Genetic
mutation hastens the recurrence of breast cancer and reduces the survival
rate.'
Mutations
in the female hormone-related gene (ESR1) have been verified by Gangnam
Severance Hospital researchers to speed up breast cancer recurrence, impede endocrine
therapy, and reduce survival rates.
A
research team from Gangnam Severance Hospital has found that mutations in the
female hormone-related gene (ESR1) have an unfavourable influence on breast
cancer patients. Professors Jung-Joon, Ahn Sung-gui, and Bae Seung-joon are
pictured from left to right.
The
female hormone oestrogen is one of the main causes of breast cancer. In 70% of
breast tumours, oestrogen receptors can be detected. ESR1 is the gene that
codes for the oestrogen receptor, and when it mutates, it prevents endocrine
therapy from working and accelerates breast cancer progression.
ESR1
mutations are found in 20-30% of metastatic breast cancer tissues when
oestrogen receptor-positive breast cancer spreads to other organs.
Based
on the hypothesis that the first breast cancer contains an ESR1 mutation, the
team, lead by Professors Jung-joon, Ahn Sung-gui, and Bae Seung-joon of the
Department of Breast Surgery, used a digital polymerase chain reaction (PCR)
test to try to discover the ESR1 mutation.
From
1997 to 2015, the researchers took paraffin blocks from initial cancer samples
from 121 individuals with oestrogen receptor-positive breast cancer who had the
recurring disease after surgery. The researchers discovered five types of ESR1
mutations after analysing the DNA retrieved from the sample: E380Q, Y537C,
Y537N, Y537S, and D538G.
Following
further investigation, the researchers discovered ESR1 mutations in nine of the
121 individuals (7.4 percent).
Patients
with the mutation had a 23-month relapse-free time, which was significantly
shorter than the 49-month relapse-free period for patients without the
mutation.
In
the group of patients with the mutation, the overall survival period was just
51 months, compared to 211 months in the group without the mutation.
In
the case of primary endocrine therapy resistance, which is defined as
recurrence within two years of endocrine therapy, the researchers found that 75
per cent of patients with ESR1 mutations (six out of eight) were in the primary
therapy-resistant group, compared to only 24 per cent of patients without the
mutation.
Professor
Ahn added, "This study implies that taking the new medicine right after
breast cancer surgery can assist enhance treatment outcomes." "The
findings will be used by the team as essential clinical data in the creation of
patient-specific endocrine therapy in the future."