Over the past few decades, the rate of new thyroid cancer diagnoses has increased significantly in the US and worldwide. Much of this rising incidence is thought to be due to increased detection of papillary thyroid cancers, which are often indolent. Accordingly, disease-specific mortality has remained relatively stable and overall quite low. The approach to managing differentiated thyroid cancers, namely the papillary and follicular types, has evolved in accordance with data that most of these cases will have an excellent prognosis.
Ten years ago, patients diagnosed with thyroid cancer had a fairly predictable treatment course. Most would undergo total thyroidectomy and dissection of lymph nodes in the central neck, with many receiving radioactive iodine therapy after surgery. Today, there are multiple potential paths that an individual’s treatment may take depending on disease features and patient preferences.
In 2015, the American Thyroid Association updated its guidelines to endorse less invasive approaches to differentiated thyroid cancer. For instance, patients who have tumors <4 cm without evidence of extrathyroidal extension or clinically positive lymph nodes may be offered total thyroidectomy or unilateral thyroid lobectomy, potentially obviating the need for lifelong thyroid hormone replacement. While most papillary thyroid carcinomas are associated with positive lymph nodes in the central neck, the current literature suggests that prophylactic removal of grossly normal nodes does not improve outcomes for low-risk tumors – as such, a prophylactic lymphadenectomy is not indicated in most cases.
By decreasing the utilization of central neck lymph node dissections, patients benefit from a lower risk of hypoparathyroidism and recurrent laryngeal nerve injury. In the adjuvant setting, recommendations for radioactive iodine have become more selective as well. Current NCCN guidelines reflect a similar trend in de-escalation of treatment.
In select patients, avoidance of surgery for known or possible malignancy is now considered reasonable. Active surveillance protocols have been described for papillary thyroid carcinomas <1 cm, also called papillary thyroid microcarcinomas. Groups in Japan have reported on their experience with large cohorts of patients under active surveillance with promising results. Additionally, thyroid nodules with indeterminate cytology on fine needle aspiration biopsy can now undergo molecular testing for further risk stratification – this analysis is most useful as a “rule out” test, allowing a percentage of patients to forego diagnostic surgery.
As seen throughout the medical field, care of patients with thyroid cancer is becoming more nuanced and individualized. As surgeons, we understand that each patient comes with a unique set of values and concerns when faced with the prospect of surgery, and we tailor our approach accordingly. Ultimately, a multidisciplinary collaboration between medical and surgical teams remains critically important in ensuring appropriate care, including the prevention of overtreatment.