Cancer kills mum-of-four after being told she was 'too young' for a pap smear test.

A young mum-of-four has died after a year-long battle with cervical cancer.

Sadie Blackston, from Kent, was just 25 when she passed away surrounded by family and friends in her family home.

She left behind her four children – Morgan, seven, Kenzie, five, Ellisia, four, and two-year-old Harvey.

Blackston was diagnosed with cervical cancer in January 2016, and underwent chemotherapy and radiotherapy before doctors told her the cancer had spread to her cervical lymph nodes and was no longer treatable, Kent Online reports.

The cancer was so aggressive it destroyed part of her bowel, and Blackston was living with a colostomy bag and a catheter.

Sadie's younger sister, Lizzie, has claimed Sadie was not offered a pap smear test by doctors because she was 'too young'.

Lizzie, 23, said her sister had visited the GP three or four times complaining of pain and bleeding, but was not offered a smear test, despite the fact there was a history of cervical cancer on their mum's side of the family.

Instead, Sadie was sent home with painkillers.

Her cancer wasn't discovered until she collapsed and had to be rushed to hospital.

"The cancer would definitely have been caught earlier if she had been given a smear test," Lizzie told Kent Online.

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"The age [for regular testing] should be lowered to 16 because that's when you can legally have sex. There are so many women in their early twenties who get cervical cancer, the age should definitely be lowered," she said.

In the UK, the current age when women start having regular pap tests is 25.

Lizzie said her sister deteriorated rapidly in the last few days of her life.

"She was okay on Saturday...she was sitting up and she ate a bit of chicken," she said.

"But by Sunday she was very poorly and we couldn't understand what she was saying."

Sadie passed away the following Tuesday.

"She was a lovely person and a very loving mum, sister, daughter, auntie and friend," Lizzie said of her sister.

"Everyone loved Sadie. I'm lost for words to be honest. We are all devastated, ripped apart. She will never be forgotten."

Her family and friends are now crowdfunding to help pay for Sadie's funeral and provide for her four children.