Biomedical subjects

E C Lazcano-Ponce

Publications and source records attributed to E C Lazcano-Ponce.

At least 19 recordsLinked to original sources

PubMed2001

Mexico City physicians' awareness about cervical cancer prevention: implications for cancer screening.

BACKGROUND: In spite of an early cancer detection program (CCSP), Mexico has a mortality rate for cervical cancer of 16.5 per 100,000 women. METHOD: A cross-sectional study of 330 physicians at the Mexico City General Hospital evaluated their knowledge of the CCSP, etiology, diagnostic alternatives, and treatment guidelines. Variance analysis was the statistical procedure used. Replies to a questionnaire about cervical cancer prevention awareness were scored on a scale from 1 to 9. RESULTS: According to the awareness scale, the global average classification was 4.4, with 50% of the physicians scoring 4 or less. There was no difference in the CCSP knowledge scores of gynecologists (mean 4.92, 95% CI 4.2-5.3), oncologists (mean 4.85, 95% CI 4.3-5.5), pathologists (mean 5.23, 95% CI 4.9-5.6), and those in other specialties (mean 4.29, 95% CI 4.2-5.0), p > 0.05. Many respondents attributed CCSP's lack of effectiveness to public apathy (68.12%). CONCLUSIONS: The effectiveness of the CCSP can be improved by educating health professionals if this education is combined with elimination of obstacles to its use. More information is needed to justify revising how doctors are educated in terms of not only quality of the training but also the contents of pre- and postgraduate training programs.

Analysis of Variance↗

PubMed2000

Call and recall for cervical cancer screening in a developing country: a randomised field trial.

A randomised field trial was used to assess Mexican women's response to a mailed invitation for a Papanicolaou test. A sample of 4,802 women, 20 to 64 years old, chosen at random from the Mexican Social Security Institute Register were randomly assigned to an intervention and to a control group. A letter of invitation and a reminder were sent to the intervention group. A letter was also sent to the control group at the end of the follow-up period (8.5 weeks) in order to compare the response among women who received a letter in both groups. Cumulative incidence and incidence rates were used to determine the response and the speed of response, respectively. The response among women who had received the letter was 33.5% (efficacy) in the intervention group, while 5.9% (p<0.001) in the control group attended a Papanicolaou test. For the total of women invited, the response was 20.1% (effectiveness) and 3.3% (p<0.001), respectively. The response was greater in rural areas (rural vs. urban/suburban; p = 0.002) and eldest women (50-64 vs. 20-49; p = 0. 02). The response rate was 7 times grater in the intervention than in the control group (RR = 7.1; 95% CI 5.4-9.4; p < 0.001). A mailed invitation to have a Papanicolaou test substantially increases attendance by women who receive it. A mailed reminder improves results. This strategy could be implemented in addition to the ones already in use, mainly among rural and elderly women.

Adult↗

PubMed2000

Case-control study of diabetes, obesity, physical activity and risk of endometrial cancer among Mexican women.

OBJECTIVES: Obesity, hypertension and diabetes are closely associated with endometrial cancer (EC). This study evaluates the relationship between diabetes and risk of EC on the basis of obesity. METHODS: A case control study was carried out in Mexico City from 1995 to 1997. Eighty-five histologically confirmed cases were compared with 668 population-based controls obtained through frequency matching. Diabetes status, weight, height and other factors were determined through personal interviews among both cases and controls. RESULTS: Compared to women without diabetes, those with diabetes had an adjusted odds ratio of 3.6 (95% CI = 1.7, 7.4) for EC. This association was modified by body mass index (p interaction < 0.001). Compared to non-overweight and non-diabetic women, non-overweight (OR = 3.9. 95% CI = 0.88, 18.0) and overweight (OR = 5.9, 95% CI = 1.6, 21.1) diabetic women had a non-significant elevated risk of EC. However, elevated risk estimates were observed for obese diabetic women (OR = 8.0, 95% CI = 2.8, 22.7). CONCLUSIONS: Our results strongly suggest an interaction effect between obesity and diabetes that significantly increases the risk of EC. This, in turn, may explain the growing number of new EC cases recently observed in developing countries with reduced birth rates and an increased incidence of both obesity and diabetes mellitus.

