Possible Effects of Psychological Therapy on Survival Duration in Cancer Patients

Population pharmacokinetics of clofarabine and its metabolite 6-ketoclofarabine in adult and pediatric patients with cancer

Clofarabine for injection is a second-generation nucleoside analog approved in the United States (Clolar(®)) and Europe (Evoltra(®)) for the treatment of pediatric relapsed or refractory acute lymphoblastic leukemia. This report describes the population pharmacokinetics of clofarabine and its metabolite 6-ketoclofarabine in adult and pediatric patients with hematologic malignancies or solid tumors. Clofarabine pharmacokinetics were best described by a 2-compartment model with linear elimination and first-order absorption after oral administration. Clofarabine was rapidly absorbed following oral administration with a mean absorption time of less than 2 h and bioavailability of 57.5%. The important covariates affecting clofarabine pharmacokinetics were age, weight, and estimated creatinine clearance (eCrCL). No difference in pharmacokinetics was observed between sexes, races, or disease type. The elimination half-life was dependent on all the covariates but was generally less than 7 h in all cases. A difference in clofarabine pharmacokinetics was observed between adults and children. For a pediatric patient 3 years old weighing 16 kg with an eCrCL of 138 mL/min/1.73 m(2), the population estimates for total systemic clearance and volume of distribution at steady-state were 18.3 L/h (1.14 L/h/kg) and 92.9 L (5.81 L/kg), respectively. α- and β-half-life were 0.9 and 4.4 h, respectively. For an elderly patient 82 years old weighing 96 kg with an eCrCL of 46 mL/min/1.73 m(2), the population estimates for CL and Vdss were 21.5 L/h (0.22 L/h/kg) and 257.4 L (268 L/kg), respectively. α- and β-half-life were 0.5 and 10.6 h, respectively. Because of the difference in pharmacokinetics, adults have higher exposure than children given a similar dose standardized to body surface area. The exact mechanism of this difference is not understood. As eCrCL decreased, exposure increased due to reduced total systemic clearance. In the case of moderate (eCrCL 30 to 60 mL/min/1.73 m(2)) and severe (eCrCL <30 mL/min/1.73 m(2)) renal impairment, dose reduction may be needed to maintain similar exposure in an equivalent patient of the same age, weight, and normal renal function after both oral and intravenous administration. 6-Ketoclofarabine was a minor metabolite with peak plasma concentrations occurring about 1 h after the start of the infusion and having a metabolite ratio averaging less than 5% and not more than 8% for any particular individual. 6-Ketoclofarabine was rapidly cleared from plasma with an average apparent half-life of 4.9 h (range 3.9 to 6.2 h). No accumulation of 6-ketoclofarabine was observed with predose samples all below the limit of quantification on Days 8 and 15. Further monitoring of 6-ketoclofarabine is not required in future studies.

Understanding the causes of depression among prostate cancer patients: development of the Effects of Prostate Cancer on Lifestyle Questionnaire

OBJECTIVE

Depression among prostate cancer patients remains a major source of distress for them and their families, has been linked with suicide, and has been shown to contribute to poorer longterm treatment outcomes. Most psychological assessment strategies focus upon the presence of depressive symptomatology without identifying the specific causal antecedents that lead to depression among this patient group, although this underlies effective individually-oriented treatment planning and delivery.

METHOD

150 prostate cancer patients completed self reports on anxiety, depression and lifestyle changes that they had experienced as a result of receiving a diagnosis of, and treatment for their cancer. The principal instrument being investigated was a measure of 50 lifestyle changes that had been developed from previous interviews with prostate cancer patients.

RESULTS

Data indicated significant relationships between depression scores and the frequency of unpleasant lifestyle changes and the ratings that participants gave to these changes, supporting a model of depression as an adaptive withdrawal from noxious stimuli and environments. Psychometric data provided a method of deleting several items so that a clinical analysis and a research scale of 36 items was developed for use with prostate cancer patients.

CONCLUSION

Implications for treatment are discussed in terms of accurate identification of antecedents that lead to a further understanding of depression as an 'adaptive' response of active withdrawal from noxious environments.

Selecting a specific pre- or postoperative adjuvant therapy for individual patients with operable gastric cancer

Although the very high locoregional recurrence rates reported with limited D0/D1 surgery can be reduced with extended D2 gastrectomy for operable gastric cancer, overall relapse and survival rates remain poor and can only be improved with adequate perioperative adjuvant treatment. However, despite intensive research, no regimen has been established as standard. Meta-analyses have demonstrated a marginal survival benefit with adjuvant chemotherapy. Two recent large randomized trials for operable gastric cancer, the MAGIC trial and the INT-0116 trial, provide evidence that some patients may benefit from perioperative chemotherapy and chemoradiation, respectively. However, while both trials suggest an overall survival benefit with adjuvant treatment, they don't provide the harm-benefit ratio for specific subsets of patients wih different extent of surgery (D1 or D2) and tumor stage (early [T1,2]/advanced [T3,4]). This lack of evidence complicates current therapeutic adjuvant decisions. Estimating the risk of local and distant recurrence (high, moderate or low) after D1 or D2 surgery in various tumor stages and the expected harm-benefit ratio, the authors provide useful information for decisions on adjuvant chemotherapy with or withour radiotherapy in individual patients. Research on newer cytotoxic and targeted agents may improve treatment efficacy. Simultaneously, advances with microarray-based gene-expression profiling signatures may improve individualized treatment decisions. However, the validation and translation of these genomic classifiers as biomarkers into a completed 'bench-to-bedside' cycle for tailoring treatment to individuals is a major challenge and limits inflated expectations.