Herceptin: Early Stage and Short Term Use

[tousled1]

Targeted Cancer Treatments

Perhaps the most important breakthrough in cancer treatment over the past few years has been the introduction of so-called "targeted" therapies. Rather than the sledgehammer effect achieved by traditional therapies, the newer targeted therapies are designed to home in on cancer cells like a missile while leaving the healthy cells untouched. As a result, these agents lack many of the severe side effects associated with chemotherapy.

Herceptin, an effective targeted therapy for breast cancer, attaches to a protein on the surface of breast cancer cells called HER2 that transmits growth-stimulating signals to cells. By blocking the actions of HER2, Herceptin slows or stops the growth of tumor cells. Herceptin is effective in tumors that express large amounts of the HER2 protein (described as HER2-positive), which is the case in about 25% of patients.

Results from several trials of Herceptin in early-stage breast cancer have confirmed the striking effectiveness of this agent when used with or after chemotherapy. However, the results are preliminary, and further studies are needed to determine the best way to combine Herceptin with chemotherapy, how long to give it, and which patients might benefit the most.

At the breast cancer meeting, Dennis Slamon, MD, presented results from a large international trial that evaluated three treatment regimens, two of which contained Herceptin. Both of the Herceptin-containing treatments were more effective in reducing disease recurrence than the non-Herceptin-containing regimen. However, an increased risk of heart problems was seen in both Herceptin-containing groups. Adriamycin, a chemotherapy agent used in one of the Herceptin containing treatments, has also been linked to heart-related side effects -- making researchers particularly cautious about combining Adriamycin with Herceptin. Therefore, it was encouraging to see that both of the Herceptin-containing regimens -- one containing Adriamycin and the other not -- were effective.

This study also identified certain genetic changes in breast tumors that may indicate increased susceptibility of the tumor -- meaning a better response -- to Adriamycin treatment. In patients with these types of tumors (about 30% of the patients tested), researchers suggested that the added risk of heart problems from Herceptin and Adriamycin might be worthwhile given the superior treatment effect, although these data need further confirmation.

One question that remains unanswered with regard to Herceptin is how long patients should keep taking the drug. Given the high cost and the potential for rare but serious heart side effects, it is important to know if patients would also benefit from a shorter course of the therapy. An intriguing study presented at the meeting found that Herceptin given for only nine weeks alongside a chemotherapy regimen was also able to decrease breast cancer recurrence. The tentative conclusion of the study indicated that short-term use of Herceptin appears to be effective and may be better tolerated than a longer one-year regimen.

[saleboat]

Kate--

Thanks for posting this.

I think one of the other unresolved questions is what additional benefit is gained by giving the chemo + Herceptin on a dose dense schedule. The big studies were on a traditional, three week schedule. I'm under the impression that A/C & T given on a dose dense schedule is very effective against Her2 disease.

Jen

[Jean]

Kate,

Do you know of any patients taking herceptin without chemo -
Just the herceptin?

Thanks,
Jean

[tousled1]

I have not yet had my surgery as I am on neoadjunct chemo. I will be having surgery probably in early-mid June. My oncologist already told me that I will be on a year of herceptin (only herceptin) after surgery. It will be administered every 3 weeks. Hope this helps.