Edward S. Newlands

Temozolomide: a review of its discovery, chemical properties, pre-clinical development and clinical trials

*Department of Medical Oncology, Chafing Cross Hospital, Fulham Palace Road, London W6 8RF, U.K. t Cancer Research Campaign Experimental Cancer Chemotherapy Research Group, Cancer Research Laboratories, Department of Pharmaceutical Sciences, University of Nottingham, Nottingham NG7 ZRD, U.K.

HISTOPATHOLOGY IN THE PREDICTION OF RELAPSE OF PATIENTS WITH STAGE I TESTICULAR TERATOMA TREATED BY ORCHIDECTOMY ALONE

Drugs Dynamics Institute, College of Pharmacy, University of Texas at Austin, Austin, TX 78712-7074, U.S.A.

Choriocarcinoma and partial hydatidiform moles

259 patients with stage I non-seminomatous germ-cell testicular teratoma who were treated by orchidectomy alone and monitored at one often centres in the United Kingdom were followed for a median of 30 months. 62 of the 70 relapses occurred in the first 18 months after orchidectomy. The 2-year relapse-free rate was 74%, falling to 68% at 4 years. Histological sections from 233 of the orchidectomy specimens were reviewed centrally. Four features independently predicted relapses: invasion of testicular veins, invasion of testicular lymphatics, absence of yolk-sac elements, and presence of undifferentiated tumour. An index, based on the number of these features observed, identified a high-risk subgroup of 55 patients who had a 42% relapse-free rate at 2 years.

Temozolomide: A new oral cytotoxic chemotherapeutic agent with promising activity against primary brain tumours

BACKGROUND Partial hydatidiform moles (PMs) rarely require chemotherapy and have never previously been proven to transform into choriocarcinoma, the most malignant form of gestational trophoblastic disease (GTD). Consequently, some have questioned whether women with PMs need human chorionic gonadotropin (hCG) follow-up. Here, we investigate whether PMs can transform into choriocarcinomas. METHODS Patients with a PM who developed a subsequent choriocarcinoma were identified from our GTD database. The histology of both PM and ensuing choriocarcinoma was reviewed and flow cytometry used to verify the triploid status of the PMs. To determine whether the choriocarcinoma arose from the PM, DNA from the PM and choriocarcinoma in each patient was compared using microsatellite polymorphisms. FINDINGS Of the 3000 patients with PM, 15 required chemotherapy for persisting GTD. This was identified as choriocarcinoma in three cases. In one patient, the local pathologist could not differentiate between a PM or a hydropic abortion and neither central histological review nor hCG follow-up were obtained. This patient nearly died before the diagnosis of choriocarcinoma was made. Fortunately, the local pathologists correctly diagnosed PM in the two other patients who were then registered for hCG follow-up. Some months later, the hCG was rising and repeat uterine evacuation revealed choriocarcinoma. The PM was confirmed to be triploid in all three cases and genetic analysis showed that the subsequent choriocarcinomas contained identical single maternal and two paternal alleles at several independent loci. INTERPRETATION Our results show that PMs can transform into choriocarcinoma. All patients with suspected PM should be reviewed centrally and, if confirmed, need hCG follow-up.

EMA/CO for High-Risk Gestational Trophoblastic Tumors: Results From a Cohort of 272 Patients

Temozolomide, a new oral cytotoxic agent, has been given to 28 patients with primary brain tumours. Treatment was given at a dose of 150 mg/m2/day for 5 days (i.e. total dose 750 mg/m2) escalating, if no significant myelosuppression was noted on day 22, to 200 mg/m2/day for 5 days (i.e. total dose 1000 mg/m2) for subsequent courses at 4 week intervals. A major improvement in computer tomography (CT) scan was noted in 5/10 patients with astrocytomas recurrent after radiotherapy, with a major clinical improvement but minor improvement on CT scan in one further patient. Reduction in the size of the CT lesion was also observed in 4/7 patients with newly diagnosed high grade astrocytomas given 2-3 courses of temozolomide prior to irradiation. 1 patient with recurrent medulloblastoma had a clinical response in bone metastases. Temozolomide was well tolerated with little subjective toxicity and usually predictable myelosuppression and is a promising new drug in the treatment of primary brain tumours.