Adult↗

PubMed1999

Reproductive factors of ovarian and endometrial cancer risk in a high fertility population in Mexico.

A case-control study was carried out in Mexico City during 1995-1997 among women with epithelial ovarian cancer (84 cases) and endometrial cancer (85 cases). The control group consisted of 668 healthy women, matched according to age categories. In a multivariate analysis, the reproductive risk factors for ovarian and endometrial cancer are similar. The risk of ovarian cancer was inversely related to the number of full-term pregnancies; the odds ratio (OR) was 0.17 and the 95% confidence interval (CI) was 0.05-0.54 when comparing nulliparous women versus those with more than seven pregnancies. For endometrial cancer, a similar association was observed (OR, 0.11; 95% CI, 0.04-0.34). The use of oral contraceptive hormones was inversely associated with both ovarian (OR, 0.36; 95% CI, 0.15-0.83) and endometrial cancer risk (OR, 0.36; 95% CI, 0.14-0.90). In women with a history of more than 8.7 years without ovulation, the risk of ovarian cancer decreased four times (OR, 0.23; 95% CI, 0.10-0.50), and that of endometrial cancer decreased more than five times (OR, 0.17; 95% CI, 0.08-0.35). These two neoplasms are clearly typified as hormone dependent, and it is possible to establish that "ovulation" and "exfoliative" mechanisms jointly determine the level of risk for both ovarian and endometrial cancer.

Breast Feeding↗

PubMed1999

Prostate cancer mortality trends in Mexico, 1980-1995.

BACKGROUND: In Mexico, prostate cancer (PC) is the second highest cause of mortality by cancer in men. In 1991, there were 2,473 deaths, with a crude rate of 5.66 cases per 100,000 men age 40 or over. For this same year, the ratio of proportional mortality to the total number of malignant tumors was 12.6%. Our objectives were to determine the trends and geographic distribution of mortality for PC in Mexico for 1980-1995. METHODS: Crude and adjusted mortality rates were carried out for 1980-1995. A test for trend was done using the simple lineal regression method. The standardized mortality ratio (SMR) was calculated for 1980-1995 for each Mexican state. RESULTS: The total number of deaths by PC in Mexico for 1980-1995 was 32,349. The crude mortality rate increased during that period from 3.16 to 6.75 cases per 100,000 men over age 40. The statistical trend test with respect to time was significant (P<0.0001). The state of Southern Baja California showed a higher SMR, and a smaller SMR was shown for the state of Quintana Roo. CONCLUSIONS: The mortality trends for PC increased for the period studied. It represents a serious problem for public health. We find that the central and northern states of the country, characterized by a greater industrial and socioeconomic development, are those with a higher SMR.

Adult↗

PubMed1999

Barriers to early detection of cervical-uterine cancer in Mexico.

In Mexico, a woman dies of cervical-uterine cancer every 2 hours, indicating a low impact by the national program for early detection of this cancer, principally because of problems related to quality and coverage. Through a qualitative study, we identified the principal barriers to use of the detection program from the point of view of actual and potential program users. Four focus groups were organized in standard conditions in Mexico City (urban, developed) and in the southern state of Oaxaca (rural, economically disadvantaged area). Participants were either women with at least one previous Papanicolaou (Pap) test or women who had never had the test. Barriers to Pap test use included (1) lack of knowledge about cervical-uterine cancer etiology, (2) not knowing that the Pap test exists, (3) the conception that cancer is an inevitably fatal disease, (4) problems in doctor/medical institution-patient relationships, (5) giving priority to unmet needs related to extreme poverty, (6) opposition by the male sexual partner, (7) rejection of the pelvic examination, (8) long waits for sample collection and receiving results, and (9) perceived high costs for care. To increase coverage of the early detection program for cervical-uterine cancer in Mexico, the needs, perceptions, and beliefs of women and their partners must be taken into account when developing policy and planning, given the role these factors play in the decision-making process that leads to their participation or nonparticipation in this program.

