Table 1.
Study and population characteristics
| Study | Participant selection and disease prevalence a | Participant characteristics | Reference standard | Microdissection | MSI Panel | MSI thresholds | ||
|---|---|---|---|---|---|---|---|---|
| Population-based and age-limited single-gate studies | ||||||||
| Barnetson, 2006 | Diagnosed <55yrs of age, consecutive recruitment Disease prevalence 8.5% (95% CI 5.8 to 11.9) |
Number: | For all participants: Germ-line DNA obtained from blood leukocytes analysed for MLH1, MSH2, and MSH6 mutations. dHPLC analysis was used for MSH2 and MLH1. Variants noted on chromatography were then sequenced. Mutations were confirmed by re-amplification of an independent sample of DNA and resequencing in both directions. MLH1 and MSH2 were assessed for deletions by MLPA, with products separated on a genetic analyser. |
10μm tumour sections; microdissection performed on purified tumour DNA, and control DNA from blood or normal tissue in the section | Bethesda/NCI panel | MSI-H: >1 marker MSI-L: 1 marker MSS: 0 markers |
||
| Recruited | 1259 | |||||||
| Receiving RS | 870 | |||||||
| Receiving MSI | 352 | |||||||
| Gender: | ||||||||
| Male | 53.1% | |||||||
| Female | 46.9% | |||||||
| Age (in years): | ||||||||
| Non-carrier | 48.2 (±6.0) | |||||||
| Carrier | 42.7 (±7.7) | |||||||
| MLH1 | 38.5 (±8.4) | |||||||
| MSH2 | 43.8 (±6.1) | |||||||
| MSH6 | 49.0 (±3.9) | |||||||
| Clinical criteria: | ||||||||
| AMS II | 4.0% | |||||||
| RBG | 64.0% | |||||||
| Poynter, 2008b | Recruitment through population-based cancer registries (population-based sample), selection process unclearc
Disease prevalence 9.2% (95% CI 7.1 to 11.8) |
Number: | For all MSI-H or MSI-L probands and in a random sample of 300 MSS population-based probands: Mutations in MSH2 and MLH1 were detected using a combined approach of dHPLC/direct sequencing and MLPA. Direct sequencing was used to detect MSH6 mutations in cases with absent IHC staining of MSH6. | NR | BAT25, BAT26, D5S346, D17S250, BAT40, MYCL, ACTC, Dl 8S55, D1OS197, BAT34C4 |
MSI-H: ≥30% MSI-L: >0% and <30% MSS: 0% |
||
| Recruited | 1061 | |||||||
| Receiving RS | 726 | |||||||
| Receiving MSI | 1061 | |||||||
| Gender: NCR | ||||||||
| Age (in years): NCR | ||||||||
| Clinical criteria: NCR | ||||||||
| Southey, 2005 | Diagnosed <45yrs of age, random recruitment Disease prevalence 30.5% (95% CI 19.2 to 43.9) |
Number: | For all MSI-H or MSI-L probands, those that lacked expression of at least one MMR protein and a random sample of 23 patients selected from those who had tumours that were MS stable and did not lack expression of any MMR protein: MLH1, MSH2, MSH6, and PMS2 genes were screened for germline mutations using sequencing approaches or dHPLC. Confirmation of putative mutations was sought using an independent polymerase chain reaction for direct automated sequencing. MLPA was used to detect large genomic alterations in MLH1 and MSH2 on samples from 10 patients who had tumours lacking at least one MMR protein expression and for which no previous mutation had been identified by sequencing. | 5μm tumour sections; microdissection performed on invasive tumour cells from paraffin-embedded archival tumour tissue stained with 1% methyl-green, and normal cells from colonic or lymph node tissue/DNA extracted from peripheral blood lymphocytes | BAT25, BAT26, D2S123, D5S346, D17S250, BAT40, MYB, TGFRII, IGFIIR, BAX |
MSI-H: >5 markers MSI-L: 2-5 markers MSS: <2 markers |
||
| Recruited | 131 | |||||||
| Receiving RS | 59 | |||||||
| Receiving MSI | 105 | |||||||
