Natural history of papillary thyroid microcarcinoma: Kinetic analyses on tumor volume during active surveillance and before presentation

Abstract

Background: We report on the growth of papillary microcarcinoma during active surveillance and before clinical presentation. Methods: We conducted a retrospective study of 169 patients with papillary microcarcinoma who were enrolled in active surveillance at our hospital between 20 0 0 and 2004. Patients were followed for a median of 10.1 years using serial ultrasonography (median, 12 examinations), used to calculate the tumor doubling time. To contextualize tumor growth rates during active surveillance, we calculated the hypothetical tumor doubling time before clinical presentation. To resolve the limitations in tumor doubling time, tumor doubling rates were inversely transformed into doubling rates. Results: The doubling rates (per year) during active surveillance (median: 0.0) were > 0.5, 0.1 to 0.5, −0.1 to 0.1, and < −0.1 in 5, 38, 97, and 29 cases, respectively. The proportions of tumors with rather rapid growth, slow growth, stable, and a decrease in size were 3%, 22%, 57%, and 17%, respectively. Conclusion: Tumor growth of papillary microcarcinomas varies from rather rapid growth to a decrease in size during active surveillance.

Lymph node metastasis in young and middle-aged papillary thyroid carcinoma patients: a SEER-based cohort study

“…In 2010, the Cancer Institute Hospital in Tokyo, Japan reported that of 300 PTMC lesions, 3% had decreased in tumor size during active surveillance [15]. Recent data show that the proportions of tumors which decreased in size was 17%, with a distribution of 15, 21, and 13% for age at presentation of ≤40, 41-60, and > 60 years, respectively [16]. A retrospective observational study from Italy [17] showed that 34.9% (15/43) of indeterminate and 3.8% (2/52) of suspicious lymph nodes had disappeared during follow-up.…”

Active surveillance for patients with very low‐risk thyroid cancer

“…In addition to demonstrating the safety of AS, these experiences with rapid growth and 38 patients [22%] with slow growth), while some cancers were noted to decrease in size (29 patients, 17%). 37 Further evaluation of these lesions among 1235 patients demonstrated low rates of growth and progression overall with respect to nodule size, appearance of new lymph node metastases, and progression to clinical disease. 34 However, young age (<40 years) was a notable independent predictor for nodule growth over time whereas older patients had very rare growth.…”

“…In a retrospective review of 169 patients undergoing AS over a period of 10 years, the authors noted a wide spectrum of behavior of PTMC lesions. While the vast majority of cancers remained unchanged in size (97 patients, 57%), a small number underwent more pronounced growth (5 patients [3%] with rapid growth and 38 patients [22%] with slow growth), while some cancers were noted to decrease in size (29 patients, 17%) . Further evaluation of these lesions among 1235 patients demonstrated low rates of growth and progression overall with respect to nodule size, appearance of new lymph node metastases, and progression to clinical disease .…”

Natural history of thyroid cancer suggests beginning of the overdiagnosis of juvenile thyroid cancer in the United States

“…Another study supports this assumption. During observation, most papillary microcarcinomas stop their growth, and some even shrink . Because to my knowledge no effects of radiation on health have been reported in Fukushima, most of the cases found in the FHMS are likely to be overdiagnosed.…”