Posterior reversible encephalopathy syndrome (PRES) after bevacizumab therapy for metastatic colorectal cancer

Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognizable neuro-clinical syndrome. Clinical and neurological manifestations of PRES include hypertension, headache, encephalopathy, seizures, and symmetrical white matter changes on brain MRI. Most common precipitants of PRES are acute medical illness, hypertensive crisis, eclampsia, immunosuppressive therapy, and chemotherapy. Bevacizumab is a monoclonal antibody that halts angiogenesis by inhibiting vascular endothelial growth factor. It has gained widespread popularity in oncology world especially for metastatic and recurrent cancers due to its inherent ability to stop angiogenesis; a vital step for tumor growth. Bevacizumab has also been implicated as the cause of PRES due to dysregulation of the blood-brain barrier. We are reporting a case of PRES induced by Bevacizumab in a patient of colorectal cancer.

Targeted therapy in older patients with solid tumors

The introduction of targeted therapy has ushered in the era of personalized medicine in cancer therapy. The increased understanding of tumor heterogeneity has led to the determination of specific targets that can be exploited in treatment. This review highlights approved drugs in different therapeutic classes, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, drugs targeted to the human epidermal growth factor receptor 2, BRAF-mutation targeted drugs, anti-epidermal growth factor receptor inhibitors, and anti-vascular endothelial growth factor therapy. There have not been elderly patient-specific trials of these therapies. Most of the data are extrapolated from larger trials in which older patients generally were a fraction of the participants. Therapeutic recommendations are made on the basis of this analysis with the recognition that the older clinical trial participants may not be representative of patients seen in daily practice. Patient selection and geriatric evaluation are critical for appropriate drug selection, dosing, and monitoring. With care, these therapies are a major step forward in the safe and effective treatment of older patients with cancer.

Relative effectiveness and safety of chemotherapy in elderly and nonelderly patients with stage III colon cancer: a systematic review

BACKGROUND

Chemotherapy effectiveness in clinical practice may differ from the efficacy demonstrated in clinical trials, particularly among populations underrepresented in clinical trials, such as elderly patients with cancer. This review aims to examine the relative effectiveness of chemotherapy for stage III colon cancer in elderly versus nonelderly patients.

METHODS

A systematic literature review was conducted using the Agency for Healthcare Research and Quality approach. Literature searches were performed in Medline and Evidence-Based Medicine Reviews databases. Chemotherapy regimens approved for stage III colon cancer were reviewed. Four effectiveness and 15 safety outcomes were extracted.

RESULTS

From 708 identified articles, 25 articles provided data on the relative effectiveness and safety of chemotherapy among elderly versus nonelderly patients. Four of 14 studies showed lower overall survival treatment effects, whereas one of five and one of four studies indicated more favorable treatment effects for time to progression and overall response rate. Grade 3 or 4 adverse events were higher among elderly patients for cardiac disorder (2/5 studies), leukopenia (1/5), neutropenia (4/16), thrombocytopenia (2/13), febrile neutropenia (1/4), infection (2/10), dehydration (2/6), diarrhea (6/20), and fatigue (6/13). Grade 3 or 4 adverse events were lower for neutropenia (2/16 studies), nausea/vomiting (1/16), and neuropathy (1/9).

CONCLUSION

The majority of the evidence suggests that chemotherapy has similar relative effectiveness and safety for patients >65 years of age versus younger patients with stage III colon cancer. When differences are reported, treatment effects are more often worse among the elderly. This review suggests that without other reasons for withholding treatment, elderly patients should receive chemotherapy as often as nonelderly patients.

Bevacizumab in older patients with advanced colorectal or breast cancer

The incidence of colorectal and breast cancer is growing among the 550 million living people aged 65 or older. Bevacizumab was the first anti-angiogenic agent approved for the treatment of the advanced phase of these cancers. Although older chronological age still hampers the use of modern treatments, there is a widespread awareness that chronological and physiological (i.e. functional) ages may largely differ, and that seniority itself should not be a stringent limit for the introduction of anti-angiogenics. However, the use of bevacizumab in the general older population is questionable. There is limited evidence of a favorable risk-to-benefit ratio, with efficacy data deriving from clinical trials that selected only elderly patients in rather good health. While summarizing the recent advances, this review highlights specific clinical features characterizing those older patients who may benefit the most from receiving bevacizumab.

