Thyroid cancer: assessment and management

Explain to people with suspected thyroid cancer:

• that not all lumps, nodules or swellings in the thyroid are cancer

• what the diagnostic pathway involves and what tests they may need.

Offer people with suspected or confirmed thyroid cancer, and their family and carers if appropriate, information on what hemithyroidectomy or total thyroidectomy involves. Explain the benefits and risks of treatment, including long-term implications such as:

• the effects of having part or all of your thyroid removed

• the potential for and possible consequences of:

  • hypothyroidism and the subsequent need for lifelong thyroid hormone replacement

  • the need for treatment for low parathyroid hormone

  • voice change and swallowing disorders.

Do not refer to thyroid cancer as a 'good cancer' because many people do not find this reassuring and it can cause them to feel that their diagnosis is unimportant.

Consider further appointments if they will benefit a person's psychological wellbeing, even if they are not indicated for physical reasons.

At follow up, give people with thyroid cancer, and their family and carers if appropriate, information on:

• follow up and how it is likely to be done

• what thyroglobulin is, how it is measured and why

• lifelong thyroid hormone replacement

• lifelong monitoring of thyroid function

• when to seek advice from a healthcare professional, who that healthcare professional should be and how to contact them.

Offer people with suspected or confirmed thyroid cancer, and their family and carers if appropriate, the following information on the benefits, and short- and long-term risks of, radioactive iodine (RAI):

• the aim of RAI is to destroy any residual thyroid tissue, including tissue that may be malignant, and to allow for effective monitoring for recurrence by a blood test

• precautions may be needed when taking RAI which may temporarily affect conception, pregnancy, breastfeeding and fertility

• although uncommon, there is the potential for dry mouth and salivary gland inflammation, both of which are temporary in most people

• there is a potential but very low risk of RAI causing new primary second cancers.

Do not use calcitonin testing to assess thyroid nodules unless there is a reason to suspect medullary thyroid cancer (MTC), such as a family history or a nodule with an appearance on ultrasound that suggests MTC.

Do not routinely measure thyroid peroxidase antibody (TPO).

Consider measuring TPO when interpreting indeterminate cytopathology.

Offer greyscale ultrasound with an established system for grading ultrasound appearance as the initial diagnostic test when investigating thyroid nodules for malignancy.

Use the initial FNAC results to determine further management and sampling options, as shown in table 1.

Do not routinely use radioisotope scans for the initial diagnosis of thyroid cancer.

Do not routinely use cross-sectional imaging (CT or MRI) for people with T1 or T2 disease and no other indications.

Consider CT of neck and chest, or MRI of neck and CT of chest for people with T3 or T4 thyroid cancer or any N1 or M1 thyroid cancer or other clinical suspicion of metastases.

Offer hemithyroidectomy or total thyroidectomy to people with:

• differentiated thyroid tumours larger than 1 cm or

• multifocal disease (T1a [m] to T2N0M0).

Offer total thyroidectomy to people who have:

• a T3 or T4 stage primary tumour

• regional lymph node involvement (N1)

• adverse pathological features

• distant metastatic disease (M1).

Offer completion thyroidectomy to people who have had a hemithyroidectomy if it is indicated on review of the histological features of the initial specimen.

Consider hemithyroidectomy or active surveillance for people with a solitary microcarcinoma (T1a) without evidence of nodal involvement.

Offer a compartment-orientated lateral neck dissection for people with structural nodal disease in the lateral neck.

Consider a preventive ipsilateral central neck dissection when doing the compartment-orientated lateral neck dissection for people with structural nodal disease in the lateral neck.

Offer a compartment-orientated central neck dissection for people with structural nodal disease in the central neck.

Do not offer preventive central or lateral neck dissection (except in the circumstances in recommendation 1.3.7).

Consider delaying surgery until after pregnancy, taking into account the:

• risk of delaying surgery

• risk to the pregnancy

• rate of disease progression.

The obstetrician, surgeon and endocrinologist should discuss the factors in recommendation 1.3.9 and jointly decide with the person whether to delay surgery.

When surgery cannot be delayed until after pregnancy, do it during the second trimester, if possible.

Offer thyrotropin alfa for pretherapeutic stimulation for people with thyroid cancer (including those with distant metastases; see recommendation 1.3.13) who are having RAI ablation.

In December 2022 this use of thyrotropin alfa as a treatment for thyroid cancer for people with distant metastases was off-label. See NICE's information on prescribing medicines.

Use thyrotropin alfa with caution for people with thyroid cancer who have brain or spinal metastases, because there is a risk of clinically significant tumour flare.

Offer RAI to people who have had a total or completion thyroidectomy based on the criteria in the recommendations on offering total thyroidectomy in the section on surgery and active surveillance for primary tumours.

