Colon cancer
Programs Help Blacks Get Needed Colorectal Cancer Screening
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African-Americans are less likely than whites to be screened for colorectal cancer, and the disparity almost certainly contributes to higher mortality. A new review of studies identifies effective strategies for improving the situation, but suggests that work remains to be done.
“We have seen some success in interventions, and shown that it’s important to tailor approaches to African American individuals and to use multiple approaches, strategies, and communication media,” said review author Barbara Powe, Ph.D.
The studies’ lack of long term follow-up represents “a gap in research,” however. “We need to learn to design interventions to create patterns of screening that could enhance screening for other cancers as well,” said Powe, a registered nurse and director of Cancer Communication Science for the American Cancer Society.
Racial differences in cancer care still unexplained
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Even though black patients and white patients with rectal cancer are equally likely to consult with an oncologist, blacks are less likely to undergo additional treatment after surgery, according to research findings posted online by the Journal of the National Cancer Institute.
The lower rates of radiation and chemotherapy partially explain why long-term survival after rectal cancer surgery is up to 20 percent lower for black patients than for white patients. Dr. Arden M. Morris, at the University of Michigan in Ann Arbor, and her colleagues hypothesized that blacks may not be referred as often to medical and radiation oncologists.
Using information from a large national database, the researchers identified 2,716 patients 66 years of age or older who had undergone surgery for stage II or III rectal cancer.
Birth control pills may lower colon cancer risk
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Women who have used birth control pills seem to have a slightly decreased risk of colon cancer as they age, a new study suggests.
Researchers found that among nearly 90,000 women ages 40 to 59, those who had ever used oral contraceptives were 17 percent less likely to develop colon cancer over the next 16 years.
The findings, which appear in the International Journal of Cancer, are in line with evidence suggesting that estrogen plays a role in colon cancer risk.
Gastrointestinal stromal tumors
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Gastrointestinal stromal tumors (GIST) are tumors of the GI tract derived from mesenchymal precursor cells in the gut wall. They result from mutations of a growth factor receptor gene, C-KIT. Some are caused by previous radiation therapy to the abdomen for other tumors.
Tumors are slow growing, and malignant potential varies from minimal to significant. Most (60 to 70%) occur in the stomach, 20 to 25% in the small bowel, and a small number in the esophagus, colon, and rectum. Average age at presentation is 50 to 60.
Small-bowel tumors
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Small-bowel tumors account for 1 to 5% of GI tumors.
Benign tumors include leiomyomas, lipomas, neurofibromas, and fibromas. All may cause abdominal distention, pain, bleeding, diarrhea or, if obstruction develops, vomiting. Polyps are not as common as in the colon.
Polyps of the Colon and rectum
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An intestinal polyp is any mass of tissue that arises from the bowel wall and protrudes into the lumen. Most are asymptomatic except for minor bleeding, which is usually occult. The main concern is malignant transformation; most colon cancers arise in a previously benign adenomatous polyp. Diagnosis is by endoscopy. Treatment is endoscopic removal.
Polyps may be sessile or pedunculated and vary considerably in size. Incidence of polyps ranges from 7 to 50%; the higher figure includes very small polyps (usually hyperplastic polyps or adenomas) found at autopsy. Polyps, often multiple, occur most commonly in the rectum and sigmoid and decrease in frequency toward the cecum. Multiple polyps may represent familial adenomatous polyposis. About 25% of patients with cancer of the large bowel also have satellite adenomatous polyps.
Adenomatous (neoplastic) polyps are of greatest concern. Such lesions are classified histologically as tubular adenomas, tubulovillous adenomas (villoglandular polyps), or villous adenomas. The likelihood of malignancy in an adenomatous polyp at the time of discovery is related to size, histologic type, and degree of dysplasia; a 1.5-cm tubular adenoma has a 2% risk of containing a malignancy, vs. 35% risk in 3-cm villous adenomas.
Penile and Urethral Carcinoma
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Penile and urethral carcinomas are rare. Most physicians will never be involved in the management of such a case. Because of their rarity, delay in diagnosis secondary to both patient and physician factors are a constant threat. Any lesion of the penis that cannot be definitively diagnosed must be considered cancer until otherwise proven. Steps must then be taken to establish a definitive diagnosis or the patient should be referred to an appropriate consultant. Urethral cancer in men frequently masquerades as a urethral stricture.
The annual meeting of the American Urological Association was held in San Antonio, Texas, May 21-26, 2005. At this meeting, a number of papers were presented on these topics.
Colon cancer a disease of hormone deficiency, Jefferson team finds
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Researchers at the Kimmel Cancer Center at Jefferson in Philadelphia have found new evidence suggesting that colon cancer is actually a disease of missing hormones that could potentially be treated by hormone replacement therapy.
Reporting August 1, 2007 in the journal Gastroenterology, clinical pharmacologist Scott Waldman, M.D., Ph.D., professor and chair of pharmacology and experimental therapeutics at Jefferson Medical College of Thomas Jefferson University, and his co-workers showed that GCC – guanylyl cyclase C, a protein receptor on the surface of intestinal epithelial cells for two hormones, guanylin and uroguanylin, can suppress tumor formation. These hormones regulate the growth of intestinal epithelial cells.
