Qat Chewing and Risk of Potentially Malignant and Malignant Oral Disorders: A Systematic Review.

BACKGROUND: Qat (also known as Khat, Kat and Miraa) is a green-leaved plant (Catha edulis). It is a shrub indigenous to Yemen and certain parts of eastern Africa. Chewing the leaves, which have sympathomimetic and euphoric effects, has been documented in many countries and increased with worldwide migration. The effect of long-term chewing Qat on the oral cavity is unknown. OBJECTIVE: A systematic review was performed to identify any associations between Qat chewing and the occurrence of potentially malignant and malignant oral disorders. METHODS: Medline and the Web of Science were searched for articles published before May 2014 without limits with regard to publication date and language. RESULTS: From a total of 890 papers identified, 17 English papers reported potentially malignant or malignant oral disorders and Qat chewing. One additional paper in Arabic language was identified from reviewing the list of references of eligible papers. It was found that exposure to Qat may be associated with potentially malignant and malignant oral disorders, but methodological issues, such as inadequate study design, sample size, selection of study subjects, clinical evaluations of outcome and limited adjustment for confounders, limit the strength of the evidence base in this area. CONCLUSION: The association between Qat chewing and potentially malignant and malignant oral disorders remains debatable and requires further investigations.

The association between different night shiftwork factors and breast cancer: a case-control study.

BACKGROUND: Research on the possible association between shiftwork and breast cancer is complicated because there are many different shiftwork factors, which might be involved including: light at night, phase shift, sleep disruption and changes in lifestyle factors while on shiftwork (diet, physical activity, alcohol intake and low sun exposure). METHODS: We conducted a population-based case-control study in Western Australia from 2009 to 2011 with 1205 incident breast cancer cases and 1789 frequency age-matched controls. A self-administered questionnaire was used to collect demographic, reproductive, and lifestyle factors and lifetime occupational history and a telephone interview was used to obtain further details about the shiftwork factors listed above. RESULTS: A small increase in risk was suggested for those ever doing the graveyard shift (work between midnight and 0500 hours) and breast cancer (odds ratio (OR)=1.16, 95% confidence interval (CI)=0.97-1.39). For phase shift, we found a 22% increase in breast cancer risk (OR=1.22, 95% CI=1.01-1.47) with a statistically significant dose-response relationship (P=0.04). For the other shiftwork factors, risks were marginally elevated and not statistically significant. CONCLUSION: We found some evidence that some of the factors involved in shiftwork may be associated with breast cancer but the ORs were low and there were inconsistencies in duration and dose-response relationships.

Breast cancer among Yemeni women using the National Oncology Centre Registry 2004-2010.

BACKGROUND: In developing countries including Arab countries breast cancer is one of the most common cancers found in women. Even though breast cancer incidence is lower in Arab developing countries than in western countries, Arabic women are more likely to be diagnosed at an earlier age than the women in western countries. METHOD: A descriptive study was undertaken to investigate the type of breast cancer, lymph node involvement, side of breast and, region and age distribution of breast cancer patients registered in the National Oncology Centre in Yemen. RESULTS: From September 2004 to December 2010, 2654 women across Yemen diagnosed with breast cancer were registered in the National Oncology Centre for treatment. Between the years 2004 and 2010, breast cancer represented 22% of all cancers registered in women. Seventy-one per cent of the women were aged 50 or younger at the time of diagnosis. The most common age group affected was women aged 41-50 years, with (35%) of cases occurring in this age. Invasive ductal carcinoma was the most common pathology (76%) and 79% of the patients had lymph node involvement at the time of diagnosis. Approximately 2% had bilateral disease and the frequency of left (44%) and right breast cancer (42%) were similar. CONCLUSION: This study has shown that breast cancer is a disease of young women in Yemen. The majority of women presented with lymph node involvement. Hence efforts are needed to increase breast cancer awareness in Yemen for early detection at all age groups, and to target women living in areas that have lower access to health care services.