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Age, tumor size may predict papillary thyroid carcinoma recurrence
For adults aged 55 years and older, tumor size can be an accurate means to predict recurrence of papillary thyroid carcinoma, with every 1-cm increase equating to a 52% increase in recurrence risk, according to study findings.
“The prognosis of papillary thyroid carcinoma (PTC) is excellent, with disease-specific survival rates exceeding 90%,” Ardalan Ebrahimi, MBBS, head and neck surgeon at the Sydney Head and Neck Cancer Institute, and colleagues wrote. “However, recurrence remains a problem in up to 30% of patients.”
Researchers conducted a retrospective database review of data from 574 patients with papillary thyroid cancer (455 women; median age, 47.7 years; age range, 14.9-86.9 years) who underwent surgery for PTC at Liverpool Hospital in Sydney from 1987 to 2016 to examine whether disease recurrence can be predicted by patient age or tumor size. Patients were divided into groups according to age at surgery: age younger than 55 years (n = 164) and age 55 years and older (n = 409). Follow-up was a mean of 4.6 years.
Among the cohort, 534 patients underwent total thyroidectomy, 38 hemithyroidectomy and two isthmusectomies; 393 patients underwent radioactive iodine therapy following surgery.
Overall, there were 67 recurrences of papillary thyroid cancer; and for every 1-cm increase in tumor size, researchers observed a 16% increase in the potential risk for recurrence. Most instances of recurrence appeared within roughly 2 years, although in one instance, disease recurrence was not evident until 14 years after surgery.
The findings diverged once age became a variable. The effect of tumor size on recurrence was particularly pronounced with older participants. For every 1 cm in tumor size, there was a 52% jump in recurrence risk. The researchers noted that a tumor of 2 cm was the cutoff for projection, and that tumors larger than 2 cm were five times more likely to lead to recurrence than tumors smaller than 2 cm. Younger participants did not exhibit similarly statistically significant evidence that tumor size could predict recurrence.
Practical applications of these findings could potentially influence clinicians when choosing the correct course of treatment, as tumor size has been the predominant determining factor, according to the researchers. This could further affect decisions about surgery and use of adjuvant radioactive iodine therapy, they wrote.
“Many clinicians base decisions regarding extent of surgery, including suitability for lobectomy vs. total thyroidectomy and the role of prophylactic central neck dissection, largely on tumor size without consideration of patient age,” the researchers wrote. “Similarly, the administration and dosing of adjuvant radioactive iodine may need to be reconsidered in the context of the patient’s age if the main adverse feature is primary tumor size. Finally, our results may also help provide guidance on the intensity of surveillance post treatment by more accurate risk stratification.” – by Phil Neuffer
Disclosures: The authors report no relevant financial disclosures.