Radiotherapy plus concurrent and adjuvant procarbazine, lomustine, and vincristine chemotherapy for patients with malignant glioma

We analyzed the clinical efficacy and toxicity of concurrent therapy as a first line modality for malignant glioma patients. From 1998 to 2004, 39 patients, 22 with glioblastoma (GM), nine with anaplastic astrocytoma (AA), 7 with anaplastic oligodendroglioma (AO) and 1 with anaplastic oligodendro-astrocytoma (AOA) were enrolled in this study. The median age was 46.2 years (range 8-67). Both external involved field radiotherapy and chemotherapy, composed of CCNU (75-110 mg/m(2)), procarbazine (60 mg/m(2)) and vincristine (1.4 mg/m(2)), were started simultaneously two weeks after surgery. The median progression-free survival time for the GM, AA, and AO patients was 6, 26, and 31 months, respectively. The median survival of the patients with GM and AA was 27 and 41 months. The two-year survival rate of the GM and AA patients was 50.4 and 66.7%, respectively. Grade III/IV hematological toxicity was reduced from 25.6 to 13% after reduction of the dose of CCNU (75 mg/m(2)). Radiation necrosis was confirmed by pathologic examination in four patients (10.3%). The median interval from the completion of radiotherapy to the diagnosis of necrosis was 19 weeks. Modified concurrent chemoradiotherapy may be a feasible option for treating malignant glioma with acceptable toxicity.     

Phase II trial of procarbazine, vincristine and lomustine (POC) chemotherapy in metastatic cutaneous malignant melanoma

40 patients with symptomatic metastatic melanoma were treated with procarbazine, vincristine and lomustine (POC). 4 patients had received chemotherapy previously. Responses were seen in 8 patients (20%), 4 of whom had a complete remission. All responding patients had some rumour shrinkage after one cycle. The median duration of response was 27 weeks, with 2 patients remaining in complete remission at 6 and 6.5 years. The median survival for the whole group was 22 weeks, whilst that of the responding patients was 35 weeks. Using conventional anti-emetics, the principal toxicities were nausea and vomiting, severe in 15% of cycles. Other nonhaematological toxicity was uncommon. Neutropenia (WHO grade 3 or 4) occurred in 11% of cycles and thrombocytopenia in 8%. The response rate of metastatic melanoma to POC chemotherapy was similar to other cytotoxic regimens though toxicity, other than nausea and vomiting, was minimal. The rapid response allows patients with unresponsive disease to be identified early, avoiding continuing toxicity.     

Efficacy and feasibility of standard procarbazine, lomustine, and vincristine chemotherapy in anaplastic oligodendroglioma and oligoastrocytoma recurrent after radiotherapy. A Phase II study

BACKGROUND: To the authors' knowledge, there is a scarcity of accurate data regarding the feasibility of standard chemotherapy with procarbazine, lomustine, and vincristine (PCV) in a homogeneous series of patients with primary anaplastic oligodendroglioma (AO) and oligoastrocytoma (AOA) that was recurrent after surgery and standard radiotherapy. The aim of the current study was to evaluate the overall response rate, toxicity, and time to progression (TTP) with the use of standard PCV in this setting. METHODS: Between November 1994 and September 2000, 37 patients were enrolled in the current study. Of these, 23 had AO (62%) and 14 had AOA (38%). All patients received standard PCV comprised of lomustine (110 mg/m2) on Day 1, procarbazine (60 mg/m2) on Days 8-21, and vincristine (1.4 mg/m2, maximum total 2 mg) on Days 8 and 29. Cycles were repeated every 6 weeks. RESULTS: There were 11 complete responses (CR; 29.7%) and 11 partial responses (PR; 29.7%) reported and 8 patients had stable disease (SD; 21.6%). The response rate was higher in patients with AO compared with patients with AOA (77.2% vs. 22.7%; P = 0. 02). The median TTP, which was 12.3 months overall, was 30.3 months in patients who achieved a CR, 19.1 months in patients who achieved a PR, and 6.1 months in patients with SD. The median TTP was 18.6 months in AO patients and 6.14 in AOA patients. There were no cases of severe toxicity reported although in 16 patients (43%) who were free of disease progression, PCV was discontinued because of toxicity or inadequate recovery after 2 weeks of delay. CONCLUSIONS: PCV chemotherapy was reported to achieved a high response rate and TTP but incurred a high risk of persistent toxicity.     

