Glutathione S-transferase Pi expression in invasive breast cancer and its relation with the clinical outcome

PURPOSE

Glutathione S-transferase (GST) is a cytosolic enzymatic system involved in cellular detoxifying process. In vitro studies have shown that the presence of this enzymatic system in breast carcinoma cells can accelerate the elimination of drugs commonly used in chemotherapy, thereby decreasing its efficacy. The aim of the present study was to evaluate the association between GST Pi expression by breast carcinoma cells and disease-free and overall survival.

METHODS

Ninety-five female patients with invasive breast carcinoma submitted to surgical treatment and adjuvant chemotherapy from January, 1995 to June, 1997 and followed until August, 2006 were evaluated. The expression of GST Pi in breast carcinoma cells, determined by immunohistochemistry, was correlated with several clinical and pathological parameters of prognostic significance.

RESULTS

There were 36 (37.9%) GST Pi-positive cases. GST Pi immunoexpression was not significantly correlated with patient's age, histological tumor type, clinical stage, hormone receptor status and survival. On the other hand, GST Pi positivity showed a significant correlation with a lower histological grade/C-erb-B2 negative breast carcinoma phenotype.

CONCLUSION

The findings suggest that GST Pi expression does not constitute a satisfactory prognostic factor in breast cancer.

Recovery of fertility after grafting of cryopreserved germinative tissue in female rabbits following radiotherapy

BACKGROUND

Many cancer survivors face infertility as a consequence of the aggressive treatment they must undergo. Cryopreservation of ovarian tissue before chemotherapy or radiotherapy may allow for tissue transplantation after the treatment, and restoration of fertility. We tested the potential of an orthotopic autografting of cryopreserved germinative tissue in female rabbits with ovarian failure following radiotherapy.

METHODS

Ten adult multiparous female rabbits were randomly allocated into two groups, five in group I (control) and five in group II (transplant). All rabbits underwent right oophorectomy with cryopreservation of the germinative tissue, followed by sterilization of the remaining left ovary by radiotherapy. Later, group II rabbits received in the irradiated left ovary an implant of the frozen germinative tissue from the right ovary, whose small pieces were freely spread intracortically in a procedure we named 'intracortical sowing of germinative tissue' (ISGT).

RESULTS

All group II rabbits conceived following spontaneous mating within 6 months of the transplant, whereas none of the remaining rabbits in group I had conceived up to 11 months after transplant.

CONCLUSIONS

This study suggests that fertility can be restored in rabbits by sowing cortical tissue in a previously irradiated ovary. The clinical feasibility of this technique remains to be determined.