Stage IB1 cervical cancer patients with an MRI-measured tumor size < or = 2 cm might be candidates for less-radical surgery.

OBJECTIVES: To examine the correlation between histopathology and magnetic resonance imaging (MRI) measured tumor size and define whether patients with Stage IB1 cervical cancer with an MRI-measured tumor size < or = 2 cm can be candidates for less-radical surgery. MATERIALS AND METHODS: The authors retrospectively reviewed 200 patients with Stage IB1 cervical cancer who underwent radical hysterectomy (class III) and pelvic lymphadenectomy. The largest diameter of the tumor was determined by MRI in 52 consecutive cases. RESULTS: Regarding risk factors for parametrial involvement, only tumor size and age are known before definitive surgery without conization. Multivariate analysis of these risk factors revealed that both tumor size and old age were independently associated with parametrial involvement. Eighty-eight patients had a tumor size < or = 2 cm and an age < or = 50 years, two of which (2.3%) had parametrial involvement. In 52 consecutive patients, a significant correlation between histopathology- and MRI-measured tumor size was found (r = 0.787). Twenty-three patients had an MRI-measured tumor size < or = 2 cm, none of which had parametrial involvement. CONCLUSIONS: Patients with Stage IB1 cervical cancer lesions with a tumor size < or = 2 cm measured by MRI and age < or = 50 years can be treated with less-radical surgery.

Short communication: effect of difructose anhydride III on serum immunoglobulin G concentration in newborn calves.

Difructose anhydride (DFA) III is an indigestible disaccharide that promotes paracellular absorption of calcium, magnesium, and other minerals in the intestine by acting on epithelial tight junctions. This study aimed to elucidate the effect of DFA III on serum IgG concentration. One hundred and twenty Holstein and Holstein/Japanese Black crossbred calves were randomly divided into 4 groups of 30 to receive untreated colostrum (DFA0) or colostrum containing 3, 6, or 18 g of DFA III (DFA3, DFA6, or DFA18, respectively). At 24 h after birth, both serum IgG (ranging from 16.4 to 21.2 mg/mL) and apparent efficiency of absorption (26.0 to 37.2%) showed increases with the amount of DFA III intake. By multiple regression analysis, the standardized partial regression coefficient for DFA III was 0.25, the second highest following that for the colostrum IgG concentration (0.80), indicating a positive effect of DFA III on serum IgG. A positive linear regression was found between colostrum IgG and serum IgG concentrations at 24h of age. These results indicate that IgG absorption occurred as a nonsaturable process, which might be characteristic of gradient-dependent paracellular transport. Thus, it was concluded that DFA III improves not only minerals but IgG absorption in calves.

Complications and obstetric outcomes after laser conization during pregnancy.

OBJECTIVE: The purpose of the present study was to evaluate the efficacy of diagnostic laser conization and the obstetric outcomes of patients undergoing diagnostic laser conization during pregnancy. STUDY DESIGN: The study population consisted of a consecutive series of 47 patients who presented with histologically proven carcinoma in situ microinvasive carcinoma and were treated with laser conization during pregnancy. RESULTS: Diagnostic laser conization was performed at 3-28 weeks (median, 13 weeks) of gestation. Intraoperative blood loss of > 500 ml was observed in two cases (4.3%); however, hemotransfusion was not required in either case. In the early postoperative period, two miscarriages due to preterm premature rupture of the membrane were observed. In the late postoperative period, one spontaneous abortion, three preterm deliveries, and one neonatal death were observed. All the poor obstetric outcomes were observed in the case of patients who underwent conization in the first trimester. The pathology report for the laser conization revealed that two patients (4.3%) had invasive carcinoma. Of the 47 patients, 29 (61.7%) had positive cervical margin, and 13 required postpartum surgical intervention. All patients treated were disease-free at the time of the subsequent follow-up. CONCLUSIONS: The results of the present study suggest that laser conization in pregnant patients is feasible and is comparable to cold-knife conization and loop electrosurgical excision procedures with regard to the rates of complication and obstetric outcomes. Furthermore, they indicate that the optimal time for conization is probably the second trimester.

