Multifactorial analysis of survival and recurrences in differentiated thyroid cancer. Comparative evaluation of usefulness of AGES, MACIS, and risk group scores in Mexican population.

Many risk factors have been identified in differentiated thyroid cancer, with them, some prognostic scores have been designed to asign the risk of recurrence and survival. In Mexican population, this type of study is scarce. This is a retrospective review of 180 patients with differentiated thyroid cancer completely treated at the Hospital de Oncologia, IMSS, in Mexico City from 1980 to 1990. All prognostic factors were analyzed and a score obtained either by the method of AGES, MACIS, or SKMH. Correlation of recurrences and survival was carried out according to score or risk assignment. There was a predominance of females (4.8:1), 48% had metastatic cervical nodes, median tumor size was 4 cm, 16% had multiple macroscopic thyroid tumors, in 12% resection was incomplete, 96% were papillary, and 4% follicular cancers. According to AGES, 46% were high risk patients, 49.4% with MACIS and 45.5% with SKMH, respectively. Median follow-up was 8.3 years. There were 67 (37%) recurrences. Ten-year overall survival was 89.4% and disease-free survival was 79.2%. There was no statistical significant difference of survival of AGES until the score reached 6 or more or the MACIS score reached 8 or more. Cox multivariate model showed that above the age of 45, tumor size of 5 cm or more, follicular histology, multiple macroscopic thyroid tumors, and extracapsular node invasion affected ten-year survival. In conclusions our patients are diagnosed at more advanced stages than patients in the U.S. or European countries. Nearly one half of our patients belonged to the high-risk group. This study confirms that patients over the age of 45, tumor size > 5 cm, and follicular histology are adverse prognostic factors and report that extracapsular node invasion and multiple macroscopic thyroid tumors are also adverse prognostic factors. In Mexican population, with 50% of high-risk patients, AGES and MACIS scores reached statistical differences with higher qualifications than observed in the U.S.