Researchers have studied the trends of anal cancer cases over the past 15 years and identified about 69,000 cases of anal cancer and more than 12,000 deaths during this time.
"Our findings of a dramatic increase in the incidence of black millennia and white women, rising rates of disease distress and an increase in cancer mortality rates are very worrying," study lead author Ashish A. Desmuk, assistant professor The UTEF School of Public Health said in a statement. "Given the historical perception that anal cancer is rare, it is often overlooked."
Distant disease is when cancer spreads to other parts of the body.
From 2001 to 2015, the most common types of anal cancer increased by 2.7% annually, while the death rate of anal cancer increased by 3.1% annually from 2001 to 2016.
The study, published in the Journal of the National Cancer Institute, "gives numbers of a trend that seems to be happening in the last decade," said Dr. Virginia Schaefer, colorectal surgeon and associate professor at the Winship University Cancer Institute. "In that sense it gives us numbers of what we already expected." Schafer was not included in the study.
Anal cancer occurs where the digestive tract ends. It is different from colon or rectal cancer and most similar to cervical cancer.
The most common subtype of anal cancer is squamous cell carcinoma, caused by human papillomavirus, known as HPV.
Who is affected by anal cancer?
The study showed that the incidence of anal cancer was significantly increased in people aged 50 and over.
Rates of anal cancer are also rising in young blacks.
The study also found that the number of advanced stage patients was increasing. This may be partly because HIV treatment is improved, Schafer said, which means patients live longer with compromised immune systems, and cancer can progress further until it is diagnosed.
Stopping the stigma
There is still a stigma around anal cancer.
"I know there are people who are ashamed," Kroes told the CBS this morning in June. "You have cancer. Do you then also feel like ashamed how you did something wrong because it took up residence in your anus? “
Anal cancer has become "pretty taboo", said Schafer, "I think because of some of the risk factors that were known to be historically related to it.
"If people have symptoms, they should go to a doctor because I think a lot of people think, 'Oh, well, it's just hemorrhoids' and don't check things out and that can potentially mean that you aren't diagnosed until much, much later “.
To bolster prevention efforts forward, Schafer said that all people who are eligible to be vaccinated should do so and that current vaccination guidelines should be studied to determine if they can be extended to other patients.
CNN's Michael Nedelman, Lisa Reapers France and Sandy Lamoth contributed to this report.