Supraphysiologic estradiol is an independent predictor of low birth weight in full-term singletons born after fresh embryo transfer.

STUDY QUESTION: Is supraphysiologic estradiol (E2) an independent predictor of low birth weight (LBW) in singletons born after fresh IVF-embryo transfer (ET) cycles? SUMMARY ANSWER: Our results suggest that E2 > 2500 pg/ml is an independent predictor for LBW in full-term singletons born to normal responder patients undergoing fresh IVF-ET cycles. WHAT IS KNOWN ALREADY: The pathogenesis of LBW in IVF singletons remains unknown. However, recent studies have suggested that the hyperestrogenic milieu generated during ovarian stimulation may create a sub-optimal peri-implantation environment, leading to placental dysfunction, and therefore, LBW. STUDY DESIGN, SIZE, DURATION: Retrospective cohort study of normal responder patients, <40 years old, undergoing fresh IVF-ET cycles resulting in live singleton births between January 2005 and June 2014. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 6419 patients had live births after fresh IVF-ET during the study period, of which 2348 (36.6%) patients were excluded due to multiple gestation, vanishing twins or incomplete records. Perinatal outcomes recorded for all patients included birth weight, gestational age (GA) at delivery, mode of delivery and gender. Term birth, preterm birth (PTB) and LBW incidence proportions were plotted against E2 level on the day of trigger. The term LBW incidence proportion (i.e. singletons born at GA ≥ 37 weeks with birth weight <2500 g) was considered the primary outcome of interest. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 4071 patients with live singleton births were included. The median age, BMI, E2 level and birth weight for the study cohort was 36 (33-39) years, 22.3 (20.4-25.0) kg/m2, 1554 (1112.7-2179) pg/ml and 3289 (2920-3628) g, respectively. The incidence proportion of LBW rose from 6.4% (E2 2001-2500 pg/ml) to 20.7% (E2 3501-4000 pg/ml), without a corresponding rise in the incidence proportion of PTB. The odds of term LBW with E2 > 2500 pg/ml were 6.1-7.9 times higher compared to the referent E2 group. Multivariable logistic regression analysis revealed that E2 was an independent predictor for term LBW, even after adjusting for age, BMI, race, parity, infertility diagnosis, duration of ovarian stimulation, gonadotropin dosage and method of insemination (adjusted odds ratio 10.8, 95% CI 9.2-12.5). Receiver operating characteristic analysis generated an AUC estimate of 0.85 for E2 level as a predictor of LBW. LIMITATIONS REASONS FOR CAUTION: The current study did not include analyses of hypertensive disorders of pregnancy or placental abnormalities. Furthermore, all patients were normal responders and of normal BMI, possibly limiting the overall generalizability of the study. Finally, as with any retrospective study, prospective data are required to validate the role of E2 in predicting LBW. WIDER IMPLICATIONS OF THE FINDINGS: Our results emphasize the importance of minimizing the supraphysiologic elevations of E2 levels during ovarian stimulation in fresh IVF-ET cycles. This, in turn, can optimize the early peri-implantation environment and mitigate adverse perinatal outcomes such as LBW. STUDY FUNDING/COMPETING INTEREST(S): Dr Paul J. Christos was partially supported by the following grant: Clinical and Translational Science Center at Weill Cornell Medical College (UL1-TR000457-06). TRIAL REGISTRATION NUMBER: N/A.

A randomized, prospective, parallel group study of laparoscopic versus laparoendoscopic single site donor nephrectomy for kidney donation.

