Biomedical subjects

S F Dent

Publications and source records attributed to S F Dent.

3 recordsLinked to original sources

PubMed2000

Second primary malignancies following the treatment of early stage ovarian cancer: update of a study by the National Cancer Institute of Canada--Clinical Trials Group (NCIC-CTG).

BACKGROUND: Ovarian cancer is the leading cause of death from gynecological malignancies and the fourth most frequent fatal malignancy in women. Despite improved surgical techniques as many as 20% of women with early stage disease will eventually relapse and die from their disease. The post-operative management of these women remains controversial. Here we present the long term follow-up data of our previously published study, as well as the incidence of second primary malignancies in these women. PATIENTS AND METHODS: Two hundred fifty-seven eligible patients with stage I, IIA 'high risk' ovarian carcinoma and IIB, IIIO (disease confined to pelvis) were randomized to either whole abdominal radiotherapy 2.250 rads in ten fractions (107 patients), melphalan 8 mg/m2/d x 4 weeks x 18 courses (106 patients) or intraperitoneal chromic phosphate 10-20 mCi (44 patients). All patients were initially treated with pelvic radiotherapy. RESULTS: Overall survival estimates at 10 years were: 45% in the whole abdominal radiotherapy arm; 49% in the melphalan arm and 50% in the intraperitoneal chromic phosphate arm (P = 0.30). Relapse-free survival estimates at 10 years were: 50% in the whole abdominal radiotherapy arm, 62% in the melphalan arm and 51% in the chromic phosphate arm (P = 0.147). Long term follow-up has not demonstrated a significant difference between treatment arms. Second primary malignancies developed in 29 women (11%) after 2,229 person years of follow-up. This compares to 18.7 second primary malignancies which would have been expected in this group of age-matched controls and was statistically significant (P = 0.018). There was no significant difference in the total number of second primary malignancies between treatment arms. Melphalan appeared to be associated with an increased risk of developing leukemia/myelodysplastic syndrome compared to the whole abdominal radiotherapy arm (P = 0.06). CONCLUSIONS: Long-term follow-up has not demonstrated a significant difference in overall or disease free survival between treatment arms. An excess of second primary malignancies (35%) was observed suggesting that lifelong surveillance is required in this population. Further research with newer treatment programs are needed to improve the cure rates in this population.

Antineoplastic Agents, Alkylating↗

PubMed1996

Phase I trial design: are new methodologies being put into practice?

BACKGROUND: The primary goal of phase I studies is to efficiently and accurately determine the recommended dose of a new agent for further investigation. Issues of concern ranging from the ethics of these trials to selection of starting dose and rapidity of dose escalation, have led to suggested modifications of the traditional phase I design. We wanted to assess the frequency with which these new approaches are being applied to recent phase I trials and, if possible, their impact. METHODS: Reports of phase I trials of single agent cytotoxics published between 1993 and 1995 were identified by computer search and review of cancer journals. Data on starting dose, toxicology, dose escalation method, definition of dose limiting toxicity (DLT), actual maximum tolerated dose (MTD) and recommended phase II dose were abstracted. RESULTS: Reports of 46 phase I trials were identified: 27 were the first clinical studies of 17 new cytotoxic agents (group A) and 19 were repeat studies of 14 agents (group B). Starting doses in group A were based on preclinical animal toxicology (usually mouse or dog) and for group B on previous clinical experience. Dog toxicology appropriately influenced starting dose in 3 of 6 trials. The majority of group A (19/27) studies employed modified Fibonacci dose escalation; group B studies commonly escalated doses by fixed increments. The definition of DLT was highly variable across studies. MTD was usually defined as the dose level at which > 2/6 patients experienced DLT but several studies required 3-4/6 patients. In 30 trials, the recommended phase II dose was one dose level below the MTD; but in 10 trials the terms MTD and recommended phase II dose were considered synonymous. CONCLUSION: Despite proposed new methodologies (particularly dose escalation) for phase I trials, very few are being employed in practice. A concerted effort should be made to prospectively evaluate these to determine which provides the best combination of safety and efficacy. In addition, the lack of standardization in the definition of limiting toxicity is surprising. Those involved in drug development should strive for agreement on the acceptable degree of toxicity for phase II dose selection.

Antineoplastic Agents↗

PubMedDate not supplied

Phase II study of troxacitabine (BCH-4556) in patients with advanced non-small-cell lung cancer.

Troxacitabine. a promising new L-nucleoside, inhibits DNA polymerase and leads to complete DNA chain termination. The National Cancer Institute of Canada Clinical Trials Group (NCIC-CTG) conducted a phase II study to assess the efficacy and toxicity of troxacitabine in untreated patients with advanced non-small-cell lung cancer (NSCLC). Previously untreated patients were eligible if they had inoperable stage IIIB or IV NSCLC, ECOG PS < or = 2, adequate hematology and biochemistry, and at least one bidimensionally measurable lesion. Patients with prior malignancy or brain metastases were excluded. Troxacitabine (10 mg/m(2)) was administered intravenously over 30 minutes every 3 weeks. Between June 1999 and May 2000, 17 eligible patients received treatment. Patient characteristics included: median age 64 years; female 41%; stage IV (94%); PS 0 (12%), 1 (59%), and 2 (29 %), 3 or more disease sites (59%). In 17 patients, there were 8 stable disease, 9 disease progression, and no objective responses. Median duration of stable disease was 3.6 months (range = 2.0-7.1). A total of 56 cycles were administered (median = 3), and 88% of patients received 90% or more of the planned dose intensity. The majority (82%) of patients experienced skin rash. Hematologic and biochemical toxicities, grade 3/4 (%) were: granulocytopenia (41), anemia (12), thrombocytopenia (6), and hyperglycemia (6). Troxacitabine appears to have little activity in NSCLC in the dose and schedule tested.

Aged↗