Current Tumor Staging Systems

Thyroid Factor

The Natural Thyroid Diet

Get Instant Access

Nine staging and tumor scoring systems have been proposed over the years (Table 12.1). The sheer number of staging systems underscores their lack of general acceptance. Most use patient age at the time of initial therapy and tumor factors to discriminate patients at high risk of dying from thyroid cancer (Table 12.1) [6-13]. In one study [11], four of the schemes that use age (EORTC, TNM, AMES, AGES) when applied to the papillary carcinoma survival data from the Mayo Clinic, were effective in separating low risk patients in whom cancer-specific mortality was 1% at 20 years from high risk

Thyroid Cancer Stage

Figure 12.1 Tumor recurrence 40 years (median 16.7 years) after thyroid surgery and thyroid hormone therapy with and without 131I ablation of uptake in the thyroid bed. Total thyroidectomy includes ipsilateral lobectomy, isthmusectomy, and near-total contralateral thyroidectomy; subtotal thyroidectomy is lobectomy with or without isthmusectomy. Patients undergoing total thyroidectomy had more advanced tumor stage than those undergoing subtotal thyroidectomy (ANOVA, P < 0.001). (Reproduced with permission from Mazzaferri EL, Kloos RT. Current approaches to primary therapy for papillary and follicular thyroid cancer. J Clin Endocrinol Metab 2001; 86(4):1447-1463. Copyright 2001, The Endocrine Society.)

Figure 12.1 Tumor recurrence 40 years (median 16.7 years) after thyroid surgery and thyroid hormone therapy with and without 131I ablation of uptake in the thyroid bed. Total thyroidectomy includes ipsilateral lobectomy, isthmusectomy, and near-total contralateral thyroidectomy; subtotal thyroidectomy is lobectomy with or without isthmusectomy. Patients undergoing total thyroidectomy had more advanced tumor stage than those undergoing subtotal thyroidectomy (ANOVA, P < 0.001). (Reproduced with permission from Mazzaferri EL, Kloos RT. Current approaches to primary therapy for papillary and follicular thyroid cancer. J Clin Endocrinol Metab 2001; 86(4):1447-1463. Copyright 2001, The Endocrine Society.)

patients in whom it was 30% to 40% at 20 years [10]. Twenty-year survival rates for patients with MACIS scores less than 6, 6 to 6.99, 7 to 7.99, and 8+ were 99%, 89%, 56%, and 24%, respectively. Another study, however, that categorized 269 patients with papillary carcinoma according to five different prognostic scoring schemes found that some patients in the lowest risk group for each scheme died of cancer [7]. This is particularly true of the schemes that simply categorize risk dichotomously as low or high [6,14]. Moreover, these schemes do not consider tumor recurrence and are inaccurate in predicting disease-free survival. The latest American Joint Committee (AJCC) TNM staging system [13] for thyroid cancer (Table 12.2) classifies even more patients as being at low risk than did the former version. Staging systems derived from multivariate analyses that do not take into account the effects of therapy assume that treatment does not alter outcome. This is very likely incorrect. Treatment is not factored into the multivariate analyses that underpin most of the prognostic scoring systems, a weakness highlighted by the authors of the first thyroid cancer scoring system ever to be devised

Table 12.1 Components of staging systems and rating schemes for defining risk category in patients with differentiated thyroid carcinoma

Variable at time

University of

Ohio State

of diagnosis

TNMab

EORTCb

AMESb

AGESc

MACISc

NTCTCSb

MSKab

Chicagoc

Universityb

Patient characteristics

Age

X

X

X

X

X

X

X

Sex

X

X

X

Tumor characteristics

Cell type

X

X

Size

X

X

X

X

X

X

X

Grade (histological)

