Principles of treatment of small cell lung cancer

Surgical treatment is indicated only in the early stages of MRL (T1-2N0-1). It should be complemented by postoperative polychemotherapy (4 courses). This group of patients has a 5-year survival rate of 39%.

Radiation therapy leads to regression of the tumor in 60- 80% of patients, but in its own form it does not increase life expectancy due to the appearance of remote metastases.

Chemotherapy is the cornerstone of MRL treatment. Among active preparations we should mention: cyclophosphane, doxorubicin, vinctin, etoposide, topo-tecan, irinotecan, paclitaxel, docetaxel, gemcitabine, and vinorelbin. Their effectiveness in monotherapy varies from 25 to 50%. Table 1 presents schemes of modern combined chemotherapy MRL.

Treatment of patients with localized form of small cell lung cancer.

Principles of treatment of small cell lung cancer

The effectiveness of modern therapy of this form of MRL varies from 65% to 90%, with a complete regression of the tumor in 45-75% of patients and median survival of 18 – 24 months. Patients who started treatment in good general condition (PS 0-1) and responded to induction therapy have a 5-year chance of recurring survival.

In the localized form of MRL, chemotherapy (CT) is performed according to one of the above schemes (2-4 courses) in combination with radiation therapy (LT) on the area of the primary focus, lung root and mediastinum with a total focal dose of 30-45 Gy (50-60 Gy according to the iso effect). The beginning of radiation therapy should be as close to the beginning of chemotherapy as possible, i.e. it is best to start LT either on the background of 1-2 courses of chemotherapy, or after evaluation of the effectiveness of treatment of two courses of HT.

Patients who have achieved complete remission are recommended to perform preventive brain irradiation in the total dose of 30 Gy due to the high risk (up to 70%) of metastasis to the brain.

The median survival rate of patients with localized form of small cell lung cancer using combined treatment is 16-24 months, with a 2-year survival rate of 40-50% and a 5-year survival rate of 10%. In the group of patients who started treatment in good general condition, the possibility to achieve 5-year survival rate is 25%.

In metastatic lesions of bone marrow, remote lymph nodes, in metastatic pleuritis the main treatment method is chemotherapy. In metastatic lesions of mediastinum lymph nodes with compression syndrome of the upper vena cava it is advisable to use combined treatment (chemotherapy in combination with radiation therapy). In metastatic lesions of the bones, brain, adrenals, the method of choice is radiation therapy. In case of metastases to the brain, radiation therapy in the total focal dose (SOD) of 30 Gy allows to get a clinical effect in 70% of patients, and half of them register a complete regression of the tumor according to CT data. Recently, there have been reports about the possibility of using systemic chemotherapy for metastases in the brain. Table 2 presents the current treatment tactics for various forms of small cell lung cancer.

Therapeutic tactics in relapse of MRL

Principles of treatment of small cell lung cancer

Despite the high sensitivity to chemotherapy and radiation therapy MRL, this disease has a high rate of relapse, in which case the choice of drugs for chemotherapy second line depends on the level of response to the first line of treatment, the duration of the non-recidivocal interval and the localization of metastatic foci.

It is accepted to distinguish between patients with a sensitive relapse of MRL, ie had in the history of full or partial effect of the first line of chemotherapy and the presence of progression at least 3 months after the end of induction chemotherapy. In this case, it is possible to reuse the treatment scheme against which the effect was revealed. There are patients with refractory relapse, ie when there is a progression of disease in the first line of chemotherapy or less than 3 months after the end of the induction therapy. The disease prognosis in MRL patients is especially unfavorable for patients with refractory relapse – in this case, the median of survival after the diagnosis of relapse does not exceed 3-4 months. In the presence of a refractory relapse, it is reasonable to use previously unused cytostatics and / or their combinations.

Recently, new drugs in therapy of MRL have been studied and already used, including gemcita-bin, topotecan, vinorelbin, irinotecan, taxanes, and also targeting drugs.