Recurrence Risk Suggests Extended Treatment for Some Early Stage Breast Cancer
HOUSTON, Aug. 13 (MedPage Today) -- For early breast cancer patients, hormone-positive status may forecast the need for extended treatment to prevent late recurrence, researchers here said.
Residual risk of recurrence was 11% at five years and 20% by 10 years overall among women who were disease-free five years after treatment, reported Abenaa M. Brewster, M.D., of the University of Texas M.D. Anderson Cancer Center, and colleagues online in the Journal of the National Cancer Institute.
In the retrospective registry study, risk of recurrence was significantly greater for those with hormone-positive tumors (P<0.001), the researchers said.
Extended adjuvant endocrine therapy is recommended for postmenopausal women with hormone-responsive breast cancers, although there are no therapeutic options for premenopausal women who have completed five years of tamoxifen.
"However, limitations in the ability to predict the magnitude of the risk of late recurrence may contribute to some patients receiving unnecessary extended adjuvant endocrine therapy and others receiving no treatment," Dr. Brewster's group noted.
The magnitudes of residual risk for both pre- and postmenopausal patients in the study -- 8% to 20% -- were in the range considered appropriate to recommend adjuvant and neoadjuvant therapy at the time of diagnosis, they said, "indicating a need for the continued development of risk reduction strategies for these survivors."
To see what residual risk remained after therapy, the researchers analyzed data for 2,838 women in the M.D. Anderson Tumor registry who were treated for stage I, II, or III disease from 1985 through 2001 and remained disease free for at least five years from the start of adjuvant or neoadjuvant therapy.
Five years was used as the start of disease recurrence follow-up because most women with hormone-positive tumors received five years of adjuvant endocrine therapy, the researchers said.
Recurrence -- local node or breast recurrence, metastasis, or second primary breast cancer -- occurred in 216 women during a median of 28 months of follow-up after five years from the start of adjuvant or neoadjuvant therapy.
Recurrence-free survival rates at 10 and 15 years after the start of therapy were 89% and 80%, respectively.
Patients with higher stage disease had a greater likelihood of late recurrence. At five years after the end of treatment, the residual recurrence risk was:
- 7% for patients with stage I disease (95% confidence interval 3% to 15%).
- 11% for patients with stage II disease (95% CI 9% to 13%).
- 13% for patients with stage III disease (95% CI 10% to 17%).
Patients with hormone-positive tumors were also at greater risk (P<0.001).
Recurrence-free survival at five years after completion of adjuvant or neoadjuvant therapy was 87.0% for hormone receptor-positive cancer (95% CI 84.3 to 89.2) compared with 92.9% (95% CI 89.7 to 95.1). At ten years after therapy, survival was 76.9% (95% CI 71.3 to 81.6) and 88.7% (95% CI 83.2 to 92.4), respectively.
Even when patients with hormone-positive tumors received endocrine therapy, they tended to be more likely to have recurrence than those with hormone-negative tumors (hazard ratio 1.49, P=0.084).
In the multivariate analysis, factors associated with increased risk of recurrence five years after the start of adjuvant or neoadjuvant therapy were:
- Higher stage disease (HR 2.49 for stage III versus stage I, P=0.004, and 2.13 for stage II versus stage I, P=0.009).
- Hormone-positive tumors not treated with endocrine therapy compared with hormone receptor-negative tumors (HR 1.84, P=0.006).
The researchers noted that the study was limited by lack of data on HER2/neu expression and the few patients who received aromatase inhibitors as adjuvant therapy during the study period.
One of the researchers reported receiving research funding from Novartis and AstraZeneca.
Primary source: Journal of the National Cancer Institute Source reference: Brewster AM, et al "Residual Risk of Breast Cancer Recurrence 5 Years After Adjuvant Therapy" J Natl Cancer Inst 2008; 100: DOI: 10.1093/jnci/djn233.
What breastcancer.org says about this article…
Recurrence Risk Suggests Extended Treatment for Some Early Stage Breast Cancer
The study reviewed here shows that there is a risk of breast cancer coming back (recurrence) even many years after surgery and other treatments to reduce that risk.
The researchers looked at the health histories of almost 3,000 women who didn't have early-stage breast cancer come back during the 5 years after diagnosis and initial treatment. Breast cancer that comes back within 5 years of diagnosis and initial treatment is called "early recurrence." Breast cancer that comes back more than 5 years after diagnosis and initial treatment is called "late recurrence."
Ten years after initial diagnosis and treatment, 11% of the women in the study had a late recurrence. At 15 years after initial diagnosis and treatment, 20% of the women had a late recurrence.
The study showed that the risk of late recurrence was more likely when:
- the cancer was later stage at the time of diagnosis; the risk of late recurrence at 10 years after initial diagnosis and treatment was:
- 7% with stage I cancer
- 11% with stage II
- 13% with stage III
- the breast cancer was hormone-receptor-positive
This research strongly suggests that ALL women diagnosed with breast cancer need to talk to their doctors about steps they can take to reduce the risk of both early and late recurrence.
If you're newly diagnosed with early-stage breast cancer:
- Talk to your doctor about how chemotherapy and radiation therapy after surgery can help lower the risk of breast cancer coming back. If the cancer is HER2-positive, ask your doctor if Herceptin would be a good option for you.
- If you're a pre-menopausal woman diagnosed with hormone-receptor-positive cancer, talk to your doctor about treatments that reduce the effect of estrogen on the risk of the cancer coming back. Possible treatments include taking tamoxifen, taking medicine to shut down the ovaries (medical ovarian shutdown), or surgically removing the ovaries (oophorectomy).
- If you're a post-menopausal woman diagnosed with hormone-receptor-positive cancer, talk to your doctor about hormonal therapy treatment after initial treatment. Tamoxifen or one of the aromatase inhibitors is usually taken for 5 years after surgery (and possibly radiation and chemotherapy) to lower the risk of hormone-receptor-positive, early-stage breast cancer coming back. The aromatase inhibitors are Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole).
If you've been diagnosed and treated for early-stage breast cancer within the last 5 years:
- Make sure you stay on track with your hormonal therapy treatment plan and take the hormonal therapy medicine for as long as it's prescribed.
- If you're taking a hormonal therapy medicine for 5 years after surgery (or recently completed 5 years of hormonal therapy) ask your doctor about the pros and cons of taking hormonal therapy longer than 5 years to continue to reduce the risk of the cancer coming back.
- Follow the breast cancer screening plan you and your doctor have created.
Besides these treatments, there are other diet and lifestyle changes you can make to keep the risk of the cancer coming back as low as it can be. Learn more in the Lowering Risk for People with a Personal History section.