X

X

Extrathyroidal

X

X

X

X

X

X

X

X

X

extension

Lymph node

Xd

X

X

X

metastases

Distant

X

X

X

X

X

X

X

X

X

metastases

Therapy characteristics

Incomplete

X

resection

a T, primary tumor,T1, <2cm;T2, >2cm to 4cm;T3, >4cm;T4a,any size tumor to invade subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve;T4b,tumor invades prevertebral fascia or encases carotid artery or mediastinal vessels; all anaplastic tumors are considered T4: T4a intrathyroidal anaplastic carcinoma surgically resectable,T4b extrathyroidal anaplastic carcinoma surgically unresectable; regional lymph nodes are the central compartment, lateral cervical and upper mediastinal lymph nodes, N1a, metastases to level IV (pretracheal, para-tracheal,and prelaryngeal/Delphian lymph nodes),N1b metastases to unilateral, bilateral,or contralateral cervical or superior mediastinal lymph nodes; M0 distant metastases absent, M1 distant metastases present. b Both papillary and follicular carcinoma. c Only papillary carcinoma.

d Not applied to patients with papillary or follicular carcinoma under 45 years. See footnote to Table 12.2. for definitions of study abbreviations.

Table 12.2 Scoring methods.TNM (American Joint Committee on Cancer [13]) staging varies with cell type and age. Undifferentiated (anaplastic) carcinomas are stage IV.

Stage

<45 years

Papillary or follicular

>45 years

Medullary

I

M0

T1+N0+M0

T1+N0+M0

II

M1

T2+N0+M0

T2+N0+M0

None

T3+N0+M0

T3+N0+M0

III

T1-3+N1a

T1+N1a+M0

T2+N1a+M0

T3+N1a+M0

None

T4a+N0+M0

T4a+N0+M0

T4a+N1a+M0

T4a+N1a+M0

IVA

T1+N1b+M0

T1+N1b+M0

T2+N1b+M0

T2+N1b+M0

T3+N1b+M0

T3+N1b+M0

T4a+N1b+M0

T4a+N1b+M0

IVB

None

T4b+Any N+M0

T4b+Any N+M0

IVC

None

Any T+Any N+M1

Any T+Any N+M1

EORTC (European Organization for Research and Treatment of Cancer) [9]. Age in years + 12 if male, +10 if medullary, +10 if poorly differentiated follicular, +45 if anaplastic, +10 if extending beyond thyroid,+15 if one distant metastases + 30 if multiple distant metastases. AMES (Age-Metastasis-Extent-Size) [6]. High risk is female > 50 years,male > 40 years,tumor > 5cm (if older age),distant metastases,substantial extension beyond tumor capsule (follicular) or gland capsule (papillary).

AGES (Age-Grade-Extent-Size) [10].Calculated from 0.5 x age in years (if >40), +1 (if grade 2), +3 (if grade 3 or 4),+1 (if extrathyroidal), +3 (if distant spread), +0.2 x maximum tumor diameter.

MACIS (Metastasis-Age-Completeness of resection, Invasion-Size) [11]. MACIS = 3.1 (if aged <39 years) or 0.08 x age (if aged >40 years), +0.3 x tumor size (in centimeters),+1 (if incompletely resected), +1 (if locally invasive), +3 (if distant metastases present). NTCTCS (National Thyroid Cancer Treatment Cooperative Study) [8]. Staging variables not scored quantitatively. University of Chicago system for papillary carcinoma [15]. Staging variables (part A) not scored quantitatively.

MSKis Memorial Sloan Kettering system [16,5] for papillary and follicular thyroid carcinoma,not scored quantitatively.Low risk: age <45,tumor <1-4cm,M0, low grade histology. Intermediate risk: age < 45, tumor <1-4cm, M0 low grade. Intermediate age > 45, tumor >4cm or invasive, M1 and/or high grade. High risk: age >45,tumor >4cm or invasive,M1 and/or high grade. The Ohio State system for papillary or follicular carcinoma [3]. Staging not scored quantitatively.

[9]. This explains why none of the risk stratification schemas provide sufficient information to make therapeutic decisions for individual patients regarding the extent of surgery. Their main use lies in stratifying patients in epidemi-ological studies to permit comparisons of different patient cohorts.

Was this article helpful?

0 0
Peripheral Neuropathy Natural Treatment Options

Peripheral Neuropathy Natural Treatment Options

This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.

Get My Free Ebook


Post a comment