Islet cell function in long-term surviving primates after segmental pancreatic allotransplantation

Islet cell function was studied in pancreatectomized primates with functioning segmental pancreatic allografts more than 100 days after transplantation. Segmental allograft recipients were immunosuppressed with total lymphoid irradiation (TL1) and cyclosporine (CSA). After 100 days, islet function was assessed, at which stage immunosuppression was terminated. Glucose, insulin, glucagon, and C-peptide response was assessed during intravenous glucose tolerance test (IVGTT) and during arginine and tolbutamide stimulation. In eight normoglycaemic primates in which immunosuppressive treatment had been stopped and with mean graft survival of 145 days, islet stimulation was associated with moderate glucose intolerance, reduced K-values, hypoinsulinaemia, and low C-peptide values. Postmortem findings in all animals intentionally killed revealed severe graft atrophy in the absence of significant rejection. Severe graft atrophy in normoglycaemic primates, together with significantly impaired graft function after segmental pancreatic transplantation compared to normal animals, suggest that transplantation of the whole pancreas may be mandatory if normal or near-normal function is to be achieved.     

Effect of combined 5-fluorouracil and radiation on murine hematopoietic tissue

The interaction of 5-fluorouracil (5-FU) and radiation in hematopoietic tissue was assessed as the survival of hematopoietic stem cells (CFUs) by means of the spleen colony assay. 5-FU was given intraperitoneally in the dose range 50-500 mg/kg body weight. In this dose range, stem cell survival decreased exponentially as a function of 5-FU dose. After 150 mg/kg of 5-FU alone (i.e. the maximum tolerated dose, MTD), the stem cell survival rapidly decreased, reaching a minimum after 1-2 days. The decrease was followed by a regeneration phase with a doubling time of about 28 h, with return to pretreatment values on day 7, and with an overshoot of survival on day 10-28. A similar regeneration was observed after 0.75 Gy radiation alone, but there was no evidence of an overshoot of stem cell number. 5-FU given 15 min before whole-body irradiation resulted in a pronounced reduction in stem cell survival due to an increase in the slope of the radiation survival curve by a factor of 2.1. After combined 5-FU and radiation, the survival rapidly decreased to a minimum at day 1, and it showed only a slight increase within the next 7 days. After this delay, the stem cells regenerated with a doubling time of about 30 h, reaching pretreatment values on day 15. The delayed stem cell regeneration was not seen following 3.5 Gy radiation alone or 225 mg/kg 5-FU alone, which resulted in the same nadir of CFUs survival as found after the combined treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

吉西他滨为基础的化疗方案治疗进展期胰腺癌的临床研究

背景与目的:进展期胰腺癌预后差.吉西他滨可以改善胰腺癌患者的生存质量,但吉西他滨联合方案疗效是否优于单药,还存在争议,国内更缺乏相关的临床研究.本研究目的是比较吉西他滨为基础的联合化疗方案与吉西他滨单药治疗进展期胰腺癌的疗效.方法:回顾性分析2000～2005年收治的40例经临床或病理确诊的进展期胰腺癌临床资料,其中吉西他滨单药组15例,吉西他滨剂量为1 000 mg/m2,每周1次,连用7周,休息2周,之后每周1次,连用3周,4周重复;吉西他滨联合治疗组25例,联合化疗方案包括吉西他滨1 000 mg/m2,每周1次,连用2周,分别联合:(1)氟尿嘧啶425～600 mg/m2,静脉滴注或持续静脉泵入,d1-5,3周重复;(2)顺铂60～75 mg/m2,分第1、2天,3周重复;(3)奥沙利铂85～130 mg/m2,d1,3周重复;(4)卡培他滨l000 mg/m2,2次/天,d1-14,3周重复.采用Kaplan-Meier生存曲线分析患者的生存期,并比较两组间的临床受益反应、中位疾病进展时间、中位生存时间和不良反应.结果:吉西他滨联合组与单药组患者的临床受益反应均得到改善(56.0% vs.46.7%),但疾病控制率、中位生存时间、临床受益反应在两组之间差异无统计学意义(P＞0.05),不良反应的发生率也相似(P＞0.05).对Ⅲ～Ⅳ期患者进行分层分析,发现吉西他滨联合组疾病控制率高于单药组(75.0% vs.45.5%),但无统计学意义(P=0.13).结论:吉西他滨联合方案与单药治疗进展期胰腺癌相比,疗效、临床受益反应、中位生存时间两组相似.     

