Analyze recent clinical features of thyroid cancer in eastern China.

Investigation and comparison of clinical data of thyroid cancer patients from 1996 to 2006 from the Department of Head and Neck Surgery in the Cancer Hospital of Fudan University, Shanghai, China.

The number of patients with thyroid cancer rose from 148 in the year 1996 to 572 in the year 2006, a 3.9-fold increase. Routine ultrasound survey during physical examination revealed four cases (2.7%) in 1996 and 285 cases (49.8%) in 2006. The sensitivity of the ultrasound survey in thyroid cancer diagnosis was 86.66% in 1996 and 88.20% in 2006 (P>0.05). Papillary carcinoma was most prevalent (87.8% in 1996 and 92.8% in 2006). An increasing proportion of small tumors was found. The incidence of microcarcinoma was 35.7% in 2006 in contrast with 20.3% in 1996 (P<0.01). Moreover, tumors with diameter from 1 to 2cm were found in 38.5% patients in 2006 as opposed to 27.0% in 1996 (P<0.01). Extrathyroid extension was reported in 46 (31.1%) patients in 1996, but only in 39 (6.8%) in 2006 (P<0.01). Central cervical lymph node metastases were found in 98 (66.2%) patients in 1996, contrasting with 301 (52.6%) in 2006 (P<0.05). Thirty-seven (25.0%) patients had lateral cervical lymph node metastasis in 1996 compared with 117 (20.5%) in 2006 (P>0.05). Last, the proportion of stage I cancers in 2006 was higher than that in 1996.

With the increasing incidence of thyroid cancer, cancer was discovered at an earlier stage. This is due to new clinical features of thyroid cancer, such as the decrease in tumor diameter, the lower rate of extrathyroid extension and of cervical lymph node metastasis. Routine ultrasound survey during physical examination has become the most common way to detect thyroid cancer. Increasing usage of diagnostic scrutiny, including the ultrasound survey, has most likely contributed to the increased incidence through detection of small thyroid cancers. Increased use of ultrasound to screen thyroid cancer in early stages should lead to better therapeutic outcome.