Published in:
01-11-2013 | Colorectal Cancer
Relative Survival is an Adequate Estimate of Cancer-Specific Survival: Baseline Mortality-Adjusted 10-Year Survival of 771 Rectal Cancer Patients
Published in: Annals of Surgical Oncology | Issue 12/2013
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Background
The objective of the present investigation is to assess the baseline mortality-adjusted 10-year survival of rectal cancer patients.
Methods
Ten-year survival was analyzed in 771 consecutive American Joint Committee on Cancer (AJCC) stage I–IV rectal cancer patients undergoing open resection between 1991 and 2008 using risk-adjusted Cox proportional hazard regression models adjusting for population-based baseline mortality.
Results
The median follow-up of patients alive was 8.8 years. The 10-year relative, overall, and cancer-specific survival were 66.5 % [95 % confidence interval (CI) 61.3–72.1], 48.7 % (95 % CI 44.9–52.8), and 66.4 % (95 % CI 62.5–70.5), respectively. In the entire patient sample (stage I–IV) 47.3 % and in patients with stage I–III 33.6 % of all deaths were related to rectal cancer during the 10-year period. For patients with AJCC stage I rectal cancer, the 10-year overall survival was 96 % and did not significantly differ from an average population after matching for gender, age, and calendar year (p = 0.151). For the more advanced tumor stages, however, survival was significantly impaired (p < 0.001).
Conclusions
Retrospective investigations of survival after rectal cancer resection should adjust for baseline mortality because a large fraction of deaths is not cancer related. Stage I rectal cancer patients, compared to patients with more advanced disease stages, have a relative survival close to 100 % and can thus be considered cured. Using this relative-survival approach, the real public health burden caused by rectal cancer can reliably be analyzed and reported.