Background: The finding of a decrease in contralateral breast cancer incidence following tamoxifen administration for adjuvant therapy led to the concept that the drug might play a role in breast cancer prevention. To test this hypothesis, the National Surgical Adjuvant Breast and Bowel Project initiated the Breast Cancer Prevention Trial (P-1) in 1992. Methods: Women (N = 13 388) at increased risk for breast cancer because they 1) were 60 years of age or older, 2) were 35‐59 years of age with a 5-year predicted risk for breast cancer of at least 1.66%, or 3) had a history of lobular carcinoma in situ were randomly assigned to receive placebo (n = 6707) or 20 mg/day tamoxifen (n = 6681) for 5 years. Gail’s algorithm, based on a multivariate logistic regression model using combinations of risk factors, was used to estimate the probability (risk) of occurrence of breast cancer over time. Results: Tamoxifen reduced the risk of invasive breast cancer by 49% (two-sided P<.00001), with cumulative incidence through 69 months of follow-up of 43.4 versus 22.0 per 1000 women in the placebo and tamoxifen groups, respectively. The decreased risk occurred in women aged 49 years or younger (44%), 50‐59 years (51%), and 60 years or older (55%); risk was also reduced in women with a history of lobular carcinoma in situ (56%) or atypical hyperplasia (86%) and in those with any category of predicted 5-year risk. Tamoxifen reduced the risk of noninvasive breast cancer by 50% (two-sided P<.002). Tamoxifen reduced the occurrence of estrogen receptor-positive tumors by 69%, but no difference in the occurrence of estrogen receptor-negative tumors was seen. Tamoxifen administration did not alter the average annual rate of ischemic heart disease; however, a reduction in hip, radius (Colles’), and spine fractures was observed. The rate of endometrial cancer was increased in the tamoxifen group (risk ratio = 2.53; 95% confidence interval = 1.35‐4.97); this increased risk occurred predominantly in women aged 50 years or older. All endometrial cancers in the tamoxifen group were stage I (localized disease); no endometrial cancer deaths have occurred in this group. No liver cancers or increase in colon, rectal, ovarian, or other tumors was observed in the tamoxifen group. The rates of stroke, pulmonary embolism, and deep-vein thrombosis were elevated in the tamoxifen group; these events occurred more frequently in women aged 50 years or older. Conclusions: Tamoxifen decreases the incidence of invasive and noninvasive breast cancer. Despite side effects resulting from administration of tamoxifen, its use as a breast cancer preventive agent is appropriate in many women at increased risk for the disease. [J Natl Cancer Inst 1998;90:1371‐88]

/pdf/tamoxifen-for-prevention-of-breast-cancer-report-of-the-2kp9cx2d4k.pdf

Tamoxifen for Prevention of Breast Cancer: Report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study

Background The current practice of removing adenomatous polyps of the colon and rectum is based on the belief that this will prevent colorectal cancer. To address the hypothesis that colonoscopic polypectomy reduces the incidence of colorectal cancer, we analyzed the results of the National Polyp Study with reference to other published results. Methods The study cohort consisted of 1418 patients who had a complete colonoscopy during which one or more adenomas of the colon or rectum were removed. The patients subsequently underwent periodic colonoscopy during an average follow-up of 5.9 years, and the incidence of colorectal cancer was ascertained. The incidence rate of colorectal cancer was compared with that in three reference groups, including two cohorts in which colonic polyps were not removed and one general-population registry, after adjustment for sex, age, and polyp size. Results Ninety-seven percent of the patients were followed clinically for a total of 8401 person-years, and 80 percent returned...

Prevention of colorectal cancer by colonoscopic polypectomy. The National Polyp Study Workgroup.

Efforts to reduce global cancer disparities begin with an understanding of geographic patterns in cancer incidence, mortality, and prevalence. Using the GLOBOCAN (2002) and Cancer Incidence in Five Continents databases, we describe overall cancer incidence, mortality, and prevalence, age-adjusted temporal trends, and age-specific incidence patterns in selected geographic regions of the world. For the eight most common malignancies-cancers of lung, breast, colon and rectum, stomach, prostate, liver, cervix, and esophagus-the most important risk factors, cancer prevention and control measures are briefly reviewed. In 2002, an estimated 11 million new cancer cases and 7 million cancer deaths were reported worldwide; nearly 25 million persons were living with cancer. Among the eight most common cancers, global disparities in cancer incidence, mortality, and prevalence are evident, likely due to complex interactions of nonmodifiable (ie, genetic susceptibility and aging) and modifiable risk factors (ie, tobacco, infectious agents, diet, and physical activity). Indeed, when risk factors among populations are intertwined with differences in individual behaviors, cultural beliefs and practices, socioeconomic conditions, and health care systems, global cancer disparities are inevitable. For the eight most common cancers, priorities for reducing cancer disparities are discussed.