A phase I study of combination chemotherapy with gemcitabine and oral S-1 for advanced pancreatic cancer

OBJECTIVE: The aim of this study was to determine the maximum-tolerated dose and dose-limiting toxicity (DLT) of combination therapy with gemcitabine and S-1 in patients with advanced pancreatic cancer. METHODS: Chemotherapy-naive patients with histologically or cytologically proven unresectable or metastatic pancreatic cancer were enrolled. The patients received gemcitabine intravenously over 30 min on days 1 and 8 and S-1 orally twice daily from days 1 to 14. Cycles were repeated every 21 days until disease progression. Patients were scheduled to receive gemcitabine (mg/m(2)/week) and S-1 (mg/m(2)/day) at four dose levels: 800/60 (level 1), 1,000/60 (level 2), 1,000/70 (level 3) and 1,000/80 (level 4). RESULTS: Eighteen patients were enrolled in this study. The maximum-tolerated dose was not reached even at the highest dose level (level 4) because only 2 of the 6 patients at this level experienced DLT. The DLTs were neutropenia and rash. Six (33%) of the 18 patients achieved a partial response and median overall survival time was 7.6 months. CONCLUSIONS: Combination chemotherapy with gemcitabine and S-1 was well tolerated and showed good antitumor activity in the treatment of pancreatic cancer. We recommend a gemcitabine dose of 1,000 mg/m(2)/week and an S-1 dose of 80 mg/m(2)/day in further studies with this schedule.     

Phase I/II study of combination chemotherapy with gemcitabine and UFT for advanced pancreatic cancer in a multi-center trial

The aim of this phase I/II study was to evaluate the tolerability and efficacy of combination chemotherapy with gemcitabine (GEM) and UFT for advanced pancreatic cancer. In phase I study UFT was given orally every day for 14 days and GEM was infused on day 1 and 8 at three dose levels (800, 900, 1,000 mg/m(2)/week) every 21 days. GEM 1,000 mg/m(2) and UFT 400 mg/m(2) did not reach the maximum tolerated dose. We decided that the recommended dose (RD) was GEM 1,000 mg/m(2)and UFT 400 mg/m(2). In phase II study 27 patients were enrolled and received GEM and UFT at RD. The tumor response rate was 17.6%, and the median survival was 221 days, which was very similar to that of GEM monotherapy. Due to adverse events, especially liver dysfunction, protocol therapy was discontinued in 12 patients. This study could not revealed the superiority of the GEM monotherapy.     

The effect of ionizing radiation on the primate pancreas: An endocrine and morphologic study

In this study we evaluated the endocrine, biochemical, and haematological derangements as well as pancreatic and histological changes of the bone-marrow in the primate following external fractionated subtotal marrow irradiation without bonemarrow reconstitution. The irradiation was administered in preparation for pancreatic transplantation. Two groups of animals (ten in each group) received 800 rad (8 Gy) and 1,000 rad (10 Gy) respectively over 4 to 5 weeks. A maximum of 200 rads (2 Gy) were administered weekly as photons from a 6 MV linear accelerator. During irradiation the animals remained normoglycaemic in the presence of transiently elevated liver enzymes and serum amylase values, which returned to normal on completion of the irradiation. Insulin release was significantly reduced in both groups during irradiation and was associated with minimally decreased K-values in the presence of mild glucose intolerance. Pancreatic light morphologic changes included structural changes of both exocrine and endocrine elements and included necrosis of the islet cells and acinar tissue. Islet histology demonstrated striking cytocavitary network changes of alpha and beta cells, including degranulation, vacuolization, mitochondrial destruction, and an increase in lysosomes. A hypoplastic bonemarrow ranging from moderate to severe was observed in all irradiated recipients. Near total fractionated body irradiation in the primate is therefore associated with elevated liver enzymes, pancytopenia, transient hyperamylasaemia, hypoinsulinaemia, a varying degree of pancreatitis, and bonemarrow hypoplasia.     

