COLORECTAL CANCER

SITE DISTRIBUTION

Abstract

Introduction: Colorectal cancer is a potentially fatal gastrointestinal disease and
has been studied extensively. In an effort to decrease the morbidity and mortality associated
with this disease, studies have been performed to gain insight into the anatomic distribution,
average age at presentation, mean age at presentation for different segments of colon involved
and intersex differences. Objective: The objective of this study is to determine the frequency
of sites of colorectal cancer involvement. Material and methods: Study design: Study was
descriptive case series. Setting: General surgical department post graduate Lady Reading
Hospital Peshawar. Period: From 01/01/2011 to 30/06/2012. Sample size: Sample size was
416 using 3.57% proportion of descending colon5, 95% confidence level and 1.785% margin of
error under WHO software for sample size determination. Sampling technique: Consecutive
non probability sampling. Results: This study was carried out in 416 consecutive patients.
These patients included 233 men (56 %) and 183 women (44%). Age varied from twelve years
to seventy years. The commonest age group in the study at the time of presentation was63-
72 years. Commonest site involved was rectum (26%) followed by sigmoid colon (16%).
Bleeding per rectum was the commonest symptom (62.05%) followed by altered bowel habits
(35.71%). Twelve patients (21.43%) presented with intestinal obstruction. Histopathologically,
twenty patients had well differentiated adeno-carcinoma (35.72%) whereas eighteen patients
had anaplastic tumour (32.14%) and mucinous adeno-carcinoma was found in five patients
(8.92%).Conclusion: Rectum is the most common site of tumour followed by left, right and
transverse colon respectively. The site of involvement affects the surgical procedure required.
In conclusion the symptoms of colorectal cancer may not be representative of any anatomical
site, by the time symptoms appear the lesion may have become invasive.