The prognostic impact of the time interval to recurrence for the mortality in recurrent colorectal cancer.

OBJECTIVE: The risk of a cancer recurrence has been correlated with the stage of the primary tumour at the time of presentation. However, once a recurrence has developed, the primary tumour stage may not be the determining prognostic factor anymore. The objective of this study was (i) to evaluate the association between the recurrence interval and the outcome of the recurrence, and (ii) to determine whether that interval was affected by the use of adjuvant radiation and/or chemotherapy.
METHOD: This retrospective study analysed 212 patients who developed recurrent colorectal cancer from 1987 to 1993. Primary parameters such as age, gender, primary tumour site and stage, and use of postoperative adjuvant treatment were correlated with the recurrence interval, the type and site of the recurrence (i.e. locoregional vs distant metastases), and the outcome. Uni- and multivariate analysis was used to compare the recurrence interval and survival between different subgroups as defined by risk factors.
RESULTS: The mean time between the primary and the recurrent tumour was 25 months (range 1-252 months) with 82% of the recurrences developing within 3 years after surgery. The recurrence interval was inversely correlated with the initial tumour stage. Poor survival was associated with a short recurrence interval (less than 12 months) and a distant recurrence site. Even after adjusting for the initial tumour stage, the use of adjuvant treatment did not prolong the interval, i.e. delay the onset of recurrent cancer.
CONCLUSION: The recurrence interval of colorectal cancer is a prognostic factor. However, the use of adjuvant therapy did not prolong that interval.