CHAPTER ONE

1.0 INTRODUCTION

Cancer is a leading cause of death worldwide. An estimated 14.1million new cancer cases occurred in 2012 (GLOBOCAN, 2012). Lung, female breast, colorectal and stomach cancers accounted for more than 40% of all cases diagnosed worldwide (GLOBOCAN, 2012). In men, lung cancer was the most common cancer (16.7% of all new cases in men). Breast cancer was by far the most common cancer diagnosed in women (25.2% of all new cases in women), (Srijita-Dutta, 2015). Approximately, 32.5 million People diagnosed with cancer in 2008 were alive at the end of 2012. Most were women after their breast cancer diagnosis (6.3 million), men after their prostate cancer diagnosis (3.9 million), and men and women after their colorectal cancer diagnosis (3.5 million) (Popoola et al., 2013).

The incidence of colorectal carcinoma has been on the increase in the developing countries, including Nigeria, as a result of change in diet and adoption of western lifestyle (Echendu al., 2015). A total of 241 cases of colorectal carcinoma were reported, 144 cases (60%) in males and 96 cases (40%) in females with a male: female ratio of 1.5:1. The peak age of occurrence for males was between 51 and 60 years, while that of the females was between 41 and 50 years. The malignancy was found in the rectum in 60.2% of the cases, while the least affected site is the descending colon (1.2%) (NJCP, 2011).