IMPACT OF DELAYED ADJUVANT RADIOTHERAPY ON BREAST CANCER
Authors: Meyer Bianca dos Santos , Oliveira Lélisa Pereira , Franca Carlos Antônio da Silva , Martins Júnior Reynaldo Real , Penna Antônio Belmiro Rodrigues Campbell 
Published: February 2023

Introduction: In documents from the Brazilian Society of Radiotherapy, quantitative analysis revealed that radiotherapy sessions, when performed, have not been timely. The average waiting time between the diagnosis data and the start of radiotherapy has been, on average, 113.4 days — which can consistently affect the chances of being cured for many patients. In some regions, waiting time is even longer; not infrequently, patients are treated with outdated methods and unprecision machines. Radiotherapy in Brazil is in a critical situation, especially with regard to the care of patients assisted by the Brazilian Public Health System (SUS). The main problems that contribute to this scenario are related to inadequate description and poor installation capacity, both from the point of view of the number of devices and their geographic distribution. Objective: The aim of this study was to determine whether delaying the initiation of adjuvant radiotherapy is related to decreased survival in women with breast cancer. Methods: This is a retrospective, descriptive, and longitudinal study (cross section) of patients admitted to the CRI/IBO, Niterói, RJ, all from SUS. Through the review of medical records, 81 patients were selected. Only patients diagnosed with stage IIb (T3N0) breast malignancy according to the American Joint Committee on Cancer TNM 8th (AJCC) were included. The analysis was performed by the time taken to start the radiotherapy after the initial treatment, which was treated by conservative surgery followed by adjuvant chemotherapy. The cohort was divided into two groups according to the timing of radiotherapy after the initial treatment: 6 months. Results: In the data analysis, it was observed that 70 (86.4%) patients did not have disease recurrence, while 11 (13.6%) patients had tumor recurrence. The average time between the end of the last chemotherapy day and the start of adjuvant radiotherapy was 6.1 months (1–12/95%CI 5.5–6.8, SD±2.9). Referring patients to those who provide adjuvant radiotherapy at 6 months (group B), we have 36 patients (44.4%) in group A and 45 patients (55.6%) in group B. In group A (36 patients), 34 patients (94.4%) did not have tumor recurrence and 2 (5.6%) did have tumor recurrence. In group B (45 patients), 36 (80%) patients did not have tumor recurrence and 9 (20%) did have tumor recurrence, with p=0.0001. Bearing in mind that the objective of the study is disease-free survival in 5 years, the mean follow-up time of patients was 69.8 months (51–92/95%CI 68.2–71.3, SD±7.0). It was evaluated that patients who had adjuvant radiotherapy in less than 6 months had a longer survival than patients who had more than 6 months (p <0.001). Therefore, patients with a delay of more than 6 months in the initial adjuvant radiotherapy treatment had an impact on the 5-year disease-free survival. Conclusion: This study is not conclusive, but we were able to observe data that show a worsening in the patient’s survival and prognosis in relation to the delay in the radiotherapy treatment. However, the waiting time for radiotherapy should be as short as reasonably possible, as there is a possibility that this delay will cause worse disease control rates.