Comparison of local versus central tumor measurements in a multicenter cancer trial

Tumour size measurement in an oncology clinical trial: comparison between off-site and on-site measurements

AIM

To evaluate the degree of variability between lesion measurements obtained by a single observer compared with multiple observers, and in selected cases evaluate which of the two measurements more accurately represented the lesion size.

MATERIALS AND METHODS

In this study we compared the performance of a single off-site observer to multiple on-site observers during measurement of 300 abdominal and thoracic lesions. Lesion measurements that were larger than 1cm(2), differed by more than 50%, but by less than 100%, were compared by a single adjudicator, who was blinded to the measurement source (n=46).

RESULTS

Measurements of the 300 lesions differed by an average of 109% (SD 251%). Of 266 lesions larger than 1cm(2), results of the single observer compared with multiple observers differed by more than 10% for 249 lesions, more than 30% for 169 lesions, more than 50% for 126 lesions, and more than 100% for 66 lesions. Forty-six lesions were compared by the adjudicator. The adjudicator selected the measurement of the single observer for 37 lesions (80.4%), and the measurement determined by one of the multiple observers for nine lesions (19.6%; p=0.00002).

CONCLUSION

Measurement of lesion size by a single observer compared with multiple observers reveals a high degree of variability. An adjudicator selected the measurement of the single observer more frequently than that of multiple observers, with statistical significance. These findings suggest that studies designed to quantify imaging features should limit the number of observers.

The Department of Veterans Affairs' unique clinical cancer research effort

Without organized clinical trials, we are doomed to repeat our mistakes endlessly. There are many genuine conflicts of interest intrinsic to clinical research. Some of these arise from the necessity of admitting that we as physicians do not know the best way to treat every disease or each patient and that all treatments currently available for this patient's disease are suboptimal. With humility and honesty, these conflicts of interest can be overcome. Surmounting other more palpable ones, however, is equally challenging. Supporting the participation of our patients in clinical trials requires a practical reconfiguration of practice patterns, different and more record keeping, and the surrender of autonomy. Each of these facts has economic implications. Practitioners who are paid according to the specific services they provide risk both significant income loss and cost increase by participating in clinical trials. The Department of Veterans Affairs is a charter member of the cancer clinical trials establishment and the originator of a long string of important firsts in cancer research. The nature of the VA system eliminates or diminishes the impact of many of the conflicts of interest that hinder clinical trial participation. This globally budgeted comprehensive system, which theoretically is responsible for the care of more citizens than is the entire Canadian national health service, is an unique clinical research resource. Some of the high points of the VA contributions to cancer treatment development are listed in this paper. Hopefully, this overview makes the point that the VA clinical research enterprise is a treasure that can ask critical questions that, because of irresolvable economic conflicts of interest, can be asked neither in the fee-for-service nor the prepaid health maintenance settings. This clinical cancer research resource must be nurtured and supported, and it must continue to address critical questions that it alone can answer.

Chronic calcium antagonist use in carcinoma of the lung and colon: a retrospective cohort observational study

Detailed records were maintained prospectively of all medications taken by 719 patients with advanced carcinoma of the lung or colon. Of this total, a cohort of 19 patients was identified who had ingested incidentally either nifedipine, diltiazem, verapamil, or trifluoperazine in standard therapeutic doses for a minimum of one month and a mean of 5.8 months and median of three months. Treatment with these calcium antagonists was well tolerated and, upon comparison with otherwise comparable patients who did not ingest a calcium antagonist, appeared to be associated with certain favorable outcomes, including delayed tumor progression and prolonged survival. These preliminary findings suggest that beneficial effects of such drugs observed with chronic treatment in experimental animal tumor models may occur in human disease and that definitive prospective, randomized, clinical trials of calcium antagonists administered continuously in ordinary therapeutic doses are both feasible and justified.