Thyroid lobectomy alone is an effective and safe treatment option for carefully selected patients with papillary thyroid cancer, according to a retrospective study by Memorial Sloan Kettering Cancer Center (MSK).
Thyroid lobectomy (TL) provided survival and recurrence outcomes comparable to the standard approach of total thyroidectomy (TT) and radioactive iodine (RAI) among patients with N1b disease with a unilateral primary tumor and low-volume lymph node metastases and no extranodal extension. The study was published on December 18, 2025, in JAMA Otolaryngology-Head & Neck Surgery. (1)
“Our study is the first in the Western hemisphere to compare survival and recurrence outcomes between total thyroidectomy and the more conservative thyroid lobectomy in this patient population,” said MSK head and neck surgeon Ian Ganly, MD, PhD, senior author of the paper. “It’s encouraging to see that patients who underwent lobectomy alone experienced similar oncologic outcomes to those who underwent total thyroidectomy and radioactive iodine, and also avoided the potential morbidity and postoperative sequelae associated with the latter.”
MSK established the first Head and Neck Cancer Surgery Service in the world 100 years ago, and continues to be at the forefront of developing advanced surgical techniques. Over the past decade, MSK thyroid experts have treated more than 6,000 patients, with a view to optimizing oncologic outcomes while minimizing the adverse effects of treatment. MSK thyroid specialists include head and neck surgeons, medical oncologists, radiation oncologists and therapists, and endocrinologists.
Trend Toward Minimizing Treatment
TT plus neck dissection is the typical approach for managing papillary thyroid cancer with lateral neck metastases in anticipation of the need for RAI. However, it is associated with an increased risk of permanent or temporary hypoparathyroidism, risk of injury to bilateral vocal cords, and permanent hypothyroidism. A large cross-sectional analysis found that TT was linked to a higher risk of respiratory complications, bleeding, hematoma, tracheostomy, and vocal cord paralysis than TL. (2)
Recently, international guidelines have moved toward a less invasive surgical approach for well-differentiated disease. A large, prospective cohort study from China involving 1,060 patients with low- to intermediate-risk differentiated thyroid cancer found that TL was superior to TT for physical and emotional function, fatigue, and appetite. (3) Also, a large study from Australia that included 1,005 patients found that patients who had TT were 1.5 times more likely to report a treatment-related adverse effect or a health-related quality-of-life (HRQOL) issue than patients who underwent TL. The study also showed that not having RAI was associated with significantly improved HRQOL. (4)
“While lobectomy is not the standard of care at MSK for patients with N1b papillary thyroid cancer, those who decline total thyroidectomy are considered for lobectomy if their primary disease is unilateral, well-defined, and if there is a low burden of lymph node disease without gross extranodal extension,” explained Dr. Ganly.
Determining whether to treat a patient with adjuvant RAI involves a discussion of related adverse effects with an endocrinologist. Short-term considerations include choosing between levothyroxine withdrawal-induced fatigue or the cost of recombinant human thyrotropin injections, isolation away from children and work, and deferring pregnancy for up to a year. (5) Common long-term adverse effects include sialadenitis, xerostomia, dysgeusia, dry eye, and epiphora. (6) RAI treatment is also associated with acute and chronic myeloid leukemia and an increased relative risk of secondary primary cancers. (7) (8) (9)
Study Design
Dr. Ganly and colleagues reviewed MSK’s prospectively maintained database of patients who had undergone surgery for thyroid cancer from 1986 to 2020 and identified those with well-differentiated papillary thyroid cancer with unilateral N1b disease. Next, they identified a group of 37 patients who had undergone TL plus unilateral lymph node dissection, with or without central neck dissection, and a propensity-matched group of 37 patients who had undergone TT and unilateral lymph node dissection, with or without central neck dissection, and received adjuvant RAI. Patients with distant metastases were excluded. (1)
All patients in the TL group had a low burden of lymph node disease on preoperative clinical examination, without gross extranodal extension, as confirmed by ultrasound or computed tomography (CT). Note that neck imaging was not part of the standard preoperative assessment at MSK during the 1980s and 1990s; therefore, imaging was not available for 26 of 37 patients in the TL group (70%). (1)
Patients were followed at six-month intervals for five years, then annually, under the MSK Adult Survivorship Program. Follow-up visits included a clinical examination, thyroid ultrasonography, and serum thyroglobulin and thyroglobulin antibody measurements. (1)
Dr. Ganly and colleagues compared overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) between the TL and TT plus RAI groups. (1)
TL (n=37) | TT + RAI (n=37) | HR | |
|---|---|---|---|
| 5-year OS | 96.9% | 96.8% | 0.20 |
| 5-year DSS | 96.7% | 100% | N/A* |
| 5-year RFS | 89.8% | 88.9% | 1.48 |
Cell 1OS = overall survival; DSS = disease-free survival; RFS = recurrence-free survival; TL = thyroid lobectomy; TT + RAI = total thyroidectomy plus radioactive iodine; HR = hazard ratio
*Calculating HR for this outcome was not feasible as there were no deaths due to thyroid cancer in the TT group.
