Dietary factors and endometrial cancer risk. Results of a case-control study in Mexico.

Daily diet factors that could potentially be related to endometrial cancer (EC) in Mexico are still unknown. This study aims to evaluate the association between EC and Mexican dietary factors. A case-control study in Mexico City was conducted during 1995-1997 in a social security hospital, using 85 incident cases of EC and 629 controls. A validated questionnaire with 116 items about the frequency and type of food intake was used. The analysis of nutrients was performed using the residual method, adjusting by predictor variables through logistic regression methods. In addition, partitional models estimated total caloric intake for other sources. We found no association between EC risk and consumption of animal or vegetable proteins, saturated, monounsaturated, or polyunsaturated fat, although high intake of nutrients such as lactose (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.21-1.01, P for trend = 0.004), vitamin D (OR, 0.38; 95% CI, 0.18-0.82, P= 0.003), and calcium (OR, 0.39; 95% CI, 0.17-0.89, P= 0.02) were inversely associated with EC. Our results suggest that dietary vitamin D and calcium play an important role in the development of EC, although the mechanisms postulated should be explained with additional studies with large populations.

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.

Prognostic factors related to cervical cancer survival in Mexican women.

OBJECTIVE: To identify prognostic survival factors among Mexican women with cervical cancer. METHODS: A total of 378 women with cervical cancer admitted from 1984 to 1996 to our referral hospital were evaluated, using survival analysis (Kaplan-Meier and Cox proportional hazards method). We designed a symptom index which included asymptomatic conditions, severity of symptoms and comorbidity. RESULTS: Overall 5-year survival was 66.6%. The shortest survival time was for FIGO stage IV (21.5%, P<0.001) and adenosquamous histologic type (53.1%, P=0.15). The main prognostic factors were primary symptoms (RR, 2.6; 95% CI, 1.02-6.66); systemic symptoms (RR, 3.3; 95% CI, 1.23-9.01); FIGO stage IV (RR, 5.5; 95% CI, 2.36-12.96); and oncogenic symptoms (prognostic comorbidity present) (RR, 2.3; 95% CI, 1.08-4.89). CONCLUSIONS: Our findings show that clinical stage and several types of symptoms influence CC survival. This present strategy to assess morphological and clinical characteristics may be a more accurate indicator of survival rate and potentially an efficient indicator of new therapeutic alternatives.

Asian-American variants of human papillomavirus 16 and risk for cervical cancer: a case-control study.

BACKGROUND: Human papillomavirus 16 (HPV16) has a number of variants, each with a different geographic distribution and some that are associated more often with invasive neoplasias. We investigated whether the high incidence of cervical cancer in Mexico (50 cases per 100 000 women) may be associated with a high prevalence of oncogenic HPV16 variants. METHODS: Cervical samples were collected from 181 case patients with cervical cancer and from 181 age-matched control subjects, all from Mexico City. HPV16 was detected with an E6/E7 gene-specific polymerase chain reaction, and variant HPV classes and subclasses were identified by sequencing regions of the E6 and L1/MY genes. Clinical data and data on tumor characteristics were also collected. All statistical tests were two-sided. RESULTS: HPV16 was detected in cervical scrapes from 50.8% (92 of 181) of case patients and from 11% (20 of 181) of control subjects. All HPV16-positive samples, except one, contained European (E) or Asian-American (AA) variants. AA and E variants were found statistically significantly more often in case patients (AA = 23.2% [42 of 181]; E = 27.1% [49 of 181]) than in control subjects (AA = 1.1% [two of 181]; E = 10% [18 of 181]) (P<.001 for case versus control subjects for either E or AA variants, chi2 test). However, the frequency of AA variants was 21 times higher in cancer patients than in control subjects, whereas that ratio for E variants was only 2.7 (P =.006, chi2 test). The odds ratio (OR) for cervical cancer associated with AA variants (OR = 27.0; 95% confidence interval [CI] = 6.4 to 113.7) was higher than that associated with E variants (OR = 3.4; 95% CI = 1.9 to 6.0). AA-positive case patients (46.2 +/- 12.5 years [mean +/- standard deviation]) were 7.7 years younger than E-positive case patients (53.9 +/- 12.2 years) (P =.004, Student's t test). AA variants were associated with squamous cell carcinomas and adenocarcinomas, but E variants were associated with only squamous cell carcinomas (P =.014, Fisher's exact test). CONCLUSIONS: The high frequency of HPV16 AA variants, which appear to be more oncogenic than E variants, might contribute to the high incidence of cervical cancer in Mexico.

Factors associated with non-use of Pap test. A population survey.

