Design of the COMS
The design of the COMS is characterized by:
- Multicenter organization
- Standard protocol followed in all centers for initial evaluation, patient entry and randomization, treatment, and follow-up
- Standard data collection forms designed specifically for the COMS
- Standard eligibility and exclusion criteria
- Scheduled follow-up of all patients at comparable intervals
- Random allocation of management strategy
- Central allocation of random assignment
- Informed consent according to COMS guidelines
- Certification of clinic personnel and clinical centers
- Central monitoring of radiation treatment
- Concurrent data processing
- Ongoing quality assurance and monitoring program for all aspects of Study operations
- Central data processing and analysis
- Central confirmation of the diagnosis from photoechograms, color photographs, and fluorescein angiograms
- Central histopathologic diagnosis for all patients whose eyes are enucleated
- Periodic reports on performance of all centers
- Periodic analysis of accumulating data for review by the Data and Safety Monitoring Committee
- Patient Enrollment and Informed Consent
- Adherence to the enrollment criteria is monitored at the Coordinating Center, the Echography Center, and the Photograph Reading Center.
Considerable attention is given to education of the patient and family members in order to assure that they understand the nature of the malignancy, the treatment options available, and the rationale for asking the patient to participate in a randomized trial. The patient education and orientation activities are important parts of the complete informed consent process and are described in detail in The COMS Manual of Procedures.
All patients enrolled in the COMS have a right to be informed regarding:
- The purpose of the study
- The fact that the management strategy is chosen at random from the two believed to be the best candidates on the basis of size of the tumor in the patient's eye
- The commitment to long-term follow-up that is being made by the patient
- The commitment to long-term care and attention being made by the COMS clinical center physicians and staff
In addition, the patient has a right to know how much the evaluation and treatment procedures cost, as in any health care setting, and that neither the patient nor the health insurer is expected to pay for research costs.
- Patient Follow-up
- A standard follow-up schedule is used for all patients enrolled in each substudy. The follow-up schedule and an overview of patient visits for evaluation and data collection purposes are given in The COMS Manual of Procedures. Patients enrolled in the randomized trials are followed for at least ten years after enrollment or to death.
- Sample Size
- The COMS investigators estimate that the randomized trial comparing enucleation with I-125 plaque radiation for medium melanomas will require about 2400 patients to be able to detect a 25% relative difference in cumulative five-year mortality with reasonable confidence. The sample size is subject to periodic review by the Data and Safety Monitoring Committee in order to check the accuracy of the assumptions on which it has been based and to make refinements as necessary. Enrollement in the trial for medium-sized melanoma is ongoing.
For the randomized trial comparing standard enucleation with enucleation preceded by external beam radiation for large melanomas, the investigators estimated that approximately 1000 patients were required. Accrual to the trial for large sized melanoma was closed in December 1995, with 1,003 patients enrolled.
- Study Outcomes
- The primary comparison of interest in each randomized trial is the difference between the two management groups with respect to all-cause mortality after entry into the COMS.
- Cancer-free and metastasis-free survival are based on the judgements of the Mortality Coding Committee regarding whether metastatic disease or other cancer was present at the time of death and is based on reports from the clinical centers of diagnosis of metastasis and other malignancies as well as on histopathologic review of tumor biopsies taken at the time of diagnosis of the matastasis or at autopsy.
- Years of useful vision is of interest for all patients, whether or not the Study eye is retained; visual acuity is assessed during each clinic visit for both the fellow eye and the Study eye, if present. For patients in the trial for medium tumors, visual status of the plaqued eye is followed in order to determine the impact of I-125 radiotherapy on visual ability. Vision of the fellow eye for patients in both trials is also measured in order to assess the risk of vision loss due to radiation to the Study eye.
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