Anal cancer has risen by up to 111% in the UK since the early 1990s, statistics show.
Rates of the unusual disease have skyrocketed in women, but increased by a more modest 22% among British males, according to Cancer Research UK.
And it’s not just the UK, scientists from The University of Texas in Houston found anal cancer rose by up to 2.7% every year between 2001 and 2015 in the US.
One sufferer was Desperate Housewives’ star Marcia Cross, 57, who beat the disease earlier this year after six weeks of “gnarly” treatment, People magazine reported.
Original Charlie’s Angel Farrah Fawcett died from the disease aged 62 in 2009 after it spread.
Marcia was diagnosed in November 2017 following a routine check-up with her gynaecologist, People reported.
Due to it being caught early, the actress managed to avoid surgery but required chemo and radiotherapy.
Since being given the all-clear, she is keen to raise awareness of the disease, while breaking down its stigma.
“Having woken up to its importance, I am now a big fan of the anus!” Marcia told People.
“Every time I go to the bathroom, I think, ‘That’s awesome! Thank you, body’.”
What is anal cancer? And what causes it?
Anal cancer primarily affects the anal canal, which is found at the end of the bowel.
The anal canal, which is around 3-to-4cm long (1.18-to-1.57 inches), connects the anus to the rectum to enable faeces to be excreted from the body.
“Nearly all” anal cancers (90%) develop in the cells that line the canal’s walls, according to MacMillan.
The disease can also arise in the glandular cells, which produce mucus. This is rare, making up less than 5% of anal-cancer cases, MacMillan statistics show.
In rare incidences, a type of skin cancer can develop in the area around the anus itself.
Melanoma, the most malignant form of skin tumours, makes up less than 1% of anal cancers.
Anal cancer affected around 1,400 new people a year in the UK between 2014 and 2016, Cancer Research UK statistics show.
In 2016, 990 women in the UK were struck down with the disease, compared to 500 men.
Almost three in five (57%) patients diagnosed in England live at least 10 years after their diagnosis, regardless of their sex.
As a result, anal cancer is not among the “20 most common causes of cancer death”.
Why anal cancer is on the rise, and more common in women, is not entirely clear.
The disease is associated with a history of tumours in the vagina, vulva or cervix, which only affect women.
However, this is just one of a string of risk factors.
Infection with the human papillomavirus (HPV) is a known cause, according to the NHS.
The “very common virus” is carried by four in five (80%) people at some point in their life, Jo’s Cervical Cancer Trust reports.
Primarily spread via skin-to-skin contact of the genitals, HPV is usually cleared up by the immune system.
However, persistent, high-risk infections can trigger cervical abnormalities, which may develop into cancer.
“[The rise in anal cancer] is likely reflective of changes in environmental exposures, particularly infection with HPV, which is responsible for 86-to-97% of all anal cancers,” Dr Stephanie Greco, from the Fox Chase Cancer Center, told Prevention.com.
Anal sex can cause the anus to become infected, according to the NHS.
Having lots of sexual partners also raises a person’s risk of the disease, possibly because their odds of acquiring HPV go up, the health service adds.
Dr Ashish Deshmukh, who led the University of Texas study, pointed the finger at the “normalisation” of anal sex and having many sexual partners in recent decades, nbc news reported.
He also blamed obesity, which the NHS does not list as a cause for this specific form of the disease.
Carrying too much weight does raise the risk of tumours in general, however.
Cancer Research UK calls obesity the “second biggest preventable cause of cancer”. This is thought to be due to fat cells triggering inflammation and affecting hormone levels.
Rising rates of anal cancer may also come down to improved diagnosis.
People are also living longer, with age being a recognised risk factor for anal cancer.
Weilin Wu, health information officer at Cancer Research UK, told Yahoo UK: “Although there has been a rise in anal cancer over the last decade, it isn’t very common.
“There could be a number of reasons for the increase, including HPV and potentially better diagnosis.
“And more anal cancer cases in women are linked to HPV, so we hope to see the number of people diagnosed with the disease fall because of the HPV vaccine.”
What are the symptoms of anal cancer? And how is it treated?
Anal-cancer symptoms are similar to those caused by piles or small tears, known as anal fissures.
Bleeding from the anus is usually the first red flag, according to the American Cancer Society.
This may be followed by itching, pain or even a feeling of “fullness” around the anus.
Some also develop lumps at the anal opening and swollen lymph nodes in that area.
Also look out for a change in bowel movements, with many losing control or producing narrower faeces, the American Cancer Society adds.
Most of the time, the above will be caused by something less sinister.
However, with no anal-cancer screening programme in the UK or US, you should get any symptoms checked by a GP.
“People can come in pretty late because they don’t want it looked at or are embarrassed to have it looked at,” Dr Jack Jacoub, from the Moffitt Cancer Center, told Prevention.com.
“But then the cancer can be dragged out and more advanced when it’s finally diagnosed.”
Once spotted, treatment is usually a combination of chemo and radiotherapy - “chemoradiation” - and surgery to remove the tumour or affected area, according to the NHS.
In severe cases, the anus, rectum and part of the colon may have to be removed. This will also reduce the risk of the disease returning.
Patients will then be fitted with a permanent colostomy, which allows them to excrete waste out of their body into a bag.