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Importance: Novel sensitive methods for detection and monitoring of residual disease can improve postoperative risk stratification with implications for patient selection for adjuvant chemotherapy (ACT), ACT duration, intensity of radiologic surveillance, and, ultimately, outcome for patients with colorectal cancer (CRC)., Objective: To investigate the association of circulating tumor DNA (ctDNA) with recurrence using longitudinal data from ultradeep sequencing of plasma cell-free DNA in patients with CRC before and after surgery, during and after ACT, and during surveillance., Design, Setting, and Participants: In this prospective, multicenter cohort study, ctDNA was quantified in the preoperative and postoperative settings of stages I to III CRC by personalized multiplex, polymerase chain reaction-based, next-generation sequencing. The study enrolled 130 patients at the surgical departments of Aarhus University Hospital, Randers Hospital, and Herning Hospital in Denmark from May 1, 2014, to January 31, 2017. Plasma samples (n = 829) were collected before surgery, postoperatively at day 30, and every third month for up to 3 years., Main Outcomes and Measures: Outcomes were ctDNA measurement, clinical recurrence, and recurrence-free survival., Results: A total of 130 patients with stages I to III CRC (mean [SD] age, 67.9 [10.1] years; 74 [56.9%] male) were enrolled in the study; 5 patients discontinued participation, leaving 125 patients for analysis. Preoperatively, ctDNA was detectable in 108 of 122 patients (88.5%). After definitive treatment, longitudinal ctDNA analysis identified 14 of 16 relapses (87.5%). At postoperative day 30, ctDNA-positive patients were 7 times more likely to relapse than ctDNA-negative patients (hazard ratio [HR], 7.2; 95% CI, 2.7-19.0; P < .001). Similarly, shortly after ACT ctDNA-positive patients were 17 times (HR, 17.5; 95% CI, 5.4-56.5; P < .001) more likely to relapse. All 7 patients who were ctDNA positive after ACT experienced relapse. Monitoring during and after ACT indicated that 3 of the 10 ctDNA-positive patients (30.0%) were cleared by ACT. During surveillance after definitive therapy, ctDNA-positive patients were more than 40 times more likely to experience disease recurrence than ctDNA-negative patients (HR, 43.5; 95% CI, 9.8-193.5 P < .001). In all multivariate analyses, ctDNA status was independently associated with relapse after adjusting for known clinicopathologic risk factors. Serial ctDNA analyses revealed disease recurrence up to 16.5 months ahead of standard-of-care radiologic imaging (mean, 8.7 months; range, 0.8-16.5 months). Actionable mutations were identified in 81.8% of the ctDNA-positive relapse samples., Conclusions and Relevance: Circulating tumor DNA analysis can potentially change the postoperative management of CRC by enabling risk stratification, ACT monitoring, and early relapse detection.

Hairy cell leukemia (HCL) is a chronic B-lymphocyte leukemia. Due to the proliferative inertia of the malignant cells, HCL-derived cell lines are an important tool for studies on this disease. We have elaborated the karyotypes of three HCL-derived cell lines, ESKOL, JOK-1, and Hair-M, by combining a range of molecular cytogenetic techniques, including multiplex (multicolor) fluorescence in situ hybridization (M-FISH), comparative genomic hybridization (CGH), conventional FISH, primed in situ labeling (PRINS), and dideoxyPRINS. We found ESKOL to be monoclonal with a single chromosome aberration, der(7)t(3;7)(q26.3;q31). JOK-1 also appeared to be monoclonal, having the karyotype 48,XY,der(4) t(1;4)(1pter-->p32::4qter-->pter), der(6)(6qter-->p22::q12--> qter), +der(7)t(7;11)(7pter-->q21::11p15-->pter),der(8)t(5;8;12) (5pter-->p14::12p11.2-->p12::8q12-->q21::8?cen-->-->24 .?2), der(14)t(8;14)(8qter-->q24.?2::14q32.3-->pter),+20. These karyotypes differ from the original descriptions of ESKOL and JOK-1. The Hair-M cells analyzed by us were found to be peritetraploid with numerous chromosomal rearrangements. The cell line was also found to be multiclonal. On this basis, we do not regard the Hair-M cell line to be suitable for HCL studies.

Loss of a chromosome 7 is associated with a poor prognosis in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Some studies have shown higher frequencies of monosomy 7 (-7) in dividing than nondividing myeloid cells, which might indicate that -7 confers a proliferative advantage on the host cell. As other groups have not been able to confirm this, we compared the -7 frequencies in bone marrow metaphases as studied with conventional cytogenetics and in interphase cells using primed in situ (PRINS) labeling. We found significantly higher -7 frequencies in metaphase than in interphase cells irrespective of diagnosis and presence or absence of additional chromosome aberrations. Further, we found a significant correlation between the -7 percentages in resting and dividing cells. Finally, as our material showed a clear male preponderance, Mitelman's Catalog of Chromosome Aberrations in Cancer was searched for -7. Of 815 cases with AML or MDS, 491 (60.3%) were found to be men. To our knowledge, this is the first observation of a clear deviation from the 1:1 sex ratio in -7 patients.