Microinvasive breast cancer and the role of sentinel lymph node biopsy.

Whether sentinel lymph node biopsy (SLNB) should be performed in patients with microinvasive breast cancer (MIBC) has been a matter of debate over the last decade. MIBC has a favorable prognosis and while metastasis to the axilla is rare, it can impact treatment recommendations. In this study we evaluated clinical and histological features in both MIBC and background DCIS including ER, PR, and HER-2, number of foci of MIBC, the extent of the DCIS, nuclear grade, presence of comedo necrosis, as well as surgical procedures, adjuvant treatment and follow up to identify variables which predict disease free survival (DFS), as well as the factors which influence clinical decision making. Our study included 72 MIBC patients with a mean patient follow-up time of 55 months. Three patients with MIBC had recurrence, and two deceased, leaving five patients in total with poor long-term outcomes and a DFS rate of 93.1%. Performing mastectomy, high nuclear grade, and negativity for ER and HER-2 were found to be associated with the use of SLNB, although none of these variables were found to be associated with DFS. One positive lymph node case was discovered following SLNB in our study. This suggests the use of SLNB may provide diagnostic information to some patients, although these are the anomalies. When comparing patients who had undergone SLNB to those which had not there was no difference in DFS. Certainly, the use of SLNB in MIBC is quite the conundrum. It is important to acknowledge that surgical complications have been reported, and traditional metrics used for risk assessment in invasive breast cancer may not hold true in the setting of microinvasion.

Molecular Mechanism(s) Involved in 25-Hydroxyvitamin D's Antiproliferative Effects in CYP27B1-transfected LNCaP Cells.

BACKGROUND/AIM: 1α,25(OH)2D has been shown to induce cell-cycle regulation, apoptosis and differentiation in prostate cancer cells. Previous studies have demonstrated that prostate and some prostate cancer cells have the ability to convert 25(OH)D3 to 1α,25(OH)2D3. The aim of the present study was to elucidate the role of 1α,25(OH)2D3 production by 25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) on prostate cancer cell growth. MATERIALS AND METHODS: LNCaP cells were stably transfected with CYP27B. RESULTS: Stably-transfected 1α-OHase LNCaP cells converted 25(OH)D3 to 1α,25(OH)2D3 unlike untransfected LNCaP cells. There was a dose-dependent decrease in (3)H-thymidine incorporation in 1α,25(OH)2D3-treated LNCaP cells, not seen with 25(OH)D3 treatment, and in stably transfected 1α-OHase LNCaP cells treated with 25(OH)D3. 1α,25(OH)2D3-treated LNCaP cells and 25(OH)D3-treated stably-transfected 1α-OHase LNCaP cells demonstrated an increased G1 phase accumulation and apoptosis, while 25(OH)D3 treatment had no effect in LNCaP cells. CONCLUSION: The present study supports the hypothesis that local production of 1α,25(OH)2D is important in inhibiting prostate cancer development and growth.

Effect of dietary vitamin D and calcium on the growth of androgen-insensitive human prostate tumor in a murine model.

Vitamin D deficiency has been associated with increased risk of prostate cancer (PC) in epidemiologic and prospective studies. An association has also been made between high dietary calcium and increased PC risk. In this study, we evaluated the effect of dietary vitamin D and calcium on the growth of human androgen-insensitive prostate tumor in an athymic mouse model. We observed highest tumor growth in the normal calcium - vitamin D-deficient group, while tumor growth between the normal calcium - vitamin D-sufficient, high calcium - vitamin D-sufficient and high calcium - vitamin D-deficient diet-groups did not significantly differ but was significantly lower than that in the normal calcium - vitamin D-deficient group. Our results suggest an important role of dietary vitamin D as a preventive agent in androgen-insensitive PC.