The Effect of Stage, Marital Status and Histology on the Treatment Outcome of Colorectal Cancer in Florida

Colon cancer is the second most prevalent type of cancer in the Westernized world. There has been incongruity on how best to treat colorectal cancer with regard to surgery and/or adjuvant therapies. For early stage colorectal cancer, surgical resection alone can be curative; whereas, the addition of adjuvant therapies have been questioned for stages II and IV. This study seeks to determine the effect of stage, histology and marital status on treatment type (surgery or surgery plus adjuvant therapy) and outcomes. The study resembled a cross-sectional study and used incidence cases of colorectal cancers in Florida from 1994 to 2002. The crude risk ratio was calculated, along with strata-specific ratios. Effect modification was determined by calculating the percent change in risk ratios between the crude and stratum, while Mantel-Haenszel analysis allowed for determination of confounding, both with a 15% change being significant. The Chi-square general association test was used to determine independence of treatment and outcome in relation to the stratum factor. Data homogeneity was assessed using the Breslow-Day test. The RRCrude for surgery alone compared to surgery and adjuvant therapy was calculated to be 1.20 (1.11, 1.30). Stage was determined to be a confounder, not an effect modifier. Histology and marital status were not effect modifiers or confounders, meaning that they are risk factors. Patients receiving surgery alone as opposed to surgery in conjunction with an adjuvant therapy are forty six percent more likely to die. This implies that for stage I and II cancer, surgery alone may be curative, but for more advanced stages, adjuvant therapy in addition to surgery should be the basic standard of care. It also emphasizes the need for regular colonoscopies among populations at risk.