Interrupting radiotherapy for TNBC linked to worse survival

Topline

Even 2 days off from radiotherapy for triple-negative breast cancer (TNBC) may affect overall survival.

Methodology

• Clinicians sometimes give women with TNBC a break between radiation sessions so that their skin can heal.
• To gauge the impact, investigators reviewed data from the National Cancer Database on 35,845 patients with TNBC who were treated between 2010 and 2014.
• The researchers determined the number of interrupted radiation treatment days as the difference between the number of days women received radiotherapy versus the number of expected treatment days.
• The team then correlated treatment interruptions with overall survival.

Takeaway

• Longer duration of treatment was associated with worse overall survival (hazard ratio, 1.023).
• Compared with no days or just 1 day off, 2-5 interrupted days (HR, 1.069), 6-10 interrupted days (HR, 1.239), and 11-15 interrupted days (HR, 1.265) increased the likelihood of death in a stepwise fashion.
• More days between diagnosis and first cancer treatment of any kind (HR, 1.001) were associated with worse overall survival.
• Older age (HR, 1.014), Black race (HR, 1.278), race than other Black or White (HR, 1.337), grade II or III/IV tumors (HR, 1.471 and 1.743, respectively), and clinical N1-N3 stage (HR, 2.534, 3.729, 4.992, respectively) were also associated with worse overall survival.

In practice

“All reasonable efforts should be made to prevent any treatment interruptions,” including “prophylactic measures to reduce the severity of radiation dermatitis,” and consideration should be given to the use of hypofractionated regimens to shorten radiation schedules.

Source

The study was led by Ronald Chow, MS, of the Memorial Sloan Kettering Cancer Center, New York, and was published in the Journal of the National Cancer Institute.

Limitations

• The findings may not be applicable to less aggressive forms of breast cancer.
• Treatment interruptions may have been caused by poor performance status and other confounders that shorten survival.

Disclosures

The study was funded by the National Cancer Institute. The investigators had no disclosures.

A version of this article appeared on Medscape.com.