There is a general impression that medicine is constantly changing. In fact medicine is very conservative and change which challenges conventional thinking (as against using new drugs) can take a long time to be adopted.

One major change though may be upon us. A landmark study in the Journal of The American Medical Association (JAMA) has shown that for at least 20% of women with breast cancer, removal all the axillary (under arm) lymph nodes does not improve survival.

The study, which started in 1999 recruited women with stage T1 and T2 cancers of less than two inches size. All women had what is called sentinel node testing done. This is where a few nodes are removed and analyzed in the pathology lab whilst the patient is still on the operating table. Traditionally if the nodes are positive for cancer cells all the nodes are removed. In this study half the women had the nodes removed whilst the other half did not. All women underwent a form of chemotherapy.

Enrollment was done across 115 sites and continued till 2004. Over the years to 2009 it was found that survival was the same in both groups. Removing all the lymph nodes did not improve survival. However removing all the nodes can lead to a higher rate of post operative complications. Lymphoedema whilst not fatal is an unpleasant condition for which there is little effective treatment.

This is a significant result. It has always been assumed that removing cancer wherever it is found is beneficial. So much so that some doctors refused to be part of the study regarding it as unethical. Early reaction, according to the New York Times suggests changing practice will take some effort.

Breast cancer rates in Austalia more than doubled between 1982 and 2007 to over 12,000 cases annually. In the USA there are around 200,000 cases per year. On the plus side survival has been increasing with five-year survival in Australia going from 72% to 88% over the same 25-year period as above.

Some of this is due to earlier detection. Some is due to improved treatment. Some may be due to the fact that, not all cancers we find will prove fatal. In other words some of the early cancers found may not have developed even if they had not been treated. At this stage we know that is likely the case, but not in whom it will be the case.

We also know (although it is not widely promoted) that there are ways of significantly reducing the chances of getting breast cancer. Regular exercise, moderating alcohol intake and consuming less calories reduces the risk of breast cancer by one third. In contrast screening mammography reduces the risk by about 0.06%. In addition many women will have unnecessary procedures to rule out cancer that was not ever there.

This does not make mammography unhelpful but it is not the only way to reduce breast cancer and its benefits are overstated – usually by those involved in mammography.

Given the nature of our  “health” systems’ findings, which mean fewer complications and less treatment for the same result, this should be welcomed by consumers, doctors and, dare I say, governments.

We need more awareness of ways to genuinely reduce the rate of breast (and other) cancers. We need treatment that provides the best outcome with the least adverse effects and not assume that more treatment always equals better treatment.

The axillary dissection study is a major step forwards in our knowledge. The findings will hopefully be applied sooner rather than later.