Expression of thymidine phosphorylase as an effect prediction factor for uterine cervical squamous cell carcinoma after radiotherapy: an immunohistochemical study

The effect of chemotherapy or radiotherapy on thymidine phosphorylase and dihydropyrimidine dehydrogenase expression in cancer of the uterine cervix

OBJECTIVE

Levels of 5-FU metabolic or related enzymes, particularly thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD), have been investigated in various cancer types, including uterine cervical cancer. Intratumoral TP levels have been reported to increase in response to several chemotherapeutic agents or irradiation in both xenografts and clinical studies. In cervical cancer, however, only a few studies about changes in TP and DPD expression associated with cancer treatment have been published. We evaluated the effect of chemotherapy and/or irradiation on TP and DPD expression in cervical squamous cell carcinoma.

STUDY DESIGN

Of 27 patients in this study, 12 patients underwent neoadjuvant chemotherapy consisting of nedaplatin, ifosfamide, and/or peplomycin followed by radical surgery, and 15 patients underwent radiotherapy (n=8) or chemoradiotherapy with nedaplatin (n=7) as initial treatment. Tumor specimens were obtained from biopsies acquired before treatment and after administration of chemotherapy (2 weeks after the first and second cycles), and after irradiation with 10 Gy, 20 Gy, and 30 Gy. These specimens were used to measure TP and DPD levels by ELISA.

RESULTS

In the 12 patients who received neoadjuvant chemotherapy, intratumoral TP and DPD levels did not change. In contrast, in the 15 patients who underwent radiotherapy or chemoradiotherapy with nedaplatin, TP or DPD expression appeared to be slightly increased or decreased, respectively, after irradiation with 20 Gy, and consequently the TP/DPD ratio was significantly higher after irradiation with 20 Gy than before irradiation.

CONCLUSIONS

These results suggest a clinical advantage of chemoradiotherapy with capecitabine or doxyfluridine over radiotherapy alone via the elevation of the TP/DPD ratio in cervical squamous cell carcinoma. However, no advantage of combination chemotherapy with these 5-FU derivatives was demonstrated. Therefore, further evaluation with a larger number of patients or with other chemotherapeutic agents is required to confirm these observations.

Clinical significance of PD-ECGF expression in human pancreatic carcinoma

AIM: To investigate the expression of platelet-derived endothelial cell growth factor (PD-ECGF) in human pancreatic carcinoma and evaluate its clinical significance.

METHODS: Immunohistochemistry was used to detect the expression of PD-ECGF in 36 paraffin-embedded pancreatic carcinoma specimens, 21 tumor-adjacent normal tissue specimens, and 60 cancerous specimens derived from other tissues (stomach, colon, esophagus, liver, lung and breast; 10 specimens each). The expression of PD-ECGF in different tissues was compared. The correlation between PD-ECGF expression and clinical parameters in pancreatic carcinoma was analyzed.

RESULTS: The positive rate of PD-ECGF in pancreatic carcinoma was higher than that in tumor-adjacent normal tissue (88.9% vs 28.6%, P < 0.01). The positive rates of PD-ECGF in cancerous colon, liver, breast, esophagus, stomach and lung tissues were 60%, 70%, 80%, 90%, 90% and 80%, respectively. The positive rate of PD-ECGF in pancreatic carcinoma at stage II-IV was higher than that at stage I (100% vs 75%, P < 0.05).

CONCLUSION: PD-ECGF is an organ-unspecific tumor-associated protein that may be associated with the progression of pancreatic carcinoma.

The cytosol activity of thymidine phosphorylase in endometrial cancer

BACKGROUND

Thymidine phosphorylase (TP) is identical with platelet-derived endothelial cell growth factor (PD-ECGF) which promotes angiogenesis. The aim of this study was to evaluate the cytosol activity of TP in tumor samples from patients with endometrial cancer.

METHODS

The activity of TP was measured by the spectrophotometric method in the cytosol of endometrial tumor samples from 43 patients. Moreover, the expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) protein and microvessel density (MD) were examined in the same endometrial tumor samples by immunohistochemical staining. Normal endometrium from 16 women, treated surgically due to nononcological reasons served as a control.A relationship between the cytosol TP activity, PD-ECGF/TP protein expression, MD and clinicopathologic features was investigated.

RESULTS

A significantly higher the cytosol TP activity, PD-ECGF/TP protein expression and MD was stated in malignant tumor samples when compared to the control (samples of normal endometrium). A positive statistically significant correlation between the cytosol enzyme activity and PD-ECGF/TP protein expression and MD was found, but weaker from the remaining ones between PD-ECGF/TP protein expression and MD was observed.Besides no correlation between the cytosol TP activity, PD-ECGF/TP protein expression as well as MD and grading or histopatological type of endometrial cancer was stated.

CONCLUSION

The cytosol TP activity in endometrial cancer is significantly higher than in normal endometrium, with no relation as to the stage and grade of tumors, but correlates with the PD-ECGF/TP protein expression and MD may therefore be associated with favorable prognosis in patients treated with chemo- or radiotherapy after surgery.