Temozolomide may induce therapy-related acute lymphoblastic leukaemia

Lymphoproliferative disorder during temozolomide therapy; a representative case of a formidable complication and management challenges

BACKGROUND

Lymphoproliferative disorder represents a heterogeneous clinicopathological spectrum characterized by uncontrolled proliferation of lymphocytes. Immunodeficiency is a major trigger of its development. While induction of immunodeficiency is a well-known adverse effect of temozolomide therapy, development of lymphoproliferative disorder following temozolomide therapy has not previously been described.

CASE PRESENTATION

A patient with brainstem glioma developed constitutional symptoms, pancytopenia, splenomegaly and generalized lymphadenopathy during the 2nd cycle of maintenance therapy following induction therapy with temozolomide. Epstein-Barr virus-infected lymphocytes were observed histopathologically and "other iatrogenic immunodeficiency-associated lymphoproliferative disorder" (OIIA-LPD) was diagnosed. Although discontinuation of temozolomide led to rapid remission, relapse was observed 4 months later. CHOP chemotherapy was induced, resulting in secondary remission. Vigilant follow-up for another 14 months showed radiologically stable brainstem glioma and no further recurrence of OIIA-LPD.

CONCLUSIONS

This is the first report documenting OIIA-LPD during temozolomide administration. Timely diagnosis of the disease and discontinuation of the causative agent were considered to be the management of choice. Close monitoring for relapse should be continued. Finding a balance between glioma management and controlling the remission of OIIA-LPD remains to be clarified.

Unboxing the molecular modalities of mutagens in cancer

The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage induced by such mutagens is the initial step in the process of carcinogenesis resulting in the accumulation of mutations. Mutational events are considered the major triggers for introducing genetic and epigenetic insults such as DNA crosslinks, single- and double-strand DNA breaks, formation of DNA adducts, mismatched bases, modification in histones, DNA methylation, and microRNA alterations. However, DNA repair mechanisms are devoted to protect the DNA to ensure genetic stability, any aberrations in these calibrated mechanisms provoke cancer occurrence. Comprehensive knowledge of the type of mutagens and carcinogens and the influence of these agents in DNA damage and cancer induction is crucial to develop rational anticancer strategies. This review delineated the molecular mechanism of DNA damage and the repair pathways to provide a deep understanding of the molecular basis of mutagenicity and carcinogenicity. A relationship between DNA adduct formation and cancer incidence has also been summarized. The mechanistic basis of inflammatory response and oxidative damage triggered by mutagens in tumorigenesis has also been highlighted. We elucidated the interesting interplay between DNA damage response and immune system mechanisms. We addressed the current understanding of DNA repair targeted therapies and DNA damaging chemotherapeutic agents for cancer treatment and discussed how antiviral agents, anti-inflammatory drugs, and immunotherapeutic agents combined with traditional approaches lay the foundations for future cancer therapies.

Temozolomide duration and secondary hematological neoplasms: A literature review and implications for patients with neuroendocrine neoplasms

Evidence-based recommendations for the optimal duration and sequencing of temozolomide-based treatments in advanced neuroendocrine neoplasms are lacking. Here, we conducted a systematic review of the literature for a descriptive analysis of temozolomide-associated myelodysplasias and leukemias to guide treatment planning. A database search of PubMed and Embase was conducted to identify case reports and/or case series reporting secondary myelodysplasias or leukemias in the setting of temozolomide therapy. Key data items extracted from the studies were the temozolomide dose and duration, latency to hematological disorder, type of secondary malignancy and cytogenetics. Reported cases were summarized graphically. A total of 16 studies with 27 patient cases of therapy-related hematologic neoplasms were identified, all of which were case reports or case series. The median treatment duration and cumulative dose were 19 months and 18,000 mg/m² , respectively. Most patients (21/27) were diagnosed on, or after, 12 months, while only one patient was diagnosed before 6 months of treatment. Most of the patients were diagnosed, while still on treatment with temozolomide. Graphically, cases clustered around a cumulative dose of 10,000 to 30,000 mg/m² and a latency period of 10 to 40 months which translates to an approximate treatment duration of 12.5 to 37.5 months. Taken together, most reported treatment-related hematological neoplasms appear to develop on or beyond the 12-month mark, while patients are still on treatment with temozolomide. For patients with neuroendocrine neoplasms, where sequencing of multiple therapies is important, we suggest an approach to optimizing treatment duration by establishing disease response at 6 months before continuing further treatment and restricting treatment to or establishing closer vigilance beyond 12 months.

