translocation. Southern blot analysis showed breakpoint cluster region rearrangement as observed in classical CML. Up to now, only two cases of CML have been reported following treatment for thyroid carcinoma. This rare complication has also been described after therapy for other malignancies. At present, it is not clear whether the development of CML after thyroid carcinoma represents a therapy-induced complication, a coincidence, or an increased susceptibility to secondary malignancies due to the malignant process itself.

Persistence of cytogenetic damage induced by alkylating antineoplastic drug phopurinum in human lymphocytes in vivo and in vitro

Sister chromatid exchanges (SCEs) and structural chromosome aberrations (CAs) induced by cytostatic drug phopurinum in vivo and in vitro were studied in human lymphocytes. Phopurinum was found to cause a significant increase of CAs in lymphocytes of patients undergoing cytostatic therapy. Increased CA rates, however, declined rapidly after the cessation of treatment. This decline observed in vivo is in agreement with experimental results obtained in vitro, where it is found that the induction of SCEs and CAs occur only during the 1st cell cycle after pulse-treatment as G1 stage with phopurinum. Thus, phopurinum induced short-lived DNA damage both experimentally and in vivo.

Therapeutic and metabolic effects of high (greater than 1 g/m2) systemic cumulative doses of cis-platinum in patients with ovarian carcinoma

Adverse effects requiring discontinuation of cis-platinum therapy are usually noted after administration of 600 mg/m2 cis-platinum. Metabolic and therapeutic effects of high (greater than 1 g/m2) cumulative lifetime doses of cis-platinum were reviewed for 20 patients treated with multiple courses of chemotherapy for metastatic, recurrent ovarian carcinoma. Median survival in this selected group is 65 months. Common abnormalities included anemia, hypomagnesemia, and elevated renal functions. No patient required cessation of treatment because of metabolic changes and in no case did the abnormality compromise the patient's activities of daily living. We conclude that, in selected patients, repeated treatment, regardless of cumulative dose, with cis-platinum-based chemotherapy can be well tolerated and may be of therapeutic benefit.

Leukemia following chemotherapy for ovarian cancer

An international collaborative group of cancer registries and hospitals identified 114 cases of leukemia following ovarian cancer. We investigated the possible etiologic role of chemotherapy, radiotherapy, and other factors, using a case-control study design, with three controls matched to each case of leukemia. Chemotherapy alone was associated with a relative risk of 12 (95 percent confidence interval, 4.4 to 32), as compared with surgery alone, and patients treated with both chemotherapy and radiotherapy had a relative risk of 10 (95 percent confidence interval, 3.4 to 28). Radiotherapy alone did not produce a significant increase in risk as compared with surgery alone. The risk of leukemia was greatest four or five years after chemotherapy began, and the risk was elevated for at least eight years after the cessation of chemotherapy. The drugs cyclophosphamide, chlorambucil, melphalan, thiotepa, and treosulfan were independently associated with significantly increased risks of leukemia, as was the combination of doxorubicin hydrochloride and cisplatin. Chlorambucil and melphalan were the most leukemogenic drugs, followed by thiotepa; cyclophosphamide and treosulfan were the weakest leukemogens, and the effect per gram was substantially lower at high doses than at lower doses. The extent to which the relative risks of leukemia are offset by differences in chemotherapeutic effectiveness is not known.

Long-term cytogenetic effects of antineoplastic treatment in relation to secondary leukemia

Chromosome translocations are consistently present in leukemias and lymphomas and are likely to represent primary events in the development of these neoplasias. A study of conditions that predispose to leukemia could shed some light on the origin of these translocations and therefore help in clarifying their exact role in the process of neoplastic transformation. Based on this assumption, we studied a group of individuals treated with radiochemotherapy for previous lymphoma and who were at increased risk of developing a secondary leukemia. The group comprised 14 Hodgkin's disease patients, 11 non-Hodgkin's lymphoma patients, and 13 controls. The patients were in remission and had been off therapy for at least 6 months. Chromosomes were studied from phytohemagglutinin (PHA)-stimulated peripheral lymphocytes and from bone marrow cells by the direct method and after short-term cultures (72 hours). The latter were also exposed to 5-bromodeoxyuridine (BrdU). Metaphases were scored for chromosome breaks, gaps, and other rearrangements. The percentage of gaps and breaks was significantly higher in patients than in controls. The difference was induced by BrdU and was apparent in bone marrow cells, but not in peripheral lymphocytes. We conclude that individuals exposed to the action of mutagenic agents (radiochemotherapy) have an increased chromosome instability that could be related to their increased risk of developing a secondary leukemia.

Solid tumours and chromosome aberrations as late side effects of melphalan therapy in ovarian carcinoma

Fifty-five ovarian cancer patients treated with melphalan during 1968-1978 were followed during 309 person years and studied with cytogenetic analyses. During the clinical follow-up 7 patients developed a new primary solid tumour. The excess risk of developing new primary solid tumours in patients treated with melphalan was statistically significant (p less than 0.05) and the relative risk corresponded to 3.0. Patients developing a new solid tumour showed a similar pattern of chromosome aberrations in the peripheral lymphocytes to that previously shown for the whole cohort.