Treatment of metastatic colorectal cancer in the elderly

OPINION STATEMENT

Metastatic colorectal cancer (CRC) is the second leading cause of cancer related mortality in the United States. The median age of patients at diagnosis is over 70, so as the American population ages, it can be expected that the incidence of CRC will also increase. There is limited prospective data regarding the safety and efficacy of chemotherapy in elderly patients with metastatic CRC. However, the data that are available suggest that elderly patients with a good performance status have a similar likelihood of response to currently available chemotherapy, though perhaps a somewhat higher likelihood of toxicities such as myelosuppression. This paper reviews the available data and recommendations for the treatment of this patient population.

Ambulatory monitoring detects sorafenib-induced blood pressure elevations on the first day of treatment

PURPOSE

Hypertension is a mechanism-based toxicity of sorafenib and other cancer therapeutics that inhibit the vascular endothelial growth factor (VEGF) signaling pathway. This prospective, single-center, cohort study characterized ambulatory blood pressure monitoring as an early pharmacodynamic biomarker of VEGF signaling pathway inhibition by sorafenib.

EXPERIMENTAL DESIGN

Fifty-four normotensive advanced cancer patients underwent 24-hour ambulatory blood pressure monitoring before and between days 6 and 10 of sorafenib therapy. After blood pressure changes were detected among the first cohort within 10 days, ambulatory blood pressure monitoring was done during the first 24 hours of treatment for the second cohort.

RESULTS

For the entire patient population, the blood pressure increase [mean systolic, +10.8 mm Hg; 95% confidence interval (95% CI), 8.6-13.0; range, -5.2 to +28.7 mm Hg; mean diastolic, +8.0 mm Hg; 95% CI, 6.3-9.7; range, -4.4 to +27.1 mm Hg] was detected between days 6 and 10 (P < 0.0001 for both) and plateaued thereafter. Variability in blood pressure change did not associate with: age, body size, sex, self-reported race, baseline blood pressure, or steady-state sorafenib plasma concentrations. In the second cohort, the blood pressure elevation was detected during the first 24 hours (mean systolic, +8.2 mm Hg; 95% CI, 5.0-11.3; mean diastolic, +6.5 mm Hg; 95% CI, 4.7-8.3; P < 0.0001 for both).

CONCLUSIONS

Ambulatory blood pressure monitoring detects the blood pressure response to VEGF signaling pathway inhibition by sorafenib during the first 24 hours of treatment. The magnitude of blood pressure elevation is highly variable and unpredictable but could be important in optimizing the therapeutic index of VEGF signaling pathway inhibitor therapy.

Understanding and managing the possible adverse effects associated with bevacizumab

PURPOSE

The adverse events associated with bevacizumab therapy are characterized, and the underlying pathophysiology, risk factors, frequency, and management of these events are described.

SUMMARY

The adverse events associated with bevacizumab include hypertension, proteinuria, thromboembolism, impaired wound healing, bleeding, perforation, reversible leukoencephalopathy syndrome, skin rash, and infusion-related hypersensitivity reactions. Patients should be monitored for these events throughout the course of bevacizumab therapy. Hypertension is by far the most common adverse event associated with bevacizumab. Blood pressure should be routinely monitored, and hypertension should be medically managed with antihypertensive drugs as deemed appropriate during bevacizumab therapy. Patients should be monitored for proteinuria every three to four weeks, and bevacizumab should be discontinued with persistent proteinuria of >2+. Thromboembolic events, impaired wound healing, bowel and nasal septum perforation, and bleeding share similar pathophysiology. Thromboembolic events should be managed in accordance with guidelines established by the American College of Chest Physicians, and bevacizumab should be discontinued for new life-threatening venous or arterial thromboembolism. To minimize the risk of bleeding or impaired wound healing, bevacizumab should be started at least four weeks after surgery or discontinued for at least six to eight weeks before elective surgery. The management of other adverse events is more anecdotal, with relatively few reports of their occurrence with bevacizumab.

CONCLUSION

Many of the potential serious complications of bevacizumab can be averted by close monitoring of patient-specific variables, which should be measured at baseline and then at predetermined intervals throughout the course of therapy to maximize patient safety.