Notably, in both groups, survival rates did not change between 5 and 10 years, and there were no local recurrences. There were two regional recurrences in the TL group and four in the TT plus RAI group. For distant recurrences, there was one case in the TL group and two cases in the TT plus RAI group. (1)
Clinical Implications
Most patients in the present study (62%) had intermediate-risk disease as defined by the American Thyroid Association. Intermediate-risk is a heterogenous group with a risk of recurrence ranging from 3% to 30%. (5) The study authors noted that subclassifying the intermediate-risk group would be beneficial for decision-making regarding RAI treatment.
A team of MSK endocrinologists recently proposed different treatment approaches for patients with low-intermediate-risk and intermediate-high-risk papillary thyroid cancer with N1b disease in their review paper published in Cancers (Basel). They defined low-intermediate-risk as having minimal extranodal extension, cancer less than 4 cm, and 5 or fewer metastatic lymph nodes between 0.3 and 3 cm. As this group has an estimated recurrence risk of 3% to 10%, adjuvant RAI may be withheld. The decision would be further supported by a postsurgical thyroglobulin level of less than 2.5 ng/mL. (5)
Intermediate-high-risk patients were defined as those with the same extent of cancer, less than 4 cm, but having more than 5 metastatic lymph nodes, extensive vascular invasion, and a thyroglobulin level greater than 2.5 ng/mL. (5) “Patients in the proposed intermediate-high risk group may benefit from adjuvant RAI, but there is no convincing data yet that RAI improves outcomes,” said Dr. Ganly.
Dr. Ganly and colleagues noted that other factors inform the RAI decision. For example, RAS-variant thyroid cancer with extensive vascular invasion retains the ability to receive RAI, whereas BRAF V600E-variant cancer does not. ( (10) (11) At MSK, patients also receive a CT scan of the neck and chest to characterize regional metastases, rule out lung metastases, and assess for retropharyngeal metastatic lymph nodes that might require RAI.
In the present study, the median number of positive nodes in both the TL and TT plus RAI groups was 5, indicating that most patients had low-volume neck disease. The study authors recommended that an individually tailored approach is essential: if RAI is not expected to reduce recurrence or DSS, then it is reasonable to consider TL for patients with unilateral intrathyroidal tumors rather than TT and RAI. If RAI is not required, the risks of TT greatly outweigh the benefits of thyroglobulin surveillance, especially given the advent of high-resolution ultrasonography and CT. (1)
“Serial levels of thyroglobulin are the most important variable rather than a single level after lobectomy,” advised Dr. Ganly. “If high-grade features are identified on molecular pathology or histology, completion thyroidectomy and adjuvant RAI are still feasible treatment options.”
“Overall, our findings highlight the importance of careful consideration of patient, pathologic, and genomic factors alongside patient preferences when developing tailored surgical plans and deciding on RAI for managing papillary thyroid cancer with lateral neck metastases,” Dr. Ganly said.
Learn more about MSK clinical trials for patients with thyroid cancer.
The study was supported by funding from the National Institutes of Health/National Cancer Institute cancer center support grant P30 CA008748 to MSK. All study authors reported no disclosures.