Acute lymphoblastic leukemia following temozolomide treatment in a patient with glioblastoma: A case report and review of the literature

Temozolomide (TMZ) is a second-generation oral alkylating agent that functions against a number of central nervous system neoplasms, and is generally used to treat high-grade gliomas, including anaplastic astrocytoma and glioblastoma multiforme. Therapy-related secondary myelodysplastic syndrome and acute myeloid leukemia have been reported in patients following prolonged exposure to TMZ. However, TMZ-related acute lymphoblastic leukemia (ALL) is extremely rare. The present study describes the case of an 11-year-old boy with a 3-day history of generalized tonic-clonic seizures and a contrast-enhanced lesion in the left temporooccipital region with focal cystic degeneration, as detected by magnetic resonance imaging. The patient underwent craniotomy and gross-total resection andpathological analysis confirmed the diagnosis of giant cell glioblastoma. Postoperatively, the patient received TMZ-based concurrent chemoradiation during radiotherapy, and developed B-cell ALL 6 months following TMZ treatment. A thorough literature search identified only six published cases of TMZ-related ALL. The chemotherapeutic efficacy of TMZ has been identified, however, its leukemogenic potential should be emphasized among practitioners and patients. Further studies are required to determine the specific pathogenic mechanism of TMZ-related ALL. Close hematological monitoring of patients following TMZ treatment is vital and a high index of suspicion is necessary.

Haematological malignancies following temozolomide treatment for paediatric high-grade glioma

BACKGROUND

Temozolomide (TMZ) is widely used in high-grade glioma (HGG). There is a major concern of treatment-induced secondary haematological malignancies (SHMs). Due to the poor overall survival of HGG patients, the true incidence is yet elusive. Thus, the aim of this study was to determine the risk of SHMs following TMZ in paediatric HGG.

METHODS

We analysed 487 patients from the HIT-HGG database of the German-speaking Society of Pediatric Oncology and Hematology with follow up beyond 1 year.

RESULTS

The incidence of SHM was 7.7 ± 3.2% at 10 years. No SHM occurred in 194 patients after first-line TMZ therapy, but four out of 131 patients treated with TMZ for relapse following first-line multiagent chemotherapy experienced SHM (20% at 10 years; p = 0.041). SHMs occurred in two out of 162 patients who underwent multiagent chemotherapy without TMZ (4.1% at 10 years). Gender, patient age and acute haematological toxicity during treatment did not affect the incidence of SHMs.

CONCLUSION

Data of our cohort do not indicate an increased risk of SHM following TMZ treatment when compared to previous chemotherapy regimen. However, if TMZ is administered as a second-line treatment following conventional chemotherapy regimen, the risk might be disproportionately increasing.

A Case of Therapy-Related Acute Myeloid Leukemia Associated with Adjuvant Temozolomide Chemotherapy for Anaplastic Astrocytoma

BACKGROUND

Temozolomide (TMZ) is now standard adjuvant therapy in combination with radiotherapy for patients with newly diagnosed malignant glioma. Treatment-related myelodysplastic syndrome and acute treatment-related leukemia (t-AML) associated with TMZ chemotherapy for patients with glioma is quite a rare complication.

CASE DESCRIPTION

A 43-year-old man with an anaplastic astrocytoma received radiation therapy synchronized with ranimustine and adjuvant TMZ chemotherapy for 15 cycles. Close follow-up magnetic resonance imaging of the head during TMZ chemotherapy showed no evidence of tumor progression. One year after the completion of TMZ chemotherapy, a bone-marrow aspiration was performed because the patient's white blood cell count decreased. He was diagnosed with t-AML based on the bone marrow examination, and then he was referred to the cancer center for the treatment of t-AML.

CONCLUSIONS

In this case study, we continued adjuvant TMZ therapy beyond the recommended 6 cycles. Currently, there is no consensus as to how long the adjuvant TMZ therapy should be continued for the treatment of residual tumor showing no apparent interval change. A new decision-making tool to assess the clinical benefits against the side effects for long-term adjuvant TMZ therapy is needed.

The survival significance of a measurable enhancing lesion after completing standard treatment for newly diagnosed glioblastoma

The goal of this study was to analyze the survival outcome according to the treatment response after completing standard treatment protocol for newly diagnosed glioblastoma (GBM) and to suggest a patient who should be considered for further treatment. After approving by our Institutional Review Board, 57 patients (38 male, 19 female; median age, 52years; age range, 16-81years) with newly diagnosed GBM who completed standard treatment protocol were examined retrospectively. According to the treatment response using the RANO criteria, there were 20 patients with complete response (CR), five patients with partial response (PR), 13 patients with stable disease (SD) and 19 patients with progressive disease (PD) after the completion of standard treatment. Patients (PR+SD+PD) with a measurable enhancing lesion were categorized the MEL group (n=37). We analyzed the difference of survival outcome between CR group and MEL group. The median progression-free survival (PFS) in the CR group was significantly better than that of the MEL group (18.0months vs. 3.0months, p=0.004). The median overall survival (OS) was also significantly longer in the CR group (25.0months vs. 15.0months, p=0.005). However, there was no significant difference in the survival outcome of the CR group compared with that of the subset of MEL group patients who showed PR or SD. Poor survival outcome was found only in MEL group patients who exhibited progression. Patients with a measurable enhancing lesion showing progression after completion of standard treatment protocol are appropriate candidates for further treatment.