Effect of intraperitoneal chemotherapy on experimental peritoneal dissemination of gastric cancer

In vitro chemosensitivity test using a collagen-gel method was done on 165 primary gastric cancers. All of 5-FU, CBDCA, CDDP and docetaxel showed a high sensitivity. The effects of per oral (po) administration of TS-1, a combination of po TS-1 and intraperitoneal (ip) administration of CDDP, ip 5-FU and ip docetaxel, were evaluated in athymic mice bearing peritoneal dissemination of a gastric cancer cell line (MKN-45-P that shows a high rate of metastasis to the peritoneal cavity of nude mice). Nude mice were inoculated by ip with 10(7) MKN-45-P cells. No survival benefit was obtained after po administration of TS-1 (12 mg/kg) alone or ip CDDP alone. However, a combination of po TS-1 (8 mg/kg x 10 days, from day 3) and ip CDDP (3.5 mg/kg, day 6 and 13) showed a significant survival improvement than that of po TS-1 or ip CDDP treatment alone. ip administration of 30 mg/kg (3 times/week x 3 weeks) or 15 mg/kg (6 times/week x 3 weeks) of 5-FU significantly improved the survival of mice bearing MKN-45-P. 5-FU concentration of ascites after ip administration of 30 mg/kg of 5-FU was 600-fold higher than po administration of 12 mg/kg of TS-1 at peak level. ip injections of docetaxel of 8 mg/kg, and 2 mg/kg improved the survival of 4 and 1 mice, respectively, and they were tumor-free on day 90. Survival of mice treated with ip injection of CBDCA (100 mg/kg, on day 3, or 50 mg/ kg on day 3 and 10) was significantly better than the control group. These results suggest the potential of po TS-1 + ip CDDP, ip 5-FU, ip docetaxel and ip CBDCA administration for the treatment of peritoneal dissemination of gastric cancer.     

Tumor necrosis factor-alpha (TNF alpha) enhances cisplatin cytotoxicity to ovarian carcinoma xenografts

Antitumor effect was compared between administration schedule of once a day dosing of cisplatin (DDP) for 2 consecutive days (q40d) with or without TNF alpha. In two controls, TNF alpha or dilutor alone was administered. Against the ovarian carcinoma 2008 cells, DDP given at dose level of daily x 2 (3.5 mg/kg/day q40d) combined with TNF alpha (50 mu g/kg/day) schedule showed 6.08-fold tumor growth delay (TGD) (17.10+/-1.65; P<0.01), produced 3.17-fold greater cell kill [ratio of tumor volume of treated and control groups (T:C)=0.148; P<0.01] and resulted in longer survival [median survival (MS)=166; P<0.01] than DDP alone. These are superior to even high dose DDP (7.0 mg/kg/day x 2d) without TNF alpha administration schedule showing TGD=11.38 days T:C=0.271 and MS=97 days. High dose DDP (7.0 mg/kg/day q40d) with TNF alpha showed further DDP antitumor potency (TGD=29.74+/-2.08, P<0.01), however, this schedule showed only 2.56-fold TGD extension and no improvement was found in survival because of its severe toxicity. TNF alpha did not alter DDP induced systemic toxicity. These data indicate that optimal antitumor activity, tolerance and survival improvement occured on a schedule of low dose DDP combined with TNF alpha, and this has prompted the clinical evaluation of this administration schedule.     

