Patient Age Is Significantly Related to the Progression of Papillary Microcarcinoma of the Thyroid Under Observation
- Study type
- Observational study
- Design
- Observational cohort study (periodic ultrasound follow-up) in patients with low-risk papillary thyroid microcarcinoma who chose observation without immediate surgery
- Sample size
- 1235 patients
- Source
- Thyroid® · 2014
In plain words
Some people have a very small, low-risk papillary thyroid cancer (smaller than about one centimetre) that can be watched with regular ultrasound scans instead of immediate surgery. In this Japanese study of 1235 patients, tumours grew or progressed more often in younger people and less often in older people. However, during follow-up no patient had spread to distant parts of the body or died of this cancer. Be sure to talk with your doctor about choosing observation or surgery.
Key results
Treatment arms and regimens
Observation without immediate surgery, with ultrasound once or twice a year; surgery was recommended if there were signs of progression (significant enlargement or appearance of lymph node metastasis). TSH suppression with levothyroxine at the physician's preference in 2 patients in this group.
Observation without immediate surgery, with ultrasound once or twice a year; surgery was recommended if there were signs of progression (significant enlargement or appearance of lymph node metastasis). TSH suppression with levothyroxine at the physician's preference in 24 patients in this group.
Observation without immediate surgery, with ultrasound once or twice a year; surgery was recommended if there were signs of progression (significant enlargement or appearance of lymph node metastasis). TSH suppression with levothyroxine at the physician's preference in 25 patients in this group.
Source of the regimen details: Full text of the paper in PMC (PMC3887422); this is an observational cohort study with no drug treatment.
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
1235 patients at Kuma Hospital (Japan) with low-risk subclinical papillary thyroid microcarcinoma (PTMC; 10 mm or smaller, diagnosed by ultrasound-guided FNAB) who chose observation without immediate surgery between 1993 and 2011 and were followed for at least 18 months. Criteria for not offering observation (immediate surgery): regional lymph node or distant metastasis, signs of invasion of the recurrent laryngeal nerve or trachea, FNAB findings suggesting high-grade malignancy, and a tumour adjacent to the recurrent nerve or trachea. 90% were women; tumour size was 5 mm or less in 26%, more than 5 to 8 mm in 56% and more than 8 to 10 mm in 18%. Age groups at the start of observation: young (under 40 years, 169 patients), middle-aged (40 to 59 years, 570 patients) and older (60 years and over, 496 patients).
Endpoints
PTMC progression was assessed with three measures: (1) tumour enlargement (an increase in size of 3 mm or more from the start of observation), (2) novel appearance of lymph node metastasis (confirmed by FNAB and thyroglobulin measurement in the needle washout fluid), and (3) progression to clinical disease (tumour size reaching 12 mm or more, or novel appearance of lymph node metastasis).
Safety and side effects
The abstract gives no information on adverse events (grade 3 or higher). During observation, no patient developed distant metastasis or died of PTC.
Clinical significance and place in guidelines
These findings suggest that older patients with low-risk subclinical PTMC may be the best candidates for active surveillance. Progression is more common in younger patients, but according to the abstract, surgery after progression to clinical disease may still not be too late. The place of this approach in current guidelines should be checked separately, and decisions should be individualised and made with the treatment team.
Limitations
Observational, single-centre design; observation was chosen by the patients themselves; TSH suppression was used in only 51 patients (4%), at the physician's preference, which limits assessment of its effect; mean follow-up was 75 months.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.