An early and rare second malignancy in a treated glioblastoma multiforme: is it radiation or temozolomide?

Glioblastoma Multiforme (GBM) is a high-grade brain tumour with the most dismal prognosis. There are very few reports on second malignancies occurring in GBM patients, as the survival has been short. Second malignancies have been reported after treatment of malignancies with radiation therapy and chemotherapy especially after 5 to 10 y of treatment. Here in, we present a very unique case where a patient succumbed to sinonasal carcinoma occurring one and half years after treatment of GBM. A 17-year-old boy was diagnosed to have GBM and underwent surgery followed by chemoradiation and adjuvant chemotherapy with Temozolamide. He presented with undifferentiated sinonasal carcinoma, in the sinonasal region outside the radiation field within two years of treatment. Here we discuss the histology and possible chances of it being a second malignancy.

Secondary hematological malignancies associated with temozolomide in patients with glioma

BACKGROUND

The alkylating agent temozolomide (TMZ) is widely used for the treatment of gliomas. Although reports of treatment-related myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and acute lymphoblastic leukemia (ALL) associated with TMZ are accumulating, it remains unclear whether TMZ has the same leukemogenic potential as other alkylating agents.

METHODS

We performed a single-institution retrospective analysis using a database of 359 glioma patients given nimustine (ACNU)-based therapy, TMZ-based therapy, or combination therapy, who were followed up for a minimum of 2 months, between January 1990 and December 2009, at the National Cancer Center Hospital in Japan.

RESULTS

Of the 359 patients, 225 received ACNU alone or ACNU plus other chemotherapeutic drugs (ACNU-based group; median follow-up period, 31.4 mo), 63 patients received ACNU-based therapy followed by TMZ therapy (ACNU-TMZ group; median follow-up period, 19.1 mo), and 71 patients received TMZ alone or TMZ plus other chemotherapeutic drugs (TMZ-based group; median follow-up period, 16.9 mo). Three patients in the ACNU-based group developed MDS/AML (incidence rate: 2.9 cases per 1000 person-years), 2 patients in the ACNU-TMZ group developed MDS/AML (13.0 cases per 1000 person-years), and 1 patient in the TMZ-based group developed ALL (9.9 cases per 1000 person-years).

CONCLUSIONS

Despite the limitations of this study, published reports and our results suggest that TMZ induces secondary hematological malignancies, particularly ALL, and might shorten the latency period when used in combination with other chemotherapeutic agents.

Temozolomide-related hematologic toxicity

Temozolomide (TMZ) is an oral alkylating agent used for the treatment of recurrent or newly diagnosed malignant gliomas with significant survival benefit. TMZ is generally well tolerated and safe. The most common side effects are mild to moderate, and are represented by fatigue, nausea, vomiting, thrombocytopenia, and neutropenia. However severe hematologic adverse events (HAEs), including myelodysplastic syndrome and aplastic anemia, have also been reported. In this review we present an overview of the available literature of HAEs after exposure to TMZ.

Initial testing (stage 1) of temozolomide by the pediatric preclinical testing program

BACKGROUND

The DNA methylating agent temozolomide was developed primarily for treatment of glioblastoma. However, preclinical data have suggested a broader application for treatment of childhood cancer. Temozolomide was tested against the PPTP solid tumor and ALL models.

PROCEDURES

Temozolomide was tested against the PPTP in vitro panel at concentrations ranging from 0.1 to 1,000 µM and was tested against the PPTP in vivo panels at doses from 22 to 100 mg/kg administered orally daily for 5 days, repeated at day 21.

RESULTS

In vitro temozolomide showed cytotoxicity with a median relative IC50 (rIC50 ) value of 380 µM against the PPTP cell lines (range 1 to > 1,000 µM). The three lines with rIC50 values lesser than 10 µM had low MGMT expression compared to the remaining cell lines. In vivo temozolomide demonstrated significant toxicity at 100 mg/kg, but induced tumor regressions in 15 of 23 evaluable solid tumor models (13 maintained CR [MCR], 2 CR) and 5 of 8 ALL models (3 MCR, 2 CR). There was a steep dose response curve, with lower activity at 66 mg/kg temozolomide and with tumor regressions at 22 and 44 mg/kg restricted to models with low MGMT expression.