Combination therapy using gemcitabine and radioimmunotherapy in nude mice with small peritoneal metastases of colonic origin

INTRODUCTION: Gemcitabine has been shown to exert a radiosensitizing effect in various epithelial cancers. The aim of the present studies was to investigate whether the efficacy of radioimmunotherapy (RIT) using the (131)I-labeled anti-CEA monoclonal antibody (MAb) MN-14 could be enhanced by coadministration of gemcitabine in nude mice with small (1-3 mm) peritoneal metastases of colonic origin. MATERIALS AND METHODS: Firstly, the maximum tolerated dose (MTD) of gemcitabine was determined, when administered intraperitoneally at two different dosing schedules (0.11-3.0 mg/mouse/administration on days 0, 3, 6, and 9, or 0.022-0.60 mg/mouse/administration on days 0, 1, 2, 3, and 4). In two separate therapy studies in which these two administration regimens were applied, the efficacy of gemcitabine monotherapy was compared to that of RIT alone (125 muCi (131)I-MN-14/mouse) or RIT combined with gemcitabine. RESULTS: When administered every 3rd day for a total of 4 administrations, or daily for 5 consecutive days, the gemcitabine was considered safe at 0.33 mg/mouse/administration and 0.066 mg/mouse/administration, respectively. In the first therapy study, median survival of the control mice was 39 days. Gemcitabine monotherapy at 0.11 mg or 0.33 mg/mouse/administration every 3rd day (total, 4 administrations) resulted in a median survival of 52 and 57 days, respectively (p = 0.0003, compared to controls). RIT alone resulted in a median survival of 66 days (p < 0.0001, compared to controls). The combination of RIT and gemcitabine coadministration resulted in a median survival of 73 and 94 days, respectively (p = 0.12, for trend). In the second therapy study, median survival of the control mice was 48 days, which was similar to the median survival of the mice treated with daily administrations of gemcitabine monotherapy at 0.022 mg/mouse/administration on 5 consecutive days (49 days; p = 0.17). RIT alone resulted in a significantly improved median survival of 66 days (p= = 0.0010, compared to controls). Combination therapy using RIT and gemcitabine resulted in a median survival of 64 days, which did not differ significantly from the survival of the mice treated with RIT alone (p = 0.43). CONCLUSIONS: At the dose regimens employed, gemcitabine did not enhance the efficacy of RIT of experimental small-volume peritoneal carcinomatosis of colonic origin.     

Phase I trial of radiation dose escalation with concurrent weekly full-dose gemcitabine in patients with advanced pancreatic cancer.

PURPOSE: The primary objective of this phase I trial was to determine the maximum-tolerated dose of radiation that could be delivered to the primary tumor concurrent with full-dose gemcitabine in patients with advanced pancreatic cancer. PATIENTS AND METHODS: Thirty seven patients with unresectable (n = 34) or incompletely resected pancreatic cancer (n = 3) were treated. Gemcitabine was administered as a 30-minute intravenous infusion at a dose of 1,000 mg/m(2) on days 1, 8, and 15 of a 28-day cycle. Radiation therapy was initiated on day 1 and directed at the primary tumor alone, without prophylactic nodal coverage. The starting radiation dose was 24 Gy in 1.6-Gy fractions. Escalation was achieved by increasing the fraction size in increments of 0.2 Gy, keeping the duration of radiation constant at 3 weeks. A second cycle of gemcitabine alone was intended after a 1-week rest. RESULTS: Two of six assessable patients experienced dose-limiting toxicity at the final planned dose level of the trial (42 Gy in 2.8-Gy fractions), one with grade 4 vomiting and one with gastric/duodenal ulceration. Two additional patients at this dose level experienced late gastrointestinal toxicity that required surgical management. CONCLUSION: The final dose investigated (42 Gy) is not recommended for further study considering the occurrence of both acute and late toxicity. However, a phase II trial of this novel gemcitabine-based chemoradiotherapy approach, at a radiation dose of 36 Gy in 2.4-Gy fractions, is recommended on the basis of tolerance, patterns of failure, and survival data.     

