Serum calcitonin nadirs to undetectable levels within 1 month of curative surgery in medullary thyroid cancer

ABSTRACT Objective: Because serum calcitonin (CT) is a reliable marker of the presence, volume, and extent of disease in medullary thyroid cancer (MTC), both the ATA and NCCN guidelines use the 2-3 month post-operative CT value as the primary response to therapy variable that determines the type and intensity of follow up evaluations. We hypothesized that the calcitonin would nadir to undetectable levels within 1 month of a curative surgical procedure. Subjects and methods: This retrospective review identified 105 patients with hereditary and sporadic MTC who had at least two serial basal CT measurements done in the first three months after primary surgery. Results: When evaluated one year after initial surgery, 42 patients (42/105, 40%) achieved an undetectable basal calcitonin level without additional therapies and 56 patients (56/84, 67%) demonstrated a CEA within the normal reference range. In patients destined to have an undetectable CT as the best response to initial therapy, the calcitonin was undetectable by 1 month after surgery in 97% (41/42 patients). Similarly, in patients destined to have a normalize their CEA, the CEA was within the reference range by 1 month post-operatively in 63% and by 6 months in 98%. By 6 months after curative initial surgery, 100% of patients had achieved a nadir undetectable calcitonin, 98% had reached the CEA nadir, and 97% had achieved normalization of both the calcitonin and CEA. Conclusion: The 1 month CT value is a reliable marker of response to therapy that allows earlier risk stratification than the currently recommended 2-3 month CT measurement.

Serum calcitonin nadirs to undetectable levels within 1 month of curative surgery in medullary thyroid cancer.

OBJECTIVE: Because serum calcitonin (CT) is a reliable marker of the presence, volume, and extent of disease in medullary thyroid cancer (MTC), both the ATA and NCCN guidelines use the 2-3 month post-operative CT value as the primary response to therapy variable that determines the type and intensity of follow up evaluations. We hypothesized that the calcitonin would nadir to undetectable levels within 1 month of a curative surgical procedure. SUBJECTS AND METHODS: This retrospective review identified 105 patients with hereditary and sporadic MTC who had at least two serial basal CT measurements done in the first three months after primary surgery. RESULTS: When evaluated one year after initial surgery, 42 patients (42/105, 40%) achieved an undetectable basal calcitonin level without additional therapies and 56 patients (56/84, 67%) demonstrated a CEA within the normal reference range. In patients destined to have an undetectable CT as the best response to initial therapy, the calcitonin was undetectable by 1 month after surgery in 97% (41/42 patients). Similarly, in patients destined to have a normalize their CEA, the CEA was within the reference range by 1 month post-operatively in 63% and by 6 months in 98%. By 6 months after curative initial surgery, 100% of patients had achieved a nadir undetectable calcitonin, 98% had reached the CEA nadir, and 97% had achieved normalization of both the calcitonin and CEA. CONCLUSION: The 1 month CT value is a reliable marker of response to therapy that allows earlier risk stratification than the currently recommended 2-3 month CT measurement.

Thyroid Cancer Treatment Choice: A Pilot Study of a Tool to Facilitate Conversations with Patients with Papillary Microcarcinomas Considering Treatment Options.

BACKGROUND: The 2015 American Thyroid Association guidelines recognize active surveillance as an alternative to immediate surgery in patients with papillary microcarcinomas (PMCs). As a way to incorporate active surveillance as one of the management options for patients with PMCs, we developed and tested a tool to support conversations between clinicians and patients with PMCs considering treatment options. METHODS: Thyroid Cancer Treatment Choice was developed using an iterative process based on the principles of interaction, design, and participatory action research. To evaluate the impact of the tool on treatment choice, a prospective study was conducted in two thyroid cancer clinics in Seongnam-si and Seoul, South Korea. Both clinics had the expertise to offer active surveillance as well as immediate surgery. One clinic was trained in the use of the conversation aid, while the other clinic continued to care for patients without access to the conversation aid. RESULTS: Between May 2016 and April 2017, 278 patients, mostly women (n = 220, 79%), were included in the study; 152 (53%) received care at the clinic using the conversation aid. Age, sex, and mean (±SD) tumor size (6.6 ± 1.6 mm and 6.5 ± 1.9 mm) distributions were similar across clinics. Overall, 233 (84%) patients opted for active surveillance and 53 (16%) for thyroid surgery. Patients in the conversation aid group were more likely to choose active surveillance than the patients seen in the usual care clinic (relative risk = 1.16 [confidence interval 1.04-1.29]). Of all patients opting for active surveillance, more patients in the conversation aid group had thyroid cancer nodules >5 mm than in the usual care group (81% vs. 67%; p = 0.013). CONCLUSIONS: Thyroid Cancer Treatment Choice is an evidence-based tool that supports the presentation of treatment options for PMCs. Pilot testing suggests that this conversation tool increases acceptance of active surveillance, suggesting that this option is an acceptable and preferable alternative for informed patients. Further studies are warranted to confirm this finding.

