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Darryl Lau, Caleb Rutledge, and Manish K. Aghi

OBJECT

Cushing's disease (CD) can lead to significant morbidity secondary to hormonal sequelae or mass effect from the pituitary tumor. A transsphenoidal approach to resection of the adrenocorticotropic hormone (ACTH)–secreting pituitary adenoma is the first-line treatment. However, in the setting in which patients are unable to undergo surgery, have acute hypercortisolism, or have recurrent disease, medical therapy can play an important role. The authors performed a systematic review to highlight the efficacy of medical treatment of CD and discuss novel molecular insights that could guide the development of future medical treatments of CD.

METHODS

A search on current medical therapies for CD was performed. After individual medical therapeutic agents for CD were identified, each agent underwent a formal systematic search. The phrase “(name of agent) and Cushing's” was used as a search term in PubMed for all years up to 2014. The abstract of each article was reviewed for studies that evaluated the efficacy of medical treatment of CD. Only studies that enrolled at least 20 patients were included in the review.

RESULTS

A total of 11 articles on 6 individual agents were included in this review. Specific medical therapies were categorized based on the level of action: pituitary directed (cabergoline and pasireotide), adrenal/steroidogenesis directed (ketoconazole, metyrapone, and mitotane), and end-tissue directed/cortisol receptors (mifepristone). The studies identified consisted of a mix of retrospective reviews and small clinical trials. Only pasireotide and mifepristone have undergone Phase III clinical trials, from which they garnered FDA approval for the treatment of patients with CD. Overall, agents targeting ACTH secretion and steroidogenesis were found to be quite effective in reducing urine free cortisol (UFC) to levels near normal. A significant reduction in UFC was observed in 45%–100% of patients and a majority of patients gained clinical improvement. Similarly, inhibition at the end-tissue level led to clinical improvement in 87% of patients. However, side-effect rates associated with these drugs are high (up to 88%). Ketoconazole has been shown to enhance tumor appearance on MRI to facilitate pituitary resection. Promising molecular targets have been identified, including epidermal growth factor receptor, retinoic acid receptors, and cyclin dependent kinases. These pathways have been linked to the regulation of pro-opiomelanocortin expression, ACTH secretion, and tumor growth.

CONCLUSIONS

Despite encouraging Phase III clinical trials leading to FDA approval of 2 agents for treatment of patients with CD, no agent has yet produced results comparable to resection. As a result, the molecular insights gained into CD pathogenesis will need to continue to be expanded until they can lead to the development of medical therapies for CD with a favorable side-effect profile and efficacy comparable to resection. Ideally these agents should also reduce tumor size, which could potentially permit their eventual discontinuation.

Free access

Darryl Lau, Stephen T. Magill, and Manish K. Aghi

Object

Glioblastoma is the most aggressive and diffusely infiltrative primary brain tumor. Recurrence is expected and is extremely difficult to treat. Over the past decade, the accumulation of knowledge regarding the molecular and genetic profile of glioblastoma has led to numerous molecularly targeted therapies. This article aims to review the literature and highlight the mechanisms and efficacies of molecularly targeted therapies for recurrent glioblastoma.

Methods

A systematic search was performed with the phrase “(name of particular agent) and glioblastoma” as a search term in PubMed to identify all articles published up until 2014 that included this phrase in the title and/or abstract. The references of systematic reviews were also reviewed for additional sources. The review included clinical studies that comprised at least 20 patients and reported results for the treatment of recurrent glioblastoma with molecular targeted therapies.

Results

A total of 42 articles were included in this review. In the treatment of recurrent glioblastoma, various targeted therapies have been tested over the past 10–15 years. The targets of interest include epidermal growth factor receptor, vascular endothelial growth factor receptor, platelet-derived growth factor receptor, Ras pathway, protein kinase C, mammalian target of rapamycin, histone acetylation, and integrins. Unfortunately, the clinical responses to most available targeted therapies are modest at best. Radiographic responses generally range in the realm of 5%–20%. Progression-free survival at 6 months and overall survival were also modest with the majority of studies reporting a 10%–20% 6-month progression-free survival and 5- to 8-month overall survival. There have been several clinical trials evaluating the use of combination therapy for molecularly targeted treatments. In general, the outcomes for combination therapy tend to be superior to single-agent therapy, regardless of the specific agent studied.

Conclusions

Recurrent glioblastoma remains very difficult to treat, even with molecular targeted therapies and anticancer agents. The currently available targeted therapy regimens have poor to modest activity against recurrent glioblastoma. As newer agents are actively being developed, combination regimens have provided the most promising results for improving outcomes. Targeted therapies matched to molecular profiles of individual tumors are predicted to be a critical component necessary for improving efficacy in future trials.

Restricted access

Ankush Chandra, Jacob S. Young, Cecilia Dalle Ore, Fara Dayani, Darryl Lau, Harsh Wadhwa, Jonathan W. Rick, Alan T. Nguyen, Michael W. McDermott, Mitchel S. Berger, and Manish K. Aghi

OBJECTIVE

Glioblastoma (GBM) carries a high economic burden for patients and caregivers, much of which is associated with initial surgery. The authors investigated the impact of insurance status on the inpatient hospital costs of surgery for patients with GBM.

METHODS

The authors conducted a retrospective review of patients with GBM (2010–2015) undergoing their first resection at the University of California, San Francisco, and corresponding inpatient hospital costs.

