More than a thousand women with breast cancer are set to benefit from a new drug that can make some "inoperable tumours operable" after health officials have said it can routinely be used in the NHS.
The National Institute for Health and Care Excellence (Nice) has provisionally given the green light to the drug pertuzumab as a treatment for the disease.
The drug, also known as Perjeta, was widely welcomed when it was first introduced by manufacturer Roche.
New draft Nice guidance recommends pertuzumab - in combination with Herceptin and chemotherapy - can be used as an option before breast cancer surgery to help shrink the cancer for patients with HER2-positive breast cancer.
Charity Breast Cancer Now described the move as a "huge leap forward", saying the drug could reduce the extent of the surgery patients required or even make inoperable cancers operable.
Nice said it was able to approve the use of the drug in draft guidance after agreeing a discount price with manufacturer Roche.
It should be used as an option among those who have HER2-positive breast cancer that is locally advanced, inflammatory, or early-stage and at high risk of coming back, Nice said.
Commenting on the news, Mia Rosenblatt, assistant director of policy and campaigns at the charity Breast Cancer Now, said: "This is a huge leap forward.
"Perjeta is the first addition to primary breast cancer treatment to be approved by Nice since 2006 and marks the introduction of a new type of breast cancer medicine, to be used before surgery.
"For the small number of women eligible, this drug could mean an enormous amount.
"It could help shrink their tumours to reduce the extent of the surgery they require or even make inoperable cancers operable.
"With eligible patients able to access this drug immediately, we can now continue to evaluate how much this promising treatment will improve patients' overall survival."
Roche said the move would benefit 1,380 women every year in England and Wales.
Of the 50,000 women and around 340 men diagnosed with breast cancer each year in the UK, about 10-15% of them were identified as HER2-positive breast cancer.
Samia al Qadhi, chief executive of the charity Breast Cancer Care, said: "This is an exciting turning point. Women with certain aggressive types of breast cancer will have access to an extra drug before surgery that can boost the success of shrinking the tumour.
"Crucially, this may mean people's long-term survival improves.
"It's wonderful news that the valuable pre-surgery treatment option of pertuzumab combined with trastuzumab will now be available on the NHS, especially after it looked unlikely earlier in the year.
"Making the most effective treatments available to the specific patients who will benefit most is essential. And this decision offers hope that we're starting to move in the right direction."
Meanwhile, Nice has announced that it has approved seven drugs for routine NHS use that were previously only available through the Cancer Drugs Fund.
The health body has been reappraising cancer drugs which had not been recommended in previous Nice guidance.
Out of nine treatments Nice has looked at so far, seven have been approved in either final or draft guidance.