There was an interesting paper published recently in The Lancet Oncology, which looked at the increased risk of developing lung cancer after women had experienced prior breast cancer (see ref below).  Over the years, there has been much debate about the potential impact of different treatment regimens, whether chemotherapy or radiotherapy, on the development of secondary cancers, but what about other factors such as lifestyle and health issues?

Yet in many ways, it’s almost a catch 22 situation, because improvements in treatment for breast cancer also means that women are living longer, and therefore at a greater risk of developing a second malignancy with the passage of time.  This study set out to see which variables might possibly be important.  According to the authors:

“We review data on the effect of treatment factors (ie, surgery type, radiotherapy technique, and adjuvant chemotherapy) and patient factors (ie, age and smoking) on the risk of developing a subsequent lung cancer.”

The results suggested that:

“Older radiotherapy techniques were associated with a substantially increased risk of developing lung cancer in the ipsilateral lung, but there is no clear evidence of an increased risk with modern techniques.”

Several factors had an unclear effect, e.g. age at treatment, while others such as adjuvant chemotherapy, were not a risk factor.

Unsurprisingly, smoking was found to be an critical risk factor, with the risk also increasing in those women who smoked and received prior radiotherapy.

Overall, the simple message of this story is those women with breast cancer who have smoked and received radiotherapy will be at a greater risk of getting secondary lung cancer later in life than those who did not.

References: Lorigan, P., Califano, R., Faivre-Finn, C., Howell, A., & Thatcher, N. (2010). Lung cancer after treatment for breast cancer The Lancet Oncology, 11 (12), 1184-1192 DOI: 10.1016/S1470-2045(10)70056-5