RESULTS

Of 227 patients with GBM (median age 62 years, 37.9% females), 31 (13.7%) had Medicaid, 94 (41.4%) had Medicare, and 102 (44.9%) had private insurance. Medicaid patients had 30% higher overall hospital costs for surgery compared to non-Medicaid patients ($50,285 vs $38,779, p = 0.01). Medicaid patients had higher intensive care unit (ICU; p < 0.01), operating room (p < 0.03), imaging (p < 0.001), room and board (p < 0001), and pharmacy (p < 0.02) costs versus non-Medicaid patients. Medicaid patients had significantly longer overall and ICU lengths of stay (6.9 and 2.6 days) versus Medicare (4.0 and 1.5 days) and privately insured patients (3.9 and 1.8 days, p < 0.01). Medicaid patients had similar comorbidity rates to Medicare patients (67.8% vs 68.1%), and both groups had higher comorbidity rates than privately insured patients (37.3%, p < 0.0001). Only 67.7% of Medicaid patients had primary care providers (PCPs) versus 91.5% of Medicare and 86.3% of privately insured patients (p = 0.009) at the time of presentation. Tumor diameter at diagnosis was largest for Medicaid (4.7 cm) versus Medicare (4.1 cm) and privately insured patients (4.2 cm, p = 0.03). Preoperative (70 vs 90, p = 0.02) and postoperative (80 vs 90, p = 0.03) Karnofsky Performance Scale (KPS) scores were lowest for Medicaid versus non-Medicaid patients, while in subgroup analysis, postoperative KPS score was lowest for Medicaid patients (80, vs 90 for Medicare and 90 for private insurance; p = 0.03). Medicaid patients had significantly shorter median overall survival (10.7 months vs 12.8 months for Medicare and 15.8 months for private insurance; p = 0.02). Quality-adjusted life year (QALY) scores were 0.66 and 1.05 for Medicaid and non-Medicaid patients, respectively (p = 0.036). The incremental cost per QALY was $29,963 lower for the non-Medicaid cohort.

CONCLUSIONS

Patients with GBMs and Medicaid have higher surgical costs, longer lengths of stay, poorer survival, and lower QALY scores. This study indicates that these patients lack PCPs, have more comorbidities, and present later in the disease course with larger tumors; these factors may drive the poorer postoperative function and greater consumption of hospital resources that were identified. Given limited resources and rising healthcare costs, factors such as access to PCPs, equitable adjuvant therapy, and early screening/diagnosis of disease need to be improved in order to improve prognosis and reduce hospital costs for patients with GBM.

Free access

Ankush Chandra, Jonathan W. Rick, Cecilia Dalle Ore, Darryl Lau, Alan T. Nguyen, Diego Carrera, Alexander Bonte, Annette M. Molinaro, Philip V. Theodosopoulos, Michael W. McDermott, Mitchel S. Berger, and Manish K. Aghi

OBJECTIVE

Glioblastoma (GBM) is an aggressive brain malignancy with a short overall patient survival, yet there remains significant heterogeneity in outcomes. Although access to health care has previously been linked to impact on prognosis in several malignancies, this question remains incompletely answered in GBM.

METHODS

This study was a retrospective analysis of 354 newly diagnosed patients with GBM who underwent first resection at the authors’ institution (2007–2015).

RESULTS

Of the 354 patients (median age 61 years, and 37.6% were females), 32 (9.0%) had no insurance, whereas 322 (91.0%) had insurance, of whom 131 (40.7%) had Medicare, 45 (14%) had Medicaid, and 146 (45.3%) had private insurance. On average, insured patients survived almost 2-fold longer (p < 0.0001) than those who were uninsured, whereas differences between specific insurance types did not influence survival. The adjusted hazard ratio (HR) for death was higher in uninsured patients (HR 2.27 [95% CI 1.49–3.33], p = 0.0003). Age, mean household income, tumor size at diagnosis, and extent of resection did not differ between insured and uninsured patients, but there was a disparity in primary care physician (PCP) status—none of the uninsured patients had PCPs, whereas 72% of insured patients had PCPs. Postoperative adjuvant treatment rates with temozolomide (TMZ) and radiation therapy (XRT) were significantly less in uninsured (TMZ in 56.3%, XRT in 56.3%) than in insured (TMZ in 75.2%, XRT in 79.2%; p = 0.02 and p = 0.003) patients. Insured patients receiving both agents had better prognosis than uninsured patients receiving the same treatment (9.1 vs 16.34 months; p = 0.025), suggesting that the survival effect in insured patients could only partly be explained by higher treatment rates. Moreover, having a PCP increased survival among the insured cohort (10.7 vs 16.1 months, HR 1.65 [95% CI 1.27–2.15]; p = 0.0001), which could be explained by significant differences in tumor diameter at initial diagnosis between patients with and without PCPs (4.3 vs 4.8 cm, p = 0.003), and a higher rate of clinical trial enrollment, suggesting a critical role of PCPs for a timelier diagnosis of GBM and proactive cancer care management.

CONCLUSIONS

Access to health care is a strong determinant of prognosis in newly diagnosed patients with GBM. Any type of insurance coverage and having a PCP improved prognosis in this patient cohort. Higher rates of treatment with TMZ plus XRT, clinical trial enrollment, fewer comorbidities, and early diagnosis may explain survival disparities. Lack of health insurance or a PCP are major challenges within the health care system, which, if improved upon, could favorably impact the prognosis of patients with GBM.