Case report: a patient with primary CNS lymphoma treated with temozolomide to complete response

Management of primary central nervous system lymphoma

A rare tumor, primary central nervous system lymphoma can affect immunocompetent and immunocompromised patients. While sensitive to radiotherapy or chemotherapy crossing the blood-brain barrier, it often recurs. Modern treatment consists of high-dose methotrexate-based induction chemotherapy, often followed by consolidation with either radiotherapy or further chemotherapy. Neurotoxicity is however a concern with radiotherapy, especially for patients older than 60 years. The benefit of the addition of rituximab to chemotherapy is unclear. Targeted therapies and immunotherapy have been effective in some patients and are tested on a larger scale. Survival has improved in the last decade, but remains poor in older patients.

O6-methylguanine-DNA methyltransferase (MGMT) immunohistochemistry as a predictor of resistance to temozolomide in primary CNS lymphoma

Temozolomide, an alkylating agent, has shown promise in treating primary central nervous system lymphoma (PCNSL). The enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) repairs alkylating damage, such as that induced by temozolomide. We hypothesized that MGMT immunohistochemistry would predict resistance to temozolomide in PCNSL. A retrospective study of newly-diagnosed and recurrent PCNSL patients treated at our institution was conducted to study the predictive value of MGMT immunohistochemistry for response to temozolomide. 20 patients who were treated with temozolomide as a single agent were identified during the study time period. 6/20 patients demonstrated a response, corresponding to an objective response rate of 30 % (95 % CI 8-52). Five patients with low MGMT level (<30 %) showed a response to temozolomide. Only one of 10 patients (10 %) with high MGMT level (≥30 %) exhibited a response to temozolomide. Small sample numbers precluded formal statistical comparisons. Two patients with complete response remain alive without progressive disease 6.7 and 7.2 years after temozolomide initiation. Immunohistochemistry can be performed on small biopsies to selectively assess MGMT status in tumor versus surrounding inflammation. MGMT analysis by immunohistochemistry may predict response to temozolomide in PCNSL and should be prospectively investigated.

Temozolomide and methotrexate for primary central nervous system lymphoma in the elderly

BACKGROUND

Treatment for primary CNS lymphoma (PCNSL) in the elderly is associated with lower response rates and higher risks of acute and late delayed toxicity as compared to younger patients. Temozolomide has emerged as a new alternative treatment for PCNSL and constitutes an attractive option for the elderly because of its favorable toxicity profile. In this study we report outcomes of a consecutive series of PCNSL elderly patients initially treated with an innovative regimen combining methotrexate and temozolomide without radiotherapy or intra-thecal chemotherapy.

METHODS

Histologically confirmed newly-diagnosed PCNSL patients older than 60 years were included. An induction chemotherapy was initially given (methotrexate 3 g /m(2) on days 1, 10, and 20, and temozolomide 100 mg/m(2) on days 1-5). Patients achieving a partial or complete response proceeded to a maintenance phase (up to 5 monthly cycles of methotrexate 3 g/m(2) on day 1, and temozolomide 100 mg/m(2 )days 1-5). Non-responders were treated on an individual basis.

RESULTS

Among the 23 included patients, a complete response was observed in 55%, and disease progressed in the other 45%. Median event-free survival was 8 months, and median overall survival was 35 months. Grades 3 or 4 toxicities included nephrotoxicity in three patients, and hematotoxicity in five; no neurotoxicity has been observed to date. One patient died while on treatment from complications of intestinal obstruction.

CONCLUSION

Our efficacy results are comparable to other reported regimens, with the advantages of a favorable toxicity profile, and absence of intra-thecal chemotherapy. Prospective, controlled studies are warranted to confirm such results.

Complete response to temozolomide treatment in an elderly patient with recurrent primary central nervous system lymphoma--case report

An 80-year-old woman presented with primary central nervous system (CNS) lymphoma manifesting as progressive disorientation and loss of activity. She received three cycles of high-dose methotrexate. The tumor shrank after two cycles and her mental status improved, but she suffered tumor recurrence. The second-line treatment consisted of four cycles of rituximab but the tumor enlarged. She was then treated with three cycles of temozolomide. Magnetic resonance imaging revealed no evidence of disease. Her mental status and performance status improved, and she suffered no toxicity. She is able to pursue her daily life without recurrence after 16 cycles of temozolomide. Temozolomide may be effective against relapsed primary CNS lymphoma without causing neurotoxicity in the elderly.

