Оксифільноклітинний рак щитоподібної залози: клініки, діагностика, лікування, прогноз

SUMMARY

Kushchayeva Yevgeniya Stanislavovna. Oxyphilic cell cancer: clinical behavior, diagnostic, treatment, prognosis. - Manuscript.

Dissertation for Candidate of Medical Sciences Degree, Speciality 14.01.14 - Endocrinology. - V.P. Komisarenko Institute of Endocrinology and Metabolism, Academy of Medical Science of Ukraine, Kyiv, 2008.

Dissertation is devoted to investigation of oxyphilic cell cancer's peculiarities and works out of rational protocol for treatment and diagnostic such kind of patients for improving treatment effectiveness.

Оxyphilic cell cancer differ from papillary and non-oxyphilic follicular cancer what include older age, higher level of extrathyroidal invasion, earlier metastases development, insensitivity to I¹³¹-treatment procedures and only surgery as effective cure method of disease.

According to morphologic features oxyphilic cell cancer has the inclination to extrathyroid spreading, lymph vessels and parenchyma invasion as papillary thyroid cancer and to blood vessels, tumor's capsule invasion as follicular thyroid cancer. Thus oxyphilic cell cancer has ability to involve lymphatic and blood ways for metastases spreading.

The effective diagnostic method of oxyphilic metastases is ^99mТс-pertehnetat and ^99mТс-MIBI scan. The advantages of ^99mТс-MIBI: low irradiation dose, possibility use higher activity, absent of dependence of ^99mТс-MIBI uptake of functional condition of thyroid gland, using some drugs which have influence on thyroid tissue. ^99mТс-MIBI using does not require thyroid hormone withdrawn and can be useful when remaining thyroid tissue is present. «Stunning» phenomenon after ^99mТс-MIBI administration is absent but with I¹³¹ using can be observed. According to our investigation effectiveness of ^99mТс-MIBI for I¹³¹-negative metastases is 77%.

Low sensitivity of oxyphilic cell cancer to I¹³¹ was proved by this work. None of cases with metastases did not show I¹³¹ uptake sufficient for treatment effect.

Only surgery was effective method for oxyphilic cell cancer metastases.

Analysis of follow-up showed higher level of metastases among oxyphilic cell cancer cases (11.4%) if compare with papillary (3.8%) and follicular thyroid cancer (3.8%). Period oxyphilic cell cancer metastases appearance after operation was shorter (1.5 years) than for papillary (1.9 years) and follicular cancers (2.5 years).

Related cancer death among oxyphilic cell cancer patients was highest (4.5%) comparison with papillary (0.6%) and follicular (0.7%) thyroid cancers.

Among significant prognostic factors extrathyroidal extension (Т₄), wide invasive tumor and initial metastases are present.

Taking into consideration peculiarities of clinical behavior of oxyphilic cell cancer the algorithm of treatment and follow-up was worked out. The algorithm includes total thyroidectomy, remaining tissue ¹³¹I-ablation and patient observation with using thyroglobulin level, neck US, CT and/or MRI, ^99mТс - pertehnetat and ^99mТс-MIBI scan, especially in cases of ¹³¹I-negative metastases.

Risk factors among oxyphilic cell cancer patients were investigated. More aggressive behavior was seen among patients older than 45 years. These patients had metastases and cancer-related death in 15.6% and 6.3% cases in comparison with 0% for younger patients (< 45 years). The influence of gender on prognosis is under discussion. Among investigated cases only women had metastases (13.5%, 5/37) and death 5.4% (2/37). Size of tumor according to our investigation did not play significant role in the prognosis: 15.4% metastases with primary tumor size > 4 cm and 10% - < 4 сm.

Only patients with wide invasive oxyphilic cell cancer had metastases and death cases (35.7%, 5/14 and 14.3%, 2/14, respectively). Most tumors with extrathyroidal spreading were detected with metastatic process more frequent (66.7%, 4/6) than tumors surrounding by thyroid tissue (2.6%, 1/38). Cancer-related death was 32.3% (2/6) for T₄ tumors and 0% - for Т_1-3. Initial and late metastases are strongly associated with worse prognosis. Among investigated patients 57% cases (4/7) with initial metastases developed late metastases if compare with patients without initial metastases (2.6%; 1/37). Type of operation did not significant influent on metastases appearance and death being 13.3% (4/30) and 7.1% (1/14) after total thyroidectomy and 3.3% (1/30) and 7.1% (1/14) after operation less than thyroidectomy.

Total thyroidectomy is favorable for patients with oxyphilic cell cancer which can improve control metastases appearance after operation.

Among significant prognostic factors extrathyroidal extension (Т₄), wide invasive tumor and initial metastases are present.

Key words: oxyphilic cell cancer, ¹³¹I-resistant metastases, ^99mТс - pertehnetat and ^99mТс-MIBI scan, algorithm of treatment and follow-up of patients.