Canadian research shows occupational link to breast cancer

“Certain occupational exposures appear to increase the risk of developing postmenopausal breast cancer”, is a conclusion reached by Canadian researchers and released in April 2010 edition of the Journal of Occupational & Environmental Medicine.

The researchers acknowledged that “some findings might be due to chance or to undetected bias some findings might be due to chance or to undetected bias”, but there is enough evidence to generate concern in occupational sectors and, often, the media shows increased interest in breast cancer research.

Several Australian scientists have advised caution on interpreting the research findings.   Professor Bernard Stewart, Scientific Advisor to Cancer Council Australia, is well aware of the media interest in breast cancer risks,  has said

“This study contributes to, but does not settle, the issue of whether occupational exposure to solvents causes breast cancer.  For example, we know particular workplace exposures have been proven to cause lung, skin and bladder cancer, however any such causation of breast cancer remains in question.  Such investigations are can also be limited by the relatively low range of risk.

While smoking increases lung cancer risk by more than 20-fold, this study suggests breast cancer risk ranges from zero up to a two-fold increase following solvent exposure.  The findings should prompt action, but not anxiety. Implications that breast cancer risk may be greater following early-life exposure warrant follow-up research.

As things stand, there is no clear evidence that reducing solvent exposure can prevent breast cancer.  However, for a range of other health reasons, employers should aim to minimise solvent inhalation in the workplace.”

Professor Chris Winder of the University of New South Wales is more critical of the research

“Malignant breast cancer is unfortunately a common cancer in women, and the range of possible risk factors is large, including occupation.   This new study is useful because it suggests some workplace risk factors, such as exposure to some plastics and polyaromatic hydrocarbons as being associated with breast cancer.   But these results need careful evaluation, as the research methods are imprecise and exposure assessment inexact.  More work is needed to confirm these findings.”

Professor Stewart’s comments reinforce the need for workplaces to  undertake detailed risk assessments if hazardous substances are a required element of the work processes.  Studies that illustrate new consequences for substances that we already know are harmful confirm the need for an appropriate safety management system and illustrate the wisdom of eliminating hazardous substances.

Kevin Jones