The RANK/RANKL/OPG System in Tumorigenesis and Metastasis of Cancer Stem Cell: Potential Therapeutic Targets for Anticancer Therapy

Abstract

Background: The global burden of cancer continues to increase largely because of the aging and growth of the world population alongside an increasing adoption of cancer-causing behaviors, particularly smoking, in economically developing countries. Cancer (CA) is an increasing public health burden for Ethiopia and Sub- Saharan Africa at large. In Ethiopia, hospital records show that there are more than 150,000 cancer cases per year and currently cancer accounts for 4% of all deaths. Objective: The present prospective cross-sectional study was designed to assess the prevalence of cancer and its associated risk factors in patients visiting Tikur Anbessa Specialized Hospital (TASH). Methods: A prospective cross-sectional study was carried out in patients of all age groups visiting oncology unit of TASH during the study period of November 2015 to June 2016. Sample size was computed using margin of error 5%, confidence level of 95% and estimating cancer patients visiting TASH per annum equal to 20000. The response distribution was taken 10%, considering the 2012 Cancer Prevalence Report of the WHO in East Africa 5% to 10%. The calculated sample size then was 142. Result and discussion: The mean age of the participants in our study was 42.27 year with a standard deviation of 16.8, and 2 and 86 years were the age range. More than half of the patients in the study (61.3%, n=87) were females and about (38.7%, n=55) were males. In the study area uterine, breast, cervical, colorectal and gastric CA were more prevalent in the age group between 25-49 years while Acute Lymphoblastic Leukemia (ALL) was more common in 13-18 years of age, Ewing sarcoma was seen in age between 19 and 24 years. In our findings, breast CA (14.8%, n=21) was the most frequent type of CA followed by uterine CA (14.1%, n=20), colorectal CA (11.3%, n=16), gastric cancer CA (7.7%, n=11), cervical and esophageal cancers (7%, n=10). ALL was commonly seen in students, while gastric, lung, AML, osteosarcoma; and squamous cell CA were common in farmers. Furthermore, among 20 patients who had breast CA, 65% (n=13) were used contraceptives at least once in their last 10 years period, while uterine cancer patients (40%, n=8) were used either oral or injectable contraceptives. The prevalence of breast CA was not affected by the duration of contraceptive use rather it was stable across the duration of use. Many patients who were developed colorectal CA 12 (8.5%) and gastric CA 9 (6.3%) were reported that they were regularly consuming uncooked red meat as their favorite meal. In our study, many patients were receiving radiation therapy for cases such as uterine, breast, cervical and colorectal CA while chemotherapy was predominantly used in cases such as colorectal, squamous cell, osteosarcoma, ALL, AML and lung cancer. The multinomial regression analysis result further revealed that there was a significant association between breast CA with age (25-49 year, P. value 0.016), Uterine and Cervical CA with gender (female, P. value 0.001); and eating of uncooked red raw meat with colorectal CA (P. value 0.011). Conclusion: Cancer prevalence in the study area looks greatly jeopardizing the life of many Ethiopians in association with life styles. Hence, further studies should be done. Awareness creation programs to the people, allocation of public health preventive medicine approaches and in-depth governmental involvement in the area are highly needed.