Research this week finds that people with severe cancer weight loss get less benefit from fentanyl pain patches and explores why people with Down Syndrome have less cancer.
In other headlines, shut-down of a Canadian nuclear reactor threatens the supply of medical isotopes used in many cancer tests. Free drug samples may do more harm than good, and CT colonography finds cancers and other serious conditions outside the colon in about 2 or 3 out of 100 tests. Finally, we provide a link to a Cancer.Net podcast with information about what to expect from your colonoscopy.
- Patients with cancer cachexia or loss of weight, muscle mass, and fat due to cancer had lower blood levels of fentanyl two and three days into using a fentanyl patch for pain management than did normal weight patients. Cachectic patients had significantly thinner upper arm folds with less fat but there was no difference in local blood flow, sweating, or skin temperature. Pain clinic researchers in Helsinki concluded that, “Absorption of transdermal fentanyl is impaired in cachectic patients compared with that of normal weight cancer pain patients.” Tarji Heiskan and team reported their research in Pain online May 13, 2009.
- People with Down Syndrome are rarely diagnosed with solid tumor cancers, and researchers at Children’s Hospital in Boston have found a reason. Children with Down Syndrome are born with an extra copy of chromosome 21, and additional protein controlled by an extra DSCR1 gene acts within cells themselves to suppress VEGF (vascular endothelial growth factor) preventing potential cancers from developing the blood supply they need to grow and spread. Both cell and mouse studies confirm the activity of DSCR1 proteins to block angiogenesis. The discovery is reported in a letter from lead author to the journal Nature published online May 20, 2009. More detailed information about the study is available from Science Daily, May 21, 2009.
- The shut-down of a Canadian nuclear reactor in Chalk River, Ontario to repair leaking heavy water has imperiled millions of medical imaging tests in the United States. The reactor supplies the radioactive isotope molybdenum-99, injected into patients during nuclear medicine studies. The Canadian reactor is one of only five worldwide that produce medical isotopes, and it provides them for half of hospitals and clinics in the United States. Nuclear medicine experts predict that costs will rise, patients will have to be switched to less accurate testing, and some patients will not be able to have testing at all. The reactor closure is expected to last at least a month and probably longer. Julie Steenhuysen has written about the reactor problems on Reuters Health.
- Health policy researchers Susan Chimonas and Jerome P. Kassirer discuss the negative impact of free drug samples in an essay on PLoS Medicine. They review research that shows only a third of samples go to low-income patients and patients in the highest income categories were most likely to receive free samples. Many samples are diverted for personal use by health professionals. Low-income patients given starter packs of medicines frequently do not fill prescriptions to continue them and have no oversight by a pharmacist. Samples raise the cost of health care with patients who receive them having higher out-of-pocket costs than those who don’t. Estimates are that free samples are worth about $16 billion retail dollars annually in the US. The complete essay by Chimonas and Kassirir is available on PLoS Medicine, published May 12, 2009.
- CT colonography can find cancers outside of the colon. In fact, in a study of over 10,000 people who were screened with CTC, 38 non-colorectal cancers were discovered — more than the 21 colorectal cancers. Most were in the kidney, but lung cancer and lymphomas were also found. Such discoveries are rare. Dr. Perry Pickhardt, discussing them at the 2009 International Symposium on Multidetector-Row CT, pointed out that they occur about once in every 300 CTC procedures. In addition, other serious medical conditions can be seen including unsuspected abdominal aneuryms. However, while a suspicious problem occurs in about 1 out of 10 CTC exams, only 2 or 3 of them will actually be something serious needing treatment.
- Wonder what happens during a colonoscopy? Cancer.Net, the patient and consumer information web site of the American Society of Clinical Oncology, has a podcast that can help. Colonoscopy — What to Expect.