Ini7al Staging of Follicular Cell-derived Thyroid Cancers: the ATA 2015 IRS and AJCC 8th Ed. Cancer Staging Systems

Transcription

1 12/25/17 9th Annual AACE Advances in Thyroid Cancer Course Tempe, Arizona January 12-13, Ini7al Staging of Follicular Cell-derived Thyroid Cancers: the ATA 2015 IRS and AJCC 8th Ed. Cancer Staging Systems Brian W Kim, MD Rush University Medical Center Chicago, IL 9th Annual AACE Advances in Thyroid Cancer Course, January 12-13, 2018; Tempe AZ Dr. Brian W Kim has no industry disclosures. Objec7ves/Overview: 1. Understand how iniaal risk straaficaaon is organized in ATA 2015 Guidelines and how it has changed from Understand how AJCC TNM (and other) systems [ MORTALITY ] fit with the ATA IRS system [ RECURRENCE ] 3. Understand the implicaaons of the changes in AJCC TNM 8th EdiAon (from the 7th Ed.) (Dynamic Risk StraAficaAon later!) PracAcal Importance of Risk Groups? I. PART ONE: WHAT S NEW IN ATA 2015 FOR INITIAL RISK STRATIFICATION (IRS SYSTEM) Why is it important to risk straefy? - To prognosacate be_er - To determine the intensity of surveillance - To determine the intensity of TSH suppression - To help decide whether to give I-131 (Rec 51) - To help decide if comple7on surgery is warranted - For inclusion of paaent data in Registries RISK OF RECURRENCE 1

2 12/25/ American Thyroid Associa7on Management Guidelines for Adult Pa7ents with Thyroid Nodules and Differen7ated Thyroid Cancer RISK of STRUCTURAL DISEASE RECURRENCE The American Thyroid AssociaAon (ATA) Guidelines Taskforce 101 RecommendaAons 133 pages 1078 references 2009 ATA IRS low risk Papillary Thyroid Cancer (with all of the following) No local or distant metastases All macroscopic tumor has been resected No tumor invasion of locoregional Assues or structures The tumor does not have aggressive histology (e.g., tall cell, hobnail variant, columnar cell carcinoma) No vascular invasion QuesAon: Papillary Thyroid Cancer: Classical variant 1.5 cm Intrathyroidal No margin involvement No vascular invasion 4 lymph nodes with microscopic PTCA IRS group? 2015 ATA low risk: proposed changes (1) Papillary Thyroid Cancer: Clinical N0 or 5 Pathologic N1 micrometastases (<0.2 cm in largest dimension)* = low risk Characteristics of CLN metastases have implications on recurrence risk of PTC N.b. Sabra and Tu^le 2013 on MSKCC use of I-131: OK to defer if post-op TG normal and only small volume cervical LN metastases defined as < 10 involved nodes if all are < 5 mm, or <5 if majority are 5-15 mm, and none >15mm Randolph et al for the ATA Surgical Task Force 2

3 12/25/ ATA low risk changes (2) Papillary Thyroid Cancer (with all of the following) Intrathyroidal, encapsulated follicular variant of papillary thyroid cancer (tomorrow AM talk) Intrathyroidal, well differenaated FTC with only capsular invasion Intrathyroidal, well differenaated FTC with only minor vascular (<4 foci) invasion Intrathyroidal, papillary microcarcinoma, unifocal or mulafocal, including V600E BRAF mutated (if known)* BRAF: not so bad in Any PTCA? 2015 Rec 48C: Since BRAF mutaaonal status appears to add li_le incremental prognosac value to clinicopathological staging systems, BRAF tes7ng is not rou7nely recommended for ini7al post-opera7ve risk stra7fica7on in DTC. (Weak recommendaaon, Moderate-quality evidence) +BRAF in microcarcinomas doesn t seem to increase risk of recurrence (unless +ETE) (2015 Fig 4: if PTCA > 1cm; BRAF+ --> ~10% risk; associates with more aggressive features) Ongoing trials look at BRAF in otherwise LOW risk PTC 2015: Intermediate Risk and changes Microscopic invasion of tumor into the perithyroidal sow Assues* [contrast with AJCC] Clinical N1 or >5 Pathologic N1 with all involved lymph nodes < 3 cm in largest dimension RAI avid metastaec foci in the neck on the first post-treatment whole-body RAI scan Aggressive histology (e.g., tall cell, hobnail variant, columnar cell carcinoma) Papillary thyroid cancer with vascular invasion. [Intrathyroidal, papillary thyroid cancer, primary tumor 1-4 cm, V600E BRAF mutated (if known)*] MulEfocal papillary microcarcinoma with extrathyroidal extension and V600E BRAF mutated (if known)* 2015: High Risk proposed changes Macroscopic invasion of tumor into the perithyroidal sow Assues (gross ETE) Incomplete tumor resecaon Distant metastases PostoperaAve serum thyroglobulin suggesave of distant metastases Pathologic N1 with any metasta7c lymph node > or = 3 cm in largest dimension Follicular thyroid cancer with extensive vascular invasion (> 4 foci of vascular invasion) Risk Group Changes Require ValidaAon - The 2015 proposed risk assignment changes require confirmatory studies - Do the new groups truly sort the paaents be_er in terms or prognosacaang disease-free survival/recurrence? II. PART TWO: WHAT S NEW IN AJCC 8 TH EDITION CANCER STAGING SYSTEM RISK OF DEATH, REFINED 3