Few prospective, randomized studies have assessed the benefits of laparoendoscopic single site donor nephrectomy (LESS-DN) over laparoscopic donor nephrectomy (LDN). Our center initiated such a trial in January 2011, following subjects randomized to LESS-DN versus LDN from surgery through 5 years postdonation. Subjects complete recovery/satisfaction questionnaires at 2, 6 and 12 months postdonation; transplant recipient outcomes are also recorded. One hundred subjects (49 LESS-DN, 51 LDN) underwent surgery; donor demographics were similar between groups, and included a predominance of female, living-unrelated donors, mean age of 47 years who underwent left donor nephrectomy. Operative parameters (overall time, time to extraction, warm ischemia time, blood loss) were similar between groups. Conversion to hand-assist laparoscopy was required in 3 LESS-DN (6.1%) versus 2 LDN (3.9%; p = 0.67). Questionnaires revealed that 97.2% of LESS-DN versus 79.5% of LDN (p = 0.03) were 100% recovered by 2 months after donation. No significant difference was seen in satisfaction scores between the groups. Recipient outcomes were similar between groups. Our randomized trial comparing LESS donor nephrectomy to LDN confirms that LESS-DN offers a safe alternative to conventional LDN in terms of intra- and post-operative complications. LDN and LESS-DN offer similar recovery and satisfaction after donation.

Phase II trial of the farnesyltransferase inhibitor tipifarnib plus fulvestrant in hormone receptor-positive metastatic breast cancer: New York Cancer Consortium Trial P6205.

BACKGROUND: Fulvestrant produces a clinical benefit rate (CBR) of approximately 45% in tamoxifen-resistant, hormone receptor (HR)-positive metastatic breast cancer (MBC) and 32% in aromatase inhibitor (AI)-resistant disease. The farnesyltransferase inhibitor tipifarnib inhibits Ras signaling and has preclinical and clinical activity in endocrine therapy-resistant disease. The objective of this study was to determine the efficacy and safety of tipifarnib-fulvestrant combination in HR-positive MBC. PATIENTS AND METHODS: Postmenopausal women with no prior chemotherapy for metastatic disease received i.m. fulvestrant 250 mg on day 1 plus oral tipifarnib 300 mg twice daily on days 1-21 every 28 days. The primary end point was CBR. RESULTS: The CBR was 51.6% [95% confidence interval (CI) 34.0% to 69.2%] in 31 eligible patients and 47.6% (95% CI 26.3% to 69.0%) in 21 patients with AI-resistant disease. A futility analysis indicated that it was unlikely to achieve the prespecified 70% CBR. Tipifarnib dose modification was required in 8 of 33 treated patients (24%). CONCLUSIONS: The target CBR of 70% for the tipifarnib-fulvestrant combination in HR-positive MBC was set too high and was not achieved. The 48% CBR in AI-resistant disease compares favorably with the 32% CBR observed with fulvestrant alone in prior studies and merit further clinical and translational evaluation.

Profile of 513 patients with alopecia areata: associations of disease subtypes with atopy, autoimmune disease and positive family history.

BACKGROUND: Several lines of evidence support a genetic component to alopecia areata (AA), including differences in patients based on severity of AA, associated diseases and family history. OBJECTIVE: We aimed to examine clinical and genetic features of patients with AA with a focus on associated diseases, especially atopy, and family history of AA in the USA. METHODS: From 1998 to 2001, 513 patients with AA completed interviews consisting of demographic information, patient's medical history, and family history of AA. RESULTS: Forty per cent of respondents had alopecia totalis and/or universalis (AT/AU). These patients were younger at the age of onset than those with patchy AA (P < 0.001), were more likely to have associated autoimmune or atopic disease (P = 0.047), most notably atopic dermatitis (P = 0.021) and thyroid disease (P = 0.012). They also had a greater number of relatives affected by AA (P < 0.05). CONCLUSIONS: Our findings show marked associations between severity of AA, atopic dermatitis, thyroid disease and other autoimmune diseases, and extensive family history of AA, suggesting two clinically distinct subtypes of AA with the severe subtype possibly associated with greater familial autoimmunity. Further research exploring the possibility of a genetic basis to explain these clinical findings will be helpful in clarifying our understanding of AA, leading to improvements in diagnosis and treatment.

Use of and beliefs about dermoscopy in the management of patients with pigmented lesions: a survey of dermatology residency programmes in the United States.

