The relationship between body mass index (BMI) and treatment outcomes has long been under scrutiny, particularly concerning its influence on pathological complete response (pCR) rates among breast cancer patients undergoing neoadjuvant chemotherapy (NAC). A recent study unveils new insights focusing on Brazilian women, where the findings suggest BMI may not play as pivotal a role as previously thought.
Breast cancer is the most common malignancy among women, resulting globally in significant morbidity and mortality each year. Previous research has documented factors such as tumor subtype, treatment regimen, and patient characteristics influencing pCR as well as overall survival (OS). Investigators from Hospital Pérola Byington and Hospital do Servidor Público Estadual examined the interaction between BMI and these pivotal treatment outcomes within the Brazilian population, aiming to fill gaps left by preceding studies.
Conducted as a retrospective cohort study involving 1,751 patients diagnosed with stage I-III invasive primary breast cancer between January 2011 and December 2020, the research evaluated how various BMI categories—normal, overweight, and obese—affect pCR, recurrence-free survival (RFS), and OS. A staggering 35.5% of women included were classified as obese, with most participants being postmenopausal. Notably, the study revealed no significant associations between BMI categories and rates of pCR or survival outcomes.
The findings also pointed out other characteristics of the tumor types predominant in the cohort, noting especially the prevalence of triple-negative and luminal B subtypes. More than three-quarters of patients underwent radical surgery, narrowed down to 79.8%, achieving only a 22.3% pCR rate. Alarmingly, over 30% of the women experienced recurrences, primarily systemic.
Throughout the study, the researchers highlighted contrasting data with international findings noting several studies associatively linking higher BMI with lower pCR rates. Specifically, they pointed out the dynamic of healthcare access as it relates to treatment protocols—another factor distinctively playing out within the lower socioeconomic strata of Brazilian patient care.
Indeed, the results indicated, "BMI was not associated with pCR, RFS, or OS in this large Brazilian cohort, highlighting the need for future studies to explore BMI dynamics during treatment." This statement signifies the importance of underlying factors potentially overshadowed by the sole focus on BMI.
Further exploration is encouraged on how treatment regimens affect outcomes, alongside recommendations for future studies to evaluate possible changes in BMI during therapy, as studies have indicated fluctuations might influence therapeutic efficacy.
The study stresses the necessity of increasing access to advanced therapies, with the Brazilian Unified Health System (UHS) presenting barriers, especially for aggressive breast cancer types, and calls for interventions addressing obesity—a significant public health issue impacting healthcare outcomes beyond cancer mortality.
With the growing challenge of obesity, which has surged among Brazilian women—where over 50% fall within overweight or obese categories—therapeutic strategies need adjustment. It is pivotal to develop comprehensive weight management programs incorporated within oncologic care to mitigate risks associated with obesity-related conditions, as emphasized by the authors.
Conclusively, the research findings question the long-held belief correlatively linking BMI to pCR rates and survival, pivoting the narrative toward broader health management strategies and reinforcing the call for future extensive studies tackling real-world patient interactions with breast cancer therapies. This should involve rigorous examination of treatment outcomes across diverse patient demographics and healthcare environments.
The imperative remains clear: addressing the dual crises of breast cancer treatment and rising obesity rates holds the key to improving outcomes for Brazilian women with breast cancer, as evidenced by the urgent need for optimal public health strategies.