Over the past 30 years, more than 80 new systemic therapies for cancer have been approved, and many patients diagnosed with localized disease have benefited with improved progression-free and overall survival. The same can be said for some – but by no means all – patients with metastatic disease at diagnosis, a new study indicates.
comment the authors, led by Marianne Luyendijk, MSc, from the Netherlands Comprehensive Cancer Organization, Utrecht.
The study was published online in the Journal of the National Cancer Institute.
The retrospective study compared survival data of patients with de novo metastatic disease diagnosed from 1989 through 1993 with those of patients diagnosed from 2014 to 2018.
The results show that 5-year survival increased by 15% or more among patients with metastatic gastrointestinal stromal tumors; neuroendocrine tumors; melanoma; and cancers of the prostate, breast, thyroid, and testes.
For patients with other cancers, however, the gains in survival were more modest. For example, over the study period, 5-year survival of patients with metastatic non–small cell lung cancer increased by only 6%, a disappointing finding, given the advent of targeted therapies and immunotherapy during the most recent period, the authors note.
In contrast, there was a 16% improvement in long-term survival of patients with metastatic melanoma, likely owing to the introduction of immune checkpoint inhibitors and targeted therapies, such as tyrosine kinase inhibitors.
The data also showed differences over time in the proportion of patients diagnosed with de novo metastatic disease; some cancers, such as NSCLC and small cell lung cancer, were more frequently diagnosed at late stages in the more recent era, possibly owing to increased screening and the use of technology such as FDG-PET imaging.
On the other end of the spectrum, cancers of the prostate, rectum, uterine cervix, breast, gallbladder, and bile ducts were more likely to be caught at an earlier stage during later years of the study period.
The authors say that among the possible explanations for a less than robust reduction over time in metastatic disease is that new drugs do not always translate into improved survival. They cite a 2017 study showing that among 53 new cancer drugs approved by U.S., European, or Australian drug regulators, fewer than half improved overall survival by at least 3 months, and an additional 26% offered survival advantages that were either shorter than 3 months or of unknown benefit.
“This may also explain why the 1- and 5-year survival rates of some cancers have changed little in the last 30 years,” they write. “Nevertheless, even minor benefits in survival or other outcomes (for example, quality of life) may represent progress in treating patients with metastatic cancer.”
The investigators recommend that to improve understanding of the effect of new therapies on survival of metastatic disease, cancer registries include data on therapies used beyond the first line, as well as comorbidities and quality-of-life measures.
The authors did not report a study funding source. Ms. Luyendijk has disclosed no relevant financial relationships. Several co-authors reported financial relationships with pharmaceutical companies.
A version of this article first appeared on Medscape.com.