Adult↗

PubMed1998

Epidemiologic panorama of colorectal cancer in Mexico, 1980-1993.

INTRODUCTION: Colorectal cancer is the third cause of cancer-related death in the world, with 468,000 estimated deaths in 1993. In some countries mortality rates have started to decline, and survival rates have increased. In this study performed in Mexico, information is presented on the increase in mortality from this form of cancer, especially in more economically developed areas. METHODS: The mortality trend for colorectal cancer was evaluated and standardized by five-year age groups in the period 1980 to 1993. Also, the standardized mortality ratio was calculated for Mexico's 32 states, as was the possible association between mortality and indicators of rurality level and fertility rates in the different regions of Mexico. RESULTS: In the period studied, 18,962 deaths were officially reported. The average age of death was 66 years. The mortality rate among women (1.8) was significantly higher than among men (1.55 per 100,000 inhabitants). Mortality from colorectal cancer grew by 100 percent in both genders (beta = 0.089; P < 0.001), especially in the age group 34 and younger, in the 45 to 49 age group, and in the older than 75 age group (P < 0.05). The standardized mortality ratio was greater in the states in the north of Mexico. Finally, an inverse correlation was observed throughout Mexico between the rurality index (r = -0.60; P < 0.001) and the fertility rates (r = -0.43; P < 0.05) and mortality from colorectal cancer. CONCLUSIONS: In this study, there is evidence that mortality from this cancer is higher in geographic areas with greater socioeconomic development, similar to regional patterns observed in other countries. In Mexico, the coming years will see a serious epidemic in mortality from this disease; therefore, immediate attention must be given to identifying the profile of high-risk subjects and implementing early cancer detection measures.

Adolescent↗

PubMed1998

Evaluation model of the Mexican national program for early cervical cancer detection and proposals for a new approach.

INTRODUCTION: An evaluation model on cervical cancer (CC) prevention in Mexico was carried out during 1990-95, using three observation units: women at risk, screening providers, and use of health services. METHODS: A diagnostic procedure of the pitfalls was applied to the following steps of the screening procedure: Pap sampling quality, cytological diagnosis validity, compliance of women, and determinants of nonparticipation. RESULTS: The low effectiveness of screening for CC is due principally to factors associated with quality and coverage. Quality of Pap is deficient; 64 percent of a random sample of specimens lacked endocervical cells. Reading centers presented false negative indices between 10 and 54 percent. Women seek screening in a late stage of disease (55 percent with CC seek care because they have symptoms). In addition, coverage is low; in women between 15 and 49 years of age in Mexico City, 64.2 percent have a history of Pap smears, compared with 30 percent in rural areas. Knowledge of what the Pap is used for strongly determines use of screening. In rural areas, only 40 percent know the purpose of the Pap. CONCLUSIONS: This information justifies an intervention to reorganize CC screening in Mexico, through strategies for improving compliance, quality, follow-up, and treatment for abnormal screens.

Adolescent↗

PubMed1998

Evaluation of the cervical cancer screening programme in Mexico: a population-based case-control study.

BACKGROUND: This study presents the evaluation of the Mexico City Cervical Cancer Screening Programme (CCSP). Uterine cervical cancer (CC) is still a major public health problem in Mexico. Various actions aimed at reducing mortality from CC have been unsuccessful with an estimated 62000 deaths reported between 1980 and 1995. METHODS: The authors performed a study of cases and controls chosen on a population basis that included a sample of 233 cases of cancer in situ, and 397 cases of invasive cervical cancer obtained from eight hospitals, and a sample of 1005 controls representative of the general population. The results are presented stratified by case type, classified according to whether the cancer is invasive or not. RESULTS: The results show low impact of the cervical cancer screening programme in Mexico. Women who had a history of use of the Papanicolaou smear (PAP), who did not seek testing due to gynaecological symptoms and who had received their PAP results, had a 2.63 times lower risk of developing invasive cervical cancer (OR = 0.38; 95% CI: 0.28-0.52). CONCLUSIONS: The principal findings of this study in relation to the low impact of the screening programme in Mexico, are the low level of existing coverage and late use of health services by women at risk.

