No more colorectal or lung cancer in phase 1 trials. Stretching the point, this could be the scenario in the near future following the trends described in an abstract presented at the International Congress on Targeted Anticancer Therapies held in Paris at the end of February 25-27, and published in a special Supplement of Annals of Oncology.
According to these data, there has been a sharp decline in the proportion of phase 1 trials recruiting patients with common malignancies like colorectal or lung cancer since the early 1990s. “We demonstrated that the uncommon cancer types are increasing as a proportion of the patients in phase 1 studies, while common cancers are decreasing markedly” said Jun Sato from the National Cancer Center Hospital, Tokio, Japan, lead author of the research. It doesn’t mean that patients with the two cancers are no more represented in clinical studies but, the proportion of phase 1 trials in which patients with either colorectal or lung cancer account for at least half of the enrolled subjects declined by almost 30 percentage points in two decades, down from 46,3% in 1991-1995 to 16,7% in 2011-2015.
Sato and colleagues Searched the PubMed database to identify single-agent phase 1 trials published from 1991 to 2015, enrolling patients with any solid tumour. “We identified 866 eligible studies, which enrolled a total of 29.112 patients with advanced solid cancers” wrote the authors, underlining that more than half of the selected trials were conducted in North America (55,5%), followed by Europe (27,8%) and Asia (10,5%). “The distribution of cancer types has change dramatically in early-phase trials, and patients with common cancers are likely not to participate” they concluded.
“Common cancers like lung adenocarcinomas are now classified into multiple rarer subtypes based on genomic markers” said Rodrigo Dienstmann of the Oncology Data Science unit at the Vall d’Hebron Institute of Oncology, Barcelona, Spain, in a press release. “This study won’t have really captured the explosion in immunotherapy trials that we have seen” he added.
As experts said, the arrival of immunotherapy represented a big revolution in cancer medicine, but data analysed by Sato come from studies published up to 2015, when immunotherapy was at it’s very beginning.
Nonetheless, despite this limitation, the analysis shed light on a clinical research vibrantly looking for new approaches for tackling cancer, including rare disease types.