D-dimer level as a risk factor for postoperative venous thromboembolism in Japanese women with gynecologic cancer.

BACKGROUND: The purpose of the present study was to evaluate whether early postoperative D-dimer levels and certain pre-, intra-, and postoperative parameters can be used to predict venous thromboembolism (VTE) in gynecologic cancer patients. MATERIALS AND METHODS: We prospectively evaluated 267 gynecologic cancer patients who underwent surgery at our institution. The plasma D-dimer level was measured serially before the operation and on certain postoperative days. After the operation, primary screening for VTE was undertaken by meticulous examination for clinical signs and elevation of the plasma D-dimer level. Seventy-five patients underwent multidetector row computed tomography and were subjected to further investigations. RESULTS: VTE was detected in 21 of the 75 patients. There were significant differences in the D-dimer value between VTE-positive and VTE-negative patients on postoperative days 3, 5, and 7. The optimal cut-off value for the postoperative D-dimer level was determined as 5 mug/ml on day 3. Logistic regression multivariate analysis revealed that high D-dimer values on postoperative day 3, the use of recombinant human erythropoietin (rHuEPO), and non-O blood group were independent risk factors for postoperative VTE. CONCLUSION: High plasma D-dimer level on postoperative day 3, the use of rHuEPO, and non-O blood group were independent risk factors for postoperative VTE.

Hepatocyte growth factor activator inhibitor-2 (HAI-2) is a favorable prognosis marker and inhibits cell growth through the apoptotic pathway in cervical cancer.

BACKGROUND: In light of the poor prognosis for cervical cancer, research continues into the development of innovative and efficacious treatment modalities for this disease. We investigated the role of hepatocyte growth factor activator inhibitor-2 (HAI-2) and evaluated its clinical importance in cervical cancer. PATIENTS AND METHODS: HAI-2 expression was examined in cervical cancer specimens (n=52) by immunohistochemistry. We further attempted to investigate the biological functions and inhibitory effects of HAI-2 using human papillomavirus (HPV) 16 type SiHa and HPV 18 type HeLa cervical cancer cell lines. RESULTS: There were significant correlations between HAI-2 expression and stage (P=0.017), lymph node metastasis (P=0.005) and ovarian metastasis (P=0.038). Low HAI-2 expression was a significant predictor for a poor prognosis compared with high HAI-2 expression (disease-free survival rate, P=0.016; overall survival rate, P=0.021). After transient transfection into the SiHa and HeLa cell lines, HAI-2 showed potential inhibitory effects mediated by reductions in hepsin and matriptase expression, which led to apoptosis by increasing the level of Bak and reducing the level of Bcl-2. CONCLUSIONS: The present findings indicate that low HAI-2 expression in cervical cancer may be associated with a poor prognosis. We propose that HAI-2 may represent a therapeutic target for the treatment of cervical cancer.

Phase I study of chemoradiation with nedaplatin and ifosfamide in patients with advanced squamous cell carcinoma of the uterine cervix.

Cisplatin and ifosfamide are considered among the most active drugs in both neoadjuvant and salvage treatments for patients with cervical cancer. Nedaplatin is an analog of cisplatin and it exhibits lesser nephrotoxicity, neurotoxicity, and gastrointestinal toxicity than cisplatin. This study aimed to determine the recommended dosage of nedaplatin plus ifosfamide chemoradiotherapy for advanced squamous cell carcinoma (SCC) of the uterine cervix. Beginning with a dose of 65 mg/m(2), nedaplatin (day 1) combined with ifosfamide 1 g/m(2) (days 1-5) was designed to be administered for three cycles (minimum: two cycles); its dose was gradually escalated up to 80 mg/m(2). Dose-limiting toxicity (DLT) was defined as a more than 7-day delay in the planned radiation therapy and/or planned chemotherapy (prior to the completion of two cycles) due to toxicity. Chemotherapy was not interrupted prior to the completion of two cycles in any patients. Of the 12 patients, 11 received three cycles of chemotherapy. DLT did not occur in any patient. We confirmed a clinical complete response (CR) in ten and partial response (PR) in two patients. The median follow-up period was 39 months (range: 18-57 months). Ten patients (83%) were alive and disease free, one patient was alive with disease, and only one patient died due to the disease. Nedaplatin and ifosfamide combination chemotherapy is a feasible and active chemoradiation strategy for patients with advanced SCC of the uterine cervix. With the ifosfamide dose fixed to 1 g/m(2), the recommended nedaplatin dosage was determined to be 80 mg/m(2) to be administered for three cycles.