Risk of leukaemia in ovarian tumour and breast cancer patients following treatment by cyclophosphamide

A case-control study was conducted to determine whether the development of leukaemia was associated with chemotherapy for neoplasms of the ovary or breast, in a population where most such chemotherapy consisted of cyclophosphamide alone. Cases and controls were identified from the National Cancer Registry of the German Democratic Republic. Cases were women who had developed leukaemia as a second primary after an initial diagnosis, at least one year before, of an ovarian or breast tumour. Controls were patients with an ovarian tumour or breast cancer who had survived to the year when the case developed a leukaemia but who had not themselves developed a second malignancy. Controls were matched to cases by the site of the first primary and its year of diagnosis, as well as year of birth. The relative risk for acute leukaemia following treatment with cyclophosphamide alone was significantly elevated (P less than 0.05), at 14.6 for ovarian tumour patients and 2.7 for breast cancer patients. Among breast cancer patients the increased risk of leukaemia associated with chemotherapy was confined to women who had been under 50 years of age at the time of diagnosis of the breast cancer (for whom the relative risk was 13.1). No excess risk of leukaemia was observed in association with radiotherapy for either ovarian or breast cancer patients. The present findings strongly suggest that cyclophosphamide as a single chemotherapeutic agent is capable of inducing leukaemia in humans.

Long-term effects of chemotherapy on lymphocyte chromosomes from patients treated for gestational trophoblastic tumours

A cytogenetic follow-up study of patients treated with chemotherapy for gestational trophoblastic tumours was undertaken. In some cases, high levels of chromosome damage were found to persist in lymphocytes for several years after completion of therapy. These results are compared with those found in similar studies of non-malignant and other malignant diseases. The relevance of these findings to the risk of subsequent chemotherapy-induced malignancy is discussed.

Occupational exposure to anticancer drug--potential and real hazards

Many anticancer agents have been shown to be mutagenic, teratogenic and carcinogenic in experimental systems and second malignancies are known to be associated with several specific therapeutic treatments. Anticancer agents thus represent a class of occupational carcinogens, the handling of which should involve no unnecessary exposure. The available methodologies to detect possible exposures from ambient air and from biological samples are discussed, and the published data on results are reviewed. Analytical methods are available for the detection of most frequently used anticancer drugs from all groups, i.e., alkylating agents, mitotic inhibitors, antimetabolites and antibiotics. The ambient samples taken from sites of admixture of cytostatics have often shown detectable, but low concentrations of anticancer agents. Urine samples from patients under chemotherapy as well as from personnel handling the drugs occupationally in hospitals have been analyzed both chemically and for excreted mutagenicity. Both cisplatin and cyclophosphamide have been detected in the urine of patients; furthermore, cyclophosphamide was observed in the urine of nurses who formulate and deliver this drug. Urinary mutagenicity assays have given both positive and negative results in various groups of nursing and pharmacy personnel. Cytogenetic methods have, likewise, been applied for monitoring purposes. Most of the available data concerns chromosome aberrations (CA) or sister-chromatid exchanges (SCE) induced in peripheral blood lymphocytes of patients under chemotherapy. A few studies on groups occupationally exposed to anticancer drugs have given positive results, but also negative reports have appeared for these same cytogenetic parameters. No studies are as yet available on the possible carcinogenic effects of occupational handling of anticancer drugs. Two recent case-referent studies among hospital personnel have pointed to slightly increased risks of disorders in pregnancy outcome; one of the studies has shown an excess of spontaneous abortions and other malformations in children of females with a history of work with anticancer agents.

Unequal sister chromatid exchange. A mechanism affecting Ig gene arrangement and expression

Two gamma 2a gene forms in the MPC11 mouse myeloma cell line (gamma 2b, K) have been localized to the expressed H chain chromosome, where they exist in tandem downstream of the expressed gamma 2b gene. The gamma 2a gene duplication has apparently occurred by spontaneous, unequal sister chromatid exchange (SCE) in a B lymphoid precursor of MPC11 or in MPC11 itself. It is especially significant that either of the tandem gamma 2a gene forms may be used in the class switch from gamma 2b to gamma 2a production occurring in the MPC11 line, indicating that heavy chain constant region (CH) gene duplication (or deletion) may be a mechanism normally impinging on CH gene expression. The gamma 2a genes of MPC11 undergo further copy number variation via unequal SCE in variants of this line derived by mutagenesis and selection for altered H chain production. The remarkable frequency with which copy number variation occurs in these cells suggests that unequal SCE may play a physiological role in CH gene arrangement and expression.

