What is science doing to improve the health and lives of cancer survivors?
On Sunday, it was National Cancer Survivors Day in the US. The organizers describe the annual event as "an opportunity for all people living with a history of cancer - including America's nearly 14 million cancer survivors - to connect with each other, celebrate milestones and recognize those who have supported them along the way."
The event is a celebration of life, intended to symbolize to the world "that life after a cancer diagnosis can be meaningful, productive and even inspiring."
National Cancer Survivors Day (NCSD) is perhaps unique among cancer awareness campaigns in recognizing the physical, emotional and financial hardships that the disease leaves in its wake.
"The effects of cancer don't simply end when treatment does," NCSD reminds. The organization points out that many cancer survivors are denied health and life insurance coverage and may experience difficulty finding jobs, while personal relationships are prone to straining under the weight of the associated emotional struggles and ever-present fear of the cancer returning.
And the campaign has become more relevant than ever in the past few days, thanks to the publication of new research from the American Cancer Society (ACS).
Cancer survivorship is increasing, despite decreasing cancer incidence
Currently, the number of cancer survivors in the US is estimated to be 14.5 million. But the ACS believe that by 2024 this figure will have grown to almost 19 million.
Fast facts about cancer survivorship
- Nearly half of cancer survivors are aged 70 or older, with just 1 in 20 aged under 40.
- Among men with a history of cancer, the most common cancers are prostate (43%), colorectal (9%) and melanoma (8%).
- Among women survivors, the three most common cancers are breast (41%), uterine (8%) and colorectal (8%).
In fact, even though the incidence rates for cancer have been decreasing over the past decade, the number of cancer survivors is growing. This is because people are living longer with cancer and because of more effective cancer treatments.
Despite being the second most commonly diagnosed cancer in both men and women, lung cancer - because of a low survival rate - is the eighth most represented cancer among survivors. Lung cancer is the leading cause of cancer death.
Women cancer survivors in particular are at risk of a variety of adverse health outcomes. As well as the dangers presented to fertility not only by the cancer itself but also by chemotherapy, an excess of estrogen can also lead to cancer returning.
Recent studies have provided new hope to female cancer survivors on both of these fronts, however.
Firstly, a new type of anti-estrogen drug has shown promise in a recent trial, the results of which were published in the New England Journal of Medicine.
Aromatase inhibitors to delay breast cancer recurrence in women
Exemestane is a member of a class of drugs called aromatase inhibitors. The new study suggests that these drugs may be more helpful in preventing the return of cancer in women than the current recommended treatment, a drug called tamoxifen that is used to block estrogen.
Aromatase inhibitors prevent hormones changing into estrogen, the female hormone that can fuel breast cancer growth.
Aromatase inhibitors work by preventing hormones changing into estrogen, which reduces the risk of cancer recurrence because estrogen can fuel breast cancer growth.
In 2003, the International Breast Cancer Study Group initiated the Tamoxifen and Exemestane Trial (TEXT) phase 3 trial. The 4,690 participants in the trial were premenopausal women with operable breast cancer, and 12 weeks into the study they were randomized into groups that were administered either tamoxifen or exemestane.
The participants were followed for 5 years. During this period, 91.1% of the women in the exemestane group and 87.3% of the women in the tamoxifen group remained free of cancer.
Compared with the tamoxifen group, there was a 34% lower risk of breast cancer recurrence in the exemestane group. Also, in women for whom cancer did return, there was a 22% decrease in the risk of cancer spreading to other parts of the body.
Although the exemestane group experienced a delay in recurrence of cancer, overall survival during the 5-year period was slightly improved in the tamoxifen group. In the tamoxifen group, 96.9% of the participants survived the study period, and 95.9% of the exemestane group survived.
One of the authors, Dr. Olivia Pagani - clinical director of the Breast Unit at the Oncology Institute of Southern Switzerland in Bellinzona, Switzerland - explained to Medical News Today why the study did not show a more significant difference between the two treatments in terms of survivability:
"It's very difficult to achieve a significant difference in survival at this early point in time (5.7 years median follow-up) in hormone sensitive breast cancer, a disease in which recurrences can occur late in follow-up. The survival is overall very good in both tamoxifen and exemestane - over 96%, which is very good news in young women traditionally considered at high risk. And this is true also in a subset of lower risk women who did not receive chemotherapy."
