Past studies have identified surgeon- and institution- related characteristics as prognostic factors in colorectal cancer surgery.
Dr Pietro Renzulli and colleagues from Germany assessed the influence of caseload on long-term results of colorectal cancer surgery.
The research team searched data on 2706 patients from 2 randomized, colorectal cancer trials investigating adjuvant intraportal and systemic chemotherapy.
The team also reviewed 1 concurrent registration study.
A first analysis included 1809 eligible, nonmetastatic patients from all 3 studies.
The team conducted a subsequent subgroup analysis and included 915 eligible patients from both randomized trials.
Overall survival, disease-free survival, and local recurrence were analyzed in multivariate models taking into account the possible effect of clustering.
The main potential covariates were surgeon's annual caseload, hospital's annual caseload, tumor site, T stage, and nodal status.
The training status of the surgeon was not a prognostic factor of outcome|
The research team's primary analysis of all 3 studies combined found a high surgeon's caseload to be positively associated with overall survival.
The team noted that the surgeon's caseload was only marginally associated with disease-free survival.
Separate analysis for each trial, however, showed that a high surgeon's caseload was beneficial for outcome in both randomized trials but not in the registration study.
A subgroup analysis of 915 patients with 376 rectal and 539 colonic primaries from both randomized trials, therefore, was performed.
The team found that neither age, gender, year of operation, adjuvant chemotherapy, or hospital academic status predicted outcome.
Neither training status of the surgeon, nor inclusion in 1 of the 2 randomized trials was a significant predictor of outcome.
However, the researchers observed that both high surgeon's and high hospital's annual caseloads were independent prognostic factors.
High surgeon and high hospital annual caseloads were prognostic factors for overall-, and disease-free survival, and marginally significant for local recurrence.
Dr Renzulli's team commented, “High surgeon's and hospital's annual caseloads are strong independent prognostic factors for extending overall and disease-free survival, and reducing the rate of local recurrence in 2 randomized colorectal cancer trials.”