A bone cancer survival rate refers to the percentage of people who were reported still living after being diagnosed with the cancer about 5 yrs ago. In reality, this type of cancer is very rare. In fact, it's so rare than it only consists of about 1% among all tumor cases. Bone tumors, unlike most other types of cancer tumors, are not all fatal or cancerous. Benign tumors are even more prevalent than malignant tumors, which may be a much more relieving news for many. EzineArticles.com
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Researchers used a harmless virus to smuggle DNA into the body.
We’ve previously written about immunotherapy– treatments that use the power of a patient’s own immune system to attack their disease.
On paper, immunotherapy looks like a sure-fire way to treat cancer – simply ‘train’ a patient’s immune system to recognise and destroy tumour cells, and nature will do the rest. However, clinical trials of various immunotherapy techniques have shown only modest benefits, with one or two high-profile exceptions.
But a paper from Cancer Research UK scientists and their UK and US colleagues, published in this week’s edition of the journal Nature Medicine, describes a completely new approach that could make a big difference to immunotherapy in the future.
In this case, the team used the technique to treat prostate cancer in mice, but it’s likely that the same technology could be applied to other types of cancer.
Here’s a short interview with one of the paper’s authors, Professor Alan Melcher from the Cancer Research UK Clinical Centre in Leeds, explaining more about the new results:
Link to transcript
Creating cancer vaccines
At the moment, most immunotherapy techniques work by teaching a patient’s immune system to recognise certain individual molecules found in cancer cells.
One way of doing this is to use a therapeutic cancer vaccine. Unlike prophylactic vaccines, which prevent you from getting an illness in the first place (such as those given to children or people travelling abroad), cancer vaccines are designed to stimulate a patient’s immune system to seek out and destroy cancerous cells, wherever they may be hiding.
There are several ways of doing this, but Professor Melcher and his colleagues are focusing on DNA vaccines, where a patient is injected with DNA containing the instructions telling cells to make a harmless protein found in cancer cells.
The patient then produces this protein in their body, and their immune system recognises it and starts making antibodies that attack it. But because the protein also exists in cancer cells, the immune system hunts them down too.
What’s so special about this new technique?
Most DNA cancer vaccines train the immune system to recognise either one or just a handful of proteins. But if the patient’s cancer cells aren’t producing any of them, then the vaccine won’t work – a problem for producing a vaccine that’s suitable for large numbers of cancer patients.
To get round this problem, Professor Melcher and his colleagues tried a different approach. Rather than making a vaccine out of DNA instructions for making just one or two proteins, they used thousands.
The researchers started with thousands of DNA fragments taken from normal prostate tissue, each of which was capable of making a single protein. To turn these fragments into a vaccine, the researchers packaged each of them up into a harmless virus called vesicular stomatitis virus (VSV).
Other researchers are currently developing VSV for use as a treatment for cancer, and similar viruses have already been tested in clinical trials, suggesting that it’s safe for use in patients – a head start for any potential treatment.
VSV is a handy way of smuggling DNA into the body, because it tends to infect cancer cells in preference to healthy tissue. And because the immune system is, under most circumstances, very good at recognising and attacking virus-infected cells, this increases the chances that it will be stimulated by the unusual DNA to go on the hunt for cancer cells.
Testing it out
First, the scientists needed to make sure their virus-based vaccine wouldn’t cause the immune system to start attacking healthy prostate tissue – something that would obviously be a bad thing for a potential cancer treatment.
The researchers vaccinated healthy mice and monitored the size of the animals’ prostates over time. Although initially they saw an increase in prostate size, after several weeks they were the same as prostate glands from untreated animals, suggesting that there wasn’t a major immune response against healthy cells.
Next, they treated mice with prostate cancer with the modified virus and found that they survived longer than mice given normal, unmodified viruses. And after nine injections of the DNA-packed virus, eight out of ten animals were cured.
The scientists also discovered that viruses packed with DNA from prostate cells didn’t work against skin tumours, showing that the DNA needs to come from the same tissue as the cancer to be effective.
Targeting recurring tumours
Although the vaccine was effective in treating 80 per cent of tumours, this means that it didn’t work for around 20 per cent of cases – in these instances, although the cancers initially shrank, the scientists found that they came back and grew aggressively.
To tackle this problem, the researchers generated a collection of DNA fragments from these resistant tumours, and put it into VSV viruses. Then they treated mice with prostate tumours first with the virus containing DNA from normal prostate, then with VSV carrying DNA from the recurrent tumours.
The researchers discovered that the tumours recurred much more slowly in mice given the combination of vaccines than those given the normal DNA vaccine alone. And in some cases, the tumours never came back.
What does this mean for cancer patients?
Right now, this vaccine is a long way from being suitable for use in patients with prostate or any other type of cancer. More tests need to be done to confirm that the treatment is safe and effective.
For a start, the scientists don’t know exactly what sort of DNA would work best to stimulate the human immune system. And although the treatment didn’t cause big problems with the immune system attacking healthy tissue in mice, that’s no guarantee it won’t happen in humans.
But given those caveats, this is certainly an exciting piece of research that could change the direction of immunotherapy. Perhaps one day we’ll see ‘off the shelf’ DNA vaccines for many different types of cancer, generated using an approach like this.
We’ll be watching to see how this story develops over the coming years, and hope that it will soon translate into clinical trials and – ultimately – benefits for patients.