Mechlorethamine, vincristine, and procarbazine chemotherapy for recurrent high-grade glioma in adults: a phase II study

We undertook a phase II study of combination chemotherapy with mechlorethamine (nitrogen mustard) 6 mg/m2 intravenously day 1 and day 8, vincristine 2 mg intravenously day 1 and day 8, and procarbazine 100 mg/m2 orally days 1 through 14 (MOP) in adults with recurrent high-grade glioma. There were 31 patients entered and 27 patients assessable for response. The median age was 49 years old. All patients had prior maximal radiotherapy, and eight had previous chemotherapy. Responses were determined based on clinical and computed tomographic (CT) scan/magnetic resonance imaging (MRI) criteria. The response rate (partial response [PR] plus objective qualitative response [OQR] plus complete response [CR]) was 52% with one CR. The response rate was higher in patients with anaplastic astrocytoma as compared with glioblastoma multiforme (P less than .05). The median duration of response was 42 weeks. Median survival for all assessable patients was 30 weeks, and for responders, it was 60 weeks. Response was correlated with ability to decrease dexamethasone doses and improved performance status. Toxicity was mainly hematologic with leukopenia being common. There was one treatment-related death from listeria meningitis, and two patients developed Pneumocystis carinii pneumonia. There were three episodes of neutropenic fever. We conclude that MOP is active and merits further investigation in adult high-grade glioma.     

Clinical feasibility of modified procarbazine and lomustine chemotherapy without vincristine as a salvage treatment for recurrent adult glioma

Procarbazine, lomustine and vincristine (PCV) chemotherapy is considered a salvage option for adult glioma; however, its significant toxicities frequently lead to dose reduction or discontinuation in patients with recurrent glioma. The current study evaluated the safety and efficacy of modified procarbazine and lomustine (PC) chemotherapy that omits vincristine and reduces the lomustine dose compared with those of conventional PCV chemotherapy. Using electronic medical records, all patients with adult recurrent glioma who received PC or PCV chemotherapy between 2009 and 2020 at Seoul St. Mary''s Hospital or St. Vincent''s Hospital were examined retrospectively. A total of 59 patients met the eligibility criteria. Among them, 15 patients received modified PC chemotherapy (PC group) and 44 patients received PCV chemotherapy (PCV group). The PC group presented a significantly lower hematology toxicity (anemia, 6.7 vs. 45.5%, P=0.02; thrombocytopenia 20.0 vs. 70.4%, P<0.001). Additionally, the clinical impacts of PC chemotherapy, including delay of a cycle, dose reduction, discontinuation of drug(s) or total cessation of chemotherapy, were significantly less frequent compared with the PCV group (26.7 vs. 68.2%, P=0.012). The overall survival of the PC group was also significantly longer than that of PCV group (396 vs. 232 days, P=0.042), while there was no significant difference in progression-free survival between the two groups (284.5 vs. 131 days, P=0.077). The results suggested that modified PC chemotherapy may be an alternative chemotherapeutic regimen with tolerable toxicity and without loss of clinical efficacy in patients with recurrent adult glioma. Further prospective and larger studies are required to validate our findings.     

Successful treatment of low-grade oligodendroglial tumors with a chemotherapy regimen of procarbazine, lomustine, and vincristine

BACKGROUND: Anaplastic oligodendroglioma (OD) tumors, especially those with the combined loss of the short arm of chromosome 1 (1p) and the long arm of chromosome 19 (19q), are sensitive to chemotherapy. Only limited data are available on the role of chemotherapy in low-grade OD. The authors retrospectively studied the outcome of the procarbazine, lomustine, and vincristine (PCV) chemotherapy regimen in a group of 16 patients with newly diagnosed OD and 5 patients with recurrent low-grade OD. METHODS: Two groups of patients were studied: newly diagnosed patients with large OD and mixed oligoastrocytomas (OA) and patients with recurrent OD and OA after radiotherapy who still showed nonenhancing tumors. Treatment consisted of standard PCV chemotherapy. In the newly diagnosed and responding patients, radiotherapy was withheld until the time of disease recurrence. Responses were assessed by T2-weighted magnetic resonance image (MRI) scans. Loss of chromosome 1p and 19q was assessed using fluorescent in situ hybridization with locus-specific probes. RESULTS: Three of five patients with recurrent tumors responded. Thirteen of the 16 newly diagnosed patients showed evidence of response. The median time to disease progression in this group was >24 months. Only one of these patients experienced disease progression while receiving chemotherapy. Several patients showed a signficant clinical improvement despite only a modest improvement of the tumor on the MRI scans. Even patients without loss of 1p or 19q showed satisfactory responses. No TP53 mutations were found. CONCLUSIONS: Newly diagnosed patients with OD tumors, with or without loss of 1p/19q, responded to PCV chemotherapy. Up-front chemotherapy may be indicated especially for patients with large tumors. MRI scans were of limited value for the assessment of response. A Phase III trial should be initiated to compare radiotherapy with chemotherapy.     

