After a second surgery, it was found the cancer had spread to her lymph nodes.
"At first, before reading any information, I was not overly worried. But when I started to read more information about it, it dawned on me the seriousness of the situation," Lauren said.
"I was definitely in disbelief at first. Even now I struggle to accept the circumstances. I can't believe I have cancer."
Lauren has received two Keytruda treatments at a private facility in Tauranga and has a further 16 to go.
She said it was "unbelievable" each treatment cost about $10,000.
"It is a huge amount of money to come up with and when you're placed in a situation where the best option is so [exorbitant], it definitely causes a lot of conflicts," she said.
"The thought of putting so much strain on my family was overwhelming and I still experience huge guilt associated with the treatment.
"To walk into every treatment it just seems unbelievable to be paying $10,000 each time."
Lauren said the entire situation had been "extremely anxiety-provoking" and hard to come to terms with.
"The hardest part has been coming to terms with this treatment and what it means for my life from now on. It's been very draining, easy to get into a rut of feeling down when I try to make sense of it."
But she was grateful for consistent support from loved ones.
"I am lucky to have good support, especially from my family who have been there from the start. I wouldn't have made it to here without them."
Lauren believed there was a "misconception around melanoma in young people". She urged young people to protect themselves from the sun, and take skin cancer seriously.
"I just want young people to know that it can happen at a young age and if they are bothered by a mole or notice changes, don't hesitate to get it checked.
"The earlier it is caught, the better."
Lauren said she was yet to meet someone else her age with melanoma so it had been hard to access support.
Cancer Society of New Zealand chief executive Lucy Elwood said cancer was "fortunately rare" in people under 45. However, of the cancers detected in young people, melanoma was the most common.
She said in 2019, there were 2726 melanoma registrations in New Zealand. Of those registrations, 141 were people under 45 years.
Pharmac's director of operations, Lisa Williams, said Keytruda was only funded for unresectable melanoma, meaning that able to be removed by surgery, or for metastatic stage 3 or stage 4 melanoma.
She said if a patient had resectable disease or local without metastatic disease and has had surgical resection, they would not meet funding criteria.
Williams said they had received an application to access Keytruda treatment, to treat people who had a surgical resection.
"Our Cancer Treatments Subcommittee assessed it in August 2019, but it deferred making a recommendation until further data on risks and benefits of treatment is available."
Williams said early diagnosis and treatment were key to minimising illness and death in people with melanoma.
She said Pharmac staff took their "decision-making responsibility seriously".
"When you manage a fixed budget, there will always be more medicines than we can afford to fund. This means we need to make some difficult choices."
