Risk of breast cancer’s return looms for 20 yrs
MIAMI, Nov 9, (AFP): Women who are treated for a kind of breast cancer that is fueled by the hormone estrogen face a substantial risk of the cancer returning, even 20 years later, researchers said Wednesday.
The risk is highest in women whose original tumors were large and affected four or more lymph nodes, said the report in the New England Journal of Medicine.
Researchers analyzed data from 88 clinical trials involving nearly 63,000 women with estrogen-receptor (ER) positive breast cancer, one of the most common types.
Patients in the study all received endocrine therapy — such as tamoxifen which is the standard of care to cut the risk of cancer recurrence — for five years and were free of cancer when they stopped therapy.
But researchers found a “steady” risk of tumors recurring over the next 15 years, up to 20 years after the initial diagnosis.
“Even though these women remained free of recurrence in the first five years, the risk of having their cancer recur elsewhere — for example in the bone, liver or lung — from years five to 20 remained constant,” said senior author Daniel Hayes, professor of breast cancer research at the University of Michigan Comprehensive Cancer Center.
Women whose original tumors were large enough to have spread to four or more lymph nodes had a 40 percent risk of a cancer recurrence over the next 15 years.
For women with small, low-grade cancers and no spread to the lymph nodes, the risk of cancer recurring was 10 percent in 15 years.
“It is remarkable that breast cancer can remain dormant for so long and then spread many years later with this risk remaining the same year after year and still strongly related to the size of the original cancer and whether it had spread to the nodes,” said lead author Hongchao Pan, from the University of Oxford.
The findings raise questions about the current practice of treating women with tamoxifen or aromatase inhibitors for five years after the tumor is removed, in order to reduce the risk of a recurrence.
Some experts believe the treatment should be extended to 10 years.
Side effects can include hot flashes, vaginal dryness, osteoporosis and joint pain.
Ultimately, the decision is up to a woman and her doctor, said Hayes.
“These data can be used by patients and their health care providers as they consider whether to continue taking anti-estrogen therapy beyond five years, weighed against side effects and toxicity of the therapies,” he said.
Treatments for breast cancer have improved in recent years, so the estimated risks of recurrence may be on the high side, said co-lead author Richard Gray, of the University of Oxford.
“To assess 20-year risks, we had to study women who received their breast cancer diagnosis many years ago,” said Gray.
“We know that treatments have improved since then, so recurrence rates will be somewhat lower for women who were diagnosed more recently.”
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MIAMI: People who are injured at night heal far more slowly because the body’s internal clock regulates the pace of healing and performs better during the day, researchers said Wednesday.
The report in the journal Science Translational Medicine found that cuts and burns healed about 60 percent faster if the injury happened during the day compared to at night.
Researchers say the body’s clock, or circadian rhythm, is the reason for the difference, because it regulates crucial body processes including sleeping, metabolism and hormone secretion.
“This is the first time that the circadian clock within individual skin cells has been shown to determine how effectively they respond to injuries,” said senior author John O’Neill,a scientist at the Medical Research Council Laboratory of Molecular Biology in Cambridge.
“We consistently see about a two-fold difference in wound healing speed between the body clock’s day and night,” he added.
“It may be that our bodies have evolved to heal fastest during the day when injuries are more likely to occur.”
The study was based on experiments using both live mice and human skin cells in a lab dish, and was corroborated with records of 118 burn patients from major burn units in England and Wales.
Nighttime burns — happening between 8 pm and 8 am — took an average of 60 percent longer to heal. Burns incurred at night were 95 percent healed after an average of 28 days, said the report.
Daytime burns healed in just 17 days, on average, because skin cells moved to the site of the wound to repair it with proteins like actin and collagen much faster during the day.
The same process was apparent in mice and human cells in a lab dish, suggesting that the body’s internal circadian clock is in charge of this process.
“Further research into the link between body clocks and wound healing may help us to develop drugs that prevent defective wound healing or even help us to improve surgery outcomes,” said lead author Ned Hoyle, also from the MRC Laboratory of Molecular Biology.