Dermoscopy is a non-invasive technique that can be utilized for the clinical diagnosis of pigmented lesions. The aim of this study was to assess the utilization and beliefs about the usefulness of dermoscopy in the evaluation of pigmented lesions by physicians in dermatology residency programmes, and to determine the extent of dermoscopy training received by residents in these programmes. Questionnaires were sent to the directors of all the accredited dermatology residency programmes in the United States (n = 105). A follow-up postcard questionnaire was sent to the chief resident of all the responding programmes. Eighty-three physicians responded to the questionnaire (79%). Fifty-one per cent of the respondents (n = 42) reported utilizing dermoscopy. Reported reasons for using dermoscopy by respondents included the fact that it helps detect melanoma early (74%), leads to fewer biopsies (74%) and reduces patient anxiety (64%). Lack of training (51%) and lack of usefulness (42%) were amongst the reported reasons for not utilizing dermoscopy. Sixty-seven per cent of respondents reported an increase of approximately 50% in the use of dermoscopy over the past 5 years, and 45% anticipated an increase in use over the next 5 years. Thirty-eight per cent of chief residents from the responding programmes reported receiving training in dermoscopy during residency. In conclusion, half of the dermatology residency programmes currently use dermoscopy in the evaluation of pigmented lesions. The main reason for not using dermoscopy was a lack of training. Respondents anticipated a future increase in the use of dermoscopy.

Use of and beliefs about baseline photography in the management of patients with pigmented lesions: a survey of dermatology residency programmes in the United States.

Medical photography is often used in dermatology to aid in the clinical surveillance of patients with pigmented lesions. This study aimed to assess the utilization, logistics, rationale and beliefs about the usefulness of baseline photography in patients with pigmented lesions by physicians in dermatology residency programmes, and to compare current utilization to that reported in the last decade. Questionnaires were mailed to directors of all accredited dermatology residency programmes in the United States (n = 105). Eighty-three physicians responded to the questionnaire (79%). Utilization of total body and individual lesion photography was reported by 63% and 75% of the respondents, respectively; 16% of the respondents did not use any method of photography. Reasons for using photography included the following beliefs: that it helps detect early melanoma, it results in fewer biopsies, and it reduces patient anxiety. Financial and logistical constraints were reasons why some programmes were not utilizing photography. Thus baseline photography is currently used in a majority of academic dermatology programmes as an aid in the early detection of melanoma.

The effect of customized insoles on the reduction of postwork discomfort.

This study examined the effect of customized insoles in relieving postwork discomfort in healthy individuals whose jobs require long periods of standing and walking. CompuSole insoles were worn by 122 New York City Police Department officers for up to 5 weeks for an average of 7 hours per day. The officers walked an average of 3 miles per day. Before the study, one-fifth of the police officers in this study experienced foot pain or discomfort at the end of their workday; 15% had calluses, corns, or athlete's foot; 18% had sought treatment for a foot problem in the past; and 20% had worn foot orthoses. There was a significant reduction in tiredness in the feet at the end of the day after wearing the insoles, but no improvement in back or leg discomfort. At the end of the workday, 68% had less foot discomfort and 60% were more comfortable at work when wearing the insoles.

Using nurse practitioners for skin cancer screening: a pilot study.