Adolescent↗

PubMed1997

Reproducibility study of cervical cytopathology in Mexico: a need for regulation and professional accreditation.

Due to the high rate of false negative results in diagnosis of cervical cytopathology, in many countries its practice has been transformed through the application of several interventions aimed at medical regulation to improve diagnostic accuracy. Diagnostic reproducibility of gynecological cytopathology was evaluated in a series of 20 cytology specimens [Papanicolaou (Pap)] and 20 cervical biopsy. (CB) studies in different clinical stages, during 1994. The observation unit consisted of 30 pathologists who observed 2 groups of 20 Pap and 20 CB specimens. The standard was a cytopathologist certified by the Pathological Anatomy Council of Mexico. Intraclass reproducibility in gynecological cytopathology is low in Mexico. In a group analysis, concordance increased as clinical status of the cervical lesion increased. For moderate dysplasia, concordance in Pap was kappa = 0.04, compared to 0.23 in CB. Concordance of diagnosis of invasive cancer was 0.29 for Pap and 0.64 for CB. Using weighted kappa at the individual level for all possible diagnoses, concordance varied from 0.29 to 0.59 for Pap, and 0.42 to 0.65 for CB. The problem of reproducibility in cervical cytopathology in Mexico emphasizes the need for continuing education, uniform diagnostic criteria, and the advantages of a single operational classification-possibly the Bethesda System-since current classification systems are obsolete.

Accreditation↗

PubMed1997

Conservative surgery for ovarian cancer and effect on fertility.

OBJECTIVE: A survey that compared two alternatives (conservative and radical surgery) is presented on ovarian cancer treatment evaluating its effect on progression-free survival and fertility, in a 10-year time period, in Mexican women. METHODS: 72 women between 11 and 58 years old with unilateral ovarian cancer in different stages were studied. Several methods were analyzed: (1) progression-free survival, using Mantel and Haenzsel test to compare in terms of life curves and the Kaplan-Meier method. The exposure variable was surgery type, using the Mantel-Cox test to evaluate the difference in life curves by clinical stages and by surgery type; (2) fertility was evaluated in women who received conservative surgery, considering the cumulative pregnancy rate in women successfully pregnant after surgical and/or adjuvant treatment. RESULTS: There were no difference in survival curves when evaluating progression-free survival, in either group (Z = 1.09 and Pr > (z) = 0.27). During the study period, we found that 87.5% of patients were alive with no evidence of disease. There were no differences in survival curves when evaluating progression-free survival according to surgery type and clinical stage (chi 2 = 0.66, P = 0.88). Restart of menstruation in patients with conservative surgery occurred before 6 months in 89% of the sample, 22 women with possible parity had a 59.1% cumulative pregnancy rate. CONCLUSION: The outcomes from this survey carried out in Mexico show that conservative treatment of ovarian cancer in early clinical stages is an efficient alternative to preserve reproductive function in young women, and does not show differences in progression-free survival compared to radical surgery.

Adenocarcinoma↗

PubMed1997

The cervical cancer screening program in Mexico: problems with access and coverage.

A cross-sectional study was carried out in two geographic regions of Mexico - Oaxaca (rural area) and Mexico City (urban area) - to determine the main factors for predicting participation in Cervical Cytology Screening Programs (CCSP), in populations with high mortality due to cervical cancer. We included 4,208 women aged between 15 and 49 years, randomly selected through a national household-sample frame. Knowledge of what the Pap test is used for strongly predisposes use of CCSP in Mexico City (odds ratio [OR] = 46.1, 95 percent confidence interval [CI] = 33.1-64.1) and Oaxaca state (OR = 61.5, CI = 42.0-89.9), as well as high socioeconomic level (Mexico: OR = 2.0, CI = 1.1-7.6; Oaxaca: OR = 4.1, CI = 3.1-5.3), high education level (Mexico: OR = 3.6, CI = 1.5-8.8; Oaxaca: OR = 5.3, CI = 2.8-10.0), and access to social security (Mexico: OR = 1.7, CI = 1.4-2.2; Oaxaca: OR = 2.2, CI = 1.8-2.7). Low coverage of the CCSP is confirmed as an important problem in Mexico.

