Response to Therapy Status Is an Excellent Predictor of Pregnancy Associated Structural Disease Progression in Patients Previously Treated for Differentiated Thyroid Cancer

Program: Abstracts - Orals, Poster Previews, and Posters
Session: SAT 270-310-Thyroid Neoplasia (posters)
Clinical/Translational
Saturday, April 2, 2016: 1:15 PM-3:15 PM
Exhibit/Poster Hall (BCEC)

Poster Board SAT 302

9255 10469
Luba Rakhlin*1, Stephanie Fish2 and R Michael Tuttle2
1Weill Cornell/Memorial Sloan Kettering Cancer Center, New York, NY, 2Memorial Sloan Kettering Cancer Center, New York, NY
Nearly all of the follow-up management recommendations in the 2015 ATA thyroid cancer guidelines rely on response to therapy assessments which guide a risk adapted management approach.  While previous studies have suggested that pregnancy may be associated with a minor increase in the risk of disease progression/recurrence in patients previously treated for differentiated thyroid cancer (DTC), it remains unclear if the impact of pregnancy would differ between patients classified as having an excellent, incomplete, or indeterminate response to therapy immediately prior to pregnancy. To address this issue, we conducted a retrospective review of 235 women completing a full term pregnancy a median of 3 years after initial treatment for thyroid cancer (median age at delivery was 34 years old, 84% were 2009 ATA intermediate risk, 89% had total thyroidectomy, 61% had RAI remnant ablation, 74% were papillary thyroid cancer).  Prior to pregnancy, 63% were classified as having an excellent response, 16% had a structural incomplete response, 12% had an indeterminate response and 9% had a biochemical incomplete response.

Overall, structural disease progression/recurrence after pregnancy was documented in only 5% (11/235) of the patients with no significant change in the mean serum thyroglobulin levels (3.8 +/- 27 ng/mL pre-partum vs 3.7 +/-15 ng/mL post-partum).  When evaluated 3-12 months after delivery, none of the patients with excellent, indeterminate or biochemical incomplete response developed structurally identifiable disease.   Conversely, in those patients documented to have a structural incomplete response to therapy prior to pregnancy, structural disease progression (defined as ≥3mm increase in the size of known disease or identification of new metastatic foci) was identified after delivery in 29% (11/38):  13% with a 4-6 mm increase in the size of previously identified abnormal cervical lymph nodes, 8% with newly identified abnormal cervical lymph nodes, 5% with both increase in previously identified and newly identified abnormal cervical lymph nodes and one patient (3%) with an increase in known pulmonary metastases.  However, additional therapy was recommended during the first post-partum year in only 8% (3/38) of those patients that had a structural incomplete response to therapy prior to pregnancy while the remainder (92%) continued to be followed with observation.

In summary, none of the patients with an excellent, indeterminate or biochemical incomplete response prior to pregnancy developed structurally identifiable disease after a full term delivery.  Furthermore, only 8% of patients with a structural incomplete response to therapy required additional therapies during the first post-partum years.  These data confirm that pre-pregnancy response to therapy status is an excellent predictor of pregnancy associated disease progression in patients previously treated for DTC.

Disclosure: RMT: Consultant, Veracyte, Inc., Consultant, Astra Zeneca, Consultant, Bayer, Inc., Consultant, Eisai, Consultant, Genzyme Corporation, Consultant, Novo Nordisk. Nothing to Disclose: LR, SF

*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting/pr-resources-for-endo