Autologous Bone Marrow Transplantation - Blog Science Connections

International NHL Trial 337
disparity in selection criteria, statistical methods, and treatment modalities.
Only a randomized clinical trial can properly address the question.
METHODOLOGICAL CHOICES
Patient Selection
The theoretical target population is the group of patients with high-grade
or intermediate non-Hodgkin's lymphoma who are in relapse. To take into
account ethical and methodological considerations, investigators must
restrict admission to a responding patient group. Only those in sensitive
relapse after prior complete response will be included. In addition, only
patients who can receive either treatment without major risks (having no
cardiac, pulmonary, renal, or hepatic dysfunction and being below 60 years of
age) will be treated. No heavily pretreated patients (none with more than a
second relapse or previous doxorubicin chemotherapy) should be allowed to
participate. These criteria will produce a large subset of the theoretical target
population. However, restrictions about chemosensitivity exclude patients,
approximately 50%, who could be treated with ABMT and not with conventional
chemotherapy (i.e., those in resistant relapse).
Only patients who respond to salvage conventional therapy can be
included and randomized. The selection procedure of patients must be
divided into two phases, the preinclusion phase (two courses of conventional
chemotherapy) and the inclusion phase. If there is a complete response (CR)
or partial response (PR) after two courses of chemotherapy and if all selection
criteria are met, the patient is included and his therapy selected by
randomization. This selection plan includes only responders in the trial, and
all included patients are to be evaluated in their group.
Study Design (Fig 1)
Fundamental principles of controlled clinical trials are now well
established (4). Ideally, all patients eligible for the study should be assigned in
a random fashion to one of the study groups, and treatment should be
administered without delay. Thereafter, follow-up procedures and assessment
of study end points should be performed identically for all treatment
groups. Double-blind procedures are recommended for use, whenever
possible, to prevent follow-up and evaluation biases. For statistical purposes,
after randomization no patient can be withdrawn from his original treatment
group. Procedures should be designed to accommodate both methodological
considerations and practical constraints.
Randomization
Treatment must be administered as close as possible to randomization
(a delay between the second DHAP course and the next will theoretically be 28
days). However, it is necessary to inform the patient about the next treatment