Hypersensitivity reactions to procarbazine with mechlorethamine, vincristine, and procarbazine chemotherapy in the treatment of glioma.

The authors report the clinical features of hypersensitivity reactions believed to result from procarbazine in eight patients treated with mechlorethamine, vincristine, and procarbazine (MOP) for high-grade glioma. There was one instance of hypersensitivity in 7 patients treated for recurrent disease and seven instances in 16 patients treated with an adjuvant protocol using MOP directly after surgery. Maculopapular rash was seen in seven of eight, fever was seen in four of eight, and reversible abnormal liver function test results were seen in three of four patients. Pulmonary toxic effects were seen in five of eight patients and consisted of isolated interstitial pneumonitis in one, fever and infiltrate after rechallenge with procarbazine after previous rash in two, and cough accompanying rash in two. The toxic effects were mild to moderate in six patients but severe to life threatening in the two who were rechallenged after development of rash. The observed incidence of rash during adjuvant therapy was higher than that previously found by the authors for recurrent disease, and it appears to be higher than has been reported in Hodgkin's disease, lymphoma, and other solid tumors. The findings by the authors suggest that a high index of suspicion be kept for hypersensitivity reactions to procarbazine when treating primary brain tumors and that, contrary to the experience in other settings, procarbazine be stopped if rash develops.     

A phase II trial of high-dose bromodeoxyuridine with accelerated fractionation radiotherapy followed by procarbazine, lomustine, and vincristine for glioblastoma multiforme.

PURPOSE: To conduct a Phase II study to evaluate the long-term efficacy and safety of high-dose 5'-bromodeoxyuridine (BrdU) and accelerated radiotherapy followed by procarbazine, lomustine (CCNU), and vincristine (PCV) chemotherapy in patients with glioblastoma multiforme. METHODS AND MATERIALS: Between 1994 and 1996, 88 patients were enrolled to receive 1.9 Gy of radiation three times a day for two 5-day cycles separated by 2 weeks; each 5-day cycle was preceded by a continuous 96-hour infusion of BrdU at a dose of 2.1 g/m2/day. After radiotherapy, patients received PCV chemotherapy. RESULTS: Median survival for all 88 patients was 50 weeks. Seventy (79.5 %) received one or more courses of PCV; their median survival was 57 weeks. Covariates predictive of improved survival were gross total versus subtotal resection or biopsy (p = 0.0048) and radiation dose > or = 56 Gy (p = 0.019). While receiving BrdU, 47 patients (53%) suffered grade 3 or 4 thrombocytopenia or leukopenia; 22 patients (25%) suffered grade 3 or 4 dermatologic toxicity. CONCLUSION: Survival was not extended in patients with glioblastoma or gliosarcoma who received BrdU at the dose and administration schedule used in this study. The BrdU dose used in this study resulted in substantial myelosuppressive and dermatologic toxicity.     

Second-line treatment with carboplatin for recurrent or progressive oligodendroglial tumors after PCV (procarbazine, lomustine, and vincristine) chemotherapy: a phase II study