Gemcitabine combined with docetaxel for the treatment of unresectable pancreatic carcinoma

Purpose. To assess the efficacy and toxicity of combination therapy with gemcitabine and docetaxel in patients with unresectable pancreatic carcinoma. Patients and Methods. Thirty-four patients with unresectable stage III, IVA, and IVB pancreatic carcinoma were eligible for this study. The first 18 patients received gemcitabine 800 mg/m² intravenously (IV) on days 1, 8, and 15 and docetaxel 75 mg/m² IV on day 1, repeated every 28 days. Due to a high incidence of myelosuppression in this first group, the treatment schedule was modified in the remaining patients to gemcitabine 1,000 mg/m² IV and docetaxel 40 mg/m² IV on days 1 and 8 of a 21-day schedule. The primary study endpoints were objective response rate and duration of survival. Results. Ten of 33 evaluable patients achieved a partial response, for an overall response rate of 30.3% (95% CI, 16.21%-48.87%). Partial responses noted in the pancreas and a variety of metastatic sites were maintained for 4 to 12 months (median 6 months). Twelve additional patients (36%) experienced stable disease. The median time to progression was 6 months, and median survival was 10.5 months. The toxicity profile of the modified gemcitabine/docetaxel schedule was more favorable than that associated with the initial regimen, particularly with respect to hematologic toxicity. Conclusion. The response and survival data reported here for combination therapy with gemcitabine and docetaxel are encouraging given the poor prognosis associated with unresectable pancreatic cancer. These data suggest that gemcitabine plus docetaxel may be more effective than either agent alone in the treatment of pancreatic cancer and warrants further study.     

Survival efficacy of adjuvant cytosine-analogue CS-682 in a fluorescent orthotopic model of human pancreatic cancer

Adjuvant treatment with the cytosine analogue 1-(2-C-cyano-2-deoxy-beta-D-arabino-pentofuranosyl)-N(4)-palmitoylcytosine (CS-682) results in a highly significant increase in survival in the aggressive orthotopic MIA-PaCa-2 human pancreatic cancer mouse model. Seven days after implantation, mice were randomized into eight groups, depending on whether they were to be treated by tumor resection, 5 weeks of CS-682 chemotherapy at 40-60 mg/kg once daily, or both. Throughout the course of treatment, noninvasive optical whole-body imaging based on brilliant red fluorescent protein expression of the tumor permitted visualization and quantification of primary, metastatic, and recurrent disease. Total tumor burden negatively correlated with survival. Untreated mice died of disseminated disease with a median survival of 26 days. Surgical resection alone conferred a small but significant survival advantage (median survival, 28 days, P = 0.03). Primary CS-682 treatment at all doses also significantly prolonged survival compared with untreated animals (P < 0.05) and was more effective than surgery alone at doses of 50 and 60 mg/kg (median survival, 34 days, P = 0.045, and 38.5 days, P = 0.03, respectively). Maximal survival (median, 48 days, with 30% of animals surviving longer than 60 days) was achieved by adjuvant CS-682 (50 mg/kg), given after surgical resection of the primary pancreatic tumor (P = 0.004 compared with surgery alone). The results demonstrate that adjuvant oral administration of CS-682 for pancreatic cancer is highly effective with acceptable toxicity, suggesting its potential for cure of this disease in appropriate combinations.     

Biochemical modulation of combined radiation and 5-fluorouracil treatment of murine tumors by d,l-leucovorin

