Anal cancer, the disease that tragically took Farrah Fawcett’s life, is a rare cancer.  Experts estimate that about 710 Americans will die of anal cancer in 2009, compared to the 50,000 citizens expected to die of colorectal cancer.

Not only is anal cancer somewhat rare, but victims of it are more likely to survive the next decade than to die from it.  Like most malignancies, though, the sooner a doctor detects anal cancer (or a risk factor to it), the better.

Since the anal canal is only an inch and a half long, physicians can often detect abnormalities by a DRE–a digital rectal exam.  But since most people consider a doctor’s gloved, lubricated finger in their anuses distasteful, most Americans eschew the yearly DRE.

Many people believe that colonoscopies can also discover anal abnormalities, but this assumption seldom proves true.  While colonoscopies facilitate detection of pre-cancer and cancer of the rectum and colon, they seldom show abnormalities of the anal canal.  So, if someone has more than one risk factor for anal cancer, she needs to schedule a DRE and talk with her physician about possible further testing.

What causes anal cancer?  While the exact cause (or causes) of this malignancy remain a mystery, most anal cancers involve abnormalities of the squamous cells–the flat cells that line the anal margin (the area leading to the outside of the body).  Also, most victims of anal cancer tend to suffer from the human papillomavirus–HPV, the most common sexually transmitted disease in the U.S. 

HPV has about 70 subtypes, and the subtype most commonly linked with anal cancer is HPV-16.  Most anal warts are caused by HPV-6 or HPV-11, which fortunately are not linked with anal cancer.

Besides anal cancer and genital or anal warts, certain subtypes of HPV are linked to over 10,000 cases of cervical cancer in the US each year.  Physicians also detect various subtypes of HPV in victims of vulval, vaginal, and penile cancers.  Moreover, over 8,000 cases of head and neck cancers are also linked to HPV.

Although most people carrying the HPV virus are unaware of it, and may never experience symptoms, HPV can cause havoc in someone’s life.  So it is wise to get tested for it!

Other risk factors linked to anal cancer include being a female–2 out of 3 victims are women.  Also, smokers are more likely to get anal cancer, as well as lung, larynx, mouth, kidney, and bladder cancer.  Another significant risk factor for anal cancer is lowered immunity, which may happen in an individual suffering from other diseases.  Lowered immunity may also come from poor nutrition or extreme dieting.

Another risk factor for anal cancer is Crohn’s disease, a chronic disease of the digestive tract.  However, a milder inflammatory disease, irritable bowel syndrome–IBS is not a risk factor for anal cancer.

No one–perhaps not even her physician–knows what caused the anal cancer that sadly took Farrah Fawcett’s life, but perhaps the celebrated actress’s tragic death will awaken interest in factors linked to anal cancer.  Perhaps medical tests and new research will save other lives.