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Bladder Cancer Recurrence by Implantation of Exfoliated Cells: Is gamma-Linolenic Acid an Effective Tumoricidal Agent?
PRINCIPLES OF ONCOLOGY, AND TUMORS OF BLADDER, PENIS AND URETHRA
susceptibilities to undergoing apoptosis. The aim of this study was to evaluate the effects of introduction of wild-type p53 or p2lWM1 ‘xP1( ~ 2 1on ) chemosensitivity of bladder cancer cells. Materials and Methods: The human bladder cancer cell line HT1376, which contains mutant p53 and p21 genes, was used in this study. 7 6 to cisplatin were The effects of adenoviral-mediated p53 or p21 gene transfer on sensitivity of ~ ~ 1 3cells analyzed both in vitro and in vivo. Results: The introduction of wild-type p53 gene into HT1376 markedly enhanced the sensitivity to cisplatin in vitro. Direct injection of the p53-adenoviral vector into subcutaneous HT1376 tumors established in nude mice, followed by intraperitoneally administration of cisplatin, induced massive apoptotic destruction of the tumors. In contrast, the sensitivity of HT1376 to cisplatin was not increased by the introduction of the p21 gene either in vitro or in vivo. Conclusions: These findings suggest that the combined regimen of adenoviral-mediated p53 gene transfer and cisplatin may become an efficient and powerful tool for treatment of bladder cancer.
Editorial Comment: A growing number of investigations using the principles and techniques of gene therapy to approach various urological cancers are appearing in the literature. The authors explore the possibility of combining chemotherapy with attempts to transfer p53 or p21 into urothelial cell lines as a means of restoring their capability of apoptosis (programmed cell death). A dose dependent, slight antiproliferative effect was demonstrated in vitro. Moreover, pretreatment of the cell lines with the p53 adenovirus vector appeared to enhance the sensitivity of these cells to the toxic effect of cisplatin, whereas pretreatment with the p21 adenovirus vector did not. In vivo studies, in which subcutaneous tumors were injected directly with p53 or p21 adenovirus and cisplatin was injected intraperitoneally, revealed a tumor inhibitory effect only with the p53 adenovirus vector. Gene therapy alone was not toxic to the cells in vivo. Whether this model is applicable to humans for treatment of organ confined, or possibly even of metastatic, disease is not addressed. However, a major objective in gene therapy studies remains, that is what to deliver clinically and how. Michael J. Droller, M.D.
Bladder Cancer Recurrence by Implantation of Exfoliated Cells: Is y-linolenic Acid an Effective Tumoricidal Agent?
L. 2. SOLOMON, A.M. JENNINGS,S. J. FOLEY, B.R. BIRCHAND A. J. COOPER,Departments of Urology, Southampton University Hospitals NHS Trust, Southampton and St. Mary’s Hospital, Portsmouth, United Kingdom Brit. J. Urol., 8 2 122-126, 1998 Objective: To compare the tumoricidal efficacy of meglunine y-linolenic acid (MeGLA), mitomycin C, epirubicin and water on two urothelial cell lines, and to establish t h e effect of serum protein levels derived from bladder cancer resection craters on the action of these agents. Materials and methods: The human urothelial cell lines MGHU-1 and RT112 and their drug-resistant variants were exposed to short pulses of aqueous MeGLA, rnitornycin, epirubicin and water. Both adherent and suspended cells were exposed to these agents. The MTT viable biomass assay and a clonogenic assay were used to establish tumoricidal efficacy. These experiments were then repeated to assess the effect of added serum proteins on the test results. Estimates of protein in the waste irrigation fluid from 10 patients undergoing transurethral resection of bladder tumor (TURBT) were used to select the quantity of protein used in the study to establish the clinical relevance. Results: MeGLA caused >95% reduction in the residual viable biomass of adherent cells, compared with <50% reduction with any other agent. Both epirubicin and rnitornycin were as effective as MeGLA in preventing colony formation from suspended drug-sensitive (parental) cells. However, using multidrug resistant (MDR) cell lines, only MeGLA prevented any colony formation, although counts were greatly reduced by mitomycin and epirubicin. Water was least effective as a tumoricidal agent on both adherent and suspended cells. On the latter, water was markedly inactivated by adding 5% serum. TURBT waste irrigation fluid was found frequently to contain such quantities of serous fluid contamination, as shown by albumin estimates in waste fluid from 10 consecutive patients undergoing this procedure. Conclusion: MeGLA is a n effective tumoricidal agent against both parental and MDR cell lines. Its efficacy is maintained in the presence of clinically relevant serum contamination. Editorial Comment: The authors describe the use of gamma linolenic acid intravesically to prevent tumor recurrence on the basis of its cytotoxicity to cancer cells in vitro and also possibly through its effect in reducing the number of viable cells in a clonogenic assay. Since this reagent was observed to be more tumoricidal than mitomycin, it was suggested that this agent, which apparently is not particularly toxic to normal urothelium, might be used toprevent tumor cell implantation during transurethral resection. That this agent is a precursor of pro* taglandins, which may have a role in angiogenesis and consequent tumor growth andlor recur-
1719
1720
PRINCIPLES OF ONCOLOGY, AND TUMORS OF BLADDER, PENIS AND URETHRA
rence, is particularly interesting. Theoretically, its effect may extend beyond that associated with its cytotoxicity and include an effect on blood vessels. Whether this agent could account for resistance to growth of newly implanted tumor cells or inhibition of tumor progression to grossly visible disease, or whether the reverse might occur because of a greater rate of angiogenesis might warrant examination. Agents to inhibit angiogenesis in combination with tumor cytotoxic agents might be another avenue to explore. Michael J. Droller, M.D.
