Bronte Doyne, 19, knew something was wrong when she constantly felt sick, tired and was "getting thinner by the second", but her family, from Nottingham in Britain, says she had to beg doctors to take her fears seriously as her condition deteriorated.

In a diary entry less than a month before her death in March 2013, Bronte wrote: "Mum tried to talk to my consultant but he didn't give her much help. She even had to ask him when I was going to get my appointment for the oncologist. Really don't think he likes my mum asking questions."

Her mother, Lorraine, claims that, at one point, a doctor told them to "stop Googling" Bronte's symptoms, according to the Nottingham Post.

Now, the Nottingham University Hospitals NHS Trust has apologised, saying its "communication with Bronte and her family fell short".

"We did not listen with sufficient attention. We should have referred Bronte to the expert support available from the Teenage Cancer Trust much sooner," the NHS Trust's medical director, Dr Stephen Fowlie, told the Nottingham Post.

"We are sharing the learning from Bronte's experience. Lorraine is assisting us to improve how we help patients."

The newspaper reported that Bronte was first admitted to hospital in September 2011 with suspected appendicitis, but was soon diagnosed with fibrolamellar hepatocellular carcinoma.

It is a rare type of cancer that an estimated 200 people, typically young adults, are diagnosed with each year worldwide.

Bronte had liver resection surgery in December 2011, and was told she had would "be fine", her family says.

But Ms Doyne said she and her daughter started researching the cancer online, and came across the US-based Fibrolamellar Cancer Foundation. On the website, which Ms Doyne said was endorsed by the White House, they read that there was a high chance the cancer would return.

About seven months after her surgery, and after doctors had told her she was fine, Bronte tweeted:

my body does not feel very good #helpme— Bronte Doyne (@BronteDoyne) July 29, 2012

She wrote in her diary, parts of which her mother has since made public, of constantly feeling ill.

"Feeling sick for months now. Tired of this feeling crap. Hospital not worried so trying to get on with it," she wrote in her diary in November 2012.

She also wrote that she was told by her GP to go to the hospital's emergency room when her symptoms worsened, about six weeks before her death.

But when she got there, she was told by a doctor that she didn't need to be seen.

"I got so angry because the doctor was so rude and just shrugged his shoulders," she wrote in her diary.

"He gave me a sarcastic comment like you can sleep here if you want but they won't do anything. So I just have to wait for another hospital appointment."

She claimed her feeling that "something's not right" was ignored, and a doctor rationalised her weight loss by saying she was "part of a skinny family".

It was only after her mother "chased results" from a six-monthly MRI scan that they discovered Bronte had an abdominal growth, the Nottingham Post reported.

Bronte was then referred to a Teenage Cancer Trust unit, where she stayed for 10 days before she died.

Ms Doyne, who questioned why her daughter was not referred to the Cancer Trust earlier, is now working with the NHS Trust to improve how the service works with patients.

In a long statement published on the Nottingham Post, Keith Girling, the deputy medical director at the NHS Trust, said "the internet age and the availability of information can challenge the way we respond to patients who may be very well informed ... but can remain frightened and vulnerable".

However, he warned that some websites "are inaccurate or misleading, and may give false hope or cause distress. They may not be relevant to the unique clinical and other circumstances of the patient.

"Clinicians and patients and families must together learn how to sift this information to deliver intelligence, and to match patients to potential treatments, while delivering care which is caring and sensitive to each individual patient's needs and preferences," he said.

"The internet can be a powerful tool, especially if its users are helped to exploit its strengths to help deliver the best possible NHS care (and to avoid its drawbacks)."