Scientists unravel resistance to breast cancer treatment
By Sola Ogundipe
A research team from the university of Manchester’s Paterson Institute for Cancer Research has identified a molecular flag that will help doctors predict which patients will respond best to complementary hormone therapy with tamoxifen.
The research, funded by the charity Breakthrough Breast Cancer and published in Plos One, looked at the connective tissue surrounding the tumour, which is known to send signals that help the cancer to grow.
The team, part of the Manchester Cancer Research Centre, found that
fibroblast cells — the cells that make up connective tissue in our
bodies -differ in their characteristics from patient to patient and can give clues about tamoxifen treatment response
Tamoxifen — used alongside traditional chemotherapy and radiotherapy
– blocks the female hormone estrogen that, in certain breast cancers, is required by the tumour to grow and it has been shown to improve cancer survival rates by up to one third.
However, about one third of patients with the appropriate type of breast cancer — known as estrogen receptor positive breast cancer –do not respond to tamoxifen or develop resistance to the drug.
Estrogen receptor positive breast cancer is the most common form of
the disease accounting for 70 percent of cases.
When used alongside traditional cancer therapies, Tamoxifen has been shown to be highly effective in some breast cancer patients, but, in a third of cases, the result has not been encouraging.
Scientists hope to predict which patients will respond to tamoxifen,and those who won’t, so the correct treatment is provided instantly which will improve disease outcomes.
They analysed tissue samples from 564 women with invasive breast
cancer, some of whom were given tamoxifen and some who weren’t; this allowed us to make a comparison between treatment responses.
They discovered that women who had low levels of a protein known as
pERK in their cancer-associated fibroblasts did not respond to
tamoxifen. Testing patients for the pERK flag could help doctors
determine whether tamoxifen is an appropriate treatment for their
patient or whether alternative therapies should be explored, so saving time and money.
The researchers now plan to further study molecular flags that are characteristic for cancer-associated fibroblasts.
Understanding how fibroblasts help the tumour to grow will allow the development of new strategies to block their harmful signals and overcome drug resistance.
4 types of breast cancer identified
A comprehensive study has categorized breast cancer into four types, already leading to new ideas on how to treat the different strains.
Scientists are now a step closer to understanding the genetic origins of the four major subtypes of breast cancer.
According to Nature, the study is part of a project that includes
similar studies of lung and colon cancer.
A consortium of researchers analysed tumours from 825 patients, using six different technologies to examine subsets of the tumours for various defects.
The four main subtypes confirmed by the study are luminal A, luminal B, HER2-enriched and basal-like.
One key finding shows that one of the subtypes is genetically more
similar to ovarian tumours than to other breast cancer tumours.
Patients with that specific mutation, categorized as basal-like, may benefit from the same type of chemotherapy used to treat ovarian cancer, the researchers said.
Cancer patients with luminal A had much better prognoses than those
with luminal B, which could help doctors understand when to treat
patients more aggressively.
And researchers are planning a new clinical trial based on the
findings for HER2 patients, who often — but not always — respond
well to a drug called Herceptin, allowing a more targeted group to get the drug (and others, who may not respond to it, to avoid it).