In the present study the prognostic value of both DNA ploidy and the proliferative activity of tomour cells were studied in a series of 76 consecutive patients suffering from gastric tumours. DNA ploidy and the proliferative index (as measured by the percentage of S-phase cells) were determined by flow cytometry using fresh tumour specimens.The presence of DNA aneuploid clones by flow cytometry was detected in 62% of the cases (mean DNA index of 1.63 ± 0.46; range 1.08–2.92), the mean proportion of S-phase cells being of 18.4 ± 11.5%. In comparison with diploid cases, aneuploid tumours showed a higher proliferative activity (cases with more than 15% S-phase cells: 18.4% versus 6.1%, p = 0.0001) as well as a higher incidence of node involvement (95% versus 68%, p = 0.001). By contrast, no significant differences were detected with respect to sex, age, histologic grade and type, clinical stage, tumour size and the incidence of extranodal involvement.Upon grouping the patients according to the proportion of S-phase cells no significant differences were observed for the clinical and biological parameters explored except for an association between a high percentage of S-phase cells and the presence of DNA aneuploidy (40% versus 96%, p = 0.0001). Regarding survival the presence of DNA aneuploidy was significantly associated with poor outcome as compared to the diploid cases (median of 15 versus 26 months, p = 0.005). By contrast, the proportion of S-phase cells did not predict patients’s outcome.Multivariate analysis of prognostic factors showed that the presence of DNA aneuploidy (p = 0.003) together with the histologic type (p = 0.03) and the existence of extranodal metastases (p = 0.05) were the best combination of prognostic factors for survival prediction.

Pancreatic ductal adenocarcinoma was induced in female Syrian golden hamsters by injecting Nnitrosobis(2-oxopropyl)amine (BOP) once a week at a dose of 10 mg per kg of body weight for 18 weeks. Hamsters were then treated with somatostatin analog D-Phe-Cys-Tyr-D-Trp-LysVal-Cys-Trp-NH2 tTo whom reprint requests should be addressed at: Veterans Ad-

Possible protective effects of the agonist [DTrp6]LH-RH (analog of luteinizing hormone-releasing hormone in which Gly-6 is replaced by D-tryptophan) and antagonist N-Ac-[D-Phe(pCl)1'2,D-Trp3,D-Arg6,D-Ala10]LH-RH against testicular damage caused by x-radiation were investigated in rats. Three months after being subjected to xirradiation of the testes with 415 or 622 rads, control rats showed marked reduction in the weights of the testes and elevated levels of LH and follicle-stimulating hormone (FSH), indicating tubular damage. Histological studies demonstrated that, in testes of rats given 415 rads, most seminiferous tubules had only Sertoli cells and no germinal cells, and, in the group given 622 rads, the depression of spermatogenesis was even more marked. Rats pretreated for 50 days with LH-RH antagonist (1000 ,ug/kg of body weight per day) showed a complete recovery of testicular weights and spermatogenesis 3 months after 415 rads and showed partial recovery after 622 rads, and LH and FSH levels returned to normal in both of these groups. Thus, pretreatment of rats with LH-RH antagonist, by reversibly inhibiting gonadal function, protected the germinal cells of the testes against damaging effects of x-rays. Three experiments were also carried out in which the rats were pretreated for 1-2 months with long-acting microcapsules of the agonist [D-Trp6]LH-RH, liberating 25 ,ug of the agonist per day. Some rats were then subjected to gonadal irradiation with 415 or 622 rads and allowed a recovery period of 2-4 months.In spite of pretreatment with [p-Trp6]LH-RH, testicular weights were significantly lower and LH or FSH levels were elevated in the irradiated groups as compared with nonirradiated controls. The recovery of spermatogenesis was incomplete, and there was a decrease in the number of germinal cells after 415 rads and especially after 622 rads. On the basis of testicular weights, histology, and gonadotropin levels, it could be concluded that the agonist [D-Trp6]LH-RH did not protect the rat testes exposed to 622 rads and, at most, only partially protected against 415 rads. These results suggest that pretreatment with LH-RH antagonists and possibly agonists, might decrease the testicular damage caused by radiation and accelerate the recovery of reproductive functions.

The combination of hormonal treatment based on a long-acting delivery system for the agonist [6-D-

Histopathologic changes produced during the treatment of Dunning R3327 prostate cancer with new superactive somatostatin analogs (RC-121 and RC-160) and D-Trp-6 analog of luteinizing hormone-releasing hormone agonist (D-Trp-6-LH-RH) were studied. A significant reduction of the tumor weight could be observed in all treated groups, but the greatest decrease in the tumor volume was seen in the groups receiving the combination of the somatostatin analog and D-Trp-6-LH-RH. Histologically, the treatments resulted in a loss of the tumorous glandular elements and the proliferation of the stromal cells. In the tumors treated with somatostatin analogs, the amount of connective tissue was greatly increased and was accompanied by the appearance of thick collagenous fibers. In the D-Trp-6-LH-RH treated groups, regressive changes in the epithelium were seen in addition to the proliferation of connective tissue. The greatest histologic improvement was observed in the group treated with the combination of RC-160 and D-Trp-6-LH-RH. This histopathologic evaluation clearly supports our contention that superactive analogs of somatostatin greatly potentiate the inhibitory effect of D-Trp-6-LH-RH on the growth of Dunning prostate tumors and may improve the clinical response in patients with prostate cancer.