Operable breast cancers are often treated with chemotherapy first to shrink the tumor and allow breast-conserving surgery (BCS). Currently, the conventional treatment period of 4 months is not effective for all patients. This study showed that extending the treatment is a safe and attractive alternative, which can make BCS more widely available.
The context
Chemotherapy treatment for breast cancer is usually combined with surgery. Traditionally, the breast is partially or completely removed, and chemotherapy is given to destroy any leftover cells. Alternatively, a less drastic BCS can be performed. This is the preferred therapeutic procedure when breast cancer is detected early. It provides the same overall survival as a complete removal, but with a much better cosmetic effect. However, among other conditions, it is limited to small tumors. More patients can become eligible for BCS when they receive a chemotherapy treatment first to shrink the tumor.
This type of treatment is already widely accepted. However, in ER+, postmenopausal women this isn’t the case. They can be treated with letrozole, which is sold under the name Femara. However, the drug’s use before surgery is hampered by the poor response rate over the standard duration of treatment. This hasn’t been optimized experimentally, but is chosen to be 4 – 6 months based on typical chemotherapy durations. It is limited in time out of fear for disease progression during longer treatments. Recent clinical trials with longer treatments did show a significant reduction in tumor size, and advantages were suggested for treatments as long as 12 months. In this study, the optimal duration of letrozole treatment was investigated
The nuts and bolts
A total of 139 postmenopausal, ER+ breast cancer patients with large tumors, that were ineligible for BCS, were treated for up to 12 months. They were evaluated by ultrasound every 2 months to determine the tumor size and follow up their disease progression.
The results were very promising, as BCS had become possible for a total of 69% of patients at the end of the study. The median time for sufficient response was 7.5 months, which is longer than the standard treatment duration. Furthermore, the drug was also well tolerated during this prolonged therapy with only mild-to-moderate side effects, mainly hot flushes. While there were concerns that the disease would progress during this longer treatment, this was proven wrong. Among the patients who underwent a complete breast removal, the disease hadn’t progressed after 3 years in 69% of patients. In patients who received the letrozole treatment and BCS, this was the case for 96% of patients.
How will this help me?
Overall, given its low toxicity and beneficial results, extending the duration of letrozole treatment is an attractive and safe alternative to the currently used fixed period. These findings will likely increase the uptake of this therapy, and increase the availability of BCS for ER+, postmenopausal patients.
Source
Optimum duration of neoadjuvant letrozole to permit breast conserving surgery – Breast Cancer Research and Treatment (2014)