Colorectal Cancer Biomarkers in the Era of Personalized Medicine.

The 5-year survival probability for patients with metastatic colorectal cancer has not drastically changed over the last several years, nor has the backbone chemotherapy in first-line disease. Nevertheless, newer targeted therapies and immunotherapies have been approved primarily in the refractory setting, which appears to benefit a small proportion of patients. Until recently, rat sarcoma (RAS) mutations remained the only genomic biomarker to assist with therapy selection in metastatic colorectal cancer. Next generation sequencing has unveiled many more potentially powerful predictive genomic markers of therapy response. Importantly, there are also clinical and physiologic predictive or prognostic biomarkers, such as tumor sidedness. Variations in germline pharmacogenomic biomarkers have demonstrated usefulness in determining response or risk of toxicity, which can be critical in defining dose intensity. This review outlines such biomarkers and summarizes their clinical implications on the treatment of colorectal cancer. It is critical that clinicians understand which biomarkers are clinically validated for use in practice and how to act on such test results.

Octreotide and Lanreotide in Gastroenteropancreatic Neuroendocrine Tumors.

Neuroendocrine tumors are heterogeneous, rare malignancies that arise most commonly in the gastrointestinal tract and pancreas. They often secrete vasoactive substances resulting in carcinoid syndrome and the tumor cells exclusively express somatostatin receptors. Octreotide and lanreotide are the two synthetic somatostatin analogs used for the control of carcinoid symptoms and tumor progression in advanced inoperable disease. Recent pivotal trials (PROMID and CLARINET studies) established their antitumor activity. We discuss the available data to support their use as symptom controlling and antiproliferative agents. This article also reviews the guidelines (National Comprehensive Cancer Network and North American Neuro Endocrine Tumor Society), cost-analysis (suggesting the cost-effectiveness of lanreotide autogel compared to higher doses of octreotide long acting release formulation in refractory patients), and future directions of somatostatin analogs in the management of patients refractory to conventional doses of octreotide and lanreotide.

Management of hyperglycemia from epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) targeting T790M-mediated resistance.

Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients are associated with sensitivity to small molecule tyrosine kinase inhibitors (TKIs) such as erlotinib, gefitinib, and afatinib. Although studies show an increased progression free survival (PFS) with use of EGFR TKIs in the first-line setting, most patients will develop resistance to therapy after the first 8-16 months. T790M is an acquired resistance mutation reported in 60-70% of patients who initially responded to a prior EGFR TKI. Recently, EGFR TKIs targeting T790M have been developed to overcome resistance with positive results in PFS and objective response rate in patients who have had disease progression on at least one TKI. Two EGFR TKIs targeting T790M, AZD9291 and rociletinib, are new active treatment options for NSCLC but differ in adverse effect profiles. Dose-limiting hyperglycemia has been reported with rociletinib and has required dose reduction, an oral antihyperglycemic, or both, without discontinuation of therapy. This suggests that patients may be effectively treated chronically for hyperglycemia associated with EGFR TKIs targeting T790M, however, guidelines for treatment of hyperglycemia in this setting have not been published. We discuss mechanisms of hyperglycemia associated with TKIs and initial management of hyperglycemia, including benefits and limitations of oral antihyperglycemic options, adjustment of therapy based on grade of hyperglycemia, and recommendations for follow-up glucose monitoring.

Clinical use of abiraterone in the treatment of metastatic castration-resistant prostate cancer.

Prostate cancer remains the most common type of cancer among men in the United States. Treatment for metastatic prostate cancer has improved significantly over the years with more and more agents improving overall survival. This review will address the pathophysiology of prostate cancer followed by the mechanism of action and the pharmacokinetic properties of abiraterone. The review will also discuss the role of abiraterone in the treatment of metastatic castrate-resistant prostate cancer.

Carboplatin pharmacokinetics in a patient receiving hemodialysis.

