The annual conference is underway in Glasgow, Scotland. Highlighted abstracts at the meeting included the following three studies.
Trading Prostate Cancer Survival for Reduced Toxicity
Men with newly diagnosed prostate cancer said they would accept reduced survival odds to avoid some of the treatment-related toxicity and adverse effects on quality of life, a survey of 634 patients showed.
At the time of the survey, the men knew they had early-stage (localized) prostate cancer but had not discussed treatment options with their doctors. Three-fourths of the men had low- or intermediate-risk disease, and the remainder had cancer associated with high-risk characteristics, said Hashim Ahmed, MD, of Imperial College London.
Each man considered two hypothetical treatment scenarios that differed in terms of likely impact on survival, effects on sexual and urinary function, recovery time, and the likelihood that additional treatment would be required. Researchers asked the men to choose one of the treatments, then repeated the request several times, varying the estimated impact on survival, adverse effects, and quality of life.
Although survival topped all other considerations, the responses showed the men would be willing to make tradeoffs between survival and side effects: 0.68% reduction in survival for each 1% improvement in the odds of retaining normal urinary function; 0.41% survival decrement in return for a 1% decrease in the likely need for additional treatment; and 0.28% survival decrement for each 1% improvement in the odds of retaining sexual potency.
"It's easy to assume that a patient's key motivation is survival, but this research shows the situation is more nuanced," Ahmed said in a statement. "Men do want long life, but they highly value treatments that have low side effects, so much so that, on average, they were willing to accept lower survival if it meant that the risk of side effects was low."
"The amount of lower survival they were willing to accept is about the same as the small benefit they might expect from radical surgery or radiotherapy instead of active surveillance," he added.
More Men Dying of Melanoma
Melanoma mortality consistently trended higher among men in a survey of 33 countries, British investigators reported.
The analysis focused on melanoma mortality from 1987 through 2015, using data from the World Health Organization mortality database. Age-standardized death rates were higher for men in all 33 countries.
For the years 2013-2015, the highest 3-year average death rates for melanoma were in Australia, where men had a rate of 5.72 per 100,000 versus 2.53 per 100,000 in women. Japan had the lowest 3-year standardized death rates for melanoma (0.24/100,000 for men and 0.18/100,000 for women. Data were unavailable to calculate the 3-year melanoma mortality for the United States and Canada.
Only in the Czech Republic did melanoma mortality among men decrease during the 30-year study period, declining by 0.7% per year, according to Dorothy Yang, MD, of the Royal Free London NHS Foundation Trust. Israel and the Czech Republic had the largest decreases in melanoma mortality among women, 23.4% and 15.5%, respectively.
"More research will be needed to explore the factors underlying these trends," Yang said in a statement. "There is evidence that suggests men are less likely to protect themselves from the sun or engage with melanoma awareness and prevention campaigns. There is also ongoing work looking for any biological factors underlying the difference in mortality rates between men and women."
Milder Radiotherapy OK for Low-Risk Thyroid Cancer
Patients with a low risk of recurrent thyroid cancer after surgery did equally well with low- or standard-dose adjuvant radioiodine ablation, results of a randomized trial involving 434 patients showed.
After a median follow-up of 6.5 years in the , 11 patients randomized to a radiation dose of 1.1 GBq () had disease recurrence versus 10 in the group that received a 3.7-GBq dose. Recurrence rates also did not differ between patients who used thyrotropin alfa (Thyrogen) or thyroid hormone withdrawal.
The results should lead to changes in clinical guidelines, allowing more patients to receive low-dose radiation therapy and avoiding some of the treatment-related side effects and long-term complications, said Jonathan Wadsley, MD, of Weston Park Hospital in Sheffield, England.
"The study showed that patients receiving a lower [radiation] activity experienced fewer side effects, in particular less risk of feeling sick or suffering damage to the salivary glands, which can potentially lead to a permanently dry mouth," Wadsley said in a statement. "The use of a lower activity also raises the possibility of giving the treatment in one day rather than having to admit patients to be nursed in isolation for two or three nights. This is required for the higher activity due to radiation protection regulations to avoid exposing the general public to unnecessary radiation, but can be particularly distressing for patients."
Primary Source
National Cancer Research Institute
Ahmed H et al "Evaluating the tradeoffs men with localized prostate cancer make between the risks and benefits of treatments: The COMPARE study" NCRI 2018; Abstract 1967.
Secondary Source
National Cancer Research Institute
Yang D et al "Trends in mortality from malignant melanoma: An observatinal study of the World Health Organization mortality database from 1985 to 2015" NCRI 2018; Abstract 1952.
Additional Source
National Cancer Research Institute
Wadsley J et al. "Recurrence rates after low-dose radioiodine ablation for differentiated thyroid cancer within the NCRI HiLo Trial." NCRI 2018. Abstract LBA 2148.