Taxane monotherapy regimens for the treatment of recurrent epithelial ovarian cancer.

BACKGROUND: Ovarian cancer is the seventh most frequent cancer diagnosis worldwide, and the eighth leading cause of cancer mortality. Epithelial ovarian cancer is the most common kind, accounting for 90% of cases. First-line therapy for women with epithelial ovarian cancer consists of a combination of cytoreductive surgery and platinum and taxane-based chemotherapy. However, more than 50% of women with epithelial ovarian cancer will experience a relapse and require further chemotherapy and at some point develop resistance to platinum-based drugs. Currently, guidance on the use of most chemotherapy drugs, including taxanes, is unclear for women whose epithelial ovarian cancer has recurred. Paclitaxel, topotecan, pegylated liposomal doxorubicin hydrochloride, trabectedin and gemcitabine are all licensed for use in the UK at the discretion of clinicians, following discussion with the women as to potential adverse effects. Taxanes can be given in once-weekly regimens (at a lower dose) or three-weekly regimens (at a higher dose), which may have differences in the severity of side effects and effectiveness. As relapsed disease suggests incurable disease, it is all the more important to consider side effects and the impact of treatment schedules, as well as quality of life, and not only the life-prolonging effects of treatment. OBJECTIVES: To assess the efficacy and toxicity of different taxane monotherapy regimens for women with recurrent epithelial ovarian, tubal or primary peritoneal cancer. SEARCH METHODS: We searched CENTRAL, MEDLINE and Embase, up to 22 March 2022. Other related databases and trial registries were searched as well as grey literature and no additional studies were identified. A total of 1500 records were identified. SELECTION CRITERIA: We included randomised controlled trials of taxane monotherapy for adult women diagnosed with recurrent epithelial ovarian, tubal or primary peritoneal cancer, previously treated with platinum-based chemotherapy. We included trials comparing two or more taxane monotherapy regimens. Participants could be experiencing their first recurrence of disease or any line of recurrence. DATA COLLECTION AND ANALYSIS: Two review authors screened, independently assessed studies, and extracted data from the included studies. The clinical outcomes we examined were overall survival, response rate, progression-free survival, neurotoxicity, neutropenia, alopecia, and quality of life. We performed statistical analyses using fixed-effect and random-effects models following standard Cochrane methodology. We rated the certainty of evidence according to the GRADE approach. MAIN RESULTS: Our literature search yielded 1500 records of 1466 studies; no additional studies were identified by searching grey literature or handsearching. We uploaded the search results into Covidence. After the exclusion of 92 duplicates, we screened titles and abstracts of 1374 records. Of these, we identified 24 studies for full-text screening. We included four parallel-group randomised controlled trials (RCTs). All trials were multicentred and conducted in a hospital setting. The studies included 981 eligible participants with recurrent epithelial ovarian cancer, tubal or primary peritoneal cancer with a median age ranging between 56 to 62 years of age. All participants had a WHO (World Health Organization) performance status of between 0 to 2. The proportion of participants with serous histology ranged between 56% to 85%. Participants included women who had platinum-sensitive (71%) and platinum-resistant (29%) relapse. Some participants were taxane pre-treated (5.6%), whilst the majority were taxane-naive (94.4%). No studies were classified as having a high risk of bias for any of the domains in the Cochrane risk of bias tool. We found that there may be little or no difference in overall survival (OS) between weekly paclitaxel and three-weekly paclitaxel, but the evidence is very uncertain (risk ratio (RR) of 0.94, 95% confidence interval (CI) 0.66 to 1.33, two studies, 263 participants, very low-certainty evidence). Similarly, there may be little or no difference in response rate (RR of 1.07, 95% CI 0.78 to 1.48, two studies, 263 participants, very low-certainty evidence) and progression-free survival (PFS) (RR of 0.83, 95% CI 0.46 to 1.52, two studies, 263 participants, very low-certainty evidence) between weekly and three-weekly paclitaxel, but the evidence is very uncertain. We found differences in the chemotherapy-associated adverse events between the weekly and three-weekly paclitaxel regimens. The weekly paclitaxel regimen may result in a reduction in neutropenia (RR 0.51, 95% 0.27 to 0.95, two studies, 260 participants, low-certainty evidence) and alopecia (RR 0.58, 95% CI 0.46 to 0.73, one study, 205 participants, low-certainty evidence). There may be little or no difference in neurotoxicity, but the evidence was very low-certainty and we cannot exclude an effect (RR 0.53, 95% CI 0.19 to 1.45, two studies, 260 participants). When examining the effect of paclitaxel dosage in the three-weekly regimen, the 250 mg/m2 paclitaxel regimen probably causes more neurotoxicity compared to the 175 mg/m2 regimen (RR 0.41, 95% CI 0.21 to 0.80, one study, 330 participants, moderate-certainty evidence). Quality-of-life data were not extractable from any of the included studies. AUTHORS' CONCLUSIONS: Fewer people may experience neutropenia when given weekly rather than three-weekly paclitaxel (low-certainty evidence), although it may make little or no difference to the risk of developing neurotoxicity (very low-certainty evidence). This is based on the participants receiving lower doses of drug more often. However, our confidence in this result is low and the true effect may be substantially different from the estimate of the effect. Weekly paclitaxel probably reduces the risk of alopecia, although the rates in both arms were high (46% versus 79%) (low-certainty evidence). A change to weekly from three-weekly chemotherapy could be considered to reduce the likelihood of toxicity, as it may have little or no negative impact on response rate (very low-certainty evidence), PFS (very low-certainty evidence) or OS (very low-certainty evidence). Three-weekly paclitaxel, given at a dose of 175 mg/m2 compared to a higher dose,probably reduces the risk of neurotoxicity.We are moderately confident in this result; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. A change to 175 mg/m2 paclitaxel (from a higher dose), if a three-weekly regimen is used, probably has little or no negative impact on PFS or OS (very low-certainty evidence).

