Neurotoxicity in ovarian cancer patients on Gynecologic Oncology Group (GOG) protocol 218: characteristics associated with toxicity and the effect of substitution with docetaxel: an NRG Oncology/Gynecologic Oncology Group study.

OBJECTIVES: To describe characteristics associated with neurotoxicity (NT) in advanced ovarian cancer patients treated on Gynecologic Oncology Group 218 and examine effect of substituting docetaxel for paclitaxel in these patients. METHODS: The development of NT was defined as Common Toxicity Criteria grade (G)≥1. The association between substitution with docetaxel and NT improvement was explored with generalized estimating equations adjusting for treatment cycle and NT grading at previous cycle. RESULTS: Of 1864 evaluable patients, 1329 (71%) developed G≥1 NT during the study. Nearly half appeared within the first two cycles of chemotherapy, with 31% experiencing G≥2. Older patients or those with worse quality of life (QoL) scores at baseline (p<0.05) were more likely to experience NT. One-hundred-six patients received docetaxel as substitute for paclitaxel. Of them, 47 patients started with docetaxel at cycle one due to reaction to paclitaxel (n=32), fear of NT (n=4), and other reasons (n=11), whereas 59 patients switched to docetaxel during cycle 2-6 due to NT (n=32), reaction to paclitaxel (n=19), and other reasons (n=8). Although the protocol instructed otherwise, the majority continued paclitaxel despite G≥2 NT symptoms. There was no evidence that substitution with docetaxel improved NT (Odds Ratio: 1.57; 95% CI 0.98-2.54; p>0.05). Of 59 patients who switched to docetaxel, only seven (12%) discontinued taxane prior to chemotherapy completion. A roughly equal chance of worsening NT was reported on paclitaxel (6%) as on docetaxel (5%). CONCLUSIONS: Age and worse QoL at baseline are associated with NT. Substitution of docetaxel did not improve NT symptoms.

Protein profiling of ovarian cancers by immunohistochemistry to identify potential target pathways.

BACKGROUND: To determine the protein expression profile (PEP) of primary and recurrent ovarian cancer patients in order to predict therapeutic targets for chemotherapy. METHODS: Tissue samples were submitted for PEP in two formats, including formalin-fixed paraffin-embedded tissue for immunohistochemistry (IHC) and fresh frozen tissue for oligonucleotide microarray (MA) gene expression assays. Specimens were analyzed for 18 protein markers and 88 MA genes. A series of Generalized Linear Models (GLM) was used to predict the proportion of positive results by histology for each biomarker. RESULTS: Four hundred and twenty-eight specimens were analyzed for IHC and 67 specimens for MA analysis. The majority of specimens, 82%, were serous histology and 35.3% of specimens were poorly differentiated. Sixty percent of specimens were advanced stage, 62% were from a primary diagnosis, and 53% were obtained from a metastatic site. BCRP, ER, MGMT, and RRM1 proteins were overexpressed in 85%, 47%, 93%, and 47% of serous carcinomas, respectively. The MGMT and RRM1 biomarkers were significantly overexpressed in serous (p < .001) and endometrioid (p = .01) histologies when compared to clear cell histology. MGMT was significantly elevated in 93% of serous and endometrioid samples, compared to 62% of samples with clear cell histology. Those proteins most often underexpressed included Her2/neu, SPARC, and c-kit, seen in less than 1%, 4%, and 5% of specimens, respectively. CONCLUSIONS: PEP is a reliable and effective way of analyzing ovarian cancer specimens. PEP target identification does not appear to vary significantly with site evaluated, ovarian or other abdominal pelvic tissue, or primary versus recurrent disease. Variability in the expression of drug targets, including BCRP, ER, MGMT, and RRM1 could impact decision making pertaining to which therapeutic strategies carry the best chances for controlling disease.