Two new studies published in The Lancet have highlighted that two different generic drugs – aromatase inhibitors (AIs) and bisphosphonates – which can help improve the prognosis of early breast cancer in menopausal women. If used in combination, scientists claim that the drugs could be more beneficial with the least amount of side-effects.
Cheap Drugs For Breast Cancer Treatment
Most women develop breast cancer after they become menopausal. If detected in its early stages, surgery can effectively remove all the diseased tissue. However, surgical intervention might leave behind certain dangerous and undetected micrometastases (small secondary tumors). About 80 percent of all breast cancers are hormone sensitive (ER-positive) – they can be stimulated by bodily hormones such as estrogen. In these cases, hormone therapy or endocrine treatments (inhibiting hormones from stimulating cancer cells) prove highly effective in the prevention of breast cancer from recurring.
The Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) is a global collaboration established by researchers from the University of Oxford (UK) 30 years ago. It collected timely evidence about treatment methods for early breast cancer from various randomized trials. The two reports mentioned here provide substantial proof of the effectiveness of AIs and bisphosphonates in treating breast cancer in premenopausal women.
Study I: Aromatase Inhibitors (AIs)
This study compiles evidence from 30,000 postmenopausal women from nine randomized trials. It showed that the survival rates of these women had significantly improved after five years of endocrine therapy with aromatase inhibitors (AIs), as opposed to the traditional therapy with tamoxifen. Furthermore, AI therapy reduced recurrence rates by 30 percent and the likelihood of death by about 15 percent. Compared to receiving no endocrine therapy, researchers claim that the risk of dying from breast cancer within ten years would be reduced by 40 percent in women taking AI therapy.
Lead author Professor Mitch Dowsett of The Royal Marsden and The Institute of Cancer Research, London, UK stated that the five year AI therapy showed extremely positive results as compared to tamoxifen. He highlighted the specificity of AI – removing only the minute amounts of estrogen that remain in the body after menopause. However, he also commented on the potential side-effects of the treatment, and how constant monitoring and maintenance was vital.
Study II: Bisphosphonates
The second study compiles evidence from 20,000 women enrolled in 26 randomized trials. It provides evidence that two to five years of therapy with bisphosphonates – originally used to treat osteoporosis – decreases the likelihood of breast cancer recurrence, and also improves survival rates in post-menopausal women. However, little effect was seen of the treatment in premenopausal women.
Breast cancer cells commonly spread to the bone. Cells released from the primary tumor can remain dormant for several years once they reach the bone and other parts of the body. Bisphosphonates change the microenvironment of the bone, making it less favorable for the development of cancer cells and hence reducing its recurrence. To prove this scientifically, a meta-analysis of individual patient data from 18,766 women in 26 randomized trials were analyzed. The effects of receiving bisphosphonate therapy for two to five years were seen.
The only clear results were a 17 percent reduction in cancer cells recurring in the bone. More promising results were seen among postmenopausal women – 28 percent reduction in bone recurrence and 18 percent reduction in the risk of death from breast cancer during first ten year of diagnosis. Moreover, these benefits were irrespective of the type of bisphosphonate used, duration of therapy, size of tumor and its spread, and whether it was ER-positive or not. Furthermore, the therapy did not reduce the risk of new cancers developing the adjacent breast.
Professor Robert Coleman from the University of Sheffield, UK, was the lead author of the bisphosphonate study. He commented that the findings reveal diverse uses of the latter – apart from treating bone loss and fractures in postmenopausal women. According to him, the simple and well-tolerated therapy should be considered for regular practice in the treatment of breast cancer in its early stages, since it was effective in enhancing survival rates and reducing adverse side-effects as seen in other therapies.
Professor Richard Gray from the University of Oxford, UK, the lead statistician for both studies commented that they provided good evidence regarding the use of these inexpensive drugs for treating and managing early breast cancer in postmenopausal women.
“About two-thirds of all women with breast cancer are postmenopausal with hormone-sensitive tumors, and could potentially benefit from both drugs”. Moreover, the drugs are complementary. “The main side effect of aromatase inhibitors is an increase in bone loss and fractures, while bisphosphonates reduce bone loss and fractures along with improving survival rates”, Professor Gray added. Hence, a combination therapy would be an ideal treatment option.