In a nutshell
The authors evaluated whether there was a difference in the treatment response rates between invasive lobular carcinoma and invasive ductal carcinoma.
Some background
Invasive lobular carcinoma (ILC) is characterized as cancer that begins in the milk-producing lobules that then spreads to surrounding breast tissue. Invasive ductal cancer (IDC) is characterized as cancer that begins in the milk-carrying ducts that then spreads to surrounding breast tissue.
These two cancer sub-types are often grouped together in many studies. There are now reports, however, that they are distinct cancer types, with invasive lobular carcinoma being the more aggressive of the two, with a decreased response to treatment.
Methods & findings
The aim of this study was to determine the effects of neo-adjuvant chemotherapy (NAC – chemotherapy provided before surgery designed to shrink the tumor) on tumor response in patients with ILC and IDC. Depending on the response of the tumor to NAC, the patient may be eligible for breast-conserving therapy (BCS – surgery to remove the tumor and only some surrounding breast tissue).
A total of 53,929 women with breast cancer were evaluated. 6401 women had ILC and the remaining 44,597 had IDC. 7% of those with ILC received NAC compared to 8% of those with IDC.
Overall, patients with IDC were almost twice as likely to undergo BCS than those with ILC. This resulted in a higher mastectomy rate (removal of the entire breast – a more invasive surgery) in the ILC group.
49.7% of ILC patients and 69.6% of IDC patients saw shrinkage of their tumors following NAC. 24.4% of ILC patients and 39.4% of IDC patients underwent BCS.
A complete response (tumor disappearance) was seen in 5% of those with ILC compared to 20.2% of those with IDC.
The bottom line
The authors concluded that patients with ILC were less likely to see a complete or partial response to NAC, and were less likely to undergo BCS than patients with IDC.
What’s next?
Regardless of your breast cancer sub-type, discuss NAC with your doctor, as it can improve the likelihood of surgery opportunities.
Published By :
Annals of Surgical Oncology
Date :
May 19, 2015