Phase I study of weekly nedaplatin and concurrent pelvic radiotherapy as adjuvant therapy after radical surgery for cervical cancer.

Nedaplatin is an analog of cisplatin that was developed in Japan, and it exhibits less nephrotoxicity, neurotoxicity, and gastrointestinal toxicity than cisplatin. This study aimed to determine the recommended dose of weekly nedaplatin chemoradiotherapy in high-risk patients following radical surgery. Fifteen patients who required postoperative pelvic radiotherapy after radical surgery for cervical cancer were enrolled in the present study. Nedaplatin was designed to be administered for eight cycles (minimum five cycles) beginning at a weekly dose of 22.5 mg/m(2) and then escalating to 25, 27.5, and then to 30 mg/m(2). Dose-limiting toxicity was defined as a more than 7-day delay in the planned radiation therapy and/or planned chemotherapy (prior to the completion of five cycles) due to toxicity. Nedaplatin administration was interrupted prior to the completion of five cycles in one of six patients at a dose of 27.5 mg/m(2). A more than 7-day delay in the planned radiation therapy did not occur in any patient. Nedaplatin at a dose of 30 mg/m(2) was safely administered, and two of three patients could receive the planned chemotherapy consisting of eight cycles of weekly nedaplatin. Our recommended weekly nedaplatin dose was determined to be 30 mg/m(2) administered for more than five cycles and up to eight cycles if possible. Weekly administration of nedaplatin may be more tolerable and less toxic than weekly administration of cisplatin.

Versican expression in human cervical cancer.

Versican expression may enhance tumour invasion and metastasis. However, the expressions of versican in cervical cancer have seldom been characterised. The aim of this study was to investigate versican expression in human cervical cancers. We immunohistochemically investigated the expression of versican protein in 174 cervical cancers and analysed the correlation with various clinicopathological features, including patient outcome. Stromal versican expression was significantly higher in patients with lymph node metastasis (p<0.0001). Epithelial versican expression was significantly higher in patients with non-squamous cell cercinoma (p=0.0003), lymph-vascular space invasion (p=0.046), lymph node metastasis (p=0.009) and ovarian metastasis (p=0.0001). Multivariate analysis showed that high epithelial versican expression was an independent prognostic factor for disease-free survival. Versican enrichment of the tumour tissue may be associated with progression in cervical cancer. Versican expression can serve as an indicator of poor prognosis in patients with cervical cancer.

Association of CXCR4 and CCR7 chemokine receptor expression and lymph node metastasis in human cervical cancer.

BACKGROUND: The chemokine receptors CXCR4 and CCR7 have been suggested to play an important role in cancer invasion and metastasis. The expression of these receptors in human cervical cancer, however, has seldom been characterized. PATIENTS AND METHODS: We investigated the expression of CXCR4 and CCR7 in cervical cancer specimens and determined the association between their expression and the clinicopathological features observed, including patient outcome. RESULTS: CXCR4 expression was significantly higher in elderly patients (P=0.025); it was also significantly increased in patients with cancers displaying large tumor size (P=0.010), deep stromal invasion (P=0.0004), lymph-vascular space involvement (P=0.0002), or lymph node metastasis (P<0.0001). CCR7 expression was significantly higher in cases of squamous cell carcinomas (P=0.010) and in patients with cancers showing large tumor size (P<0.0001), deep stromal invasion (P<0.0001), vaginal invasion (P=0.047), lymph-vascular space involvement (P=0.012), or lymph node metastasis (P<0.0001). Logistic regression analysis revealed that deep stromal invasion (P=0.017) and CXCR4 (P=0.016) and CCR7 (P=0.022) expression were independent factors that influenced pelvic lymph node metastasis. The disease-free survival and overall survival (OS) rates of patients exhibiting both CXCR4 and CCR7 expression were significantly reduced (P<0.0001). In addition, the expression of both CXCR4 and CCR7 was an independent prognostic factor for OS (95% confidence interval=1.03-17.86; P=0.046). CONCLUSIONS: CXCR4 and CCR7 expression may be associated with lymph node metastasis; moreover, the expression of these receptors can serve as an indicator of poor prognosis in patients with cervical cancer.

