Features of Diagnosis and Surgical Treatment of Patients with Thyroid Cancer in Patients of Pensionage and Advanced Age

The research is dedicated to the problem of optimizing the diagnosis and surgical treatment of thyroid cancer in patients of pensionage and advanced age. The relevance of the study is due to the increasing incidence of thyroid cancer, particularly in radioactively contaminated territories, as well as the difficulties of early diagnosis and insufficient study of optimal volumes of surgical intervention in persons over 60 years of age. The work presents a comparative analysis of active and passive diagnostic tactics, an evaluation of the reliability of fine-needle biopsy with ultrasound control, and an determination of the structure of histological types of the tumor depending on age and region of residence. Data were obtained on the optimal volumes of radical surgical treatment, the structure of postoperative complications, and the possibilities of repeat operative interventions in case of recurrence of the disease.

Mortality among the population due to oncological diseases and the increase in the number of patients of pensionage and advanced age have made geriatric surgery one of the urgent problems of modern medicine. Currently, persons of the older age group and pensioners make up one-fifth of the total population of the country, including about 31% — at the age of over 80 [33]. It is noted that more than half of all malignant neoplasms are detected in persons over 70 years of age [148].

The most pronounced dynamics are observed in thyroid cancer (TC) [83, 100, 101]. It has been found that age-specific morbidity rates increase with age. It is presumed that the age factor is constituted not only by the hormonal homeostasis of the organism, but also by the biological features of the gland itself, including its proliferative potential and pathology [56, 99]. Currently, a significant increase in the incidence of TC is noted in all countries of the world. The relevance of this topic has acquired in connection with the increase in the incidence of TC in radioactively contaminated territories after the accident at the Chernobyl Nuclear Power Plant (ChNPP) [43, 86, 74, 84, 90, 92, 95].

The interest in the problem of TC in patients of pensionage and advanced age is caused by the difficulty of early diagnosis [4, 56]. According to literary sources, among patients operated for nodular goiter, 2–5% are found to have cancer [80, 57, 69, 94, 117, 140].

The question of the optimal volume of surgery for TC remains unresolved to this day [5]. On the specified problem, monographs, atlases have been published, a huge number of articles have been published, however, the main part of the research is devoted to children, adolescents, and patients of middle age. Publications on this problem in persons over 60 years of age are extremely few and contradictory. Thus, the question of the optimal volume of surgical treatment in elderly patients with primary TC remains insufficiently studied [5].

The literature is insufficiently represented with a comparative analysis of benign diseases of the thyroid gland preceding cancer in patients of pensionage and advanced age living in radioactively contaminated and conditionally "clean" territories.

Currently, there are no works defining the ratio of histological types of TC depending on the age of patients and their region of residence. The structure of postoperative complications after interventions on the thyroid gland due to cancer, depending on the age of patients, remains insufficiently studied. The possibilities of performing repeat surgical interventions in case of recurrence of TC in patients of pensionage and advanced age have also not been studied.

THE AIM OF THE RESEARCH: optimization of radical surgical treatment of thyroid cancer in patients of pensionage and advanced age based on active diagnostic tactics and a differentiated approach to the volume of operative intervention.

TASKS OF THE RESEARCH:

1) To conduct a comparative evaluation of "active" and "passive" diagnostic tactics in patients of pensionage and advanced age for the detection of thyroid cancer in early stages (T1–T2).

2) To investigate the structure of thyroid gland diseases preceding cancer depending on the age of patients and their region of residence.

3) To evaluate at the preoperative stage the reliability of fine-needle aspiration biopsy with the application of ultrasound control and without it in patients with thyroid cancer over 60 years of age.

4) To compare the structure of histological types of thyroid cancer and the dependence on the region of residence (Smolensk or Bryansk region) and the age of patients.

5) To determine the optimal volumes of surgical treatment taking into account the histological type and spread of the primary tumor in patients with thyroid cancer over 60 years of age.

6) To study the structure of postoperative complications in patients with thyroid cancer over 60 years of age and young age.

7) To identify the possibilities of performing repeat surgical interventions in case of recurrence of thyroid cancer in patients of pensionage and advanced age.

