In a nutshell
This study aimed to investigate the influence of the time of starting adjuvant chemotherapy on survival outcomes in different types of breast cancer.
This study concluded that more aggressive breast cancers require early adjuvant chemotherapy.
Some background
Surgery to remove the tumor is a commonly used treatment method for breast cancer patients. Sometimes neoadjuvant chemotherapy is administered before surgery to help shrink the tumor allowing a less complicated surgery. Adjuvant chemotherapy (AC) is the treatment that is given after surgery to prevent recurrence of the cancer.
It is not known for certain what the optimal time period to leave between surgery and AC is, and whether this varies for patients with different subtypes of breast cancer.
Methods & findings
This study involved 1408 women with stage I,II or IIIa breast cancer who had undergone surgery at one cancer center. Patients were divided into 3 groups. Group A had received AC in the first 4 weeks following surgery. Group B had received AC 4 to 8 weeks after surgery. Group C had received AC at least 8 weeks after surgery. Disease free survival (DFS, time from treatment until cancer return) and overall survival (OS, time from treatment until death from any cause) rates were measured.
Group C patients were 86% more likely to have decreased DFS and twice as likely to have decreased OS when compared to group A. There was no difference in survival rates between group A and group B.
Patients with luminal A tumors (a less aggressive form of estrogen receptor positive breast cancer) who received delayed AC had no increased risk of recurrence of cancer.
Patients with luminal B (a more aggressive form of estrogen receptor positive cancer) who delayed AC were 93% more likely to have decreased DFS. Patients with triple negative breast cancer (not dependent on estrogen or HER2 for growth) were 2.55 times more likely to have decreased DFS. And patients with HER2 positive tumors (dependent on HER2 for growth) who had not been treated with trastuzumab were 2.41 times more likely to have decreased DFS.
The bottom line
This study concluded that a longer delay between surgery and AC is associated with decreased survival. It was also concluded that AC should be started early in patients with aggressive tumor types.
The fine print
Further investigations need to be carried out in different populations.
What’s next?
Consult your physician about the best time to start AC after surgery.
Published By :
Oncotarget
Date :
Jul 04, 2017
