Difference in Outcome Between Surgery and Radiotherapy for Localized and Regional Prostate Cancer

There are no established guidelines for the management of low-risk, localized prostate cancer. In this analysis we assess the efficacy of two treatments, radiotherapy and radical prostatectomy, for improved outcomes in subsequent cancer recurrence stratified by cancer stage and histology. Treatment response is dependent upon tumor grading and lymph node involvement. Histology and stage are key prognostic factors used in the decision-making process for treatment of prostate cancer. This is a secondary data analysis of 53437 prostate cancer incidences cases from the Florida Cancer Registry. JMP is used to calculate RR of cancer evidence (outcome) by treatment option (exposure). Mantel-Haenszel stratified analysis assesses the effect of treatment on evidence stratified by four cancer histologies (adenocarcinoma, carcinoma, acinarcarcinoma, malignant) and two clinical stages (localized, regional). A two-level stratified analysis of crossed effect determines significant stratum-specific RR associations. It was found that evidence of cancer is 2.2 times more likely with radiation therapy versus surgery (Table 1). Outcome was shown to be associated to stage (p < 0.0001) and histology (p < 0.0001) (Table 2 and Table 3). Mantel-Haenszel RR and CI for stage and histology show significant adjusted association to outcome and identify them as effect modifiers with 50% and 33% changes respectively from RR crude across strata (Table 3). Interpretation of crude RR suggests radiotherapy is less reliable than surgery for treating most prostate cancers. Specifically, risk difference data suggests that localized adenocarcinomas 54 (RR=2.80) are 39% more likely than regional adenocarcinomas (RR = 1.41) to have recurrence with radiotherapy than with surgery alone.