BACKGROUND: Skin cancer screening has the potential to detect early precancerous lesions and may ultimately be important in reducing melanoma mortality. The purpose of this study was to evaluate the ability of trained nurse practitioners to accurately identify suspicious lesions in a clinical setting. METHODS: We identified five nurse practitioners who had no previous experience in evaluating skin lesions. Each nurse practitioner participated in a training program for skin cancer detection consisting of a workshop, clinical apprenticeship, and didactic lectures. RESULTS: Evaluation of nurse practitioner competency involved three assessments. First, the nurse practitioner's ability to distinguish benign and malignant lesions was assessed using clinical color slides. The sensitivity of all five nurse practitioners to refer benign and malignant lesions for dermatologic follow-up based on the slides was 100%, whereas the specificity ranged from 53% to 100%. Second, each nurse practitioner evaluated approximately 25 different patients along with a single dermatologist. The nurse practitioner's ability to correctly refer patients with suspicious lesions for dermatologic follow-up was determined based on the dermatologist's assessment of need for referral. Results suggested a referral sensitivity and specificity ranging from 67% to 100% and 62% to 100%, respectively. In the final clinical assessment, 30 patients were independently examined by two dermatologists and four nurse practitioners. Using the consensus clinical diagnosis of the dermatologists as the gold standard, the nurse practitioner's sensitivity for detecting significant skin cancer lesions ranged from 50% to 100% and the detection specificity was 99% to 100%. CONCLUSIONS: These preliminary results have important implications for skin cancer screening efforts and suggest that nurse practitioners can be trained to accurately identify and triage suspicious lesions.

Skin cancer screening and prevention in the primary care setting: national ambulatory medical care survey 1997.

OBJECTIVE: To describe skin cancer prevention and screening activities in the primary care setting and to compare these findings to other cancer screening and prevention activities. DESIGN: Descriptive study. SETTING/PATIENTS: National Ambulatory Medical Care Survey 1997 data on office-based physician visits to family practitioners and internists. MEASUREMENTS AND MAIN RESULTS: Data were obtained on 784 primary care visits to 109 family practitioners and 61 internists. We observed that the frequency of skin cancer prevention and screening activities in the primary care setting was much lower than other cancer screening and prevention activities. Skin examination was reported at only 15.8% of all visits (17.4% for family practitioners vs 13.6% for internists, P >.1). For other cancer screening, the frequencies were as follows: breast examination, 30.3%; Papanicolaou test, 25.3%; pelvic examination, 27.6%; and rectal examination, 17.9%. Skin cancer prevention in the form of education and counseling was reported at 2.3% of these visits (2.9% for family practitioners vs 1.5% for internists, P >.1), while education on breast self-examination, diet and nutrition, tobacco use, and exercise was 13.0%, 25.3%, 5.7%, and 17.9%, respectively. CONCLUSIONS: The results of this study indicate that the proportion of primary care visits in which skin cancer screening and prevention occurs is low. Strategies to increase skin cancer prevention and screening by family practitioners and internists need to be considered.

A survey of skin cancer screening in the primary care setting: a comparison with other cancer screenings.

OBJECTIVE: To determine primary care physicians' perceived importance and frequency of performance of skin cancer screening in comparison with other cancer screening examinations. DESIGN: Descriptive survey study. PARTICIPANTS: Five thousand US family physicians and internal medicine specialists randomly selected from the Official American Board of Medical Specialists Directory of Board-Certified Medical Specialists. MAIN OUTCOME MEASURES: Self-reported importance and performance of cancer screening examinations. RESULTS: Eligible physicians (1363 total: 814 family physicians and 549 internists) completed the survey with a response rate of 30%. Overall, 52% of respondents rated skin cancer screening as "extremely" important, compared with 79% for digital rectal examination, 88% for clinical breast examination, and 87% for Papanicolaou testing. Thirty-seven percent of physicians reported performing complete body skin examinations on 81% to 100% of patients, compared with digital rectal examination, for which 78% of physicians reported performing the examination on 81% to 100% of patients, or the clinical breast examination, for which 82% of physicians reported performing the examination on 81% to 100% of patients. A higher percentage of physicians in practice for more than 30 years ranked skin cancer screening as extremely important and reported a higher frequency of screening examinations. Physicians in a suburban practice setting reported performing skin examinations more often than those in urban or rural settings. Overall, the self-reported frequency of skin examination was strongly correlated with the physician's importance rating of skin cancer screening. CONCLUSIONS: A majority of primary care physicians rate skin cancer screening as extremely important. The reported importance of skin cancer screening and frequency of skin cancer examination among primary care physicians is significantly less than for other cancer examinations. This likely represents a multitude of factors, including logistic constraints and lack of consensus on the efficacy of skin cancer screening. Arch Fam Med. 2000;9:1022-1027

Signs and symptoms of melanoma in older populations.