4 12/25/17 AJCC Cancer Staging Manual, 8th Ed (2016) AJCC Cancer Staging Manual American Joint Commi_ee on Cancer 22 organizaaons including College of American Pathologists MulAdisciplinary expert commi_ee: TUTTLE RM, MORRIS LF, HAUGEN BR, SHAH JP, SOSA JA, ROHREN E, SUBRAMANIAM RM, HUNT JL, PERRIER ND Chapter 73: Thyroid-DifferenAated and AnaplasAc Carcinoma Tu_le, Haugen, Perrier The Updated AJCC/TNM Staging System for DifferenAated and AnaplasAc Thyroid Cancer (8th ediaon): What changed and why? Thyroid 2017, in press AJCC and FCD Thyroid Cancer 7th EdiAon TNM Staging AJCC Staging is for predicang SURVIVAL Most cancers have anatomic only staging for mortality; this doesn t make sense for thyroid cancer FCDTC staging in AJCC incorporates histology and age (unique) AJCC-TNM has one of the highest "propor7ons of variance explained" (how well it predicts outcome of interest) thus ATA and NCCN use it (ATA 2015 Rec 47) Required for some registries: implementaaon target date (for registries): Jan 1, 2018 Note: iniaal staging concludes 4 months post-op AJCC 8th Ed: What Changed and Why? Age, Microscopic Extension, Nodes Expert commi_ee literature review led to changes designed to improve prognosac performance of the AJCC staging system Mostly, changes lead to downstaging (fewer Stage III pa7ents, having moved to II or I) reflecang the low risk of dying of the downstaged paaents AJCC 8th Ed Chapter 74: Table 1 (DTC) 1. The age cutoff used for staging was increased from 45 to 55 years of age at diagnosis. 2. Minor extrathyroidal extension detected only on histological examinaaon was removed from the definiaon of T3 disease and therefore has no impact on either T category or overall stage. 3. N1 disease no longer upstages a paeent to stage III. If < 55 years of age at diagnosis, N1 disease is stage I. If 55 years of age, N1 disease is stage II. Tu_le/Haugen/Perrier, Thyroid

5 12/25/17 AGE conanuous awer ~35 1. The age cutoff used for staging was increased from 45 to 55 years of age at diagnosis. This doesn t change mortality much of the Stage Groups (Nixon et. al. 2016) However, recognizes that awer age ~35, mortality increases in the manner of a conanuous variable Should improve the DISTRIBUTION of paaents in the groups, be_er reflecang biology (e.g. many older paaents sall have low risk of DS death) Effect of Age Downstaging (Nixon et. al. MulA-InsAtuAonal study) NIXON et al Thyroid 2016 AJCC 8 th Ed Chapter 74: Table 1 (DTC) 2. Minor extrathyroidal extension detected only on histological examinaaon was removed from the definiaon of T3 disease and therefore has no impact on either T category or overall stage. Extension: minor is... minor 2. Minor extrathyroidal extension detected only on histological examinaaon was removed from the definiaon of T3 disease and therefore has no impact on either T category or overall stage. GROSS extension (clinical/radiologic) does associate with poorer outcomes and drives upstaging (T3B = Stage 2, T4a = Stage 3, T4b = Stage 4) Nodes: no longer T3 (!) 3. N1 disease no longer upstages a paeent to stage III. If < 55 years of age at diagnosis, N1 disease is stage I. If 55 years of age, N1 disease is stage II. Impact of nodal mets in <55 years is significant but relaavely minor (Adam et. al./sosa Thyroid 2015) Impact of nodal mets is worse in older paaents Note: lymph node assessment does not require histologic confirmaaon (rouane pre/interop workup enough) Future revision: extranodal extension not yet a factor? AJCC 8 th Ed Chapter 74:Table 1 CONTINUED 4. T3a is a new category for tumors > 4 cm confined to the thyroid gland 5. T3b is a new category for tumors of any size demonstraang gross extrathyroidal extension into strap muscles (sternohyoid, sternothyroid, thyrohyoid, or omohyoid muscles) 6. Level VII lymph nodes, previously classified as lateral neck lymph nodes (N1b) were re-classified as central neck lymph nodes (N1a) to be more anatomically consistent and because level VII presented significant coding difficulaes for tumor registrars, clinicians, and researchers. 7. In differenaated thyroid cancer, the presence of distant metastases in older paaents is classified as IVB disease rather than IVC disease. Distant metastasis in anaplasac thyroid cancer conanues to be classified as IVC disease. 5

6 12/25/17 Analysis: Comparing AJCC 8th and 7th Ed AGE EFFECT on YOUNG: 1% or less paaents will go from IV to II; these have only 68% 10-yr survival (e.g M1); but since very few, overall impact on Stage II survival should be small Kim TH et al, Oral Oncology 2017; SAMSUNG MEDICAL CENTER In older paaents, sig differences 7 v 8: <4 cm intrathyroidal: all Stage I since no survival difference based on prior 2 cm cutoff >55 pts with +nodes, OT gross invasion of overlaying strap muscles are Stage II; since older, survival will be worse than Stage I Since Stage III now enriched with worse prog features, (gross extension) survival will be predicted to be worse than the prior (7th Ed) IV a - (similar for IV) Comparing AJCC 8th and 7th Ed Note on AnaplasAc (Table 1) 1. Unlike previous ediaons where all anaplasac thyroid cancers were classified as T4 disease, anaplasac cancers will now use the same T definiaons as differenaated thyroid cancer. 2. Intrathyroidal disease is stage IVA, gross extrathyroidal extension or cervical lymph node metastases is stage IVB, and distant metastases are stage IVC PonAus and Sosa 2017 Staging Approach Thank You!!! IniAal Mortality IniAal means: within 4 months of surgery (for iodine info) AJCC TNM now V8 Risk of Recurrence ATA 2015 Revised risk as Ame progresses ATA 2015 DNS 6