Demographics, Pathologic Patterns and Long-term Survival in Operable Colon Cancers: Local Experience in Pakistan

Background: Colon cancer is a common malignancy with its incidence reportedly rising in Asian Countries,including Pakistan. There are no comprehensive data available from Pakistan which focus on associations ofvarious factors with long-term survival of colon cancer. We therefore present an analysis of findings from ourcentre. Methodology: In this retrospective study adult patients with colon cancer diagnosed through 2000-2003were included. A comprehensive questionnaire was filled for each individual through review medical and pathologyreports. Long term survival data was collected from contactable patients or their relatives.
Results:A total of 93patients were assessed, 57 males and 36 females (M: F= 1.58: 1). Mean age of diagnosis was 54 years. Of the total,49.5% of the patients had right sided ( mortality rate 51.6%), 10.8% had transverse colon, (mortality rate37.5%), 7.5% had descending colon (mortality rate 66.7%) and 32.2% had sigmoid colon (mortality rate40.9%) cancers. Stage I disease on diagnosis was found in 16%, stage II in 42.7 (mortality 40 %) and stage IIIin 41.3% ( mortality 70 %). Tumors were well differentiated in 20.2% (mortality 42.9%), moderately differentiatedin 61.9% (mortality 43%) and poorly differentiated in 17.9%( mortality 70%). In 36.3% of the patients lessthan 12 lymph nodes were removed (mortality 55% Vs 43% in patients with > 12 lymph nodes removed). Marginswere free in most patients but a radial margin was reported in only 44%. Most patients had pure adenocarcinomawhile a mucinous type differentiation was seen in 19.7%, 3% had signet ring morphology, 1.5% adeno-squamouscarcinoma and similar number with neuroendocrine differentiation. Overall 5 year all cause mortality for allstages combined was 46.9%.
Conclusion: Colon cancer in Pakistan commonly presents at an advanced stage,there is a male preponderance, and relatively mean younger age at presentation for males is seen. Advancedstage and lymph node involvement along with poorly differentiated pathology, signet ring or mucinousmorphology, location in descending colon, positive surgical margins and removal of less than twelve lymphnodes are factors associated with poor long term survival. There is a need to reinforce information about coloncancer and larger studies from the region are needed to confirm the factors analyzed here.