We conducted a descriptive study to assess the relationship between increasing age and the reporting of melanoma signs/symptoms in 634 hospital-based and 624 population-based incident cases of melanoma. Multivariate logistic regression was used to evaluate the relationship between older age (> or = 50 years) and the reporting of melanoma signs/symptoms. Older patients were less likely to report itching and change in elevation of their lesions (P < 0.05). Change in color was also less likely to be reported by older patients, although not statistically significant. Ulceration of the lesion was reported significantly more by older patients (P < 0.05). Older individuals may be less likely to report itching and change in elevation/color of their lesions, but more likely to report ulceration, a symptom associated with advanced disease and poor prognosis. Further research is necessary to provide a better understanding of the development of melanoma in older populations so that new strategies can be explored to improve early detection in this age group.

Patterns of detection in patients with cutaneous melanoma.

BACKGROUND: Despite the importance of early detection in preventing mortality from melanoma, little is known regarding how patients with the disease come to diagnosis. METHODS: The authors prospectively evaluated 471 newly diagnosed melanoma patients between 1995 and 1998. Patients completed a questionnaire that included 1) identification of the person who detected the lesion, 2) the anatomic location of the lesion, and 3) family history of melanoma. Logistic regression analysis was performed to examine the relation between detection patterns and lesion thickness, adjusting for age, gender, anatomic site of the primary lesion, and family history of melanoma. RESULTS: The majority of patients detected their own melanoma (n = 270; 57%). Females were more likely to self-detect than males (69% vs. 47%; P < 0.0001). Physicians detected the melanoma in 16% of patients (n = 74), followed by "spouse" in 11% of patients (n = 51). Within this group, detection by wives was 7.5 times more common than detection by husbands (P < 0.0001). Logistic regression analysis revealed that physicians were 3.6 times more likely to detect thin lesions (

Predictive factors associated with axillary lymph node metastases in T1a and T1b breast carcinomas: analysis in more than 900 patients.

BACKGROUND: Axillary lymph node metastasis (ALNM) represents the single most important prognostic indicator in patients diagnosed with breast cancer. The proportion of < or = 1-cm (T1a, T1b) invasive breast carcinomas is increasing. The incidence and predictive factors associated with ALNM in patients with < or = 1-cm tumors remains unclear and the role of axillary lymph node dissection in these patients has been questioned. The purpose of this study was to determine clinical and pathologic factors predictive of ALNM in patients with < or = 1-cm invasive breast carcinomas by univariate and multivariate analyses. STUDY DESIGN: Review analysis from a prospective database identified patients with < or = 1-cm invasive breast cancers treated at our institution between 1990 and 1996. All patients underwent a resection of the primary tumor and axillary lymph node dissections. Routine patient and tumor characteristics evaluated included: age, race, tumor size, histologic grade, estrogen and progesterone receptor status, and lymphatic and vascular invasion. Univariate and multivariate analyses were performed. Adjusted odds ratios (OR) and 95% confidence intervals (CI) are presented. RESULTS: A total of 919 patients were identified in this study with tumors < or = 1 cm. These included 199 patients (21.7%) with T1a tumors and 720 patients (78.3%) with T1b tumors. ALNM was detected in 165 patients with an overall incidence of 18.0%. Of the ALNM group, 32 patients (19.4%) had T1a tumors and 133 patients (80.6%) had T1b tumors. Four variables were found to be significant in univariate analysis. These included: increasing tumor size, poor histologic grade, presence of lymphatic or vascular invasion, and younger age of the patient. An increase in tumor size was associated with a significant risk of ALNM (OR = 2.66, 95% CI = 1.28 to 5.75; p = 0.01). Poor tumor grade and the presence of lymphatic or vascular invasion were also associated with an increased risk of ALNM (OR = 2.69, p = 0.003 and OR = 5.52, p = 0.0001, respectively). Patients with ALNM were more likely to have a tumor grade of 3 (25.0% ALNM versus 12.5% node-negative, p = 0.004) and lymphatic or vascular invasion (16.9% ALNM versus 3.5% node-negative, p < 0.0001). In multivariate analysis, an increased risk of ALNM was demonstrated with increasing tumor size (0.1-cm increments), poor histologic grade, and younger age. CONCLUSIONS: This study investigated clinical and pathologic factors influencing ALNM in patients with T1a and T1b breast carcinomas. We have identified three factors by multivariate analysis as significant independent predictors of ALNM in this group of patients. These include increasing tumor size, poor histologic grade, and younger age. Given the significant amount of ALNM demonstrated in this study (overall 18%) and the inability to identify a subgroup of patients that had an acceptable low risk of ALNM, the complete omission of assessing the axilla for metastatic disease in patients with small breast cancers cannot be advocated. Our recommendation for patients diagnosed with T1a and T1b tumors is to have their axilla investigated for metastatic disease either by traditional axillary lymph node dissections or by intraoperative lymphatic mapping and sentinel lymph node biopsy techniques.