BACKGROUND: The efficacy of second-line chemotherapy for patients with recurrent or progressive oligodendroglial tumors is limited. In the current study, the authors investigated the use of carboplatin as a second-line chemotherapeutic agent against these types of tumors. METHODS: Twenty-three patients with recurrent or progressive oligodendrogliomas or oligoastrocytomas after first-line PCV (procarbazine, lomustine, and vincristine) chemotherapy were enrolled in a single-institution Phase II study of second-line carboplatin chemotherapy. All patients had undergone surgery, and most also had undergone conventional radiotherapy. Carboplatin was administered at a dose of 560 mg/m2 intravenously every 4 weeks. Responses were evaluated according to conventional criteria, based on magnetic resonance imaging (MRI) findings. RESULTS: Three of 23 patients (13%) had partial responses, with neurologic improvement. Twelve patients (52%) had stable disease; in 2 of these 12 patients, a minor response was seen on MRI. Eight patients (35%) had progressive disease. The median time to tumor progression was 3 months for all patients and 9 months for patients who experienced responses to treatment. Progression-free survival rates at 6 and 12 months were 34.8% and 8.7%, respectively. Among the salvage treatment plans followed after carboplatin chemotherapy were supportive care alone, radiotherapy, third-line chemotherapy, and reoperation. The median survival duration from the start of carboplatin administration was 16 months. Myelotoxicity was severe, with Grade 3 or 4 thrombocytopenia in 60% of patients and Grade 3 or 4 neutropenia in 48% of patients. CONCLUSIONS: When administered according to a monthly schedule, carboplatin exhibited modest activity in adult patients with recurrent or progressive oligodendroglioma or oligoastrocytoma who experienced treatment failure after PCV chemotherapy; the current treatment regimen also was associated with severe toxicity. Further improvement of second-line chemotherapy for the patient group examined in the current study is necessary.     

Phase III randomized study of radiotherapy plus procarbazine, lomustine, and vincristine with or without BUdR for treatment of anaplastic astrocytoma: final report of RTOG 9404

PURPOSE: This study was an open-label, randomized Phase III trial in newly diagnosed patients with anaplastic glioma other than glioblastoma multiforme comparing external beam radiotherapy (EBRT) plus adjuvant procarbazine, cyclohexylchloroethylnitrosurea (lomustine), and vincristine (PCV) chemotherapy with or without bromodeoxyuridine (BUdR) given as a 96-h infusion each week of RT. METHODS AND MATERIALS: Only patients 18 years or older with newly diagnosed anaplastic glioma were eligible. A central pathology review was accomplished for most patients, but was not mandated before registration. The study had initially opened as a Northern California Oncology Group trial in 1991, becoming an Intergroup Radiation Therapy Oncology Group (RTOG), Southwestern Oncology Group and the North Central Cancer Treatment Group study in July 1994. A total accrual of 293 patients was planned for the sample size, using survival as the primary end point. The experimental arm (RT/BUdR + PCV) was to be compared with the control arm (RT + PCV) using a one-sided alpha = 0.05, with a power of 85% for detecting an increase in median survival from 160 to 240 weeks, assuming a 3-year follow-up after enrollment completion. RESULTS: Between July 1994 and August 1996, 134 patients were randomized to EBRT + PCV (non-BUdR patients) and 134 to EBRT/BUdR + PCV (BUdR patients). The study was closed before the full-anticipated accrual on the basis of an interim analysis that predicted no survival benefit for the BUdR arm. Of the 268 patients, 41 and 37, respectively, were ineligible or canceled primarily on the basis of the central pathology review findings. Thus, 93 patients and 97 patients were eligible/analyzable in the non-BUdR and BUdR arms, respectively. Patient characteristics were well balanced in both arms, with most <50 years old and in the RTOG recursive partitioning analysis (RPA) Class I category. The minimal potential follow-up was 4.6 years. The median survival for non-BUdR patients was 4.1 years compared with 4.6 years for the BUdR patients (p = 0.61). The 4-year overall survival rate was 51% in both arms. For RPA Class I patients (the best prognostic class), the median survival had not been reached for non-BUdR patients (4-year survival rate 61%) and was 5.6 years for BUdR patients (4-year survival rate 64%; p = 0.91). Each arm was also compared with the RTOG historical database for RPA Class I patients with no statistically significant difference found in overall survival (BUdR vs. historical, p = 0.31 and non-BUdR vs. historical, p = 0.48). Grade 4 toxicity occurred in 15 and 17 patients in the non-BUdR and BUdR arms, respectively, with one treatment-related death in the BUdR group. CONCLUSION: No survival advantage was noted by adding BUdR to EBRT and PCV in this patient population     

Combination of 6-thioguanine, capecitabine, and celecoxib with temozolomide or lomustine for recurrent high-grade glioma

