METHODS FOR EARLY DETECTION OF CANCER
Disclosed herein are methods, compositions, and devices for use in the early detection of cancer. The methods include preparing cell-free nucleic acid molecules from a subject for sequencing, sequencing a panel of regions in the cell-free nucleic acid molecules, and detecting one or more markers that are indicative of a cancer.
1 . A method comprising:
a) providing a sample comprising cell-free nucleic acid (cfNA) molecules from a subject, wherein the subject does not detectably exhibit a cancer;
b) capturing from the sample cfNA molecules covered by a sequencing panel, wherein the sequencing panel comprises one or more regions from each of a plurality of different genes, wherein:
i) the sequencing panel is no greater than 50,000 nucleotides;
ii) a presence of a tumor marker in any one of the different genes indicates that the subject has the cancer; and
iii) at least 80% of subjects having the cancer have a tumor marker present in at least one of the plurality of different genes; and
c) sequencing the captured cfNA molecules to a read depth sufficient to detect the tumor markers at a frequency in the sample as low as 1.0%, 0.75%, 0.5%, 0.25%, 0.1%, 0.075%, 0.05%, 0.025%, 0.01%, or 0.005%.
2 . The method of claim 1 , wherein the sample is or is derived from a blood sample of the subject.
3 . The method of claim 1 , wherein the method comprises isolating methylated cfNA prior to enriching.
4 . The method of claim 1 , wherein adaptors are ligated to the cfNA molecules prior to capturing.
5 . The method of claim 4 , wherein the adaptors comprise molecular barcodes.
6 . The method of claim 5 , wherein the ligation conditions comprise the use of over a 10×, over 20×, over 40×, over 60×, or over 80× molar excess of adaptors.
7 . The method of claim 1 , wherein the capturing is performed using nonspecific oligonucleotide probes.
8 . The method of claim 7 , wherein the capturing comprises a differential tiling of the oligonucleotide probes.
9 . The method of claim 1 , wherein the captured cfNA is amplified prior to sequencing.
10 . The method of claim 1 , wherein the sequencing is massively parallel sequencing that sequences at least 10 million polynucleotide molecules.
11 . The method of claim 1 , wherein the sequencing generates sequencing data comprises at least 1 billion, 1.1 billion, 1.2 billion, 1.5 billion, 2 billion, 2.5 billion, 3 billion, 3.5 billion, 4 billion, 4.5 billion, 5 billion, 5.5 billion, 6 billion, 6.5 billion, 7 billion, 8 billion, 9 billion or 10 billion base pairs.
12 . The method of claim 1 , wherein a read budget is selected that identifies the total number of base reads to be allocated to the sample, wherein the sample comprises a predetermined amount of DNA.
13 . The method of claim 1 , wherein the sequencing is performed at a depth of at least 50,000 reads per base, at least 100,000 reads per base, or at least 120,000 reads per base.
14 . The method of claim 13 , wherein the reads per base represent at least 5,000 original cfDNA molecules in the sample.
15 . The method of claim 1 , wherein the subject has previously received surgical treatment, radiation treatment, chemotherapy, targeted cancer therapeutics or a cancer immunotherapy.
16 . The method of claim 1 , wherein sequence reads from the sequencing data are mapped to a reference sequence.
17 . The method of claim 16 , wherein the detecting one or more genetic variants in the cfNA comprises determining a consensus sequence from sequence reads obtained from the sequence data to reduce errors from amplification or sequencing.
18 . The method of claim 17 , wherein the consensus sequence is performed on a molecule-by-molecule basis or a base-by-base basis.
19 . The method of claim 16 , wherein molecular barcodes are used to group the sequencing reads into families derived from original individual cfNA molecules, wherein the consensus sequence is generated for the family either on a molecule-by-molecule basis or a base-by-base basis.
20 . The method of claim 1 , wherein a frequency of nucleotides in the sample is determined by comparing it to a frequency of germline DNA from the subject.