Evaluation of factors associated with skin self-examination.

Early detection and excision of thin lesions may be important in reducing mortality from melanoma. Periodic skin self-examination may be beneficial in identifying thin lesions. The purpose of this study was to evaluate factors associated with skin self-examination. The study population was comprised of 549 Caucasian residents of Connecticut 18 years of age or older who were selected as controls as part of a population-based case-control study on skin self-examination and melanoma conducted during 1987-1989. Personal interviews were conducted to obtain information on skin self-examination, demographics, history of cancer, phenotypic characteristics, sun exposure habits, and screening and health behaviors. Nevus counts were performed by trained nurse interviewers. Logistic regression was used to model the relationship between the variables of interest and skin self-examination. Female gender was identified a priori as a predictor of skin self-examination, and thus all analyses were stratified by gender. Age, education, and marital status were also identified a priori as important predictor variables and were selected for inclusion in the final models. Skin awareness was a strong factor associated with skin self-examination for both females and males. For females, previous benign biopsy or the presence of an abnormal mole was identified as important for future skin self-examination using our criteria. A family history of cancer, physician examination, and change in diet to reduce cancer risk increased the likelihood of skin self-examination in males but not females. In women, light hair color may increase the likelihood of performing skin self-examination. Older age and college or postgraduate education was associated with a decreased likelihood of performing skin self-examination in both males and females. Identifying factors associated with skin self-examination will enable health care providers to target individuals who may not be performing skin self-examination but who are at increased risk for developing melanoma.

Patient knowledge, awareness, and delay in seeking medical attention for malignant melanoma.

We investigated the relationship between patient knowledge, awareness, and delay in seeking medical attention for melanoma. The study population was comprised of 255 cases with cutaneous melanoma newly diagnosed during January 15, 1987 to May 15, 1989, who were part of a population-based case control study. Personal interviews were conducted to obtain information on patient's knowledge of melanoma signs and symptoms, skin awareness, delay in seeking medical attention, and related covariates. The adjusted odds ratio for the association between skin awareness and delay was 0.30 (95% confidence interval 0.12-0.71). Odds ratios ranged from 0.43 to 0.81 for knowledge and delay. Awareness of skin changes was associated with a reduced Breslow depth for stage I melanomas. Individuals who are aware of skin changes and abnormalities appear to be less likely to delay seeking medical attention for melanoma. Knowledge of melanoma signs and symptoms may also contribute to a decreased delay in melanoma diagnosis.

Heartburn risk factors, knowledge, and prevention strategies: a population-based survey of individuals with heartburn.