Do not offer RAI to people with T1a or T1b tumours, including those with multifocal disease, unless there are adverse features, regional lymph node involvement, or evidence of other metastatic disease.

Consider RAI for people with T2 disease who have had a total or completion thyroidectomy, but whose cancer does not show any of the features in the recommendations on offering total thyroidectomy in the section on surgery and active surveillance for primary tumours.

Consider RAI with an activity for initial ablation of 3.7 GBq for people:

• with high-risk features, such as T4, N1b or M1 disease or aggressive subtypes or

• who should avoid multiple ablations because they have one or more of the following characteristics:

  • significant comorbidities such as cardiovascular disease

  • mobility issues

  • complex social concerns.

Offer RAI with an activity for initial ablation of 1.1 GBq for people who are not having 3.7 GBq.

Consider external beam radiotherapy (EBRT) if there is:

• macroscopic disease after surgery or

• local disease that is unlikely to be controlled with RAI.

Consider EBRT for symptom control for people having palliative care.

Do not offer thyroid-stimulating hormone (TSH) suppression to people who:

• do not meet the threshold for RAI (see the section on RAI for initial ablation)

• have significant comorbidities that mean low TSH levels should be avoided.

Offer thyroid hormone at doses that will suppress TSH to below 0.1 mIU/litre to people who have had total or completion thyroidectomy and RAI.

Continue TSH suppression until follow-up review at 9 to 12 months after initial treatment has been completed.

Use dynamic risk stratification to determine further management at 9 to 12 months after completion of initial RAI ablation, as follows:

• Reduce TSH suppression to achieve a TSH level of between 0.3 mIU/litre and 2.0 mIU/litre, and continue this for life for people who have an excellent response to treatment.

• Continue TSH suppression to achieve a TSH level of between 0.1 mIU/litre and 0.5 mIU/litre for people who have an intermediate response to initial treatment.

Continue to suppress TSH to less than 0.1 mIU/litre for people who have biochemical or structural evidence of persistent or recurrent disease.

Offer a review to people who have had ongoing TSH suppression for more than 10 years. Decide whether the TSH suppression can be reduced after an individualised assessment of risks and benefits, and explain that:

• lifelong suppression is not necessary unless they have high-risk or metastatic disease

• reducing TSH suppression may lower the risk of developing bone and cardiac problems.

When measuring thyroglobulin and thyroglobulin antibodies, take into account that:

• the presence of thyroglobulin antibodies, above the laboratory threshold, can interfere with the measurement of thyroglobulin levels

• detectable thyroglobulin levels for people without thyroglobulin antibodies suggest the presence of residual thyroid tissue, or residual or recurrent thyroid cancer.

Offer thyroglobulin measurement alongside measurement of thyroglobulin antibodies for people with differentiated thyroid cancer who have had total or completion thyroidectomy and RAI. Measure at:

• 3- to 6-month intervals in the first 2 years after RAI ablation and

• 6- to 12-month intervals thereafter.

Consider further investigations if a person has had total thyroidectomy and RAI, and:

• has detectable thyroglobulin levels without thyroglobulin antibodies

• investigations have not shown recurrent or residual cancer in the presence of detectable thyroglobulin without thyroglobulin antibodies, and now the thyroglobulin levels without thyroglobulin antibodies are rising.

Consider further investigations if a person has:

• had a total thyroidectomy without RAI and

• rising thyroglobulin levels without thyroglobulin antibodies.

Do not routinely measure thyroglobulin levels for people who have not had total or completion thyroidectomy.

Consider further investigations:

• when thyroglobulin antibodies are first detected above the laboratory threshold or

• at any point if the levels of thyroglobulin or thyroglobulin antibodies are rising.

Consider either a stimulated thyroglobulin test or highly sensitive thyroglobulin test if thyroglobulin is undetectable on a standard assay for people who have:

• had a total or completion thyroidectomy and RAI and

• no evidence of structural persistent disease.

Consider the following if using a stimulated thyroglobulin test:

• less frequent follow-up, when appropriate, and more relaxed TSH suppression if stimulated thyroglobulin is below 1 microgram/litre (low risk)

• continuing TSH suppression if stimulated thyroglobulin is between 1  and 10 microgram/litre (indeterminate risk)

• further investigations and treatment if stimulated thyroglobulin is 10 microgram/litre or more and there is no resectable disease.

Consider the following if using a highly sensitive assay that can detect thyroglobulin levels lower than 0.2 microgram/litre:

• less frequent follow-up, when appropriate, and more relaxed TSH suppression if the thyroglobulin level is lower than 0.2 microgram/litre

• stimulated thyroglobulin, which can be helpful in separating people into lower- and higher-risk groups if the thyroglobulin level is between 0.2  and 1 microgram/litre.

Use caution when interpreting results in the presence of thyroglobulin antibodies because they may cause false-positive or negative findings.