Management of patients with low-risk papillary thyroid carcinoma

Recurrence after treatment of micropapillary thyroid cancer

BACKGROUND

Despite very low mortality associated with micropapillary thyroid cancer, locoregional recurrence is common and controversy exists regarding optimal surgical treatment and the role of adjunctive radioiodine.

METHODS

The National Thyroid Cancer Treatment Cooperative Study Group Registry was analyzed for recurrences in patients with unifocal versus multifocal micropapillary cancer, with or without nodal disease, depending upon the extent of surgery and the use of adjunctive radioiodine. Six hundred eleven patients considered disease-free after initial therapy were followed for 2572 person-years.

RESULTS

Thirty patients (6.2%) had recurrences detected at a mean 2.8 years after primary treatment. Recurrences did not differ between patients with unifocal and multifocal disease overall; however, among patients who received less than a near-total thyroidectomy (NTT), those with multifocal disease had more recurrences than those with unifocal disease (18% vs. 4%, p = 0.01). Patients with multifocal disease who had a total (T) or NTT trended toward fewer recurrences than those undergoing less than an NTT (6% vs. 18%, p = 0.058). In patients who did not receive radioiodine therapy, recurrence was more common in patients with multifocal disease versus unifocal disease (7% vs. 2%, p = 0.02). However, radioiodine did not reduce recurrences in patients with multifocal disease or patients with positive nodes. Patients with positive nodes had more recurrences than node-negative patients regardless of surgical extent or use of radioiodine.

CONCLUSIONS

Patients with micropapillary multifocal disease have a reduced risk of recurrence after a T/NTT compared with less surgery. A randomized, controlled trial is necessary and feasible to determine if radioiodine ablation of thyroid remnants is advantageous in patients with intrathyroidal micropapillary cancer.

Classification of follicular cell tumors of the thyroid gland: analysis involving Japanese patients from one institute

Prognostic analyses of thyroid carcinomas of follicular cell origin were carried out on patients treated at Kuma Hospital, Kobe, Japan. A new histopathological classification based on the prognostic evidence is proposed in this study, and it is applicable to the patients treated curatively. Major histological types of papillary carcinoma, follicular carcinoma and poorly differentiated carcinoma were combined into one single entity of follicular cell adenocarcinoma because (i) they have the same cell origin (follicular cell); (ii) clear-cut separation of papillary and follicular carcinoma is not always possible, and 10 year cause-specific survival was essentially similar when the patients were treated curatively; and (iii) poorly differentiated carcinoma usually has a background of either papillary or follicular carcinoma. This adenocarcinoma together with undifferentiated carcinoma was stratified into four prognostic groups using pure morphological criteria of the degree of cellular differentiation and histological grade. They are termed well-differentiated adenocarcinoma, moderately differentiated adenocarcinoma, poorly differentiated carcinoma and undifferentiated carcinoma of the thyroid. The 10 year disease-free survival rates were 86.3-93.1%, 65.4-78.7%, and 43.0-53.8%, and 0%, respectively. The 10 year cause-specific survival rates were 97.2-100%, 91.5-97.4%, and 71.2-80.0%, and 0%, respectively.

The impact of thyroid cancer and post-surgical radioactive iodine treatment on the lives of thyroid cancer survivors: a qualitative study

Background

Adjuvant treatment with radioactive iodine (RAI) is often considered in the treatment of well-differentiated thyroid carcinoma (WDTC). We explored the recollections of thyroid cancer survivors on the diagnosis of WDTC, adjuvant radioactive iodine (RAI) treatment, and decision-making related to RAI treatment. Participants provided recommendations for healthcare providers on counseling future patients on adjuvant RAI treatment.

Methods

We conducted three focus group sessions, including WDTC survivors recruited from two Canadian academic hospitals. Participants had a prior history of WDTC that was completely resected at primary surgery and had been offered adjuvant RAI treatment. Open-ended questions were used to generate discussion in the groups. Saturation of major themes was achieved among the groups.

