Moderately hypofractionated post-operative radiation therapy for breast cancer: preferences amongst radiation oncologists from countries in Latin America and the Caribbean.

Background: The safety and effectiveness of moderately hypofractionated post-operative radiation therapy for breast cancer were demonstrated by several trials. This study aimed to evaluate the current patterns of practice and prescription preference about moderately hypofractionated post-operative radiation therapy to assess possible aspects that affect the decision-making process regarding the use of fractionation in breast cancer patients in Latin America and the Caribbean (LAC). We also aimed to identify factors that can restrain the utilization of moderately hypofractionated post-operative radiation therapy for breast cancer. Materials an methods: Radiation oncologists from LAC were invited to contribute to this study. A 38-question survey was used to evaluate their opinions. Results: A total of 173 radiation oncologists from 13 countries answered the questionnaire. The majority of respondents (84.9%) preferred moderately hypofractionated post-operative radiation therapy as their first choice in cases of whole breast irradiation. Whole breast plus regional nodal irradiation, post-mastectomy (chest wall and regional nodal irradiation) without reconstruction, and post-mastectomy (chest wall and regional node irradiation) with reconstruction hypofractionated post-operative radiation therapy was preferred by 72.2% 71.1%, and 53.7% of respondents, respectively. Breast cancer stage, and flap-based breast reconstruction were the factors associated with absolute contraindications for the use of hypofractionated schedules. Conclusion: Even though moderately hypofractionated post-operative radiation therapy for breast cancer is considered a new standard to the vast majority of the patients, its unrestricted application in clinical practice across LAC still faces reluctance.

Safety of CDK4/6 Inhibitors Combined with Radiotherapy in Patients with Metastatic Breast Cancer: A Review of the Literature.

Recent evidence suggests that cyclin-dependent kinase 4/6 (CDK4/6) inhibitors significantly improve progression-free survival and overall survival among metastatic breast cancer patients. However, given the effects on cell cycle arrest, there is potential for CDK4/6 inhibitors and radiotherapy (RT) to work synergistically, enhancing the effect and toxicities of RT. A comprehensive review of the literature on the combination of RT and CDK4/6 inhibitors was performed with 19 eligible studies included in the final analysis. A total of 373 patients who received radiotherapy combined with CDK4/6 inhibitors were evaluated across 9 retrospective studies, 4 case reports, 3 case series, and 3 letters to the editor. The CDK4/6 inhibitor used, RT target, and RT technique were assessed in terms of toxicities. This literature review demonstrates generally limited toxicities with the combination of CDK4/6 inhibitors and palliative radiotherapy to metastatic breast cancer patients. The current evidence is nonetheless limited, and further results of ongoing prospective clinical trials will help clarify whether these treatments can be safely combined.

Partial Breast Irradiation.

Breast cancer is the most common cancer in women worldwide. Over the past few decades, remarkable progress has been made in understanding the biology and pathology of breast cancer. A personalized conservative approach has been currently adopted addressing the patient's individual risk of relapse. After postoperative whole breast irradiation for early-stage breast cancer, a rate of recurrences outside the initial tumour bed lower than 4% was observed. Thus, the highest benefits of breast irradiation seem to result from the dose delivered to the tissue neighbouring the tumour bed. Nonetheless, reducing treatment morbidity while maintaining radiation therapy's ability to decrease local recurrences is an important challenge in treating patients with radiation therapy. In this regard, strategies such as partial-breast irradiation have been developed to reduce toxicity without compromising oncologic outcomes. According to the national and international published guidelines, clinical oncologists can refer to specific dose/fractionation schedules and eligible criteria. However, there are still some areas of open questions. Breast cancer represents a multidisciplinary paradigm; it should be considered a heterogeneous disease where a "one-treatment-fits-all" approach cannot be considered an appropriate option. This is a wide overview on the main partial breast irradiation advantages, risks, timings, techniques, and available recommendations. We aim to provide practical findings to support clinical decision-making, exploring future perspectives, towards a balance for optimisation of breast cancer.

A Prospective Cohort Study of Biomarkers in Squamous Cell Carcinoma of the Anal Canal (SCCAC) and their Influence on Treatment Outcomes.

Background: Although Chemoradiation (CRT) is the curative treatment for SCCAC, many patients present primary resistance. Since it is a rare tumor, response predictors remain unknown. Methods: We performed a prospective cohort study to evaluate biomarkers associated with CRT response, progression-free survival (PFS), and overall survival (OS). The primary endpoint was response at 6 months (m). Tumor DNA and HPV were analyzed by next-generation sequencing, while KI-67 and PD-L1 by immunohistochemistry in tumor tissue. Results: Seventy-eight patients were recruited between October/2011 and December/2015, and 75 were response evaluable. The median age was 57 years, 65% (n=49) were stage III and 12% (n=9) were HIV positive (HIV+). At 6m, 62.7% (n=47) presented CR. On multivariate analyses, stage II patients were 4.7 more likely to achieve response than stage III (OR, 4.70; 95%CI, 1.36-16.30; p=0.015). HIV+ was associated with a worse response (OR, 5.72; 95%CI, 2.5-13.0; p<0.001). 5-year PFS and OS rates were 63.3% and 76.4%, respectively, with a median follow up of 66m. On multivariate analyses, older age (HR 1.06, p=0.022, 95%IC 1.01-1.11) and absence of CR at 6m (HR 3.36, p=0.007, 95%IC 1.39-8.09) were associated with inferior OS. The 5-year OS rate was 62.5% in HIV+ group compared to 78% among HIV- pts, although this difference was not statistically significant (p=0.4). PIK3CA, MET and TP53 mutations, HPV, Ki-67 expression, and PD-L1 expression, were not associated with PFS and OS. Conclusions: Clinical stage III and HIV+ were associated with worse response to CRT at 6m. The absence of CR was the main factor associated with poor 5-year OS.

