RELATIONSHIP BETWEEN LIFE EXPECTANCY AND TREATMENT OPTION FOR SMALL CELL LUNG CANCER

22nd subgroup – surgery (without mediastinal lymph node dissection), 4 courses of postoperative polychemotherapy and external beam radiotherapy – in 81 (9.5%); 33rd subgroup – 3–4 courses of preoperative polychemotherapy, surgery with mediastinal lymph node dissection, postoperative polychemotherapy 2–4 courses – in 27 (3.1%). Among the patients there were 809 (94.9%) men and 43 (5.1%) women. The predominating groups were patients aged: 50–59 years – 249 persons (29.2%) and 60–69 years – 314 patients (36.8%). The largest number of patients were in stage IIIA (299 persons, 35.1%), and a slightly smaller number of patients with stage IIIB (194 persons, 22.7%) Results.


INTRODUCTION
Small-cell lung carcinoma (SCLC) is a highly aggressive primary disseminated malignant tumor with quick double volume increase (on average, 33 days) and early metastasis. The unfavorable clinical prognosis for this disease provided grounds for the classification of small-cell carcinoma into a separate group [1].
Unsatisfactory results of treatment associated with tumor resistance to antitumor drugs made researchers study different chemotherapy plans with new drugs and indicate drugs in high doses with further bone marrow transplantation [2].
During the past decade, new diagnostic medical technology and chemotherapy drugs were introduced for the treatment of malignant tumors. Oncologists that treat lung cancer looked into the problem of lung cancer therapy from a different point of view reconsidering the role of surgery in the treatment of this group of patients [3].
The medical society has a positive attitude toward the resection of the primary tumor with mediastinal lymph node dissection with further adjuvant polychemotherapy with modern drugs because it favorably influences the life expectancy of patients [4].
The analysis of surgical treatment for SCLC showed its effectiveness in patients with a local primary process in the lungs (T1-2, N1-2) in combination with 4 courses of polychemotherapy in the early postoperative period. Such complex treatment provided 5-year survival in 10-50% of patients [5,6].
Radical resection of the primary tumor of lungs together with regional lymph nodes [7,8] provides "complete remission" and allows oncologists to exclude postoperative mediastinum radiotherapy from the treatment plan [9].
Indication of preoperative polychemotherapy to patients with SCLC is aimed at achieving maximum effect (complete tumor regression). The resected primary tumor allows doctors to study the pathomorphological resorption and evaluate the effectiveness of the performed neoadjuvant chemotherapy. The most favorable prognostic factor that directly affects the survival of patients is the complete resection of the tumor. Incomplete resection of the tumor requires the indication of chemotherapy with reserve-line drugs in the postoperative period [10].
The study was aimed to evaluate the life expectancy of patients with small-cell lung carcinoma depending on the method of treatment and the effectiveness of the surgical intervention at these stages of small-cell lung carcinoma and preoperative chemotherapy in patients with process stages IIB, IIIA, and IIIB.

