The letter, listing the dangerous treatments sold and the regulatory changes needed to prohibit them, has been shared with Mr Hancock.
A newly released BBC documentary details a number of individuals who have died following the usage of bogus treatments.
“The Department of Health needs to review legislation around alternative cancer treatments in light of these deaths,” said Mr Browne.
The nation’s Law Commissioner for Criminal Law, Penney Lewis, has said that moves to lower the threshold of criminality for online posts containing fake claims about both cancer and coronavirus treatments are under review.
Shadow Culture Minister Chris Matheson told The Telegraph that new legislative reforms could help protect the country amid an avalanche of social media propaganda.
“The Cancer Act is a fantastic piece of legislation but we know that strengthening and broadening will save lives,” he said.
“I am due to meet with constituents in the coming days who know about the pain of losing a loved one after taking deadly fake cancer treatments.
“The loss of such lives makes me upset and angry – it focuses my determination to help tighten the act and outlaw dodgy practitioners, treatments and diagnostics.
“The cross-party move to bolster the Cancer Act will save British lives – I know my part is relevant because any departments dealing with culture, data or social media are hugely relevant in this battle.”
A Department of Health and Social Care told this newspaper that the law was “under review” and that further action will be taken if deemed necessary.
“The Government is clear that we will do everything we can to protect our most vulnerable people,” a spokesperson said.
“We will not tolerate the false advertising of alternative cancer treatments, and will ensure penalties are handed for any breaches of the current law.
“We continue to keep this law under review and will take further action if we deem it necessary.”
Under the Cancer Act the publication of advertisements relating to the sales of bogus treatments is punishable by up to three months’ imprisonment.
Former Harley Street practitioner Errol Denton hit the headlines in 2013 when he was prosecuted.
Court proceedings revealed that Denton charged sick patients £650 for consultations – boasting that he could cure their cancer with herbs and blood analysis.
Westminster City Council slammed his behaviour as “twisted” and “immoral”.
Denton was found guilty on nine clauses of the Act and was forced to pay fines totalling £19,000.
The Government noted that the Cancer Act was strengthened in 2008 to enable prosecutions to proceed without the initial consultation of the Attorney General, and that while the Act was now being reviewed it did not currently have any plans to make changes.
Labour MP Barbara Keeley, who announced earlier this year that she was battling breast cancer, said that the Cancer Act needs updating immediately, following fresh exposure of loopholes in the legislation.
The health and social care select committee member said: “The Cancer Act prevents cancer treatments being advertised, but it has failed to prevent private providers using misleading claims to market their services.
“It is clear that this law needs updating for the digital age, where disinformation can rapidly spread unchecked online.”
The MP noted that during the Covid-19 pandemic many people have had their cancer scans delayed, and that some private healthcare providers were “preying” on cancer patients’ need for reassurance.
She noted that the issue of unreliable cancer tests being sold to private patients had been flagged but that the Government has failed to crack down on the practice.
The Telegraph first warned of the need for changes to the Cancer Act as far back as 2015.
An undercover investigation by the newspaper filmed practitioners telling cancer sufferers they could be cured with treatments that medical experts warned were “extremely dangerous”.
These included a salt treatment for lung cancer, a highly caustic salve solution for throat and skin cancers, and the use of industrial-strength bleach to treat autism and HIV.