[Chemotherapy of elderly patients with colorectal cancer]

Elderly patients will be the largest group of oncology patients in the future. Because of minimal participation of older patients in randomized clinical trials there is a lack of evidence-based data to make correct decisions with regard to chemotherapy and/or targeted therapy in this age group. Elderly patients have similar benefits from systemic therapies as younger counterparts, but many elders have substantial co-morbidities, which may limit the life expectancy and the effectiveness of systemic therapy. Close collaboration between oncologists and geriatrists will help make decisions on the management of elderly patients suffering from cancer.

Intricacies of bevacizumab-induced toxicities and their management

OBJECTIVE

To review the serious and common toxicities of bevacizumab and describe their incidence, risk factors, presentation, pathophysiology, and management.

DATA SOURCES

Literature for this review article was collected from PubMed, MEDLINE, and the proceedings of the American Society of Clinical Oncology (2000-November 2008). The key terms used in the search were: bevacizumab, vascular endothelial growth factor, angiogenesis inhibitors, toxicity, toxicity management, and adverse event.

STUDY SELECTION AND DATA EXTRACTION

Review articles, preclinical studies, and all published Phase 1-3 clinical trials were reviewed. The references listed in identified articles were examined for additional publications.

DATA SYNTHESIS

The biomedical literature from 2000 to 2008 confirms that bevacizumab carries serious and potentially life-threatening toxicity risks and emphasizes the importance of early recognition, continuous monitoring, and prompt management of these toxicities. Such toxicities include hemorrhage/bleeding, wound healing complications, gastrointestinal perforation, arterial thromboembolism, congestive heart failure, hypertension, proteinuria/nephrotic syndrome, infusion-related hypersensitivity reactions, and reversible posterior leukoencephalopathy syndrome. Patients at the highest risk for these toxicities are individuals with a history of hypertension, thromboembolism, bleeding, cardiovascular disease, or preexisting proteinuria, as these conditions may be exacerbated by bevacizumab use. Additionally, particular tumor types correlate with risk for individual toxicities; for example, patients with squamous non-small-cell lung cancer or rectal cancer have a higher risk of bleeding, those with renal cell carcinoma have a higher proteinuria risk, and patients with colorectal cancer have a higher risk of gastrointestinal perforation. Further investigation is warranted to develop effective management strategies for these toxicities.

CONCLUSIONS

As bevacizumab is becoming widely used in general oncology practice, it is important to understand the toxicities that can arise and to develop practice guidelines for their management.

Outcomes for Elderly, Advanced-Stage Non–Small-Cell Lung Cancer Patients Treated With Bevacizumab in Combination With Carboplatin and Paclitaxel: Analysis of Eastern Cooperative Oncology Group Trial 4599

Purpose

Fit elderly patients with advanced non–small-cell lung cancer (NSCLC) benefit from platinum-based, two-drug chemotherapy. Bevacizumab (B) in combination with carboplatin (C) and paclitaxel (P) improves survival for advanced, nonsquamous NSCLC, as evidenced in Eastern Cooperative Oncology Group (ECOG) 4599. We conducted a subset analysis of ECOG 4599 to determine the outcome for elderly patients.

Patients and Methods

ECOG 4599 randomly assigned patients with advanced nonsquamous NSCLC to PC or to PCB. We analyzed outcome in patients who were at least 70 years of age at the time of study entry. Patient characteristics, efficacy, and toxicity data were compared between PC and PCB for the elderly. Outcomes for elderly and younger patients (< 70 years) treated with PCB were also compared.

Results

Among elderly patients (n = 224; 26%), there was a trend towards higher response rate (29% v 17%; P = .067) and progression-free survival (5.9 v 4.9 months; P = .063) with PCB compared with PC, although overall survival (PCB = 11.3 months; PC = 12.1 months; P = .4) was similar. Grade 3 to 5 toxicities occurred in 87% of elderly patients with PCB versus 61% with PC (P < .001), with seven treatment-related deaths in the PCB arm compared with two with PC. Elderly patients had higher incidence of grade 3 to 5 neutropenia, bleeding, and proteinuria with PCB compared with younger patients.

Conclusion

In elderly NSCLC patients, PCB was associated with a higher degree of toxicity, but no obvious improvement in survival compared with PC. Data from this unplanned, retrospective analysis justify prospective evaluation of the therapeutic index of PCB regimen in elderly patients.