Ovarian carcinoma. A decade of progress

Significant and dramatic progress has been made in the diagnosis and treatment of women with ovarian carcinoma in the last 10 years, the results of which are now just being reflected in an increase in survival and cure rates. In early staged disease (Stage I and II) significant progress has been made concerning our understanding of the sites of subclinical metastasis when at surgery the tumor is clinically limited to the ovary or pelvis. A prospective study of 100 patients with Stages IA to IIB ovarian cancer who underwent restaging within 4 weeks of initial surgery will report this. Moreover, preliminary results of the first randomized therapeutic trials (melphalan versus observation; melphalan versus chromic phosphate [P-32]) in patients surgically staged and found to be Stage IA to IIB carcinoma will be discussed. For Stages IB to III, the 5-year survival rates comparing whole abdominal radiation by the moving strip technique to open field irradiation will be discussed. For advanced (Stage III and IV) ovarian carcinoma, the new techniques in debulking surgery will be illustrated. Finally, the significant progress in response rates, median duration of survival, disease-free survival, and 5-year survival rates made during the past 10 years will be presented. This will be done by comparing a unique group of 117 patients treated with melphalan alone, all of whom have been followed for 5 years or until death, to patients who received cisplatin combination chemotherapy--cyclophosphamide, hexamethylmelamine, Adriamycin (doxorubicin), and cisplatin (CHAD) or cisplatin, Adriamycin, and cyclophosphamide (PAC)--and have now been followed 3.4+ and 4+ years, respectively. What is clearly evident is that in the last decade there has been significant increase in response rates, median duration of survival, 3.4+-, 4+-, and 5-year survival rates and cure rates with the advent of debulking surgery and platinum-containing combination chemotherapy.

Persistence of chromosome rearrangements in peripheral lymphocytes from patients treated with melphalan for ovarian carcinoma

Chromosome aberrations were studied in peripheral lymphocytes from 50 patients treated with melphalan against ovarian carcinoma. The chromosome analyses were carried out 4-132 months (mean 57 months) after the end of melphalan therapy. Most of the patients were studied several times during four years. The mean frequency of cells with chromosome and chromatid aberrations was 5.4% in the patients and 2.3% in an untreated control group. The highest aberration frequency (average 18%) was found in a patient who later developed gastric carcinoma. The dominating types of aberrations in the patients were chromosome exchanges occurring as single marker chromosomes or as multiple chromosome rearrangements. These types of aberrations were found in only 0.3% of the control cells as compared to 3.8% of the patient cells. Patients with a high total dose of melphalan (above 420 mg) and a long duration of the therapy (average 22.5 months) had a higher frequency of cells with aberrations (6.3%) than patients with a lower total dose (below 420 mg) and a shorter therapy (12 months) (4.2%). No additive effect of radiation therapy was observed on the aberration frequency.

Leukemia and preleukemia after adjuvant treatment of gastrointestinal cancer with semustine (methyl-CCNU)

We evaluated the risk of acute nonlymphocytic leukemia, acute myelodysplastic syndrome, and preleukemia in 3633 patients with gastrointestinal cancer who were treated in nine randomized clinical trials. Among 2067 patients given semustine (methyl-CCNU) as adjuvant therapy, leukemic disorders developed in 14, whereas only one leukemic disorder (acute nonlymphocytic leukemia) occurred among 1566 patients given other therapies (relative risk = 12.4; 95 per cent confidence interval = 1.7 to 250). The six-year cumulative mean risk (+/- S.E.) of acquiring a leukemic disorder after treatment with semustine was 4.0 +/- 2.2 per cent; the incidence rate was 2.3 cases per 1000 persons per year. Risk increased significantly with time after treatment. The risk of leukemic disorders did not differ according to sex, race, age at treatment, or initial tumor type, nor was it enhanced by concomitant radiotherapy or immunotherapy. In addition, no excess of acute nonlymphocytic leukemia was seen in 44,370 patients treated for gastrointestinal cancer in Connecticut during the period 1935 to 1974, before the advent of nitrosourea chemotherapy. This study provides quantitative evidence that nitrosoureas are leukemogenic in human beings and confirms previous observations that adjuvant chemotherapy with alkylating agents may increase the risk of leukemia.

DNA and chromosome alterations in lymphocytes of operating room personnel and in patients before and after inhalation anaesthesia

In order to evaluate the possible genotoxic effects of inhalation anaesthetics, the frequency of sister chromatid exchanges and chromosome aberrations was studied in peripheral lymphocytes of control subjects, operating room personnel and patients before and after inhalation anaesthesia during orthopaedic operations. In the patients, the frequency of DNA breaks was studied as well. None of the genotoxic parameters showed an increase which could be related to anaesthetic exposure. The frequency of sister chromatid exchange was very similar in the control and personnel groups, as well as in patients before and after operation. The frequency of chromosome aberrations was unusually low in the control group, whereas the personnel and patient groups showed normal levels of chromosome aberrations which did not differ from previously studied control groups. There was no statistical difference in the frequency of chromosome aberrations or DNA breaks in the patient group after, as compared to before, operation. Smokers were found to have a significantly increased frequency of chromosome gaps compared to nonsmokers, but there was no indication that this difference was related to anaesthetic exposure. The data presented give no indications of genotoxic effects in vivo of inhalation anaesthetics by either occupational exposure to waste anaesthetic gases, or anaesthesia during operation. On the other hand, our present data do not contradict previous data indicating that hospital personnel, irrespective of exposure to inhalation anaesthetics, may have a small average increase of chromosome abnormalities.