The prevalence of BRCA1 and BRCA2 mutations among young Mexican women with triple-negative breast cancer.

Various guidelines recommend that women with triple-negative breast cancer should be tested for BRCA1 mutations, but the prevalence of mutations may vary with ethnic group and with geographic region, and the optimal cutoff age for testing has not been established. We estimated the frequencies of BRCA1 and BRCA2 (BRCA) mutations among 190 women with triple-negative breast cancer, unselected for family history, diagnosed at age 50 or less at a single hospital in Mexico City. Patients were screened for 115 recurrent BRCA mutations, which have been reported previously in women of Hispanic origin, including a common large rearrangement Mexican founder mutation (BRCA1 ex9-12del). A BRCA mutation was detected in 44 of 190 patients with triple-negative breast cancer (23 %). Forty-three mutations were found in BRCA1 and one mutation was found in BRCA2. Seven different mutations accounted for 39 patients (89 % of the total mutations). The Mexican founder mutation (BRCA1 ex9-12del) was found 18 times and accounted for 41 % of all mutations detected. There is a high prevalence of BRCA1 mutations among young triple-negative breast cancer patients in Mexico. Women with triple-negative breast cancer in Mexico should be screened for mutations in BRCA1.

Overweight and obesity as poor prognostic factors in locally advanced breast cancer patients.

Obesity and overweight are established risk factors for the development of breast cancer. They are also associated with poor prognosis for higher risk of disease recurrence and lower overall survival (OS). The aim of this study was to evaluate the influence of overweight and obesity in OS in patients with locally advanced breast cancer (LABC) treated with neoadjuvant chemotherapy. This is a retrospective analysis that included 819 patients diagnosed with LABC between January 2004 and December 2008. The patients were treated with neoadjuvant chemotherapy (NAT) based on anthracyclines, taxanes, or both, followed by surgery. For comparison, patients were divided into the normal weight (NW) group or the overweight/obesity (OW/OB) group. The prevalence of overweight/obesity was 74 %. General characteristics of the patients, including age, tumor size, clinical stage, nuclear grade, hormone receptors, and HER2 expression, were similar between both groups. At a median follow-up of 28 months, we found a statistically significant difference in OS between the two groups, achieving a 91.5 % in NW patients versus 85.9 % in the OW/OB group (P = 0.050). Cox multivariate analysis demonstrated that obesity was an independent factor for poor prognosis, with a hazard ratio of 1.79 (95 % CI (Confidence Interval) 1.09-2.96; P = 0.022). This is the first Mexican study that confirms the role of OW/OB as a risk factor for poor outcome among patients with LABC. Obesity in our country is a public health problem and requires strong preventive intervention strategies for its control, especially among patients diagnosed with breast cancer.

A Y/15 translocation in a 45,X male with Prader-Willi syndrome.

We report a male neonate with a 45 X karyotype; the long arm of a chromosome 15 was translocated onto the proximal long arm of the Y chromosome. Breakpoints were identified by in situ fluorescence hybridization (FISH) on the proximal 15q13 and Yq11.2. The derivative chromosome has no primary centromere. Clinical features were compatible with Prader-Willi syndrome. This is the first report case ofmonosomy 15q and Yq deletion with Prader-Willi syndrome.

Antimicrobial resistance and characterization of Helicobacter pylori strains isolated from Mexican adults with clinical outcome.

Eradication of Helicobacter pylori infection in Mexico is of great importance due to the elevated seroprevalence, however, there is yet very little information about antibiotic resistance rates in H. pylori isolates in our country. We analyzed susceptibility to three antimicrobials used in therapy of 49 H. pylori strains isolated from patients with active chronic gastritis, active chronic gastritis with lymphoid follicles, intestinal metaplasia and gastric cancer. All isolated strains were susceptible to amoxicillin, 28 (58%) were resistant to metronidazole and 2 (4%) were resistant to both clarithromycin and metronidazole. Sequence analysis of the 23S rRNA of the two clarithromycin-resistant strains showed the A2142G mutation in one and A2143G and T2182C mutations in the other. Metronidazole resistance was associated with cagA negative strains with a frequency of 82% (9/11). No significant correlation was found between vacA s/m alleles and metronidazole resistance.

A phase II study of multimodality treatment for locally advanced cervical cancer: neoadjuvant carboplatin and paclitaxel followed by radical hysterectomy and adjuvant cisplatin chemoradiation.