Prognostic significance of stromal versican expression in human endometrial cancer.

BACKGROUND: Versican expression may enhance tumor invasion and metastasis. However, the expression of versican in human endometrial cancer has seldom been characterized. The aim of this study was to investigate versican expression in endometrial cancers. PATIENTS AND METHODS: We immunohistochemically investigated the expression of versican protein in 167 endometrial cancers and analyzed the correlation with various observed clinicopathological features, including patient outcome. RESULTS: Stromal versican expression was significantly higher in the advanced-stage (P = 0.010) and high-grade (P = 0.049) cancers, lymph node metastasis (P = 0.012), and ovarian metastasis (P = 0.024). Epithelial versican expression was significantly higher in patients with lymph node metastasis (P = 0.014) and lymph-vascular space involvement (P = 0.014). The disease-free survival (DFS) and overall survival (OS) rates of patients exhibiting high stromal versican expression were significantly lower than those of patients exhibiting low stromal versican expression (P < 0.0001). Multivariate analysis showed that high stromal versican expression was an independent prognostic factor for DFS and OS. CONCLUSIONS: Versican enrichment of the stroma may be associated with tumor progression in endometrial cancer. Stromal versican expression can serve as an indicator of poor prognosis for patients with endometrial cancer.

Heparanase expression in both normal endometrium and endometrial cancer.

The aim of this study was to investigate the relationship between heparanase expression and prognostic factors in endometrial cancer, as well as the relationship between heparanase expression during phases of the normal endometrial cycle. Immunohistochemical analysis of 166 endometrial cancers and 34 normal endometria in various phases of growth was performed. The heparanase expression in the late-proliferative phase of normal endometria was found to be significantly higher than in either the early-proliferative or the secretory phases (P= .012 and P= .044, respectively). Heparanase expression was also significantly higher in endometrial cancer patients with tumors of an advanced FIGO stage (P= .0003) and high FIGO grade (P= .004) and with cancers showing either deep myometrial invasion (P= .023), lymph node metastasis (P= .006), lymphvascular space involvement (P= .048), or positive peritoneal cytology (P= .010). The disease-free and overall survival rates of patients with intense heparanase expression were significantly lower than those of patients with absent or moderate heparanase expression (P= .004 and P= .002, respectively). Heparanase may participate in normal endometrial remodeling and can serve as an indicator of the aggressive potential and poor prognosis of endometrial cancers.

Prognostic factors in node-positive patients with stage IB-IIB cervical cancer treated by radical hysterectomy and pelvic lymphadenectomy.

OBJECTIVE: The purpose of the present study was to identify prognostic factors in surgically treated patients with stage IB-IIB cervical cancers, who also presented with positive pelvic nodes. METHOD: The patient population consisted of 68 individuals presenting with stage IB-IIB cervical cancers and with histologically proven pelvic lymph nodes. RESULT: We found no association between the type of adjuvant therapy and patient outcome. Multivariate analysis revealed that non-squamous histology was an independent prognostic factor for disease-free and overall survival rates. In squamous cell carcinomas, the bilateral nature of the positive nodes was found to be a significant factor for disease-free survival rates. In non-squamous cell carcinomas, positive nodes of more than 2 cm in size were found to be a significant factor for disease-free survival rates. CONCLUSION: Non-squamous histology was an independent prognostic factor and chemoradiotherapy did not improve the survival outcomes of the patients in this study population.

