Page 19 - Delaware Medical Journal - December 2016
P. 19
SCIENTIFIC ARTICLE
sensitivity and 94 percent and 95 percent
10 The being multi-center, prospective and the use of blinded pathologists. Validation for ThyroSeq is single center, combined retrospective/prospective and with unblinded pathologists2,3 (Table 2). The mutation, the only mutation in this study found to have clinical utility.
Patients with mutations were found in
percent) patients with a mutation had Table 1). RAS mutation is the most common mutation for indeterminate thyroid nodules,7 10 percent, respectively of indeterminate thyroid nodules.7 In this study RAS
was found in four of nine (44 percent)
of indeterminate thyroid nodules. The
It has been reported that not knowing the mutation for indeterminate cytology who received initial lobectomy were 2.5 times more likely to require 2-stage surgery for 11 This is the basis for supported clinical testing for the physician who recommends total thyroidectomy for differentiated thyroid cancer.
There are several factors that currently
predict malignancy in two of two (100
percent) indeterminate thyroid nodules
in this study. However the need for intrathyroidal malignancies without clinically evident lymph node metastases
to undergo total thyroidectomy is
unclear, and not mandated by current guidelines.7 Recommendation 35 of the 2015 ATA guidelines7 states patients without extrathyroidal extension, and without clinical evidence of any lymph
surgical procedure can be either a
bilateral procedure (near-total or total thyroidectomy) or a unilateral procedure for the practice that recommends total thyroidectomy for differentiated thyroid if the treating physician recommends lobectomy.
Another extrinsic factor that limits the
12 follicular thyroid neoplasm with papillary 13 has limited malignant potential. Re-
in” molecular alteration testing. Bayes theorem (Figure 1) in the calculation of PPV depends not only on sensitivity prevalence. As prevalence decreases, PPV decreases. Even for surgeons
who recommend total thyroidectomy for differentiated thyroid cancer, they should consider diagnostic lobectomy for patients with nodules that have a
Conversely, these are favorable extrinsic
increases.
An intrinsic potential limiting factor
for the RAS mutation.14 Although this
is supported by other workers where
RAS is associated with a 93 percent PPV for malignancy,15 others have reported RAS positive tumors to be positive for malignancy in only 47 percent, and when positive for malignancy associated with Only two mutation were malignant in this series and
7 as it was in this series.
the tumoral capsule, and greater tumor diameter. positive may lead the surgeon to perform therapeutic total thyroidectomy rather that diagnostic lobectomy thus reducing the incidence of completion thyroidectomy. 7 alone should determine the extent of surgery.
High-risk history, physical and
appropriate selection of patients with
In this practice setting, more than half
of the ThryoSeq results are without a mutation, and these patients are followed clinically and with ultrasound in lieu of diagnostic surgery. This report is also in
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