BACKGROUND: Our aim was to evaluate the efficacy and safety of neoadjuvant chemotherapy followed by radical hysterectomy and adjuvant radiation concurrent with weekly cisplatin for locally advanced cervical carcinoma. PATIENTS AND METHODS: Forty-three patients staged as IB2-IIIB were treated with three 21-day courses of carboplatin (area under the time-concentration curve 6 mg.min/ml) and paclitaxel at 175 mg/m(2) by 3-h infusion both on day 1 followed by radical type III hysterectomy and adjuvant radiation concurrent with 6-weekly doses of cisplatin at 40 mg/m(2). Response rate, resectability, toxicity and survival were evaluated. RESULTS: From December 2000 to June 2001, 43 patients were recruited. All were evaluated for response and toxicity to neoadjuvant chemotherapy. A total of 129 courses were administered. Clinical responses were seen in 41 patients (95%) [95% confidence interval (CI) 89.2% to 100%] with four (9%) complete and 37 (86%) partial. Forty-one patients underwent surgery (resectability 95%); pathologically complete or near-complete responses were seen in seven (17%) and eight (20%), respectively, positive surgical margins in five (12%), and positive pelvic lymph nodes in eight (20%). Twenty-six patients were scheduled for adjuvant chemoradiation. External radiation was delivered for 42.8 days (range 33-61), with a mean dose of 49.3 Gy (range 46-56), and a median of five cisplatin courses (two to six). The mean dose of brachytherapy was 32 Gy (range 25.5-35.6). Neoadjuvant therapy was well-tolerated with neutropenia grade 3 and 4 in 12% and 3% of the courses, respectively. Toxicity to adjuvant chemoradiation was mainly hematological and gastrointestinal, mostly grades 1/2. A total of 39 patients completed all scheduled treatment. At a median follow-up of 21 months (range 3-26), the projected overall survival in the intention-to-treat analysis was 79% (95% CI 62% to 88%). CONCLUSIONS: The triple modality of neoadjuvant chemotherapy followed by radical hysterectomy and adjuvant radiation concurrent with cisplatin is a highly active treatment for locally advanced cervical carcinoma with acceptable toxicity.

Concomitant chemoradiation versus neoadjuvant chemotherapy in locally advanced cervical carcinoma: results from two consecutive phase II studies.

BACKGROUND: Randomized studies comparing induction chemotherapy followed by surgical resection with radiation alone found that the neoadjuvant approach produces better results. So far, this latter modality has not been compared with standard concomitant chemoradiation. The objective of this report was to compare the results of two consecutive phase II studies: neoadjuvant chemotherapy followed by surgery or chemoradiation for the unresectable cases versus standard cisplatin-based chemoradiation. PATIENTS AND METHODS: From February 1999 to July 1999, 41 patients with cervical carcinoma, stages IB2-IIIB, were treated with neoadjuvant chemotherapy. Treatment consisted of three 21-day courses of cisplatin 100 mg/m(2) on day 1 and gemcitabine 1000 mg/m(2) on days 1 and 8, followed by either surgery or concomitant chemoradiation for the non-operable cases. From August 1999 to December 1999, an equal number of patients having comparable clinicopathological characteristics were treated with six weekly courses of cisplatin 40 mg/m(2) during standard pelvic radiation. RESULTS: A total of 82 patients were analyzed. Both groups were similar with regard to age, histology, International Federation of Gynecology and Obstetrics (FIGO) stage, tumor size, pretreatment hemoglobin levels, parametrial infiltration and performance status. In the neoadjuvant arm the overall response rate to induction chemotherapy was 95% (95% confidence interval 88% to 100%). Twenty-three patients had surgery and 14 underwent chemoradiation. In the definitive chemoradiation study, 38 patients completed treatment, the median number of cisplatin courses was six for a dose intensity of 33 mg/m(2)/week. Doses to points A and B were 85 Gy (range 68-95) and 55 Gy (range 51-65), respectively. Chemoradiation was delivered in 44.6 (range 28-113) days. Complete response rates after all treatment were similar: 97% and 87% in the neoadjuvant and chemoradiation groups, respectively. At a median follow-up of 28 (range 2-33) and 24 (range 3-30) months, respectively, there were no differences in overall survival. To date, 15 and 13 patients in the neoadjuvant and chemoradiation groups, respectively, have died of disease (P = 0.8567). CONCLUSIONS: The results of this non-randomized comparison suggest that induction chemotherapy followed by surgery or chemoradiation is at least as effective in terms of response and survival as standard cisplatin-based chemoradiation. A randomized study is needed to confirm these findings.