Current and future developments in the use of temozolomide for the treatment of brain tumours.

PURPOSE To evaluate the results of etoposide, methotrexate, and dactinomycin alternating with cyclophosphamide and vincristine (EMA/CO) chemotherapy in women with high-risk gestational trophoblastic tumors (GTT) and to document the middle- and long-term toxicity of the regimen. PATIENTS AND METHODS A total of 272 consecutive women with high-risk GTT, including 121 previously treated patients, were treated with weekly EMA/CO. The median follow-up duration is 4.5 years (range, 1 to 16). RESULTS The cumulative 5-year survival rate is 86.2% (95% confidence interval, 81.9% to 90.5%). No deaths from GTT have occurred later than 2 years after the end [corrected] of EMA/CO. In a multivariate model, adverse prognostic factors were the presence of liver metastases (P < .0001), interval from antecedent pregnancy (P < .0001), brain metastases (P = .0008), and term delivery of antecedent pregnancy (P = .045). There were 11 (4%) early deaths, while 213 patients (78%) achieved a complete remission. Forty-seven (17%) developed drug resistance to EMA/CO, of whom 33 (70%) were salvaged by further cisplatin-based chemotherapy and surgery. Two women developed acute myeloid leukemia, two cervical malignancy, and one gastric adenocarcinoma after EMA/CO. More than half (56%) of the women who had fertility-conserving surgery and who have been in remission at least 2 years have become pregnant since the completion of EMA/CO, with 112 live births, including three infants with congenital abnormalities. CONCLUSION EMA/CO is an effective and well-tolerated regimen for high-risk GTT. More than half of the women will retain their fertility; however, there is a small but significant risk of second malignancy.

Low-risk persistent gestational trophoblastic disease: Outcome after initial treatment with low-dose methotrexate and folinic acid from 1992 to 2000

Brain tumours comprise only 2% of all adult cancers, but they are among the most debilitating malignant diseases. Temozolomide, an alkylating agent that can be administered orally, has been approved for the treatment of recurrent malignant glioma on a daily schedule for 5-day cycles. Continuous administration schedules with a higher dose intensity are being explored, but an improvement in efficiency remains to be shown. The benefit from temozolomide given as a single agent in recurrent disease will be several weeks at best. This drug is therefore now undergoing clinical testing as neoadjuvant chemotherapy or with concomitant radiotherapy in patients with newly diagnosed glioma. Several phase I trials are investigating the combination of temozolomide with other agents active against brain tumours. This review briefly summarises the pharmacological background and clinical development of temozolomide and focuses on current and future clinical exploration of this drug for the treatment of brain tumours.

Etoposide and Cisplatin/Etoposide, Methotrexate, and Actinomycin D (EMA) Chemotherapy for Patients With High-Risk Gestational Trophoblastic Tumors Refractory to EMA/Cyclophosphamide and Vincristine Chemotherapy and Patients Presenting With Metastatic Placental Site Trophoblastic Tumors

PURPOSE We have simplified the treatment of gestational trophoblastic disease (GTD) in order to reduce the number of patients exposed to potentially carcinogenic chemotherapy. Patients who score 0 to 8 on the Charing Cross scoring system are classified as low-risk and receive methotrexate (MTX) and folinic acid (FA), whereas those who score higher than 8 are classified as high-risk and receive the etoposide, methotrexate, and dactinomycin (EMA)/cyclophosphamide and vincristine (CO) regimen. PATIENTS AND METHODS Between 1992 and 2000, 485 women with GTD were commenced on MTX/FA at Charing Cross Hospital, London, United Kingdom. If patients developed MTX resistance or toxicity, treatment was altered according to the level of beta human chorionic gonadotropin (hCG). If serum hCG was < or = 100 IU/L, patients received dactinomycin; if hCG was greater than 100 IU/L, patients received EMA/CO. RESULTS The median duration of follow-up was 4.7 years. Overall survival was 100% and the relapse rate was 3.3% (16 of 485 patients). hCG values normalized in 324 (66.8%) of 485 patients with MTX alone, whereas 161 (33.2%) of 485 patients required a change in treatment, 11 because of MTX toxicity and 150 because of MTX resistance. Sixty-seven patients changed to dactinomycin, of whom 58 achieved normal hCG values, and nine required third-line chemotherapy with EMA/CO. hCG values normalized in 93 (98.9%) of 94 patients who changed directly to EMA/CO from MTX. CONCLUSION Single-agent dactinomycin has activity in patients with low-risk GTD who develop MTX resistance and whose hCG is low. Simplifying the stratification of GTD into two classes (low- and high-risk) does not compromise overall outcome and may reduce the risk of second tumors.

