Findings from a recent study provides preliminary evidence supporting the use of Y90 microspheres for the treatment of neuroendocrine tumors of the pancreas and liver, and suggests that a patient's risk of toxicity is predictive of the likelihood of a response to treatment.
Based on this data, serious problems may be anticipated in the treatment of patients with neuroendocrine tumors. The risk of aggressive tumor behavior, tumor proliferation or regression when new drug therapies arrive in the therapeutic arsenal, must be considered with caution before treatment and carefully followed during therapy.
Many neuroendocrine tumors can be treated with surgical removal (surgery for neuroendocrine tumors of the pancreas or for neuroendocrine tumors of the pancreas and liver) or medical therapies depending on the type of tumor and other factors. Surgical treatment includes liver transplantation for hepatic hormone secreting tumors that cause hepatic dysfunction and resection for tumors that affect portal vein flow or lead to portal hypertension. Many other tumors of neuroendocrine origin do not affect the liver and do not produce any demonstrable endocrine dysfunction. Treatment of these tumors depends on the location of the tumors and in some cases, the extent of disease.
Neuroendocrine tumors may develop from an abnormal cell which releases hormones or which has a mutation that causes the cell to release hormones. Rarely, a new hormone, hormone-like substance, or protein may cause neuroendocrine tumors by stimulating receptor-cells to release hormones.
Approximately 452,600 in the United States will develop a neuroendocrine tumor each year and more than 2,000 of these people will die. The five most common types of neuroendocrine tumor are carcinoid, medullary thyroid, parathyroid, pancreatic, and nonfunctional neuroendocrine tumors.
We found that approximately 2% of newly diagnosed patients with solid tumors, including NSCLC, would be candidates for endocrine therapy. However, as is true for all patients with solid tumors, the determination of which treatment to use is complex owing to the heterogeneity of these neoplasms. Clin Cancer Res; 20(16); 4153-9. ©2014 AACR.
Many signs of neuroendocrine tumors involve the skin, including changes in the hair, nails and eye pigmentation (of course, these may be nonspecific). Symptoms, such as headaches, fatigue and malaise, are also signs of neuroendocrine tumors. A large number of symptoms involve the gastrointestinal system. For the most part, however, the signs of neuroendocrine tumors are nonspecific.
There is only moderate resolution of symptoms from patients treated for carcinoid and medullary thyroid cancer. Larger studies are needed to validate existing data. Patients with metastatic disease have a dismal prognosis; consequently, treatment strategies are mainly palliative.
NE tumor patients at the time of primary diagnosis had a statistically significantly reduced PFS compared to patients with metastatic disease at the time of initiation of treatment with NETS, suggesting that NETs should be treated very cautiously in the metastatic setting.
There has been only one study comparing y-90 to a standard chemotherapeutic and no trials directly comparing y-90 with another type. Therefore, the evidence for it is not conclusive in terms of its safety, effectiveness, and optimum duration of treatment. The patient-to-patient variation in tumor volume, particularly when the tumor is more or less uniformly radiosurgery injected, should be taken in account in comparing Y-90 and other techniques. More data are indicated, including additional patient selection criteria and methods of randomization.
Although no studies have been published, in-frame Y-90 microsphere treatments are often used for several indications. There are no clear published data or case series demonstrating that Y-90 therapy has a therapeutic role in patients with cancer. However there is some evidence that patients with thyroid tumors may respond much better to radiotherapy using Y-90, as compared with other treatments. The efficacy is greater with the application of multiple administrations of injections, while the number of visits may seem high in comparison with other radiotherapeutic procedures.
There is a need to evaluate whether the differences exist between treatment protocols and survival rates. Furthermore, survival statistics related to neuroendocrine tumors should be collected in prospective multicenter studies.