Incidences of Unfavorable Events in the Management of Low-Risk Papillary Microcarcinoma of the Thyroid by Active Surveillance Versus Immediate Surgery

Abstract

Background: The incidence of papillary microcarcinoma (PMC) of the thyroid is rapidly increasing globally, making the management of PMC an important clinical issue. Excellent oncological outcomes of active surveillance for low-risk PMC have been reported previously. Here, unfavorable events following active surveillance and surgical treatment for PMC were studied.Methods: From February 2005 to August 2013, 2153 patients were diagnosed with low-risk PMC. Of these, 1179 patients chose active surveillance and 974 patients chose immediate surgery. The oncological outcomes and the incidences of unfavorable events of these groups were analyzed.Results: In the active surveillance group, 94 patients underwent surgery for various reasons; tumor enlargement and the appearance of novel lymph node metastases were the reasons in 27 (2.3%) and six patients (0.5%), respectively. One of the patients with conversion to surgery had nodal recurrence, and five patients in the immediate surgery group had a recurrence in a cervical node or unresected thyroid lobe. All of these recurrences were successfully treated. None of the patients had distant metastases, and none died of the disease. The immediate surgery group had significantly higher incidences of transient vocal cord paralysis (VCP), transient hypoparathyroidism, and permanent hypoparathyroidism than the active-surveillance group did (4.1% vs. 0.6%, p < 0.0001; 16.7% vs. 2.8%, p < 0.0001; and 1.6% vs. 0.08%, p < 0.0001, respectively). Permanent VCP occurred only in two patients (0.2%) in the immediate surgery group. The proportion of patients on L-thyroxine for supplemental or thyrotropin (TSH)-suppressive purposes was significantly larger in the immediate surgery group than in the active surveillance group (66.1% vs. 20.7%, p < 0.0001). The immediate surgery group had significantly higher incidences of postsurgical hematoma and surgical scar in the neck compared with the active surveillance group (0.5% vs. 0%, p < 0.05; and 8.0% vs. 100%, p < 0.0001, respectively).Conclusions: The oncological outcomes of the immediate surgery and active surveillance groups were similarly excellent, but the incidences of unfavorable events were definitely higher in the immediate surgery group. Thus, active surveillance is now recommended as the best choice for patients with low-risk PMC.

Comparison of the costs of active surveillance and immediate surgery in the management of low-risk papillary microcarcinoma of the thyroid

“…In the present study, we created a model of the flow of the two management modalities, i.e., immediate surgery and active surveillance, for patients with low-risk PMC based on our previous study [10] of 2,153 patients with low-risk PMCs (Fig. 1).…”

“…We reported the outcomes of our clinical trial in several papers [5][6][7][8][9][10]. The active surveillance of 1,235 patients with low-risk PMCs revealed that only 8% of the patients showed an increase in tumor size by ≥3 mm, and only 3.8% of the patients showed novel nodal metastases at 10 years of observation [8].…”

“…In 1993 at a meeting of Kuma Hospital physicians, Akira Miyauchi proposed an observation clinical trial for low-risk PMC based on the following hypothesis: most PMCs remain small, and observation or surveillance without immediate surgery could identify the pared to the surveillance group [10]. In the present study, we calculated and compared the medical costs for these two management modalities for the diseases according to a model created from the actual flow of the managements of those 2,153 patients with lowrisk PMCs.…”

A Clinical Framework to Facilitate Risk Stratification When Considering an Active Surveillance Alternative to Immediate Biopsy and Surgery in Papillary Microcarcinoma

“…While a disease progression rate of approximately 10% is expected in this cohort, treatment offered at the time of disease progression will still be very effective and associated with excellent clinical outcomes when these patients are followed carefully by an experienced management team. At both Kuma Hospital and MSK Cancer Center, observation is routinely recommended for patients in this category, as ongoing studies demonstrate that even in a very experienced thyroid cancer center, immediate surgery is more likely to cause unfavorable outcomes (such as vocal cord paralysis and hypoparathyroidism) than an active surveillance management approach (23).…”

Wysoko zróżnicowany rak tarczycy — czy nie leczysz swoich pacjentów zbyt intensywnie?

“…The recent publication of two high-quality prospective randomised controlled trials scrutinising the use of high dose RAI [30,31] are to be followed by investigation of low-dose versus no RAI for low-risk WDTC [32]. It appears that the role of RAI is changing, and it is likely to be recommended in fewer patients in the low-risk group in the future.…”