Treatment Outcome of Neoadjuvant Therapy for Locally Advanced Rectal Cancer a Single Institution Experience

Abstract

Background: Rectal cancer is daunting disease that has been significantly associated with high rate of recurrence and metastasis. According to Globocan report in 2020, rectal cancer is among the top ten cancers in Kenya with an incidence of 2.3% and 2.5% mortality rate. Locally advanced rectal cancer (LARC) involve tumours that extend to the mesorectal fascia. Thus, in management of this condition, a complete removal of the tumour and mesorectum is essential on local control and survival. The use of neoadjuvant therapy has been observed as essential in management of LARC resulting in improved overall survival, progression free survival, and local control. However, the outcomes of neoadjuvant therapy in management of LARC have not been fully investigated in the Kenyan setting. Broad Objective: To establish the outcomes of neoadjuvant therapy in LARC a single institution study at the Cancer Treatment Centre, Kenyatta National hospital between January 2016 and January 2020. Methodology: The study adopted a retrospective study design. A complete enumeration was be done where all 182 patient files were targeted between January 2016 and January 2020. The inclusion criteria comprised patients treated for locally advanced rectal cancer diagnosed in Kenyatta National Hospital, patients who completed neoadjuvant therapy, and a histological subtype of adenocarcinoma. A structured data abstraction tool was developed to help in data extraction from patients with LARC. The data that was extracted from the files. Results: The average age of 54.2 years, more than half of the patients, 52.5% were female. More than half of the patients, 57.5% were at T3 at diagnosis. Progression free survival and overall survival were investigated. The median progression free survival after neoadjuvant treatment was 24 (IQR: 23 – 25) months. The overall survival median was 36 (IQR: 24 – 36) months. The bivariate analysis revealed that presence of comorbidities (β = - 4.2, p =0.041), tumor staging (β = - 4.4, p =0.003), Duration of symptoms before diagnosis (β = - 0.07, p =0.028), and treatment modality (β = - 7.2, p =0.026), were predictors of overall survival. Multiple regression analysis revealed that presence of comorbidities (β = - 4.6, p =0.023), tumor staging (β = - 6, p =0.009) and duration of symptom before diagnosis (β = - 0.1, p =0.039) were independent predictors of overall survival. Conclusion and recommendations: The findings have showed that presence of comorbidities, tumor staging at diagnosis and the longer duration of symptoms before diagnosis were independent predictors of poor overall survival. Thus, there is need to ensure regular screening for rectal cancer should be done across all ages to control late diagnosis of the disease at advanced stage