Basic and Clinical Cancer Research
Volume:5 Issue: 1, Winter-Spring 2013

Migrant studies offer a unique opportunity to analyze variation in disease occurrence due to background factors. The role of environmental and lifestyle exposures are of particular interest in cancer research, and migrant studies can be considered as natural experiments in epidemiological research. Large numbers of immigrants from different regions of the world and the availability of comprehensive demographic and health-related registers in Sweden have prompted us to conduct migrant studies on the epidemiology of cancer. Breast cancer and genital tract cancers were selected for study since the role of environmental and lifestyle risk factors are debated for these disorders. To compare the risk and survival of the female breast, cervical, ovarian and endometrial cancers and male prostate and testicular cancers among immigrants to those among Swedish-born individuals to elucidate the importance and the potential timing of environmental and genetic factors in cancer etiology. We established different cohorts by linkages between Swedish national registers, including Cancer and Cause of Death registers, through personal identity number. The main exposure variable was country of birth with Swedish-born persons with both parents born in Sweden as reference group. Each cohort was followed from start date of follow-up period, date of birth or first immigration date, whichever occurred last, until exit date from the cohort, which was diagnosis of primary outcomes of interest, first emigration, or end of follow-up, whichever came first. We calculated incidence rate ratios and hazard ratios with 95% confidence intervals adjusted for age and calendar period of follow-up using Poisson and Cox proportional hazards regression models. First-generation immigrants in Sweden had an overall lower risk of cancers studied compared with Swedish-born people. However, we found remarkable variations in cancer risks and survival by country of birth. Age at immigration and duration of residence of first-generation immigrants were important factors affecting risk of cervical, breast, prostate, and testis seminomas. An increasing trend in incidence of prostate cancer among first-generation immigrants similar to either Sweden or country of birth was observed. Secondgeneration immigrants showed a risk converging toward the risk in Sweden for testicular and breast cancers. Education, as an indicator of socio-economic position, differentially affected the risk of cervical cancer among first-generation immigrants and Swedish-born women. Among both immigrants and Swedish-born women, breast cancer risk increased, while its mortality decreased with increasing level of education. Country of birth was a major determinant for cancer risk. Variation of risk by age at immigration or duration of residence highlights the effect of environmental and lifestyle factors on cancer risk. The observed patterns of prostate cancer risk imply the importance of both genetic and environmental factors in the etiology of this cancer. Patterns of testicular cancer risk indicate the importance of early environmental risk factors acting even after the intrauterine period.

The aim of this study was to investigate the epidemiological features of colorectal cancer in Imam Reza hospital in Kermanshah, Iran, in a five-year period.

This cross-sectional study included all the patients (N=167) admitted to Imam Reza hospital in Kermanshah over a five-year period, diagnosed with colorectal cancer through performing colonoscopy and confirming via pathology. The census sampling was applied, and the data collection tool was a questionnaire on demographic variables, smoking history, and family history of cancer in immediate relatives. The data were analyzed using the descriptive statistics of frequencies and ratios, and the statistical tests of t-test and chi-square.

The mean age of the patients was 58.67±14.31 years old (14-87 years), and 12 % of the patients were under 40 years old. The majority of the patients (52.1%) were males, but no significant difference was found between the two genders in terms of age (P=0.939). The rectum (31.1%), the sigmoid colon (20.4 %), and the ascending colon (18.6%) were the most common tumor sites. Colon adenocarcinoma (96.4%) was the most common reported pathology, 30.5 % of the patients were cigarette smokers, and abdominal pain (22%) was the most common complaint on admission.

Given the results of the present study, it is highly recommended that comprehensive studies should be conducted on screening colorectal cancer in high risk populations in order to reduce the incidence and prevalence of the disease and treat it more effectively based on early diagnosis.

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors. Its incidence is rated as one among the highest in the world and the use of tobacco in various forms is increasingly associated with the cause of OSCC. In oral cancer the study of tumor markers have been limited and several tumor makers with clinical promise needs further evaluation. Present study was conducted in histopathologically confirmed OSCC patients form Coimbatore city, South India. Levels of β2-Microglobulin and Total Sialic Acid (TSA) in serum of the subjects were analyzed by ELISA and spectrophotometric method. The levels of β2-microglobulin (3.81±0.09) and TSA (72.81±2.31) were found to be elevated in OSCC patients when compared with the controls (2.07±0.15; 64.17±1.86). Mean values were compared between the smokers and non smokers, which showed a significant increase in the level of β2-microglobulin and TSA (P < 0.05). In this study, the levels of β2-microglobulin and TSA were higher in OSCC patients with smoking habit than in non smokers. The study hypothesizes that this imbalance may be one of the major factors responsible for the progression of oral cancer.

Background of the study: Colorectal cancer (CRC) which is the third most diagnosed cancer throughout the world is steadily rising in the Asian countries with the incidence rates mimicking the western counterparts. The pre-neoplastic nature of the Transitional Mucosa (TM) adjoining CRC lacks conclusive evidence so far. Pertaining to this, the study of the mucus layer, the functional component of the colonic mucosa overlying the TM is the subject of interest in this research. The normal samples were biopsied from normal subjects by colonoscopy. Ten cases of CRCs of the distal colon who underwent anterior resection were chosen for this study. Three samples were taken 2ms, 5cms and 10cms from the colorectal cancer of the distal colon in the proximal margin. These samples were processed and viewed under the scanning electron microscope (SEM) to look for the changes in the mucus layer. The findings show that the changes were consistently found 2cms from the tumor and only one case showed changes up to 5cms. The statistical tests using SPSS version 18 revealed that there was no association between the surface mucus changes and the age, gender, race, site of tumor, differentiation of tumor and clinical staging of the patients. It was concluded that there was no correlation between the structural and functional changes of the surface mucus overlying the distal colon during carcinogenesis. Furthermore, it can be stated that the functional change may be as a result of the structural change due to a nearby tumor.

Background and Today, one of the major health problems worldwide is cancer. Several factors are involved in cancer incidence; however, the role of environmental factors is more prominent. Modifying these factors and changing them into proper behavior can have a fundamental role in preventing cancer. Accordingly, this study was conducted to evaluate the exposure to carcinogenic agents in Tehran citizens. This descriptive cross-sectional study was conducted on a sample size of 2500 Tehran citizens who were selected by cluster random sampling. Data collection instrument was a questionnaire with five parts including demographic information, and questions regarding alcohol and tobacco use, exposure to radiation, chemicals, and reaction to stressors. Data were collected at one time and in person. Data analysis was performed by SPSS software (v. 11.5) and descriptive statistics. Results showed that 10.4% of the sample consumed alcohol, 16% smoked cigarette and hookah, 22% of the subjects were always exposed to sunlight, 88.4% had no contact with chemicals at work place and 94.4% were not taking hormone during menopause and the majority of subjects (45.8%) got angry sometimes. Most of Tehran Citizens are exposed to carcinogenic agents, especially radiation, cigarette smoke, chemicals and with less intensity with stressors. Due to the fact that alcohol is prohibited in Islam, no clear information is available about its consumption. It is helpful to educate people about the carcinogenic agents.