Doctors need to be more aware of this cancer, and should be on the lookout for it by giving patients older than 45 both a visual and digital exam, researchers say.
"This cancer can be a real pain in the you-know-what, but in a lot more ways than just a usual bout of hemorrhoids," says Dr. Michael Felz, an associate professor of family medicine at the Medical College of Georgia in Augusta. "This type of cancer is so easily confused with something that is so common that it is easily misdiagnosed -- and to the uninitiated, it's just not very well known. Most physicians have not heard of this cancer, and they are not at all aware that this melanoma can arise in a region such as the rectum."In the September issue of the Southern Medical Journal, Felz and his colleagues describe cases of anal melanoma discovered in four patients. Each of the patients had been suffering for at least three months from what was thought to be hemorrhoidal rectal bleeding. But on closer examination, the hemorrhoids turned out to be highly invasive anal melanoma, so advanced that all four men died of the disease despite aggressive surgery and chemotherapy. The men died between eight and 37 months after diagnosis.
Most patients present with bleeding or a prolapsed hemorrhoid, Felz says. "The hemorrhoids tend to make themselves external; they protrude and they're harder than usual. The hemorrhoids are often pigmented or darkly discolored. The problem is that the incidence of the disease is so uncommon that's it's often been managed as a case of hemorrhoids with Preparation H or something. By the time diagnosis is performed, widespread cancer is already present."
Hemorrhoids are enlarged, bulging blood vessels in and about the anus and lower rectum. According to the American Society of Colon and Rectal Surgeons, over half the population will develop hemorrhoids, usually after age 30.
Anal melanoma, or skin cancer of the rectum, is relatively rare, says the senior medical consultant for the American Cancer Society. It "usually presents in an advance state, because -- like so many problems in the anal region and rectal canal -- they are treated symptomatically rather than the patient being examined regularly and thoroughly," says the consultant, Dr. LaMar McGinnis.
"We saw four cases in four years," Felz says, "which, we know, is what the larger cancer centers see." According to the American Cancer Society, anal melanoma makes up between 1 and 2 percent of all anal tumors. The society expects 3,500 people to be diagnosed with anal cancer this year.
Melanoma can be effectively treated if it's caught quickly, McGinnis adds. "When it's recognized early, it can be treated simply, with an over 90 percent cure rate," he says. "But when it's recognized in a more advance stage, when the cancer has invaded locally and spread to the regional lymph nodes, then chemotherapies and surgeries are much more extensive and the cure rates are not good."
There are no early signs of the disease, McGinnis says. The only way to discover the disease is to look for and feel a potential lesion. Other symptoms may include pain, itching, changes in bowel habits, and unexplained weight loss.
Both Felz and McGinnis says doctors need to perform both visual and digital rectal exams and look for and biopsy unusual hemorrhoids, especially those that have extended beyond the rectum or have an unusual coloration.
"It changed our practice down here, that's for sure," Felz adds. "We look at things a lot more closely."
What To Do
Melanoma is a skin cancer that, in the vast majority of cases, is found on parts of the skin that get sun exposure. But it doesn't have to, so tell your doctor if you have a hemorrhoid that doesn't respond to normal treatment.