Adolescent↗

PubMed1997

Human papilloma virus 16-18 infection and cervical cancer in Mexico: a case-control study.

Cervical cancer (CC) is one of the principal public health problems in Mexico. The national mortality rate due to CC was estimated at 21.8 per 100,000 among women over 15 years old during 1994. Despite this high incidence little is known in Mexico about the risk factors for CC. The objectives of the study were to evaluate the association between CC and HPV types 16 and 18 in women living in Mexico City. From August, 1990 to December, 1992, a case-control study was carried out in the metropolitan area of Mexico City. HPV 16-18 types were determined in a sample of 148 CC cases and 204 controls randomly selected from a sample frame representative of the metropolitan area of Mexico City. Sixty cases corresponded to in situ CC and 88 cases to the invasive phase. Determination of HPV 16 and 18 types was done by polymerase chain reaction using primers specific to E6/E7. Results showed that 48.3% of in situ CC cases and 48.8% of invasive CC cases were positive for HPV 16 while only 13.2% were positive among the 204 controls. Association between HPV 16 infection in the in situ cancer cases had an estimated odds ratio (OR) of 5.17 (95% CI 2.60-10.51). In the invasive cervical cancer cases, association between HPV 16 infection and invasive CC in this sample had an OR of 3.84 (95% CI 2.04-7.22). For the total sample, the estimated OR was 5.48 (95% CI 3.07-9.62). In the total sample, those women with a strong positive reaction to PCR were associated with a large increase in the risk, OR of 38.0 (95% CI 8.66-167.1). The prevalence the HPV 18 was 6.7%, only observed in the invasive cervical cancer cases. At present there is general consensus that HPV is the principal causal agent in C C etiology. This study intends to contribute to the knowledge concerning the etiology of cervical cancer. However, it is necessary to consider that the single most effective tool in the reduction of mortality due to cervical cancer has been the Pap test. Secondary prevention has proven to be highly effective in other populations, and this should be viewed as a priority activity for all at-risk populations. Although a vaccine for HPV may be available in the near future its efficacy in primary prevention has yet to be demonstrated.

Adolescent↗

PubMed1996

Age of natural menopause among women in Mexico City.

OBJECTIVES: The average age of menopause among women in Mexico City was calculated, considering their reproductive and socio-demographic characteristics. The information was obtained from a population-based control group from a case-controlled study of gynecologic cancer. METHODS: Interviews were carried out with 1005 women resident in Mexico City chosen at random from a sample using the housing sample framework of the Mexico General Directorate of Epidemiology, 472 of whom had undergone a natural menopause. RESULTS: The most important results include an average age for menopause in this population of 46.5 +/- 5 years (95% C.I. 46-48) with a median of 47. Groups of women with an average early menopause were those with no formal education (1.6 years), low socio-economic level (1.3 years, P < 0.05), nulliparas (2.6 years, P < 0.05), those who had never breastfed (2.2 years, P < 0.05) and those who had not used contraceptive hormones (1.7 years, P < 0.05). CONCLUSION: This phenomenon must be documented in Mexico because of its strong links with the morbidity and mortality of the growing number of women who are reaching advanced ages and whose survival is calculated at 30 years after menopause.

Age Factors↗

PubMed1994

Quality control study on negative gynecological cytology in Mexico.

An external evaluation of the quality of diagnosis of gynecological cytology specimens (Papanicolaou or "Pap" tests) in the Cytopathological Laboratory at the Mexico General Hospital was performed, with evaluation of 6,011 Pap tests randomly selected from 31,378 Pap studies previously reported as negative during 1988-1989. These tests were part of the early detection program for cervical cancer run by the Ministry of Health of Mexico City. A quality index for specimens was constructed based on the presence of endocervical cells, mucus, and squamous metaplastic cells. The index of false negatives for the diagnosis of cervical neoplasm in this sample which correspond to diagnostic error by the examiner was 0.18% (11). The constructed quality index revealed that 64.1% of specimens were low quality. The correlation between diagnostic error and low quality was .87. Results indicate that laboratories participating in early detection programs for cervical cancer in developing countries need to implement (1) external evaluation programs for Pap diagnosis; (2) permanent training programs in registration; and (3) monitoring procedures for collection, fixation, and transportation of cytologic materials.