Combination but not single-agent methotrexate chemotherapy for gestational trophoblastic tumors increases the incidence of second tumors.

PURPOSE To evaluate the results of etoposide, cisplatin/etoposide, methotrexate, and actinomycin D (EP/EMA) chemotherapy in patients with gestational trophoblastic tumors (GTTs), who have relapsed after or who have become refractory to EMA/cyclophosphamide and vincristine (CO) chemotherapy, and in patients presenting with metastatic placental site trophoblastic tumors (PSTTs). PATIENTS AND METHODS We have treated a total of 34 patients with GTT and eight patients with metastatic PSTT with the EP/EMA chemotherapy schedule. RESULTS Twenty-two patients received EP/EMA because of apparent drug resistance to EMA/CO, and because the human chorionic gonadotropin (hCG) was near normal, they were not assessable for response. Twenty-one of these patients (95%) are alive and in remission. In the group where the hCG was high enough to confirm a response (greater than one log fall in hCG) to EP/EMA, all 12 patients responded and nine of these patients (75%) are alive and in remission. We have treated three patients with PSTT where the interval from antecedent pregnancy was less than 2 years, and all patients (100%) are alive and in remission. We have treated five patients where the interval from antecedent pregnancy was greater than 2 years and one fifth (20%) remain in remission. The survival for patients with GTT is 30 (88%) out of 34 patients and four (50%) out of eight patients for PSTT, giving an overall survival for these two cohorts of 34 (81%) out of 42 patients. The toxicity of this schedule is significant, with grade 3 or 4 toxicity (National Cancer Institute common toxicity criteria) recorded in hemoglobin (21%), WBC (68%), and platelets (40%). The role of surgery in this group of patients is important and contributed to sustained remission in five patients (23%) and possibly helped an additional seven patients (32%). CONCLUSION EP/EMA is an effective but moderately toxic regimen for patients with high-risk GTT who become refractory to or relapse from EMA/CO chemotherapy. Also, EP/EMA clearly has activity in patients with metastatic PSTT.

IN VITRO EVALUATION OF TEMOZOLOMIDE COMBINED WITH X-IRRADIATION

PURPOSE No increase in second tumor incidence was found in a previous analysis of women treated with chemotherapy for gestational trophoblastic tumors (GTT). More patient years at risk enabled a further analysis of the risk of second tumors to be performed in the 1,377 women treated in this until up to 1990. PATIENTS AND METHODS Health questionnaires were returned on 93.3% of patients who successfully completed chemotherapy and were living in the United Kingdom. The remainder were flagged for death or developing further cancers by the Office of Population Census and Surveys and by the Thames Cancer Registry. Incidence density analysis was performed based on 15,279 person-years of observation available. Standardized incidence ratio (SIR) was used to estimate the relative risk (RR) of second tumors associated with the treatment. To calculate the expected number, the actual incidence rates observed by the Thames Cancer Registry during the same calendar period of observation were used. RESULTS An overall 50% excess of risk (RR = 1.5; 95% confidence interval [CI], 1.1 to 2.1; P < .011) was observed: there were 37 second tumors, when 24.5 were expected. For specific second tumors, the risk was significantly increased for myeloid leukemia (RR = 16.6; 95% CI, 5.4 to 38.9), colon (RR = 4.6; 95% CI, 1.5 to 10.7), and breast cancer when the survival exceeded 25 years (RR = 5.8; 95% CI, 1.2 to 16.9). The risk was not significantly increased among the 554 women receiving single-agent therapy (RR = 1.3; 95% CI, 0.6 to 2.1). Leukemias only developed in patients receiving etoposide plus other cytotoxic drugs. CONCLUSION This study suggests that there is a slight increased risk of second tumors after sequential or combination chemotherapy for GTT. This has become apparent since the introduction of etoposide and longer follow-up.