Data from a new study point to an alarming pattern in breast cancer treatment: more than 50% of women with early-stage breast cancer have not received their full, recommended dose of potentially life-saving chemotherapy.

A comprehensive retrospective analysis showed that 56% of the almost 20,800 women who were being treated for cancer in 1,243 community-based oncology practices in the U.S. received less than 85% of their recommended dose intensity, as prescribed in the optimal treatment plan, because of delays of at least one week (in 25% of patients) or dose reductions (in 37%). Earlier studies have indicated that receiving less than 85% of the recommended dose intensity can result in lower survival rates for patients.

The primary reason for the chemo­therapy delays is the presence of neutro-penia, a deficiency of white blood cells, which fight infection and which are destroyed by the effects of the chemotherapy. If the white blood cell count falls too low, patients are at increased risk for infection and, consequently, chemotherapy must be delayed until the cells are replenished.

Although white blood cell “boosters,” known as colony-stimulating factors, are available for the treatment of neutro-penia, only 25% of patients received them during chemotherapy.

The researchers noted that these results are particularly disturbing because earlier studies have underscored the importance of maintaining full chemotherapy dose intensity, especially in responsive and potentially curable malignancies, such as early-stage breast cancer. The study also disclosed a tendency of oncologists to lower dose intensity in order to reduce side effects.

Almost two-thirds of patients older than age 65 were less likely to receive the recommended doses, even though studies have shown that elderly patients can benefit from chemotherapy as much as younger patients. African-American women were also more likely to experience delays in treatment because of lower white blood cell counts.

The women in the study ranged in age from 11 to 90, with a mean age of 52.

Interim data from a randomized, multi-center study indicate that darbepoetin alfa (Aranesp®, Amgen) is beneficial in correcting anemia in cancer patients who are not undergoing chemotherapy. The results were presented at the 45th annual meeting of the American Society of Hematology, from December 6-9, 2003 (Abstract No. 1816).

The hemoglobin counts at the baseline examination were 10.1 g/dl in the Aranesp® group and 10.4 g/dl in the control group. After 12 weeks of treatment, the mean change in hemoglobin was 1.9 g/dl for the Aranesp® group and 0.2 g/dl in the controls, who received standard care.
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The FDA has approved a New Drug Application for insoluble Prussian blue capsules (Radiogardase™) to treat people exposed to radiation contamination caused by harmful levels of cesium 137 or thallium. The capsules contain ferric hexacyanoferrate.

The approval of the Radiogardase™ application is part of the FDA’s continuing efforts to provide the American public with medical countermeasures in the event of a terrorist attack.

Radiogardase™ works by increasing the rate of elimination of these substances from the body. For several decades, Prussian blue has been used to enhance the excretion of cesium 137 and thallium from the body into the stool. Contamination with cesium 137 or thallium can occur through various routes, including ingestion, inhalation, or wounds, and can cause serious illness or death when high radiation doses are absorbed and delivered to critical organs. At lower doses, such contamination has been associated with the development of cancer.

Cesium 137 is widely used in industry and to treat certain cancers. Non-radioactive thallium is used in industry and as a rat poison. The radioactive form of thallium (²⁰¹l) is an approved drug for use in medical imaging procedures and is very safe at low doses.
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Contamination by cesium 137 is of particular concern because of its potential use as a component of conventional explosive devices containing radioactive material (“dirty bombs”). Although this radiological dispersal device is not a nuclear bomb, it can spread radioactive material and contaminate people and property.

Possible side effects include constipation and upset stomach. Treatment should begin as soon as possible after exposure to radioactive cesium or thallium. When the sources of radiation contamination are multiple or unknown, other drugs (such as potassium iodide) can be used together with Radio-gardase™.)

The FDA has approved Rexin-G™ (Epeius Biotechnologies), the world’s first tumor-targeted injectable gene therapy vector, as an orphan drug for pancreatic cancer.

Epeius has executed a screening agree ment with the National Cancer Institute to study the drug. The goal is to develop and commercialize the first effective targeted delivery system that can be injected directly into a vein to deliver genes and molecular therapeutics, preferentially, to cancerous tumors that have spread throughout the body without eliciting systemic side effects or organ damage.

Rexin-G™ is the first targeted inject-able gene therapy vector that has been approved by both the U.S. FDA and the Philippine FDA counterpart for use in phase I and II cancer clinical trials.

The FDA and Genentech, Inc., have issued an important warning to health care providers about bevacizumab (Avastin™) in relation to an increased risk of cerebrovascular accidents, myocardial infarctions, transient ischemic attacks, and angina. The risk of fatal arterial thrombotic events is also increased.

In studies of patients with metastatic colorectal cancer, the risk of a serious arterial thrombotic event was approximately two-fold higher in patients receiving infusional 5-fluorouracil-based chemotherapy plus the bevacizumab.

A revised package insert with more details on arterial thromboembolic events is under development.

Aspirin, often used to help prevent heart attacks and strokes, also appears to reduce the risk of the most common type of breast cancer— that is, tumors whose growth was fueled by estrogen or progesterone. Approximately 70% of women with breast cancer have the hormone receptor-positive type.

The women who used aspirin at least four times a week for at least three months were almost 30% less likely to develop hormone-related breast cancer than women who used no aspirin. Aspirin had no effect on the risk for hormone receptor-negative tumors.

Researchers believe that aspirin works by interfering with the body’s production of estrogen.

Many studies have relied on subjects’ recollections of how often they took aspirin. A more rigorous study has linked the use of low-dose aspirin and a reduced risk of growths that can eventually turn into colon cancer. That study involved randomly assigning patients to take aspirin or placebos, the gold-standard method.

For now, it is not recommended that all women take aspirin, because it can cause side effects such as stomach bleeding. Although the findings are exciting, more research is needed before doctors recommend aspirin to prevent breast cancer.

Sure to be controversial is a plan to give promising new cancer drugs to some patients in clinical trials and to give placebos to other patients.

Some cancer researchers strongly oppose the use of placebos. Placebo trials have not generally been used in life-threatening diseases such as cancer, because it has been considered unethical to give placebos when any kind of effective therapy might be available. However, some companies, including Bayer, Pfizer, and Genentech, are adding placebo arms to their trials in an effort to speed promising new drugs to market. Because placebo trials make it easier to verify results, the strategy can reduce the need for additional studies and lead to faster regulatory approval.

Many in the cancer community maintain that this approach denies desperately ill people a last best hope. The M.D. Anderson Cancer Center in Houston and the University of Michigan Cancer Center in Ann Arbor have refused to put patients in clinical trials that use placebos. Patient-advocacy groups have urged companies to change their minds about running trials with placebo arms.

It has become difficult to get patients to participate in cancer-drug studies in the first place. One reason is that patients fear getting a placebo; patients receiving placebos have died sooner than those receiving drug therapy.

Some pharmaceutical companies say that the very nature of these new cancer drugs makes it imperative to have a placebo arm for comparison. Unlike traditional chemotherapy, which is designed to shrink or eradicate tumors, many of these drugs aim to stop or slow tumors’ growth and allow some patients to live with their cancer. This makes it difficult to measure whether it is the drug that is working or whether the tumor is simply less aggressive.