Studies on HRT for breast cancer patients can give false hopes
Women treated for breast cancer who are considering taking Hormone Replacement Therapy (HRT) should be cautious when using published research to inform their decision. An article published today in the journal Breast Cancer Research reveals that qualitative studies on the recurrence of breast cancer in breast cancer survivors undergoing HRT are unreliable.
There are two main types of research studies – qualitative and quantitative. Each type is used to answer different research questions. Dr Col, from Brown Medical School, USA, and colleagues found that all of the qualitative studies on the recurrence of breast cancer in patients taking HRT they looked at have “serious design features that could introduce selection, reporting and/or publication biases”.
These qualitative studies have concluded that there is no increased risk of the recurrence of breast cancer in patients taking HRT, but the authors of today’s study feel that this is not a reliable conclusion. Meanwhile, evidence from randomized controlled trials - a type of quantitative study – suggests the opposite – that there is an increased risk of the recurrence of breast cancer in patients taking HRT.
Patients and doctors, the authors conclude, should base their decision on randomised controlled trials, as these “provide the only reliable estimates of recurrence risk”.
The authors scrutinized 10 studies on the recurrence of breast cancer in a total of 1,316 breast cancer survivors who used HRT and 2,839 who didn’t. Out of the ten studies, the eight qualitative studies were positive and suggested that HRT decreases the risk of breast cancer recurrence by 0.64. The two randomised controlled trials found the opposite and concluded that HRT increases the risk of recurrence by 3.41.
The positive studies were all said to have methodological limitations that could not be controlled using statistical methods. For example, they selected healthier women to take HRT and followed them for only a very short time. The authors also speculated that ‘publication bias’ played a role – this is where researchers and journals are more likely to publish positive results, which suggests that negative results have not been published. Overall, this bias in the reporting of results has propagated the idea of a protective effect of HRT.
Overall, the authors conclude that these qualitative studies “should be considered essentially uninformative with respect to HRT use in breast cancer survivors.”
Women who have been treated for breast cancer are usually menopausal, either because of age, the cancer itself or because of therapy. HRT offers the hope of overcoming symptoms of the menopause such as hot flushes, mood swings and increased risk of developing osteoporosis. The link between HRT and breast cancer is controversial. The present study highlights the need for extreme caution and critical judgment when looking at the evidence for or against HRT use in breast cancer survivors.
Juliette Savin | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...