This article is more than 5 years old. Information may no longer be current.
Cervical lymph node metastases compromise survival of younger patients with thyroid cancer
The presence of cervical lymph node metastases appeared to worsen survival in younger patients with papillary thyroid cancer, according to study results.
OS decreased with each additional nodal metastasis up to six, suggesting a need for rigorous preoperative screening for nodal metastases, according to the researchers.
Cervical lymph node metastases are currently recognized as a prognostic factor for patients with papillary thyroid cancer aged 45 years or older, according to study background. The current American Joint Committee on Cancer (AJCC) staging for younger patients with papillary thyroid cancer does not include cervical lymph node metastases.
Julie A. Sosa, MD, MA, chair of endocrine surgery at Duke University Medical Center, and colleagues conducted a retrospective cohort study to determine whether the presence and number of cervical lymph node metastases adversely impacted OS in patients with papillary thyroid cancer who did not have distant metastases and who were aged younger than 45 years.
Researchers used the National Cancer Data Base (NCDB; 1998-2006) to identify 47,902 patients — 11,740 (24.5%) of whom had nodal metastases — and the SEER database (1988-2006) to identify 21,855 patients, 5,188 (23.7%) of whom had nodal metastases.
Median follow-up was 83 months in the NCDB cohort and 116 months in the SEER cohort.
A total of 896 deaths occurred in the entire study population (NCDB, n = 539; SEER, n = 357). The presence of cervical lymph node metastases increased the risk for death in the NCDB (HR = 1.32; 95% CI, 1.04-1.67) and SEER cohorts (HR = 1.29; 95% CI, 1.08-1.56).
In the NCDB cohort, 20,628 patients had at least one lymph node examined. The researchers observed a significant association between mortality risk and number of metastatic lymph nodes (P = .046). An increased number of metastatic cervical lymph nodes up to six increased mortality risk (HR = 1.12; 95% CI, 1.01-1.25). However, any additional metastatic lymph nodes beyond six did not increase the mortality risk (HR = 0.99; 95% CI, 0.99-1.05).
Among 9,880 patients in the SEER cohort who had at least one cervical lymph node examined, the presence of up to six positive lymph nodes also increased the mortality risk (HR = 1.12; 95% CI, 1.02-1.22); however, any additional metastatic lymph nodes did not increase the mortality risk (HR = 0.97; 95% CI, 0.89-1.05).
Researchers also conducted sensitivity analyses to account for patients with assumed clinically negative but pathologically unexamined lymph nodes. Results showed patients with lymph node metastases continued to experience significantly compromised OS rates in the cohorts NCDB (HR = 1.53; 95% CI, 1.14-2.07) and SEER cohorts (HR = 1.5; 95% CI, 1.19-1.89).
The researchers identified the potential for coding errors as a limitation of their study.
“By using the current AJCC staging system, younger patients with cervical lymph node metastases may be understaged,” Sosa and colleagues concluded. “Our results suggest that cervical lymph node metastases should be considered in a revised AJCC staging system for papillary thyroid cancer among young patients. … These findings call for a rigorous preoperative screening approach with fastidious ultrasonography to determine lymph node status in young patients with papillary thyroid cancer.” – by Cameron Kelsall
Disclosure: Sosa reports receiving research funding from or other financial ties with AstraZeneca, GlaxoSmithKline, Novo Nordisk and OXiGENE. Please see the full study for a list of all other researchers’ relevant financial disclosures.