We evaluated the efficacy of temozolomide (TMZ) or lomustine (CCNU) in combination with 6-thioguanine, capecitabine, and celecoxib for the treatment of recurrent high-grade glioma. Forty-three patients with recurrent glioblastoma and 31 patients with recurrent anaplastic glioma (AG) were enrolled in this open-label, non-comparative study. Patients previously treated with TMZ received CCNU while all others received TMZ; all patients received 6-thioguanine, capecitabine, and celecoxib. Endpoints were 12-month progression-free survival (PFS) for patients with AG, 6-month PFS for patients with glioblastoma, duration of PFS, and MRI-based objective response rates. Results from the TMZ and CCNU treatment arms were combined in the final analysis because there was no statistically significant difference between them. Thirty-eight patients with glioblastoma were treated with the lomustine-based regimen, and five received the TMZ-based regimen. For the 43 glioblastoma patients, the objective response rate was 12 and 33% had stable disease; the 6-month PFS was 14% and median overall survival 32 weeks. For the 31 AG patients, the combined objective response rate was 26 and 42% had stable disease; the 12 month PFS was 44%. Treatment was reasonably well tolerated with hematological toxicity common and more frequent with CCNU than TMZ. The combination therapy with 6-thioguanine, capecitabine and celecoxib plus CCNU or TMZ does not appear to be more effective than other alkylating agent schedules for patients with recurrent glioblastoma. The combination, however, is promising for patients with recurrent high-grade AG.     

Second-line chemotherapy with temozolomide in recurrent oligodendroglioma after PCV (procarbazine, lomustine and vincristine) chemotherapy: EORTC Brain Tumor Group phase II study 26972.

BACKGROUND: Oligodendroglial tumors are chemosensitive, with two-thirds of patients responding to PCV combination chemotherapy with procarbazine, lomustine (CCNU) and vincristine. Temozolomide (TMZ), a new alkylating and methylating agent has shown high response rates in recurrent anaplastic astrocytoma. We investigated this drug in recurrent oligodendroglial tumors (OD) and mixed oligoastrocytomas (OA) after prior PCV chemotherapy and radiation therapy. PATIENTS AND METHODS: In a prospective non-randomized multicenter phase II trial patients were treated with TMZ 150 mg/m(2) on days 1-5 in cycles of 28 days for 12 cycles. Eligible patients had a recurrence after prior PCV chemotherapy, with measurable and enhancing disease as shown by magnetic resonance imaging. Pathology and all responses were centrally reviewed. RESULTS: Thirty-two eligible patients were included. In four patients the pathology review did not confirm the presence of an OD or OA. Twelve of 24 patients [50%, 95% confidence interval (CI) 29% to 71%] evaluable for response to first-line PCV chemotherapy had responded to PCV. Temozolomide was in general well tolerated; the most frequent side-effects were hematological. One patient discontinued treatment due to toxicity. In seven of 28 patients (25%, 95% CI 11% to 45%) with histologically confirmed OD an objective response to TMZ was observed. Median time to progression for responding patients was 8.0 months. After 6 and 12 months from the start of treatment, 29% and 11% of patients, respectively, were still free from progression. CONCLUSIONS: TMZ may be regarded as the preferred second-line treatment in OD after failure of PCV chemotherapy. Further studies on TMZ in OD are indicated.     

A randomized study of chemotherapy with procarbazine, vincristine, and lomustine with and without radiation therapy for astrocytoma grades 3 and/or 4

The authors undertook a controlled, prospective, randomized study of 171 patients with supratentorial astrocytoma grades 3 and/or 4 (classified according to Kernohan). All patients were given chemotherapy consisting of procarbazine, vincristine, and lomustine (CCNU) (PVC). Half of the patients received whole-brain irradiation (RT) to a dose of 5800 cGy in the tumor-bearing hemisphere and 5000 cGy in the contralateral hemisphere. After diagnosis of progressive tumor growth, patients received individual treatment. The endpoint of the study was time to progression, but cases were followed until the patients died. Median time to progression (MTP) for the whole randomized population was 21 weeks. Median survival time (MST) was 53 weeks; 18% of patients survived for 2 years or longer. Survival analysis showed that patients less than 50 years of age treated with PVC plus RT had significantly longer MTP (81 weeks) and MST (124 weeks) than all other patients. For patients less than 50 years of age treated with PVC alone, MTP was 21 weeks and MST was 66 weeks. For patients more than 50 years of age treated with PVC plus RT, MTP was 23 weeks and MST was 51 weeks; in the PVC group, MTP was 17 weeks and MST was 39 weeks. Age, Karnofsky index, areas of Grade 2, and absence of extensive necrosis in the tumor were significant prognostic factors in the univariate analyses. Patients less than 50 years of age treated with PVC plus RT had significantly longer survival (P = 0.037) when correcting for these factors in a multi-variate analysis.     