CONCLUSIONS

Temozolomide demonstrated high level antitumor activity against both solid tumor and leukemia models, but also elicited significant toxicity at the highest dose level. Lowering the dose of TMZ to more closely match clinical exposures markedly reduced the antitumor activity for many xenograft lines with responsiveness at lower doses closely related to low MGMT expression.

Temozolomide-related idiosyncratic and other uncommon toxicities: a systematic review

Temozolomide (TMZ)-related idiosyncratic and other uncommon toxicities have been reported. To better characterize these toxicities and to identify any associated risk factors, we performed a systematic review. We searched the PubMed database, limited to the English language, published between 1999 and December 2011. We selected only those articles in which TMZ was temporally related and was the sole or main contributing chemotherapeutic drug to idiosyncratic drug reactions (IDRs) and other uncommon toxicities. Hematological IDRs are biopsy-proven aplastic anemia or grade V toxicity or grade IV toxicity with slow and incomplete hematological recovery. Seventy-three cases were identified, including 21 hematological IDRs, 31 nonhematological IDRs and uncommon infections, and 21 second primary cancers. With a caveat of publication and reporting bias, the following observations could be made. The hematological IDRs predominantly occurred in female patients (exact binomial two-tailed, P=0.0041) and most patients were receiving TMZ concomitantly with radiotherapy for glioma. The median duration of exposure to TMZ was 30 days and the median cumulative TMZ exposure was 2250 mg/m (range, 500-6900 mg/m). The sex predilection was not evident in nonhematological IDRs and other uncommon toxicities. TMZ-induced pneumonitis and cholestatic hepatitis are emerging as a nonhematological hypersensitive reaction and IDR, respectively. For TMZ-related myelodysplasia or leukemia, the cumulative dose of TMZ ranged from 1400 to 30 000 mg/m. The cumulative dose of TMZ was lower and latency was shorter with a previous exposure to other leukemogenic drugs, suggesting that TMZ may have augmented the leukemogenic potential of other drugs. Early appearance of profound myelosuppression during the course of TMZ and concurrent radiotherapy could be a hematological IDR, which warrants prompt investigations to exclude aplastic anemia. Myelodysplasia or leukemia developed after a median TMZ exposure of 15 g/m.

Non-hodgkin lymphoma after treatment with extended dosing temozolomide and radiotherapy for a glioblastoma: a case report

Temozolomide (TMZ) is an alkylating agent, used for the treatment of high-grade gliomas. This case report describes the development of a non-Hodgkin lymphoma in a patient treated with extended-dose temozolomide and radiotherapy. In addition to the possible mutagenic effect of temozolomide – as described for all alkylating agents – there might have been an immunosuppressive effect of TMZ. The pathological appearance of the lymphoma as well as the presence of a grade 3 lymphopenia early in treatment supports this hypothesis. As the use of TMZ increases, the awareness that TMZ may induce secondary malignancies should increase as well.

Temozolomide in the management of dopamine agonist-resistant prolactinomas

BACKGROUND

The majority of prolactinomas respond to dopamine agonist therapy, but a proportion are resistant, requiring other treatments including surgery and/or radiotherapy. Temozolomide is an oral chemotherapy agent, which has been used as a salvage therapy to treat aggressive pituitary adenomas and carcinomas, including prolactinomas, unresponsive to all conventional treatment.

CASE SERIES

We report three patients where temozolomide was used in the treatment of refractory prolactinomas. Case 1 describes a patient with a highly invasive prolactinoma, resistant to all conventional therapy, which responded dramatically to temozolomide used as a salvage treatment. In case 2, temozolomide was used after incomplete surgical resection to relieve chiasmal compression and avoid chiasm exposure to radiotherapy. In case 3, temozolomide enabled radiotherapy to be deferred in a 16-year old with a resistant prolactinoma. In all three cases, the tumours were negative by immunostaining for methylguanine methyltransferase (MGMT).

LITERATURE REVIEW AND DISCUSSION

A review of the published literature reveals 51 reported cases of temozolomide treatment for pituitary tumours, including 20 prolactinomas. Fifteen of the 20 prolactinomas showed a good response to temozolomide. Our analysis demonstrates a strong association between MGMT-negative staining and a good response to temozolomide (OR 9.35, P = 0.0030). Current clinical practice is to use temozolomide as a salvage therapy after all conventional modalities of treatment have failed. We suggest that, in selected cases, consideration should be given to using temozolomide earlier in the treatment algorithm.