According to an article recently published in the Journal of Clinical Oncology, patients with breast cancer who received radiation therapy following a mastectomy have a significantly increased risk of developing lung cancer if they have ever smoked.
Patients with breast cancer may often undergo a mastectomy as part of their therapy. A mastectomy refers to the surgical removal of the entire breast that contains the cancer plus nearby lymph nodes and/or tissue. Following a mastectomy some patients may undergo radiation therapy, referred to as postmastectomy radiotherapy (PMRT), to that area to kill cancer cells that may remain following surgery.
Results from studies have determined that PMRT for breast cancer is associated with an increased risk of lung cancer, as it is theorized that the radiation to the chest affects the lung. As well, it has been firmly-established that smoking increases the risk of lung cancer. Researchers from New York recently conducted a clinical study to evaluate the potential that smoking in addition to PMRT may have in increasing the risk of developing lung cancer.
This study included 113 patients who had been initially diagnosed with breast cancer followed by a subsequent diagnosis of lung cancer 10 years or more following their breast cancer diagnosis. These patients were matched according to age, survival, and year of breast cancer diagnosis with a group of 364 breast cancer patients who did not develop subsequent lung cancer.
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- Among non-smoking women, those who received PMRT did not experience a higher rate of lung cancer than those who did not receive PMRT.
- Compared with never-smokers, the risk of lung cancer among ever-smokers increased nearly six-fold among women who did not receive PMRT and nearly 19-fold among women who did receive PMRT.
- Smoking plus PMRT was associated with more than a 37-fold increased risk of developing lung cancer on the side of the chest where the radiation was given and a 10.5-fold increased risk for lung cancer on the other side of the chest.
The researchers concluded: “Clinicians should consider including smoking history in their discussions with patients about the risks and benefits of PMRT.”
Women who have received PMRT and are smokers may wish to discuss lung cancer screening measures with their healthcare provider.
Reference: Kaufman E, Jacobson J, Hershman D, Desai M, Neugut Al. Effect of breast cancer radiotherapy and cigarette smoking on risk of second primary lung cancer. Journal of Clinical Oncology. 2008; 26, 392-398.