Topoisomerase-I activity and response to second-line chemotherapy consisting of camptothecin-11 and cisplatin in patients with ovarian cancer

Combination of irinotecan and platinum for platinum-resistant or refractory recurrent ovarian cancers: A preliminary case series

Non-platinum single agents are usually used for patients with platinum-resistant recurrent ovarian cancers (ROC). However, the efficacy of these drugs is limited. The aim of the present study was to evaluate the efficacy and adverse events (AE) of combination therapy with irinotecan and platinum (CPT-Pt) for ROC. A total of 28 platinum-resistant or refractory patients with ROC treated with CPT-Pt at the National Defense Medical College Hospital institution between 2002 and 2012 were identified. All patients received taxane and carboplatin (TC) as a first-line treatment and relapsed within 6 months after completion of TC, or progressed during TC therapy. The median age was 59 years (range, 16-78), and median number of CPT-Pt therapy cycles was 5.5 (range, 2-16). The overall response rate was 14%, with a complete response (CR) in 2 patients and partial response (PR) in 2 patients. Stable disease (SD) for >3 months was observed in 15 patients (54%), resulting in a clinical benefit rate (CBR = CR + PR + SD) of 68%. The median progression-free survival and overall survival were 8 and 15 months, respectively. Fifteen cases (68%) developed grade 3/4 hematological AE and 3 cases (11%) developed non-hematological grade 3/4 AE, which were resolved by conservative management or dose reduction. Platinum re-treatment with irinotecan for platinum refractory or resistant ROC may be a candidate in such clinical settings.

Association of a newly identified variant of DNA polymerase beta (polβΔ63-123, 208-304) with the risk factor of ovarian carcinoma in India

BACKGROUND

DNA polymerase is a single-copy gene that is considered to be part of the DNA repair machinery in mammalian cells. The encoded enzyme is a key to the base excision repair (BER) pathway. It is evident that pol beta has mutations in various cancer samples, but little is known about ovarian cancer.

AIM

Identification of any variant form of polβ cDNA in ovarian carcinoma and determination of association between the polymorphism and ovarian cancer risk in Indian patients. We used 152 samples to isolate and perform RT-PCR and sequencing.

RESULTS

A variant of polymerase beta (deletion of exon 4-6 and 11-13, comprising of amino acid 63-123, and 208-304) is detected in heterozygous condition. The product size of this variant is 532 bp while wild type pol beta is 1 kb. Our study of association between the variant and the endometrioid type shows that it is a statistically significant factor for ovarian cancer [OR=31.9 (4.12-246.25) with p<0.001]. The association between variant and stage IV patients further indicated risk (χ2 value of 29.7, and OR value 6.77 with 95% CI values 3.3-13.86). The correlation study also confirms the association data (Pearson correlation values for variant/stage IV and variant/endometrioid of 0.44 and 0.39).

CONCLUSION

Individuals from this part of India with this type of variant may be at risk of stage IV, endometrioid type ovarian carcinoma.

Genetic diagnosis for chemosensitivity with drug-resistance genes in epithelial ovarian cancer

We conducted the present study to investigate whether and how chemosensitivity can be determined by means of genetic diagnosis using drug-resistance genes in patients with epithelial ovarian cancer. A total of 75 patients who had epithelial ovarian cancer with measurable lesions were entered into this study. Thirty-three patients received first-line chemotherapy, consisting of paclitaxel and carboplatin (TJ). Forty-two patients received second-line chemotherapy, 22 received EP therapy consisting of etoposide and cisplatin (CDDP), and 20 received irinotecan (CPT-11) and CDDP (CPT-11/CDDP) therapy. Tumor samples were obtained before chemotherapy. MessengerRNA expressions of the multidrug-resistance (MDR)-1 gene, MDR-associated protein-1 (MRP-1), topoisomerase (topo) I, and topo IIalpha were measured by real-time reverse transcription-polymerase chain reaction. The cutoff values of each gene were determined by the receiver operating characteristic curve. MDR-1 expression was significantly higher in patients who did not respond to TJ therapy. The expression of topo IIalpha was significantly higher in patients who did respond to EP therapy. The expression of topo I was significantly higher in patients who did respond to CPT-11/CDDP. MRP-1 expression did not differ between responders and nonresponders in all regimens. The cutoff value was 80 for MDR-1, 90 for topo IIalpha, and 200 for topo I. Next, to evaluate genetic diagnosis, 31 patients were newly added. The accuracy of this genetic diagnosis for chemosensitivity was 85.7% for TJ, 77.8% for EP, and 100.0% for CPT-11/CDDP therapy. The present study suggests that genetic diagnosis may be useful to determine chemosensitivity in patients with epithelial ovarian cancer.