Treatment decision making in early-stage papillary thyroid cancer.

OBJECTIVE: The purpose of this study was to develop an in-depth understanding of papillary microcarcinoma (PMC) patients' decision-making process when offered options of surgery and active surveillance. METHODS: Fifteen PMC patients and 6 caregivers participated in either a focus group or individual interview. Focus groups were segmented by patients' treatment choice. Primary themes were identified in transcripts using thematic text analysis. RESULTS: Four themes emerged from the surgery subsample: (1) Decision to undergo thyroidectomy quickly and with a sense of urgency; (2) Perception of PMC as a potentially life-threatening disease; (3) Fear of disease progression and unremitting uncertainty with active surveillance; and (4) Surgery as a means of control and potential cure. Three themes emerged from the active surveillance subsample: (1) View of PMC as a common, indolent, and low-risk disease; (2) Concerns about adjusting to life without a thyroid and becoming reliant on hormone replacement medication; and (3) Openness to reconsidering surgery over the long run. Two themes were identified that were shared by participants from both subsamples: (1) Deep level of trust and confidence in physician and cancer center; and (2) Use of physician and internet as primary sources of disease and treatment-related information. CONCLUSIONS: Several factors influenced participants' treatment choice, with similarities and differences noted between surgery and active surveillance subsamples. Many of the emergent themes are consistent with research on decision making among localized prostate cancer patients. Findings suggest that participants from both PMC treatment subsamples are motivated to reduce illness and treatment-related uncertainty.

RAI thyroid bed uptake after total thyroidectomy: A novel SPECT-CT anatomic classification system.

OBJECTIVE: Recent, more selective use of radioactive iodine (RAI) has led to reevaluation of the clinical importance of achieving complete total thyroidectomy with minimal residual normal thyroid tissue. We utilize the improved localization by post-RAI remnant ablation, single photon emission computerized tomography-computed tomography (SPECT-CT) to define specific anatomic sites of residual RAI-uptake foci after total thyroidectomy for differentiated thyroid cancer (DTC) and to provide a novel classification system relating uptake to thyroid anatomy and preservation of adjacent neural structures. STUDY DESIGN: Retrospective. METHOD: Radioactive iodine-uptake foci in thyroid bed were localized by SPECT/CT imaging at the time of RAI remnant ablation in 141 DTC patients undergoing total thyroidectomy. RESULTS: Minimal residual RAI uptake (median 0.32% at 24 hours) in the thyroid bed was detected by diagnostic planar whole body scans in 93% and by posttherapy SPECT/CT imaging in 99% of subjects. Discrete RAI uptake foci were identified on the SPECT/CT imaging at Berry's ligament (87%), at superior thyroid poles (79%), in paratracheal-lobar regions (67%), in isthmus-region (54%), and in pyramidal lobe (46%). Despite the residual foci, the nonstimulated thyroglobulin (Tg) prior to remnant ablation (with a median thyroid-stimulating hormone of 0.36 m IU/L) was < 0.6 ng/mL in 53% and < 1 ng/mL in 73% of cases. CONCLUSION: After extracapsular total thyroidectomy, highly sensitive detection tools identify microscopic residual RAI avid foci in thyroid bed in the majority of patients. These foci can be classified as 1) neural-related and 2) capsule-related. These common residual foci have no relationship to postoperative Tg, suggesting that attempts at radical removal of thyroid tissue in these locations may not be warranted. LEVEL OF EVIDENCE: 4.