Exploitation of stem cell homing for gene delivery.

Stem cells have been the focus of numerous investigations to treat diseases as far ranging as diabetes, chronic heart failure and multiple sclerosis over the past decade. The process of stem-cell-based repair of acute injury involves homing and engrafting of the stem cell of interest to the site of injury followed by either differentiation of the stem cell to indigenous end-organ cells or liberation of paracrine factors that lead to preservation and/or optimization of organ function. Recognition of the ability of stem cells to home to sites of acute injury suggests that, if appropriately defined and harnessed, stem cell homing could serve as a means of local drug delivery through the infusion of genetically engineering stem cells that secrete gene products of interest. The authors have recently demonstrated the use of this approach in preclinical studies of acute myocardial function. In addition, the use of engineered cells that home to appropriate niches have been used to correct genetic deficiency states (i.e., severe combined immunodeficiency, diabetes mellitus) in patients with otherwise chronic debilitating diseases. This review focuses on exploiting stem cell homing for gene transfer and on the state of the art and the challenges that face the field.

Trends in epidemiology and management of breast cancer in developing Arab countries: a literature and registry analysis.

BACKGROUND: Registries and research on breast cancer in Arabic and developing countries are limited. METHODS: We searched PubMed, Medline, WHO and IAEA publications, national, regional, hospital tumor registries and abstracts. We reviewed and analyzed available data on epidemiological trends and management of breast cancer in Arab countries, and compared it to current international standards of early detection, surgery and radiation therapy. RESULTS: Breast cancer constitutes 13-35% of all female cancers. Almost half of patients are below 50 and median age is 49-52 years as compared to 63 in industrialized nations. A recent rise of Age-Standardized Incidence Rates (ASR) is noted. Advanced disease remains very common in Egypt, Tunisia, Saudi Arabia, Syria, Palestinians and others. Mastectomy is still performed in more than 80% of women with breast cancer. There are only 84 radiation therapy centers, 256 radiation oncologists and 473 radiation technologists in all Arab countries, as compared with 1875, 3068 and 5155, respectively, in the USA, which has an equivalent population of about 300 million. Population-based screening is rarely practiced. Results from recent campaigns and studies show a positive impact of clinical breast examination leading to more early diagnosis and breast-conserving surgery. CONCLUSIONS: Breast cancer is the most common cancer among women in Arab countries with a young age of around 50 years at presentation. Locally advanced disease is very common and total mastectomy is the most commonly performed surgery. Awareness campaigns and value of clinical breast examination were validated in the Cairo Breast Cancer Screening Trial. More radiation centers and early detection would optimize care and reduce the currently high rate of total mastectomies. Population-based screening in those countries with affluent resources and accessible care should be implemented.

Effects of young age at presentation on survival in breast cancer.

BACKGROUND: Young age remains a controversial issue as a prognostic factor in breast cancer. Debate includes patients from different parts of the world. Almost 50% of patients with breast cancer seen at the American University of Beirut Medical Center (AUBMC) are below age 50. METHODS: We reviewed 1320 patients seen at AUBMC between 1990 and 2001. We divided them in three age groups: Below 35, 35-50, and above 50. Data and survival were analyzed using Chi-square, Cox regression analysis, and Kaplan Meier. RESULTS: Mean age at presentation was 50.8 years. 107 patients were below age 35, 526 between 35-50 and 687 patients above age 50. Disease stages were as follows: stage I: 14.4%, stage II: 59.9%, stage III: 20% and stage IV: 5.7%. Hormone receptors were positive in 71.8% of patients below 35, in 67.6% of patients 35-50 and in 78.3% of patients above 50. Grade of tumor was higher as age at presentation was lower. More young patients received anthracycline-based adjuvant chemotherapy. Of hormone receptor-positive patients, 83.8% of those below age 35 years, 87.76% of those aged 35-50 years, and 91.2% of those aged above 50 years received adjuvant tamoxifen. The mean follow up time was 3.7 +/- 2.9 years. Time to death was the only variable analyzed for survival analysis. Excluding stage IV patients, tumor size, lymph node, tumor grade and negative hormone receptors were inversely proportional to survival. Higher percentage of young patients at presentation developed metastasis (32.4% of patients below 35, as compared to 22.9% of patients 35-50 and 22.8% of patients above 50) and had a worse survival. Young age had a negative impact on survival of patients with positive axillary lymph nodes, and survival of patients with positive hormonal receptors, but not on survival of patients with negative lymph nodes, or patients with negative hormonal receptors. CONCLUSION: Young age at presentation conferred a worse prognosis in spite of a higher than expected positive hormone receptor status, more anthracycline-based adjuvant chemotherapy and equivalent adjuvant tamoxifen hormonal therapy in younger patients. This negative impact on survival was seen in patients with positive lymph nodes and those with positive hormonal receptors.