New Scientist cancer special

The latest issue of New Scientist is a cancer special titled 'Old killer, new hope'.

The main focus of the issue is a large article on genomics - 'Living with the enemy'. Instead of classifying tumors according to where in the body they appear, for example the prostate or the lung, scientists are now starting to groups cancers according to which molecular pathway the cancer uses in order to grow and spread.

New targeted therapies can act specifically on a particular molecular pathway, sparing the normal dividing cells that are often killed off in conventional forms of cancer therapy. For example, breast cancer patients with mutations that cause overproduction of the protein HER2 can be treated specifically with with an antibody called trastuzumab, better known as Herceptin, whereas those with receptors to the hormone estrogen can be treated with a drug called tamoxifen. An interactive graphic shows how these modern therapies work.

'Patients doing it for themselves' describes how powerful, well-funded patient groups are setting the agenda for cancer research. The article cites the example of the Multiple Myeloma Research Foundation, which amazingly donates as much money to research on multiple myeloma as the US National Cancer Institute.

The capacity of the immune system to hold tumors dormant is discussed in 'Tumors under lock and key'. Apparently about a third of breast cancer survivors still have tumor cells circulating in their blood after successful treatment, in cases up to 22 years after therapy. Finding out how the immune system keeps microtumors, which are thought to be responsible for these circulating tumor cells, from running amok could provide new strategies for fighting cancer.

The special issue also contains a list of expert tips for evading cancer and an editorial lamenting how patients and healthcare providers are ever going to be able to afford these fancy new treatments.

All these articles are currently available online for free, so go check them out.

Attitude has no effect on survival in women with breast cancer

Many patients with cancer feel that their attitude towards the 'fight' is an important part of beating the disease, but maintaining a positive perspective is pretty tough in the face of a life-threatening malignancy.

A large, population-based study published in the Journal of Clinical Oncology has now found that psychosocial factors such as fighting spirit and fatalism have no effect on survival in patients with breast cancer. The authors Phillips et al. emphasize that their results could allay the concerns of anxious women who believe that their mental attitude towards breast cancer will affect their likelihood of survival, and could in fact lift the burden of responsibility such women may feel.

Phillips et al. studied 708 Australian women diagnosed with nonmetastatic breast cancer before the age of 60 (average age 40 years old). At study entry approximately 11 months after diagnosis, all women completed an array of psychosocial tests that were designed to assess factors such as anxiety and depression, coping style, and social support. These women were then followed up for an average of 8.2 years.

In total, 33% of women experienced distant recurrence of their cancer and 24% died during follow-up. Once the patient data had been adjusted to take into account other factors that affect chances of recovery, such as tumour size, no associations could be found between psychosocial factors and either distant disease-free survival or overall survival.

The authors conclude that their study does not support the controversial theory that psychosocial factors influence survival after breast cancer. They state, "This should be reassuring for women, particularly those who experience substantial levels of psychosocial distress after their diagnosis."

It is important to note, however, that therapies that aim to reduce psychosocial stress in women with breast cancer should not be discounted, as such interventions do seem to improve quality of life.

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K.-A. Phillips, R. H. Osborne, G. G. Giles, G. S. Dite, C. Apicella, J. L. Hopper, R. L. Milne (2008). Psychosocial Factors and Survival of Young Women With Breast Cancer: A Population-Based Prospective Cohort Study. Journal of Clinical Oncology 26 (28): 4666-4671 DOI: 10.1200/JCO.2007.14.8718

Do common pain medications mask signs of prostate cancer?

A study recently published in the journal Cancer has suggested that common painkillers such as paracetamol and aspirin might affect blood levels of a marker commonly used to diagnose prostate cancer.

In this study, Singer et al. examined levels of prostate specific antigen (PSA) in the bloodstream of 1,319 men aged over 40 years. PSA is a protein produced in the prostate gland. Blood levels of PSA will be minuscule in healthy men, but raised levels often indicate the presence of prostate cancer. If a simple blood test detects serum levels of PSA higher than a specific threshold (4 ng/ml to be exact), your doctor will be booking you in for a digital rectal examination with a prostate cancer specialist faster than you can say "He wants to stick his finger where?!"

In addition, study participants were asked how often they took analgesic drugs classed as non-steroidal anti-inflammatory drugs (NSAIDs) - common types being aspirin and ibuprofen - or the drug acetaminophen, which you'll probably be familiar with as paracetamol. NSAIDs and acetaminophen act as painkillers by reducing inflammation. Given that inflammation in the prostate has been implicated in the development of prostate cancer, the authors of this study wanted to find out whether NSAIDs or acetaminophen affected the risk of prostate cancer in men who took these drugs.

The results of this study showed that serum levels of PSA in men who took NSAIDs or acetaminophen "nearly every day" were considerably lower than levels in men who did not take either drug. Seeing as this study didn't then follow these men for several years to find out whether there were fewer instances of prostate cancer in the men who took these analgesics than in those who didn't, it is not clear whether this decrease in PSA levels means that the drugs reduce the risk of cancer. In fact, it it possible that NSAIDs and acetaminophen may reduce serum levels of PSA despite suspicious goings on in the prostate and thus cause doctors to miss cases of prostate cancer, which would otherwise be flagged by raised PSA levels.

So what are the implications of the study? Should men chew down aspirin every day to prevent prostate cancer, or would they make detection of the malignancy more difficult for their doctor by doing so? Dr Eric Singer, one of the authors of this study, told Reuters news, "If you're a guy who's close to the upper limit of normal [in PSA levels] or would have been over the upper limit and now you're under it because of [these drugs], that could certainly change whether or not you would be referred for a biopsy [to check for a tumor]". He also emphasizes that these findings are preliminary and shouldn't prompt men to change their behaviour.

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Eric A. Singer, Ganesh S. Palapattu, Edwin van Wijngaarden (2008). Prostate-specific antigen levels in relation to consumption of nonsteroidal anti-inflammatory drugs and acetaminophen Cancer DOI: 10.1002/cncr.23806