Timing factors as prognostic variables in patients with head and neck squamous cell carcinoma treated with adjuvant radiotherapy: a literature review.

INTRODUCTION: Radiotherapy (RT) plays an important role in the treatment of patients with head and neck neoplasia, and is frequently used as postoperative adjuvant therapy. This study aimed to review the literature about timing factors that may influence the clinical outcomes of patients with advanced head and neck neoplasia treated with adjuvant RT. RESULTS: Timing factors such as total treatment time, length of adjuvant RT, and the absence of interruptions during RT may influence the clinical outcome of these patients. CONCLUSIONS: In the same way that certain tumor factors can affect the prognosis of patients with squamous cell carcinoma of the head and neck, some therapeutic timing factors are also prognostic factors and therefore, must be carefully orchestrated in order to avoid loss at therapeutic outcomes for these patients.

Influence of time between surgery and postoperative radiation therapy and total treatment time in locoregional control of patients with head and neck cancer: a single center experience.

OBJECTIVE: This study aimed to evaluate the effect of the delay to initiate postoperative radiation therapy (RT) on locoregional control to head and neck squamous cell carcinoma patients. METHODS: Retrospective cohort study that included patients submitted to surgery followed by adjuvant RT (with/without chemotherapy). The time interval between surgery and RT was dichotomized by the receiver operating characteristics curve method at 92 days. Other possible sources of heterogeneity with potential impact on locoregional control were explored by regressive analysis. RESULTS: A total of 168 patients were evaluated. The median time for locoregional recurrence (LRR) was 29.7 months. The relapse-free survival rates were 66.4% and 75.4% for patients who initiated RT more than and within 92 postoperative days (p=0.377), respectively. Doses lower than 60Gy were associated with worse rates of locoregional control (HR=6.523; 95%CI:2.266-18.777, p=0.001). Patients whose total treatment time (TTT) was longer than 150 days had LRR rate of 41.8%; no patient with TTT inferior to 150 days had relapses (p=0.001). CONCLUSIONS: The interval between surgery and RT did not show influence on locoregional control rates. However, doses <60Gy and the total treatment time >150 days were associated with lower locoregional control rates.

Timing factors as prognostic variables in patients with head and neck squamous cell carcinoma treated with adjuvant radiotherapy: a literature review

SUMMARY INTRODUCTION Radiotherapy (RT) plays an important role in the treatment of patients with head and neck neoplasia, and is frequently used as postoperative adjuvant therapy. This study aimed to review the literature about timing factors that may influence the clinical outcomes of patients with advanced head and neck neoplasia treated with adjuvant RT. RESULTS Timing factors such as total treatment time, length of adjuvant RT, and the absence of interruptions during RT may influence the clinical outcome of these patients. CONCLUSIONS In the same way that certain tumor factors can affect the prognosis of patients with squamous cell carcinoma of the head and neck, some therapeutic timing factors are also prognostic factors and therefore, must be carefully orchestrated in order to avoid loss at therapeutic outcomes for these patients.

RESUMO INTRODUÇÃO A radioterapia (RT) tem importante papel no tratamento dos pacientes com neoplasia de cabeça e pescoço, sendo frequentemente utilizada como terapia adjuvante a fim de diminuir a probabilidade de recorrência local. O presente estudo tem o objetivo de realizar uma revisão da literatura para avaliar os fatores terapêuticos temporais que possam ter influência sobre os desfechos clínicos dos pacientes com neoplasia avançada de cabeça e pescoço tratados com RT adjuvante. RESULTADOS As variáveis terapêuticas, como o tempo total do tratamento, a duração da RT e a ausência de interrupções durante o tratamento radioterápico são capazes de impactar o resultado clínico dos pacientes. CONCLUSÕES Da mesma forma que determinados fatores tumorais podem afetar o prognóstico de pacientes com carcinoma de células escamosas de cabeça e pescoço, alguns fatores terapêuticos temporais também constituem fatores prognósticos e, portanto, devem ser rigorosamente orquestrados a fim de se evitarem prejuízos sobrepostos para esses pacientes.

Influence of time between surgery and postoperative radiation therapy and total treatment time in locoregional control of patients with head and neck cancer: a single center experience

OBJECTIVE: This study aimed to evaluate the effect of the delay to initiate postoperative radiation therapy (RT) on locoregional control to head and neck squamous cell carcinoma patients. METHODS: Retrospective cohort study that included patients submitted to surgery followed by adjuvant RT (with/without chemotherapy). The time interval between surgery and RT was dichotomized by the receiver operating characteristics curve method at 92 days. Other possible sources of heterogeneity with potential impact on locoregional control were explored by regressive analysis. RESULTS: A total of 168 patients were evaluated. The median time for locoregional recurrence (LRR) was 29.7 months. The relapse-free survival rates were 66.4% and 75.4% for patients who initiated RT more than and within 92 postoperative days (p=0.377), respectively. Doses lower than 60Gy were associated with worse rates of locoregional control (HR=6.523; 95%CI:2.266-18.777, p=0.001). Patients whose total treatment time (TTT) was longer than 150 days had LRR rate of 41.8%; no patient with TTT inferior to 150 days had relapses (p=0.001). CONCLUSIONS: The interval between surgery and RT did not show influence on locoregional control rates. However, doses <60Gy and the total treatment time >150 days were associated with lower locoregional control rates.