Published online Jan 27, 2021. doi: 10.4240/wjgs.v13.i1.50
Peer-review started: October 27, 2020
First decision: November 30, 2020
Revised: December 9, 2020
Accepted: December 17, 2020
Article in press: December 17, 2020
Published online: January 27, 2021
Colorectal cancer is a common malignancy with a quite high recurrence rate in spite of the curative treatments utilized. Although most of the recurrences occur within the first three years, a percentage of them appear beyond five years after surgery. Early detection of these recurrences is of paramount importance to allow further curative treatments and improve patient prognosis. However, several different follow-up programs have been proposed over the year, mostly ending in 5 years after surgery.
Prognostic factors for recurrence, patterns of recurrence, and different prognostic factors for early or late recurrence are rarely reported in the literature, especially in cohorts of patients with a long follow-up period. Identifications of these parameters may allow a correct allocation of the patients in specific and tailored follow-up programs to improve patient prognosis and to reduce the costs.
The objectives of this study are the research of prognostic factors for overall recurrence, for early or late recurrence, and the analysis of the potential patterns of recurrence for the most frequent sites of recurrence evaluating patients with a potential minimum follow-up period of 10 years. Clinical, operative, and pathological potential prognostic factors were evaluated and significant results were found for each one of the prospected objectives. These results may help clinicians in predicting patient prognosis and in choosing more cost-effective patient surveillance strategies.
All the consecutive patients curatively treated for colorectal adenocarcinoma from January 2006 to June 2009 were prospectively included in a database that was retrospectively reviewed. A standardized follow-up program was applied to all the patients. Several prognostic factors about the patient, the treatment used, and the pathological response were evaluated. To evaluate the association between possible prognostic factors and disease-free survival and overall survival a Cox model, Kaplan-Meier method, and log-rank test were used. To estimate possible independent prognostic factors for recurrence a multiple Cox model with a backward selection method was used. To assess the association between each possible prognostic factor and timing to recurrence (< 3 years or ≥ 3 years) a simple logistic regression model was used.
Patients with higher levels of preoperative glycemia and carcinoembrionyc antigen, highest anaesthesiologists score score, presenting with occlusion, receiving a complex operation performed with an open technique, after a longer hospital stay, and showing advanced tumors had a higher chance to develop recurrence. At the multivariate analysis, the independent prognostic factors for recurrence were the hospital stay, N stage 2, and M stage 1. Younger ages were significantly associated with an early recurrence onset. Receiving intermediate colectomies or segmental resections, having an N stage 2 or American Joint Committee on Cancer stage 3 tumors was associated with a higher risk of liver recurrence; metastatic disease at diagnosis with local recurrence; receiving neoadjuvant treatments with lung recurrence; bigger tumors and higher lymph node ratio with peritoneal recurrence (marginally significant). However, these results and, in particular, those about the early vs late recurrence and the pattern of recurrence should be verified in larger series.
Several prognostic factors for recurrence and some specific factors for each site of recurrence have been found and should be taken into account to perform a correct allocation of the patient within tailored cost-effective follow-up programs, eventually extended beyond five years after surgery.
Further studies are needed to confirm these results, possibly prospective studies. The use of the learning machine may offer interesting opportunities in this area. Finally, the analysis of the second malignancies developed during the follow-up, which is marginally mentioned in this study, may represent another potential field of research.