LongTerm Follow-Up of an EORTC Randomized Prospective Trial Comparing Intravesical Bacille Calmette-Guerin-RNMand Mitomycin C in Superficial Bladder Cancer J. A. WITJES,A. P. M. v. D. MEIJDEN, L. COLLETTE, R. SYLVESTER, F. M. J. DEBRUYNE, A. VAN AUBEL,W. P. J. WITJESAND THE EORTC GU GROUPAND THE DUTCHSOUTH EASTCOOPERATIVE UROLOC~CAL GROUP,Departments of Urology, University Hospital, Nijmegen, Bosch Medical Center, Hertogenbosch and Sini Franciscus Ziekenhuis, Roosendaal, The Netherlands, and European Organization for Research in Cancer Therapy Data Center, Brussels, Belgium Urology, 5 2 403-410, 1998 Objectives: To determine long-term efficacy of intravesical mitomycin C (MMC) versus bacille CalmetteGuerin (BCG) in patients with superficial bladder cancer with regard to recurrences and progression. Methods: Patients with superficial bladder cancer (pTa, pT1, pTis) were treated with intravesical MMC (30 mg. weekly for 4 weeks, and thereafter monthly for 5 months) or BCG (weekly for 6 weeks). Results: Three hundred forty-four patients were eligible (171 in the BCG group, 173 in the MMC group). The median follow-up was 7.2 years. Toxicity was not significantly different between the two treatment groups. Eficacy of the two treatment policies was similar with regard to tumor recurrence. With regard to progression to invasive disease, MMC was more effective than BCG in patients without carcinoma in situ (CIS) (P = 0.006). Conclusions: We can confirm the conclusions of other studies that intravesical treatment with 30 mg of MMC remains an effective treatment option that can also be used in high-risk patients. Like others, we could not confirm that a 6-week course of BCG is more effective in the prevention of tumor progression. Of the 33 patients with tumor progression after intravesical therapy, 20 died of bladder cancer, confirming that tumor progression after intravesical therapy carries a poor prognosis. In this study the difference in toxicity between BCG and MMC was not significant. When comparing studies with MMC and BCG, differences in treatment schedule and/or patient selection should be kept in mind.
Editorial Comment: Several prospective randomized trials have provided observations of the efficacy of various intravesical agents to prevent tumor recurrence and inhibit tumor progression. This investigation examined the efficacy of BCG and mitomycin C in the long term (median followup a t least 7 years). Previous results were stated to be contradictory on the basis of short followup, patient selection, and differences in dosing and scheduling of intravesical treatment. Carcinoma in situ was an ominous factor in that progression was seen in a high proportion of these patients regardless of the intravesical agent used. Mitomycin appeared to have an advantage over BCG in patients without carcinoma in situ as progression was less frequent. However, the variability of response of carcinoma in situ to either BCG or mitomycin seems to be at variance with results reported in the United States of at least a 70% response rate to BCG. Part of the discrepancy may have to do with the pathological interpretation of disease, either initially on accession to study or subsequently in assessing response to treatment. However, in each case it is important to note a significant risk of progression, which is especially striking in patients without response to intravesical therapies. This result highlights the importance of accurate characterization of disease to begin with and accurate determination of response rates according to commonly accepted criteria for cytological and pathological observations. That 24 institutions accessioned patients to this study is important in considering these variables. The authors suggest that differences in definition of carcinoma in situ could have introduced a bias in this study, pointing to the apparent better efficacy of mitomycin than BCG with regard to tumor recurrence. That no difference could be found with regard to tumor progression underscores the need for careful assessment of patients accessioned to such studies, thorough analysis of data before accepting conclusions that may not be warranted, and clearly understood and accepted criteria to define clinical situations and the pathology of tumors being treated. Michael J. Droller, M.D.
