Doctors have long known that many early-stage breast cancer patients who get chemotherapy don't actually need it to prevent recurrence of the disease after surgery. But they haven't known exactly which patients might safely skip the toxic treatment.
A European study published Wednesday in the New England Journal of Medicine sheds new light on the issue, concluding that many such patients might be able to avoid chemo.
The key factor: Nearly half of the patients considered at high risk for recurrence might actually be low risk based on genetic factors, researchers found.
The study involved almost 6,700 patients with localized breast cancer that hadn't spread beyond three lymph nodes. Of those, about half were considered high risk based on clinical measures such as tumor size and patient age. Typically, all would have received chemotherapy as part of their treatment.
But a 70-gene test called the MammaPrint test found that about 1,500 of that group were low risk based on genomic factors. They were considered "discordant" -- high-risk patients based on clinical factors, but low risk based on gene-test results.
The 1,500 women then were put randomly into two groups, with one getting chemo and one not getting it. After five years, the survival rates of the groups were similar -- just 1.5 percentage points higher for the women who'd received chemo. The survival rate for the non-chemo group was close to 95 percent.
Given those findings, the researchers say, about 46 percent of women with breast cancer who are classified as high risk based on clinical factors might not need chemo.
Study co-author Laura van 't Veer, a molecular biologist and leader of the breast oncology program at the Helen Diller Family Comprehensive Cancer Center at the University of California at San Francisco, did the research that led to the gene test while working for the Netherlands Cancer Institute.
Van 't Veer, who is an officer in the company now marketing the test, said MammaPrint "looks under the hood of the tumor and into the engine of the cancer to show whether the biology is truly aggressive and has capacity to invade surrounding issue."
She said the 1.5 percentage-point difference in survival rates between women who got chemo and the ones who didn't was not statistically significant, especially considering the side effects of chemo, which can include fatigue, cognitive impairment and a prolonged disruption in schedule.
But Paul Kelly Marcom, a breast cancer oncologist at Duke Cancer Institute, said that whether that survival-rate difference is significant is a personal decision by a woman and her doctor.
He also noted that there are other genomic tests on the market and that physicians are in the early stages of learning how to use them. "It's not a quick or easy process," he said, adding that he thinks physicians need more data before making big changes in clinical practice.
Another test, called Oncotype DX, came on the U.S. market earlier and is more widely used. But it analyzes a smaller set of genes than MammaPrint and is used for only certain types of breast cancer.
Both Oncotype DX and MammaPrint cost about $4,000. In many cases, Marcom said, insurance covers the tests.
An accompanying editorial said the trial showed "how a well-coordinated and highly collaborative multinational team of investigators can efficiently conduct a potentially practice-changing study."
It said the results "could allow some doctors and patients to choose to avoid chemotherapy if they have carefully considered their own tolerance for toxicity, risk, and uncertainty." Yet such decisions are "highly individualized."
The European study was called MINDACT for Microarray for Node-Negative Disease May Avoid Chemotherapy Trial. Some of the information was released in April at the American Association for Cancer Research annual conference.
The Washington Post
Thu Aug 25 2016
Nearly half of the patients considered at high risk for recurrence might actually be low risk based on genetic factors, researchers found.
Iran's supreme leader says Hamas leader's death will not halt 'Axis of Resistance'
The "Axis of Resistance", built up with years of Iranian support, includes Hamas, the Lebanese Hezbollah group, the Houthi movement in Yemen, and various Shi'ite groups in Iraq and Syria.
Putin says Russia willing to seek compromises between Iran and Israel
Russia is ready to help seek compromises between arch-foes Israel and Iran, President Vladimir Putin said on Friday, saying these would be difficult but possible.
What proposals will Russia push at the BRICS summit?
The proposal is also to establish a BRICS reinsurance company to allow uninterrupted shipment of goods and key commodities between members.
Indonesia's free meals plan in the spotlight as Prabowo readies for office
Prabowo calls the programme one of the main drivers of economic growth, eventually set to add an estimated 2.5 million jobs.
Astro AWANI's revamped English news website, AWANI International, launches on Oct 21
Astro AWANI's revamped English platform delivers in-depth global news and expert analysis to keep you informed on key developments.
Israeli strikes kill 33 people in Jabalia refugee camp in Gaza, medics say
Residents of Jabalia said Israeli tanks had reached the heart of the camp after pushing through suburbs and residential districts.
Liam Payne's ex-partner calls for media restraint after 'painful' death
Cheryl Tweedy used her statement to urge the media to remember they had a seven-year-old son, Bear, who could read the reports.
Analysts: Indonesia's strong MoF leadership team to boost investor confidence
Sri Mulyani Indrawati as head of Indonesia's Ministry of Finance is expected to instil confidence among investors.
Biden offers both a carrot and a stick to Israel as his term nears an end
Israel has frequently resisted US advice and has caused political difficulties for the Biden administration.
Putin says BRICS will generate most of global economic growth
Russian President Vladimir Putin will host a summit of the group in the city of Kazan on Oct. 22-24.
ISIS Malaysia's perspective of Budget 2025
An excellent rakyat-centric budget under the overarching principle of a caring and humane economy.
Budget 2025: Record increase in STR, SARA aid initiatives
The government will provide a significant boost to the Sumbangan Tunai Rahmah (STR) and Sumbangan Asas Rahmah (SARA) initiatives next year.
Budget 2025: EPF contributions to be made mandatory for foreign workers – PM Anwar
The government plans to make it compulsory for all non-citizen workers to contribute to the Employees Provident Fund (EPF).
What policies to expect from Indonesia's new President Prabowo
Prabowo will be open to foreign investment, his aide has said, such as by offering investors management of airports and sea ports.
Budget 2025: Govt allocates RM470 mil to empower women's participation in PMKS
The Women's Leadership Apprenticeship Program will be intensified as an effort to produce more female corporate personalities.
Israel sends more troops into north Gaza, deepens raid
Residents of Jabalia in northern Gaza said Israeli tanks had reached the heart of the camp, using heavy air and ground fire.
Indonesia ramps up security ahead of Prabowo's inauguration
Prabowo Subianto will be sworn in as Indonesia's president on Sunday with Vice President-elect, Gibran Rakabuming Raka, also taking office.
Immediate allocation of RM150 mil for local authorities, DID to tackle flash floods
Datuk Seri Anwar Ibrahim said this allocation is intended to address the recent flash floods that hit the capital and several major towns.
Budget 2025: Sabah, Sarawak to continue receiving among highest allocations - PM
Sabah and Sarawak continues to be prioritised under Budget 2025, with allocations of RM6.7 billion and RM5.9 billion respectively.
NFOF will be operational in November 2024 with funding of RM1 bil
PM Anwar Ibrahim said NFOF will support venture capital fund managers to invest in startup companies with RM300 million set aside for 2025.