Intralesional vinblastine vs. 3% sodium tetradecyl sulfate for the treatment of oral Kaposi's sarcoma. A double blind, randomized clinical trial.

In this double-blind, randomized trial, we compared the clinical efficacy of intralesional vinblastine (VNB) and 3% sodium tetradecyl sulfate (STS) in the treatment of oral Kaposi's sarcoma (OKS). Subjects with OKS were randomly assigned to receive a single intralesional injection of either VNB or STS, at a standard dose (0.2 mg/cm(2)). Differences were evaluated by the Mann-Whitney U and Fisher's exact tests. Sixteen HIV-infected patients were included, eight received VNB and eight received STS; clinical response was evaluated at days 7, 14, and 28 following treatment. Tumor size reduction was 0.68 and 0.61 cm in the VNB and STS groups, respectively (P=0.80). Two VNB patients had complete or partial response whereas four STS subjects had partial responses (P=0.61). Patients in both groups experienced minimal toxicity. We conclude that intralesional vinblastine or STS are adequate for the management of OKS. The benefits of STS are its low cost and ease of use.

p53 Mutations in nasal natural killer/T-cell lymphoma from Mexico: association with large cell morphology and advanced disease.

Nasal NK/T-cell lymphoma is a unique form of lymphoma highly associated with Epstein-Barr virus, and with a characteristic geographic distribution. Recently, we showed that p53 is overexpressed in a high percentage of nasal NK/T-cell lymphomas. The aim of this study was to analyze the status of the p53 gene, and correlate it with the expression of p53 protein and its downstream target, the cyclin-dependent kinase inhibitor p21, in a series of 25 cases of well-characterized nasal NK/T-cell lymphoma from Mexico. The highly conserved exons 5 to 8 of the p53 gene were amplified by polymerase chain reaction and screened for mutations by denaturing high-pressure liquid chromatography. Abnormal polymerase chain reaction products detected by denaturing high-pressure liquid chromatography and additional selected cases were sequenced. In addition, the incidence of loss of heterozygosity at the p53 locus was analyzed in 12 cases. Of the 25 patients, 17 were male and 8 female (M:F ratio, 2.1:1), with a median age of 43 years (range, 21 to 93 years). Morphologically, most of the cases were composed of a mixture of medium-sized cells and large transformed cells (21 cases), and four cases were composed exclusively of large transformed cells. Three different groups determined by p53 gene status and expression of p53 protein were identified: group 1 was p53 +/p53 mutated (five cases, all with p53 missense mutations). Morphologically, three of the five cases were composed of large cells. All five cases revealed overexpression of p53 in the majority of the tumor cells with a mean of 86%. Unexpectedly, three of these cases also showed overexpression of p21. Four of the five patients presented with clinical stage IVB and died with disease. Group 2 was p53+/p53 wild-type (10 cases). Histologically, nine cases were of the mixed type, and one of the large cell type. The percentage of p53 overexpressing cells was lower than in the previous group with a mean of 23%. p21 was positive in 7 of the 10 cases. Six patients in this group presented with clinical stages I to II and four patients with advanced disease (stage III and IV). Five patients are alive 12 to 120 months later (mean, 24 months), three with no evidence of disease. Group 3 was p53-/p53 wild-type (10 cases). All cases showed mixed cell morphology. p21 was positive in 5 of 10 cases. Four patients presented with clinical stage I to II and six patients with advanced disease. Four patients are alive with no evidence of disease 9 to 60 months later (mean, 10 months). Overall, p53 mutations were present in 24% (5 of 21) of the evaluable cases, all of them overexpressing p53 in the majority of tumor cells. Cases with p53 mutations were associated with large cell morphology (P = 0.0162) and presented more often with advanced stage disease. Loss of heterozygosity at chromosome 17p was found only in 2 of the 12 (17%) cases investigated, both cases showed p53 mutations of the remaining allele. P21 overexpression (60% of cases) is frequent in nasal NK/T-cell lymphoma and seems to be independent of p53 gene status. The overexpression of p53 and p21, independent of p53 mutations, although as yet not clear, might be the result of Epstein-Barr virus infection, and warrants further investigation.

Type III radical hysterectomy after induction chemotherapy for patients with locally advanced cervical carcinoma.

