Anal cancer is on the rise, especially in women. Should they be screened?

July 23, 2019 / BIOON / - actress Marcia Cross's anal cancer has been relieved for about a year, and now she has a mission "I want to help people get rid of their prejudice against anal cancer," the 57 year old former desperate housewife actress said in a recent interview with people magazine I've read many stories of cancer survivors, and many people - especially women - are too shy to say what kind of cancer they have It's a shame I hope that this phenomenon and can be eliminated "Cross was diagnosed with depression in November 2017 and is not the first celebrity to say that we need to overcome neuroticism Actress Farrah Fawcett has made a documentary about her struggle to end her life with anal cancer in 2009 Photo source: https://cn.bing.com but Cross came out at the right time Although anal cancer (short tube at the rectum end, solid waste is excreted through it) is still rare, its incidence rate has been increasing steadily over the past few decades, and there are far more women than men in this area The American Cancer Society estimates that 5530 women and 2770 men will be diagnosed with cancer this year; about 760 women and 520 men will die In response to this worrying trend, experts in oncology, pathology, gynecology, infectious diseases and other fields think it's time to start screening for anal cancer in some women At present, there is no recognized screening guidelines, because it is very complex The average woman has a small risk of anal cancer in her lifetime (2 / 100000), so, as experts explained in their 2016 paper screening for anal cancer in women, figuring out which women to check and the best way to check them is challenging "We don't want to spend a lot of testing resources and create a lot of anxiety in low-risk women," said Joel M palefsky, an infectious disease doctor and anal cancer expert at the University of California San Francisco But there are some low-risk women who can be vigilant To better understand why screening all women doesn't make sense, we need to consider the cause of 90% of anal cancer: human papillomavirus (HPV) HPV is a ubiquitous family of sexually transmitted viruses that live in cells on the surface of the anus, cervix, vagina, vulva, penis, mouth and throat Although the immune system can eliminate most asymptomatic infections, persistent infection with high-risk HPV types can cause cancer in these organs Photo source: https://cn.bing.com it should be noted that Gardasil vaccine (recommended for use in adolescence) can prevent nine high-risk types of infection and two types of genital warts But the vaccine was still underutilized and was not used until 2006 The tricky thing is that HPV does not behave the same in all organizations Due to unclear reasons, the cervix is likely to develop into HPV driven precancerous lesions Although the study found that the incidence rate of anal HPV in healthy women is high, there is no HPV driven precancerous lesion in the anus Anna Barbara moscicki, a pediatrician at the University of California Los Angeles and a HPV researcher and lead author of the screening paper, said the rarity of anal lesions can only be partially explained by immune responses and sexual behavior "Why is the cervix more vulnerable than the anus? We don't know, "she said Defining "high risk" in order to demonstrate the theory that anal smear screening can detect pre cancer and thus reduce cancer, palefsky of the University of California, San Francisco, led a government funded clinical trial called anchor When lesions were found in women and men in the trial, they were randomly assigned to be treated or monitored every six months Both groups were followed for five years The trial was limited to people who are known to have a high risk of anal cancer, that is, those with HIV The virus can damage their immune system, so they are very susceptible to HPV infection One study found that more than a quarter of HIV positive women had severe precancerous lesions of the anus Another group recommended by experts to screen for anal cancer is organ transplant recipients, who take immunosuppressive drugs to prevent organ rejection Larger groups - women who have been treated for cervical cancer, cancer or vulvar cancer - may benefit from screening, experts say But there is not enough data to prove it "Their risk is higher, but we don't know how high," palefsky said Another issue raised by screening concerns the availability of high-resolution endoscopy, the gold standard procedure for diagnosing anorectal smear abnormalities During the 15 minute procedure, without any bowel preparation, the clinician uses a thin cylindrical mirror to examine the anal canal If necessary, tissue samples or biopsies can be taken for laboratory analysis Colonoscopy provides greater tissue magnification than colonoscopy, which is used to screen for colorectal cancer But not many people have been trained to do anal endoscopy, at least not yet "There are about 50 clinics in the United States that do this," said Naomi Jay, a San Francisco practice nurse She is also the president of the seven-year-old International Association for anal cancer, which helps bring together experts who write screening papers The final screening dilemma may be the trickiest Although the risk of anal cancer among ordinary women is minimal, experts wrote, "this group of healthy women accounts for the largest proportion of women with anal cancer." For them, the way out of screening is through digital rectal examination, where clinicians touch the anal canal with their fingers Digital examination can not detect pre cancer, and its effectiveness depends on the skill of clinician (this is different from the digital examination as part of the pelvic examination ）But for Marcia Cross, it's all different The actresses had no symptoms of anal cancer, such as bleeding or pain They say her gynecologist found her tumor at a relatively early stage of her routine examination by digital rectal examination She said chemotherapy and radiation, while "crude," were successful "Marcia was lucky because she had a gynaecologist who did the tests," Jay said "At the very least, every woman should have a digital rectal examination "Reference: [1] anal cancer is on the rise, especially in women Should they be screened