Correlation of presenting symptoms and patient characteristics with endometrial cancer prognosis in Japanese women.

OBJECTIVE: To determine whether patient characteristics and presenting symptoms could be prognostic indicators for endometrial cancer in Japanese women. METHODS: Review of the medical charts, which included presenting symptoms and other patient characteristics, of 242 women who underwent surgical treatment for FIGO stage I-IV endometrial cancer. RESULTS: FIGO stage, histologic grade, and lower abdominal pain were found to be significant independent factors for progression-free and overall survival. In contrast, abnormal uterine bleeding, comorbidities, and prior malignancy were not found to be prognostic factors. CONCLUSION: Lower abdominal pain was found to be an independent prognostic factor in endometrial cancer among Japanese women.

Loss of basement membrane heparan sulfate expression is associated with tumor progression in endometrial cancer.

Perlecan is a major heparan sulfate proteoglycan (HPSG) of the basement membrane (BM) and binds to various cytokines and growth factors via its heparan sulfate glycosaminoglycan (HS-GAG) chains. The aim of this study was to investigate BM HS-GAG expression in endometrial cancers. We investigated the expression of BM HS-GAG by immunohistochemistry in 109 endometrial cancers and analyzed correlations with various clinicopathological features. The HS-GAG expression index was significantly lower in cases of advanced stage, high-grade, deep myometrial invasion, positive peritoneal cytology, lymph vascular space invasion and lymph node metastasis. There was no association between HS-GAG expression status and patient outcome. Decreased HS-GAG expression of BM is associated with tumor progression, but is not be a useful prognostic factor in patients presenting with endometrial cancer.

Heparanase expression is an independent prognostic factor in patients with invasive cervical cancer.

BACKGROUND: Endoglycosidic heparanase degrades heparan sulfate glycosaminoglycans, and may be important in cancer invasion and metastasis, although its expression in human cervical cancer has not been characterized. MATERIALS AND METHODS: Heparanase association with clinicopathological features related to prognostic significance was examined in patients presenting with invasive cervical cancer. Gene expression of heparanase was assessed by RT-PCR in 10 normal cervix and 92 invasive cervical cancer samples. RESULTS: Heparanase mRNA expression was not detected in any of the normal cervix specimens, but was significantly higher in advanced-stage tumors (P = 0.026). In cases treated with radical hysterectomy and pelvic lymphadenectomy, heparanase mRNA expression was significantly higher in tumors exhibiting lymph-vascular space invasion (P = 0.01). A significant relationship was found between microvessel counts and heparanase mRNA expression (P = 0.035). The disease-free and overall survival rates of patients exhibiting heparanase mRNA expression were significantly lower than those of patients lacking heparanase mRNA expression (P = 0.019 and 0.017, respectively). Furthermore, multivariate analysis showed that heparanase mRNA expression was an independent prognostic factor for both disease-free and overall survival. CONCLUSIONS: These findings provide evidence that heparanase expression can serve as an indicator of aggressive potential and poor prognosis in cervical cancer. Consequently, heparanase inhibitor will be a novel candidate for therapeutic intervention in this disease.

Thrombospondin-1 and -2 messenger RNA expression in epithelial ovarian tumor.

BACKGROUND: The role of thrombospondin (TSP) in tumor progression remains controversial. The association of TSP with clinicopathological features regarding prognostic significance was examined in patients with epithelial ovarian tumor. MATERIALS AND METHODS: Gene expression of TSP-1 and TSP-2 was assessed by reverse transcriptase-polymerase chain reaction in 6 borderline and 29 malignant epithelial ovarian tumors. RESULTS: TSP-1 mRNA expression was detected in 14 out of the 29 malignant epithelial ovarian tumors (48.3%), whereas TSP-2 mRNA expression was detected in 7 malignant epithelial ovarian tumors (24.1%). In contrast, no specimen from the borderline epithelial ovarian tumors expressed TSP mRNA. TSP-1 expression was significantly higher in tumors with advanced stage, massive ascites, positive peritoneal cytology and high grade. TSP-2 expression was significantly higher in tumors with massive ascites. Patients exhibiting TSP-1 and -2 mRNA expression demonstrated a markedly poorer prognosis than those lacking TSP-1 and -2 mRNA expression. CONCLUSION: These findings provide evidence that TSP expression may be associated with an aggressive phenotype in this class of neoplasm.

