Differentiated thyroid cancer: a retrospective analysis of 832 cases from Greece

OBJECTIVE To analyse the initial manifestations, pathological findings, the rapy, outcome and prognostic factors in patients with papillary and follicu lar carcinoma. PATIENTS 832 patients with well differentiated thyroid carcinoma managed in our department during a period of 30 years (1965-1995). Follow-up data wer e available for 609 patients for a mean of 5.5 years (range 1-38 years), th e remainder having been lost to follow-up. RESULTS The patients were 677 (81%) with papillary and 155 with follicular carcinoma. They were predominantly female (75%), presenting mainly with a s ingle nodule (53%), while at the time of diagnosis 72% had intrathyroidal c arcinomas (class I), 17% had nodal metastases (class II), 7% soft tissue in vasion (class III) and 4% distant metastases (class IV). Fifty-five percent of the patients had a complete thyroidectomy (36% had a near total or tota l thyroidectomy and 19% near total or total thyroidectomy plus block dissec tion), 36% received external radiotherapy and 94% had radioactive iodine as part of the treatment of the original disease. Kaplan-Meier survival analy sis was used to calculate both cancer related mortality and disease free su rvival in the patients followed-up. Although mortality (21 cancer-related d eaths) was slightly higher for follicular than papillary carcinoma (10% vs. 5% and 16% vs. 10% in 10-and 15-year survival, respectively) the differenc e was not statistically significant. Extent of disease at diagnosis, male s ex, tumour size and age > 60 years affected probability of cancer death. Co x's proportional hazard regression analysis for disease free survival showe d that adverse independent prognostic factors were, for papillary carcinoma , male sex, class II or higher, tumour size >1 cm and age >60 years, while for follicular, class III or higher, size >4 cm and age > 40 years. CONCLUSIONS We conclude that there is a higher prevalence of follicular car cinoma in our country probably due to a moderate degree of iodine deficienc y still existing in Greece. Age and extent of disease at diagnosis were imp ortant prognostic factors affecting morbidity and mortality, whereas sex, t umour features and histological type were of minor importance. All these pr ognostic factors and their relative importance should be taken in considera tion in the management of this disease.