One Sigmoidoscopy Boosts Colon Cancer Survival Odds
TUESDAY, April 27 (HealthDay News) -- Adults who undergo a sigmoidoscopy examination between ages 55 and 64 could significantly reduce their odds of developing and dying from colorectal cancer, new research shows.
Flexible sigmoidoscopy enables doctors to look for cancers and symptomless growths called adenomas in the rectum and sigmoid (lower) colon, where two-thirds of colorectal cancers occur. Sigmoidoscopy does not examine the upper colon, as colonoscopy does.
Noting that most people with distal colon cancer (rectum and lower colon) will have developed an adenoma by age 60, the researchers theorized that removing adenomas through sigmoidoscopy would provide lasting protection.
In a long-term study, British researchers found that having the cancer-screening test just once in that age range reduced the incidence of colorectal cancer by one-third.
"The results from our trial show that flexible sigmoidoscopy is a safe and practical test and, when offered only once to people between ages 55 and 64 years, confers a substantial and long-lasting protection from colorectal cancer," the authors wrote in a study released online April 27 in advance of publication in an upcoming print issue of The Lancet.
Colorectal cancer is the third most common cancer worldwide (fourth in the United States), resulting in one million diagnoses and 600,000 deaths a year. Survival rates are good for cancers that haven't spread, so early detection is key.
Many countries promote fecal occult blood tests for early screening, but that technique reduces mortality by only 15 percent, according to background information in the study.
For their study, begun nearly 16 years ago and conducted in England, Wales and Scotland, the research team followed almost 113,000 men and women in a control group and another 57,099 participants in an intervention group, of which 40,674 (71 percent) underwent flexible sigmoidoscopy.
Over an average 11 years of follow-up, 2,524 participants were diagnosed with colorectal cancer (1,818 in the control group and 706 in the intervention group). Deaths certified from colorectal cancer totaled 727 (538 in the control group, and 189 in the intervention group), the study authors noted.
Incidence of distal colorectal cancer fell by 50 percent. Cases of colorectal cancer among those screened were reduced by 33 percent and deaths by 43 percent, the authors said.
"Confining results to the rectum and sigmoid (lower) colon, incidence was reduced by half in those who were screened," wrote Wendy Atkin of Imperial College London, and colleagues.
To learn more about flexible sigmoidoscopy, see the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.
HPV Test Beats Pap Smear for Cancer Screening
WEDNESDAY, April 28 (HealthDay News) -- Doctors can detect more serious precancerous lesions in the cervix by testing for human papillomavirus (HPV) than through conventional cervical screening with a Pap smear, a new study suggests.
HPV, a common sexually transmitted disease, can cause cancers such as cervical cancer. The disease is especially prevalent in young women.
In the new study, led by Ahti Anttila of the Finnish Cancer Registry, researchers studied the experiences of 58,282 women aged 30 to 60 who took part in routine cervical screening between 2003 and 2005.
The women were randomly assigned to receive an HPV test or a Pap smear test. The researchers then tracked the women for five years.
The HPV screening tests did a better job at detecting serious precancerous lesions on the surface of the cervix, known as cervical intraepithelial neoplasia (CIN III), according to the report published online April 28 in the BMJ.
The researchers cautioned that they didn't detect very many cervical cancer cases. Still, they wrote, "considering the high probability of progression of CIN III lesions in women aged 35 years or more, our results are important for prevention of cervical cancer."
The U.S. National Cancer Institute has more on cervical cancer.
Study Makes Strides in Understanding Ovarian Cancer
MONDAY, April 26 (HealthDay News) -- New understanding about the early stages of ovarian cancer may lead to the development of a new screening test for the cancer, U.S. researchers say.
In the study, scientists uncovered early tumors and precancerous lesions in inclusion cysts, which fold into the ovary from its surface.
"This is the first study giving very strong evidence that a substantial number of ovarian cancers arise in inclusion cysts and that there is indeed a precursor lesion that you can see, put your hands on, and give a name to," lead author Jeff Boyd, chief scientific officer at Fox Chase Cancer Center in Philadelphia, said in a news release. "Ovarian cancer most of the time seems to arise in simple inclusion cysts of the ovary, as opposed to the surface epithelium."
Boyd and his colleagues analyzed ovaries removed from women with BRCA gene mutations (who have a 40 percent lifetime risk of developing ovarian cancer) and from women with no known genetic risk factors for ovarian cancer.
In both groups of women, gene expression patterns in the cells of inclusion cysts were dramatically different than normal ovarian surface cells. For example, the cells of inclusion cysts had increased expression of genes that control cell division and chromosome movement. The researchers also found that cells from very early tumors and tumor precursor lesions frequently had extra chromosomes.
"Previous studies only looked at this at the morphologic level, looking at a piece of tissue under a microscope," Boyd said. "We did that but we also dissected away cells from normal ovaries and early-stage cancers, and did genetic analyses. We showed that you could follow progression from normal cells to the precursor lesion, which we call dysplasia, to the actual cancer, and see them adjacent to one another within an inclusion cyst."
With these findings, researchers can try to develop new screening tests to detect ovarian cancer in the earliest stages, when it is still treatable. Ovarian cancer kills nearly 15,000 women in the United States each year. Fewer than half of ovarian cancer patients live more than five years after diagnosis.
The study was published April 26 in the journal PLoS One.
The American Cancer Society has more about ovarian cancer.
Cancer Drug Seems to Work by Activating Virus
FRIDAY, April 23 (HealthDay News) -- The cancer drug cyclophosphamide activates a viral infection that helps anti-viral medications eliminate a virus-linked cancer, says a new study.
The drug is used to treat Burkitt lymphoma, an aggressive, fast-growing type of non-Hodgkin lymphoma that often occurs in children. In Africa, the cancer is caused by the Epstein-Barr virus (EBV), which typically remains dormant inside tumor cells.
This study of 21 patients, ages 5 to 15, who were being treated with cyclophosphamide, found that the drug triggers an active EBV infection. Increased replication of the virus in cancer cells makes the cells more susceptible to antiviral drugs, which kill cells containing the replicating virus.
The study was published in the April issue of the journal Clinical Cancer Research.
"What we have learned from this work is a potential means of capitalizing on presence of viral genomes within tumor cells to alter those tumor cells in a way that makes them more susceptible to treatment. Our findings have implications for other EBV-related malignancies that, overall, are among the most common cancers worldwide," Dr. Margaret Gulley, a professor of pathology and laboratory medicine at the University of North Carolina at Chapel Hill School of Medicine, said in a news release.
EBV infects more than 90 percent of people worldwide and is associated with a number of diseases including lymphomas, gastric cancer, and nose and throat cancer.
The next step in this research is a clinical trial to test the use of a cancer drug and an antiviral drug simultaneously, Gulley said.
The U.S. National Library of Medicine has more about Burkitt lymphoma.