Neoadjuvant chemotherapy followed by surgery is a promising approach in locally advanced cervical carcinoma. The aim of this study was to evaluate the feasibility, technical aspects, and clinical results of surgery after induction chemotherapy in this patient population. Forty-one untreated cervical carcinoma patients staged as IB2 to IIIB received three 21-day courses of cisplatin 100mg/m2 on day 1 and gemcitabine 1000 mg/m2 on days 1 and 8 followed by surgery or concomitant chemoradiation. The response to chemotherapy, operability, surgical/pathological findings, disease-free period, and survival of the surgically treated patients were evaluated. All 41 patients were evaluated for toxicity and 40 were evaluated for response. The overall objective response rate was 95% (95% confidence interval 88%-100%), and was complete in three patients (7.5%) and partial in 35 (87.5%). Granulocytopenia grades 3/4 occurred in 13.8% and 3.4% of the courses, respectively, whereas nonhematological toxicity was mild. Twenty-three patients underwent type III radical hysterectomy. Mean duration of surgery was 3.8 h (range 2:30-5:20), median estimated blood loss was 670 ml and median hospital stay was 5.2 days. Intraoperative complications occurred in one case (venous injury). In all but one case the resection margins were negative. Four patients (17%) had positive nodes (one node each); six (26%) had complete pathologic response, three (13%) had microscopic; and 14 (60%) macroscopic residual disease. At 24 months of maximum follow-up (median 20), the disease-free and overall survival rates were 59% and 91%, respectively. Induction chemotherapy with cisplatin/gemcitabine produced a high response rate and did not increase the difficulty of surgery. Operating time, blood loss, intraoperative complications, and hospital stay were all within the range observed for type III hysterectomy in early stage patients. We therefore conclude that type III radical hysterectomy is feasible in locally advanced cervical cancer patients who respond to chemotherapy.

High prevalence of oncogenic human papillomavirus in the genital tract of women with human immunodeficiency virus.

OBJECTIVE: The goal of this study was to determine the prevalence of human papillomavirus (HPV) and squamous intraepithelial lesions (SILs) in women infected with human immunodeficiency virus (HIV) in Mexico. METHODS: Cases included women who were positive for human immunodeficiency virus (HIV) and accepted to participate. There were two control groups in this study: group A, heterosexual partners of HIV+ men; group B, commercial sex workers. Gynecologic examination was performed in all participants. Also, a cervical smear with colposcopy and a sample for detection of HPV DNA by polymerase chain reaction (PCR) were obtained in all subjects, as were CD4+ counts. Relative risks (RR) and 95% confidence interval were calculated. RESULTS: Eighty-five HIV+ women agreed to participate in this study; the route of HIV infection was heterosexual in 78.8%; transfusion in 8.2%; paid donors in 3.5%; and 9.4% unknown. A total of 9 controls were included: 4 from group A and 5 from group B. HPV DNA was detected by PCR in 57 (69%) cases and in 26 (29%) controls from both groups (P < 0.0001). The RR of HPV infection was 5.5 (2.7-11.5). Also, a significant difference in the prevalence of high-risk HPV types was observed between cases and controls, RR = 12.8 (4.07-42.9). These associations were independent of CD4+ counts and antiretroviral therapy. No association was observed between HIV infection and the risk for high-grade SIL. CONCLUSIONS: We observed a high prevalence of oncogenic HPV types in HIV-positive women. These women should be screened regularly for early diagnosis of premalignant lesions and prevention of cervical cancer.

A phase II study of gemcitabine and cisplatin combination as induction chemotherapy for untreated locally advanced cervical carcinoma.

BACKGROUND: Cisplatin-based chemoradiation for locally advanced cervical carcinoma is now the standard of care for most patients with cervical carcinoma. However, induction chemotherapy followed by surgery, particularly with newer agents or combinations remains to be explored. This study was undertaken to evaluate the antitumor activity and toxicity of gemcitabine in combination with cisplatin for untreated locally advanced cervical carcinoma. PATIENTS AND METHODS: Open-label, single center, phase II, non-randomized study of neoadjuvant gemcitabine plus cisplatin. Forty-one patients with histologic diagnosis of cervical carcinoma, with no previous treatment and staged as IB2 to IIIB, were treated with three 21-day courses of cisplatin 100 mg/m2 day I and gemcitabine 1000 mg/m2 days 1 and 8, followed by locoregional treatment with either surgery or concomitant chemoradiation. Response and toxicity were evaluated before each course and at the end of chemotherapy. RESULTS: All patients were evaluated for toxicity and 40 for response. The overall objective response rate was 95% (95% confidence interval (CI): 88%-100%) being complete in 3 patients (7.5%) and partial in 35 (87.5%). A complete pathological response was found in 6 (26%) of the 23 patients that underwent surgery. Granulocytopenia grades 3-4 occurred in 13.8% and 3.4% of the courses, respectively, whereas non-hematological toxicity was mild. CONCLUSIONS: Induction chemotherapy with the combination of gemcitabine and cisplatin is highly active for untreated cervical cancer patients and has an acceptable toxicity profile.