BACKGROUND: Twenty-five million adults experience heartburn daily. To target individuals for prevention programs, characteristics of persons with heartburn and the associated causes of this condition must first be identified. METHODS: We conducted a population-based telephone survey of 2000 individuals with heartburn to describe the cause of the disease, knowledge of risk factors, and prevention strategies. RESULTS: Lifestyle and work habits, and certain food and beverage consumption, were associated with heartburn. Women reported the onset of heartburn about 5 years later than men. Survey respondents were unaware of the risk factors for heartburn, and sex-dependent differences in knowledge were apparent. Logistic regression modeling identified increasing age, female sex, higher level of education, and frequent vs infrequent heartburn as significant (P<.02) predictors of whether patients told a physician about their heartburn symptoms. Increasing age, higher body mass index, and reduced level of education were significant (P<.02) predictors of frequent vs infrequent heartburn in this study population. CONCLUSION: The findings of this study provide a framework for the development of a heartburn prevention program based on lifestyle modification.

Estrogen replacement therapy and urinary tract infections in postmenopausal women aged 45-89.

OBJECTIVE: An elevated risk of urinary tract infections (UTIs) in postmenopausal women has been attributed to an increase in the vaginal pH. Estrogen replacement therapy (ERT) helps restore the vaginal milieu and may have a beneficial effect on risk of infection. Studies examining the association between ERT and UTIs have been inconsistent. We conducted a nested case control study to clarify this relationship in women aged 45-89. DESIGN: For each case, we selected up to five control women, matched by year of birth. We used pharmacy records to classify women as new users, past users, ongoing users (past and new users), and never users of ERT. There were 254 cases and 1,268 controls. RESULTS: The risk ratio for UTI was 1.02 [95% confidence interval (CI) 0.74, 1.40] for any use versus never use, after adjustment for health care utilization. The risk ratio for the association between new use and UTI was 1.13 (95% CI 0.46, 2.77). For ongoing users the risk ratio was 1.08 (95% CI 0.76, 1.54), whereas the risk ratio for past use was 0.77 (95% CI 0.39, 1.48). CONCLUSIONS: Our results do not support a protective effect of ERT on the risk of UTIs.

The role of epidemiology in cancer prevention.

Cancer is a major cause of morbidity and mortality throughout the world. As the population lives to an older age, cancer incidence and mortality are expected to increase because of the strong relationship between cancer and advancing age. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Epidemiologic study designs include descriptive, ecologic, cross-sectional, and analytic (cohort, case-control, and intervention) studies. In the past 50 years, epidemiologic research has helped to elucidate many risk factors for cancer. Lifestyle factors such as smoking, diet, alcohol consumption, reproduction (pregnancy, lactation, age at menarche, and menopause), obesity, and inactivity have been suggested as the major contributors to the development of cancer. Epidemiologists have demonstrated that cancer is largely an avoidable disease and estimated that more than two-thirds of cancer might be prevented through lifestyle modification. Epidemiologic research is crucial to public health and cancer prevention. Individuals or communities at increased risk of cancer can be targeted for risk factor modification, as well as for secondary prevention and chemoprevention strategies.

The epidemiology of physical activity and cancer.

Experimental studies in animals and epidemiological studies in human populations support an inverse association between exercise and the development of cancer. Physical activity has been shown to be protective against the development of breast and colon cancer and may also be important for other kinds of cancer such as that of the prostate. The proposed biological mechanisms for the physical activity--cancer association include exercise's effect on immune function, transit time of digestion, hormones, and body fat. There has been little research on physical activity and the effect on progression of cancer, although there are studies to suggest that it may slow the clinical course of the disease. Furthermore, exercise may be beneficial in the treatment of cancer through mood elevation, decreased loss of lean tissue, and increased quality of life. Much is still to be learned about the effect of exercise on cancer. The intensity, duration, frequency, and type of exercise that is relevant need to be clarified. As well, the time period during life when exercise is important has not been determined. It seems reasonable to conclude that exercise, a modifiable risk factor, is beneficial in preventing certain forms of cancer. Public health interventions may hold promise for cancer prevention.