Summary

Surgery

• Lobectomy for one sided, ≤ 4.0 cm cancers.
• Total thyroidectomy for ≥ 4.0 cm or bilateral cancers, extrathyroidal extension (invading nearby structures), or lymph node spread (regional metastasis).
• Central and lateral neck dissections for proven spread to lymph nodes.
  • Either by biopsy (FNA) prior to surgery or determined on frozen biopsy during surgery.
  • Spreads first to lymph nodes in the central neck, then the lateral neck.
    • If cancer is discovered in a lateral neck lymph node, central neck dissection also be performed as it is assumed to have spread there first.
• Prophylactic central neck dissection (no proven spread to lymph nodes).
  • If gross extrathyroidal extension into strap muscles, trachea, or recurrent laryngeal nerve.
• Unresectable cancer
  • If at any time cancer in the neck is considered unresectable (or resectable but with unacceptable co-morbidities), TKI (tyrosine kinase inhibitors) and/or targeted molecular therapy may be able to shrink the cancer to make it resectable.

For all types of thyroid cancer, surgical outcomes / cure rates are the highest and complication rates are the lowest when surgery is performed by a high-volume surgeon (> 50 thyroid cancer surgeries per year).

To read more about Thyroid and Neck Dissection surgeries including what to expect, as well as details regarding recovery and risks:

• Hemithyroidectomy.
• Total Thyroidectomy.
• Central Neck Dissection.
• Lateral Neck Dissection.

• AJCC Tumor Staging System using pathology features and patient age.
  • 10-year survival rates can be estimated based on stage.
• American Thyroid Association Risk Stratification System.
  • Uses pathology features to estimate initial risk for cancer recurrence.

TSH Suppression

• Based on risk for recurrence.
• Achieved by giving higher doses of thyroid hormone replacement medication (e.g. levothyroxine, Synthroid, etc.).

Radioactive Iodine (RAI)

• Reserved for cancers with intermediate and high risk for recurrence.
  Determined by pathology report and thyroglobulin (Tg) levels measured in the blood 6 weeks following surgery.
• Goal is to kill of any remaining normal thyroid cells to make Tg measurements more sensitive (remnant ablation) with lower doses (~30 mCi) or to kill of suspected residual cancer cells (adjuvant therapy) with higher doses (~ 150 mCi).

Ultrasound of the neck, including the lateral neck compartments.

• Concerning lesions should be biopsied.
• If there is high suspicion for recurrence based on elevated Tg levels, but no disease is seen on ultrasound, consider CT Neck / Chest with contrast, Iodine Whole Body Scan, or PET CT.

Thyroglobulin (Tg) and thyroglobulin antibody (Tg Ab) levels (blood test).

• Rise in Tg levels would suggest cancer has recurred, even if not visible yet on ultrasound.

TSH levels (blood test).

• TSH must be appropriately suppressed according to level risk for recurrence.
• If TSH levels are not appropriately suppressed, Tg levels may be falsely elevated.

Surveillance is initially performed every 3 – 6 months based on initial risk for recurrence.

• Can eventually decrease frequency to every 12 months if no / low concern for cancer recurrence based on dynamic risk assessment.

Surveillance is performed for total of 5 years.

• If no objective evidence of recurrence by 5 years, the patient is considered cured.
• If concern for recurrence persists at 5 years, surveillance should be continued indefinitely.

Treatment for recurrent cancer in the neck or distant spread of cancer.

• Should be treated surgically if possible.
• Consider RAI if still susceptible to iodine (i.e., iodine avid).
• Targeted external beam radiation.
  • Particularly if in a single distant site, especially bone.
• Targeted systemic therapy.
  • Dependent on DNA alteration driving the cancer and existence of drugs specifically targeting this.

If at any time the cancer is considered not curable, the patient / family / treatment team should collectively consider:

• Palliate tracheotomy to prevent future airway compromise (cancer directly invading the larynx and/or trachea effecting the patient’s ability to breathe).
• Feeding tube placement to allow for adequate nutrition and administration of medications if the cancer invades the pharynx or esophagus.
• Establish goals of treatment and advance directives / end of life care plan.