Thrombospondin-1 and -2 messenger RNA expression in invasive cervical cancer: correlation with angiogenesis and prognosis.

PURPOSE: TSP association with clinicopathological features, including microvessel count, regarding prognostic significance was examined in patients presenting with invasive cervical cancer. EXPERIMENTAL DESIGN: Gene expression of TSP-1 and TSP-2 was assessed by reverse transcription-PCR in 10 normal cervix and 78 invasive cervical cancer samples. RESULTS: TSP-1 and TSP-2 mRNA expression was detected in seven (70.0%) of the normal cervical specimens. TSP-2 mRNA expression in normal cervix was significantly higher than that in cases involving cervical cancer (P = 0.032). TSP-1 mRNA expression was significantly lower in tumors characterized by advanced stage (P = 0.047). Fifty-three patients displaying stage Ib-IIb cervical cancer underwent radical hysterectomy and pelvic lymphadenectomy. Expression of TSP-1 and TSP-2 mRNA was significantly lower in tumors exhibiting parametrial invasion (P = 0.016 and P = 0.049, respectively). Microvessel counts were significantly higher when decreased TSP-1 expression was evident (P = 0.029). The microvessel count in patients lacking TSP-2 mRNA expression was higher than that observed in patients displaying TSP-2 mRNA expression, although it was not statistically significant (P = 0.062). Subjects demonstrating TSP-1 mRNA expression exhibited significantly better prognosis than those lacking TSP-1 mRNA expression (P = 0.0038). Furthermore, TSP-1 mRNA expression was an independent prognostic factor in the multivariate analysis. CONCLUSIONS: These findings provide evidence that TSP-1 expression is of value as a prognostic factor in cervical cancer. The inverse correlation between TSP expression and microvessel count also indicates that decreased TSP expression may be associated with an angiogenic phenotype in this class of neoplasm.

Thrombospondin-1 and -2 messenger RNA expression in normal and neoplastic endometrial tissues: correlation with angiogenesis and prognosis.

The role of thrombospondin (TSP) in tumor angiogenesis and progression remains controversial. The expression of TSP-1 and TSP-2 mRNAs was assessed. Furthermore, TSP association with clinicopathological features, including microvessel count, regarding prognostic significance was examined. Expression of TSP-1 and TSP-2 were assessed by reverse transcriptase-polymerase chain reaction in 18 normal endometrium and 55 endometrial cancer samples. Microvessel counts were determined by immunostaining for factor VIII-related antigen in endometrial cancer specimens. TSP-1 expression of secretory phase endometrium was markedly higher than that of proliferative phase endometrium (p=0.047). Expression of TSP-1 and TSP-2 was detected in 33 (60.0%) and 15 cases (27.3%), respectively, of 55 endometrial cancer samples. TSP-1 expression was significantly higher in tumors recovered from elderly women (p=0.009). TSP-2 expression was significantly higher in malignancies exhibiting cervical and lymph-vascular space involvement (p=0.029 and p=0.009, respectively). Although not statistically significant, microvessel counts were higher in cases displaying increased TSP-1 expression. The microvessel count in patients with TSP-2 expression was markedly higher than that observed in patients lacking TSP-2 expression (p=0.026). Subjects demonstrating TSP-2 mRNA expression displayed significantly poorer prognosis than those lacking TSP-2 mRNA expression (p=0.016). There was no association between TSP-1 mRNA expression and patient outcome. Our findings provide evidence that elevated TSP expression may be associated with an angiogenic phenotype in endometrial cancer. In addition, TSP-2 expression is a marker for poor prognosis in this disease.