Kat
The excellent NHS Choices blog has covered this story in more detail http://www.nhs.uk/news/2011/06June/Pages/vaccine-against-prostate-cancer.aspx
Image courtesy of Wikimedia Commons
Reference
Kottke T et al (2011). Broad antigenic coverage induced by vaccination with virus-based cDNA libraries cures established tumors. Nature medicine PMID: 21685898
Filed under: Cancer Research UK-funded research, Cancer Treatment, Immune system, Immunotherapy, Prostate, Science, Scientific papers scienceblog.cancerresearchuk.org
Among women with a history of non-melanoma skin cancer (such as basal cell carcinoma or squamous cell carcinoma), vitamin D and calcium supplements may reduce the risk of melanoma. These results were published in the Journal of Clinical Oncology.
Of the more than one million new diagnoses of skin cancer each year, roughly 68,000 involve melanoma. More than 8,000 people die of melanoma each year in the United States. What makes melanoma so dangerous is that it is more likely than other types of skin cancer to spread (metastasize) to other parts of the body.
Although advances have been made in melanoma treatment, the disease continues to be challenging to control. As a result, prevention of melanoma remains an important goal.
Vitamin D is important for bone health, and some research suggests that it may also reduce the risk of certain types of cancer. A role for vitamin D in cancer prevention has not yet been firmly established, however, and research on this topic continues. Vitamin D can be produced in the skin in response to ultraviolet B (UVB) radiation from the sun or obtained from dietary sources. Few foods naturally contain large amount of vitamin D, but vitamin D can be obtained from fatty fish such as salmon, fortified foods such as milk, and dietary supplements.
To explore the relationship between vitamin D and skin cancer, researchers evaluated information from Women’s Health Initiative trial of calcium and vitamin D.[1] The trial enrolled roughly 36,000 women between the ages of 50 and 79.
Study participants took either daily calcium and vitamin D supplements (with a daily dose of 1,000 mg of elemental calcium and 400 IU of vitamin D3) or placebos. Previous reports from this study indicated that calcium and vitamin D supplementation did not reduce the risk of colorectal cancer[2] or breast cancer.[3] The current report focused on both melanoma and non-melanoma skin cancer.
Overall, calcium and vitamin D supplementation did not affect the risk of melanoma or non-melanoma skin cancer.
In the subgroup of women with a history of non-melanoma skin cancer, those in the vitamin D and calcium group had a 57% reduction in risk of melanoma. There were 10 melanoma cases in the calcium and vitamin D group and 24 cases in the placebo group.
These results suggest that vitamin D and calcium supplementation may reduce the risk of melanoma in women with a history of non-melanoma skin cancer. Subgroup analyses such as this one can be prone to bias, however, and these results cannot be viewed as definitive. The lead researcher on the study is planning to conduct additional studies on vitamin D and cancer prevention.
Talk with your healthcare provider if you have questions about your vitamin D status or need for additional vitamin D. In addition, keep in mind that although sun exposure can produce high levels of vitamin D, organizations such as the American Academy of Dermatology do not recommend sun exposure as a source of vitamin D because of the link between sun exposure and skin cancer. Dietary supplements can provide an identical form of vitamin D without the skin cancer risk.
References:
[1] Tang JY, Fu T, LeBlanc E et al. Calcium plus vitamin D supplementation and the risk of nonmelanoma and melanoma skin cancer: post hoc analyses of the Women’s Health Initiative Randomized Controlled Trial. Journal of Clinical Oncology. Early online publication June 27, 2011
[2] Wactawski-Wende J, Kotchen JM, Anderson GL, et al: Calcium plus vitamin D supplementation and the risk of colorectal cancer. New England Journal of Medicine. 2006;354:684-696.
[3] Chlebowski RT, Johnson KC, Kooperberg C, et al: Calcium plus vitamin D supplementation and the risk of breast cancer. Journal of the National Cancer Institute. 2008;100:1581-1591. news.cancerconnect.com
Exercise is linked with longer survival for patients with advanced glioma, a form of brain cancer. These findings were recently reported in the Journal of Clinical Oncology.
Gliomas are brain tumors that arise from glial cells (cells that provide a supportive function in the brain). Depending on their characteristics, gliomas may be classified as low-grade (less aggressive) or high-grade (more aggressive).
Exercise and its relationship to patient quality of life, cancer prevention, and impact on treatment and recurrence have been studied extensively in several types of cancer. Regular physical activity may help improve overall health and well-being as well as treatment outcomes.
Researchers with the Duke Cancer Institute recently conducted a study designed to identify key indicators of prognosis among patients with malignant recurrent glioma. The study included 243 patients with this form of brain cancer. Participants reported their levels of physical activity. At a median follow-up of just over 27 months, 149 patients (61% of participants) had died.
Survival was extended significantly among patients who reported regular, brisk exercise. These patients lived a median of almost 22 months compared with about 13 months for sedentary patients.
Exercise was linked with survival independently of other prognostic factors (such as age, gender, and disease history).
The researchers conclude that information about a patient’s exercise habits can help doctors predict long-term outcome for patients with advanced glioma. They explain that accurate prognoses can help doctors create more-appropriate treatment plans.
Reference: Ruden E, Reardon DA, Coan AD, et al. Exercise, behavior, functional capacity, and survival in adults with recurrent malignant glioma. Journal of Clinical Oncology [early online publication]. June 20, 2011. news.cancerconnect.com
Using a newly developed drug screen, researchers have discovered small molecule compounds that are able to perform the functions of a gene commonly mutated in many types of cancer. By combining molecular imaging techniques with human cancer cell culture and animal model approaches, the researchers were able to reveal the ability of the compounds to kill human tumor cells. These findings emphasize the growing role of imaging technology in aiding researchers in the development of individualized cancer treatments. www.uphs.upenn.edu
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