A phase I study and pharmacologic evaluation of irinotecan and carboplatin for patients with advanced ovarian carcinoma who previously received platinum-containing chemotherapy

BACKGROUND

The objectives of the current study were to determine the maximum tolerated dose (MTD) of irinotecan and carboplatin in combination, to evaluate the efficacy and toxicity of the combination in patients with advanced ovarian carcinoma who previously received platinum-containing chemotherapy, and to examine the pharmacokinetics and pharmacodynamics of both drugs by using the Chatelut formula.

METHODS

Patients with advanced ovarian carcinoma who previously received platinum-containing chemotherapy were treated with a combination of irinotecan and carboplatin. Carboplatin was administered as a 60-minute intravenous infusion on Day 1 and was followed by irinotecan, which was administered as a 90-minute intravenous infusion on Days 1, 8, and 15. Six dose levels of irinotecan (in mg/m(2))/carboplatin (mg . mL/min) were planned: 50 mg/m(2)/4 mg . mL/minute, 60 mg/m(2)/4 mg . mL/minute, 50 mg/m(2)/5 mg . mL/minute, 60 mg/m(2)/5 mg . mL/minute, 50 mg/m(2)/6 mg . mL/minute, and 60 mg/m(2)/6 mg . mL/minute. The carboplatin dosage was calculated by using the Chatelut formula. Treatment was repeated at 28-day intervals.

RESULTS

In total, 19 patients in cohorts of 3 to 5 patients received irinotecan and carboplatin at 5 dose levels. The dose-limiting toxicities were Grade 4 neutropenia and Grade 4 thrombocytopenia. The MTD of the irinotecan/carboplatin combination was 60 mg/m(2)/5 . mg mL/minute. Partial responses were observed at higher dose levels. Pharmacologic studies demonstrated that administration of the dosage estimated with the Chatelut formula instead of the Chatelut formula with adjustment for serum creatinine resulted in a slightly excessive dose of carboplatin.

CONCLUSIONS

The recommended dose for the Phase II study was irinotecan 60 mg/m(2) on Days 1, 8, and 15 with carboplatin 5 mg/mL . minute on Day 1 repeated every 4 weeks.

Topoisomerase-I, thymidylate synthase primary tumour expression and clinical efficacy of 5-FU/CPT-11 chemotherapy in advanced colorectal cancer patients

While several studies have reported that thymidylate synthase (TS) tumour expression can be a reliable predictive marker of clinical response to 5-Fluorouracil (5-FU) for advanced colorectal cancer patients, only a few studies that searched for predictive factors of irinotecan (CPT-11) clinical response are available. The aim of the present study has been to verify the predictive value of immunohistochemical topoisomerase-I (Topo-I) and TS primary tumour expression in a consecutive series of 62 advanced colorectal cancer patients that received a first line 5-FU/CPT-11 chemotherapy. TS and Topo-I immunostaining was observed in 76% and 43% of tumours, respectively, resulting in a significant relationship within each tumour (r=0.365, p<0.004). Patients with different TS tumour expression showed a similar percentage of Objective Clinical Response, OR (40% vs. 28% of OR in low and high TS-expressing tumours, respectively, p=ns); also, patients with different Topo-I tumour expression did not show a different probability of OR (39% vs. 29% of OR in high and low Topo-I expressing tumours, respectively; p=ns). The tumour expression of these 2 biomarkers also did not impact on time to progression and overall survival of patients. Furthermore, the combined analysis of TS and Topo-I tumour status did not permit to individualize subgroups of patients with different probability of OR. With multivariate analysis, only patient Performance Status significantly impacted on OS (Hazard ratio 4.87; p=0.02) of these patients. We can conclude that high TS tumour expression seems not to preclude a clinical activity for 5-FU/CPT-11 polichemotherapy in advanced colorectal cancer patients; furthermore, clinical response and prognosis of colorectal cancer patients treated with 5-FU/CPT-11 regimen do not differ in tumours with different TS or Topo-I expression.

