Consumer Safety Watch Warns Paclitaxel Weekly More Effective, Has Fewer Side Effects Than Docetaxel for Women Diagnosed With Breast Cancer That Had Spread to the Lymph Nodes

A recent study concluded that treatment with paclitaxel weekly had more benefits than treatment with paclitaxel every three weeks for women diagnosed with breast cancer that had spread to the lymph nodes or women diagnosed with breast cancer that hadn't spread to the lymph nodes but was considered high risk. Getting paclitaxel every week also had more benefits than getting docetaxel weekly or every three weeks for these women without the risk of permanent or persistent hair loss or thinning or spotting hair.

In this study of 5,000 women, more women who received paclitaxel once a week were likely to be alive and free of breast cancer five years after being diagnosed compared to women who received paclitaxel every three weeks or women who received docetaxel (either weekly or every three weeks). All the women received doxorubicin and cyclophosphamide before receiving either paclitaxel or docetaxel.

For women diagnosed with early-stage, lymph-node-positive breast cancer, treatment often includes chemotherapy with doxorubicin and cyclophosphamide followed by a taxane. This chemotherapy regimen is sometimes called AC followed by T. paclitaxel, docetaxel, and albumin-bound or nab-paclitaxel are all taxanes. In the AC followed by T regimen, a taxane is usually given as four treatments over 12 weeks – one treatment every three weeks.

In this study, the researchers compared the usual schedule of giving paclitaxel or docetaxel every three weeks to a different schedule that gave a lower dose of paclitaxel or docetaxel every week for 12 weeks. The women who got paclitaxel every week were 27 percent more likely to be alive and free of breast cancer five years after diagnosis compared to those who received the standard paclitaxel treatment schedule. The women who got paclitaxel every week also were more likely to be alive five years after diagnosis compared to women who got Docetaxel (either weekly or every three weeks). Albumin-bound or nab-paclitaxel was not looked at in this study.

For each medicine and treatment schedule the chances of being alive five years after diagnosis are:

• Paclitaxel once a week: 89.7 percent
• Paclitaxel once every three weeks: 86.5 percent
• Docetaxel once every three weeks: 87.3 percent
• Docetaxel once a week: 86.2 percent

Some doctors have wondered whether a taxane has benefits for women diagnosed with hormone-receptor-positive breast cancer. This study found that women diagnosed with hormone-receptor-positive breast cancer did benefit from getting a taxane.

Women who got paclitaxel or docetaxel once a week instead of every three weeks seemed to have less severe side effects from the chemotherapy. This is probably because each paclitaxel or docetaxel dose was slightly less than half the standard dose. On the other hand, these women had to get treatment every week instead of every three weeks. It may be harder to plan your life around getting treatment every week than getting treatment every three weeks.

According to Alan Christopher, a Consumer Safety Advocate with Consumer Safety Watch, "Patients undergoing chemotherapy treatment that involves a taxane should be advised of this information and warned about potential side effects before being treated with docetaxel which is also linked to a risk of permanent or persistent hair loss."

If chemotherapy that includes a taxane is going to be a part of your treatment plan, you might want to talk to your doctor about this study and consider asking these questions:

• Which taxane (paclitaxel, docetaxel, or Albumin-bound or nab-paclitaxel) is recommended for me? Why?
• Which treatment schedule (weekly or every three weeks) is recommended? Why?