Factors associated with disease progression

This study explored factors that could predict disease progression following chemotherapy in breast cancer patients. The authors found that while survival rates were excellent following treatment, patients with faster-growing tumors and those with the luminal B/HER negative or triple negative subtypes had a higher risk of disease progression.

Thanks to a high rate of breast cancer screening, more patients are being identified and treated early in the course of the disease. Chemotherapy following surgery is known to improve survival in breast cancer patients. The use of anthracycline (a form of chemotherapy, such as epirubicin) based chemotherapies is thought to improve disease-free survival (time from diagnosis to relapse) and overall survival. Taxanes (another type of chemotherapy, such as paclitaxel) can also be combined with other chemotherapies to improve survival. However, these therapies can be very toxic, and cause many negative side effects. Therefore, these combinations are usually reserved for patients with poor prognosis or a high risk of cancer recurrence. It would be beneficial to know which patients with early breast cancer would benefit most from this treatment combination.

This study examined the records of 757 early breast cancer patients treated with anthracycline-based chemotherapy. Patients were followed for an average of 70 months.

The overall 5-year survival rate among treated patients was 95.1%. The 5-year disease-free survival rate was 90.6%. The 5-year distant disease-free rate (time from diagnosis until metastatic recurrence) was 92.8%.

Patients with grade 3 tumors (tumors with faster growing cells according to appearance under a microscope) were 2.8 times more likely to see disease progression. Patients with luminal B/HER2 negative (tumors dependent on the hormones estrogen or progesterone for growth but not on HER2) were 4.25 times more likely to progress compared to other subtypes. Patients with triple negative (not dependent on hormones or HER2 for growth) were 2.5 times more likely to progress. These subtypes, and patients with grade 3 tumors, were also more likely to experience metastatic recurrence.

This study concluded that early breast cancer patients with grade 3 tumors or certain subtypes (luminal B/HER2 negative or triple negative) were more likely to see disease progression following chemotherapy. The authors suggested that these patients may benefit from more aggressive treatment.