In a nutshell
This paper studied the role of human epidermal growth factor receptor 2 (HER2, protein receptor) in ductal carcinoma in situ.
Some background
Ductal carcinoma in situ refers to cancer that starts growing from the milk ducts but has not spread to surrounding breast tissue. Treatment of ductal carcinoma in situ usually involves surgery to remove the tumour and radiation therapy. HER2 is a protein that can be found on cancer cells. The presence or absence of HER2 can determine the type of treatment that will be given as well as the prognosis (outcome) of the cancer.
Methods & findings
The authors studied whether the presence of HER2 on cancer cells in ductal carcinoma in situ is associated with a higher risk of invasive cancer (cancer that has spread to surrounding breast) or recurrence (return of cancer).
1,667 women with ductal carcinoma in situ were analyzed. Of these women, 560 had HER2 positive (presence of HER2 on cancer cells) breast cancer. The women were followed up for an average of 7.6 years. Of all these patients, 8.5% had an in-situ recurrence (return of breast cancer to milk ducts) and, 12.1% had an invasive recurrence (return of breast cancer to breast tissue). There were 16 deaths.
Overall in-situ breast cancer recurrence occurred in 11.8% of HER2 positive patients and 8.8% of HER2 negative patients. At 10 years, breast cancer recurrence occurred in 23.8% of HER2 positive patients and 24.6% of HER2 negative patients. At 10 years, invasive breast cancer occurred in 12% of HER2 positive patients and 15.8% of HER2 negative patients.
HER2 positive patients were 1.53 times more at risk of breast cancer recurrence when treated with quadrantectomy (removal of quarter of breast) without radiotherapy than when treated with radiotherapy. HER2 negative patients were 2.18 times more at risk of in-situ breast cancer recurrence when treated with quadrantectomy without radiotherapy than when treated with radiotherapy.
The bottom line
The authors concluded that HER2 positive breast cancer was associated with increased risk of in situ breast cancer recurrence, and that radiotherapy is beneficial for HER2 positive patients with ductal carcinoma in situ.
What’s next?
Discuss with your doctor about receiving radiation therapy for ductal carcinoma in situ.
Published By :
Annals of oncology
Date :
Jan 18, 2015