Findings

There were 16 participants in the study, twelve of whom were women (75%). All but one participant had received RAI treatment (94%). Participants reported that a thyroid cancer diagnosis was life-changing, resulting in feelings of fear and uncertainty. Some participants felt dismissed as not having a serious disease. Some participants reported receiving conflicting messages from healthcare providers on the appropriateness of adjuvant RAI treatment or insufficient information. If RAI-related side effects occurred, their presence was not legitimized by some healthcare providers.

Conclusions

The diagnosis and treatment of thyroid cancer significantly impacts the lives of survivors. Fear and uncertainty related to a cancer diagnosis, feelings of the diagnosis being dismissed as not serious, conflicting messages about adjuvant RAI treatment, and treatment-related side effects, have been raised as important concerns by thyroid cancer survivors.

Incremental value of diagnostic 131I SPECT/CT fusion imaging in the evaluation of differentiated thyroid carcinoma

OBJECTIVE

The purpose of this study was to determine the incremental value of (131)I SPECT/CT over traditional planar imaging of patients with differentiated thyroid carcinoma.

MATERIALS AND METHODS

Fifty-six planar and SPECT/CT scans were obtained for 53 patients. Forty-eight scans were diagnostic (131)I studies before first radioiodine therapy, four were diagnostic (131)I studies with recombinant human thyroid-stimulating hormone stimulation, and four scans were posttherapy (131)I studies. Two nuclear physicians interpreted central neck and distant activity on planar scans and reviewed SPECT/CT images to assess the incremental diagnostic value with respect to localization and characterization of focal activity and to evaluate reader confidence. One of the readers was unblinded and had access to clinical, imaging, histologic, and biochemical information.

RESULTS

Planar scans depicted 130 neck foci and 17 distant foci. At SPECT/CT these foci were further characterized as thyroglossal duct and thyroid bed remnant (n = 98), cervical nodal metastasis or local residual disease (n = 26), physiologic activity (n = 11), and distant metastasis (n = 12). Interobserver disagreement occurred on eight of 147 foci (5%). Because of superior lesion localization and additional anatomic information derived from the low-dose CT component, incremental diagnostic value with SPECT/CT over planar imaging was found for 70 of 147 foci (47.6%), including 53 of 130 neck foci (40.8%) and all 17 (100%) distant foci. Reader confidence increased regarding 104 of 147 foci (70.7%).

CONCLUSION

Iodine-131 SPECT/CT is useful for accurate evaluation of regional and distant activity in characterization of foci as residual thyroid tissue or nodal, pulmonary, or osseous metastasis. Suspected physiologic mimics of disease can be confirmed with increased reader confidence.

Should all patients with subcentimeter thyroid nodules undergo fine-needle aspiration biopsy and preoperative neck ultrasonography to define the extent of tumor invasion?

BACKGROUND

Decisions involving the management of patients with papillary microcarcinoma are complex. Here we review and consider the literature in this area including two studies published in this issue of Thyroid.

SUMMARY AND CONCLUSIONS

Thyroid nodules 5 mm or smaller have a high rate of false positive ultrasound findings and often yield inadequate cytology on fine needle aspiration biopsy (FNAB). We conclude that nodules of this size with no other clinical findings should not undergo routine FNAB, even if they appear ultrasonographically suspicious. Biopsying such small nodules evokes major patient anxiety and is likely to yield cytology that is insufficient for diagnosis, especially in the hands of inexperienced ultrasonographers. Periodic ultrasound examination, despite its shortcomings, is likely to be a better option for such patients since their small nodules may spontaneously disappear or fail to grow over time. Those that grow by at least 50% or more might be considered for FNAB, but only if they exceed 5 mm.

Surgical approaches to thyroid tumors

This article includes discussions of the surgical approach to benign and malignant disease and the role of prophylactic thyroidectomy and nodal dissection for medullary thyroid cancer. The controversy regarding the extent of dissection for differentiated thyroid cancer and the role of lymph node dissection are reviewed also. A description of the authors' surgical technique for thyroidectomy is detailed. Finally, several emerging technologies are introduced.