Primary Lymphoma of the Nervous System

This review article provides guidelines for the diagnosis, staging, and management of primary nervous system lymphoma based on the results of clinical trials conducted during the last decade. Recent progress in our understanding of the pathogenesis of primary nervous system lymphoma is summarized, and implications of these findings for the development of diagnostic tools and new therapeutic strategies are outlined. We performed a search of the PubMed database (National Center for Biotechnology Information) for articles on primary nervous system lymphoma published between 1970 and May 2005. Primary nervous system lymphoma affects the brain, eye, and meninges as well as cranial, spinal, and peripheral nerves. Although important lessons have been learned from the pathogenesis of extraneural non-Hodgkin's lymphoma, the unique organotropism of primary nervous system lymphoma remains poorly understood. Diagnosis is facilitated by modern imaging techniques and molecular markers. Clinically recognizable "precursors" may exist but frequently elude specific diagnosis. Insight into the peculiar pharmacokinetics of chemotherapy aimed at tumors within the nervous system has led to the development of methotrexate-based regimens that can achieve prolonged progression-free survival without the use of radiation. Long-term survival and, in selected cases, even a cure are possible in primary nervous system lymphoma. Treatment should be provided in specialized multidisciplinary centers. In spite of remarkable progress through methotrexate-based chemotherapy, the majority of patients experience relapse within a few years. Better diagnostic tools are required for earlier diagnosis and monitoring of treatment response. A deeper understanding of the pathogenesis of primary nervous system lymphoma may reveal new therapeutic targets.

Immunochemotherapy with rituximab and temozolomide for central nervous system lymphomas

BACKGROUND

Methotrexate-based and alkylator-based chemotherapy regimens are associated with renal and bone marrow toxicities, which limit their use in patients with central nervous system (CNS) lymphomas. The authors report their experience with an immunochemotherapy regimen consisting of rituximab and temozolomide in patients with primary or metastatic CNS lymphoma.

METHODS

Seven patients who had received rituximab and temozolomide were identified from the database of the brain tumor clinic at the authors' institution: three patients had developed recurrent primary CNS lymphoma (PCNSL), one patient had newly diagnosed PCNSL but had poor renal function, and three other patients with systemic non-Hodgkin lymphoma developed recurrent lymphoma in the brain only. Patients were scheduled to receive 4 cycles of induction rituximab on Day 1 and temozolomide on Days 1-5 of a 28-day cycle. Thereafter, their treatment included a total of up to 8 maintenance cycles of temozolomide alone on Days 1-5 of a 28-day cycle. A gadolinium-enhanced magnetic resonance image of the head was obtained after every two cycles of treatment.

RESULTS

All patients received rituximab without toxicity. Of the 4 patients who received induction temozolomide at doses > 150 mg/m(2) daily on Days 1-5, 2 experienced Grade 2 leukopenia and thrombocytopenia. Five patients achieved a radiographic complete response, and two patients had partial responses after induction treatment. The median response duration was 6 months (range 3-12+ months), and the median survival was 8 months (range 3+-12+ months).

CONCLUSIONS

Although median survival was short, immunochemotherapy with rituximab and temozolomide was well tolerated and exhibited efficacy in this elderly and heavily pretreated cohort. The data obtained in the current study suggest that the optimal induction dose combination consists of rituximab 375 mg/m(2) on Day 1 and temozolomide 150 mg/m(2) daily on Days 1-5.

Salvage chemotherapy with temozolomide in primary CNS lymphomas: preliminary results of a phase II trial

Temozolomide is a well-tolerated alkylating agent, that is able to permeate the blood-brain barrier (BBB), and has additive cytotoxicity when given with radiotherapy (RT). A phase II trial assessing temozolomide 150 mg/m(2)/day, for 5 days every 28 days in primary central nervous system (CNS) lymphoma (PCNSL) patients with negative human immunodeficiency virus (HIV) serology, Eastern Cooperative Oncology Group (ECOG) performance status (PS)<4, previously treated with high-dose methotrexate-containing (HD-MTX) chemotherapy and/or RT was started. Twenty-three patients were enrolled. Median age was 60 years. Five complete remissions (median duration 6+ months; range 2-36 months), one partial response, four stable disease (median duration 7.2 months, range 2-16.5 months), and 13 progressions were observed. No major toxicities were observed, apart grade 3 vomiting in a single cycle. Main grade 1-2 toxicities were: 15% nausea, 6% vomiting, 9% fatigue and 9% neurological symptoms. This is the first prospective trial assessing single-agent activity in PCNSL at failure. Although some patients had a poor PS and had been heavily pre-treated, temozolomide yielded 26% objective responses and was well tolerated without any major toxicity.

Treatment of primary central nervous system lymphoma in the elderly

Although the incidence of primary central nervous system lymphoma has recently declined among people with acquired immunodeficiency syndrome, the incidence of primary central nervous system lymphoma remains high among the immunocompetent population >/=60 years of age. Elderly patients represent an important subgroup that accounts for approximately half of primary central nervous system lymphoma cases. Radiotherapy (RT) alone has produced disappointing results in the elderly. Improved clinical outcomes have been achieved with high-dose methotrexate-based chemotherapy regimens in combination with whole-brain RT. Unfortunately, combination therapy exposes elderly patients to a high risk of severe delayed neurotoxicity in up to 80%. Chemotherapy alone may be the best approach for treating elderly patients and appears to be more effective than RT, while considerably reducing the risk of neurotoxicity. Clinical studies are needed to define the optimal chemotherapy regimen for the elderly in an effort to delay or completely avoid the need for RT.