ABSTRACT
The aim of this investigation is to study the number of circulating tumor cells (CTCs) in the blood of cancer patients after systemic photodynamic therapy (PDT) at different times and to assess apoptosis of these cells. The study group consisted of 19 patients with malignant tumors of epithelial origin at various stages (II-IV). CTC identification was performed with flow cytometry by immunophenotype Ep-CAM (CD326)+ CD45-. CTC apoptosis was identified by criteria of plasma membrane integrity and phosphatidylserine translocation on the outer surface of the membrane. Negative correlation between the CTC frequency and apoptotic death rate of these cells was found in patients before the treatment (R = -0.51, p = 0.03). CTC frequency gradually reduced during the first three days after PDT, and then it was maintained at the same level until the end of the follow-up (7 days). At the individual level, the effect of PDT depended on the frequency of CTCs before the treatment: the decrease in these cell frequency occurred significantly more often in the patients with an initially high frequency of CTCs than in other patients (p = 0.05). With the decrease in the CTC frequency, apoptotic death increased within 6 hours after the treatment and remained at the same level until the end of the follow-up period. The results demonstrate the efficacy of systemic PDT for elimination of tumor cells circulating in the peripheral blood of cancer patients with different localization of primary tumor and stage of disease.
Subject(s)
Breast Neoplasms/therapy , Lung Neoplasms/therapy , Neoplastic Cells, Circulating/radiation effects , Photochemotherapy , Adult , Aged , Apoptosis/radiation effects , Breast Neoplasms/pathology , Cell Count , Female , Flow Cytometry , Humans , Lung Neoplasms/pathology , Male , Middle AgedABSTRACT
We carried out the first investigation to establish rat tumor M-1 by laser irradiation of the large blood vessel zone in the inguinal triangle in conjunction with photosensitinogen growth inhibition. Relatively small-size metastases to the lymph nodes and liver (stage III-IV) were identified after the blood was exposed to laser radiation in combination with intravenous injection of photosensitinogen under clinical conditions.