MATERIALS AND METHODS.
The study was based on the medical data of 852 patients with small-cell lung carcinoma that underwent treatment in the Altay regional oncologic center from 1995 to 2015.
The study protocol followed guidelines for experimental investigation with human subjects in accordance with the Declaration of Helsinki and was approved by the ethics committee. Written informed consent was obtained from each patient (or an official representative) before the study.
All patients were divided into 3 groups: In Group I, there were fewer patients with stage IA than in Groups II and III. In Group II, there were more patients with stage IB than in Groups I and III. In Group II, 9.5% of patients had stage IIB, 20.5% of patients had stage IIIA, and 7.4% of patients had stage IIIB, which was significantly more than in Groups I and III.
Among patients with stage IIB, there was a similar amount of patients with T2N1M0 and T3N0M0.
Among patients with IIIA, patients with T3N1M0 and T3N2M0 prevailed. Among patients with IIIB, patients with any TN3M0 were registered 2 times more often.
Metastases were revealed in 670 patients (78.6%): 642 patients (75.3%) had metastasis to regional lymph nodes and 28 patients (3.3%) had remote metastasis. which was 19.6 months longer than in Group II and 24.2 months longer than in Group I ( Table 2).   In patients with stage T1N0-2, life expectancy up to 9 months was observed in 100% of cases. In patients with T1N0-1, it remained to 12 months, in T1N0to 18 months, which was by 23.5% longer than in patients with T1N1 and by 40.0% than in patients with T1N2. Life expectancy from 19 to 24 months in patients with T1N0 was observed in 75.0% of cases, which was shorter by 1.5% than in patients with T1N1 (76.5%) and longer by 35.0% than in patients with T1N2. Life expectancy in patients with T1N1 was longer by 36.5% than in patients with T1N2 (the difference was statistically significant) (<0.01). Life expectancy for more than 24 months was registered only in patients with T1N0-1; its ratio corresponded to a period of 19 to 24 months.
The mean (average) life expectancy in patients from this group is greatly influenced by metastases to the regional lymph nodes. Thus, the mean life expectancy in patients with T1N0 was 68.5 months, which was longer by 26.7 months or by 1.6 times than in patients with T1N1.
Metastases to mediastinal lymph nodes (N2) reduced the mean life expectancy by 47.1 months or by 3.2 times in comparison with patients with T1N0 and by 20.4 months or 1.9 times in comparison with patients with T1N1 (Table 5). The longest life expectancy was observed in patients with T2N0 -29.3 months, which was longer by 4.8 months than in patients with T2N1 and by 10.8 than in patients with T2N2 (Table 6). It can be seen that metastasis to regional lymph nodes in patients with T2 has a less significant influence than the size of the primary tumor in the lung. In patients with metastasis to regional lymph nodes N1, the mean life expectancy can be shorter by 1.2 times than in patients with N0 and longer by 1.3 times than in patients with N3. Mean (average)) life expectancy in patients with N0 is longer by 1.6 times than in patients with N2.
All patients with primary lung tumor process T3N0-2 had life expectancy up to 3 months in 100% of cases. Significant differences in this group of patients start to appear within the period from 10 to 12 months. Life expectancy in patients with T3N0 was 75.0%, which was by 25.0% longer than in patients with T3N1 and by 41.7% than in patients with T3N2. The longest life expectancy (more than 24 months) was observed in patients with tumor stage T3N0 (in 25.0% of patients), which was by 8.3% longer than in patients with T3N1 and by 16.7% longer than in patients with T3N2 (the differences were statistically significant).
Mean life expectancy in patients with T3N0 was 19.4 months, which was by 3 months longer than in patients with T3N1 and by 9 months longer than in patients with T3N2 (Table 7). tumor was used for the pathomorphological study. In 9 patients (33.3%), tumor pathomorphism of the 2nd-3rd degree was revealed, which allowed the authors to indicate these patients 2 courses of chemotherapy analogic to the pre-operative courses. When tumor pathomorphism was lower than the 2nd-3rd degree, 4 courses of chemotherapy with reserve-line drugs were performed in the postoperative period. These patients had tumor recurrence in the supraclavicular lymph nodes in 2 cases (7.4%) within the period from 19 to 24 months, which provided grounds for radical excision of the neck. Because of complete lymph node dissection, these patients were not indicated remote radiotherapy in the postoperative period and this did not affect the quality of therapy.
Mean (average) life expectancy in this group of patients (Subgroup III) was 29.6 months, which corresponded to the mean (average) life expectancy in patients from Subgroup II with tumor stage T2N0 (29.3 months).

CONCLUSIONS.
The surgical method of treatment for small-cell lung carcinoma positively influenced the mean (average) life expectancy in patients from Group III. It was 26.4 months, which was longer than in Group II by 19.6 months and in Group I by 24.2 months.
The size of the primary tumor in the lung began to influence the mean life expectancy in patients with tumor stage T1-2 and metastasis to regional lymph nodesin patients with T2-3N1-2.
The selection of patients with tumor stages IIIA and IIIB for surgical treatment with preoperative chemotherapy and obligatory inclusion of mediastinal lymph dissection provided mean life expectancy in Subgroup III similar to the mean life expectancy in patients from Group II with IIA (T2N0).

FINANCIAL SUPPORT AND SPONSORSHIP
Nil.