Breast Cancer Risk Of Relapse Is Not Negligible Say Researchers

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Main Category: Breast Cancer
Article Date: 13 Aug 2008 - 1:00 PDT

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US researchers estimated that the risk of relapse for breast cancer patients who were cancer-free for five years after systemic therapy (chemotherapy, hormone therapy, or both, as well as surgery) was not negligible although it was probably lower than many people realized.

The study was the work of Dr Abenaa Brewster of the University of Texas MD Anderson Cancer Center in Houston and colleagues and is published in the August 11 online issue of the Journal of the National Cancer Institute.

Brewster and colleagues wrote that women who receive adjuvant or systemic therapy (that is chemotherapy or hormone treatment, or both) as well as surgery have a higher survival rate free of cancer than women who do not have this type of treatment, but few studies have examined this post treatment period, the size of the recurrence risk, and the types of tumors that can occur.

When they explored this area, they found that for breast cancer patients who were cancer-free five years after the start of systemic therapy, 89 per cent of them survived another five years, and 80 per cent of them survived another 10 years, which was about 15 years after receiving their initial diagnosis and starting treatment.

For the study, Brewster and colleagues examined records of 2,838 breast cancer patients who were on the MD Anderson Cancer Center's tumor registry and were treated between 1985 and 2001. They looked at what happened five years after the women started treatment so they could work out the risk of relapse after adjuvant therapy, which might include five years of hormone therapy.

The study mostly predates the introduction around the year 2000 of a newer class of hormone targeting drugs, the aromatase inhibitors, which is now often used to treat hormone-sensitive tumors instead of the more traditional tamoxifen. The number of women in the study who were treated with the newer drugs was very small and the relevance of these findings for them is not clear, the researchers told WebMD.

Nevertheless, for the women in the study, the authors found that:

• 216 women developed recurrent disease after a median follow-up of 28 months.


• For women with stage I breast cancer, the five year risk of relapse was 7 per cent.


• This was 11 per cent for women with stage II cancer, and 13 per cent for women with stage III.


• Risk of recurrence was significantly linked to tumor grade, whether the cancer was hormone-sensitive, and whether hormone therapy was administered.

Brewster and colleagues concluded that:

"This study demonstrates that patients with early stage breast cancer who are disease free at five years after [adjuvant systemic therapy] have a substantially increased residual risk of recurrence."

The authors wrote that the increased risk of relapse after five years of therapy for patients with hormone-sensitive cancer "points to an area of unmet clinical need", because while options to reduce risk exist for postmenopausal women after five years on tamoxifen, there are none for premenopausal women and new strategies are needed to help these patients reduce their relapse risk.

The authors also told WebMD that the study revealed good news for women who have breast cancers that are estrogen-receptor negative (ER negative), that is their tumors do not rely on estrogen to grow. Although less common, these cancers are usually considered more deadly than the hormone sensitive type.

The study showed that patients with ER negative tumors who survived for five years after starting treatment had a better prognosis than patients with ER positive tumors, as Brewster told WebMD:

"These tumors are certainly more aggressive early on, but the outlook is good for women with these tumors who survive for five years," adding that, " we can now tell these women that their risk for developing a recurrence is lower than for women with ER-positive tumors."

"Breast Cancer Patients Still Have Risk of Relapse After Five Years of Systemic Therapy."
Journal of the National Cancer Institute Advance Access published on August 11, 2008.
doi:10.1093/jnci/djn323

Click here for Abstract.

Sources: JNCI, WebMD.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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