T-DM1 Produces Promising Results Against Advanced HER2-Positive Breast Cancer

Among women with metastatic, HER2-positive breast cancer, trastuzumab emtansine (T-DM1)—an investigational drug that combines HerceptinR (trastuzumab) and a chemotherapy drug—resulted in better progression-free survival than standard chemotherapy and Herceptin. The results of this Phase II clinical trial were presented at the 2011 European Multidisciplinary Cancer Congress.??

Approximately 20-25% of breast cancers overexpress (make too much of) the HER2 protein. HER2-targeted therapies such as Herceptin have dramatically improved outcomes for women with HER2-positive breast cancer, but researchers continue to explore new approaches to treatment.???

T-DM1 links Herceptin with a chemotherapy drug (DM1). T-DM1 delivers Herceptin and DM1 directly to HER2-positive cells, and limits exposure of the rest of the body to the chemotherapy.??

To evaluate T-DM1 for the initial treatment of metastatic, HER2-positive breast cancer, researchers conducted a Phase II clinical trial among 137 women. Study participants were treated with either T-DM1 or Herceptin plus TaxotereR (docetaxel).??

Survival without cancer progression was 14.2 months among women in the T-DM1 group and 9.2 months among women in the Herceptin plus Taxotere group.?In addition to delaying cancer progression, T-DM1 was also better tolerated by patients. Discontinuation of treatment due to side effects occurred in 7.2% of women in the T-DM1 group and 28.8% of women in the Herceptin plus Taxotere group.?

These results suggest that T-DM1 may be safe and effective for the treatment of advanced, HER2-positive breast cancer. Results from ongoing Phase III trials will provide additional information about this drug.?

Reference: Hurvitz S, Dirix L, Kocsis J et al. Trastuzumab emtansine (T-DM1) vs trastuzumab plus docetaxel (H+T) in previously untreated HER2-positive metastatic breast cancer (MBC): primary results of a randomized, multicenter, open-label phase II study (TDM4450g/BO21976). Presented at the 2011 European Multidisciplinary Cancer Conference. Stockholm, Sweden. September 23-27, 2011. Abstract 5001.?

Posted October 5, 2011?

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Breast Cancer Risk after False-Positive Screening Results

Women with false-positive test results for breast cancer may want to remain vigilant with screening, as false-positive results could be associated with underlying pathology that may result in breast cancer, according to the results of a study published in the Journal of the National Cancer Institute.[1]???

A mammogram is an X-ray of the breast. Screening mammography is performed in a woman without breast symptoms in order to detect breast cancer at an early stage when it is most easily treated. Different groups of experts have reached different conclusions about when mammographic screening should begin and how often it should be performed. The U.S. Preventive Services Task Force recommends that routine screening of average-risk women begin at age 50 and be performed every two years. The American Cancer Society recommends annual screening beginning at age 40.?

Although screening mammography can reduce the risk of death from breast cancer (due to early detection), disease screening in healthy individuals can also lead to false-positive test results. A false-positive result suggests that cancer may be present even though the person is actually cancer-free. False-positive results can lead to anxiety and unnecessary additional testing.?

Women with false-positive mammography results are usually referred back for routine screening; however, it is unknown whether these women have a higher long-term risk for breast cancer compared to women who initially test negative. ?

In order to determine if women with false-positive mammography results have a higher risk of developing breast cancer than those who test negative, researchers from the University of Copenhagen evaluated data from a population-based mammography program in Copenhagen, Denmark from 1991-2005. They used the data to measure the risk of breast cancer and ductal carcinoma in situ (DCIS) in 58,003 women between the ages of 50-69 who had received false-positive test results. ?

The results indicated that women who had tested negative for breast cancer had an absolute cancer rate of 339 per 100,000 person-years at risk, whereas women had tested false-positive had an absolute rate of 583 per 100?000 person-years at risk. Six or more years after the test, the relative risk of breast cancer in women with false-positive results was statistically significantly higher than women who tested negative; however, those statistics lowered when new screening technology was introduced in the year 2000. ?

It’s important for women to discuss screening options with their physician in order to determine their optimal screening protocol for breast cancer. Based on the results of this study, women with false-positive mammography results may benefit from close monitoring and continued regular screening.?????

Reference:?

[1] Euler-Chelpin MV, Risor LM, Thorsted BL, et al. Risk of breast dancer after false-positive test results in screening mammography. Journal of the National Cancer Institute. Published early online April 5, 2012: doi: 10.1093/jnci/djs176?

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Femara Results in Lower Risk of Breast Cancer Recurrence Than Tamoxifen

Among postmenopausal women with early-stage, hormone receptor-positive breast cancer, five years of hormonal therapy with FemaraR (letrozole) results in a lower risk of cancer recurrence than five years of tamoxifen. These results were published in Lancet Oncology.?

The majority of breast cancers are hormone receptor-positive. These cancers are stimulated to grow by the circulating female hormones estrogen and/or progesterone. Treatment of hormone receptor-positive breast cancer often involves hormonal therapies that suppress or block the action of estrogen. These therapies include tamoxifen as well as drugs known as aromatase inhibitors, such as Femara. Tamoxifen acts by blocking estrogen receptors, whereas aromatase inhibitors suppress the production of estrogen in postmenopausal women.?

The Breast International Group (BIG) 1-98 Trial is a Phase III clinical trial involving over 8,000 postmenopausal women with hormone receptor-positive early breast cancer. The women were assigned one of four different approaches to hormonal therapy:??

Five years of tamoxifen?Five years of Femara?Two years of Femara followed by three years of tamoxifen?Two years of tamoxifen followed by three years of Femara?

Previous results from this study showed that five years of Femara resulted in a lower risk of breast cancer recurrence than five years of tamoxifen, and that sequential treatment with the two drugs (Femara followed by tamoxifen or tamoxifen followed by Femara) did not appear to be superior to Femara alone.??

Study participants continue to be followed in order to assess longer-term outcomes. The women have now been followed for a median of just over eight years.?

At eight years, the percentage of women alive and free of cancer was 73.8% among women assigned to five years of Femara and 70.4% among women assigned to five years of tamoxifen.?Overall survival was 83.4% among women assigned to five years of Femara and 81.2% among women assigned to five years of tamoxifen.?Sequential treatment with Femara and tamoxifen did not appear to be more effective than Femara alone.?

For postmenopausal women with hormone receptor-positive breast cancer, these results continue to suggest that five years of Femara is more effective against breast cancer recurrence than five years of tamoxifen. Sequential treatment with the two drugs may be a useful strategy for some women.?

Reference: Regan MM, Neven P, Giobbie-Hurder A et al. Assessment of letrozole and tamoxifen alone and in sequence for postmenopausal women with steroid hormone receptor-positive breast cancer: the BIG 1-98 randomised clinical trial at 8.1 years median follow-up. Lancet Oncology. 2011;12:1101-1108.?

Posted November 9, 2011

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