Drawing on years of experience in cancer research and patient care, The University of Texas M. D. Anderson Cancer Center released today the most comprehensive, risk-based screening guidelines publicly available to date for breast, cervical and colorectal cancers.
The new recommendations represent the first wave of an effort by M. D. Anderson to improve the effectiveness of efforts to prevent and detect cancer at its earliest, most treatable stage by reconstructing and expanding its screening, risk reduction and diagnostic guidelines across eight disease sites.
Available on M. D. Anderson's Web site, the recommendations translate best practices in cancer prevention employed at M. D. Anderson into accessible guidelines the public can follow, with risk categories identified and information about when to begin and discontinue screening exams.
According to the American Cancer Society, more than 40 percent of Americans will develop cancer during their lifetime, and cancers that can be prevented or detected earlier by screening account for at least half of all new cancer cases.
"Cancer screening is not one-size-fits-all," said Therese Bevers, M.D., medical director of M. D. Anderson's Cancer Prevention Center. "Our new risk-based recommendations are markedly more personalized and precise, offering detailed guidance than what has previously been made available to the public here or by other cancer organizations."
Until now, cancer screening recommendations were targeted largely to individuals at average risk for developing cancer based on characteristics like age, family history or genetic predisposition. However, average risk was not previously defined and recommendations for individuals at increased or high risk were not outlined. The new screening guidelines define risk and offer recommendations for those at increased and high risk of developing cancer. For example, there are now five different sets of screening recommendations for those at increased risk for breast cancer; four categories of age-based risk recommendations for cervical cancer; and for colorectal cancer, there are three categories defining those at increased risk and three categories defining those at high risk.
The new guidelines build on established cancer screening practices and now more specifically offer the following recommendations:
Starting at age 20, women at all risk levels should practice breast self-awareness by being familiar with how their breasts look and feel and immediately reporting any changes to their doctor. Women aged 40 years and older at average risk should get annual mammograms and breast exams.
For women at increased risk, the type and frequency of exams - including clinical breast exams, mammograms and breast MRI - depend on factors putting them at increased risk, including:
- history of radiation treatment to the chest;
- genetic predisposition;
- diagnosis of lobular carcinoma in situ;
- Gail Model score of greater than 1.7 percent;
- or family history.
For women at average risk, it is now recommended that women under age 21 get a liquid-based Pap test within three years of initiating vaginal intercourse. She should continue to have Pap tests annually until she has had three consecutive negative test results. After that, M. D. Anderson recommends screening every two years unless she is at increased risk of cervical cancer based on risk factors, including:
- history of cervical cancer or severe cervical dysplasia;
- persistently testing positive for Human Papilloma Virus (HPV);
- exposure to diethylstilbestrol (DES) before birth;
- Human Immunodeficiency Virus (HIV) infection;
- or an immune system that does not function properly.
Beginning at age 30, adding HPV testing is a preferred option to the Pap test, and if both are negative, a woman may go to every three years unless she is at increased risk based on the risk factors cited above or unless the optional HPV test was not done.
M. D. Anderson recommends a colonoscopy every 10 years (preferred screening), a virtual colonoscopy every five years, or a yearly Fecal Occult Blood Test (FOBT) for men and women aged 50 years and older who are at average risk. For men and women at increased or high risk, the type and frequency of exams - including colonoscopy and flexible sigmoidoscopy - depend on the following factors:
- personal history of precancerous (adenomatous) polyps;
- personal history of colorectal cancer;
- family history of colorectal cancer or precancerous (adenomatous) polyps;
- genetic diagnosis of Familial Adenomatous Polyposis;
- genetic history of Hereditary Nonpolyposis Colorectal Cancer or a clinical history suggesting such;
- or inflammatory bowel disease (ulcerative colitis or Crohn's disease).
"Because of the research being conducted in laboratories and clinics at M. D. Anderson and around the world, our understanding of how cancer develops and spreads is steadily increasing," said Ernest T. Hawk, M.D., M.P.H., vice president for Cancer Prevention and Population Sciences.
More knowledge about how doctors make decisions about risk levels and screening tests will give patients a deeper understanding of the disease process and enable them to put their own cancer risk in perspective, he added.
"For colorectal cancer screenings, patients need to be proactive about obtaining results from their screening tests. For example, if a colonoscopy reveals polyps, it is critical for the patient to know what kind, how many and what size, since this information factors heavily into what risk category they fall into for colorectal cancer," Bevers said.
The risk categories and related guidelines were developed by multidisciplinary panels of M. D. Anderson disease site experts across several areas, including: medical oncology, surgical oncology, cancer prevention, imaging and others. Risk-based screening guidelines for prostate, liver, skin, endometrial and ovarian cancers are currently in development and a new online risk assessment tool integrating the new screening guidelines will be launched on the M. D. Anderson Web site in early 2010.