8 2 A b s t r a c t s

easily and cheaply measured and with ~mportant and val,dated prognostic lntormatlon The use of randomized trials to prove the merits of such an attitude and to allow therapeutzc progress leads one to build prognostic classifications Within a prognostic class, one compares. with appropriate sample sizes, all or only a subset ot the treatments but adlacent prognostic classes receive at h_'ast one common treatment We have, set up two cooperative randomized studies of this kind (chronic lymphocytic leukemia, melanoma)

Use of a Natural History Phase for the Design of Trials for Duchenne Muscular Dystrophy (DMD) C o l l a b o r a t w e I n v e s t l g a t x o n ot D u c h e n n e D y s t r o p h y G r o u p , Washington Umvcrs;ty, St Louts, Mtssourt (P52) A collaborative s tudy ot DMD included a one-year natural h~story phase to chart the disease progress ion in boys of varying ages Since no single oblect~ve measurement provided an acceptable parameter tot the evaluation of therapeutic ethcacy, a variety ot laboratory meas- urements , functional g radmgs , and ratings of muscle strength and range ot motion data were collected for 100 patients on 8 visits spaced over a one-year interval lntra- and mterpatlent differences were evaluated in order to p rowde tmal design parameters An a~erage ot muscle strength evaluations at each time pemod proved to be particularly attrachve because ot ~ts reproducibf l l tyand hneanty wzth age The measurements over time allowed us t oe xa lua t e the ~atlhty of extended basehne periods m order to establish lndiwdual rates ot progression ot DMD This natural his tory phase also allowed tor the estimation of the expected changes in the parameters over time tacihtatmg sample s~ze calculations tor varying trial lengths, v~s~t frequencies, and outcome measures A one-year trial w~th quarterly ,.~s~ts demonstra ted acceptable power tor an evaluation ot Leuclne w~th 100 patients

Unreliability of Relapse Frequency as Predictor of Long Term Survival in Adjuvant Breast Cancer R o w a n C h l e b o w s k t , J o h n W e m e r , Vic tor R y d e n , a n d J o s e p h B a t e m a n , The Western Cancer Study Group, Los Angeles, Cahforma (P53) At present, clinical trials revolving adluvant therapy in breast cancer are commonly interpreted u smg early differences m r e l a p s e t r e q u e n c y a s e n d p o m t Begmmng m 1974, patients undergo- mg mastectomy at high risk tor recurrence (~4 nodes *) were randomized to receive either 5- FU or the drug combinat ion CMF tor 12 months Median tollow up ot the 02 pahents now exceeds 66 months CMF s,gmticantly prevented early disease recurrence (3",, recurrence on CMF ~,~ 25% on FU at 12 months , p<001.) resulting m survival advantage during the initial 40 months Subsequent ly this difference was lost and relapse tree sur~lval (RFSI and overall survival at 5 5 years were

RFS % Su rv iva l

5 -FU 36% 61% CMF 47~,, 47%

The apparently paradoxical relat ionships between RFS and survival on FU was related to survival alter recurrence Pahents treated after recurrence hved slgmt~cantly longer on the FU compared to CMF arm (median <69 mon ths vs 31 months , p < 0 05) These results suggest that long term survival m adluvant breast cancer tmals may not be accurately predLcted by early differences m disease recurrence

Protocol for Protocols H e l e n J G o l e n z e r , Mayo Comprehenswe Cancer Center, Rochester, Minnesota (P54) In order to conduct a good chmcal trial, a well thought out, al l-comprehensive protocol has to be developed and presented m an unders tandable , logical manner , covering all aspects necessary to achieve the desLred goals To make this task eas~er for the pr imary investigator, we have developed at the Mayo Chmc Oncology Department a structured, detailed outline for