Actress Marcia Cross is best known in her role as "picture-perfect" housewife Bree Van de Kamp on ABC's "Desperate Housewives." But according to a in People magazine, her past year and a half has been far less than perfect. In November 2017, Cross was diagnosed with anal cancer after a routine digital rectal examination by her gynecologist. The cancer was caught early, and she underwent 6 weeks of radiation and chemotherapy.
Throughout the treatment, which Cross described as "gnarly," she tried to maintain her sense of humor. "In the beginning, I just sort of lay down for the parting of the cheeks and I would float away," she says. "Because what are you going to do?"
Now, after settling into her "new normal," Cross thought it was important to share her story:
"I want to help put a dent in the stigma around anal cancer. I've read a lot of cancer-survivor stories, and many people, women especially, were too embarrassed to say what kind of cancer they had. There is a lot of shame about it. I want that to stop."
She encourages people to listen to their body, and quickly seek medical advice if they have any symptoms (rectal bleeding or pain, itchiness, or lumps). She also acknowledged the Anal Cancer Foundation as "an amazing resource, and one I turned to often."
Anatomy:
The anus is approximately 2 to 3 inches long and composed of a surface layer of squamous cells under which are two adjacent sets of sphincter muscles. The internal sphincter muscle can be felt as a muscular ring at the end of the anal canal.
The anal canal is divided into three parts. The zona columnaris is the upper half of the canal and is lined by simple columnar epithelial cells. The lower half of the anal canal, below the pectinate line, is divided into two zones separated by Hilton's white line (intersphincteric groove). The two zones are the zona hemorrhagica and zona cutanea and are lined by stratified squamous, non-keratinized and stratified squamous keratinized epithelium, respectively. The keratinized stratified squamous epithelium, which lacks hair follicles, and apocrine and sweat glands, extends from the anus to the true epidermis of the perianal skin.
Incidence, Risk Factors, and Prognosis:
Anal cancer is an uncommon malignancy and accounts for only a small percentage (4%) of all cancers of the lower alimentary tract. According to the , it is estimated that in 2019 there will be 8,300 new cases and 1,280 deaths from anal cancer in the U.S.
However, there has been an of anal cancer over the past 30 years. Rates are increasing at a rate of approximately 2% a year.
Human papillomavirus (HPV) infection is the strongest risk factor for anal cancer and is accepted as a causal agent of squamous cell carcinoma of the anus and its precursor lesions. Behaviors or medical conditions that either indicate HPV infection or facilitate HPV transmission or persistence are associated with increased risk; these include history of HPV-related cancers, high-risk sexual practices such as sex between men, receptive anal intercourse, and numerous sexual partners, HIV infection, and chronic immunosuppressive states. Cigarette smoking is also a risk factor.
Anal cancer is usually curable. The three major prognostic factors are site (anal canal vs perianal skin), size (primary tumors smaller than 2 cm in size have better prognoses), and whether the tumor has spread to the lymph nodes.
Types:
Squamous cell (epidermoid) carcinomas make up most of all primary cancers of the anus. A second type, called cloacogenic (basaloid transitional cell) tumors, constitutes the remainder. Both types are associated with HPV infection. Adenocarcinomas from anal glands or fistulae formation and melanomas are rare.
Most clinicians also treat squamous cell carcinoma of the perianal skin as they would anal cancers.
Symptoms:
The most common symptoms of anal cancer include:
- Bleeding from the anus or rectum (45% of patients)
- Pain or pressure in the area around the anus (30% of patients)
- Itching or discharge from the anus
- A lump near the anus
- A change in bowel habits
Twenty percent of patients have no tumor-related symptoms.
Treatments:
Historically, anal cancer was treated by surgical means -- typically by abdominoperineal resection -- a radical procedure which removed the anorectum and necessitated a permanent colostomy.
However, today the standard of therapy is a combination of chemo- and radiation therapy, sometimes referred to as combined modality therapy. This approach can cure many patients while preserving the integrity of the anal sphincter. Fluorouracil (FU) plus mitomycin given during radiation therapy is currently the regimen of choice. FU is infused on days 1 to 4 and 29 to 32. Mitomycin is given on days 1 and 29. Radiation therapy consists of external beam RT that covers the pelvis from the S1-S2 level, inguinal lymph nodes, and anus over a course of 6 weeks.
Side effects from treatment include perineal skin reaction, acute gastrointestinal toxicity and, in those treated with FU/mitomycin, hematologic toxicity including febrile neutropenia.
New Approaches:
Everywhere you turn these days, immuno-oncology drugs (such as immune checkpoint inhibitors) are being used to treat an increasingly wide variety of cancer types and anal cancer is no exception. We spoke with an expert, Cathy Eng, MD, a professor at the University of Texas MD Anderson Cancer Center in Houston, about what's currently under investigation.
According to Eng, "early stage patients with anal cancer are treated with combined modality therapy with curative intent. However, there are some patients who have a high risk of recurrence, based on tumor size (>4 cm) or lymph node metastases. There is a clinical trial that is currently testing whether treatment with [the immune checkpoint inhibitor] nivolumab for six months after CMT improves disease-free survival."
Eng also described another trial for patients whose cancers have not responded to previous treatment and have metastasized. "This trial is testing whether nivolumab alone, or in combination with another checkpoint inhibitor ipilimumab" may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread.
Michele R. Berman, MD, and Mark S. Boguski, MD, PhD, are a wife and husband team of physicians who have trained and taught at some of the top medical schools in the country including Harvard, Johns Hopkins, and Washington University in St. Louis. Their mission is both a journalistic and educational one: to report on common diseases affecting uncommon people and summarize the evidence-based medicine behind the headlines.