A study of breast cancer in Italian women has found that more than 70% of those affected by the disease are over the age of 50 years, and the disease is identified before it has spread to the lymph nodes in more than 60% of cases.
Dr Matteo Clavarezza reported the findings of a retrospective study sponsored by Sanofi-Aventis at the 35th Congress of the European Society for Medical Oncology (ESMO) in Milan, Italy.
Dr Clavarezza and colleagues at hospitals and institutes across the country studied more than 1500 cases of breast cancer between January 1 and July 30, 2008. The centers involved in the study were chosen to reflect the demographic situation in Italy (from database of oncologic centers in the "Libro bianco" of the Italian Society of Medical Oncology, AIOM).
"The first important observation is the demographics of breast cancer," Dr Clavarezza said. "The breast cancer population in Italy is today composed mostly of elderly patients. In fact, 21.7% of the study population were women aged 70 years or over, 73.6% were at least 50 years old and 69% were postmenopausal."
The researchers found that 22.3% of breast cancers were identified before they were larger than 1 centimeter in diameter, and 61% were node-negative, meaning the cancer had not spread to the lymphatic system.
Only 9.9% of tumors were classified as high risk, meaning that four or more lymph nodes were found to be harboring cancer cells. "This fact underlines the very early diagnosis of breast cancer in Italy," Dr Clavarezza said.
The researchers also found that the breast cancer cases in their study were less likely than expected to express the HER-2 gene.
While HER2 positive breast cancer is generally recognized to account for 20-25% of all breast cancer, in this study only 16.1% of tumors were HER2-positive. Also, hormonal receptors were positive in 83.5% of this study population, compared to the expected approximately 75%.
"So, probably influenced by the high number of elderly patients and the high proportion of postmenopausal women, the biology of breast cancer in Italy today tends to be hormone-receptor positive and HER2 negative --the so-called classical endocrine-responsive disease," Dr Clavarezza said.
In terms of the treatment offered to Italian breast cancer patients, the study focused on which patients receive adjuvant chemotherapy --meaning chemotherapy in addition to surgery to remove the tumor.
"We found that the most important parameters influencing the choice of adjuvant chemotherapy are the patient's age, the stage of their disease, and whether the tumor expressed hormonal receptors and HER2," Dr Clavarezza said.
Aside from the biology of the tumor the most important parameter that affected whether a patient received adjuvant chemotherapy was the stage of the tumor. Patients with larger tumors were more likely to receive chemotherapy, as were those whose lymph nodes were positive.
"Italian oncologists are today greatly influenced by prognostic factors, rather than predictive biological parameters, when choosing adjuvant chemotherapy," he said.
In terms of the type of chemotherapy, 9.1% of patients received a 'CMF-like' regimen, 48.8% were given anthracycline-containing chemotherapy, 38.4% received anthracyclines and taxanes, and 3.7% were administered taxanes alone.
The researchers were surprised to find that the choice of what type of chemotherapy a patient received was mostly influenced by the stage of the patient's disease --how large the tumor was and whether it had spread to the lymph nodes.
"The most effective regimens were used more often with increasing stage," Dr Clavarezza said. "Biological parameters did not influence type of chemotherapy: only patients with HER2 positive tumors were a little more likely to receive anthracycline and taxanes together compared to HER2-negative patients."
"So, Italian oncologists are influenced in the choice of the type of chemotherapy they use by prognostic parameters. The higher the risk of recurrence, the more likely they are to use the most effective regimens. This is a critical choice and I think not always correct: if a patient is a candidate for adjuvant chemotherapy, they should receive the most effective treatment."
"It is clear that in Italy, breast cancer is increasingly being detected earlier and with more favorable characteristics than in the past," commented Dr Roberto Labianca from Ospedali Riuniti di Bergamo, Italy. "This emphasizes the role of screening and early diagnosis."
But when prescribing adjuvant treatment, Italian oncologists seem to be much more influenced by prognostic factors than by biological factors that might predict response to therapy, he added.
"This means not only that patients with more advanced disease tend to be given more effective and 'aggressive' chemotherapy, but also that there is probably an over-prescription of chemotherapy in comparison to endocrine therapy alone."
Journal
Annals of Oncology