BACKGROUND: Cervical cancer is the most important cancer in Mexican women. Early detection is possible by means of the Papanicolaou (Pap) test; however, the coverage in Mexico is low. METHODS: A cross-sectional survey was carried out in a representative sample of women from the Tlalpan area of Mexico City. Social, reproductive and health care factors associated with the lack of use of the Pap test with respect to adequate use and misuse were identified. Both bivariate and logistic regression analyses were used for the adjustment of variables. RESULTS: Of 1,215 women studied, 22.5% had never had a Pap smear, 42% had misused the test (< 90% of triennial performance), and 35.5% had adequately used the test (> or = 90% of triennial performance). The main factors related to the lack of use were the following: not knowing about the Pap test (ORa = 35.16, 95% C.I. = 17.4-70.9); having fewer than 6 years of education (ORa = 4.5, 95% C.I. = 2.5-8.4); women younger than 30 years of age (ORa = 3.4 95% C.I. = 2.3-5.1); use of contraceptives (ORa = 0.4, 95% C.I. = 0.2-0.8); history of sexually transmitted diseases (ORa = 0.3, 95% C.I. = 0.1-0.8), and the principal informant about the Pap test, i.e., the health services personnel (ORa = 0.02, 95% C.I. = 0.0008-0.05). CONCLUSIONS: The lack of use and the misuse of Pap smears vary importantly among the different social and reproductive factors. But the principal reasons for lack of use were not knowing about the Pap test and a low educational level. We propose a greater diffusion on the benefits of the test in the Mexican population, through massive means of communication and health services.

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.

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.

[Reproductive risk factors and sexual history associated with cervical cancer in Mexico]. / Factores de riesgo reproductivo e historia de vida sexual asociados a cáncer cervical en México.

Uterine cervical cancer is one of the principal public health problems in Mexico. The national mortality rate for cervical cancer in 1991 is estimated at 9.5 per 100,000 women, representing 4,194 deaths. In the period from August 1990 to December 1992, a case-control study was carried out that included 630 cases of histologically confirmed cervical cancer in eight Mexico City hospitals (two for people with no social security cover, four of the social security system and two private). As controls, 1,005 women were chosen from a random sampling of houses in the Mexico City metropolitan area. The main cervical cancer risk factors found in this study, adjusted for a multivariate model, were multiple normals births (with five births OR of 1.93 and 95% C.I. of 1.22-2.73) and a history of two or more sex partners (the OR with four or more sex partners was 5.56 and a C.I. of 2.3-13.4). In addition, there was an estimated lower risk of disease related to starting a sex life after 25 years of age (OR 0.41 with C.I. of 0.25-0.69) and to having cesareans as compared versus one normal birth (OR 0.28 and C.I. of 0.13-0.61). The information obtained is relevant since it identifies Mexican women with a high-risk of developing cervical cancer which can be used in planning programs for the early detection of cancer in this population.

[Cervix carcinoma with endometrial and myometrial involvement. Report of a case]. / Carcinoma de cervix con extensión endometrial y miometrial. Presentación de un caso.

Cervical carcinoma extending to endometrium, and even more, to myometrium is very rare. At the present time there are only 28 reported cases in the literature, and 31 as primary of endometrium. The diagnosis of this condition requires strict histological criteria. The prognosis is bad. Surgery continues as the main therapeutic resource; the adjunt radiotherapy does not improve survival, and experience with chemiotherapy is limited.

Univariate and multivariate analysis of risk factors for ovarian cancer: case-control study, Mexico City.

Female residents of the southern part of Mexico City diagnosed with epithelial ovarian cancer between 1989 and 1992 (n = 172) were interviewed regarding reproductive events. The same information was obtained from the controls (n = 441). There was an elevated risk for ovarian cancer associated with an increased number of abortions, relative risk = 3.66 (95% confidence interval = 1.02 - 13.45) for women with four fetal losses. Ovarian cancer risk was shown to decrease as parity increased, reaching a relative risk of 0.23 (95% confidence interval = 0.09 - 0.55) in women with four or more live births in the postmenopausal group. This negative association seems less evident in overall cases. Logistic regression methods were used and abortions and high estimated number of ovulatory cycles were found to be associated with an increased risk of ovarian cancer. The inclusion of nonreproductive variables such as educational status, in the logistic model, showed that cases had a lower educational level than that of controls.

[Microinvasive cervico-uterine cancer. Diagnosis and treatment]. / Cáncer cervicouterino microinvasor. Diagnóstico y tratamiento.

This is a retrospective review of 63 patients with diagnosis of microinvasive cervical carcinoma. Diagnostic methodology included etiology, colposcopy, biopsy and cervical conization. Study parameters were: age, symptomatology, type of treatment and survival. The treatment to be established was chosen according to adverse prognostic factors, such as invasion depth, lymphovascular permeation, invasion pattern. The patients with an invasion depth up to 1 mm (IA1, FIGO) may be conservatively treated by cervical conization, if fertility is to be kept; there is risk of metastasis or recurrence. The patients with invasion of 1 to 5 mm (IA2, FIGO) may have a greater risk of recurrence and lymph node disease; the treatment should be individualized. There are no specific colposcopic data about microcarcinoma, and because of that, diagnostic precision is not high; however, colposcopy shows the adequate site for biopsy sampling, identifies vaginal extension areas and may influence the treatment.