Method of Detection of Well-Differentiated Thyroid Cancers in Obese and Non-Obese Patients

Abstract

BackgroundThe incidence of well-differentiated thyroid cancer (WDTC) is increasing rapidly. Many authors feel that this increase is due to over-diagnosis and that one of the contributing factors is the increasing use of various imaging studies. The rate of obesity has also been increasing in the United States. It has been suggested that patients with an increased body mass index (BMI kg/m2) have a higher incidence of WDTC than patients with normal BMI. One might hypothesize that thyroid nodules are more difficult to palpate in obese patients and that as more cancers are detected by imaging the apparent rate of increase in WDTC in obese patients would appear to be greater than in non-obese patients. This study was undertaken to evaluate this hypothesis by determining if there is any difference in the way thyroid cancers are initially detected in obese and non-obese patients.MethodsThe medical records of all 519 patients with a postoperative diagnosis of WDTC who underwent thyroidectomy at NYU Langone Medical Center from January 1, 2007 through August 31, 2010 by the three members of NYU Endocrine Surgery Associates were reviewed. Patients were divided into Non-obese (BMI<30 kg/m2) and Obese (BMI≥30 kg/m2) groups. Patients were also divided by the initial method of detection of their tumor into Palpation, Imaging, and Incidental groups.ResultsThe final study group contained 270 patients, 181(67%) of whom were in the Non-obese Group and 89(33%) were in the Obese Group. In the Non-obese group, 81(45%) of tumors were found by palpation, 72(40%) were found by imaging, and 28(16%) were found incidentally. In the Obese group, 40(45%) were found by palpation, 38(43%) were found by imaging, and 11(12%) were found incidentally. These differences were not statistically significant (p-value 0.769).ConclusionWe show that BMI does not play a role in the method of initial detection in patients with WDTC. This suggests that the prevalence of WDTC detected by imaging is not an artifact caused by an increasingly obese population and that any association of WDTC and obesity is not related to the way in which these tumors are detected.

Survival Comparison of Incidentally Found versus Clinically Detected Thyroid Cancers: An Analysis of a Nationwide Cohort Study

“…After adjustment using IPTW, the clinical suspicion group had a 69% higher risk of death than the screening group. These results are consistent with previous studies comparing mortality between incidental and non-incidental thyroid cancer [1,[21][22][23][24][25][26][27][28][29][30].…”

Impact of Overweight and Obesity on US Papillary Thyroid Cancer Incidence Trends (1995–2015)

“…Greater delays in diagnosis among the obese participants (thus allowing for greater tumor growth) and/or more incidental detection of small PTCs among the normal-weight participants could also explain the patterns observed. On the other hand, a recent study found no difference in the method of initial detection of differentiated thyroid cancer (palpation, imaging, incidental) by obesity status ( 35 ). Without individual-level information on the pathways through which PTCs were detected and ultimately diagnosed in the NIH-AARP study, however, we could not fully evaluate or control for the effects of healthcare access and utilization on our results.…”

Anthropometric, dietary, and lifestyle factors and risk of advanced thyroid cancer: The NIH‐AARP diet and health cohort study

“…Some authors have argued that the BMI and thyroid cancer association is only due to detection bias, 26,27 although there is no evidence, to our knowledge, that individuals with high BMI are more likely to undergo thyroid cancer screening or have thyroid cancer incidentally detected 28 . It appears that detection bias does not fully explain the association between obesity and thyroid cancer, since in our study, we found a positive association between higher BMI and risk of thyroid cancer after restricting our analysis to HRTC.…”