Health officials have "failed brain tumour patients and their families for decades", a damning new report has concluded.
Patients with brain tumours are let down at every stage - from diagnosis and treatment to research funding, MPs said.
The Petitions Committee said it had little reason to believe the Department of Health had "grasped the seriousness of the issue".
MPs criticised the Government for not taking the lead in identifying gaps in research and providing funding for new studies which could help save lives.
The Petitions Committee concluded that funding for brain tumour research is inadequate and not given sufficient priority.
Brain Tumour Research said just 1% of the national spend on cancer research is allocated to studies into brain tumours.
The report comes after a bereaved sister set up a petition calling for more research into brain tumours - it has since been signed by more than 120,000 people.
Maria Lester began campaigning after her brother Stephen Realf died from a brain tumour aged just 26.
The aspiring RAF pilot was 19 when he first noticed symptoms and after his diagnosis he was forced to leave military training and move back in with his parents in Rugby, Warwickshire.
But in the years following his diagnosis he tried to live each day to the full, his sister said.
"As soon as he was diagnosed with the tumour we knew his life would be limited by this illness and we had to make the most of the time that we had with him," Mrs Lester said.
"We tried to make every minute count."
She said she hoped her brother would be proud of what has been achieved so far.
"Before he died he said that he was worried he wasn't going to have the opportunity to make a difference.
"I hope that even though he's not here, the fact that he has inspired this campaign is going to be the legacy he leaves and I think he would be very proud of that."
Mrs Lester welcomed the report but said she would continue her fight, adding: "We are going to keep shouting and keep getting louder until someone in Government finally hears what we are saying and does something about it."
The report concludes: "There has been little improvement in the prognosis for brain tumour patients over the last 30 years."
It adds: "Brain tumour research has been seriously underfunded over decades, putting it far behind many other cancers in terms of the improvements in outcomes for patients."
Helen Jones, chairwoman of the Petitions Committee, said: "We heard testimonies both from victims of this terrible disease, and from clinical specialists working in the area.
"The evidence was clear - something must be done to improve outcomes for patients, and barriers to research must be removed."
The report states that funding for site-specific brain tumour research comes mostly from the voluntary sector but the MPs said the Government "must not leave charities to tackle this devastating disease alone".
Ministers should also play a greater role in identifying gaps in funding by setting priorities for research, it states.
MPs also said more must be done to raise awareness of the disease.
The Petitions Committee called on the Government to give a clear statement on whether it thinks current levels of funding are adequate and, if not, what it plans to do to ensure that funding for brain tumour research increases.
George Freeman, Minister for Life Science, said: "Early diagnosis and treatment of cancer, including brain tumours, is a priority for this government.
"The Government invests more than £1 billion every year into health research and works closely with patients, charities and our world-leading life sciences industry to support further research into this devastating disease."
Commenting on the report, Sue Farrington Smith, chief executive of Brain Tumour Research, said: "This ground-breaking report, published on the back of our successful e-petition initiated by Maria Lester and her family, makes it clear that brain tumour patients have been failed at every hurdle.
"The recommendations to the Government are bold and clear: implement an early diagnosis strategy for GPs and clinicians; use their influence to galvanise the game-changing levels of funding for brain tumour research needed to provide effective treatments; and remove the systematic barriers to continuous and sustainable brain tumour research.
"Together we will find a cure."
Sarah Lindsell, chief executive of The Brain Tumour Charity, added: "The lack of funding for research is a part of the much wider issue for brain tumour patients, which includes a lack of awareness of signs and symptoms leading to late diagnosis which, in turn, can mean poor outcomes and poor quality of life."