Routine node removal during thyroid cancer surgery shows benefit
Routine removal of neck lymph nodes during initial thyroid surgery for papillary cancer may lead to lower recurrence rates and lower levels of the thyroid tumor marker thyroglobulin.
Lymph nodes in the neck can be affected when thyroid cancer metastasizes, but problems may not be detected before or during surgical removal of the diseased thyroid. Neck lymph node removal—a procedure known as prophylactic central neck lymph node dissection (CLND)—is standard procedure in some cancer centers, but remains controversial. However, Michael W. Yeh, MD, an associate professor of surgery at the David Geffen School of Medicine at University of California, Los Angeles, and colleagues found that rates of cancer-related repeat surgery were lower in patients who underwent CLND.
As they reported in the journal Surgery (2011;150:1048-1057), Yeh and co-investigators conducted a retrospective, multicenter, cohort study using pooled data from three international endocrine surgery units in the United States, Australia, and England. All 606 patients had papillary thyroid cancer tumors larger than 1 cm without preoperative evidence of lymph node disease (cN0). The 347 patients in group A underwent total thyroidectomy alone, whereas the 259 patients in group B had total thyroidectomy plus CLND.
Stimulated thyroglobulin values were lower in group B before initial radioiodine ablation (6.6 vs 15.0 ng/mL), and there was a trend toward a lower thyroglobulin level in group B at final follow-up (1.9 vs 7.2 ng/mL), possibly representing a more thorough clearing of disease in these patients. The rate of disease recurrence in the entire study population was 6.9%, with the rate of repeat surgery in the central compartment significantly lower in group B (1.5 vs. 6.1).
These findings led Yeh's team to conclude that the addition of routine CLND in cN0 papillary thyroid carcinoma is associated with lower postoperative thyroglobulin levels and reduces the need for repeat surgery in the central compartment. The researchers calculated that the number of CLND procedures required to prevent one central compartment repeat surgery was 20.
The group B patients had significantly higher rates of temporarily low calcium levels, a common side effect, than did the group A members (9.7% vs 4.1%). The rate of long-term complications was low for both groups, at approximately 1%.