The role of Xeloda in metastasic breast cancer

Currently, breast cancer is the primary reason for death due to cancer in Spanish women aged between 35 and 64 years. Nevertheless, despite detecting an increased incidence, it is observed a decrease on mortality rates, in agreement with it is observed in other European countries. This issue is basically due to the development of programs to sift and the use of widespread systemic treatments, both on early and advanced stages of the disease. During the past decade breast cancer has benefited from incorporation of new antitumor drugs to treat this kind of cancer. These new drugs are able to control, in an effective way, the progress of metastatic disease and slow down or eradicate micrometastasis in early stages.

Patients with metastatic disease have been useful in the study of new active agents and their combinations subsequently used in adjuvant regimens. Breast cancer treatment often achieves important objective responses with different durations of treatment, but these durations have an impact on patient survival. The median of survival in this group varies between 18 and 24 months, and the main objective for the treatment of metastatic breast cancer is palliation by means of the control of disease-related symptoms, with an adequate profile of toxicity, which provides an improvement in quality of life.

There are currently several lines of work on the development of breast cancer treatments at different stages. These are expected to improve survival and quality of life parameters. These lines of development range from the incorporation of new active agents (cytotoxic and hormonal) to optimization of current schemes with active agents (old and new), by means of new combinations used for metastatic disease and use in early stages, even before surgery.

Breast cancer is one of the most chemo sensible solid tumours, that respond to almost every cytotoxic drug used alone or in combination. These active agents include alkylating drugs (e.g. cyclophosphamide and the cisplatins) and antimetabolites (e.g. fluorouracil and methotrexate), which were used for the design of the first-line polychemotherapy schemes in solid tumours such as CMF. After this, the anthracyclines (doxorubicin and epirubicin) were substituted for methotrexate in the latter combination, giving us the FAC and FEC schemes, which were classic treatments until relatively recently. During the past decade, many new agents have been incorporated that have improved both response rates and patient survival, such as the taxanes (paclitaxel and docetaxel), vinorelbine, caelyx and, recently, gemcitabine; there have been used in new combinations or have even been used as isolated agents as second- and third-line treatments for with advanced disease.

The main problem with these agents and their combinations is the complexity of administration, at day hospitals and through intravenous injections, which seriously impairs patient quality of life. However, the benefit in terms of survival parameters and symptom reduction offset these difficulties.

Capecitabine (Xeloda), one of the most recently introduced active agents into treatment for metastatic breast cancer, has the same antitumoral activity as current agents but without many of their inconveniences, which is the reason why its incorporation into standard treatment for breast cancer patients is becoming increasingly common. It is orally administered, avoiding the difficulties associated with intravenous injection. Its mode of action is similar to that of 5-fluorouracyl in continuous infusion, without the need for infuser or central catheters. On the other hand, it has a synergistic action with the majority of cytotoxic drugs, in particular with docetaxel, leading to a better survival rates. The results of studies conducted in recent years have confirmed the important role of capecitabine in the treatment of advanced disease, and it have been the base for the studies with capecitabine on the adjuvant and neoadjuvant setting.