When does curatively treated colorectal cancer recur? An Australian perspective

Abstract

Background: While most colorectal cancer (CRC) recurrences reportedly occur within 3 years following curative treatment, many studies are limited by short-term follow-up. This study examines the time to recurrence of CRC in a large Australian cohort with a long follow-up period and assesses whether time to recurrence has changed over time.Methods: A comprehensive prospective database of patients undergoing resection for CRC is maintained at Concord Hospital, Sydney. Demographic and time to recurrence data were extracted for patients who developed a recurrence following potentially curative resection for colon cancer from 1995 to 2010 and rectal cancer from 1971 to 2010. Non-deceased patients had a minimum of 5 years follow-up. Results: Between 1995 and 2010, 2575 patients with CRC underwent surgery. After exclusions, 386 had recurrence following potentially curative resection, ranging from 1 to 172.5 months (median 20.3) after treatment. Within 1 year, 27.5% recurred, 57.5% by 2 years, 74.6% by 3 years, 85.5% by 4 years and 89.6% by 5 years. There was no difference in time to recurrence between colon and rectal cancers (P = 0.674). Among patients having a potentially curative resection for rectal cancer between 1971 and 2010, 386 recurred. There was no difference in time to recurrence by decade (P = 0.863). Conclusion: The majority of recurrences occurred within 3 years of curative treatment. Had surveillance been limited to 5 years, detection of more than 10% of recurrences would have been delayed. Time to recurrence for rectal cancer has not changed in over 40 years, despite treatment advances.

Identifying Recurrences Among Non-Metastatic Colorectal Cancer Patients Using National Health Data Registries: Validation and Optimization of a Registry-Based Algorithm in a Modern Danish Cohort

“…Between 70% and 90% of the recurrences are detected within the first 3 years after surgery. [2][3][4][5][6][7][8][9] In Denmark and many other countries, CRC recurrence is not recorded routinely in clinical databases or nationwide healthcare registries. Therefore, Lash et al developed and validated an algorithm combining data from different Danish registries to identify CRC recurrences for the period 2001-2011.…”

“…Three years of complete follow-up would be preferable as 90% of all recurrences occur within this timeframe. [2][3][4][5][6][7][8][9]…”

IMPROVE-IT2: implementing noninvasive circulating tumor DNA analysis to optimize the operative and postoperative treatment for patients with colorectal cancer – intervention trial 2. Study protocol

“…At time of diagnosis, 75% of patients present with non-metastatic disease, for which standard of care is curative surgery [1]. Following curative surgery 15-20% of patients experience recurrence of which 70-90% are detected within 3 years of surgery [2][3][4][5][6][7][8][9]. Due to the high recurrence risk, adjuvant chemotherapy is standard of care for high risk UICC stage II and UICC stage III patients [10], but still 33% experience recurrence [4,6,11].…”