Faculty Bibliography

PURPOSE/OBJECTIVE:We report here on the tolerance of a carboplatin-'divided dose' paclitaxel (given on days 1 and 11) regimen in chemotherapy-naïve patients with resected and staged endometrial epithelial neoplasms deemed at high-risk of recurrence or early stage epithelial high-grade serous tubo-ovarian adenocarcinomas after risk-reducing surgery. More recently, we applied this regimen as neoadjuvant chemotherapy for advanced ovarian cancer presentations. METHODS:A retrospective chart review of patients receiving this day 1, 11 paclitaxel regimens in combination with carboplatin at AUC 6 every 3 weeks since 2004 was carried out by the second author with subsequent updates by the first and third authors. Tolerance over the first three cycles was analyzed. RESULTS:A total of 27 women were treated with at least three cycles of this paclitaxel 'divided dose' schedule combined with carboplatin: 6 had endometrial adenocarcinoma, 9 had early stage ovarian cancer, and 12 received it as part of neoadjuvant therapy prior to undergoing cytoreductive surgery. Only 14 of 27 patients required dose reductions to complete the first three cycles of treatment. CONCLUSIONS:A median of three cycles of divided dose paclitaxel (D1, D11) concurrent with carboplatin dosed every 3 weeks was found to be safe and feasible as adjuvant to surgery in early endometrial and ovarian cancers or as neoadjuvant treatment in chemotherapy-naive women with ovarian cancer.

PURPOSE: Diagnosing heparin-induced thrombocytopenia, a potentially catastrophic immune-mediated disorder, continues to pose significant challenges for clinicians, as both clinical and laboratory tools lack specificity. There is mounting evidence supporting a positive correlation between definitive heparin-induced thrombocytopenia and optical density (OD) positivity from the widely available anti-platelet factor 4 enzyme-linked immunosorbent assays (PF4 ELISAs). However, the clinical features distinguishing these patients remain poorly understood. PATIENTS AND METHODS: To better characterize this group, we conducted a case-controlled, retrospective chart review of patients from two large, urban academic institutions who underwent a PF4 ELISA at a central laboratory. Associations between OD and 18 clinical characteristics were calculated using the Fisher's exact test for categorical variables and Wilcoxon rank-sum test for continuous variables. RESULTS: In total, 184 negative patients (OD <0.7), and 121 positive patients (OD >0.7), including 74 low-positive patients (0.7< OD <1.4) and 47 high-positive patients (OD >1.4) were identified. Several clinical variables were significantly different in the negative group compared with the positive group, including hospital day (P<0.001), previous admission within the past 3 months (P<0.001), and the presence of a new thrombus (P=0.003). However, many of these variables were not different between the negative and low-positive group, and were only distinct between the negative and high-positive group. When the low-positive and high-positive groups were compared, only the 4T score was significantly different (P=0.003). CONCLUSION: These data indicate that those with OD >1.4 form a distinct clinical group and support the clinical utility of the 4T score.

In ovarian cancer, multiple attempts to adjust the standard taxane/platinum doublet by adding cytotoxic therapy or varying scheduling, dosage, and delivery have been met with limited success. Alternative methods to improve the grim prognosis of ovarian cancer, including molecular therapies, are currently under investigation. Efforts have been made to study tyrosine kinase inhibitors (including imatinib and pazopanib), Src kinase inhibitors and histone deacetylase inhibitors (HDACi) in combination with taxanes/platinums in order to improve efficacy. Unfortunately, while many pre-clinical and early phase clinical trials argue that the utilization of these molecular targets may enhance survival, only modest benefit has been seen in larger clinical trials. Other agents that have been evaluated include proteasome inhibitors, folate receptor antagonists, MEK inhibitors and opiate antagonists. In this review, we discuss the mechanisms of these targeted therapies and highlight the current and ongoing clinical trials that utilize these targeted agents in combination with taxanes and platinums in advanced ovarian cancer.

Since their addition to paclitaxel in the oncologists' armamentarium in the early 1990s, several new taxane formulations have been developed. Besides docetaxel and nab-paclitaxel, new analogs with better therapeutic profiles are being investigated. The goals of this next generation of taxanes are to improve the toxicity profile and efficacy, and to overcome resistance patterns. Several new taxanes, including cabazitaxel, paclitaxel poliglumex, paclitaxel+endotag, and polymeric-micellar paclitaxel, have shown clinical efficacy. These chemotherapeutics are part of many ongoing phase II and III studies on various cancer types. In addition, there are immunotoxins that link key antibodies to mitotic spindle inhibitors (trastuzumab emtansine and brentuximab vedotin). Through this mechanism, novel formulations increase cytotoxicity, improve specificity, and create possibilities for drug enhancement.

Sensory neuropathy is the dose-limiting toxicity of paclitaxel and also impacts on the use of docetaxel and other taxanes. The cause of this adverse effect has to do with their mechanism of action against microtubules and its interaction with neuronal cytoskeletal components. The variability of this toxicity is defined by several factors including disease type, taxane class, schedule and dose of the specific drug, patient demographics, and use of taxanes in combination regimens (especially with the platinums that are also neurotoxic). Prevention of life-long neuropathy is only produced if the causative drug is halted - treatments to reverse toxicity have shown only minimal improvement. This review investigates trials defining the clinical factors that determine the therapeutic window of taxanes and the enhanced susceptibility to this toxicity. In addition, case vignettes illustrate the range of clinical manifestations of this toxicity during taxane administration.

Sensory neuropathy is a common but difficult to quantify complication encountered during treatment of various cancers with taxane-containing regimens. Docetaxel, paclitaxel, and its nanoparticle albumin-bound formulation have been extensively studied in randomized clinical trials comparing various dose and schedules for the treatment of breast, lung, and ovarian cancers. This review highlights differences in extent of severe neuropathies encountered in such randomized trials and seeks to draw conclusions in terms of known pharmacologic factors that may lead to neuropathy. This basic knowledge provides an essential background for exploring pharmacogenomic differences among patients in relation to their susceptibility of developing severe manifestations. In addition, the differences highlighted may lead to greater insight into drug and basic host factors (such as age, sex, and ethnicity) contributing to axonal injury from taxanes. Clin Cancer Res; 19(17); 4570-7. (c)2013 AACR.

A 10-year-old boy with osteosarcoma and normal renal function manifested laboratory evidence of impending renal toxicity and extreme elevation of aspartate aminotrasferase and alanine aminotransferase within 2 hours after the completion of a 4-hour infusion of high-dose methotrexate (MTX) (12 g/m2), and went on to develop acute renal failure with life-threatening hyperkalemia 29 hours later. Although his renal function recovered completely with high-dose leucovorin, hemodialysis, charcoal hemoperfusion, and carboxypeptidase G2, we present this case to emphasize that signs of renal toxicity may be present as early as 2 hours after the completion of a 4-hour MTX infusion, and to suggest that monitoring for MTX toxicity should perhaps begin within a few hours after the completion of 4-hour MTX infusion.