| Gender: | ||||||||
| Male | 62.7% | |||||||
| Female | 37.3% | |||||||
| Age (in years): | ||||||||
| 37.1 (range 24 to 42) | ||||||||
| Clinical criteria: | ||||||||
| AMS II | 9.2% | |||||||
| RGB | NR | |||||||
| High-risk, single-gate studies | ||||||||
| Caldes, 2004 | HNPCC families selected through a clinic for familial cancer, selection process unclear Disease prevalence 58.6% (95% CI 44.9 to 71.4) |
Number: | For all participants: Genomic DNA was isolated from peripheral blood lymphocytes was analysed for MLH1, MSH2 and MSH6. DNA was amplified using PCR and all amplicons were subjected to DGGE or cycle sequencing. The MSI-H cases that were negative for mutations were analysed for genomic deletions in MLH1 and MSH2 by Southern Blotting. | 10μm tumour sections; microdissection performed on H&E stained slides with demarked areas containing cancer cells, and corresponding areas on unmarked slides | Bethesda/NCI panel | MSI-H: >1 marker, or 1 marker if BAT26 MSI-L: Not used MSS: 0 markers |
||
| Recruited | 58 | |||||||
| Receiving RS | 58 | |||||||
| Receiving MSI | 58 | |||||||
| Gender: NR | ||||||||
| Age (in years): NR | ||||||||
| Clinical criteria: NR | ||||||||
| Mueller, 2009 | ‘Suspected Lynch syndrome’ participants who met Amsterdam criteria, modified Amsterdam criteria, were ‘HNPCC-like’ or met Bethesda criteria, selection process unclear Disease prevalence 58.3% (95% CI 43.2 to 72.4) |
Number: | For all participants: Sequencing and MLPA. Limited details provided. | NR | 5 and 10 panel markers, no further details provided | NR | ||
| Recruited | 48 | |||||||
| Receiving RS | 48 | |||||||
| Receiving MSI | 48 | |||||||
| Gender: NR | ||||||||
| Age (in years): NR | ||||||||
| Clinical criteria: NR | ||||||||
| Overbeek, 2007 | Families history that fulfilled one of the following criteria: 1) Amsterdam II criteria 2) Bethesda guidelines 3) a history very close to the Bethesda guidelines, selection process unclear Disease prevalence NC |
Number: | For all participants: Mutation analysis of MLH1, PMS2, MSH2, and MSH6 was performed in DNA from peripheral blood lymphocytes by a combination of either single-strand conformation polymorphism analysis or DGGE and direct sequence analysis. For the detection of large deletions and duplications in MLH1, MSH2, MSH6, and PMS2, MLPA was used. All deletions and duplications were confirmed by Southern blot analysis or with a specific PCR. |
NR | BAT25, BAT26, D2S123, D5S346, D17S250 (BAT40 was also added to the standard set of markers but it is unclear for which participants) | Tumours categorised as positive (>2 Bethesda markers) or negative | ||
| Recruited | NR | |||||||
| Receiving RS | NR | |||||||
| Receiving MSI | NR | |||||||
| Gender: NR | ||||||||
| Age (in years): 40.7 (range 29 to 51) | ||||||||
| Clinical criteria: NR | ||||||||
| Poynter, 2008b | Recruitment through high-risk clinics (clinic-based sample), selection process unclearc
Disease prevalence 30.9% (95% CI 23.7 to 38.9) |
Number: | For all participants: Mutations in MSH2 and MLH1 were detected using a combined approach of dHPLC/direct sequencing and MLPA. Direct sequencing was used to detect MSH6 mutations in cases with absent IHC staining of MSH6. |
NR | BAT25, BAT26, D5S346, D17S250, BAT40, MYCL, ACTC, Dl 8S55, D1OS197, BAT34C4 | MSI-H: ≥30% MSI-L: >0% and <30% MSS: 0% |
||
| Recruited | 172 | |||||||
| Receiving RS | 152 | |||||||
| Receiving MSI | 172 | |||||||
| Gender: NR | ||||||||
| Age (in years): NR | ||||||||
| Clinical criteria: NR | ||||||||