Experiments were designed to establish whether the response of the Lewis lung tumor (LLca) to combined 5-Fluorouracil (5-FU) and radiation could be enhanced by the addition of the reduced folate leucovorin (LV) to the treatment protocol. Twenty-four hr after the tumors received a single dose of from 2.0 to 8.0 Gy of X-rays, the tumor-bearing animals were treated with a 5 day schedule of 10 mg/kg LV + 30 mg/kg 5-flourouracil (q 24 hr) in which LV preceded the 5-FU by 60 minutes. Under these time/dose configurations, no evidence of treatment-limiting gastrointestinal or hematopoietic toxicity was observed with the LV + 5-FU treatment. Following radiotherapy alone, tumor growth delays (TGDs) ranging from 1 to 6.5 days were observed with X-ray doses of from 2.0 to 8.0 Gy, respectively. When the radiotherapy was followed by the administration of 5-FU (q24 hr x 5) alone, a modest increase in the tumor response was observed; TGD increased from 1.0 to 2.0 days with 2.0 Gy and from 6.5 to 8.5 days with 8.0 Gy of X-rays. The addition of LV to the 5-FU schedule, however, resulted in a significant enhancement of the response of the tumor to the combined radiation + 5-FU treatment. TGDs increased from 1.0 to 8.0 days with a radiation dose of 2.0 Gy and from 6.5 to 34.5 days with a dose of 8.0 Gy. When administered as single agents, 5-FU and 2.0 Gy resulted in only a modest response by the LLca tumor (TGDs = 1.0 day), while LV had no effect on tumor growth. These observations, therefore, suggest that biochemical modulation of 5-FU by LV can be realized in vivo and that this biochemical modulation may be valuable in more conventional clinical schedules using combined radiation and 5-FU treatment.     

5-Fluorouracil infusions and fractionated doses of radiation: studies with a murine squamous cell carcinoma

The present investigation describes the effects on a murine squamous cell tumor of combined treatment using radiation and 5-Fluorouracil (5FU), with emphasis on 5FU infusions. The tumor, SCC VII/To, was grown intramuscularly in the hind legs of C3H mice. Radiation was given locally with 100 kVp X rays either alone or in combination with 5FU by i.p. bolus injections or 4-14 day infusions using subcutaneously implanted mini-osmotic pumps. Studies with radiation alone indicated regrowth delay increased with total dose. This increase was less for fractionated than single doses. The effects of 5FU alone were compared using i.p. injections or 4, 7 or 14 day infusions. Tumor response to single i.p. bolus injections or 4 day infusions were not significantly different. Up to total drug doses of 200 mg/kg, 14 day infusions were least effective on regrowth delay, 4 day infusions were intermediate and 7 day infusions were most effective. Above total drug doses of 200 mg/kg, effects of 14 day infusions on regrowth delay increased rapidly. The LD50 for single i.p. bolus injections and 7 day infusions were similar, 230 and a total drug dose of 270 mg/kg, respectively. When a 7 day infusion of 5FU (133 mg/kg) was combined with increasing total radiation doses (1 or 5 fractions), the increase in regrowth delay was additive. Combining a fractionated dose of 5 Gy per day for 5 days (5/5 Gy) with increasing total drug doses of 5FU (single i.p. bolus injections or 4, 7 or 14 day infusions) resulted in regrowth delays that were dependent on the total dose of 5FU. Administering a 133 mg/kg dose of 5FU (via a single i.p. bolus injection or 7 day infusion) starting 2 days before, during, or immediately after 5/5 Gy gave the same regrowth delay, indicating no effect of drug sequencing. In conclusion, the above data indicate that (a) 5FU infusions (greater than 4 days) are more effective than 5FU injections on regrowth delay and (b) combinations of 5FU and radiation, produce an additive tumor response, which occurs independent of mode, schedule, and time of 5FU administration, and is dependent on 5FU total dose.     

Phase I study of MST-16

Phase I study with a new oral anticancer agents. MST-16 (Sobuzoxane), was conducted by 3 administration schedules: single, 5 consecutive days and 10-15 consecutive days. No toxicity was observed in the single administration at doses escalated up to 1,500 mg/m2. Dose-dependent leukopenia was observed from 560 mg/m2/day in consecutive 5 day administration, and median days to the nadir and recovery were about 2 and 1 week, respectively. GI-disorders were also observed sporadically from 800 mg/m2/day. One patient with Hodgkin's disease receiving 1,000 mg/m2/day achieved complete response. Consecutive administration for 10-15 days was carried out at a dose of 800 mg/m2/day. Six out of 7 evaluable patients demonstrated leukopenia, and all 2 patients treated for 15 days experienced leukopenia with a nadir corresponding to grade 3. Median days to nadir and recovery were both about 2 weeks. Doses recommended for phase II study were considered to be 1,600 mg/body/day for 5 days and 1,200 mg/body/day for 10-14 days.     

