UGT1A1 Guided Cancer Therapy: Review of the Evidence and Considerations for Clinical Implementation.

Multi-gene assays often include UGT1A1 and, in certain instances, may report associated toxicity risks for irinotecan, belinostat, pazopanib, and nilotinib. However, guidance for incorporating UGT1A1 results into therapeutic decision-making is mostly lacking for these anticancer drugs. We summarized meta-analyses, genome-wide association studies, clinical trials, drug labels, and guidelines relating to the impact of UGT1A1 polymorphisms on irinotecan, belinostat, pazopanib, or nilotinib toxicities. For irinotecan, UGT1A1*28 was significantly associated with neutropenia and diarrhea, particularly with doses ≥ 180 mg/m2, supporting the use of UGT1A1 to guide irinotecan prescribing. The drug label for belinostat recommends a reduced starting dose of 750 mg/m2 for UGT1A1*28 homozygotes, though published studies supporting this recommendation are sparse. There was a correlation between UGT1A1 polymorphisms and pazopanib-induced hepatotoxicity, though further studies are needed to elucidate the role of UGT1A1-guided pazopanib dose adjustments. Limited studies have investigated the association between UGT1A1 polymorphisms and nilotinib-induced hepatotoxicity, with data currently insufficient for UGT1A1-guided nilotinib dose adjustments.

Impact of Primary Tumor Location on First-line Bevacizumab or Cetuximab in Metastatic Colorectal Cancer.

BACKGROUND: Colorectal cancer is one of the most common malignancies in the United States, with a large proportion of patients presenting with metastatic disease or developing a recurrence. Systemic chemotherapy is the mainstay of therapy in this setting. There is a clear benefit in the addition of bevacizumab or cetuximab (for rat sarcoma [RAS] wild type tumors) to oxaliplatin- and irinotecan-based regimens which can be considered for first-line therapy. However, many significant questions remain as to which agent reflects best practice. OBJECTIVE: Our review aimed to elucidate the benefit of adding bevacizumab and cetuximab to initial therapy for metastatic colorectal cancer based on primary tumor location and a variety of other disease- and patient-related factors, addressing the paucity of evidence that currently exists in this area and contributing to current literature and clinical practices. METHODS: The primary endpoints of the study were first Progression-Free Survival (PFS) and Overall Survival (OS). Secondary endpoints included best response to first- and second-line therapies, Treatment- Related Adverse Events (TRAEs), second PFS, cost of therapy, and an assessment of other patient- and disease-related factors affecting PFS and OS. RESULTS: While there were trends towards improved OS in patients with left-sided primary tumors (n=57) compared to those with right-sided disease (n=23), there were no significant differences between the two groups in either primary endpoint. While no differences were found for patients with left- or right- sided tumors stratified by add-on agent, these analyses were limited by the small number of patients receiving cetuximab with first-line therapy (n=4). However, the bevacizumab cohort (n=76) was sizable enough to provide ample data and produce clinically relevant results. Add-on therapy with bevacizumab in our study achieved impressive survival outcomes in both left-sided (median first PFS = 13 months, 95% CI 11-15 months; median OS = 37 months, 95% CI 21-53 months) and right-sided (median first PFS = 13 months, 95% CI 9-17 months; median OS = 37 months, 95% CI 22-52 months) disease. CONCLUSION: These results raised questions regarding the true significance of primary tumor location when selecting bevacizumab or cetuximab for first-line therapy, particularly the current thought of using cetuximab for left-sided tumors. While the superiority of bevacizumab over cetuximab in rightsided disease remained evident upon comparison of our analysis with historical controls, survival outcomes with the agent in our analysis appeared to be similar to that of cetuximab in CRYSTAL, FIRE- 3, and CALGB/SWOG 80405 in left-sided disease. Further study is required to determine if bevacizumab truly does produce similar outcomes to cetuximab in left-sided primary tumors.

Gemcitabine-induced gouty arthritis attacks.

In this case report, we review the experience of a patient who presented with early stage pancreatic cancer (Stage IIb) who underwent a Whipple procedure and adjuvant chemoradiation. The patient's past medical history included early stage colon cancer in remission, post-traumatic-stress-disorder, hypertension, hyperlipidemia, osteoarthritis, gout, and pre-diabetes. Chemotherapy initially consisted of weekly gemcitabine. The patient developed acute gouty attacks after his second dose of gemcitabine, which brought him to the emergency room for emergent treatment on several occasions. Gemcitabine was held and treatment began with fluorouracil and concurrent radiation. After completion of his chemoradiation with fluorouracil, he was again treated with weekly gemcitabine alone. As soon as the patient started gemcitabine chemotherapy the patient developed gouty arthritis again, requiring discontinuation of chemotherapy. The patient received no additional treatment until his recent recurrence 8 months later where gemcitabine chemotherapy was again introduced with prophylactic medications consisting of allopurinol 100 mg by mouth daily and colchicine 0.6 mg by mouth daily throughout gemcitabine chemotherapy, and no signs of gouty arthritis occurred. To our knowledge, this is the first case report describing gout attacks associated with gemcitabine therapy. There is limited data available describing the mechanism that gouty arthritis may be precipitated from gemcitabine chemotherapy. Further monitoring and management may be required in patients receiving gemcitabine chemotherapy with underlying gout.

Blood pressure control in patients receiving bevacizumab in an outpatient cancer center.

PURPOSE: Hypertension is a common adverse effect of vascular endothelial growth factor (VEGF) signaling inhibitors, such as bevacizumab, with an incidence upwards of 35%. The management of bevacizumab-induced hypertension is important in order to avoid dose interruption/discontinuation and/or end organ damage. The efficacy of antihypertensive medications for this cause of hypertension has not been demonstrated. This study seeks to determine if antihypertensives are effective in treating anti-VEGF-induced hypertension from bevacizumab and determine which classes of antihypertensive agents are effective. METHODS: A retrospective review of all patients who received bevacizumab between January 2007 and September 2009 at two medical centers was conducted. Patients were included if they experienced new onset or exacerbation of preexisting hypertension, during bevacizumab treatment. Efficacy of antihypertensives was determined by recording a 28-day change in systolic blood pressure from the initiation or dose increase of individual antihypertensive medications. Secondary endpoints included an efficacy analysis of antihypertensive classes. RESULTS: Five-hundred thirteen patients were identified as receiving bevacizumab during the indicated time period. Fifty-seven patients met the full inclusion/exclusion criteria for analysis. The average systolic blood pressure declined by 23 mm Hg with 4 weeks of treatment (p < 0.0001). Each class had a statistically significant decline in systolic blood pressure of 15.5-57 mm Hg with the exception of diuretics and a group of miscellaneous antihypertensives. CONCLUSIONS: This is the first data that demonstrates individual classes of antihypertensives are effective in bevacizumab-induced hypertension. Most antihypertensives were effective in reducing blood pressure, with the exception of diuretics and miscellaneous antihypertensives, which may be due to a limited sample size.