Neurotoxicity of combination chemotherapy with procarbazine,CCNU and vincristine (PCV) for recurrent glioma

In cerebral glioma combination chemotherapy with procabazine, CCNU and vincristine (PCV) is used as adjuvant therapy in cases of recurrence. Standard PCV is usually well tolerated, but intensive PCV (CCNU 130 mg/m² on day 1, procarbazine 75 mg/m² on day 8–21, vincristine 1.4 mg/m² on day 8 and 29; 6 courses every 6 weeks) is less well tolerated. We observed central neurotoxic side effects (focal neurological deficit, cognitive disturbances, slowing of EEG background activity, atrophy on cerebral MR) in combination with hematological and hepatic toxicity in four of 26 PCV treated patients with recurrent glioma. Prolonged myelosuppression and/or ongoing (partial reversible in two patients) neurological deficit still influence daily life in three of four patients months after discontinuation of chemotherapy. Despite the fact that all four patients used anticonvulsants and have been treated with radiotherapy in the past, we have the strong impression that central neurotoxic side effects are related to intensive PCV therapy. We advocate to use the standard PCV regimen in patients with recurrent glioma, because of this potential toxicity and the lack of evidence that intensive PCV leads to better tumor control than standard PCV in cerebral glioma.     

Phase II study of dibromodulcitol and BCNU in metastatic malignant melanoma

Dibromodulcitol (DBD) and BCNU were administered to 20 patients with metastatic malignant melanoma who had not received prior chemotherapy. One complete and three partial responses were noted; duration of response was short. Dose limiting toxicity was thrombocytopenia. DBD and BCNU do not appear to improve response over single agent therapy for disseminated melanoma.     

Chemotherapy of nonirradiated malignant gliomas. Phase II: study of the combination of methyl-CCNU, vincristine, and procarbazine.

Twenty-eight adult patients with nonirradiated malignant gliomas of the brain were administered a combination of methyl-CCNU (130 mg/m2, p.o., day 1), vincristine (2 mg/m2, i.v., day 1) and procarbazine (100 mg/m2, p.o., days 2 to 15) (MVP), scheduled to be given at successive 6 week intervals. Nineteen (67.9%) were not responsive to MVP and 9 (32.1%) were. Of 16 who had previous partial resection of their tumors, 8 (50%) responded to MVP and 8 (50%) did not. Of 12 who had previous biopsy, only 1 (8.3%) responded. Overall 1-year survival rate for the 28 patients was 28.6%. Major side effects of MVP were leukopenia, thrombocytopenia, pulmonary emboli, and thrombophlebitis, detected mainly during the first 20 to 24 weeks of treatment.     

Phase II trial of procarbazine, lomustine, and vincristine as initial therapy for patients with low-grade oligodendroglioma or oligoastrocytoma: efficacy and associations with chromosomal abnormalities.

PURPOSE: The purpose of this article is to determine the response rate and toxicity of PCV administered before radiation therapy in patients with newly diagnosed LGO/LGOA and to explore correlations between response with 1p/19q deletions and aberrant p53 expression. BACKGROUND: Despite prolonged survival of patients with low-grade oligodendroglioma (LGO) and oligoastrocytoma (LGOA), the majority will succumb to progressive disease. Because procarbazine, lomustine (CCNU), and vincristine (PCV) is active in patients with recurrent LGO/LGOA, we hypothesized that it would be beneficial as primary therapy. METHODS: Adult patients with residual tumor on magnetic resonance imaging scan following biopsy or subtotal resection of LGO/LGOA received up to six cycles of PCV. Radiation therapy (59.4 or 54.0 Gy) began within 10 weeks of completing chemotherapy or immediately if there was evidence of tumor progression on PCV. Tumor tissue was analyzed by fluorescent in situ hybridization for 1p and 19q deletion and by immunohistochemistry for p53 expression. RESULTS: Eight of 28 (29%) and 13 of 25 (52%) eligible patients demonstrated tumor regression as assessed by the treating physician and a blinded central neuroradiology reviewer, respectively. Myelosuppression was the predominant toxicity. Loss of 1p and 19q were associated with LGO but not LGOA (P =.009), were inversely associated with p53 detection, and were not associated with response to PCV (possibly because of the small sample size). CONCLUSION: PCV produces tumor regressions in a meaningful proportion of patients with LGO/LGOA. Toxicity, especially myelosuppression, is significant. Loss of 1p and 19q seems limited to patients with pure LGO and is inversely related to p53 alterations.