Hormone therapy/adjuvant chemotherapy induced deleterious effects on the bone mass of breast cancer patients and the intervention of physiotherapy: a literature review

In recent years, breast cancer has witnessed some notable improvements regarding early diagnosis and new therapeutical strategies, mainly because of the utilization of new drugs and systemic treatment protocols, which have had a direct impact in the increase of these patients' global survival rate. At the same time, it is an ever-growing concern among oncology professionals to identify and minimize as much as possible the effects of long-term toxicity resulting from cancer therapies. Within this context, physiotherapy fits as a preventive and rehabilitating factor regarding functional and skeletal alterations, deriving not only from the direct action of breast cancer, but also from the treatment to which these patients are submitted. Objectives: The aim of this study was to revise the scientific literature on possible adjuvant chemotherapy-induced secondary deleterious effects on the bone mass of patients diagnosed with breast cancer, and also to revise the literature on the intervention of physiotherapy in cases of secondary bone mass loss caused by adjuvant chemotherapy in patients suffering from breast cancer. Methodology: The research was carried out by consulting the following medical websites: Medicus Medline Index, Lilacs, Sciello, PubMed (National Library of Medicine), Google Academic and Capes (a Brazilian website for scientific information). The selection gathers articles written in different languages, English in special, published from January 1998 to October 2008. Results: 24 studies explicitly mention chemotherapy-induced direct and/or indirect effects upon bone mass. Different authors refer to bone mass loss as one possible secondary deleterious effect resulting from adjuvant chemotherapy applied in breast cancer treatment. Nonetheless, no scientific articles were found on the subject of physiotherapy intervention aimed at patients in this specific condition. Conclusion: the results achieved in this revision study point out the possible chemotherapy-induced late deleterious effects on patients diagnosed with breast cancer, as well as the additional risks for the development of further osteoporotic conditions. Hormone therapy and adjuvant chemotherapy treatments may in fact augment and accelerate the loss of bone mass, be it directly, through the action of chemotherapeutical drugs, or indirectly, through the reduction of estrogenic levels and precocious menopause. The scarce material on the rehabilitation of bone mass loss deriving from adjuvant treatments reveals, as it seems, a strong need for new studies on the subject.