Anticancer drug response and expression of molecular markers in early-passage xenotransplanted colon carcinomas

Despite some success in the treatment of colorectal carcinomas, novel rational therapies targeting specific cancer-related molecules are under development and urgently needed. These approaches need careful preclinical evaluation in models that closely mirror the clinical situation. Therefore, we established a panel of 15 xenotransplantable tumours directly from fresh surgical material. We showed that both the histology and expression of tumour-associated markers (Epithelial Cell Adhesion molecule (EpCAM), E-cadherin, carcinoembryonic antigen (CEA)) could be maintained during passaging in nude mice. Xenotransplanted tumours were characterised for chemosensitivity and revealed a response rate of 5/15 (33%) for 5-fluorouracil (5-FU), 15/15 (100%) for irinotecan and 8/14 (57%) for oxaliplatin. 5 patients out of 15 were treated with cytostatics because of synchronous metastases. The response to chemotherapy in these patients coincided very closely with the response of the individual xenografts. All of the xenografts expressed the proliferation marker Ki67 and the nuclear enzyme, Topoisomerase IIalpha (Topo IIalpha) at the protein level. Most of the xenografts also expressed the tumour suppressor, p53 (9/14) and the nuclear enzyme Topoisomerase Ialpha (Topo Ialpha) (13/14) at the protein level. Interestingly, the presence of a K-ras mutation in codon 12 (5/15 xenografts) coincided with a low response rate towards oxaliplatin. This observation needs further confirmation using a larger number of tumours. In conclusion, we were able to establish transplantable xenografts suitable to mimic the clinical situation. These well characterised models are useful tools for the preclinical development of novel therapeutic approaches and for investigating translational research aspects.

Topoisomerase I levels in white blood cells of patients with ovarian cancer treated with paclitaxel-cisplatin-topotecan in a phase I study

Topotecan stabilizes the topoisomerase I (Topo I) cleavable complex. We measured Topo I levels in white blood cells of patients with ovarian cancer treated with topotecan. Topotecan was given i.v. daily x 5 q 3 weeks in combination with paclitaxel (1 day before topotecan) and cisplatin (just prior topotecan). Our aim was to correlate Topo I levels to pharmacokinetics and toxicity. Topo I levels were determined using Western blotting and were expressed relative to the Topo I level present in 10 microg cell lysate of the human IGROV1 ovarian cancer cell line. We found no correlation between Topo I levels and (non-)hematological toxicity. Topo I levels after the fifth topotecan infusion were significantly negatively correlated with the AUC of topotecan (R = -0.64, p = 0.026), in contrast with Topo I levels prior to (R = -0.25, p = 0.4) and after (R = -0.30, p = 0.3) the first topotecan infusion. Topo I levels after the fifth topotecan infusion (48 +/- 27%, mean +/- SD) were higher than Topo I levels prior to and after the first topotecan infusion (3.0 +/- 4.7 and 2.7 +/- 3.6%, respectively) (p = 0.001). In conclusion, we detected a significant inverse correlation between Topo I level and topotecan AUC at day 5, and we found increasing Topo I levels during a daily x 5 schedule of treatment with topotecan.

Irinotecan (CPT-11): recent developments and future directions--colorectal cancer and beyond

Since its approval in the United States in 1996, irinotecan (CPT-11, Camptosar, Pharmacia Corp.; Peapack, NJ) has undergone extensive clinical evaluation. In the past five years, the focus of development has evolved from evaluation of single-agent activity in refractory disease settings to evaluation of front-line irinotecan-based combination chemotherapy regimens and integration of irinotecan into combined modality regimens. Important studies have been performed clarifying the role of irinotecan in treating colorectal and other gastrointestinal cancers, small cell and non-small cell lung cancer, and a variety of other malignancies. Preclinical studies performed in conjunction with these clinical trials have also provided significant insights into the pharmacology, metabolism, mechanisms of resistance, and molecular determinants of response. This review summarizes that progress, focusing on the achievements of the past five years.