Figure 1 from Monitoring Circulating Tumor DNA During Surgical Treatment in Patients with Gastrointestinal Stromal Tumors

Experimental overview and primary tumor mutations. A, Consort diagram of the eligible patient cohort and study enrollment. The cohort consisted of all patients treated at the Deparment of Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden, between November 2016 and March 2019. Forty-three of the 91 initially included patients were excluded. Of the excluded patients, nine patients revealed other diagnoses than GIST by pathology analysis, five patients displayed neither KIT nor PDGFRA mutations (wild-type) in tumor biopsy, three patients had no mutation analysis performed on the tumor material and 26 patients were enrolled after surgery and hence excluded. Thirty-two of 48 patients that were included before surgery were finally analyzed for the presence of ctDNA. Of the 16 additionally excluded patients, five patients were excluded, because sampling was not possible during surgery, samples from two patients were used in workflow optimization and nine patients were excluded as their tumor-specific mutations were not targeted by the developed assays. B, Five SiMSen-Seq assays were used to assess each patient, including one tumor-specific assay targeting the mutation identified in the tumor biopsy combined with four resistance assays. Blood samples were collected during routine visit before and after surgery. At surgery, samples were collected at start of surgery, during mobilization of the tumor and at closure. Extracted cfDNA was analyzed by SiMSen-Seq. Several quality controls were used to monitor the experimental performance. C, Assay overview and detected mutations in tumor biopsy. The length and exon position of each assay are shown. All types of mutations and their position are indicated for all 32 patients. SNV, single-nucleotide variant; indel, insertion or deletion mutation.