With refinements and advances in hemodialysis techniques, survival for patients with end-stage renal disease has improved significantly. To our knowledge, however, no prospective trials have been performed in patients receiving hemodialysis who are also diagnosed with cancer and are candidates for chemotherapy. We describe a 73-year-old man who was diagnosed with high-grade neuroendocrine carcinoma, metastatic to the bone and lymph nodes, and was undergoing hemodialysis. Although cisplatin is more commonly used in the treatment of metastatic neuroendocrine cancers, it may not be the best option in patients who suffer from renal insufficiency. Carboplatin is a second-generation, nonnephrotoxic platinum analog that can be hemodialyzed, although no formal guidelines are available regarding the dosing for patients receiving hemodialysis. This case describes a patient who was treated with five cycles of combination carboplatin 115 mg/m(2) on day 1 and etoposide 50 mg/m(2) on day 1 and day 3 of a 28-day cycle. Dialysis was performed for 3.5 hours starting 90 minutes after completion of carboplatin on day 1. Pharmacokinetic assessments were performed at 1, 2, 4, and 12 hours after chemotherapy infusion on day 1 of cycle 1. Total carboplatin concentrations in plasma and platinum ultrafiltrate were measured. The plasma concentration of free platinum at the end of the infusion was 31,000 ng/ml, and the area under the plasma concentration-time curve was 2.9 minute·mg/ml. No significant carboplatin-related toxicities were reported. This case report indicates that carboplatin can be safely administered in patients receiving hemodialysis.

Neoadjuvant chemoradiotherapy for esophageal/gastroesophageal carcinoma.

BACKGROUND: Esophageal/gastroesophageal junction (GEJ) adenocarcinoma is increasingly treated with trimodality therapy. We present our experience using carboplatin/paclitaxel and radiotherapy followed by surgery. METHODS: Consecutive patients with distal esophageal/GEJ adenocarcinoma (≥T2 or N+) treated from July 2010 to October 2011 were identified. Treatment included neoadjuvant carboplatin/paclitaxel with concurrent radiotherapy (CRT) to 50.4 Gy using an IMRT technique and then Ivor Lewis esophagogastrectomy (ILE). PET/CT was performed prior to and after CRT. Patient/treatment characteristics and tumor response were analyzed. RESULTS: Over this timeframe, 16 patients completed trimodality therapy. All were male, median age of 60 years (45-72 years). All tumors were grade 2-3 with mean tumor length of 4.4 cm (1-9 cm). A median of 6 cycles (5-9 cycles) neoadjuvant carboplatin/paclitaxel were administered. Average time from diagnosis to CRT completion was 76 days (44-141 days) and 60 days (35-92 days) from CRT end to surgery. Neoadjuvant CRT was well tolerated with mean weight loss of 3.9 kg. All pts had R0 resections. No anastomotic leaks or perioperative mortality occurred. Mean hospital stay was 13 days (8-28 days). Pathologic complete response (pCR) was seen in 38% of patients, microscopic residual disease (isolated tumor cells or <2 mm) in 31%, and macroscopic residual disease remained in 31%. Mean SUV reduction was 41% (0-100%). Of 11 patients with ≥35% SUV decrease, 45% had pCR and 27% had microscopic residual disease. Three patients had signet ring features. Of these, 2 had no SUV reduction and all had gross residual disease, including the only patient with positive nodal disease. CONCLUSIONS: Trimodality therapy utilizing concurrent carboplatin/paclitaxel and radiotherapy to 50.4 Gy followed by surgery was well tolerated and resulted in significant pathologic complete response or minimal residual disease. Further investigation of predictive factors for response is needed to best tailor therapy in the management of esophageal/GEJ adenocarcinoma.

A new era for castrate resistant prostate cancer: a treatment review and update.

PURPOSE: The purpose of this review article is to present the current treatment options for castrate resistant prostate cancer in addition to the recently approved agents and their role in treatment. SUMMARY: The biology of prostate cancer and the data supporting the use of traditional chemotherapeutic options in castrate resistant prostate cancer are reviewed. The newly approved agents, sipuleucel-T, cabazitaxel, and abiraterone, are presented as well. The studies that led to the approval of these three agents are discussed in this article as well as their current and potential roles in the treatment of castrate resistant prostate cancer. CONCLUSION: New mechanisms, drugs, and clinically relevant molecular targets show survival advantage and are new options available for patients after traditional chemotherapy. The roles of these new agents have yet to be further clarified in future studies.