PMC9597005_01
(a) Baseline (9/15/16) and 3-month follow-up (12/15/2016) CT of the abdomen
demonstrate decrease in size of hepatic metastases (arrows) after three
administrations of pembrolizumab. Subsequent follow-up CT acquired at
65 months (2/10/2022) demonstrates no measurable liver disease. (b) ctDNA
monitored over time; (c) tDNA alterations and PD-L1 tested in primary tumor
tissue.. CT, computed tomography; ctDNA, circulating tumor DNA; PD-L1, programmed
death-ligand 1; tDNA, tumor DNA.
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PMC9597005_01_10.1177_17588359221122729-fig1.jpg
fig1-17588359221122729
Tumor DNA analysis by the FoundationOne platform (Foundation Medicine, Cambridge, MA, USA) measured a tumor mutation burden (TMB) of 9, two TP53 mutations and a BRCA1 mutation, among others (Figure 1(c)). The patient started palliative chemotherapy with weekly carboplatin and paclitaxel but progressed after 6 months with increased number and size of the metastases including a 3.5 cm mediastinal mass, a 3.8 cm left lower lobe (LLL) mass, and multiple liver masses measuring up to 5 cm (Figure 1A). At this time, the mediastinal mass measured 2.7 cm, the LLL mass was replaced with an area of consolidation, and the liver lesions sizes decreased with the largest now measuring 1.7 cm (Figure 1(a)). The patient remains in complete imaging remission to date, now 5-year post-treatment (Figure 1(a)). Circulating tumor mutations have been monitored using the Guardant360 platform (Guardant Health, Redwood City, CA, USA) over the last 4 years and the patient continues to present a circulating TP53 clone, although the percentage has been slowly decreasing (Figure 1(b)).