The Canadian journal of oncology最新文献

Docetaxel (Rhône-Poulenc Rorer Pharmaceuticals Inc.), a new and novel taxoid, is a potent antitumor agent that promotes microtubule polymerization and inhibits tubulin depolymerization, resulting in the inability of cells to replicate. Docetaxel exhibits a broad spectrum of antitumor activity in vitro and in vivo. Phase II trials indicate a high degree of activity against advanced breast cancer, including anthracycline-resistant disease, and significant activity in advanced non-small cell lung, ovarian, head and neck, and pancreatic carcinomas and potential activity against other tumors as well. The recommended dosing regimens is 100 mg/m2 administered intravenously over one hour, with cycles repeated every three weeks. The most frequent hematologic side effect is neutropenia. Most nonhematologic side effects are generally mild to moderate in severity. Dermatologic side effects occur frequently, and fluid retention occurs with cumulative dosing. Premedication regimens with corticosteroids prevent significant hypersensitivity reactions and appear to be of value in ameliorating skin reactions and fluid retention. Docetaxel is currently being intensively evaluated in a phase II/III clinical program both as a single agent and as part of combination chemotherapy regimens and should prove to be clinically useful for a number of tumors.

Background: Age is known to have an important influence on survival in non-Hodgkin's lymphoma (NHL). This observation and the relationship of age to other prognostic factors are of interest in designing treatment programs for these patients. This study was conducted to investigate the relationship of age to other known prognostic variables and survival in NHL.

Patients and methods: Data on clinical features, treatment, response, survival and cause of death from 547 patients with NHL diagnosed between 1980 and 1989 were collected and analyzed by age group. Multivariate analysis of prognostic factors and a survival comparison to an age and sex matched control population were performed.

Results: Survival curves for 5-year age groups up to and including age 60-64 years were similar, after which a major effect of age upon survival was apparent. When groups aged < 65 years and > and = 65 years were compared, there were similar proportions of most known prognostic factors, except for a higher proportion with increased lactate dehydrogenase (LDH) levels and extranodal disease in older patients. When analyzed by age group, older patients had a lower response rate to initial therapy and salvage treatments. In younger patients, several recognized prognostic variables were found to lack significance.

Conclusions: Prognostic variables differ between younger and older patients with NHL. Age, histology, LDH elevation and gender are less important in younger patients; only bulky disease is more important than in older patients. A lower response rate, poor response to salvage therapy and excess mortality, often due to concurrent diseases, were apparent in older patients. Age is a significant prognostic factor only in patients age > and = 65 years.

A simple mathematical model based on queueing theory is introduced, and used to obtain a sensitive measure of the capacity of a radiation therapy centre to provide service. The model illustrates the relationships among the relevant variables: the patient waiting time, the number on the waiting list, the rate at which requests for radiation therapy are received and the rate at which courses of treatment are commenced. In particular, the rate at which the waiting time increases is equal to the difference between the request rate and the start rate, expressed as a fraction of the start rate, and is therefore a measure of the deficiency in service capacity of a facility. A study of the records of patients treated on the linear accelerators of the Tom Baker Cancer Centre from January 1991 to June 1994 shows that this relationship holds to a high degree of accuracy for average values of the various parameters in spite of the considerable variation in these values, and particularly variation in the individual waiting times. This finding suggests that such an approach would be useful in assessing and comparing the performance of radiation therapy facilities.

A number of different palliative radiotherapy techniques and fractionation schedules have been used in the UK over the past several years. In an attempt to standardize treatment practices, a handful of studies have been conducted in recent years compiling basic demographic data on the use of palliative radiotherapy as well as response data for the various techniques currently in use. In one study conducted at Mount Vernon Hospital, just outside of London, Maher and colleagues collected data on 425 consecutive patients given radiotherapy during a six-week period in 1988. Of those, 211 (49.6%) patients received radical treatment for long-term tumor control, and the remaining 214 (50.4%) patients received palliative treatment for symptom relief in the case of incurable cancer. Of the 214 patients treated with palliative radiotherapy, 90 (42%) patients were treated for bone secondaries, 63 (29%) patients for primary carcinoma of the bronchus, 12 (6%) patients for brain secondaries and 49 (23%) patients for other miscellaneous reasons. There is evidence that in the last few years British practice in palliative radiotherapy has changed substantially, largely as a result of the findings of recent clinical trials. This review will summarize the data relating to the radiotherapeutic management of bone secondaries, advanced lung cancer and cerebral metastases.

In fact that radiation therapy is often the most effective means of palliating symptoms caused by cancer is well recognized in the United States. Estimates of the proportion of patients treated in the US with radiation therapy who are treated for palliative rather than curative intent range from 15% to 50% and depend on the geographic location, cancer incidence, referral patterns, etc. All radiation oncologists in the United States have had significant experience with the use of palliative radiation therapy during their residency and in their practice. Estimates from patterns of care studies indicate that over 250,000 patients were treated with palliative radiation therapy at a cost of between $1.0 and $1.8 billion in 1994. The scope of this presentation will cover four aspects of palliative radiation therapy in the United States: 1. existing practice patterns; 2. factors affecting treatment patterns; 3. the cost of palliative radiation therapy; and 4. present research and guidelines developments efforts.

We have prospectively gathered information contained in the Ontario Cancer Foundation computerized clinical data base to provide a quantitative description of palliative radiotherapy workload and fractionation practices in the management of non-small cell lung cancer over a ten-year period. We found that the proportion of radiotherapy fractionations used in palliation has declined steadily between 1984 and 1991. In the palliation of non-small cell lung cancer there has been a steady decline in the number of fractions given per course of treatment in the management of chest disease, bone metastases, and brain metastases with significant variation both between and within individual cancer treatment centres.

Painful bone metastases are a clear indication for the use of radiotherapy, with reported response rates of up to 85% of patients treated. In an attempt to define the optimal use of palliative radiotherapy when used in this situation, the data for the efficacy, toxicity and choice of dose and fractionation are reviewed. Although there have been some recent trials demonstrating the value of hypofractionated radiation therapy, half-body irradiation and 89-strontium, in general there is a lack of information in this clinical area, particularly on the duration of beneficial effect and on treatment toxicity. The available data suggest that single-fraction radiation is as effective as short-course fractionated treatment, and may be isotoxic when 5HT3 antagonists are used. Future implications for research are discussed.

Economic evaluations can be useful in decision making regarding allocation of scarce health care resources such as radiation therapy. However, assessment of treatment efficacy must be performed in addition to economic evaluations if proper resource allocation decisions are to be made. Economic evaluations cannot and should not relapse properly conducted clinical trials-particularly in the area of palliative care.