2018-19 Section 7-Neoplastic and Inflammatory Diseases of the Head and Neck eBook

Original Article

Figure 2. Flow diagram of ThyroSeq results with percentage of patients who were treated surgically and results on surgical resection. FC indicates follicular carcinoma; HR, high risk; NIFTP, noninvasive thyroid neoplasm with papillary-like nuclear features.

TABLE 2. Distribution of TBSRTC Diagnostic Categories, Surgical Follow-Up, and PPV With and Without Cases of NIFTP for ThyroSeq and Afirma GEC

TBSRTC Category

Thyroseq “HR Mutation” Cohort

AUS/FLUS

FN/SFN

SM

All Categories

No. of cases (N 5 17) Benign surgical follow-up

13

2 1 1 0 1

2 1 1 1 0

17

6 4 1 3

8 6 2 4

Malignant or NIFTP surgical follow-up

Total non-NIFTP malignancies

Total NIFTP

PPV for surgically resected nodules

40.0% 10.0% 30.0%

50.0%

50.0%

42.9% 14.3% 28.6%

PPV with NIFTP removed Absolute decrease in PPV

0.0%

NA NA

50.0%

TBSRTC Category

Afirma GEC “Suspicious” Cohort

ND

Benign

AUS/FLUS

FN/SFN

SM All Categories

No. of cases (N 5 102) Benign surgical follow-up

1 0 1 1 0

2 2 0 0 0 0

85 48 20 16

13

1 0 1 1 0 1

102

8 3 3 0

58 25 21

Malignant or NIFTP surgical follow-up

Total non-NIFTP malignancies

Total NIFTP

4

4

PPV

100

29.4% 23.5%

27.3% 27.3%

30.1% 25.3%

PPV with NIFTP removed Absolute decrease in PPV

NA NA

NA NA

NA NA

5.9%

0.0%

4.8%

Abbreviations: AUS/FLUS, atypia of undetermined significance/follicular lesion of undetermined significance; FN/SFN, follicular neoplasm/suspicious for follicu- lar neoplasm; GEC, gene expression classifier; NA, not applicable; ND, not done; NIFTP, noninvasive thyroid neoplasm with papillary-like nuclear features; PPV, positive predictive value; SM, suspicious for malignancy; TBSRTC, The Bethesda System for Reporting Thyroid Cytopathology.

NIFTP were in the indeterminate categories on cytology. When NIFTP was removed from the malignant category, there were decreases in the PPV of a positive test noted for both Afirma GEC and ThyroSeq. The PPV for a positive

HR mutation found on ThyroSeq decreased from 42.9% to 14.3%, an absolute decrease of 28.6%. The PPV of a “suspicious” Afirma GEC result decreased from 30.1% to 25.3%, an absolute decrease of 4.8% (Fig. 3).

Cancer Cytopathology

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