Combined chemo-radiotherapy for stage IV undifferentiated nasopharyngeal carcinoma

Undifferentiated nasopharyngeal carcinoma is a chemosensitive lesion, but its role in the management of local advanced disease is under investigation. Twenty-seven untreated stage IV undifferentiated nasopharyngeal carcinoma patients were treated with radiotherapy (median dose, 66.6 Gy, 1.8 Gy/day) and concomitant cisplatin (100 mg/m2 days 1, 22 and 43). After 4 weeks, patients received, every 4 weeks, 3 cycles with cisplatin (80 mg/m2 day 1) + 5-fluorouracil (1,000 mg/m2/day continuous infusion for 96 h). After radiotherapy, we observed 74% complete responses and 26% partial responses; after adjuvant chemotherapy 96% had a complete and 4% a partial response. After a median follow-up of 36 months, 81% of the patients were alive (70% with no evidence of disease). Four-year overall and disease-free survival was 70% and 60%, respectively. Concomitant chemotherapy plus radiotherapy was well tolerated, whereas adjuvant chemotherapy was more toxic. Long-term results were significantly better than those observed with radiotherapy alone.     

Impact of overall treatment time on local control of anal cancer treated with radiochemotherapy

Between 1987 and 2000, 111 patients with epidermoid anal cancer (T1-T4 Nx M0) were assigned to primary simultaneous radiochemotherapy (RCT) with a radiation dose of 45 Gy, performed either as a split course with 2-Gy single fractions (schedule A, 1987-1996, n = 65 patients) or continuously with fractions of 1.8 Gy (schedule B, 1996-2000; n = 38 patients). The chemotherapy consisted of continuous infusions of 5-fluorouracil (5-FU; 800/1,000 mg/m(2)/day, on 4/5 consecutive days, during weeks 1 and 5) together with one (schedule A) or two (schedule B) short infusions of mitomycin C (10 mg/m(2)) during the first course of 5-FU. Associations between clinical outcome and various prognostic factors were assessed in 103 patients who completed these schedules. For both patient groups combined, 5-year local control rate was 67% and 5-year survival rate 71%. Advanced tumor stage, size, and nodal status significantly decreased the 5-year local control rate as well as the overall treatment time (OTT) >41 days (58% for OTT >41 days vs. 79% for OTT < or =41 days; p = 0.04). However, we did not find a correlation with the prescribed radiotherapy schedule (A or B). In conclusion, in patients with anal carcinomas treated with RCT with a radiation dose of 45 Gy, the predominant determinant of local control is the resulting OTT and not the administration schedule (split course or continuous radiotherapy).     

Matrix metalloproteinase inhibitor, marimastat, decreases peritoneal spread of gastric carcinoma in nude mice.

Marimastat, a matrix metalloproteinese inhibitor, was examined for the ability to prevent peritoneal dissemination of a human gastric cancer xenograft, TMK-1. Even with novel approaches such as molecular targeting of cancer chemotherapy, peritoneal dissemination of gastric cancer has little sensitivity to anticancer drugs, and it is impossible to inhibit its growth completely. Intraperitoneal injection of TMK-1 into nude mice at 5 x 10( 5) cells / body resulted in carcinomatous peritonitis that mimicked clinical cases. Continuous administration of marimastat (18 mg / kg / day) from 24 h after the tumor inoculation successfully inhibited the growth of peritoneal dissemination nodules. Combined administration of marimastat (18 mg / kg / day) and mitomycin C (MMC, 2 mg / kg) showed synergistic inhibition of growth of peritoneal dissemination, being superior to MMC alone (2 mg / kg). Although marimastat alone could not increase survival time with statistical significance, combined administration of marimastat and MMC had a survival benefit with statistical significance. The combination of marimastat and MMC increased the preventive effect on peritoneal dissemination. Marimastat seems to be a candidate for the prevention of peritoneal spread of gastric carcinoma.     