THE MAIN PROVISIONS SUBMITTED FOR DEFENSE:

1) The "active" diagnostic tactics, compared to the "passive" ones, contribute to the improvement of the detection rate of thyroid cancer in patients of pensionage and advanced age at the stage T1–T2 by 1.9 times (86.7% and respectively).

2) The performance of fine-needle capillary puncture of nodular formations of the thyroid gland under ultrasound control in persons over 60 years of age at the preoperative stage allows to correctly set the morphological diagnosis with an indication of the histological type of cancer 1.6 times more often than without ultrasound control.

3) In patients with thyroid cancer, the frequency of detection of various histological types depends on age, but does not depend on the region (Smolensk or Bryansk region) of residence.

4) In papillary (T1) and follicular (T2–T3) thyroid cancer, the optimal volume of surgical treatment is hemithyroidectomy-depression. In patients of pensionage and advanced age, resection of a lobe of the thyroid gland is not a radical operation.

5) In highly differentiated forms (papillary and follicular) of thyroid cancer in patients of pensionage and advanced age, repeat surgical treatment is possible with favorable late results.

THE SCIENTIFIC NOVELTY OF THE RESEARCH:

1) It has been first revealed that regardless of age and region of residence, in the structure of benign diseases of the thyroid gland preceding cancer, nodular toxic goiter (78.6%) prevails in patients of pensionage and advanced age living in conditionally "clean" territories; this disease is encountered more often (78.6%) than in radioactively contaminated territories (6.4%). Diffusive toxic goiter of the thyroid gland in patients with thyroid cancer of pensionage and advanced age is more often encountered in radioactively contaminated territories (22.3%) than in conditionally "clean" ones (7.1%).

2) It is proven that in patients with thyroid cancer, the structure of histological types of the tumor does not depend on the region of residence (radioactively contaminated Bryansk or conditionally "clean" Smolensk region), but depends on age.

3) It has been first established that the frequency of the development of hypoparathyroidism in patients with thyroid cancer over 60 years of age after thyroidectomy is higher than in young patients.

THE PRACTICAL SIGNIFICANCE OF THE RESEARCH:

1) The use of "active" diagnostic tactics compared to "passive" ones in persons over 60 years of age with benign diseases of the thyroid gland contributes to the earlier detection of thyroid cancer.

2) The optimal volumes of radical surgical intervention on the thyroid gland are substantiated in patients with highly differentiated forms of thyroid cancer over 60 years of age depending on the spread of the primary tumor. It is proven that in patients of pensionage and advanced age, resection of a lobe of the thyroid gland is not a radical operation.

3) The possibilities of performing repeat operative interventions in case of recurrence of highly differentiated forms (papillary and follicular) of thyroid cancer in patients of pensionage and advanced age have been determined.

RESEARCH PROTECTION: The main provisions of the work were reported and discussed at: 3rd Congress of Oncologists and Radiologists of the CIS, Minsk, 2004; Russian Scientific Conference "Medical and Biological Problems of Radiation and Chemical Protection", St. Petersburg, 2004; session of the regional scientific society of surgeons named after N.I. Pregov, Smolensk, 2004; 9th International Scientific and Practical Conference "Elderly Patient. Quality of Life", Moscow, 2004; interregional scientific and practical conference "Actual problems of pharmacological treatment of malignant tumors", Smolensk, 2004.

IMPLEMENTATION OF THE RESEARCH: The provisions of the dissertation, methods of functional examination, algorithms of diagnostic and therapeutic measures have been introduced into practical work at the Smolensk Regional Clinical Hospital, the Bryansk Regional Oncological Dispensary, the Bryansk Regional Diagnostic and Treatment Center, the Kaliningrad Regional Oncological Dispensary. The main provisions of the dissertation are included in the lecture course and methodological developments of the Department of Faculty Surgery of the Smolensk State Medical Academy.

PUBLICATIONS: 20 printed works have been published on the topic of the dissertation.

STRUCTURE AND VOLUME OF THE DISSERTATION: The work is presented on 134 pages of typed text, consists of an introduction, 4 chapters, discussion of the results and conclusions, practical recommendations, reference list containing 102 domestic and 71 foreign authors. The work is formatted with 52 tables and 3 figures.