susceptibilities to undergoing apoptosis. The aim of this study was to evaluate the effects of introduction of wild-type p53 or p2lWM1 ‘xP1( ~ 2 1on ) chemosensitivity of bladder cancer cells. Materials and Methods: The human bladder cancer cell line HT1376, which contains mutant p53 and p21 genes, was used in this study. 7 6 to cisplatin were The effects of adenoviral-mediated p53 or p21 gene transfer on sensitivity of ~ ~ 1 3cells analyzed both in vitro and in vivo. Results: The introduction of wild-type p53 gene into HT1376 markedly enhanced the sensitivity to cisplatin in vitro. Direct injection of the p53-adenoviral vector into subcutaneous HT1376 tumors established in nude mice, followed by intraperitoneally administration of cisplatin, induced massive apoptotic destruction of the tumors. In contrast, the sensitivity of HT1376 to cisplatin was not increased by the introduction of the p21 gene either in vitro or in vivo. Conclusions: These findings suggest that the combined regimen of adenoviral-mediated p53 gene transfer and cisplatin may become an efficient and powerful tool for treatment of bladder cancer.
Editorial Comment: A growing number of investigations using the principles and techniques of gene therapy to approach various urological cancers are appearing in the literature. The authors explore the possibility of combining chemotherapy with attempts to transfer p53 or p21 into urothelial cell lines as a means of restoring their capability of apoptosis (programmed cell death). A dose dependent, slight antiproliferative effect was demonstrated in vitro. Moreover, pretreatment of the cell lines with the p53 adenovirus vector appeared to enhance the sensitivity of these cells to the toxic effect of cisplatin, whereas pretreatment with the p21 adenovirus vector did not. In vivo studies, in which subcutaneous tumors were injected directly with p53 or p21 adenovirus and cisplatin was injected intraperitoneally, revealed a tumor inhibitory effect only with the p53 adenovirus vector. Gene therapy alone was not toxic to the cells in vivo. Whether this model is applicable to humans for treatment of organ confined, or possibly even of metastatic, disease is not addressed. However, a major objective in gene therapy studies remains, that is what to deliver clinically and how. Michael J. Droller, M.D.
Bladder Cancer Recurrence by Implantation of Exfoliated Cells: Is y-linolenic Acid an Effective Tumoricidal Agent?
L. 2. SOLOMON, A.M. JENNINGS,S. J. FOLEY, B.R. BIRCHAND A. J. COOPER,Departments of Urology, Southampton University Hospitals NHS Trust, Southampton and St. Mary’s Hospital, Portsmouth, United Kingdom Brit. J. Urol., 8 2 122-126, 1998 Objective: To compare the tumoricidal efficacy of meglunine y-linolenic acid (MeGLA), mitomycin C, epirubicin and water on two urothelial cell lines, and to establish t h e effect of serum protein levels derived from bladder cancer resection craters on the action of these agents. Materials and methods: The human urothelial cell lines MGHU-1 and RT112 and their drug-resistant variants were exposed to short pulses of aqueous MeGLA, rnitornycin, epirubicin and water. Both adherent and suspended cells were exposed to these agents. The MTT viable biomass assay and a clonogenic assay were used to establish tumoricidal efficacy. These experiments were then repeated to assess the effect of added serum proteins on the test results. Estimates of protein in the waste irrigation fluid from 10 patients undergoing transurethral resection of bladder tumor (TURBT) were used to select the quantity of protein used in the study to establish the clinical relevance. Results: MeGLA caused >95% reduction in the residual viable biomass of adherent cells, compared with <50% reduction with any other agent. Both epirubicin and rnitornycin were as effective as MeGLA in preventing colony formation from suspended drug-sensitive (parental) cells. However, using multidrug resistant (MDR) cell lines, only MeGLA prevented any colony formation, although counts were greatly reduced by mitomycin and epirubicin. Water was least effective as a tumoricidal agent on both adherent and suspended cells. On the latter, water was markedly inactivated by adding 5% serum. TURBT waste irrigation fluid was found frequently to contain such quantities of serous fluid contamination, as shown by albumin estimates in waste fluid from 10 consecutive patients undergoing this procedure. Conclusion: MeGLA is a n effective tumoricidal agent against both parental and MDR cell lines. Its efficacy is maintained in the presence of clinically relevant serum contamination. Editorial Comment: The authors describe the use of gamma linolenic acid intravesically to prevent tumor recurrence on the basis of its cytotoxicity to cancer cells in vitro and also possibly through its effect in reducing the number of viable cells in a clonogenic assay. Since this reagent was observed to be more tumoricidal than mitomycin, it was suggested that this agent, which apparently is not particularly toxic to normal urothelium, might be used toprevent tumor cell implantation during transurethral resection. That this agent is a precursor of pro* taglandins, which may have a role in angiogenesis and consequent tumor growth andlor recur-
1719
1720
PRINCIPLES OF ONCOLOGY, AND TUMORS OF BLADDER, PENIS AND URETHRA
rence, is particularly interesting. Theoretically, its effect may extend beyond that associated with its cytotoxicity and include an effect on blood vessels. Whether this agent could account for resistance to growth of newly implanted tumor cells or inhibition of tumor progression to grossly visible disease, or whether the reverse might occur because of a greater rate of angiogenesis might warrant examination. Agents to inhibit angiogenesis in combination with tumor cytotoxic agents might be another avenue to explore. Michael J. Droller, M.D.