Tamoxifen can be taken in premenopausal women without suppressing the function of their ovaries. Aromatase inhibitors are not effective in women with functioning ovaries, so their ovaries must also be suppressed when they are administered drugs such as exemestane.
The trade-off, Dr. Pagani explained, is that exemestane in combination with ovarian suppression is more effective than tamoxifen.
The aromatase inhibitor "significantly delays the time of appearance of a local, regional, distant relapse, of a controlateral breast cancer, second tumors and death. The relative improvement is in the magnitude of 28%, which is comparable with what was seen with aromatase inhibitors in postmenopausal women."
The researchers believe that these findings on aromatase inhibitors will encourage some physicians to change their treatment plans, but they predict that change will not be widespread until more time has elapsed. Over time, scientists will be better able to measure survivability and see how it compares to the standard tamoxifen treatment.
Hormonal therapies to improve fertility chances of cancer survivors
A new National Institutes of Health trial has also examined using gonadotropin-releasing hormone agonists to protect the ovaries of women receiving chemotherapy and so improve the fertility chances of cancer survivors.
About 16,000 American women under the age of 45 get breast cancer every year and infertility is one of the biggest problems facing these cancer survivors.
Currently, female cancer patients due to undergo chemotherapy who wish to improve their chances of fertility usually have eggs removed from their ovaries, which are then frozen or used to create embryos.
This technique is similar to in vitro fertilization, but at a cost of $10,000 or more, it is expensive. Also, some patients are required to undergo chemotherapy quickly, so they may not have time to undergo the 2-3 week egg retrieval process.
The new trial investigated whether monthly injections of a gonadotropin-releasing hormone agonist called goserelin could instead protect women's ovaries from the damage caused by chemotherapy, ensuring fertility for survivors without requiring invasive techniques.
The participants were 257 premenopausal women undergoing chemotherapy. At a follow-up of 2 years, 22% of the participants in the group not receiving the goserelin experienced ovarian failure, compared with just 8% in the group receiving goserelin injections.
What is more, 21% of the participants in the goserelin group became pregnant, with 15% having babies, while only 11% in the control group became pregnant and only 7% had babies. The researchers say that the disparity cannot be explained by a difference between the groups of participants who attempted to conceive.
About 16,000 American women under the age of 45 get breast cancer every year, and infertility is one of the biggest problems facing these cancer survivors.
Campaigns such as National Cancer Survivors Day drive forward research
In the conclusion to her report on survivorship rates, ACS epidemiologist Carol DeSantis, MPH, summarizes the problems faced by cancer survivors in the US:
"Despite the fact that awareness of survivorship issues has increased, cancer survivors face numerous, important hurdles created by a fractured health care system, poor integration of survivorship care, and financial and other barriers to quality care, particularly among the medically underserved."
"An important first step in addressing these challenges is to identify 'best practices' for the delivery of quality post-treatment cancer care," she adds.
Awareness campaigns such as NCSD act as an annual reminder to policymakers not to neglect this group. But as well as raising awareness of the problems faced by cancer patients in the aftermath of the illness, NCSD also actively campaign for more resources, research and survivor-friendly legislation to improve the quality of life of cancer survivors.
What shape might this new research take? We asked Dr. Pagani for her thoughts on what the future holds for treatments that could improve quality of life or reduce risk of cancer recurrence in survivors.
She told us:
"The future, in my opinion, is in tailoring treatments according to specific biologic characteristics of the tumors, which is, for example, still a problem in triple negative breast cancer. The journey is still long, but worldwide collaboration in research has shown - for example, with our trials - that it is possible to answer important questions in selected patients' populations."
See the ACS website for more resources and information aimed at helping survivors of cancer.
Written by David McNamee
Copyright: Medical News Today
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