Vascular endothelial growth factor-C expression and its relationship to pelvic lymph node status in invasive cervical cancer.

Vascular endothelial growth factor-C (VEGF-C) has been implicated in lymphangiogenesis, the process of new lymphatics formation. The present study investigated VEGF-C mRNA expression in invasive cervical cancer tissue. Additionally, the association of VEGF-C mRNA with clinicopathological features was examined. VEGF-C mRNA expression was assessed by reverse transcription-polymerase chain reaction using beta-action as an internal control. 75 patients presenting with invasive cervical cancer were included in the trial. VEGF-C mRNA expression was markedly higher in tumours in which pelvic lymph node metastasis was diagnosed by magnetic resonance (MR) imaging (P = 0.002). 53 patients displaying stage Ib-IIb cervical cancer underwent radical hysterectomy and pelvic lymphadenectomy. VEGF-C expression was significantly higher in tumours exhibiting deep stromal invasion, pelvic lymph node metastasis and lymph-vascular space involvement (P = 0.016, P = 0.006 and P = 0.036, respectively). Multivariate analysis revealed VEGF-C mRNA expression to be the sole independent factor influencing pelvic lymph node metastasis. Subjects demonstrating VEGF-C mRNA expression displayed significantly poorer prognoses than those lacking VEGF-C mRNA expression (P = 0.049). These findings provide evidence supporting the involvement of VEGF-C expression in the promotion of lymph node metastasis in cervical cancer. Furthermore, examination of VEGF-C expression in biopsy specimens may be beneficial in the prediction of pelvic lymph node metastasis.

Cytocidal effect and DNA damage of nedaplatin in vitro by simulating pharmacokinetic parameters.

PURPOSE: The pharmacodynamic effects of cis-diammine(glycolato)platinum (nedaplatin, 254-S) in vitro have been reported, but the dosage and exposure time in vitro have not always been based on clinical observations of the drug's actions in vivo. Regardless of the actual exposure conditions used, the effect of cell-cycle nonspecific anticancer agents such as nedaplatin is believed to depend on the area under the drug concentration-time curve (AUC). In this study, we evaluated the pharmacodynamics of nedaplatin in vitro, especially in relation to its AUC dependency, in terms of cell survival and DNA crosslinking. METHODS: BG-1 human ovarian cancer cells were treated with various concentrations of nedaplatin to simulate the pharmacokinetics of administration in a clinical setting. The BG-1 cells were exposed to nedaplatin dissolved in medium containing serum using constant concentration conditions, either high (maximum 7.69 mg/l) or low (average 1.33 mg/l). These concentrations were based on doses used in clinical studies. We then adjusted the exposure conditions in vitro to simulate the elimination of the drug from serum in vivo as follows: T1/2 alpha 1.20 h and T1/2 beta 2.70 h. The AUC values were set at 4, 8, 16, 25 and 40 mg.h/l for all exposure conditions. A colony-formation assay for the surviving fraction and an alkaline-elution assay for DNA crosslink measurement were done for the pharmacodynamic evaluation with comparison on the basis of the AUC value. RESULTS: Exposure to a low concentration for a long time was the most effective of the exposure conditions at the same AUC value. The greater the AUC value, the higher the crosslink index under all exposure conditions. This index tended to increase particularly after exposure to the low concentration. The natural logarithm of the surviving fraction (Y') was a linear function of the crosslink index regardless of the drug-exposure condition: ln(Y') = -87.2x + ln(5.79), R2 = 0.89. The threshold cytocidal effect was associated with a crosslink index of 0.02. CONCLUSION: There was a strong correlation between the cytocidal effect of nedaplatin and DNA crosslink formation. The cytocidal effect and DNA crosslinking in vitro depended on the exposure conditions used to define the AUC. Therefore, a new pharmacokinetic-pharmacodynamic model for nedaplatin must be constructed to investigate the most effective administration procedure in vivo.