LongTerm Follow-Up of an EORTC Randomized Prospective Trial Comparing Intravesical Bacille Calmette-Guerin-RNMand Mitomycin C in Superficial Bladder Cancer J. A. WITJES,A. P. M. v. D. MEIJDEN, L. COLLETTE, R. SYLVESTER, F. M. J. DEBRUYNE, A. VAN AUBEL,W. P. J. WITJESAND THE EORTC GU GROUPAND THE DUTCHSOUTH EASTCOOPERATIVE UROLOC~CAL GROUP,Departments of Urology, University Hospital, Nijmegen, Bosch Medical Center, Hertogenbosch and Sini Franciscus Ziekenhuis, Roosendaal, The Netherlands, and European Organization for Research in Cancer Therapy Data Center, Brussels, Belgium Urology, 5 2 403-410, 1998 Objectives: To determine long-term efficacy of intravesical mitomycin C (MMC) versus bacille CalmetteGuerin (BCG) in patients with superficial bladder cancer with regard to recurrences and progression. Methods: Patients with superficial bladder cancer (pTa, pT1, pTis) were treated with intravesical MMC (30 mg. weekly for 4 weeks, and thereafter monthly for 5 months) or BCG (weekly for 6 weeks). Results: Three hundred forty-four patients were eligible (171 in the BCG group, 173 in the MMC group). The median follow-up was 7.2 years. Toxicity was not significantly different between the two treatment groups. Eficacy of the two treatment policies was similar with regard to tumor recurrence. With regard to progression to invasive disease, MMC was more effective than BCG in patients without carcinoma in situ (CIS) (P = 0.006). Conclusions: We can confirm the conclusions of other studies that intravesical treatment with 30 mg of MMC remains an effective treatment option that can also be used in high-risk patients. Like others, we could not confirm that a 6-week course of BCG is more effective in the prevention of tumor progression. Of the 33 patients with tumor progression after intravesical therapy, 20 died of bladder cancer, confirming that tumor progression after intravesical therapy carries a poor prognosis. In this study the difference in toxicity between BCG and MMC was not significant. When comparing studies with MMC and BCG, differences in treatment schedule and/or patient selection should be kept in mind.
Editorial Comment: Several prospective randomized trials have provided observations of the efficacy of various intravesical agents to prevent tumor recurrence and inhibit tumor progression. This investigation examined the efficacy of BCG and mitomycin C in the long term (median followup a t least 7 years). Previous results were stated to be contradictory on the basis of short followup, patient selection, and differences in dosing and scheduling of intravesical treatment. Carcinoma in situ was an ominous factor in that progression was seen in a high proportion of these patients regardless of the intravesical agent used. Mitomycin appeared to have an advantage over BCG in patients without carcinoma in situ as progression was less frequent. However, the variability of response of carcinoma in situ to either BCG or mitomycin seems to be at variance with results reported in the United States of at least a 70% response rate to BCG. Part of the discrepancy may have to do with the pathological interpretation of disease, either initially on accession to study or subsequently in assessing response to treatment. However, in each case it is important to note a significant risk of progression, which is especially striking in patients without response to intravesical therapies. This result highlights the importance of accurate characterization of disease to begin with and accurate determination of response rates according to commonly accepted criteria for cytological and pathological observations. That 24 institutions accessioned patients to this study is important in considering these variables. The authors suggest that differences in definition of carcinoma in situ could have introduced a bias in this study, pointing to the apparent better efficacy of mitomycin than BCG with regard to tumor recurrence. That no difference could be found with regard to tumor progression underscores the need for careful assessment of patients accessioned to such studies, thorough analysis of data before accepting conclusions that may not be warranted, and clearly understood and accepted criteria to define clinical situations and the pathology of tumors being treated. Michael J. Droller, M.D.