Patterns of Cancer Incidence, Mortality, and Prevalence Across Five Continents: Defining Priorities to Reduce Cancer Disparities in Different Geographic Regions of the World

https://www.medpagetoday.com/upload/2008/3/6/CRC.pdf

Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology.

https://louisville.edu/medicine/departments/medicine/divisions/gimedicine/physician-resources/lectures/gi-neoplasms/surveillance-colonoscopy

Colorectal cancer screening and surveillance: clinical guidelines and rationale-update based on new evidence

Background Sigmoidoscopy may reduce colorectal cancer mortality by identifying both cancers and precursor lesions (including polyps) for treatment; however, evidence regarding the efficacy of this technique as a screening procedure is extremely limited. Purpose In the absence of data from randomized controlled trials, we performed a retrospective case-control study to determine if sigmoidoscopy screening is associated with a reduction in colorectal cancer mortality. Methods The medical records of 66 members of the Greater Marshfield Community Health Plan (GMCHP) who died of large-bowel cancer from 1979 to 1988 were reviewed for history of screening for colorectal cancer (case subjects). For comparison, the records of 196 GMCHP members of similar gender, age, and enrollment duration were randomly selected for review (control subjects). Results History of screening sigmoidoscopy was much less common among case subjects (10%) than among control subjects (30%). Risk for death from colorectal cancer was reduced among individuals having had a single examination by screening sigmoidoscopy (odds ratio = 0.21; 95% confidence interval = 0.08-0.52), compared with the risk for those who never had one. The reduction in risk appeared to be limited to tumors in the rectum and distal colon. Neither fecal occult blood testing nor digital rectal examination was associated with a reduction in colorectal cancer mortality. Conclusions These results suggest that screening sigmoidoscopy can substantially reduce mortality from cancers of the rectum and distal colon.

Screening Sigmoidoscopy and Colorectal Cancer Mortality

Using data from the 1986 Adult Use of Tobacco Survey, we analyzed smoking-cessation methods used by adult smokers in the United States who tried to quit. About 90% of successful quitters and 80% of unsuccessful quitters used individual methods of smoking cessation rather than organized programs. Most of these smokers who quit on their own used a "cold turkey" approach. Multivariate analysis showed that women, middle-aged persons, more educated persons, persons who had made more quit-smoking attempts, and, particularly, heavier smokers were most likely to use a cessation program. Daily cigarette consumption, however, did not predict whether persons would succeed or fail during their attempts to quit smoking. Rather, the cessation method used was the strongest predictor of success. Among smokers who had attempted cessation within the previous 10 years, 47.5% of persons who tried to quit on their own were successful whereas only 23.6% of persons who used cessation programs succeeded. We conclude that cessation programs serve a small, but important, population of smokers that includes heavier smokers, those most at risk for tobacco-related morbidity and mortality. (JAMA. 1990;263:2760-2765)

Methods used to quit smoking in the United States. Do cessation programs help

The Wisconsin Epidemiologic Study of Diabetic Retinopathy. XIII. Relationship of serum cholesterol to retinopathy and hard exudate.

We conducted a 2-year, randomized, double-blind, placebo-controlled toxicity trial of therapy with tamoxifen (10 mg twice a day) in 140 postmenopausal women with a history of breast cancer and histologically negative axillary lymph nodes. These women had been treated with surgery with or without radiotherapy. At a 3-month evaluation, tamoxifen-treated women showed a significant decrease in fasting plasma levels of total cholesterol and low-density lipoprotein (LDL) cholesterol, which persisted at 6- and 12-month evaluations. During the first 12 months, plasma triglyceride levels increased; small but significant decreases in high-density lipoprotein cholesterol (HDL) were observed in tamoxifen-treated women, but ratios of total cholesterol to HDL cholesterol and of LDL to HDL cholesterol changed favorably. While data relating lipid/lipoprotein profiles and cardiovascular disease are limited in women, current evidence suggests that total cholesterol and possibly low-density lipoprotein cholesterol are risk factors. We conclude that during the first 12 months of treatment, tamoxifen exerts a favorable effect on the lipid profile in postmenopausal women with early stage breast cancer.

Tanya S. Surawicz

Papers

Screening Sigmoidoscopy and Colorectal Cancer Mortality

Methods used to quit smoking in the United States. Do cessation programs help

The Wisconsin Epidemiologic Study of Diabetic Retinopathy. XIII. Relationship of serum cholesterol to retinopathy and hard exudate.

Effects of Tamoxifen Therapy on Lipid and Lipoprotein Levels in Postmenopausal Patients With Node-Negative Breast Cancer

Methods used to quit smoking in the United States: Do cessation programs help?