Friday, September 04, 2009

Cancer Carnival #25

Welcome to the 25th edition of the Cancer Research Blog Carnival - your monthly roundup of cancer related blogging.

Unless you've been cut off from all news, you're probably aware of the debate over health care reform happening in the United States. Sandy Ordonez has sent us this overview, which includes interviews with doctors and insurance providers.

Cancer, of course, doesn't care if you're rich, poor, uninsured or where you're from. The Viewspaper looks at the issue of cancer in India - much of which is tobacco related - as well as their own National Cancer Control Programme.

Erin Cline Davis, from the 23andMe blog The Spittoon, keeps us up to date with the latest SNPs associated with cancer, this time genetic variants associated with childhood ALL.

Fred Lee from Healthcare Hacks discusses a recent study from the Journal of the American Medical Association that looked at the effects of aspirin on cancer survival.
In addition to lessening pain while also helping to prevent heart attacks and strokes, aspirin is now believed to increase the chance of survival for patients suffering from colon cancer. In fact, a recent study published in the Journal of the American Medical Association (JAMA) found that colon cancer patients reduced their risk of dying from the disease by as much as 30% when they took aspirin in conjunction with surgery and chemotherapy.
The effect is only effective with tumours that overexpress Cox-2. The mechanism of action is still unclear - other Cox-2 inhibitors have been tested, such as celecoxib (Celebrex), and they have effects in vitro even when Cox-2 inhibition is removed.

Fred continues with his healthcare hacks, describing a NEJM study that shows that weightlifting may alleviate one of the possible side-effects of breast cancer treatment, lymphedema.
Though the idea has been argued for years, this is the first study with the size, scope and duration to give it clinical relevancy to the notion that not only is exercise not bad for breast cancer survivors, but that it might be beneficial, as well. Breast cancer survivors who were suffering from lymphedema were divided into two sections: one group was told not to change their exercise habits, while the other took part in a 90 minute weightlifting class twice a week for 13 weeks. After the classes, the subjects worked out on their own for an additional 39 weeks.
This runs contrary to past recommendations to avoid strain, such as heavy lifting, on the affected areas.

We have another double-hit of submissions from Kat Arney who blogs for Cancer Research UK. First, she demystifies recent claims that we're "2-years from a cure for breast cancer", explaining the science behind estrogen receptor regulated microRNAs and why the recent findings are still a long way from a cure.
Dr Stebbing’s results help to unravel the complex communications circuits within cells that controls the activity of our genes, and helps to explain how this goes wrong in cancer. Now we know more about this, we can start to look for potential treatments.

One speculative idea might be to add extra processed miRNAs to breast cancer cells, to switch off the oestrogen receptor so the cells stop growing – but this needs to be explored in further experiments.
Dr. Arney also directs our attention to the BRAF gene, which is defective in 70% of melanomas, in an ongoing series focusing on Cancer Research UK-funded work
One of the key players in certain signalling cascades is BRAF, a protein produced from the instructions carried by the BRAF gene. BRAF is a kinase, a protein that sticks chemical ‘tags’ onto other proteins, activating them in order to pass on signals in the cell. And, as you might expect, faults in BRAF can have big implications for cells – and for cancer.
Here at the Bayblab, Bayman discusses transmissible tumours in tasmanian devils, raising some questions about tumour immunology and the effectiveness of cancer vaccines. Among the issues raised: why, if tumours are effective at evading the immune system, aren't more tumours transmissible? Ian York at Mystery Rays from Outer Space tries to answer that question.
The most important factor, I suspect, has nothing to do with immunology. These tumors are unusual in that they have a built-in way of contacting new hosts. TDFT is spread through bites, CTVT is spread sexually. There’s no similar way that, say, a liver tumor, or a brain tumor, could be spread. So that immediately rules out the vast majority of tumors; even if they could survive after transmission, there’s no chance of a transmission chain. But still, most tumors would be rejected even if they did manage to be transmitted.
The posts and comments across both blogs are interesting and worth the read. Ian continues his posts about transmissible tumours by looking at a human case: the vertical transmission of tumours from mother to fetus.
Malignancy during pregnancy isn’t all that uncommon (0.1% of pregnancies, it says here), so the handful of cases with actual spread of the tumor to the fetus are “numerically inconsequential”. What was different about these 14 cases? We don’t really know, in general. Almost all of the described cases are earlier than 1965, predating the molecular era of medicine.
Another interesting case of transmissible tumour, even if the mechanism of immune evasion isn't clear. But as he points out, "these stories are still worth keeping in mind when thinking about tumour transmission" (and tumour immunology).

That's it for this month's Cancer Research Blog Carnival. For older editions, visit the Carnival Homepage. Don't forget, the CRBC has subscription options; you can follow by email or RSS feed. An aggregated feed of credible, rotating health and medicine blog carnivals is also available.

If you'd like to host a future edition, email


Anonymous Coward said...

Wow a lot of good stories. I love that Kat Arney somehow made her way to our blog, she was the incredibly sexy voice of the naked scientist podcast. I don't listen to it anymore, but they were a pretty funny duo.