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Gene & Protein in Disease Utilization of genetic testing in guiding mPTC treatment

nodes, uterus, chest wall, or skeleton has been frequently family history, vascular distribution, imaging features,
reported [2-4] . We need to pay attention to these tumors, but desire to have children, and pregnancy were assessed.
there is no good way to distinguish and treat them. Active The results showed that 8% of the patients had a tumor
surveillance (AS) is recommended as a treatment of low-risk increase of ≥3 mm, while 3.8% of the patients had lymph
PTMC, as it is deemed comparable to surgical intervention. node metastasis during the 10-year AS. The incidence of
PTMCs with lymph node or distant metastasis, thyroid adverse events, such as temporary vocal cord paralysis and
extrusion, and cytological indications are all amenable to temporary or permanent parathyroidism in the immediate
the AS approach . The case investigated in this study was surgery group, was significantly higher than in the AS
[5]
a left papillary thyroid microcarcinoma with multiple right group. Therefore, the authors strongly recommend AS
cervical lymph node metastases. We also aimed to explore as the best option of clinical management for low-risk
the value of genetic testing in deciding the appropriate PTMC .
[8]
treatment, that is, surgery and AS, for PTMC.
The concept of AS in the management of malignancies
2. Case presentation has stimulated intense clinical debate. AS was regarded
as a long-term management strategy for patients, if
We present the case of a 27-year-old female patient with clinical support systems are in place, and compliance
no previous medical history who was referred to the with observation indications .The aggressiveness of
[9]
Department of Thyroid and Breast Surgery, The Fifth PTMC and the deteriorating clinical status of patients
Affiliated Hospital of Guangzhou Medical University should be considered potential challenges in AS, even if
(Guangzhou, Guangdong, China). This patient had a large thyroidectomy could help reduce the risks . Al-Qurayshi
[10]
mass in area II of her right neck. A fine-needle aspiration et al. retrospectively evaluated the risk of PTMC in
[11]
biopsy confirmed that it was a metastatic lesion of PTC. 30,180 patients with 19% of advanced features who
However, no tumor was detected in the thyroid gland underwent surgeries in the United States from 2010 to 2014.
by routine ultrasound and computed tomography (CT) The association of pathological features, epidemiologic
examinations. Multiple enlarged lymph nodes were found factors, and pathologic features with overall survival was
and distributed in the right cervical lymph node levels analyzed. The authors suggested that lobectomy should be
(Figure 1A-C). Intraoperative pathological diagnosis recommended as a diagnostic and therapeutic intervention
revealed that seven out of 23 right lymph nodes were for PTMC patients even without extrathyroid, lymph
metastatic from PTC, but no obvious cancer lesion was node, or distant metastasis to avoid further risk of delayed
seen in the thyroid gland (Figure 1D-F). After multiple [11]
postoperative sampling and micro section analysis, a treatment .
1 mm papillary carcinoma in the left thyroid gland was Choosing AS or surgery as the treatment has always
discovered (Figure 1G and H). To further investigate, been a debatable topic among the PTMC patients, mainly
a modern genetic testing approach was applied, which because there is a potential bias in the treatment selection
showed that the patient was positive for CCDC6-exon process. In this case, the patient had a 1 mm tumor in the
1-RET-exon 12 fusion (Figure 2), a driver of thyroid left thyroid with skip lymph node metastasis. However, a
cancer. Other genes tested, such as BRAFV600E, KRAS, microcarcinoma <3 mm in size may be undetectable on
NTRK1, NTRK2, NTRK3, EGFR, PIK3CA, ALK, NRAS, routine pathological examination, even if the entire thyroid
BRCA1, BRCA2, ROS1, PDGFRA, MET, HER2, NRAS, and gland is examined. Moreover, some PTCs may present with
KIT, were negative. The patient underwent post-operative intratumoral fibrosis, which is associated with increased
radioactive iodine treatment and thyroid-stimulating incidences of both extrathyroidal invasion and lymph
hormone suppression. node metastasis . In many cancers, a single microscopic
[12]
tumor cell is adequate to cause the loss of life. Therefore,
3. Discussion treatment decisions based only on tumor size, age, family
Due to the advanced ultrasound used in diagnosis, the history, or imaging of low-risk PTMC are insufficient.
incidence of PTC has been rapidly increasing in many To address this issue, genetic testing offers an approach
countries since the last decade of the 20 century . to identify whether the PTMC has a metastatic potential
[6]
th
According to the American Thyroid Association and to provide details to aid in tumor classification and
Guidelines, AS is the best clinical management for patients individualized management planning. The genetic testing
with PTMC, which shows no evidence of extrathyroidal showed that patient was positive for CCDC6-exon 1-RET-
extension . Previously, Sugitani et al. reported prospective exon 12 fusion (RET/PTC1). At present, 19 possible
[7]
clinical trials of AS for low-risk PTMC conducted at two RET/PTC rearrangements of oncogenic genes have been
Japanese centers since the 1990s . Factors such as age, reported, which are the result of the fusion of domains with
[8]

Volume 2 Issue 3 (2023) 2 https://doi.org/10.36922/gpd.0371