Enhancement of murine bone marrow ablation by combining whole body hyperthermia with total body irradiation and cyclophosphamide

Bone marrow ablation using combined whole body hyperthermia (WBH), total body irradiation (TBI), and cyclophosphamide (Cy) was investigated in C3H f/Sed mice to demonstrate cytotoxic synergism between the three modalities. TBI was given on day 0. WBH treatment was for 1 hr at 41.8 degrees C, given in daily sessions for 1, 2 or 3 modalities. TBI was given on day 0. WBH treatment was for 1 hr at 41.8 degrees C, given in daily sessions for 1, 2 or 3 consecutive days following TBI. Total cyclophosphamide doses were 160 and 240 mg/kg given in 2 daily injections on days 1 and 2 following TBI. Polymorphonuclear leukocyte and lymphocyte numbers were determined by differential cell counts. The total peripheral blood cell counts were also determined. WBH alone, given in daily sessions for 3 days, did not reduce the total peripheral blood cell counts. However, when WBH was added to TBI (6.3 Gy) peripheral blood cellularity was reduced on day 2, but no significant heat/radiosensitization was evident after day 2. WBH (3 daily sessions) significantly reduced the peripheral blood cellularity and resulted in bone marrow ablation when it was combined with TBI and Cy. CY (160-240 mg/kg) combined with TBI (5.4 Gy) resulted in bone marrow ablation and subsequent death in 14-22% of mice treated; 60-100% of mice died from bone marrow ablation when WBH was added to TBI (5.4 Gy) and Cy (160-240 mg/kg). Femoral and vertebral tissue sections showed total loss of progenitor cells when WBH, TBI (5.4 Gy), and Cy (240 mg/kg) were combined whereas lessor treatment was associated with histologically verified reconstitution of progenitor cells inside the marrow cavities. These studies indicate that bone marrow ablation can be achieved when using WBH in combination with lower doses of TBI and Cy.     

Lung damage following bone marrow transplantation: II. The contribution of cyclophosphamide

The effect of high-dose cyclophosphamide (Cy), either alone or in combination with irradiation, upon the development of interstitial pneumonitis (IP) after bone marrow transplantation (BMT) was investigated in a Brown Norway rat model. The parameters that were examined included ventilation rate, mortality, and histopathology. No damage to the lungs was observed in rats given Cy alone in supralethal dosages plus BMT, and mortality resulted from severe aplasia of hemopoietic and lymphoid tissues with multifocal hemorrhages, secondary infections, and sepsis. Two separate periods of mortality were observed within the first 180 days following whole thorax irradiation with a high dose rate (HDR; 0.8 Gy/min) or a low dose rate (LDR; 0.05 Gy/min). The addition of Cy prior to irradiation resulted in an increased mortality in the first period (before day 100) in all experimental groups. The influence of Cy on mortality at 180 days however, was different for the HDR and LDR experiments. The LD50-180 after HDR irradiation, dose range 8 to 18 Gy, was not significantly altered by the addition of Cy (100 mg/kg) 1 day prior to irradiation, whereas Cy (100 mg/kg) 1 day prior to LDR irradiation, dose range: 16 to 24 Gy, caused an enhancement of radiation damage with a decrease of the LD50-180 by 1.33 Gy. The dose modification factor (DMF) was 1.07. This enhancement was no longer significant after splitting up the dose of Cy in two dosages of 50 mg/kg given on 2 consecutive days prior to irradiation with a LDR. The extrapolation of the data in this rat model to available dose-response curves on IP after BMT and radiation pneumonitis in humans, implied that non-infectious IP is a radiation pneumonitis that is only slightly enhanced by Cy.