Factors influencing recurrence of stage I-III rectal cancer in regional Australia

Background: As treatments for rectal cancer improve with developments in surgical techniques, radiotherapy and chemotherapy, the nature of recurrences are evolving. We used a comprehensive database of a large Australian population with stage I-III rectal adenocarcinoma to identify timing and prognostic significance of recurrences, and factors associated with risk of developing recurrent disease.

Methods: All patients with locoregional rectal cancer treated with curative intent in our health district from 2006 to 2017 were included. Multivariate analysis using Cox regression models were used to identify factors associated with recurrence.

Results: A total of 483 patients were included. Recurrence occurred in 117 (24.2%) of 483 patients, being locoregional in 15 (3.1%) patients, distant in 85 patients (17.6%) and both locoregional and distant in 17 (3.5%) patients. Compared to those with locoregional recurrence, those with both locoregional and distant recurrence had worse cancer-specific survival. On univariate analysis, factors associated with recurrence included stage, grade, radiotherapy, chemotherapy, surgery type and distal tumour location. Factors which remained significant on multivariate analysis included higher grade and stage.

Conclusion: In the era of multimodality therapy for rectal cancer, recurrences are predominantly distant. Traditional predictors including higher stage, grade and distal tumour location remain independently associated with recurrence, despite current treatment paradigms.