Adolescent↗

PubMedDate not supplied

Cervical cancer screening in developing countries: why is it ineffective? The case of Mexico.

BACKGROUND: Mexico established a national cervical cancer-screening program in 1974. Despite the implementation of the program, there was a steady mortality trend of 16 per 100,000 women over 15 years. METHODS: A diagnostic procedure of the pitfalls was applied to the following steps of the screening procedure: Pap sampling quality; cytological diagnosis validity; compliance of women; and determinants of non-participation. RESULTS: The low effectiveness of screening on cervical cancer is principally due to factors associated with quality and coverage. Pap quality is deficient; 64% of a random sample of specimens lacked endocervical cells. Reading centers presented false negative indices of between 10 and 54%. Women seek screening in a late stage of disease (55% with cervical cancer seek care because they have symptoms). In addition, coverage is low; in women between 15 and 49 years of age in Mexico City, 64.2% have a history of Pap, compared with 30% in rural areas. Knowledge of what the Pap is used for strongly determines the use of screening. In rural areas, only 40% of women are informed about the purpose of the Pap test. CONCLUSIONS: A proposal to reorganize Mexico's screening program includes the following five main strategies: (a) increased coverage; (b) improved quality control of how cervical smears are taken; (c) better interpretation of Pap tests; (d) guaranteed treatment for those whose tests show abnormalities, and (e) improved follow-up.

Adolescent↗

PubMedDate not supplied

Factors associated with non-epithelial ovarian cancer among Mexican women: a matched case-control study.

The purpose of this study was to identify risk factors associated with the development of non-epithelial ovarian cancer in Mexican women. A case-control study was carried out on women registered with the Mexican Institute of Social Security in Mexico City over a period of two years (1995-97). Twenty-eight new cases were recruited from the Gynecology and Obstetrics Hospital no. 4, "Luis Castelazo Ayala", and were matched by age with 84 controls selected randomly. Eighteen (64.3%) cases of germ cell tumors and 10 (35.7%) stromal sex cord tumors were found. The number of full term pregnancies was associated inversely to development of stromal sex cord tumors with lower risk in women with more than three full term pregnancies (odds ratio, 0.02: 95% confidence interval, 0.001-0.56) compared to nulliparous women. No associations were found respecting to germ cell tumors. Parity was inversely associated to development of stromal sex cord tumors, probably as a result of the endocrine system's influence on the ovaries. The development of germ cell tumors could be associated to factors not evaluated in this study.

Adolescent↗

PubMedDate not supplied

Validity and reproducibility of cytologic diagnosis in a sample of cervical cancer screening centers in Mexico.

OBJECTIVE: To evaluate the diagnostic precision of the cervical cytology (smear) in a sample of 16 cervical cancer screening centers (CCSCs) from the Mexican Ministry of Health and Mexican Institute for Social Security CCSCs distributed across the country. STUDY DESIGN: Each center received a batch of 90 cytologic specimens with a random positive prevalence of 1.5-36%. Positive cases were always histologically confirmed. The "gold standard" was an expert pathologist certified by the Mexican Board of Pathology. RESULTS: Our results show that cytologic diagnosis validity and reproducibility vary greatly within and between institutions. The false negative rate (FNR) varied between 10% and 54%, independent of the prevalence of positive cases. CONCLUSION: Quality control of diagnostic precision is central to the consistency of results obtained at CCSCs. In Mexico the high FNR calls for governmental regulation of cytopathology policies and methods, such as through national and international accreditation of cytotechnology programs. In order to decrease the FNR, developing countries must frame managerial development strategies to streamline the cervical cancer screening program, including continuing education, improvement of operation processes in CCSCs, internal and external quality control of cytopathology laboratories and cervical sampling procedures, and standardization of diagnostic criteria.

Evaluation Studies as Topic↗