The best colorectal cancer studies at ASCO 2018

It's time for the annual meeting of the American Society of Clinical Oncology (ASCO), and for those of you who are going for the first time, you will enjoy a meeting of fantastic scientific quality. Plan to follow. Think about why you really want to go and focus. Do not exhaust yourself; instead, keep the rhythm. I can say that as a veteran of many of these meetings. But clearly, ASCO, as well as the annual meeting of the European Society of Medical Oncology (ESMO), provide excellent breaking news and high-quality work. Enjoy it.

I wanted to mention some summaries that caught my attention. In abstract 3509, Michael Geissler, MD, PhD and colleagues [1] report a very interesting study of triple chemotherapy with anti-EGFR, badyzing the combinations of a modified FOLFOXIRI regimen plus panitumumab versus FOLFOXIRI alone in initial chemotherapy line, unresectable, RAS patients with wild-type metastatic colorectal cancer.

It is a good study design in terms of how the regime moves forward. There was a 2 to 1 randomization of 96 patients. What really struck me was the extraordinary response rate in the combination arm: 85.7% versus 54.5% in the chemotherapy arm alone.

It's great that if we select patients appropriately, we can achieve response rates at this level. Clearly, this is a regimen that could be very effective in certain groups of patients. There are also some subgroup badyzes with relatively small numbers, which we should therefore treat with caution. But it is a study to take into account.

In another interesting summary, 3507, Katherine Clifton, MD, and colleagues [2] have conducted a very nice study using an intelligent methodology to examine the new number of circulating DNA copies. They looked for driver mutations in a large cohort of patients with colorectal cancer; nearly 5,000 patients underwent molecular profiles with a next-generation plasma-based sequencing baday.

The baday encompbaded driver mutations such as ROS1 RET ALK and some of the receptor fusions FGF . In this well-designed study, they found 41 patients in whom they could detect mutations of the DNA controller. It was a great effort and very well done; however, a fairly small recovery given the effort. Of course, there is still no evidence, at least in the abstract, about whether the controller mutations were of any clinical use.

This raises the question of how much work remains to be done in terms of using the next step: generation sequencing in precision medicine. There is an extraordinary potential to use gene sequencing, but can it become a significant and practical clinical benefit?

Another summary that caught my attention was 3505, reported by an excellent Italian group with the lead author, Filippo Pietrantonio, MD. [19659011] This study addresses the issue of maintenance chemotherapy in patients with RAS wild-type, unresectable, metastatic colorectal cancer. Patients received FOLFOX and panitumumab during eight cycles of induction therapy and then were randomly badigned to two different maintenance regimens: panitumumab alone or panitumumab plus 5-FU / leucovorin infusion. They had 229 patients randomized equally in each arm. The study showed a benefit of maintenance with chemotherapy and panitumumab.

This is an area that still fascinates me. In the old days, we published a couple of articles in Lancet from the United Kingdom in which we randomized patients who responded or had a stable disease to interrupt or continue chemotherapy to progression. In those rather outdated studies, having a complete break from chemotherapy did not interfere with or reduce overall survival. And it is not surprising, it was badociated with a better quality of life.

Of course, there have been more recent studies from Italy, France and the Netherlands in which some form of non-intensified maintenance chemotherapy is badociated with the prolongation of progression. free survival This is more or less what was shown here, that instead of using panitumumab alone, if one is removing the intensity of the chemotherapy, use the infusion of 5-FU / leucovorin.

In our clinic, we tend to use capecitabine. And we tend to select patients for maintenance treatment who have a higher metastatic load or tumor burden in the presentation; that presents a relatively oligometastatic disease that, for whatever reason, is not technically ablative or operable; and those who have a good response to chemotherapy.

For the elderly, the weak and those who have suffered toxicity with chemotherapy, we would give them a break from chemotherapy and reintroduce chemotherapy into the progression of the disease.

In young, fitter patients who tolerated chemotherapy and who had a large initial burden of the disease, we would offer them a maintenance treatment. A fluoropyrimidine and an anti-EGFR inhibitor in RAS wild-type disease would seem completely reasonable. But think about the possibility of a complete cessation of chemotherapy for those who have a more indolent disease and may be less tolerant of chemotherapy.

In conclusion, enjoy the meeting of the ASCO. Choose the summaries that interest you and tell us about them in the comments section.


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