Ki-67: a proliferative marker that may predict pulmonary metastases and mortality of primary osteosarcoma.

Alterations in Ki-67 activity have been associated with tumor progression and poor outcome in cancer patients. This study was undertaken to identify the potential of this proliferative marker as a predictor of pulmonary metastases (PM) and mortality in osteosarcoma patients. In 38 patients with tissue available for immunohistochemical analysis, overexpression of Ki-67 was assessed. Chi-square and log rank tests were used to determine differences between proportions of the marker with PM and mortality and survival distributions respectively. P values equal or less than .05 were considered statistically significant. The median follow up of this case series was 28 months. Eighteen (47.4%) of 38 patients developed PM, and 17 (44%) overexpressed Ki-67. We found a high frequency of PM (15 of 17) among those cases that overexpressed Ki-67. This relationship was significant (P = .000006) when compared to the rest of the group. We also found a statistically significant correlation between patients with positive and negative Ki-67 scores and higher and lower mortality (P = .000962). These findings suggest that Ki-67 overexpression could be used as a prognostic molecular marker for the development of PM in osteosarcoma patients.

Involvement of chemokine receptors in breast cancer metastasis.

Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. Tumour cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptors CXCR4 and CCR7 are highly expressed in human breast cancer cells, malignant breast tumours and metastases. Their respective ligands CXCL12/SDF-1alpha and CCL21/6Ckine exhibit peak levels of expression in organs representing the first destinations of breast cancer metastasis. In breast cancer cells, signalling through CXCR4 or CCR7 mediates actin polymerization and pseudopodia formation, and subsequently induces chemotactic and invasive responses. In vivo, neutralizing the interactions of CXCL12/CXCR4 significantly impairs metastasis of breast cancer cells to regional lymph nodes and lung. Malignant melanoma, which has a similar metastatic pattern as breast cancer but also a high incidence of skin metastases, shows high expression levels of CCR10 in addition to CXCR4 and CCR7. Our findings indicate that chemokines and their receptors have a critical role in determining the metastatic destination of tumour cells.

Gastric atrophy and extent of intestinal metaplasia in a cohort of Helicobacter pylori-infected patients.

Atrophy and intestinal metaplasia (IM) are preneoplastic gastric lesions associated with Helicobacter pylori infection. Atrophy and IM are usually found together; however, the association between increasing degrees of severity of both atrophy and IM has not been evaluated completely. Two pathologists graded atrophy and IM using the visual analog scale of the Sydney classification in gastric biopsies from 368 H pylori-infected patients. Extent of IM also included determining the number of specimens affected. We then correlated the degree of atrophy with the degree and number of specimens affected with IM by calculating relative risks (RR) and 95% confidence intervals (95% CI). The mean number of biopsies examined from each patient was 6.5. Atrophy and IM were found more frequently in the antrum (85% and 75% of biopsies, respectively). One hundred thirty-eight patients had a combination of atrophy and IM, 48 had IM only, and 89 had atrophy only. Fifty-three subjects had mild atrophy and IM (RR = 1.57; 95% CI 1.2-2.1), 69 had moderate atrophy and IM (RR = 1.86; 95% CI 1.9-2.4), and 16 had marked atrophy and IM (RR = 2.47; 95% CI 1.8-3.3). The median number of biopsy specimens with IM increased from 0 in subjects with no atrophy to 3 in subjects with severe atrophy. The degree of IM correlated with the degree of atrophy; the median degree was 0.6 in subjects with no atrophy and increased to 2.32 in those with severe atrophy. Our data suggest that higher degrees of IM in an individual specimen and increasing number of specimens with IM are associated with moderate or severe degrees of atrophy.

Screening markers for chronic atrophic gastritis in Chiapas, Mexico.

