•••••••••a l(al 
response followed by 47+ months of stable disease. Of the 10 skin test negative 
patients, none had a clinical response. 
ls_j 
A survival outcome for skin test positive versus negative patients is shown in Figure 
2. All the skin test negative patients had expired by 22 months while 4/8 skin test 
positive patients were alive at greater than 32 months. The survival times of these two 
groups differs with p = 0.03, by the generalized Wilcoxon (Breslow) test. 
Clinical investigators have had some success with vaccines for advanced 
malignant melanoma. Berd, Maguire, and Mastrangelo (12) used autologous 
melanoma tumor cells for their vaccine with BCG as the adjuvant and have reported 
responses in melanoma patients in the 16-20% range with some responses being 
complete remissions which were long-lasting. Mitchell and associates (5) have been 
evaluating an allogeneic vaccine derived from two cultured melanoma lines and then 
prepared as a subcellular lysate. As an adjuvant they employed the agent Detox. 
They have observed responses in 20-30% of the patients in the Phase I and Phase II 
studies. Morton and associates have used a 3-line allogeneic melanoma vaccine and 
have obtained responses in 19% of their patients (6). 
In colon cancer, Hanna and Hoover (13, 14) have conducted a prospective 
randomized study comparing surgical treatment only versus surgery followed by a 
vaccine of autologous tumor cells with BCG as the adjuvant. The survival outcome in 
these patients favored those receiving the vaccine at an early point when only 20 
patients had been entered in each arm. The full study with about 75 patients 
participating continues to demonstrate a significant recurrence-free survival and 
overall survival for those patients treated with vaccines following surgery. 
The study by Hanna and Hoover indicates the potential of the specific 
immunotherapy approach for the treatment of cancer. In order to attain a broader 
application for the treatment of cancer, we will need to move towards the use of a more 
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Recombinant DNA Research, Volume 15 
