The effect of metformin on apoptosis in a breast cancer presurgical trial.

BACKGROUND: Metformin has been associated with antitumour activity in breast cancer (BC) but its mechanism remains unclear. We determined whether metformin induced a modulation of apoptosis by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) overall and by insulin resistance status in a presurgical trial. METHODS: Apoptosis was analysed in core biopsies and in surgical samples from 100 non-diabetic BC patients participating in a randomised trial of metformin vs placebo given for 4 weeks before surgery. RESULTS: Eighty-seven subjects (45 on metformin and 42 on placebo) were assessable for TUNEL measurement at both time points. TUNEL levels at surgery were higher than that at baseline core biopsy (P<0.0001), although no difference between arms was noted (metformin arm: median difference surgery-biopsy levels +4%, interquartile range (IQR): 2-12; placebo arm: +2%, IQR: 0-8, P=0.2). Ki67 labelling index and TUNEL levels were directly correlated both at baseline and surgery (Spearman's r=0.51, P<0.0001). In the 59 women without insulin resistance (HOMA index<2.8) ,there was a higher level of TUNEL at surgery on metformin vs placebo (median difference on metformin +4%, IQR: 2-14 vs +2%, IQR: 0-7 on placebo), whereas an opposite trend was found in the 28 women with insulin resistance (median difference on metformin +2%, IQR: 0-6, vs +5%, IQR: 0-15 on placebo, P-interaction=0.1). CONCLUSION: Overall, we found no significant modulation of apoptosis by metformin, although there was a trend to a different effect according to insulin resistance status, with a pattern resembling Ki67 changes. Apoptosis was significantly higher in the surgical specimens compared with baseline biopsy and was directly correlated with Ki67. Our findings provide additional evidence for a dual effect of metformin on BC growth according to insulin resistance status.

Breast cancer subtypes and outcome after local and regional relapse.

BACKGROUND: To evaluate the outcome of breast cancer patients after locoregional recurrence (LRR) according to tumor biological features evaluated at first diagnosis and at the time of recurrence. PATIENTS AND METHODS: We collected information on all consecutive breast cancer patients operated at the European Institute of Oncology between 1994 and 2005. The tumor characteristics and subsequent outcome of patients who experienced LRR were analyzed. RESULTS: Two hundred and seventy nine patients with LRR were identified, 197 and 82 patients with local and regional recurrence respectively. The overall discordance rate between primary cancer and LRR was 9% for estrogen receptor expression, 22% for progesterone receptor and 4% for human epidermal growth factor receptor 2. For patients with regional recurrence, the risk of distant metastasis was significantly higher compared with local relapse in case of late recurrence (hazard ratio [HR] = 2.76; 95% CI 1.31-5.85). Patients with triple-negative breast cancer at LRR experienced a higher risk of subsequent relapse (HR 2.87 [1.67-4.91]) and death (HR 2.00 [1.25-3.19]). CONCLUSION: LRR correlates with a high risk of subsequent events and death in particular in patients with triple-negative subtype.

Expression of ER, PgR, HER1, HER2, and response: a study of preoperative chemotherapy.

PURPOSE: To identify the role of estrogen (ER), progesterone (PgR), epidermal growth factor 1 (HER1), and HER2 receptors in predicting response to preoperative chemotherapy. MATERIALS AND METHODS: We reviewed the pretreatment biopsies of 485 patients with locally advanced breast cancer (cT2-T4, N0-2, M0) treated with preoperative chemotherapy. The incidence of pathological complete remission (pCR) and outcome were assessed with respect to clinical and pathological findings including ER/PgR status (absent versus expressed), HER1 (absent versus expressed) and HER2 (overexpressed versus none) expression. RESULTS: Patients with ER/PgR-absent tumors were 12.0 times [95% confidence interval (CI) 4.93-29.28] more likely to achieve a pCR (P < 0.0001). Predictors of disease-free survival (DFS) at the univariate analysis included HER1 [hazards ratio (HR) 1.6, 95% CI 1.04-2.32, P = 0.03] and HER2 (HR 1.6, 95% CI 1.08-2.38, P = 0.02) expression. A statistically significant difference in DFS was confirmed at the multivariate analysis for patients with ER/PgR-absent disease (HR 2.1, 95% CI 1.41-2.99, P = 0.0002). CONCLUSIONS: The pCR rate is higher and outcome worse for patients with ER/PgR-absent tumors. HER1 and HER2 expression may have a prognostic role in locally advanced breast cancer and warrant further studies.

Long-term follow-up of 5262 breast cancer patients with negative sentinel node and no axillary dissection confirms low rate of axillary disease.

AIM: It is established that axillary dissection (AD) can be safely avoided in breast cancer patients with a negative sentinel node (SN). In the present study we assessed whether the rate of axillary disease was sufficiently low on long term follow-up to consolidate the policy of AD avoidance. METHODS: We retrospectively analysed data on 5262 consecutive primary breast cancer patients with clinically negative axilla and negative SN, treated from 1996 to 2006, who did not receive AD. We used univariate and multivariate analyses to assess the influence of patient and tumour characteristics on first events and survival. The primary endpoint was the development of axillary disease as first event. RESULTS: After a median follow-up of 7.0 years (interquartile range 5.4-8.9 years) survival for the series was high (91.3%; 95% CI 90.3-92.3 at 10 years) and only 91 (1.7%) patients developed axillary disease as first event. Axillary disease was significantly more frequent in patients with the following characteristics: <35 years at diagnosis, tumour >1 cm, multifocality/multicentricity, G3, ductal histotype, Ki67 ≥ 30%, peritumoral vascular invasion, luminal B-like subtype, HER2 positivity, mastectomy, and not receiving radiotherapy. CONCLUSION: Long-term follow-up of our large series confirms that axillary metastasis is infrequent when AD is omitted in SN-negative breast cancer patients, and has low impact on overall survival.

Antitumour and biological effects of letrozole and GnRH analogue as primary therapy in premenopausal women with ER and PgR positive locally advanced operable breast cancer.

Preoperative endocrine therapy is effective in postmenopausal patients with breast cancers expressing oestrogen receptor. We investigated the activity of primary therapy with letrozole in combination with GnRH analogue in premenopausal women with T2-T4 N0-N2 breast cancer, whose tumours expressed oestrogen and progesterone receptors. We measured the expression of molecular factors involved in responsiveness to endocrine agents including ERalpha, EGFR, HER2, MAP kinases (and phosphorylated forms) ER-beta1, both at initial biopsy and at the time of surgery. Thirty-five patients were included and 32 patients were evaluable for response. Sixteen patients (50%, 95% CI 32-68%) obtained a partial response, 16 patients were stable. One patient showed pathological complete response (3%, 95% CI 0-16%). Response was significantly associated with younger age (P<0.05) and a longer duration of treatment (P<0.05). Treatment significantly decreased ERalpha-p-Ser(118) and upregulated ER-beta1, independently of response. No or negligible overexpression of EGFR was observed at baseline or after treatment in this population. Preoperative letrozole and GnRH analogue are effective in premenopausal women. A biological response in terms of downregulation of phosphorylated ERalpha was observed in all patients. Future investigations might focus on treatments of longer duration.