Intestinal-type gastric adenocarcinomas usually are preceded by chronic atrophic gastritis. Studies of gastric cancer prevention often rely on identification of this condition. In a clinical trial, we sought to determine the best serological screening method for chronic atrophic gastritis and compared our findings to the published literature. Test characteristics of potential screening tests (antibodies to Helicobacter pyloni or CagA, elevated gastrin, low pepsinogen, increased age) alone or in combination were examined among consecutive subjects enrolled in a study of H. pylori and preneoplastic gastric lesions in Chiapas, Mexico; 70% had chronic atrophic gastritis. English-language articles concerning screening for chronic atrophic gastritis were also reviewed. Sensitivity for chronic atrophic gastritis was highest for antibodies to H. pylori (92%) or CagA, or gastrin levels >25 ng/l (both 83%). Specificity, however, was low for these tests (18, 41, and 22%, respectively). Pepsinogen levels were highly specific but insensitive markers of chronic atrophic gastritis (for pepsinogen I <25 microg/l, sensitivity was 6% and specificity was 100%; for pepsinogen I:pepsinogen II ratio <2.5, sensitivity was 14% and specificity was 96%). Combinations of markers did not improve test characteristics. Screening test characteristics from the literature varied widely and did not consistently identify a good screening strategy. In this study, CagA antibodies alone had the best combination of test characteristics for chronic atrophic gastritis screening. However, no screening test was both highly sensitive and highly specific for chronic atrophic gastritis.

Prognostic factors on 45 cases of phyllodes tumors.

The authors, in order to obtain a diagnostic index for phyllodes tumors and identified histological parameters that will predict the clinical course of this neoplasm, developed a histological degree of aggressiveness based on specific histological parameters, including: stromal:gland ratio, tumor margins, mitotic index and degree of stromal pleomorphism. Three categories were established: benign, intermediate and malignant. The probability of recurrence was estimated by the relative risk and by a multivariate Cox analysis. A strong and significant association was observed between this histological index and recurrence. The relative risk was 6.0 for intermediate lesions and 11.4 for malignant lesions when compared with the benign category. The microscopic examination of all axillary lymph nodes was negative for metastatic disease. In the multivariate analysis, the stroma:gland ratio was the strongest predictor for recurrence. These results indicate that by assigning a numerical value to certain histopathologic variables a better correlation with the clinical outcome of the patient can be obtained.

Surgical site infections at the National Cancer Institute in Mexico: a case-control study.

OBJECTIVES: To quantify the surgical infection rate and to identify risk factors associated with surgical site infection. METHODS: We conducted a case-control study of all surgical patients between January 1, 1993, and June 30, 1994. The frequency of surgical site infection per 100 surgeries was calculated. The odds ratio (OR) was estimated by using logistic regression analysis. SETTING: A 130-bed tertiary-care teaching hospital for adult patients with cancer. RESULTS: The study followed 3372 surgeries. Three hundred thirteen patients had a surgical site infection (rate per 100 surgeries: 9. 30). The risk factors associated with surgical site infection were diabetes mellitus (OR = 2.5, 95% confidence interval [CI] = 1.27-4. 91), obesity (OR = 1.76, 95% CI = 1.14-2.7), presence of surgical drains for >5 and <16 days (OR = 1.84, 95% CI = 1.02-3.31), and presence of surgical drains for >/=16 days (OR = 2.14, 95% CI = 1. 0-4.6). The bacteria most frequently isolated were Escherichia coli 38 (21.8% of the total of microorganisms found), Pseudomonas sp 22 (12.6%), Staphylococcus aureus 16 (9.2%), and coagulase-negative Staphylococcus 25 (13.6%). The coexistence of other nosocomial infections was greater among the cases (OR = 1.8, 95% CI = 1.1-3.1) than in the control group. CONCLUSIONS: The surgical site infection rate in our hospital is slightly higher than the rates reported for general hospitals. The risk factors associated with surgical site infection are similar to those previously reported. Diabetes mellitus, obesity, and prolonged presence of a surgical drain increased the risk of infection.

[The association between Helicobacter pylori and gastric neoplasia. Epidemiologic evidence]. / La asociación entre Helicobacter pylori y neoplasias gástricas. Evidencia epidemiológica.

Helicobacter pylori (HP) causes chronic gastritis and, together with non-steroidal anti-inflammatory drugs, is considered the most frequent etiologic agent of peptic ulcer. Since there are numerous epidemiologic and pathogenesis studies that demonstrate an association between infection by HP and gastric neoplasias, the World Health Organization declared, in 1994, HP infection a Group 1 carcinogen (a definitive cause of human neoplasias, similar to tobacco). This article reviews the epidemiological evidence supporting the association between HP infection and two gastric neoplasias: adenocarcinoma and B cell lymphoma associated to mucosas (MALT). This article also presents preliminary results of a project performed in the mountainous region of Chiapas, Mexico, in which the decrease of precancerous gastric lesions were studied one year after treatment for HP infection.