| Shia, 2005 | Family history that fulfilled one of the following criteria: I ) Amsterdam I or II criteria 2) a set of relaxed AC three or more colorectal cancers among the first and second-degree relatives of a family that we referred to as ''HNPCC-like,'' and 3) Bethesda criteria, selection process unclear Disease prevalence 49.2 (95% CI 36.1 to 62.3) |
Number: | For all participants: Each of the exons of MLH1, MSH2 and MSH6 was amplified by PCR, and heteroduplex analyses were performed using dHPLC. DNA fragments that displayed an abnormal chromatogram were sequenced directly. Cases with tumours that exhibited MSI but in which a point mutation was not detected were analysed for large deletions in MLH1 and MSH2 using a procedure based on the multiplex PCR of short fluorescent fragments. |
Microdissection performed on DNA from paraffin-embedded tissue blocks. No further details reported | BAT25, BAT26, D2S123, D17S250, BAT40, PAX6, MYCL1 | Tumours categorised as positive (≥30%) or negative | ||
| Recruited | 83 | |||||||
| Receiving RS | 83 | |||||||
| Receiving MSI | Unclear d | |||||||
| Gender: | ||||||||
| Male | 43.6% | |||||||
| Female | 56.3% | |||||||
| Age (in years): | ||||||||
| 50 (range 23 to 78) | ||||||||
| Clinical criteria: | ||||||||
| AMS II | 38.2% | |||||||
| RBG | 8.2% | |||||||
| Reference standard positive study | ||||||||
| Hendriks, 2003 | Germline mutation in MLH1, MSH2 or MSH6, selection process unclear Disease prevalence 84.8% (95% CI 68.1 to 94.9)e |
Number: | For all participants: DGGE or Southern blotting. Limited details provided | Microdissection not specifically reported, paired tumour and normal tissue DNA samples were used | BAT25, BAT26, D2S123, D5S346, D17S250, BAT40, MSH3 and MSH6 | MSI-H: >1 Bethesda markers MSI-L: 1 Bethesda marker MSS: 0 Bethesda markers |
||
| Recruited | 45 | |||||||
| Receiving RS | 45 | |||||||
| Receiving MSI | 33 | |||||||
| Gender: | ||||||||
| Male | 35.6% | |||||||
| Female | 40.0% | |||||||
| Age (in years): | ||||||||
| MLH1 48 (range 29 to 90) | ||||||||
| MSH2 40 (range 23 to 61) | ||||||||
| MSH6 62 (range 26 to 84) | ||||||||
| Clinical criteria: NR | ||||||||
NC not calculable, total number of participants with CRC not reported, NR Not reported, NCR Not clearly reported; aDisease prevalence calculations were based on participants who received both the index test and the reference standard and for whom data were reported. The disease prevalence may, therefore not be an accurate representation of the prevalence in the recruited population, and this is more likely in studies that did not aim to assess the reference standard in all recruited participants; for example, two study samples (the population based sample in Poynter, 2008, and Southey, 2005) did not perform the reference standard in all participants with an MSS result. bPoynter (2008) reports data from two distinct samples, a population-based sample and a high-risk sample; cAlthough Poynter (2008) reports that ‘some centres recruited all incident cases of CRC while others over sampled cases with a family history or early age of onset’ it is not clear whether this applies to the high-risk sample alone or in part to the high-risk sample and in part to the population based sample; d MSI data are available for 61 participants but it is unclear how many received the test; eAlthough only reference standard positives were recruited, this included those with an unclassified variant, so when those unclassified variants were considered to be reference standard negatives disease prevalence is 84.8%