Collateral sensitivity to cisplatin in KB-8-5-11 drug-resistant cancer cells.

BACKGROUND: KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer. MATERIALS AND METHODS: A Taqman low-density array was used to characterize the expression of 380 genes previously associated with chemoresistance. Identified pathways were further analyzed using cytotoxicity assays, metabolomics and western blots. RESULTS: KB-8-5-11 cells were sensitive to CuSO4 and the glutathione inhibitor buthionine sulphoximine. Expression of ATPase, Cu(2+) transporting alpha (ATP7A) and ATP7B were decreased at the protein and gene levels respectively in KB-8-5-11. KB-8-5-11 had decreased gene expression of glutathione S-transferase pi 1 (GSTP1), GSTA4 and GSTK1. Cisplatin treatment significantly lowered total cellular glutathione in parental KB-3-1 cells. Glutathione also tended to be lower in KB-8-5-11 cells compared to KB-3-1 cells. CONCLUSION: KB-8-5-11 cells have alterations in their copper transporters and glutathione metabolism, contributing to their cisplatin-sensitive phenotype.

PARP Inhibitors as P-glyoprotein Substrates.

The cytotoxicity of PARP inhibitors olaparib, veliparib, and CEP-8983 were investigated in two P-glycoprotein (P-gp) overexpressing drug-resistant cell models (IGROVCDDP and KB-8-5-11). IGROVCDDP and KB-8-5-11 were both resistant to olaparib and resistance was reversible with the P-gp inhibitors elacridar, zosuquidar, and valspodar. In contrast, the P-gp overexpressing models were not resistant to veliparib or CEP-8983. Olaparib and veliparib did not induce protein expression of P-gp in IGROVCDDP or KB-8-5-11 at doses that successfully inhibit PARP. Olaparib therefore appears to be a P-gp substrate. Veliparib and CEP-8983 do not appear to be substrates. Veliparib and CEP-8983 may therefore be more useful in combined chemotherapy regimens with P-gp substrates and may be active in platinum and taxane-resistant ovarian cancer.

The establishment of an ISO compliant cancer biobank for Jordan and its neighboring countries through knowledge transfer and training.

Research studies aimed at advancing cancer prevention, diagnosis, and treatment depend on a number of key resources, including a ready supply of high-quality annotated biospecimens from diverse ethnic populations that can be used to test new drugs, assess the validity of prognostic biomarkers, and develop tailor-made therapies. In November 2011, KHCCBIO was established at the King Hussein Cancer Center (KHCC) with the support of Seventh Framework Programme (FP7) funding from the European Union (khccbio.khcc.jo). KHCCBIO was developed for the purpose of achieving an ISO accredited cancer biobank through the collection, processing, and preservation of high-quality, clinically annotated biospecimens from consenting cancer patients, making it the first cancer biobank of its kind in Jordan. The establishment of a state-of-the-art, standardized biospecimen repository of matched normal and lung tumor tissue, in addition to blood components such as serum, plasma, and white blood cells, was achieved through the support and experience of its European partners, Trinity College Dublin, Biostór Ireland, and accelopment AG. To date, KHCCBIO along with its partners, have worked closely in establishing an ISO Quality Management System (QMS) under which the biobank will operate. A Quality Policy Manual, Validation, and Training plan have been developed in addition to the development of standard operating procedures (SOPs) for consenting policies on ethical issues, data privacy, confidentiality, and biobanking bylaws. SOPs have also been drafted according to best international practices and implemented for the donation, procurement, processing, testing, preservation, storage, and distribution of tissues and blood samples from lung cancer patients, which will form the basis for the procurement of other cancer types. KHCCBIO will be the first ISO accredited cancer biobank from a diverse ethnic Middle Eastern and North African population. It will provide a unique and valuable resource of high-quality human biospecimens and anonymized clinicopathological data to the cancer research communities world-wide.