Clinical management and outcome of papillary and follicular (differentiated) thyroid cancer presenting with distant metastasis at diagnosis.
BACKGROUND
Differentiated thyroid cancer has a good prognosis and only rarely presents with distant metastasis at diagnosis. The clinical outcome of this presentation was assessed with respect to survival and factors that may determine prognosis.


METHODS
A retrospective review was undertaken of patients with stage M1 differentiated thyroid cancer at presentation (n = 49), referred from 1980-2000 at a single institution.


RESULTS
The median age was 68 (range, 17-90), with 69% females. The initial site(s) of metastasis were lung only, 45%, bone only, 39%, other single site, 4%, and multiple sites, 12%.


RESULTS
papillary, 51%, follicular, 49%. Initial treatment(s) included: thyroidectomy, 82%, radioactive iodine (RAI), 88%, excision of metastasis, 29%, radiotherapy, 47%, and chemotherapy, 6%. With a median follow-up time of 3.5 years, 25 patients are alive (51%) and 24 died (49%), with 3-year and 5-year actuarial survivals of 69% and 50%, respectively. Only a minority of patients (4/25, 16%) had no clinical evidence of disease at last follow-up. Most deaths (17/24, 71%) were due to progressive cancer. Prognosis was associated with age, site of metastasis, histology, and iodine avidity of the metastasis. Patients aged </=45 (n = 8) had a 3-year survival of 100%, versus 62% for those age > 45 years (P = .001). The 3-year survival for lung only versus bone only metastasis was 77% versus 56% (P = .02); for papillary versus follicular carcinoma, 75% versus 62% (P = .006); for iodine-avid disease (n = 29) versus not avid (n = 14), 82% versus 57% (P = .02), respectively. In multivariate analysis after adjusting for age, only histology and iodine avidity remained significant for survival. The hazard ratio for follicular histology was 3.7 (95% confidence interval [CI], 1.1-12.1, P = .03), and for tumors not avid for iodine, 3.4 (95% CI, 1.2-9.2, P = .02).


CONCLUSIONS
The data support the aggressive management of patients presenting with stage M1 thyroid cancer, with thyroidectomy and RAI. Complete clinical eradication of disease was rarely seen, and 50% of patients survived for more than 5 years. Young patients with papillary tumors and/or iodine-avid disease have an even better prognosis.
Sampson
Elliot
E
Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Canada.
Brierley
James D
JD
Le
Lisa W
LW
Rotstein
Lorne
L
Tsang
Richard W
RW
D018263:Adenocarcinoma, Follicular / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000556:secondary; D002291:Carcinoma, Papillary / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*; D013965:Thyroidectomy; D016896:Treatment Outcome
D007457:Iodine Radioisotopes