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Estimating the cure proportion of colorectal cancer and related factors after surgery in patients: using parametric cure models

Neda Izadi, Fatemeh Koohi, Mahdi Safarpour, Parisa Naseri, Salar Rahimi, Soheila Khodakarim



Aim: This study aimed to estimating the cure proportion and effects of related factors on colorectal cancer in Iranian patients after surgery.

Background: Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the fourth leading cause of cancer death. The relative survival of CRC varies around the world due to the quality of care, including surgical techniques

Methods: The 490 adults aged 20–94 years diagnosed with colorectal cancer who were surgeries in Shiraz Faghihi Hospital-Iran, were eligible for analysis. We used parametric cure model (mixture and non-mixture) to estimate the cure proportion and the adjusted hazard ration (OR) for colorectal cancer mortality after surgery. Data were analyzed by the “flexsurvcure” package in R software (version 3.4.2).

Results: The median age of patients was 57.5 (IQR=18) years. 56.33% of the patients were male. The median time of follow up in patients was 618 days. The cumulative survival proportion varied from 0.90 to 0.49 and indicates a decrease and then a flat line in the probability of survival by sex. The flexible survival for adjusted cure proportion (%) was 69.3 and 68.3 in the mixture and non-mixture cure models, respectively. Only obesity was associated with a decreased risk of mortality (OR=0.34; 95% CI: 0.12-0.97).

Conclusion: The overall eight-year survival proportion for CRC was 49%. By having the cure proportion and its related factors in patients with CRC, better service can be provided. Therefore the early detection and screening strategies are needed to reduce mortality and increase survival of patients.


Cure Proportion, Related Factors, Colorectal Cancer, Parametric Cure Model

DOI: https://doi.org/10.22037/ghfbb.v13i2.1807